Patent Application
20250151618
This application claims priority to and benefits of Korean Patent Application No. 10-2023-0117978 under 35 U.S.C. § 119, filed on Sep. 5, 2023, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.
The disclosure relates to a light emitting element, a fused polycyclic compound used in the light emitting element, and a display device including the light emitting element.
Active development continues for an organic electroluminescence display device as an image display device. In contrast to liquid crystal display devices and the like, an organic electroluminescence display device is a so-called self-luminescent display device in which holes and electrons respectively injected from a first electrode and a second electrode recombine in an emission layer, so that a luminescent material including an organic compound in the emission layer emits light to achieve display.
In the application of an organic electroluminescence element to a display device, there is a demand for an organic electroluminescence element having a low driving voltage, high luminous efficiency, and a long service life, and continuous development is required on materials for an organic electroluminescence element that are capable of stably achieving such characteristics.
In order to implement a highly efficient organic electroluminescence element, technologies pertaining to phosphorescence emission using triplet state energy, or to fluorescence emission using triplet-triplet annihilation (TTA) in which singlet excitons are generated by the collision of triplet excitons are being developed. Development is presently directed thermally activated delayed fluorescence (TADF) materials that use delayed fluorescence phenomenon.
It is to be understood that this background of the technology section is, in part, intended to provide useful background for understanding the technology. However, this background of the technology section may also include ideas, concepts, or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to a corresponding effective filing date of the subject matter disclosed herein.
The disclosure provides a light emitting element in which an element service life is improved.
The disclosure also provides a fused polycyclic compound capable of improving an element service life of a light emitting element.
The disclosure also provides a display device including the light emitting element in which the service life is improved, thereby having excellent display quality.
An embodiment provides a light emitting element which may include a first electrode, a second electrode disposed on the first electrode, and at least one functional layer disposed between the first electrode and the second electrode and including a first compound represented by Formula 1:
In Formula 1, R1 to R3 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms; a may be an integer from 0 to 3; b and c may each independently be an integer from 0 to 4; X may be O, S, or N(Rx2); Rx1 may be a group represented by Formula 2; and Rx2 may be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, or a group represented by Formula 2:
In Formula 2, Re may be a hydrogen atom or a deuterium atom; R4 may be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; Rz may be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms; d may be an integer from 0 to 4; ring A to ring H may each independently be a substituted or unsubstituted 5-membered heterocycle, a substituted or unsubstituted 6-membered heterocycle, or a substituted or unsubstituted 6-membered aromatic hydrocarbon ring; ring A to ring H may each independently be present or absent; a dashed line represents a bonding line, when each of ring A to ring H are absent, the group represented by Formula 2 may include an Rz group in place of a hydrogen atom at an ortho position with respect to ; and
is a position linked to Formula 1.
In an embodiment, the at least one functional layer may include an emission layer, a hole transport region disposed between the first electrode and the emission layer, and an electron transport region disposed between the emission layer and the second electrode; and the emission layer may include the first compound.
In an embodiment, ring A to ring H may each independently be a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, or a substituted or unsubstituted benzene ring.
In an embodiment, the group represented by Formula 2 may be a group represented by any one of Formula 2-1 to Formula 2-18:
In Formula 2-1 to Formula 2-18, Rf and Rg may each independently be a hydrogen atom or a deuterium atom; R5 and R6 may each independently be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; Rz1 to Rz18 is and Ra1 to Ra17 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms; d1 to d3 and d5 may each independently be an integer from 0 to 3; d4 and d6 to d18 may each independently be an integer from 0 to 2; m1 to m5 may each independently be an integer from 0 to 5; m6 to m17 may each independently be an integer from 0 to 4; and is a position linked to Formula 1.
In Formula 2-1 to Formula 2-18, Re and R4 are the same as defined in Formula 2.
In an embodiment, the first compound represented may be represented by Formula 3-1 or Formula 3-2:
In Formula 3-1 and Formula 3-2, X1 may be O or S; X2 may be N(Rx2′); and Rx2′ may be a group represented by Formula 4-1 or Formula 4-2:
In Formula 4-1 and Formula 4-2, Rh may be a hydrogen atom or a deuterium atom; Rb1 to Rb3 and Ry may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms; n1 and n3 may each independently be an integer from 0 to 5; n2 may be an integer from 0 to 3; R7 may be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; e may be an integer from 0 to 4; ring I to ring P may each independently be a substituted or unsubstituted 5-membered heterocycle, a substituted or unsubstituted 6-membered heterocycle, or a substituted or unsubstituted 6-membered aromatic hydrocarbon ring; ring I to ring P may each independently be present or absent; a dashed line represents a bonding line; and is a position linked to Formula 3-2.
In Formula 3-1 and Formula 3-2, R1 to R3, a to c, and Rx1 are the same as defined in Formula 1.
In an embodiment, the first compound may be represented by Formula 5-1 or Formula 5-2:
In Formula 5-1 and Formula 5-2, R3′ may be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms; c′ may be an integer from 0 to 3; and R3a and R3b may each independently be a group represented by Formula A-1 or Formula A-2:
In Formula A-1 and Formula A-2, Rc1 to Rc3 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstitutedheteroaryl group having 2 to 30 ring-forming carbon atoms; n11 may be an integer from 0 to 5; and n12 and n13 may each independently be an integer from 0 to 4.
In Formula 5-1 and Formula 5-2, R1, R2, a, b, X, and Rx1 are the same as defined in Formula 1.
In an embodiment, the first compound may be represented by any one of Formula 6-1 to Formula 6-4:
In Formula 6-1 to Formula 6-4, R2′, R3′, and Rd1 to Rd12 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms; b‘ and c’ may each independently be an integer from 0 to 3; n21 to n23 and n28 may each independently be an integer from 0 to 5; and n24 to n27 and n29 to n32 may each independently be an integer from 0 to 4.
In Formula 6-1 to Formula 6-4, X, R1, a, and Rx1 are the same as defined in Formula 1.
In an embodiment, the first compound may be represented by Formula 7:
In Formula 7, R1′ may be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms; a′ may be an integer from 0 to 2; and R1a may be a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms or a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms.
In Formula 7, R2, R3, b, c, X, and Rx1 are the same as defined in Formula 1.
In an embodiment, the first compound may be represented by Formula 8-1 or Formula 8-2:
In Formula 8-1 and Formula 8-2, Re′ may be a hydrogen atom or deuterium atom; R4′ may be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; Rz′ may be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted aryl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms; d′ may be an integer from 0 to 3; and Rx1′ may be a group represented by Formula 9:
In Formula 9, Rz″ may be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms; d″ may be an integer from 0 to 3; ring A′ to ring H′ may each independently be a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, or a substituted or unsubstituted benzene ring; at least one of ring A′ to ring H′ may each be present; the remainder of ring A′ to ring H′ may be absent; and is a position linked to Formula 8-2.
In Formula 9, R4 and Re are the same as defined in Formula 2.
In Formula 8-1 and Formula 8-2, X, Re, R1 to R4, and a to c are the same as defined in Formula 1 and Formula 2.
In an embodiment, the emission layer may further include at least one of a second compound represented by Formula HT-1, a third compound represented by Formula ET-1, and a fourth compound represented by Formula D-1:
In Formula HT-1, M1 to M8 may each independently be N or C(R51); L1 may be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms; Ya may be a direct linkage, C(R52)(R53), or Si(R54)(R55); Ara may be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms; R51 to R55 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms, or bonded to an adjacent group to form a ring.
In Formula ET-1, at least one of Za to Zc may each be N; the remainder of Za to Zc may each independently be C(R56); R56 may be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms; b1 to b3 may each independently be an integer from 0 to 10; Arb to Ard may each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms; and L2 to L4 may each independently be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon
In Formula D-1, Q1 to Q4 may each independently be C or N; C1 to C4 may each independently be a substituted or unsubstituted hydrocarbon ring having 5 to 30 ring-forming carbon atoms or a substituted or unsubstituted heterocycle having 2 to 30 ring-forming carbon atoms; L11 to L13 may each independently be a direct linkage, ,
.
a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms; b11 to b13 may each independently be 0 or 1; R61 to R66 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms; and e1 to e4 may each independently be an integer from 0 to 4.
An embodiment provides a display device which may include: a circuit layer disposed on a base layer; and a display element layer disposed on the circuit layer and including a light emitting element, wherein
the light emitting element may include a first electrode, a second electrode disposed on the first electrode, and an emission layer disposed between the first electrode and the second electrode and including a first compound represented by Formula 1, which is explained herein.
In an embodiment, the light emitting element may further include a capping layer disposed on the second electrode; and the capping layer may have a refractive index equal to or greater than about 1.6 with respect to light in a range of a wavelength of about 550 nm to about 660 nm.
In an embodiment, the display device may further include a light control layer disposed on the display element layer, wherein
the light emitting element may emit first color light; and the light control layer may include a first light control part including a first quantum dot that converts the first color light into second color light having a wavelength region that is longer than the first color light, a second light control part including a second quantum dot that converts the second color light into third color light having a longer wavelength region that is longer than the second color light, and a third light control part that transmits the first color light.
In an embodiment, the display device may further include a color filter layer disposed on the light control part, wherein
the color filter layer may include a first filter that transmits the second color light, a second filter that transmits the third color light, and a third filter that transmits the first color light.
An embodiment provides a fused polycyclic compound which may be represented by Formula 1, which is explained herein.
In an embodiment, the group represented by Formula 2 may be a group represented by any one of Formula 2-1 to Formula 2-18, which are explained herein.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 3-1 or Formula 3-2, which are explained herein.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 5-1 or Formula 5-2, which are explained herein.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by any one of Formula 6-1 to Formula 6-4, which are explained herein.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be selected from Compound Group 1, which is explained below.
It is to be understood that the embodiments above are described in a generic and explanatory sense only and not for the purposes of limitation, and the disclosure is not limited to the embodiments described above.
The accompanying drawings are included to provide a further understanding of the embodiments, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and principles thereof. The above and other aspects and features of the disclosure will become more apparent by describing in detail embodiments thereof with reference to the accompanying drawings, in which:
The disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments are shown. This disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
In the drawings, the sizes, thicknesses, ratios, and dimensions of the elements may be exaggerated for ease of description and for clarity. Like reference numbers and reference characters refer to like elements throughout.
In the specification, it will be understood that when an element (or region, layer, part, etc.) is referred to as being “on”, “connected to”, or “coupled to” another element, it can be directly on, connected to, or coupled to the other element, or one or more intervening elements may be present therebetween. In a similar sense, when an element (or region, layer, part, etc.) is described as “covering” another element, it can directly cover the other element, or one or more intervening elements may be present therebetween.
In the specification, when an element is “directly on,” “directly connected to,” or “directly coupled to” another element, there are no intervening elements present. For example, “directly on” may mean that two layers or two elements are disposed without an additional element such as an adhesion element therebetween.
As used herein, the expressions used in the singular such as “a,” “an,” and “the,” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. For example, “A and/or B” may be understood to mean “A, B, or A and B.” The terms “and” and “or” may be used in the conjunctive or disjunctive sense and may be understood to be equivalent to “and/or”.
In the specification and the claims, the term “at least one of” is intended to include the meaning of “at least one selected from the group consisting of” for the purpose of its meaning and interpretation. For example, “at least one of A, B, and C” may be understood to mean A only, B only, C only, or any combination of two or more of A, B, and C, such as ABC, ACC, BC, or CC. When preceding a list of elements, the term, “at least one of,” modifies the entire list of elements and does not modify the individual elements of the list.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, a first element could be termed a second element without departing from the teachings of the disclosure. Similarly, a second element could be termed a first element, without departing from the scope of the disclosure.
The spatially relative terms “below”, “beneath”, “lower”, “above”, “upper”, or the like, may be used herein for ease of description to describe the relations between one element or component and another element or component as illustrated in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, in the case where a device illustrated in the drawing is turned over, the device positioned “below” or “beneath” another device may be placed “above” another device. Accordingly, the illustrative term “below” may include both the lower and upper positions. The device may also be oriented in other directions and thus the spatially relative terms may be interpreted differently depending on the orientations.
The terms “about” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the recited value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the recited quantity (i.e., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations, or within ±20%, ±10%, or ±5% of the stated value.
It should be understood that the terms “comprises,” “comprising,” “includes,” “including,” “have,” “having,” “contains,” “containing,” and the like are intended to specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof in the disclosure, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.
Unless otherwise defined or implied herein, all terms (including technical and scientific terms) used have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and should not be interpreted in an ideal or excessively formal sense unless clearly defined in the specification.
In the specification, the term “substituted or unsubstituted” may describe a group that is substituted or unsubstituted with at least one substituent selected from the group consisting of a deuterium atom, a halogen atom, a cyano group, a nitro group, an amino group, an amine group, a silyl group, an oxy group, a thio group, a sulfinyl group, a sulfonyl group, a carbonyl group, a boron group, a phosphine oxide group, a phosphine sulfide group, an alkyl group, an alkenyl group, an alkynyl group, a hydrocarbon ring group, an aryl group, and a heterocyclic group. Each of the substituents listed above may itself be substituted or unsubstituted. For example, a biphenyl group may be interpreted as an aryl group, or it may be interpreted as a phenyl group substituted with a phenyl group.
In the specification, the term “bonded to an adjacent group to form a ring” may be interpreted as a group that is bonded to an adjacent group to form a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle. The hydrocarbon ring may be aliphatic or aromatic. The heterocycle may be aliphatic or aromatic. The hydrocarbon ring and the heterocycle may each independently be monocyclic or polycyclic. A ring that is formed by adjacent groups being bonded to each other may itself be connected to another ring to form a spiro structure.
In the specification, the term “adjacent group” may be interpreted as a substituent that is substituted for an atom which is directly linked to an atom substituted with a corresponding substituent, as another substituent that is substituted for an atom which is substituted with a corresponding substituent, or as a substituent that is sterically positioned at the nearest position to a corresponding substituent. For example, two methyl groups in 1,2-dimethylbenzene may be interpreted as “adjacent groups” to each other, and two ethyl groups in 1,1-diethylcyclopentane may be interpreted as “adjacent groups” to each other. For example, two methyl groups in 4,5-dimethylphenanthrene may be interpreted as “adjacent groups” to each other.
In the specification, examples of a halogen atom may include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
In the specification, an alkyl group may be linear or branched. The number of carbon atoms in an alkyl group may be 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of an alkyl group may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, a t-butyl group, an i-butyl group, a 2-ethylbutyl group, a 3,3-dimethylbutyl group, an n-pentyl group, an i-pentyl group, a neopentyl group, a t-pentyl group, a 1-methylpentyl group, a 3-methylpentyl group, a 2-ethylpentyl group, a 4-methyl-2-pentyl group, an n-hexyl group, a 1-methylhexyl group, a 2-ethylhexyl group, a 2-butylhexyl group, an n-heptyl group, a 1-methylheptyl group, a 2,2-dimethylheptyl group, a 2-ethylheptyl group, a 2-butylheptyl group, an n-octyl group, a t-octyl group, a 2-ethyloctyl group, a 2-butyloctyl group, a 2-hexyloctyl group, a 3,7-dimethyloctyl group, an n-nonyl group, an n-decyl group, an adamantyl group, a 2-ethyldecyl group, a 2-butyldecyl group, a 2-hexyldecyl group, a 2-octyldecyl group, an n-undecyl group, an n-dodecyl group, a 2-ethyldodecyl group, a 2-butyldodecyl group, a 2-hexyldocecyl group, a 2-octyldodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, a 2-ethylhexadecyl group, a 2-butylhexadecyl group, a 2-hexylhexadecyl group, a 2-octylhexadecyl group, an n-heptadecyl group, an n-octadecyl group, an n-nonadecyl group, an n-eicosyl group, a 2-ethyleicosyl group, a 2-butyleicosyl group, a 2-hexyleicosyl group, a 2-octyleicosyl group, an n-henicosyl group, an n-docosyl group, an n-tricosyl group, an n-tetracosyl group, an n-pentacosyl group, an n-hexacosyl group, an n-heptacosyl group, an n-octacosyl group, an n-nonacosyl group, an n-triacontyl group, etc., but embodiments are not limited thereto.
In the specification, a cycloalkyl group may be a cyclic alkyl group. The number of carbon atoms in a cycloalkyl group may be 3 to 50, 3 to 30, 3 to 20, or 3 to 10. Examples of a cycloalkyl group may include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a 4-methylcyclohexyl group, a 4-t-butylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a norbornyl group, a 1-adamantyl group, a 2-adamantyl group, an isobornyl group, a bicycloheptyl group, etc., but embodiments are not limited thereto.
In the specification, an alkenyl group may be a hydrocarbon group that includes at least one carbon-carbon double bond in the middle or at a terminus of an alkyl group having 2 or more carbon atoms. An alkenyl group may be linear or branched. The number of carbon atoms in an alkenyl group is not particularly limited, and may be 2 to 30, 2 to 20, or 2 to 10. Examples of an alkenyl group may include a vinyl group, a 1-butenyl group, a 1-pentenyl group, a 1,3-butadienyl aryl group, a styrenyl group, a styryl vinyl group, etc., but embodiments are not limited thereto.
In the specification, an alkynyl group may be a hydrocarbon group that includes at least one carbon-carbon triple bond in the middle or at a terminus of an alkyl group having 2 or more carbon atoms. An alkynyl group may be linear or branched. The number of carbon atoms in an alkynyl group is not particularly limited, and may be 2 to 30, 2 to 20, or 2 to 10. Examples of an alkynyl group may include an ethynyl group, a propynyl group, etc., but embodiments are not limited thereto.
In the specification, a hydrocarbon ring group may be any functional group or substituent derived from an aliphatic hydrocarbon ring. For example, a hydrocarbon ring group may be a saturated hydrocarbon ring group having 5 to 20 ring-forming carbon atoms.
In the specification, an aryl group may be any functional group or substituent derived from an aromatic hydrocarbon ring. An aryl group may be monocyclic or polycyclic. The number of ring-forming carbon atoms in an aryl group may be 6 to 60, 6 to 50, 6 to40, 6 to 30, 6 to 20, or 6 to 15. Examples of an aryl group may include a phenyl group, a naphthyl group, a fluorenyl group, an anthracenyl group, a phenanthryl group, a biphenyl group, a terphenyl group, a quaterphenyl group, a quinquephenyl group, a sexiphenyl group, a triphenylenyl group, a pyrenyl group, a benzofluoranthenyl group, a chrysenyl group, etc., but embodiments are not limited thereto.
In the specification, a fluorenyl group may be substituted, and two substituents may be bonded to each other to form a spiro structure. Examples of a substituted fluorenyl group may include the groups shown below. However, embodiments are not limited thereto.
In the specification, a heterocyclic group may be any functional group or substituent derived from a ring that includes at least one of B, O, N, P, Si, S, and Se as a heteroatom. A heterocyclic group may be aliphatic or aromatic. An aromatic heterocyclic group may be a heteroaryl group. An aliphatic heterocycle and an aromatic heterocycle may each independently be monocyclic or polycyclic.
In the specification, a heterocyclic group may include at least one of B, O, N, P, Si, S, and Se as a heteroatom. If a heterocyclic group includes two or more heteroatoms, the two or more heteroatoms may be the same as or different from each other. A heterocyclic group may be monocyclic or polycyclic, and a heterocyclic group may be a heteroaryl group. The number of ring-forming carbon atoms in a heterocyclic group may be 2 to 60, 2 to 50, 2 to 40, 2 to 30, 2 to 20, or 2 to 10.
In the specification, an aliphatic heterocyclic group may include at least one of B, O, N, P, Si, S, and Se as a heteroatom. The number of ring-forming carbon atoms in an aliphatic heterocyclic group may be 2 to 30, 2 to 20, or 2 to 10. Examples of an aliphatic heterocyclic group may include an oxirane group, a thiirane group, a pyrrolidine group, a piperidine group, a tetrahydrofuran group, a tetrahydrothiophene group, a thiane group, a tetrahydropyran group, a 1,4-dioxane group, etc., but embodiments are not limited thereto.
In the specification, a heteroaryl group may include at least one of B, O, N, P, Si, S, and Se as a heteroatom. If a heteroaryl group includes two or more heteroatoms, the two or more heteroatoms may be the same as or different from each other. A heteroaryl group may be monocyclic or polycyclic. The number of ring-forming carbon atoms in a heteroaryl group may be 2 to 60, 2 to 50, 2 to 40, 2 to 30, 2 to 20, or 2 to 10. Examples of a heteroaryl group may include a thiophene group, a furan group, a pyrrole group, an imidazole group, a pyridine group, a bipyridine group, a pyrimidine group, a triazine group, a triazole group, an acridyl group, a pyridazine group, a pyrazinyl group, a quinoline group, a quinazoline group, a quinoxaline group, a phenoxazine group, a phthalazine group, a pyrido pyrimidine group, a pyrido pyrazine group, a pyrazino pyrazine group, an isoquinoline group, an indole group, a carbazole group, an N-arylcarbazole group, an N-heteroarylcarbazole group, an N-alkylcarbazole group, a benzoxazole group, a benzoimidazole group, a benzothiazole group, a benzocarbazole group, a benzothiophene group, a dibenzothiophene group, a thienothiophene group, a benzofuran group, a phenanthroline group, a thiazole group, an isoxazole group, an oxazole group, an oxadiazole group, a thiadiazole group, a phenothiazine group, a dibenzosilole group, a dibenzofuran group, etc., but embodiments are not limited thereto.
In the specification, the above description of an aryl group may be applied to an arylene group, except that an arylene group is a divalent group. In the specification, the above description of a heteroaryl group may be applied to a heteroarylene group, except that a heteroarylene group is a divalent group.
In the specification, a silyl group may be an alkylsilyl group or an arylsilyl group. Examples of a silyl group may include a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, a propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, a phenylsilyl group, etc., but embodiments are not limited thereto.
In the specification, the number of carbon atoms in a carbonyl group is not particularly limited, and may be 1 to 40, 1 to 30, or 1 to 20. For example, a carbonyl group may have one of the following structures, but embodiments are not limited thereto.
In the specification, the number of carbon atoms in a sulfinyl group or in a sulfonyl group is not particularly limited, and may be 1 to 30. A sulfinyl group may be an alkyl sulfinyl group or an aryl sulfinyl group. A sulfonyl group may be an alkyl sulfonyl group or an aryl sulfonyl group.
In the specification, a thio group may be an alkylthio group or an arylthio group. A thio group may be a sulfur atom that is bonded to an alkyl group or an aryl group as defined above. Examples of a thio group may include a methylthio group, an ethylthio group, a propylthio group, a pentylthio group, a hexylthio group, an octylthio group, a dodecylthio group, a cyclopentylthio group, a cyclohexylthio group, a phenylthio group, a naphthylthio group, etc., but embodiments are not limited thereto.
In the specification, an oxy group may be an oxygen atom that is bonded to an alkyl group or an aryl group as defined above. An oxy group may be an alkoxy group or an aryl oxy group. An alkoxy group may be linear, branched, or cyclic. The number of carbon atoms in an alkoxy group is not particularly limited, and may be, for example, 1 to 20 or 1 to 10. Examples of an oxy group may include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a nonyloxy group, a decyloxy group, a benzyloxy group, etc., but embodiments are not limited thereto.
In the specification, a boron group may be a boron atom that is bonded to an alkyl group or an aryl group as defined above. A boron group may be an alkyl boron group or an aryl boron group. Examples of a boron group may include a dimethylboron group, a trimethylboron group, a t-butyldimethylboron group, a diphenylboron group, a phenylboron group, etc., but embodiments are not limited thereto.
In the specification, the number of carbon atoms in an amine group is not particularly limited, and may be 1 to 30. An amine group may be an alkyl amine group or an aryl amine group. Examples of an amine group may include a methylamine group, a dimethylamine group, a phenylamine group, a diphenylamine group, a naphthylamine group, a 9-methyl-anthracenylamine group, etc., but embodiments are not limited thereto.
In the specification, an alkyl group within an alkylthio group, an alkylsulfoxy group, an alkylaryl group, an alkylamino group, an alkyl boron group, an alkyl silyl group, or an alkyl amine group may be the same as an example of an alkyl group as described above.
In the specification, an aryl group within an aryloxy group, an arylthio group, an arylsulfoxy group, an arylamino group, an arylboron group, an arylsilyl group, or an arylamine group may be the same as an example of an aryl group as described above.
In the specification, a direct linkage may be a single bond.
In the specification, the symbols and
each represent a bond to a neighboring atom in a corresponding formula or moiety.
Hereinafter, embodiments will be described with reference to the accompanying drawings.
The display device DD may include a display panel DP and an optical layer PP disposed on the display panel DP. The display panel DP includes light emitting elements ED-1, ED-2, and ED-3. The display device DD may include multiples of each of the light emitting elements ED-1, ED-2, and ED-3. The optical layer PP may be disposed on the display panel DP to control light that is reflected at the display panel DP from an external light. The optical layer PP may include, for example, a polarization layer or a color filter layer. Although not shown in the drawings, in an embodiment, the optical layer PP may be omitted from the display device DD.
A base substrate BL may be disposed on the optical layer PP. The base substrate BL may provide a base surface on which the optical layer PP is disposed. The base substrate BL may be a glass substrate, a metal substrate, a plastic substrate, etc. However, embodiments are not limited thereto, and the base substrate BL may include an inorganic layer, an organic layer, or a composite material layer. Although not shown in the drawings, in an embodiment, the base substrate BL may be omitted.
The display device DD according to an embodiment may further include a filling layer (not shown). The filling layer (not shown) may be disposed between a display device layer DP-ED and the base substrate BL. The filling layer (not shown) may be an organic material layer.
The filling layer (not shown) may include at least one of an acrylic-based resin, a silicone-based resin, and an epoxy-based resin.
The display panel DP may include a base layer BS, a circuit layer DP-CL provided on the base layer BS, and the display device layer DP-ED. The display device layer DP-ED may include a pixel defining film PDL, light emitting elements ED-1, ED-2, and ED-3 disposed between portions of the pixel defining film PDL, and an encapsulation layer TFE disposed on the light emitting elements ED-1, ED-2, and ED-3.
The base layer BS may provide a base surface on which the display device layer DP-ED is disposed. The base layer BS may be a glass substrate, a metal substrate, a plastic substrate, etc. However, embodiments are not limited thereto, and the base layer BS may include an inorganic layer, an organic layer, or a composite material layer.
In an embodiment, the circuit layer DP-CL is disposed on the base layer BS, and the circuit layer DP-CL may include transistors (not shown). The transistors (not shown) may each include a control electrode, an input electrode, and an output electrode. For example, the circuit layer DP-CL may include a switching transistor and a driving transistor for driving the light emitting elements ED-1, ED-2, and ED-3 of the display device layer DP-ED.
The light emitting elements ED-1, ED-2, and ED-3 may each have a structure of a light emitting element ED of an embodiment according to any of
Although not illustrated in
The encapsulation layer TFE may cover the light emitting elements ED-1, ED-2, and ED-3. The encapsulation layer TFE may seal the display device layer DP-ED. The encapsulation layer TFE may be a thin film encapsulation layer. The encapsulation layer TFE may be formed of a single layer or of multiple layers. The encapsulation layer TFE may include at least one insulation layer. The encapsulation layer TFE according to an embodiment may include at least one inorganic film (hereinafter, an encapsulation-inorganic film). In an embodiment, the encapsulation layer TFE may include at least one organic film (hereinafter, an encapsulation-organic film) and at least one encapsulation-inorganic film.
The encapsulation-inorganic film protects the display device layer DP-ED from moisture and/or oxygen, and the encapsulation-organic film protects the display device layer DP-ED from foreign substances such as dust particles. The encapsulation-inorganic film may include silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, aluminum oxide, or the like, but embodiments are not limited thereto. The encapsulation-organic film may include an acrylic-based compound, an epoxy-based compound, or the like. The encapsulation-organic film may include a photopolymerizable organic material, but embodiments are not limited thereto.
The encapsulation layer TFE may be disposed on the second electrode EL2 and may be disposed to fill the openings OH.
Referring to
The light emitting regions PXA-R, PXA-G, and PXA-B may be regions that are separated from each other by the pixel defining film PDL. The non-light emitting regions NPXA may be areas between the adjacent light emitting regions PXA-R, PXA-G, and PXA-B, and which may correspond to the pixel defining film PDL. In an embodiment, the light emitting regions PXA-R, PXA-G, and PXA-B may each correspond to a pixel. The pixel defining film PDL may separate the light emitting elements ED-1, ED-2, and ED-3. The emission layers EML-R, EML-G, and EML-B of the light emitting elements ED-1, ED-2, and ED-3 may be disposed in openings OH defined in the pixel defining film PDL and separated from each other.
The light emitting regions PXA-R, PXA-G, and PXA-B may be arranged into groups according to the color of light generated from the light emitting elements ED-1, ED-2, and ED-3. In the display device DD according to an embodiment illustrated in
In the display device DD according to an embodiment, the light emitting elements ED-1, ED-2, and ED-3 may emit light having wavelengths that are different from each other. For example, in an embodiment, the display device DD may include a first light emitting element ED-1 that emits red light, a second light emitting element ED-2 that emits green light, and a third light emitting element ED-3 that emits blue light. For example, the red light emitting region PXA-R, the green light emitting region PXA-G, and the blue light emitting region PXA-B of the display device DD may respectively correspond to the first light emitting element ED-1, the second light emitting element ED-2, and the third light emitting element ED-3.
However, embodiments are not limited thereto, and the first to third light emitting elements ED-1, ED-2, and ED-3 may emit light in a same wavelength range, or at least one light emitting element may emit light in a wavelength range that is different from the remainder. For example, the first to third light emitting elements ED-1, ED-2, and ED-3 may each emit blue light.
The light emitting regions PXA-R, PXA-G, and PXA-B in the display device DD according to an embodiment may be arranged in a stripe configuration. Referring to
An arrangement of the light emitting regions PXA-R, PXA-G, and PXA-B is not limited to the configuration illustrated in
The areas of the light emitting regions PXA-R, PXA-G, and PXA-B may be different in size from each other. For example, in an embodiment, an area of a green light emitting region PXA-G may be smaller than an area of a blue light emitting region PXA-B, but embodiments are not limited thereto.
Hereinafter,
In an embodiment, the light emitting element ED may include a hole transport region HTR, an emission layer EML, an electron transport region ETR, or the like, as the at least one functional layer. In an embodiment shown in
In comparison to
A light emitting element ED according to an embodiment may include a fused polycyclic compound according to an embodiment, which will be explained later, in the at least one functional layer. In the light emitting element ED, at least one of the hole transport region HTR, the emission layer EML, and the electron transport region ETR may include the fused polycyclic compound according to an embodiment. For example, in the light emitting element ED, the emission layer EML may include the fused polycyclic compound.
The first electrode EL1 has conductivity. The first electrode EL1 may be formed of a metal material, a metal alloy, or a conductive compound. The first electrode EL1 may be an anode or a cathode. However, embodiments are not limited thereto. In an embodiment, the first electrode EL1 may be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a transflective electrode, or a reflective electrode. The first electrode EL1 may include at least one of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, Zn, an oxide thereof, a compound thereof, or a mixture thereof.
If the first electrode EL1 is a transmissive electrode, the first electrode EL1 may include a transparent metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium tin zinc oxide (ITZO). If the first electrode EL1 is a transflective electrode or a reflective electrode, the first electrode EL1 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF/Ca (a stacked structure of LiF and Ca), LiF/Al (a stacked structure of LiF and Al), Mo, Ti, W, a compound thereof, or a mixture thereof (e.g., a mixture of Ag and Mg). In another embodiment, the first electrode EL1 may have a multilayer structure including a reflective film or a transflective film formed of the above-described materials, and a transparent conductive film formed of ITO, IZO, ZnO, ITZO, etc. For example, the first electrode EL1 may have a three-layer structure of ITO/Ag/ITO, but embodiments are not limited thereto. In an embodiment, the first electrode EL1 may include the above-described metal materials, combinations of at least two metal materials of the above-described metal materials, oxides of the above-described metal materials, or the like. A thickness of the first electrode EL1 may be in a range of about 700 Å to about 10,000 Å. For example, the thickness of the first electrode EL1 may be in a range of about 1,000 Å to about 3,000 Å.
The hole transport region HTR may be provided on the first electrode EL1. The hole transport region HTR may include at least one of a hole injection layer HIL, a hole transport layer HTL, a buffer layer (not shown), an emission-auxiliary layer (not shown), and an electron blocking layer EBL. A thickness of the hole transport region HTR may be, for example, in a range of about 50 Å to about 15,000 Å.
The hole transport region HTR may be a layer consisting of a single material, a layer including different materials, or a structure including multiple layers including different materials.
In embodiments, the hole transport region HTR may have a single layer structure of a hole injection layer HIL or a hole transport layer HTL, or may have a single layer structure formed of a hole injection material and a hole transport material. In embodiments, the hole transport region HTR may have a single layer structure formed of different materials, or may have a structure in which a hole injection layer HIL/hole transport layer HTL, a hole injection layer HIL/hole transport layer HTL/buffer layer (not shown), a hole injection layer HIL/buffer layer (not shown), a hole transport layer HTL/buffer layer (not shown), or a hole injection layer HIL/hole transport layer HTL/electron blocking layer EBL are stacked in its respective stated order from the first electrode EL1, but embodiments are not limited thereto.
The hole transport region HTR may be formed using various methods such as a vacuum deposition method, a spin coating method, a cast method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, and a laser induced thermal imaging (LITI) method.
In the light emitting element ED according to an embodiment, the hole transport region HTR may include a compound represented by Formula H-1:
In Formula H-1, L1 and L2 may each independently be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms. In Formula H-1, a and b may each independently be an integer from 0 to 10. When a or b is 2 or greater, multiple L1 groups or multiple L2 groups may each independently be a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms.
In Formula H-1, Ar1 and Ar2 may each independently be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. In Formula H-1, Ar3 may be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.
In an embodiment, the compound represented by Formula H-1 may be a monoamine compound. In another embodiment, the compound represented by Formula H-1 may be a diamine compound in which at least one of Ar1 to Ar3 includes an amine group as a substituent.
In still another embodiment, the compound represented by Formula H-1 may be a carbazole-based compound in which at least one of Ar1 and Ar2 includes a substituted or unsubstituted carbazole group, or may be a fluorene-based compound in which at least one of Ar1 and Ar2 includes a substituted or unsubstituted fluorene group.
The compound represented by Formula H-1 may be any compound selected from Compound Group H. However, the compounds listed in Compound Group H are only examples, and a compound represented by Formula H-1 is not limited to Compound Group H:
The hole transport region HTR may include a phthalocyanine compound such as copper phthalocyanine, N1, N1′-([1,1′biphenyl]-4,4′-diyl)bis(N1-phenyl-N4,N4-di-m-tolylbenzene-1,4-diamine) (DNTPD), 4,4′,4″-[tris(3-methylphenyl)phenylamino]0 triphenylamine (m-MTDATA), 4,4′,4″-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4′,4″-tris[N(2-naphthyl)-N-phenylamino]-triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB), triphenylamine-containing polyetherketone (TPAPEK), 4-isopropyl-4′-methyldiphenyliodonium [tetrakis(pentafluorophenyl)borate], dipyrazino[2,3-f: 2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HATCN), etc.
The hole transport region HTR may include a carbazole-based derivative such as N-phenyl carbazole or polyvinyl carbazole, a fluorene-based derivative, a triphenylamine-based derivative such as N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine (TPD) or 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB), 4,4′-cyclohexylidene bis[N,N-bis(4-methylphenyl]benzenamine](TAPC), 4,4′-bis[N,N′-(3-tolyl)amino]-3,3′-dimethylbiphenyl (HMTPD), 1,3-bis(N-carbazolyl)benzene (mCP), etc.
The hole transport region HTR may include 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi), 9-phenyl-9H-3,9′-bicarbazole (CCP), 1,3-bis(1,8-dimethyl-9H-carbazol-9-yl)benzene (mDCP), etc.
The hole transport region HTR may include the above-described compounds of the hole transport region in at least one of a hole injection layer HIL, a hole transport layer HTL, and an electron blocking layer EBL.
A thickness of the hole transport region HTR may be in a range of about 100 Å to about 10,000 Å. For example, the thickness of the hole transport region HTR may be in a range of about 100 Å to about 5,000 Å. When the hole transport region HTR includes a hole injection layer HIL, the hole injection layer HIL may have a thickness in a range of about 30 Å to about 1,000 Å. When the hole transport region HTR includes a hole transport layer HTL, the hole transport layer HTL may have a thickness in a range of about 250 Å to about 1,000 Å. When the hole transport region HTR includes an electron blocking layer EBL, the electron blocking layer EBL may have a thickness in a range of about 10 Å to about 1,000 Å. If the thicknesses of the hole transport region HTR, the hole injection layer HIL, the hole transport layer HTL and the electron blocking layer EBL satisfy the above-described ranges, satisfactory hole transport properties may be achieved without a substantial increase in driving voltage.
The hole transport region HTR may further include a charge generating material to increase conductivity, in addition to the above-described materials. The charge generating material may be dispersed uniformly or non-uniformly in the hole transport region HTR. The charge generating material may be, for example, a p-dopant. The p-dopant may include at least one of a halogenated metal compound, a quinone derivative, a metal oxide, and a cyano group-containing compound, but embodiments are not limited thereto. For example, the p-dopant may include a metal halide compound such as CuI or RbI, a quinone derivative such as tetracyanoquinodimethane (TCNQ) or 2,3,5,6-tetrafluoro-7,7′8,8-tetracyanoquinodimethane (F4-TCNQ), a metal oxide such as tungsten oxide or molybdenum oxide, a cyano group-containing compound such as dipyrazino[2,3-f: 2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HATCN) or 4-[[2,3-bis[cyano-(4-cyano-2,3,5,6-tetrafluorophenyl)methylidene]cyclopropylidene]-cyanomethyl]-2,3,5,6-tetrafluorobenzonitrile (NDP9), etc., but embodiments are not limited thereto.
As described above, the hole transport region HTR may further include at least one of a buffer layer (not shown) and an electron blocking layer EBL, in addition to a hole injection layer HIL and a hole transport layer HTL. The buffer layer (not shown) may compensate for a resonance distance according to a wavelength of light emitted from the emission layer EML and may thus increase light emission efficiency. A material that may be included in the hole transport region HTR may be used as a material in the buffer layer (not shown). The electron blocking layer EBL may prevent the injection of electrons from an electron transport region ETR to a hole transport region HTR.
The emission layer EML may be provided on the hole transport region HTR. The emission layer EML may have a thickness in a range of about 100 Å to about 1,000 Å. For example, the emission layer EML may have a thickness in a range of about 100 Å to about 300 Å. The emission layer EML may be a layer consisting of a single material, a layer including different materials, or a structure including multiple layers including different materials.
The light emitting element ED according to an embodiment may include a fused polycyclic compound represented by Formula 1 in at least one functional layer disposed between the first electrode EL1 and the second electrode EL2. In the light emitting element ED, the emission layer EML may include a fused polycyclic compound according to an embodiment. In an embodiment, the emission layer EML may include the fused polycyclic compound as a dopant. The fused polycyclic compound may be a dopant material of the emission layer EML. In the specification, the fused polycyclic compound according to an embodiment may be referred to as a first compound.
The fused polycyclic compound may include a fused ring core in which five rings are fused and which contains a boron atom, a nitrogen atom, and a heteroatom, and a first substituent linked to the fused ring core. The fused ring core may include three substituted or unsubstituted benzene rings that are linked via a boron atom, a nitrogen atom, and a heteroatom, thereby forming five rings. In the three benzene rings that are included in the fused ring core, the three benzene rings may be linked around the first boron atom, and among the three benzene rings, a first benzene ring and a second benzene ring may be linked via the heteroatom, and a third benzene ring may be linked to the first benzene ring via the nitrogen atom. The boron atom, the nitrogen atom, and the heteroatom may all be linked to the first benzene ring. In an embodiment, the heteroatom may be an oxygen (O) atom, a sulfur (S) atom, or a nitrogen (N) atom.
The fused polycyclic compound may include a first substituent linked to the fused ring core. The first substituent may be linked to the nitrogen atom. The first substituent may include a fourth benzene ring, and may include a structure in which a first sub-substituent is linked at a defined position of the fourth benzene ring. For example, the first substituent may include a structure in which the fourth benzene ring linked to the nitrogen atom is linked to the first sub-substituent which is linked to a carbon atom at an ortho-position with respect to the carbon atom linked to the first nitrogen atom among the carbon atoms constituting the fourth benzene ring. In an embodiment, the first sub-substituent may be a substituted or unsubstituted alkyl group having at least four carbon atoms.
In an embodiment, the first substituent may include a first ring which is fused with or linked to the fourth benzene ring. The first ring may be fused so as to share at least two carbon atoms of the fourth benzene ring or covalently linked to a carbon atom of the fourth benzene ring. For example, referring to Formula Al, the first ring may be fused so as to share at least two carbon atoms among carbon atoms a1 to a4, or the first ring may be covalently linked to any one of carbon atoms a1 to a4. In an embodiment, the first ring may be a substituted or unsubstituted monocyclic heterocycle, a substituted or unsubstituted polycyclic heterocycle, a substituted or unsubstituted monocyclic hydrocarbon ring, or a substituted or unsubstituted polycyclic hydrocarbon ring. For example, the first ring may be a substituted or unsubstituted benzene ring, a substituted or unsubstituted benzofuran ring, or a substituted or unsubstituted benzothiophene ring. In an embodiment, the first substituent may include at least one first ring.
For example, a single first ring may be provided, or multiple first rings may be provided. In the specification, the first substituent may be a group represented by Formula 2, which will be described later.
In Formula A1, Q1 may correspond to the above-described first sub-substituent. In Formula A1, is a position linked to the nitrogen atom of the fused ring core.
The fused polycyclic compound according to an embodiment may be represented by Formula 1:
The fused polycyclic compound represented by Formula 1 may include a fused ring core in which five rings are fused around a boron atom, a nitrogen atom, and a heteroatom, and a first substituent that is linked to the fused ring core. In the specification, the benzene ring that includes R1 in Formula 1 may correspond to the aforementioned first benzene ring, the benzene ring that includes R2 may correspond to the aforementioned second benzene ring, and the benzene ring that includes R3 may correspond to the aforementioned third benzene ring. In the specification, Rx1 in Formula 1 may correspond to the aforementioned first substituent.
In Formula 1, R1 to R3 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, R1 to R3 may each independently be a substituted or unsubstituted t-butyl group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbazole group.
In Formula 1, a may be an integer from 0 to 3. If a is 0, the fused polycyclic compound may not be substituted with R1. A case where a is 3 and three R1 groups are all hydrogen atoms may be the same as a case where a is 0. If a is 2 or greater, multiple R1 groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 1, b and c may each independently be an integer from 0 to 4. If b and c are each 0, the fused polycyclic compound may not be substituted with R2 and R3, respectively. A case where b and c are each 4 and four R2 groups and four R3 groups are each hydrogen atoms may be the same as a case where b and c are each 0. If b and c are each 2 or greater, multiple groups of each of R2 and R3 may all be the same or at least one thereof may be different from the remainder.
In Formula 1, X may be O, S, or N(Rx2).
In Formula 1, Rx1 may be a group represented by Formula 2.
In Formula 1, Rx2 may be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, or a group represented by Formula 2.
In Formula 2, Re may be a hydrogen atom or a deuterium atom. For example, Re may be a hydrogen atom.
In Formula 2, R4 may be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. In an embodiment, R4 may be a substituted or unsubstituted linear alkyl group having 1 to 20 carbon atoms. In an embodiment, R4 may be a substituted or unsubstituted linear alkyl group having 1 to 10 carbon atoms. For example, R4 may be a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, or a substituted or unsubstituted n-propyl group.
In Formula 2, ring A to ring H may each independently be a substituted or unsubstituted five-membered heterocycle, a substituted or unsubstituted six-membered heterocycle, or a substituted or unsubstituted six-membered aromatic hydrocarbon ring. In an embodiment, ring A to ring H may each independently be a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, or a substituted or unsubstituted benzene ring.
In Formula 2, a dashed line may represent a bonding line. For example, in Formula 2, when at least one of ring E, ring F, ring G, and ring H is present and ring A to ring D are not present, the dashed line between the benzene ring that includes Rz in Formula 2 and ring E, ring F, ring G, or ring H may be a bonding line.
In Formula 2, ring A to ring H may each independently be present or absent. For example, in Formula 2, ring E may be present, and the remainder, which are ring A to ring D and ring F to ring H, may be absent. Thus, in Formula 2, the dashed line between the benzene ring that includes Rz and ring E may represent a bonding line. As another example, in Formula 2, ring F may be present, and the remainder, which are ring A to ring E, ring G, and ring H, may be absent. Thus, in Formula 2, the dashed line between the benzene ring that includes Rz and ring F may represent a bonding line. As another example, in Formula 2, ring G may be present, and the remainder, which are ring A to ring F and ring H, may be absent. Thus, in Formula 2, the dashed line between the benzene ring that includes Rz and ring G may represent a bonding line. As another example, in Formula 2, ring E and ring G may be present, and the remainder, which are ring A to ring D, ring F, and ring H may be absent. Thus, in Formula 2, the dashed line between the benzene ring that includes Rz and ring E and the dashed line between the benzene ring that includes Rz and ring G may each represent a bonding line. As another example, in Formula 2, ring A and ring E may be present, and the remainder, which are ring B to ring D and ring F to ring H, may be absent. As another example, in Formula 2, ring B and ring F may be present, and the remainder, which are ring A, ring C to ring E, ring G, and ring H, may be absent. As another example, in Formula 2, ring C and ring G may be present, and the remainder, which are ring A, ring B, ring D to ring F, and ring H, may be absent. As another example, in Formula 2, ring C and ring F may be present, and the remainder, which are ring A, ring B, ring D, ring E, ring G, and ring H, may be absent. As another example, in Formula 2, ring B and ring E may be present, and the remainder, which are ring A, ring C, ring D, and ring F to ring H, may be absent. As another example, in Formula 2, ring A and ring H may be present, and the remainder, which are ring B to ring G, may be absent.
In Formula 2, Rz may be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, Rz may be a hydrogen atom, a substituted or unsubstituted n-butyl group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted n-pentyl group, a substituted or unsubstituted n-hexyl group, or a substituted or unsubstituted phenyl group.
In Formula 2, d may be an integer from 0 to 4. If d is 0, the fused polycyclic compound may not be substituted with Rz. A case where d is 4 and four Rz groups are all hydrogen atoms may be the same as a case where d is 0. If a is 2 or greater, multiple Rz groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 2, is a position linked to Formula 1.
In Formula 2, when each of ring A to ring H are absent, the group represented by Formula 2 may include an Rz group in place of a hydrogen atom at an ortho position with respect to . For example, the group represented by Formula 2 may have a structure in which a substituted or unsubstituted alkyl group having at least four carbon atoms is a substituent at two ortho positions with respect to
. For example, in Formula 2, when each of ring A to ring H are absent, the group represented by Formula 2 may be represented by Formula 2-a:
In Formula 2-a, Rza may be a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. In an embodiment, Rza may be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.
In the fused polycyclic compound, the first substituent may further include a second sub-substituent. The second sub-substituent may be linked to a carbon atom at an ortho position with respect to the carbon atom linked to the first nitrogen atom, among the carbon atoms constituting the fourth benzene ring. For example, the first sub-substituent may be linked at an ortho-position carbon atom with respect to the nitrogen atom in the fourth benzene ring of the first substituent, and the second sub-substituent may be linked to the other ortho-position carbon atom. In an embodiment, the second sub-substituent may be a substituted or unsubstituted alkyl group having at least four carbon atoms.
In an embodiment, Rza may be a substituted or unsubstituted linear alkyl group having 1 to 10 carbon atoms. For example, Rza may be a substituted or unsubstituted n-butyl group, a substituted or unsubstituted n-phenyl group, or a substituted or unsubstituted n-hexyl group.
In Formula 2-a, Rzb may be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.
In Formula 2-a, dx may be an integer from 0 to 3. If dx is 0, the fused polycyclic compound may not be substituted with Rzb. A case where dx is 3 and three Rzb groups are all hydrogen atoms may be the same as a case where dx is 0. If dx is 2 or greater, multiple Rzb groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 2-a, Re and R4 are the same as described in Formula 2.
In an embodiment, the group represented by Formula 2 may be a group represented by any one of Formula 2-b-1 to Formula 2-b-10:
Formula 2-b-1 to Formula 2-b-10 represent embodiments where the inclusion or absence of each of ring A to ring H in Formula 2 is further defined. Formula 2-b-1 represents a case where in Formula 2, ring E is present, and the remaining ring A to ring D and ring F to ring H are absent. Formula 2-b-2 represents a case where in Formula 2, ring F is present, and the remaining ring A to ring E, ring G, and ring H are absent. Formula 2-b-3 represents a case where in Formula 2, ring G is present, and the remaining ring A to ring F and ring H are absent. Formula 2-b-4 represents a case where in Formula 2, ring E and ring G are present, and the remaining ring A to ring D, ring F, and ring H are absent. Formula 2-b-5 represents a case where in Formula 2, ring A and ring E are present, and the remaining ring B to ring D and ring F to ring H are absent. Formula 2-b-6 represents a case where in Formula 2, ring B and ring F are present, and the remaining ring A, ring C to ring E, ring G, and ring H are absent. Formula 2-b-7 represents a case where in Formula 2, ring C and ring G are present, and the remaining ring A, ring B, ring D to ring F, and ring H are absent. Formula 2-b-8 represents a case where in Formula 2, ring C and ring F are present, and the remaining ring A, ring B, ring D, ring E, ring G, and ring H are absent. Formula 2-b-9 represents a case where in Formula 2, ring B and ring E are present, and the remaining ring A, ring C, ring D, and ring F to ring H are absent. Formula 2-b-10 represents a case where in Formula 2, ring A and ring H are present, and the remaining ring B to ring G are absent.
In Formula 2-b-1 to Formula 2-b-10, Re, R4, Rz, d, ring A to ring C, and ring E to ring H are the same as described in Formula 2.
In an embodiment, the group represented by Formula 2 may be a group represented by any one of Formula 2-1 to Formula 2-18:
In Formula 2-5 and Formula 2-6, Rf and Rg may each independently be a hydrogen atom or a deuterium atom. For example, Rf and Rg may each be a hydrogen atom.
In Formula 2-5 and Formula 2-6, R5 and R6 may each independently be a substituted or unsubstituted alkyl group are the 1 to 20 carbon atoms. In an embodiment, R5 and R6 may each independently be a substituted or unsubstituted linear alkyl group having 1 to 10 carbon atoms. For example, R5 and R6 may each independently be a substituted or unsubstituted n-butyl group, a substituted or unsubstituted n-pentyl group, or a substituted or unsubstituted n-hexyl group.
In Formula 2-1 to Formula 2-18, Rz1 to Rz18 and Ra1 to Ra17 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, Rz1 to Rz18 may each independently be a hydrogen atom, a substituted or unsubstituted n-butyl group, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group, and Ra1 to Ra17 may each be a hydrogen atom.
In Formula 2-1 to Formula 2-18, d1 to d3 and d5 may each independently be an integer from 0 to 3; d4 and d6 to d18 may each independently be an integer from 0 to 2; m1 to m5 may each independently be an integer from 0 to 5; and m6 to m17 may each independently be an integer from 0 to 4.
If d1 to d3 and d5 are each 0, the fused polycyclic compound may not be substituted with Rz1 to Rz3 and Rz5, respectively. A case where d1 to d3 and d5 are each 3 and three groups of each of Rz1 to Rz3, and Rz5 are all hydrogen atoms may be the same as a case where d1 to d3 and d5 are each 0. If d1 to d3 and d5 are each 2 or greater, multiple groups of each of Rz1 to Rz3 and Rz5 may all be the same or at least one thereof may be different from the remainder.
If d4 and d6 to d18 are each 0, the fused polycyclic compound may not be substituted with Rz4 and Rz6 to Rz18, respectively. A case where d4 and d6 to d18 are each 2 and two groups of each of Rz4 and Rz6 to Rz18 are all hydrogen atoms may be the same as a case where d4 and d6 to d18 are each 0. If d4 and d6 to d18 are each 2 or greater, multiple groups of each of Rz4 and Rz6 to Rz18 may all be the same or at least one thereof may be different from the remainder.
If m1 to m5 are each 0, the fused polycyclic compound may not be substituted with Ra1 to Ra5, respectively. A case where m1 to m5 are each 5 and five groups of each of Ra1 to Ra5 are all hydrogen atoms may be the same as case a where m1 to m5 are each 0. If m1 to m5 are each 2 or greater, multiple groups of each of Ra1 and Ra5 may all be the same or at least one thereof may be different from the remainder.
If m6 to m17 are each 0, the fused polycyclic compound may not be substituted with Ra6 to Ra17, respectively. A case where m6 to m17 are each 4 and four groups of each of Ra6 to Ra17 are all hydrogen atoms may be the same as a case where m6 to m17 are each 0. If m6 to m17 are each 2 or greater, multiple groups of each of Ra6 and Ra17 may all be the same or at least one thereof may be different from the remainder.
In Formula 2-1 to Formula 2-18, is a position linked to Formula 1.
In Formula 2-1 to Formula 2-18, Re and R4 are the same as described in Formula 2.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 3-1 or Formula 3-2:
In Formula 3-1, X1 may be O or S.
In Formula 3-2, X2 may be N(Rx2′).
In Formula 3-2, Rx2′ may be a group represented by Formula 4-1 or Formula 4-2:
In Formula 4-2, Rh may be a hydrogen atom or a deuterium atom. For example, Rh may be a hydrogen atom.
In Formula 4-1 and Formula 4-2, Rb1 to Rb3 and Ry may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, Rb1 to Rb3 may each independently be a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group; and Ry may be a hydrogen atom, a substituted or unsubstituted n-butyl group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted n-pentyl group, a substituted or unsubstituted n-hexyl group, or a substituted or unsubstituted phenyl group.
In Formula 4-1, n1 and n3 may each independently be an integer from 0 to 5. If n1 and n3 are each 0, the fused polycyclic compound may not be substituted with Rb1 and Rb3, respectively. A case where n1 and n3 are each 5 and five Rb1 groups and five Rb3 groups are all hydrogen atoms may be the same as a case where n1 and n3 are each 0. If n1 and n3 are each 2 or greater, multiple groups of each of Rb1 and Rb3 may all be the same or at least one thereof may be different from the remainder.
In Formula 4-1, n2 may be an integer from 0 to 3. If n2 is 0, the fused polycyclic compound may not be substituted with Rb2. A case where n2 is 3 and three Rb2 groups are all hydrogen atoms may be the same as a case where n2 is 0. If n2 is 2 or greater, multiple Rb2 groups may be all the same or at least one thereof may be different from the remainder.
In Formula 4-2, ring I to ring P may each independently be a substituted or unsubstituted five-membered heterocycle, a substituted or unsubstituted six-membered heterocycle, or a substituted or unsubstituted six-membered aromatic hydrocarbon ring. In an embodiment, ring I to ring P may be each independently a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, or a substituted or unsubstituted benzene ring.
In Formula 4-2, a dashed line may represent a bonding line. For example, in Formula 4-2, when at least one of ring M, ring N, ring O, and ring P is present and ring I to ring L are not present, the dashed line between the benzene ring that includes Ry in Formula 4-2 and ring M, ring N, ring O, or ring P may be a bonding line.
In Formula 4-2, ring I to ring P may each independently be present or absent. For example, in Formula 4-2, ring M may be present, and the remainder, which are ring I to ring L and ring N to ring P, may be absent. Thus, in Formula 4-2, the dashed line between the benzene ring that includes Ry and ring M may represent a bonding line. As another example, in Formula 4-2, ring N may be present, and the remainder, which are ring I to ring M, ring O, and ring P, may be absent. Thus, in Formula 4-2, the dashed line between the benzene ring that includes Ry and ring N may represent a bonding line. As another example, in Formula 4-2, ring O may be present, and the remainder, which are ring I to ring N, and ring P, may be absent. Thus, in Formula 4-2, the dashed line between the benzene ring that includes Ry and ring O may represent a bonding line. As another example, in Formula 4-2, ring M and ring O may be present, and the remainder, which are ring I to ring L, ring N, and ring P, may be absent. Thus, in Formula 4-2, the dashed line between the benzene ring that includes Ry and ring M and ring O may represent a bonding line. As another example, in Formula 4-2, ring I and ring M may be present, and the remainder, which are ring J to ring L and ring N to ring P, may be absent. As another example, in Formula 4-2, ring J and ring N may be present, and the remainder, which are ring I, ring K to ring M, ring O, and ring P, may be absent. As another example, in Formula 4-2, ring K and ring O may be present, and the remainder, which are ring I, ring J, ring L to ring N, and ring P, may be absent. As another example, in Formula 4-2, ring K and ring N may be present, and the remainder, which are ring I, ring J, ring L, ring M, ring O, and ring P, may be absent. As another example, in Formula 4-2, ring J and ring M may be present, and the remainder, which are ring I, ring K, ring L, and ring N to ring P, may be absent. As another example, in Formula 4-2, ring I and ring P may be present, and the remainder, which are ring J to ring O, may be absent.
In Formula 4-2, R7 may be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. In an embodiment, R7 may be a substituted or unsubstituted linear alkyl group having 1 to 20 carbon atoms. In an embodiment, R7 may be a substituted or unsubstituted linear alkyl group having 1 to 10 carbon atoms. For example, R7 may be a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, or a substituted or unsubstituted n-propyl group.
In Formula 4-2, e may be an integer from 0 to 4. If e is 0, the fused polycyclic compound may not be substituted with Ry. A case where e is 4 and four Ry groups are all hydrogen atoms may be the same as a case where e is 0. If e is 2 or greater, multiple Ry groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 4-1 and Formula 4-2, is a position linked to Formula 3-2.
In Formula 3-1 and Formula 3-2, R1 to R3, a to c, and Rx1 are the same as described in Formula 1.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 5-1 or Formula 5-2:
In Formula 5-1 and Formula 5-2, R3′ may be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, R3′ may be a hydrogen atom.
In Formula 5-1 and Formula 5-2, c′ may be an integer from 0 to 3. If c′ is 0, the fused polycyclic compound may not be substituted with R3′. A case where c′ is 3 and three R3′ groups are all hydrogen atoms may be the same as a case where c′ is 0. If c′ is 2 or greater, multiple R3′ groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 5-1 and Formula 5-2, R3a and R3b may each independently be a group represented by Formula A-1 or Formula A-2:
In Formula A-1 and Formula A-2, Rc1 to Rc3 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, Rc1 to Rc3 may each independently be a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.
In Formula A-1, n11 may be an integer from 0 to 5. If n11 is 0, the fused polycyclic compound may not be substituted with Rc1. A case where n11 is 5 and five Rc1 groups are all hydrogen atoms may be the same as a case where n11 is 0. If n11 is 2 or greater, multiple Rc1 groups may be all the same or at least one thereof may be different from the remainder.
In Formula A-2, n12 and n13 may each independently be an integer from 0 to 4. If n12 and n13 are each 0, the fused polycyclic compound may not be substituted with Rc2 and Rc3, respectively. A case where n12 and n13 are each 4 and four Rc2 groups and four Rc3 groups are all hydrogen atoms may be the same as a case where n12 and n13 are each 0. If n12 and n13 are each 2 or greater, multiple groups of each of Rc2 and Rc3 may all be the same or at least one thereof may be different from the remainder.
In Formula 5-1 and Formula 5-2, R1, R2, a, b, X, and Rx1 are the same as described in Formula 1.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by any one of Formula 6-1 to Formula 6-4:
In Formula 6-1 to Formula 6-4, R2′, R3′, and Rd1 to Rd12 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, R2′ and R3′ may each be a hydrogen atom, and Rd1 to Rd12 may each independently be a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.
In Formula 6-1 to Formula 6-4, b′ and c′ may each independently be an integer from 0 to 3. If b′ and c′ are each 0, the fused polycyclic compound may not be substituted with R2′ and R3′, respectively. A case where b′ and c′ are each 3 and three R2′ groups and three R3′ groups are all hydrogen atoms may be the same as a case where b′ and c′ are each 0. If b′ and c′ are each 2 or greater, multiple groups of each of R2′ and R3′ may all be the same or at least one thereof may be different from the remainder.
In Formula 6-1 to Formula 6-4, n21 to n23 and n28 may each independently be an integer from 0 to 5; and n24 to n27 and n29 to n32 may each independently be an integer from 0 to 4. If n21 to n32 are each 0, the fused polycyclic compound may not be substituted with Rd1 to Rd12, respectively. A case where n21 to n23 and n28 are each 5 and five groups of each of Rd1 to Rd3 and Rd8 are all hydrogen atoms may be the same as a case where n21 to n23 and n28 are each 0. A case where n24 to n27 and n29 to n32 are each 4 and four groups of each of Rd4 to Rd7 and Rd9 to Rd12 are all hydrogen atoms may be the same as a case where n24 to n27 and n29 to n32 are each 0. When n21 to n32 are each 2 or greater, multiple groups of each of Rd1 to Rd12 may all be the same or at least one thereof may be different from the remainder.
In Formula 6-1 to Formula 6-4, X, R1, a, and Rx1 are the same as described in Formula 1.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 7:
In Formula 7, R1′ may be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, R1′ may be a hydrogen atom.
In Formula 7, a′ may be an integer from 0 to 2. If a′ is 0, the fused polycyclic compound may not be substituted with R1′. A case where a′ is 2 and two R1′ groups are all hydrogen atoms may be the same as a case where a′ is 0. If a′ is 2, two R1′ groups may all be the same, or one thereof may be different from the remainder.
In Formula 7, R1a may be a substituted or unsubstituted alkyl group having 1 to 10 atoms or a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms.
For example, R1a may be a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.
In Formula 7, R2, R3, b, c, X, and Rx1 are the same as described in Formula 1.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 8-1 or Formula 8-2:
In Formula 8-1, Re′ may be a hydrogen atom or a deuterium atom. For example, Re′ may be a hydrogen atom.
In Formula 8-1, R4′ may be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. In an embodiment, R4′ may be a substituted or unsubstituted linear alkyl group having 1 to 20 carbon atoms. In an embodiment, R4′ may be a substituted or unsubstituted linear alkyl group having 1 to 10 carbon atoms. For example, R4′ may be a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, or a substituted or unsubstituted n-propyl group.
In Formula 8-1, Rz′ may be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, Rz′ may be a hydrogen atom, a substituted or unsubstituted n-butyl group, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.
In Formula 8-1, d′ may be an integer from 0 to 3. If d′ is 0, the fused polycyclic compound may not be substituted with Rz′. A case where d′ is 3 and three Rz′ groups are all hydrogen atoms may be the same as a case where d′ is 0. If d′ is 2 or greater, multiple Rz′ groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 8-2, Rx1′ may be a group represented by Formula 9:
In Formula 9, Rz″ may be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, Rz″ may be a hydrogen atom, a substituted or unsubstituted n-butyl group, a substituted or unsubstituted n-pentyl group, a substituted or unsubstituted n-hexyl group, or a substituted or unsubstituted phenyl group.
In Formula 9, d″ may be an integer from 0 to 3. If d″ is 0, the fused polycyclic compound may not be substituted with Rz′. A case where d″ is 3 and three Rz′ groups are all hydrogen atoms may be the same as a case where d″ is 0. If d″ is 2 or greater, multiple Rz″ groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 9, ring A′ to ring H′ may each independently be a substituted or unsubstituted furan ring, a substituted or unsubstituted thiophene ring, or a substituted or unsubstituted benzene ring.
In Formula 9, at least one of ring A′ to ring H′ may each be present, and the remainder of ring A′ to ring H′ may each be absent. For example, the group represented by Formula 9 may include at least one of ring A′ to ring H′.
In Formula 9, is a position linked to Formula 8-2.
In Formula 9, R4 and Re are the same as described in Formula 2.
In Formula 8-1 and Formula 8-2, X, Re, R1 to R4, and a to c are the same as described in Formula 1 and Formula 2.
In an embodiment, the fused polycyclic compound represented by Formula 1 may include at least one deuterium atom as a substituent. Thus, in the fused polycyclic compound represented by Formula 1, at least one hydrogen atom may be substituted with a deuterium atom.
In an embodiment, the fused polycyclic compound may be any compound selected from Compound Group 1. In an embodiment, in the light emitting element ED, the at least one functional layer (for example, an emission layer EML) may include at least one fused polycyclic compound selected from Compound Group 1:
In Compound Group 1, D represents a deuterium atom.
The fused polycyclic compound may contribute to a long service life through a structure in which the first substituent is linked to the fused ring core.
The fused polycyclic compound includes a fused ring core in which five rings are fused and which contains a boron atom, a nitrogen atom, and a heteroatom, and the first substituent linked to the nitrogen atom of the fused ring core. In an embodiment, in the fused ring core of the fused polycyclic compound, the first to third benzene rings are linked via the boron atom, the nitrogen atom, and the heteroatom, thereby forming five rings. The first substituent may include a fourth benzene ring, and may have a structure in which a first sub-substituent is linked at a position of the fourth benzene ring. The first substituent may have a structure in which the fourth benzene ring that is linked to the nitrogen atom of the fused ring core is itself linked to the first sub-substituent at a carbon atom at an ortho-position with respect to the nitrogen atom.
The fused polycyclic compound according to an embodiment may exhibit excellent molecular stability due to the inclusion of the first substituent, and thus may contribute to a long service life of the light emitting element ED. The first substituent may have a structure in which the first sub-substituent corresponding to a substituted or unsubstituted alkyl group is substituted at an ortho position with respect to the nitrogen atom. It may be possible to effectively achieve an intermolecular distance by the inclusion of an alkyl group, as a first sub-substituent, which has a longer molecular field compared to a phenyl group at an ortho position with respect to the nitrogen atom. Since a highest occupied molecular orbital (HOMO) and a lowest unoccupied molecular orbital (LUMO) are not diffused in the alkyl group, it is difficult for the alkyl group to become a reaction point where molecules may react with each other.
Therefore, HOMO and LUMO energy distribution may be suppressed by the alkyl group of the first substituent, thereby preventing unnecessary interaction with other molecules. In contrast to a phenyl substituent, the alkyl group does not cause distortion in the molecule, and the alkyl group extends in a direction away from the boron atom on the basis of a plane including the fused ring core, and thus it may be more effective to achieve an effective intermolecular distance. For example, in the fused polycyclic compound, HOMO and LUMO energy distribution may be suppressed in the alkyl group of the first substituent to prevent unnecessary interaction with other molecules, and a reaction point of the fused ring core may be effectively protected due to steric hindrance. Accordingly, the fused polycyclic compound has a structure having a high electron density in the fused ring core and through the first substituent, a reaction point of the fused ring core may be effectively protected, so that the molecular stability of the compound may be improved.
The fused polycyclic compound according to an embodiment may effectively maintain a trigonal planar structure of the boron atom through a steric hindrance effect by the first substituent. The boron atom may have electron deficiency characteristics due to a vacant p-orbital, which may be susceptible to forming a bond with other nucleophiles, and may thus be changed into a tetrahedral structure, which may cause deterioration of the element.
According to embodiments, the fused polycyclic compound represented by Formula 1 includes the first substituent having a structure that provides steric hindrance, thereby effectively protecting the vacant p-orbital of the boron atom, and thus may prevent deterioration due to a structural change to a tetrahedral configuration.
The fused polycyclic compound may contribute to increased luminous efficiency because intermolecular interactions may be suppressed by the inclusion of the first substituent, thereby controlling the formation of excimers or exciplexes. Since the fused polycyclic compound represented by Formula 1 includes the first substituent, intermolecular distance is increased and thus Dexter energy transfer may be reduced. Dexter energy transfer is a phenomenon in which a triplet exciton moves between molecules, and increases when intermolecular distance is short, and may contribute to increased quenching phenomenon due to an increase in triplet concentration. The fused polycyclic compound according to an embodiment has increased intermolecular distance due to a large steric hindrance effect to thereby suppress Dexter energy transfer, and thus may suppress the deterioration of service life due to an increase of triplet concentration. Therefore, when the fused polycyclic compound is applied to an emission layer EML of the light emitting element ED, luminous efficiency may be increased and the element service life may be improved.
A full width at half maximum (FWHM) of an emission spectrum of the fused polycyclic compound may be in a range of about 10 nm to about 50 nm. For example, FWHM of an emission spectrum of the fused polycyclic compound may be in a range about 20 nm to about 40 nm. Since an FWHM of an emission spectrum of the fused polycyclic compound is within the range described above, when the fused polycyclic compound is included as a material in a light emitting element, luminous efficiency may be improved. When the fused polycyclic compound is included as a material of a blue light emitting element, element service life may be improved.
In an embodiment, the fused polycyclic compound according to an embodiment may be a thermally activated delayed fluorescence emitting material. In an embodiment, the fused polycyclic compound may be a thermally activated delayed fluorescence dopant having a difference (ΔEST) between a lowest triplet exciton energy level (T1) and a lowest singlet exciton energy level (S1) equal to or less than about 0.6 eV. For example, the fused polycyclic compound may be a thermally activated delayed fluorescence dopant having a difference (ΔEST) between a lowest triplet exciton energy level (T1) and a lowest singlet exciton energy level (S1) equal to or less than about 0.2 eV. However, embodiments are not limited thereto.
In an embodiment, the fused polycyclic compound may include the first substituent as described above. By adjusting the quantity and bonding positions of substituents and sub-substituents for the first substituent, a singlet energy level and a triplet energy level may be appropriately adjusted in the overall fused polycyclic compound. Accordingly, the fused polycyclic compound according to an embodiment may exhibit improved thermally activated delayed fluorescence characteristics.
The fused polycyclic compound may be a luminescent material having a central wavelength in a range of about 430 nm to about 490 nm. For example, the fused polycyclic compound may be a blue thermally activated delayed fluorescence (TADF) dopant. However, embodiments are not limited thereto, and when the fused polycyclic compound is used as a luminescent material, the fused polycyclic compound may be used as a dopant material that emits light in various wavelength regions, such as a red emitting dopant or a green emitting dopant.
In the light emitting element ED, the emission layer EML may emit delayed fluorescence. For example, the emission layer EML may emit thermally activated delayed fluorescence (TADF).
The emission layer EML of the light emitting element ED may emit blue light. For example, the emission layer EML of the light emitting element ED may emit blue light having a central wavelength equal to or less than about 490 nm. However, embodiments are not limited thereto, and the emission layer EML may emit green light or red light.
The fused polycyclic compound may be included in an emission layer EML. The fused polycyclic compound may be included as a dopant material in an emission layer EML.
The fused polycyclic compound may be a thermally activated delayed fluorescence material.
The fused polycyclic compound may be used as a thermally activated delayed fluorescence dopant. For example, in the light emitting element ED, the emission layer EML may include, as a thermally activated delayed fluorescence dopant, at least one fused polycyclic compound selected from Compound Group 1 as described above. However, the use of the fused polycyclic compound is not limited thereto.
In an embodiment, the emission layer EML may include multiple compounds. In an embodiment, the emission layer EML may include the fused polycyclic compound represented by Formula 1 as a first compound, and at least one of a second compound represented by Formula HT-1, a third compound represented by Formula ET-1, and a fourth compound represented by Formula D-1.
In an embodiment, the emission layer EML may include the first compound represented by Formula 1, and may further include at least one of a second compound represented by Formula HT-1 and a third compound represented by Formula ET-1.
In an embodiment, the emission layer EML may further include a second compound represented by Formula HT-1. In an embodiment, the second compound may be used as a hole transport host material in the emission layer EML.
In Formula HT-1, M1 to M8 may each independently be N or C(R51). For example, M1 to M8 may each independently be C(R51). As another example, any one of M1 to M8 may be N, and the remainder of M1 to M8 may each independently be C(R51).
In Formula HT-1, L1 may be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms. For example, L1 may be a direct linkage, a substituted or unsubstituted phenylene group, a substituted or unsubstituted divalent biphenyl group, a substituted or unsubstituted divalent carbazole group, or the like, but embodiments are not limited thereto.
In Formula HT-1, Ya may be a direct linkage, C(R52)(R53), or Si(R54)(R55). For example, the two benzene rings that are connected to the nitrogen atom of Formula HT-1 may be connected to each other via a direct linkage,
In Formula HT-1, if Ya is a direct linkage, the second compound represented by Formula HT-1 may include a carbazole moiety.
In Formula HT-1, Ara may be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, Ara may be a substituted or unsubstituted carbazole group, a substituted or unsubstituted dibenzofuran group, a substituted or unsubstituted dibenzothiophene group, a substituted or unsubstituted biphenyl group, or the like, but embodiments are not limited thereto.
In Formula HT-1, R51 to R55 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms, or bonded to an adjacent group to form a ring. For example, R51 to R55 may each independently be a hydrogen atom or a deuterium atom. For example, R51 to R55 may each independently be an unsubstituted methyl group or an unsubstituted phenyl group.
In an embodiment, the second compound represented by Formula HT-1 may be selected from Compound Group 2. In an embodiment, in the light emitting element ED, the second compound may include at least one compound selected from Compound Group 2:
In Compound Group 2, D represents a deuterium atom, and Ph represents a substituted or unsubstituted phenyl group. For example, in Compound Group 2, Ph may represent an unsubstituted phenyl group.
In an embodiment, the emission layer EML may further include a third compound represented by Formula ET-1. In an embodiment, the third compound may be used as an electron transport host material in the emission layer EML.
In Formula ET-1, at least one of Za to Zc may each be N, and the remainder of Za to Zc may each independently be C(R56). For example, one of Za to Zc may be N, and the remainder of Za to Zc may each independently be C(R56). Thus, the third compound represented by Formula ET-1 may include a pyridine moiety. As another example, two of Za to Zc may each be N, and the remainder may be C(R56). Thus, the third compound represented by Formula ET-1 may include a pyrimidine moiety. As yet another example, Za to Zc may each be N. Thus, the third compound represented by Formula ET-1 may include a triazine moiety.
In Formula ET-1, R56 may be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms.
In Formula ET-1, b1 to b3 may each independently be an integer from 0 to 10.
In Formula ET-1, Arb to Ard may each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, Arb to Ard may each independently be a substituted or unsubstituted phenyl group or a substituted or unsubstituted carbazole group.
In Formula ET-1, L2 to L4 may each independently be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms. If b1 to b3 are each 2 or more, multiple groups of each of L2 to L4 may each independently be a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms.
In an embodiment, the third compound represented by Formula ET-1 may be selected from Compound Group 3. In an embodiment, in the light emitting element ED, the third compound may include at least one compound selected from Compound Group 3:
In Compound Group 3, D represents a deuterium atom, and Ph represents an unsubstituted phenyl group.
In an embodiment, the emission layer EML may include the second compound and the third compound, and the second compound and the third compound may form an exciplex. In the emission layer EML, an exciplex may be formed by a hole transport host and an electron transport host. A triplet energy level of the exciplex formed by a hole transport host and an electron transport host may correspond to a difference between a lowest unoccupied molecular orbital (LUMO) energy level of the electron transport host and a highest occupied molecular orbital (HOMO) energy level of the hole transport host.
For example, an absolute value of a triplet energy level (T1) of the exciplex formed by the hole transport host and the electron transport host may be in a range of about 2.4 eV to about 3.0 eV. The triplet energy level of the exciplex may have a value that is smaller than an energy gap of each host material. The exciplex may have a triplet energy level equal to or less than about 3.0 eV, which is an energy gap between the hole transport host and the electron transport host.
In an embodiment, the emission layer EML may include a fourth compound, in addition to the first compound, the second compound, and the third compound. The fourth compound may be used as a phosphorescence sensitizer in an emission layer EML. Energy may be transferred from the fourth compound to the first compound, thereby effecting light emission.
The emission layer EML may include, as a fourth compound, an organometallic complex that includes platinum (Pt) as a central metal atom and ligands bonded to the central metal atom. In an embodiment, the emission layer EML may further include a fourth compound represented by Formula D-1:
In Formula D-1, Q1 to Q4 may each independently be C or N.
In Formula D-1, C1 to C4 may each independently be a substituted or unsubstituted hydrocarbon ring having 5 to 30 ring-forming carbon atoms or a substituted or unsubstituted heterocycle having 2 to 30 ring-forming carbon atoms.
In Formula D-1, L11 to L13 may each independently be a direct linkage, ,
a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms. In L11 to L13, represents a bond to one of C1 to C4.
In Formula D-1, b11 to b13 may each independently be 0 or 1. If b11 is 0, C1 and C2 may not be directly connected to each other. If b12 is 0, C2 and C3 may not be directly connected to each other. If b3 is 0, C3 and C4 may not be directly connected to each other.
In Formula D-1, R61 to R66 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms, or bonded to an adjacent group to form a ring. For example, R61 to R66 may each independently be a substituted or unsubstituted methyl group or a substituted or unsubstituted t-butyl group.
In Formula D-1, e1 to e4 may each independently be an integer from 0 to 4. If e1 to e4 are each 0, the fourth compound may not be substituted with R61 to R64, respectively. A case where e1 to e4 are each 4, and four groups of each of R61 to R64 are all hydrogen atoms may be the same as a case where e1 to e4 are each 0. If e1 to e4 are each 2 or more, multiple groups of each of R61 to R64 may all be the same, or at least one thereof may be different from the remainder.
In an embodiment, in Formula D-1, C1 to C4 may each independently be a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle that is represented by any one of Formula C-1 to Formula C-4:
In Formula C-1 to Formula C-4, P1 may be or C(R74), P2 may be
or N(R81), P3 may be
or N(R82), and P4 may be
or C(R88).
In Formula C-1 to Formula C-4, R71 to R88 may each independently be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, or bonded to an adjacent group to form a ring.
In Formula C-1 to Formula C-4, represents a bond to Pt, and
represents a bond to an adjacent ring group (C1 to C4) or to a linking moiety (L11 to L13).
In an embodiment, the emission layer EML may include the first compound represented by Formula 1, and at least one of the second compound, the third compound, and the fourth compound. In an embodiment, the emission layer EML may include the first compound, the second compound, and the third compound. In the emission layer EML, the second compound and the third compound may form an exciplex, and energy may be transferred from the exciplex to the first compound, thereby effecting light emission.
In another embodiment, the emission layer EML may include the first compound, the second compound, the third compound, and the fourth compound. In the emission layer EML, the second compound and the third compound may form an exciplex, and energy may be transferred from the exciplex to the fourth compound and the first compound, thereby effecting light emission. In an embodiment, the fourth compound may be a sensitizer. In the light emitting element ED, the fourth compound included in the emission layer EML may serve as a sensitizer that transfers energy from a host (for example, an exciplex host) to the first compound, which is a light-emitting dopant. For example, the fourth compound, which serves as an auxiliary dopant, may accelerate energy transfer to the first compound, which serves as a light emitting dopant, thereby increasing an emission ratio of the first compound. Accordingly, efficiency of the emission layer EML may be improved. If energy transfer to the first compound increases, excitons formed in the emission layer EML may not accumulate and may rapidly emit light, so that deterioration of the light emitting element ED may be reduced. Accordingly, the lifetime of the light emitting element ED may increase.
The light emitting element ED may include the first compound, the second compound, the third compound, and the fourth compound, and the emission layer EML may include the combination of two host materials and two dopant materials. In the light emitting element ED, the emission layer EML may include the second compound and the third compound, which are two different hosts, the first compound which emits delayed fluorescence, and the fourth compound which includes an organometallic complex, and thus the light emitting element ED may exhibit excellent emission efficiency properties.
In an embodiment, the fourth compound represented by Formula D-1 may be selected from Compound Group 4. In an embodiment, in the light emitting element ED, the fourth compound may include at least one compound selected from Compound Group 4:
In Compound Group 4, D represents a deuterium atom.
In an embodiment, the light emitting element ED may include multiple emission layers. Multiple emission layers may be provided as a stack, so that a light emitting element ED including multiple emission layers may emit white light. The light emitting element ED including multiple emission layers may be a light emitting element having a tandem structure. If the light emitting element ED includes multiple emission layers, at least one emission layer EML may include the first compound represented by Formula 1. For example, if the light emitting element ED includes multiple emission layers, at least one emission layer EML may include the first compound, the second compound, the third compound, and the fourth compound.
In the light emitting element ED, if the emission layer EML includes the first compound, the second compound, the third compound, and the fourth compound, an amount of the first compound may be in a range of about 0.1 wt % to about 5 wt %, based on a total weight of the first compound, the second compound, the third compound, and the fourth compound. However, embodiments are not limited thereto. If an amount of the first compound satisfies the above-described range, energy transfer from the second compound and the third compound to the first compound may increase, and accordingly, emission efficiency and device lifetime may increase.
In the emission layer EML, a total amount of the second compound and the third compound may be the remainder of the total weight of the first compound, the second compound, the third compound, and the fourth compound, excluding the amount of the first compound and the fourth compound. For example, a combined amount of the second compound and the third compound may be in a range of about 65 wt % to about 95 wt %, based on a total weight of the first compound, the second compound, the third compound, and the fourth compound.
Within the combined amount of the second compound and the third compound in the emission layer EML, a weight ratio of the second compound to the third compound may be in a range of about 3:7 to about 7:3.
If the amounts of the second compound and the third compound satisfy the above-described ranges and ratios, charge balance properties in the emission layer EML may be improved, and emission efficiency and device lifetime may be improved. If the amounts of the second compound and the third compound deviate from the above-described ranges and ratios, charge balance in the emission layer EML may not be achieved, so that emission efficiency may be reduced, and the device may readily deteriorate.
If the emission layer EML includes the fourth compound, an amount of the fourth compound in the emission layer EML may be in a range of about 4 wt % to 30 wt %, based on a total weight of the first compound, the second compound, the third compound, and the fourth compound. However, embodiments are not limited thereto. If an amount of the fourth compound satisfies the above-described range, energy transfer from a host to the first compound, which is a light emitting dopant, may increase so that an emission ratio may improve. Accordingly, emission efficiency of the emission layer EML may improve. If the amounts of the first compound, the second compound, the third compound, and the fourth compound included in the emission layer EML satisfy the above-described ranges and ratios, excellent emission efficiency and long lifetime may be achieved.
In the light emitting element ED, the emission layer EML may further include an anthracene derivative, a pyrene derivative, a fluoranthene derivative, a chrysene derivative, a dihydrobenzanthracene derivative, or a triphenylene derivative. For example, the emission layer EML may include an anthracene derivative or a pyrene derivative.
In the light emitting elements ED according to embodiments as shown in each of
In an embodiment, the emission layer EML may include a compound represented by Formula E-1. The compound represented by Formula E-1 may be used as a fluorescence host material.
In Formula E-1, R31 to R40 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, or bonded to an adjacent group to form a ring. For example, R31 to R40 may be combined with an adjacent group to form a saturated hydrocarbon ring, an unsaturated hydrocarbon ring, a saturated heterocycle, or an unsaturated heterocycle.
In Formula E-1, c and d may each independently be an integer from 0 to 5.
In an embodiment, the compound represented by Formula E-1 may be any compound selected from Compound E1 to Compound E19:
In an embodiment, the emission layer EML may include a compound represented by Formula E-2a or Formula E-2b. The compound represented by Formula E-2a or Formula E-2b may be used as a phosphorescence host material.
In Formula E-2a, a may be an integer from 0 to 10; and La may be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms. If a is 2 or more, multiple La groups may each independently be a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms.
In Formula E-2a, A1 to A5 may each independently be N or C(Ri). In Formula E-2a, Ra to Ri may each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted amine group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, or bonded to an adjacent group to form a ring. For example, Ra to Ri may be combined with an adjacent group to form a hydrocarbon ring or a heterocycle including N, O, S, etc. as a ring-forming atom.
In Formula E-2a, two or three of Ai to A5 may each be N, and the remainder of A1 to A5 may each independently be C(Ri).
In Formula E-2b, Cbz1 and Cbz2 may each independently be an unsubstituted carbazole group or a carbazole group substituted with an aryl group having 6 to 30 ring-forming carbon atoms. In Formula E-2b, Lb may be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms. In Formula E-2b, b may be an integer from 0 to 10. If b is 2 or more, multiple Lb groups may each independently be a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms.
The compound represented by Formula E-2a or Formula E-2b may be any compound selected from Compound Group E-2. However, the compounds shown in Compound Group E-2 are only examples, and the compound represented by Formula E-2a or Formula E-2b is not limited to Compound Group E-2:
The emission layer EML may further include a material of the related art as a host material. For example, the emission layer EML may include as a host material, at least one of bis(4-(9H-carbazol-9-yl)phenyl) diphenylsilane (BCPDS), (4-(1-(4-(diphenylamino)phenyl) cyclohexyl)phenyl) diphenyl-phosphine oxide (POPCPA), bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-bis(carbazol-9-yl)benzene (mCP), 2,8-bis(diphenylphosphoryl)dibenzo[b,d]furan (PPF), 4,4′,4″-tris(carbazol-9-yl)-triphenylamine (TCTA), and 1,3,5-tris(1-phenyl-1H-benzo[d]imidazole-2-yl)benzene (TPBi). However, embodiments are not limited thereto. For example, tris(8-hydroxyquinolinato)aluminum (Alq3), 9,10-di(naphthalene-2-yl)anthracene (ADN), 2-tert-butyl-9, 10-di(naphth-2-yl)anthracene (TBADN), distyrylarylene (DSA), 4,4′-bis(9-carbazolyl)-2,2′-dimethyl-biphenyl (CDBP), 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), hexaphenyl cyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO3), octaphenylcyclotetra siloxane (DPSiO4), etc. may be used as a host material.
In an embodiment, the emission layer EML may include a compound represented by Formula M-a. The compound represented by Formula M-a may be used as a phosphorescence dopant material.
In Formula M-a, Y1 to Y4 and Z1 to Z4 may each independently be C(R1) or N; and R1 to R4 may each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted amine group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, or bonded to an adjacent group to form a ring. In Formula M-a, m may be 0 or 1, and n may be 2 or 3. In Formula M-a, if m is 0, n may be 3, and if m is 1, n may be 2.
The compound represented by Formula M-a may be any compound selected from Compounds M-al to M-a25. However, Compounds M-al to M-a25 are only examples, and the compound represented by Formula M-a is not limited to Compounds M-al to M-a25:
In an embodiment, the emission layer EML may include a compound represented by one of Formula F-a to Formula F-c. The compound represented by one of Formula F-a to Formula F-c may be used as a fluorescence dopant material.
In Formula F-a, two of Ra to Ri may each independently be substituted with a group represented by . The remainder of Ra to Ri which are not substituted with the group represented by
may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.
In the group represented by , Ar1 and Ar2 may each independently be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, at least one of Ar1 and Ar2 may each independently be a heteroaryl group including O or S as a ring-forming atom.
In Formula F-b, Ra and Rb may each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, or bonded to an adjacent group to form a ring. In Formula F-b, Ar1 to Ar4 may each independently be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, at least one of Ar1 to Ar4 may each independently be a heteroaryl group including O or S as a ring-forming atom.
In Formula F-b, U and V may each independently be a substituted or unsubstituted hydrocarbon ring having 5 to 30 ring-forming carbon atoms or a substituted or unsubstituted heterocycle having 2 to 30 ring-forming carbon atoms.
In Formula F-b, the number of rings represented by U and V may each independently be 0 or 1. If the number of U or V is 1, a fused ring may be present at the portion indicated by U or V, and if the number of U or V is 0, a fused ring may not be present at the portion indicated by U or V. If the number of U is 0 and the number of V is 1, or if the number of U is 1 and the number of V is 0, a fused ring having the fluorene core of Formula F-b may be a cyclic compound with four rings. If the number of U and V is each 0, a fused ring having the fluorene core of Formula F-b may be a cyclic compound with three rings. If the number of U and V is each 1, a fused ring having the fluorene core of Formula F-b may be a cyclic compound with five rings.
In Formula F-c, A1 and A2 may each independently be O, S, Se, or N(Rm); and Rm may be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. In Formula F-c, R1 to R11 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted amine group, a substituted or unsubstituted boryl group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, or bonded to an adjacent group to form a ring.
In Formula F-c, A1 and A2 may each independently be bonded to a substituent of an adjacent ring to form a fused ring. For example, if A1 and A2 are each independently N(Rm), Ai may be combined with R4 or R5 to form a ring. For example, A2 may be combined with R7 or R8 to form a ring.
In an embodiment, the emission layer EML may include, as a dopant material of the related art, a styryl derivative (for example, 1,4-bis[2-(3-N-ethylcarbazoryl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4′-[(di-p-tolylamino)styryl]stilbene (DPAVB), N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzenamine (N-BDAVBi), and 4,4′-bis[2-(4-(N,N-diphenylamino)phenyl)vinyl]biphenyl(DPAVBi)), perylene or a derivative thereof (for example, 2,5,8,11-tetra-t-butylperylene (TBP)), pyrene or a derivative thereof (for example, 1,1-dipyrene, 1,4-dipyrenylbenzene, and 1,4-bis(N,N-diphenylamino)pyrene), etc.
The emission layer EML may include a phosphorescence dopant material of the related art. For example, the phosphorescence dopant may include a metal complex including iridium (Ir), platinum (Pt), osmium (Os), gold (Au), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), or thulium (Tm). For example, iridium(III) bis(4,6-difluorophenylpyridinato-N,C2′)picolinate (FIrpic), bis(2,4-difluorophenylpyridinato)-tetrakis(1-pyrazolyl)borate iridium(III) (Fir6), or platinum octaethyl porphyrin (PtOEP) may be used as a phosphorescence dopant. However, embodiments are not limited thereto.
In an embodiment, the emission layer may include a quantum dot.
In the specification, a quantum dot may be a crystal of a semiconductor compound. The quantum dot may emit light in various emission wavelengths according to a size of the crystal. The quantum dot may emit light in various emission wavelengths by controlling an elemental ratio of a quantum dot compound.
A diameter of the quantum dot may be, for example, in a range of about 1 nm to about 10 nm.
The quantum dot may be synthesized by chemical bath deposition, metal organic chemical vapor deposition, molecular beam epitaxy, or a similar process.
A chemical bath deposition is a method of mixing an organic solvent and a precursor material and growing a quantum dot particle crystal. While growing the crystal, the organic solvent may serve as a dispersant that is coordinated on a surface of the quantum dot crystal and may control the growth of the crystal. Accordingly, chemical bath deposition may be more advantageous when compared to a vapor deposition method such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE), and the growth of a quantum dot particle may be controlled through a low-cost process.
In an embodiment, the emission layer EML may include a quantum dot material. The quantum dot may be a Group II-VI compound, a Group III-VI compound, a Group 1-II-VI compound, a Group III-V compound, a Group III-II-V compound, a Group IV-VI compound, a Group IV element, a Group IV compound, or any combination thereof.
Examples of a Group II-VI compound may include: a binary compound selected from the group consisting of CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and a mixture thereof; a ternary compound selected from the group consisting of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, and a mixture thereof; a quaternary compound selected from the group consisting of HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and a mixture thereof; or any combination thereof.
In an embodiment, a Group II-VI compound may further include a Group I metal and/or a Group IV element. Examples of a Group 1-II-VI compound may include CuSnS or CuZnS. Examples of a Group II-IV-VI compound include ZnSnS and the like. Examples of a Group I-II-IV-VI compound may include a quaternary compound selected from the group consisting of Cu2ZnSnS2, Cu2ZnSnS4, Cu2ZnSnSe4, Ag2ZnSnS2, and a mixture thereof.
Examples of a Group III-VI compound may include: a binary compound such as In2S3, and In2Se3; a ternary compound such as InGaS3 and InGaSe3; or any combination thereof.
Examples of a Group 1-III-VI compound may include: a ternary compound selected from the group consisting of AgInS, AgInS2, CuInS, CuInS2, AgGaS2, CuGaS2, CuGaO2, AgGaO2, AgAlO2, and mixtures thereof; a quaternary compound such as AgInGaS2 and CuInGaS2; or any combination thereof.
Examples of a Group III-V compound may include: a binary compound selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; a ternary compound selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InAlP, InNP, InNAs, InNSb, InPAs, InPSb, and mixtures thereof; a quaternary compound selected from the group consisting of GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof; or any combination thereof. In an embodiment, a Group III-V compound may further include a Group II metal. Examples of a Group III-II-V compound may include InZnP, etc.
Examples of a Group IV-VI compound may include: a binary compound selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and a mixture thereof; a ternary compound selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and a mixture thereof; a quaternary compound selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and a mixture thereof; or any combination thereof.
Examples of a Group II-IV-V compound may include a ternary compound selected from the group consisting of ZnSnP, ZnSnP2, ZnSnAs2, ZnGeP2, ZnGeAs2, CdSnP2, CdGeP2, and a mixture thereof.
Examples of a Group IV element may include Si, Ge, and a mixture thereof. Examples of a Group IV compound may include a binary compound selected from the group consisting of SiC, SiGe, and a mixture thereof.
Each element included in a multi-element compound, such as a binary compound, a ternary compound, or a quaternary compound, may be present in a particle at a uniform concentration or at a non-uniform concentration. For example, a formula may indicate the elements that are included in a compound, but an elemental ratio in the compound may vary.
For example, AgInGaS2 may indicate AgInxGa1-xS2 (where x is a real number between 0 and 1).
A binary compound, a ternary compound, or a quaternary compound may be present in a particle at a uniform concentration or may be present in a particle at a partially different concentration distribution state. In an embodiment, a quantum dot may have a core/shell structure in which one quantum dot surrounds another quantum dot. An interface between the core and the shell may have a concentration gradient in which the concentration of an element that is present in the shell decreases toward the core.
In embodiments, the quantum dot may have the above-described core-shell structure including a core that includes a nanocrystal and a shell that surrounds the core. The shell of a quantum dot may serve as a protection layer that prevents chemical deformation of the core to maintain semiconductor properties and/or may serve as a charging layer that imparts the quantum dot with electrophoretic properties. The shell may be a single layer or a multilayer. Examples of a shell of a quantum dot may include a metal oxide, a non-metal oxide, a semiconductor compound, or any combination thereof.
Examples of a metal oxide or a non-metal oxide may include a binary compound such as SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, CO3O4 and NiO; or a ternary compound such as MgAl2O4, CoFe2O4, NiFe2O4 and CoMn2O4. However, embodiments are not limited thereto.
Examples of a semiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, etc., but embodiments are not limited thereto.
The quantum dot may have a full width at half maximum (FWHM) of an emission spectrum equal to or less than about 45 nm. For example, the quantum dot may have a FWHM of an emission spectrum equal to or less than about 40 nm. For example, the quantum dot may have a FWHM of an emission spectrum equal to or less than about 30 nm. Within any of the above ranges, color purity or color reproducibility may be improved. Light that is emitted through a quantum dot may be emitted in all directions, so that light viewing angle properties may be improved.
The shape of a quantum dot may be any shape that is used in the related art. For example, a quantum dot may have a spherical shape, a pyramidal shape, a multi-arm shape, or a cubic shape, or the quantum dot may be the form of a nanoparticle, a nanotube, a nanowire, a nanofiber, a nanoplate particle, etc.
As a size of the quantum dot or an elemental ratio of the quantum dot compound is adjusted, the energy band gap may be accordingly controlled to obtain light of various wavelengths from a quantum dot emission layer. Therefore, by using quantum dots as described above (for example, using quantum dots of different sizes or having different elemental ratios in the quantum dot compound), a light emitting element that emits light of various wavelengths may be achieved. For example, the size of the quantum dots or the elemental ratio of a quantum dot compound may be adjusted to emit red light, green light, and/or blue light. For example, the quantum dots may be configured to emit white light by combining light of various colors.
In the light emitting elements ED according to embodiments as shown in each of
The electron transport region ETR may be a layer consisting of a single material, a layer including different materials, or a structure including multiple layers including different materials.
For example, the electron transport region ETR may have a single layer structure of an electron injection layer EIL or an electron transport layer ETL, or may have a single layer structure formed of an electron injection material and an electron transport material. In other embodiments, the electron transport region ETR may have a single layer structure formed of different materials, or may have a structure in which an electron transport layer ETL/electron injection layer EIL, or a hole blocking layer HBL/electron transport layer ETL/electron injection layer EIL are stacked in its respective stated order from the emission layer EML, but embodiments are not limited thereto. A thickness of the electron transport region ETR may be, for example, in a range of about 1,000 Å to about 1,500 Å.
The electron transport region ETR may be formed using various methods such as a vacuum deposition method, a spin coating method, a cast method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, and a laser induced thermal imaging (LITI) method.
In the light emitting element ED according to an embodiment, the electron transport region ETR may include a compound represented by Formula ET-2:
In Formula ET-2, at least one of X1 to X3 may each be N, and the remainder of X1 to X3 may each independently be C(Ra). In Formula ET-2, Ra may be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. In Formula ET-2, Ar1 to Ar3 may each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.
In Formula ET-2, a to c may each independently be an integer from 0 to 10. In Formula ET-2, L1 to L3 may each independently be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms. If a to c are each 2 or more, multiple groups of each of L1 to L3 may each independently be a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms.
The electron transport region ETR may include an anthracene-based compound. However, embodiments are not limited thereto, and the electron transport region ETR may include, for example, tris(8-hydroxyquinolinato)aluminum (Alq3), 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, 2,4,6-tris(3′-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzoimidazolyl-1-yl)phenyl)-9,10-dinaphthylanthracene, 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), bis(2-methyl-8-quinolinolato-N1,08)-(1,1′-biphenyl-4-olato)aluminum (BAlq), beryllium bis(benzoquinolin-10-olate) (Bebg2), 9,10-di(naphthalene-2-yl)anthracene (ADN), 1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene (BmPyPhB), CNNPTRZ (4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile), or a mixture thereof, without limitation.
In an embodiment, the electron transport region ETR may include a compound selected from Compound Group 3.
In an embodiment, the electron transport region ETR may include at least one compound selected from Compounds ET1 to ET36:
In an embodiment, the electron transport region ETR may include a metal halide such as LiF, NaCl, CsF, RbCl, RbI, CuI, and KI; a lanthanide metal such as Yb; or a co-deposited material of a metal halide and a lanthanide metal. For example, the electron transport region ETR may include KJ:Yb, RbJ:Yb, LiF:Yb, etc., as a co-deposited material. The electron transport region ETR may include a metal oxide such as Li2O and BaO, or 8-hydroxy-lithium quinolate (Liq). However, embodiments are not limited thereto. The electron transport region ETR may also be formed of a mixture material of an electron transport material and an insulating organometallic salt. The insulating organometallic salt may be a material having an energy band gap equal to or greater than about 4 eV. For example, the insulating organometallic salt may include a metal acetate, a metal benzoate, a metal acetoacetate, a metal acetylacetonate, or a metal stearate.
The electron transport region ETR may include at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), diphenyl(4-(triphenylsilyl)phenyl)phosphine oxide (TSPO1) or 4,7-diphenyl-1,10-phenanthroline (Bphen), in addition to the aforementioned materials. However, embodiments are not limited thereto.
The electron transport region ETR may include the compounds of the electron transport region ETR in at least one of an electron injection layer EIL, an electron transport layer ETL, and a hole blocking layer HBL.
If the electron transport region ETR includes an electron transport layer ETL, a thickness of the electron transport layer ETL may be in a range of about 100 Å to about 1,000 Å. For example, the thickness of the electron transport layer ETL may be in a range of about 150 Å to about 500 Å. If the thickness of the electron transport layer ETL satisfies any of the above-described ranges, satisfactory electron transport properties may be obtained without a substantial increase of driving voltage. If the electron transport region ETR includes an electron injection layer EIL, a thickness of the electron injection layer EIL may be in a range of about 1 Å to about 100 Å. For example, the thickness of the electron injection layer EIL may be in a range of about 3 Å to about 90 Å. If the thickness of the electron injection layer EIL satisfies any of the above described ranges, satisfactory electron injection properties may be obtained without inducing a substantial increase of driving voltage.
The second electrode EL2 may be provided on the electron transport region ETR. The second electrode EL2 may be a common electrode. The second electrode EL2 may be a cathode or an anode, but embodiments are not limited thereto. For example, if the first electrode EL1 is an anode, the second cathode EL2 may be a cathode, and if the first electrode EL1 is a cathode, the second electrode EL2 may be an anode.
The second electrode EL2 may be a transmissive electrode, a transflective electrode, or a reflective electrode. If the second electrode EL2 is a transmissive electrode, the second electrode EL2 may include a transparent metal oxide, for example, ITO, IZO, ZnO, ITZO, etc.
If the second electrode EL2 is a transflective electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF/Ca, LiF/Al, Mo, Ti, Yb, W, a compound thereof, or a mixture thereof (for example, AgMg, AgYb, or MgYb). In an embodiment, the second electrode EL2 may have a multilayered structure including a reflective layer or a transflective layer formed of the above-described materials and a transparent conductive layer formed of ITO, IZO, ZnO, ITZO, etc. For example, the second electrode EL2 may include the aforementioned metal materials, combinations of two or more metal materials selected from the aforementioned metal materials, or oxides of the aforementioned metal materials.
Although not shown in the drawings, the second electrode EL2 may be electrically connected to an auxiliary electrode. If the second electrode EL2 is electrically connected to an auxiliary electrode, resistance of the second electrode EL2 may decrease.
In an embodiment, the light emitting element ED may further include a capping layer CPL disposed on the second electrode EL2. The capping layer CPL may be a multilayer or a single layer.
In an embodiment, the capping layer CPL may include an organic layer or an inorganic layer. For example, if the capping layer CPL includes an inorganic material, the inorganic material may include an alkali metal compound such as LiF, an alkaline earth metal compound such as MgF2, SiON, SiNx, SiOy, etc.
For example, if the capping layer CPL includes an organic material, the organic material may include 2,2′-dimethyl-N,N′-di-[(1-naphthyl)-N,N′-diphenyl]-1,1′-biphenyl-4,4′-diamine(a-NPD), NPB, TPD, m-MTDATA, Alq3, CuPc, N4,N4,N4′,N4′-tetra(biphenyl-4-yl) biphenyl-4,4′-diamine (TPD15), 4,4′,4″-tris(carbazol sol-9-yl)triphenylamine (TCTA), etc., or may include an epoxy resin, or an acrylate such as methacrylate. In an embodiment, the capping layer CPL may include at least one of Compounds P1 to P5, but embodiments are not limited thereto
A refractive index of the capping layer CPL may be equal to or greater than about 1.6. For example, the refractive index of the capping layer CPL may be equal to or greater than about 1.6, with respect to light in a wavelength range of about 550 nm to about 660 nm.
Referring to
In an embodiment shown in
The light emitting element ED may include a first electrode EL1, a hole transport region HTR disposed on the first electrode EL1, an emission layer EML disposed on the hole transport region HTR, an electron transport region ETR disposed on the emission layer EML, and a second electrode EL2 disposed on the electron transport region ETR. In embodiments, a structure of the light emitting element ED shown in
The emission layer EML of the light emitting element ED included in the display device DD-a according to an embodiment may include the fused polycyclic compound according to an embodiment as described above.
Referring to
The light controlling layer CCL may be disposed on the display panel DP. The light controlling layer CCL may include a light converter. The light converter may be a quantum dot or a phosphor. The light converter may convert the wavelength of a provided light and emit the resulting light. For example, the light controlling layer CCL may be a layer including a quantum dot or a layer including a phosphor.
The light controlling layer CCL may include light controlling parts CCP1, CCP2, and CCP3. The light controlling parts CCP1, CCP2, and CCP3 may be spaced apart from each other.
Referring to
The light controlling layer CCL may include a first light controlling part CCP1 including a first quantum dot QD1 that converts first color light provided from the light emitting element ED into second color light, a second light controlling part CCP2 including a second quantum dot QD2 that converts first color light into third color light, and a third light controlling part CCP3 that transmits first color light.
In an embodiment, the first light controlling part CCP1 may provide red light, which is the second color light, and the second light controlling part CCP2 may provide green light, which is the third color light. The third color controlling part CCP3 may transmit and provide blue light, which is the first color light provided from the light emitting element ED. For example, the first quantum dot QD1 may be a red quantum dot, and the second quantum dot QD2 may be a green quantum dot. The quantum dots QD1 and QD2 may each be a quantum dot as described above.
The light controlling layer CCL may further include a scatterer SP. The first light controlling part CCP1 may include the first quantum dot QD1 and the scatterer SP, the second light controlling part CCP2 may include the second quantum dot QD2 and the scatterer SP, and the third light controlling part CCP3 may not include a quantum dot but may include the scatterer SP.
The scatterer SP may be an inorganic particle. For example, the scatterer SP may include at least one of TiO2, ZnO, Al2O3, SiO2, and hollow silica. The scatterer SP may include at least one of TiO2, ZnO, Al2O3, SiO2, and hollow silica, or may be a mixture of two or more materials selected from TiO2, ZnO, Al2O3, SiO2, and hollow silica.
The first light controlling part CCP1, the second light controlling part CCP2, and the third light controlling part CCP3 may include base resins BR1, BR2, and BR3, in which the quantum dots QD1 and QD2 and the scatterer SP are dispersed. In an embodiment, the first light controlling part CCP1 may include the first quantum dot QD1 and the scatterer SP dispersed in the first base resin BR1, the second light controlling part CCP2 may include the second quantum dot QD2 and the scatterer SP dispersed in the second base resin BR2, and the third light controlling part CCP3 may include the scatterer particle SP dispersed in the third base resin BR3.
The base resins BR1, BR2, and BR3 are mediums in which the quantum dots QD1 and QD2 and the scatterer SP are dispersed, and may be composed of various resin compositions which may be generally referred to as a binder. For example, the base resins BR1, BR2, and BR3 may be acrylic resins, urethane-based resins, silicone-based resins, epoxy-based resins, etc. The base resins BR1, BR2, and BR3 may each be a transparent resin. In an embodiment, the first base resin BRi, the second base resin BR2, and the third base resin BR3 may be the same as or different from each other.
The light controlling layer CCL may include a barrier layer BFL1. The barrier layer BFL1 may block the penetration of moisture and/or oxygen (hereinafter, will be referred to as “humidity/oxygen”). The barrier layer BFL1 may block the light controlling parts CCP1, CCP2, and CCP3 from exposure to humidity/oxygen. The barrier layer BFL1 may cover the light controlling parts CCP1, CCP2, and CCP3. A color filter layer CFL, which will be explained later, may include a barrier layer BFL2 disposed on the light controlling parts CCP1, CCP2, and CCP3.
The barrier layers BFL1 and BFL2 may each independently include at least one inorganic layer. For example, the barrier layers BFL1 and BFL2 may each independently include an inorganic material. For example, the barrier layers BFL1 and BFL2 may each independently include silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide, silicon oxynitride, or a metal thin film securing light transmittance. The barrier layers BFL1 and BFL2 may each independently further include an organic layer. The barrier layers BFL1 and BFL2 may each be formed of a single layer or formed of multiple layers.
In the display device DD-a, the color filter layer CFL may be disposed on the light controlling layer CCL. In an embodiment, the color filter layer CFL may be directly disposed on the light controlling layer CCL. For example, the barrier layer BFL2 may be omitted.
The color filter layer CFL may include filters CF1, CF2, and CF3. The first to third filters CF1, CF2, and CF3 may be disposed to respectively correspond a red light emitting region PXA-R, a green light emitting region PXA-G, and a blue light emitting region PXA-B.
The color filter layer CFL may include a first filter CF1 that transmits second color light, a second filter CF2 that transmits third color light, and a third filter CF3 that transmits first color light. For example, the first filter CF1 may be a red filter, the second filter CF2 may be a green filter, and the third filter CF3 may be a blue filter. The filters CF1, CF2, and CF3 may each include a polymer photosensitive resin and a pigment or dye. The first filter CF1 may include a red pigment or dye, the second filter CF2 may include a green pigment or dye, and the third filter CF3 may include a blue pigment or dye.
However, embodiments are not limited thereto, and the third filter CF3 may not include a pigment or dye. The third filter CF3 may include a polymer photosensitive resin and may not include a pigment or dye. The third filter CF3 may be transparent. The third filter CF3 may be formed of a transparent photosensitive resin.
In an embodiment, the first filter CF1 and the second filter CF2 may each be a yellow filter. The first filter CF1 and the second filter CF2 may be provided in one body, without distinction.
Although not shown in the drawings, the color filter layer CFL may further include a light blocking part (not shown). The light blocking part (not shown) may be a black matrix. The light blocking part (not shown) may include an organic light blocking material or an inorganic light blocking material, each including a black pigment or a black dye. The light blocking part (not shown) may prevent light leakage, and may separate the boundaries between adjacent filters CF1, CF2, and CF3.
A base substrate BL may be disposed on the color filter layer CFL. The base substrate BL may provide a base surface on which the color filter layer CFL, the light controlling layer CCL, etc. are disposed. The base substrate BL may be a glass substrate, a metal substrate, a plastic substrate, etc. However, embodiments are not limited thereto, and the base substrate BL may include an inorganic layer, an organic layer, or a composite material layer. Although not shown in the drawings, in an embodiment, the base substrate BL may be omitted.
The light emitting element ED-BT may include a first electrode EL1 and a second electrode EL2 which face each other, and the light emitting structures OL-B1, OL-B2, and OL-B3 stacked in a thickness direction between the first electrode EL1 and the second electrode EL2. The light emitting structures OL-B1, OL-B2, and OL-B3 may each include a hole transport region HTR, an emission layer EML (
For example, the light emitting element ED-BT included in the display device DD-TD may be a light emitting element having a tandem structure and including multiple emission layers.
In an embodiment shown in
Charge generating layers CGL1 and CGL2 may each be disposed between neighboring light emitting structures among the light emitting structures OL-B1, OL-B2, and OL-B3. Charge generating layers CGL1 and CGL2 may each independently include a p-type charge generating layer and/or an n-type charge generating layer.
At least one of the light emitting structures OL-B1, OL-B2, and OL-B3 in the display device DD-TD may include the above-described fused polycyclic compound according to an embodiment. For example, at least one of the emission layers included in the light emitting element ED-BT may include the fused polycyclic compound.
Referring to
The first light emitting element ED-1 may include a first red emission layer EML-R1 and a second red emission layer EML-R2. The second light emitting element ED-2 may include a first green emission layer EML-G1 and a second green emission layer EML-G2. The third light emitting element ED-3 may include a first blue emission layer EML-B1 and a second blue emission layer EML-B2. An emission auxiliary part OG may be disposed between the first red emission layer EML-R1 and the second red emission layer EML-R2, between the first green emission layer EML-G1 and the second green emission layer EML-G2, and between the first blue emission layer EML-B1 and the second blue emission layer EML-B2.
The emission auxiliary part OG may be a single layer or a multilayer. The emission auxiliary part OG may include a charge generating layer. For example, the emission auxiliary part OG may include an electron transport region, a charge generating layer, and a hole transport region, which may be stacked in that order. The emission auxiliary part OG may be provided as a common layer for each of the first to third light emitting elements ED-1, ED-2, and ED-3.
However, embodiments are not limited thereto, and the emission auxiliary part OG may be provided by being patterned in the openings OH defined in the pixel defining film PDL.
The first red emission layer EML-R1, the first green emission layer EML-G1 and the first blue emission layer EML-B1 may each be disposed between the electron transport region ETR and the emission auxiliary part OG. The second red emission layer EML-R2, the second green emission layer EML-G2 and the second blue emission layer EML-B2 may each be disposed between the emission auxiliary part OG and the hole transport region HTR.
For example, the first light emitting element ED-1 may include a first electrode EL1, a hole transport region HTR, a second red emission layer EML-R2, an emission auxiliary part OG, a first red emission layer EML-R1, an electron transport region ETR, and a second electrode EL2, which are stacked in that order. The second light emitting element ED-2 may include a first electrode EL1, a hole transport region HTR, a second green emission layer EML-G2, an emission auxiliary part OG, a first green emission layer EML-G1, an electron transport region ETR, and a second electrode EL2, which are stacked in that order. The third light emitting element ED-3 may include a first electrode EL1, a hole transport region HTR, a second blue emission layer EML-B2, an emission auxiliary part OG, a first blue emission layer EML-B1, an electron transport region ETR, and a second electrode EL2, which are stacked in that order.
An optical auxiliary layer PL may be disposed on the display device layer DP-ED. The optical auxiliary layer PL may include a polarization layer. The optical auxiliary layer PL may be disposed on the display panel DP and may control light that is reflected at the display panel DP from an external light. Although not shown in the drawings, in an embodiment, the optical auxiliary layer PL may be omitted from the display device DD-b.
At least one emission layer included in the display device DD-b shown in
In contrast to
Charge generating layers CGL1, CGL2, and CGL3 may each be disposed between adjacent light emitting structures among the first to fourth light emitting structures OL-B1, OL-B2, OL-B3, and OL-C1. For example, a first charge generating layer CGL1 may be disposed between the first light emitting structure OL-B1 and the fourth light emitting structure OL-C1.
For example, a second charge generating layer CGL2 may be disposed between the first light emitting structure OL-B1 and the second light emitting structure OL-B2. For example, a third charge generating layer CGL3 may be disposed between the second light emitting structure OL-B2, and the third light emitting structure OL-B3.
Among the four light emitting structures, the first to third light emitting structures OL-B1, OL-B2, and OL-B3 may each emit blue light, and the fourth light emitting structure OL-C1 may emit green light. However, embodiments are not limited thereto, and the first to fourth light emitting structures OL-B1, OL-B2, OL-B3, and OL-C1 may emit light having different wavelengths from each other.
The charge generating layers CGL1, CGL2, and CGL3 that are disposed between neighboring light emitting structures among the first to fourth light emitting structures OL-B1, OL-B2, OL-B3, and OL-C1 may each independently include a p-type charge generating layer and/or an n-type charge generating layer.
In the display device DD-c, at least one of the light emitting structures OL-B1, OL-B2, OL-B3, and OL-C1 may each independently include the fused polycyclic compound according to an embodiment as described above. For example, in an embodiment, at least one among the first to third light emitting structures OL-B1, OL-B2, and OL-B3 may each independently include the fused polycyclic compound.
The light emitting element ED according to an embodiment may include the fused polycyclic compound according to an embodiment in at least one functional layer disposed between the first electrode EL1 and the second electrode EL2, thereby exhibiting excellent emission efficiency and improved service life characteristics. For example, the emission layer EML of the light emitting element ED may include the fused polycyclic compound, and the light emitting element ED may exhibit a long service life.
In an embodiment, an electronic apparatus may include a display device that includes multiple light emitting elements and a control part that controls the display device. The electronic apparatus may be a device that is activated according to electrical signals. The electronic apparatus may include display devices according to various embodiments. Examples of an electronic apparatus may include a television, a monitor, a large display device such as a billboard, a personal computer, a laptop computer, a personal digital terminal, a display device for a vehicle, a game console, a portable electronic device, and a medium-sized or a small display devices such as a camera.
In
At least one of the first to fourth display elements DD-1, DD-2, DD-3, and DD-4 may each independently include a light emitting element ED according to an embodiment as described with reference to any of
Referring to
A first display device DD-1 may be disposed in a first region that overlaps the steering wheel HA. For example, the first display device DD-1 may be a digital cluster that displays first information of the vehicle AM. The first information may include a first scale that indicates a driving speed of the vehicle AM, a second scale that indicates an engine speed (for example, as revolutions per minute (RPM)), a fuel gauge, and the like. The first scale and the second scale may be represented by digital images.
A second display device DD-2 may be disposed in a second region facing a driver's seat and overlapping the front window GL. The driver's seat may be a seat where the steering wheel HA is disposed. For example, the second display device DD-2 may be a head up display (HUD) that shows second information of the vehicle AM. The second display device DD-2 may be optically transparent. The second information may include digital numbers that indicate a driving speed of the vehicle AM and may further include information such as the current time.
Although not shown in the drawings, in an embodiment, the second information of the second display device DD-2 may be displayed by being projected onto the front window GL.
A third display device DD-3 may be disposed in a third region adjacent to the gearshift GR. For example, the third display device DD-3 may be a center information display (CID) for the vehicle AM that is disposed between a driver's seat and a passenger seat and which displays third information. The passenger seat may be a seat that is spaced apart from the driver's seat, and the gearshift GR may be disposed between the driver's seat and the passenger seat. The third information may include information on traffic or road conditions (for example, navigation information), playing music or radio, displaying an image or video, the temperature in the vehicle AM, or the like.
A fourth display device DD-4 may be disposed in a fourth region that is spaced apart from the steering wheel HA and the gearshift GR and adjacent to a side of the vehicle AM. For example, the fourth display device DD-4 may be a digital side-view mirror that displays fourth information. The fourth display device DD-4 may display an image that is exterior to the vehicle AM that is taken by a camera module CM disposed outside the vehicle AM. The fourth information may include an image of the exterior of the vehicle AM.
The first to fourth information as described above are only provided as examples, and the first to fourth display devices DD-1, DD-2, DD-3, and DD-4 may further display information about the interior and exterior of the vehicle AM. The first to fourth information may include information that is different from each other. However, embodiments are not limited thereto, and a portion of the first to fourth information may include the same information.
Hereinafter, a fused polycyclic compound according to an embodiment and a light emitting element according to an embodiment will be described with reference to the Examples and the Comparative Examples. The Examples described below are only provided as illustrations to assist in understanding the disclosure, and the scope thereof is not limited thereto.
A synthesis method of the fused polycyclic compound according to an embodiment will be explained by describing synthesis methods for Compounds 5, 249, 285, 344, 346, and 347. The synthesis methods of the fused polycyclic compounds according to the following descriptions are provided only as examples, and the synthesis methods of the fused polycyclic compounds according to embodiments are not limited to the Examples below.
Compound 5 according to an example may be synthesized by, for example, the reaction below:
In an argon atmosphere, 1,3-dibromo-5-(tert-butyl)benzene (12 g, 41.09 mmol), [1,1′:3′,1″-terphenyl]-2′-amine (11.09 g, 45.2 mmol), Pd(dba)2 (2.36 g, 4.11 mmol), (tBu)3PHBF4 (2.38 g, 8.22 mmol), and tBuONa (9.08 g, 94.52 mmol) were added to 205 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 5-1 (10.5 g, yield 56%). The molecular weight of Intermediate 5-1 was about 456 as measured by FAB MS.
In an argon atmosphere, Intermediate 5-1 (10.2 g, 22.35 mmol), 4-(tert-butyl)-2,6-dibutylaniline (8.76 g, 33.52 mmol), Pd(dba)2 (1.29 g, 2.23 mmol), (tBu)3PHBF4 (1.3 g, 4.47 mmol), and tBuONa (4.94 g, 51.4 mmol) were added to 111 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 5-2 (11.96 g, yield 84%). The molecular weight of Intermediate 5-2 was about 637 as measured by FAB MS.
A small amount of toluene (about 10 mL) was added to Intermediate 5-2 (11.5 g, 18.05 mmol), 4-iodo-1,1′-bipheny (75.86 g, 270.81 mmol), CuI (7.22 g, 37.91 mmol), and K2CO3 (19.96 g, 144.43 mmol), and the resultant mixture was heated for about 24 hours while maintaining the temperature at about 215° C. The mixture was diluted with CH2Cl2, water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 5-3 (14.96 g, yield 88%). The molecular weight of Intermediate 5-3 was about 941 as measured by FAB MS.
In an argon atmosphere, Intermediate 5-3 (14.0 g, 14.87 mmol) was dissolved in ODCB (149 mL), BBr3 (9.31 g, 37.18 mmol) was added thereto, and the resultant mixture was heated and stirred at about 170° C. for about 10 hours. The resultant mixture was cooled to room temperature, N,N-diisopropylethylamine (DIPEA, 23.02 g, 178.47 mmol) was added thereto, water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Compound 5 (4.66 g, yield 33%). The molecular weight of Compound 5 was about 949 as measured by FAB MS.
Sublimation purification was performed (320° C., 3.3×10−3 Pa) to perform device evaluation.
Compound 249 according to an example may be synthesized by, for example, the reaction below:
In an argon atmosphere, 1,3-dibromo-5-(tert-butyl)benzene (8.03 g, 27.5 mmol), 5′-(tert-butyl)-[1,1′:3′,1″-terphenyl]-2′-amine (8.7 g, 28.87 mmol), Pd(dba)2 (1.58 g, 2.75 mmol), (tBu)3PHBF4 (1.6 g, 5.5 mmol), and tBuONa (6.08 g, 63.25 mmol) were added to 137 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 249-1 (12.12 g, yield 86%). The molecular weight of Intermediate 249-1 was about 513 as measured by FAB MS.
In an argon atmosphere, Intermediate 249-1 (11.53 g, 22.5 mmol), 2-butyldibenzo[b,d]furan-1-amine (5.65 g, 23.62 mmol), Pd(dba)2 (1.29 g, 2.25 mmol), (tBu)3PHBF4 (1.31 g, 4.5 mmol), and tBuONa (4.97 g, 51.74 mmol) were added to 112 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 249-2 (13.89 g, yield 92%). The molecular weight of Intermediate 249-2 was about 671 as measured by FAB MS.
A small amount of toluene (about 10 mL) was added to Intermediate 249-2 (6.32 g, 9.42 mmol), 1-chloro-3-iodobenzene (33.69 g, 141.29 mmol), CuI (3.77 g, 19.78 mmol), and K2CO3 (10.42 g, 75.36 mmol), and the resultant mixture was heated for about 24 hours while maintaining the temperature at about 215° C. The mixture was diluted with CH2Cl2, water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 249-3 (7.39 g, yield 88%). The molecular weight of Intermediate 249-3 was about 892 as measured by FAB MS.
In an argon atmosphere, Intermediate 249-3 (7.11 g, 7.97 mmol) was dissolved in ODCB (80 mL), BBr3 (4.99 g, 19.93 mmol) was added thereto, and the resultant mixture was heated and stirred at about 170° C. for about 10 hours. The resultant mixture was cooled to room temperature, DIPEA (12.34 g, 95.65 mmol) was added thereto, water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 249-4 (3.87 g, yield 54%). The molecular weight of Intermediate 249-4 was about 900 as measured by FAB MS.
In an argon atmosphere, Intermediate 249-4 (3.55 g, 3.95 mmol), 7H-benzo[c]carbazole (1.65 g, 9.86 mmol), Pd(dba)2 (0.23 g, 0.39 mmol), (tBu)3PHBF4 (0.23 g, 0.79 mmol), and tBuONa (0.87 g, 9.07 mmol) were added to 19 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Compound 249 (1.7 g, yield 74%). The molecular weight of Compound 249 was about 1161 as measured by FAB MS.
Sublimation purification was performed (320° C., 3.3×10−3 Pa) to perform device evaluation.
Compound 285 according to an example may be synthesized by, for example, the reaction below:
In an argon atmosphere, 1,3-dibromo-5-(tert-butyl)benzene (10.2 g, 19.9 mmol), 4-(tert-butyl)-2,6-dibutylaniline (10.48 g, 43.78 mmol), Pd(dba)2 (1.14 g, 1.99 mmol), (tBu)3PHBF4 (1.15 g, 3.98 mmol), and tBuONa (5.74 g, 59.7 mmol) were added to 99 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 285-1 (10.95 g, yield 82%). The molecular weight of Intermediate 285-1 was about 671 as measured by FAB MS.
A small amount of toluene (about 10 mL) was added to Intermediate 285-2 (8.56 g, 13.11 mmol), 1-chloro-3-iodobenzene (46.88 g, 196.6 mmol), CuI (5.24 g, 27.52 mmol), and K2CO3 (14.49 g, 104.85 mmol), and the resultant mixture was heated for about 24 hours while maintaining the temperature at about 215° C. The mixture was diluted with CH2Cl2, water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 285-2 (9.74 g, yield 85%). The molecular weight of Intermediate 285-2 was about 874 as measured by FAB MS.
In an argon atmosphere, Intermediate 285-2 (9.66 g, 11.05 mmol) was dissolved in ODCB (111 mL), BBr3 (6.92 g, 27.63 mmol) was added thereto, and the resultant mixture was heated and stirred at about 170° C. for about 10 hours. The resultant mixture was cooled to room temperature, DIPEA (17.11 g, 132.6 mmol) was added thereto, water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 285-3 (6.04 g, yield 62%). The molecular weight of Intermediate 285-3 was about 882 as measured by FAB MS.
In an argon atmosphere, Intermediate 285-3 (5.76 g, 6.4 mmol), and 7H-benzo[c]carbazole (2.68 g, 16 mmol), Pd(dba)2 (0.37 g, 0.64 mol), (tBu)3PHBF4 (0.37 g, 1.28 mmol), and tBuONa (1.41 g, 14.72 mmol) were added to 32 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Compound 285 (2.74 g, yield 75%). The molecular weight of Compound 285 was about 1143 as measured by FAB MS.
Sublimation purification was performed (320° C., 3.3×10−3 Pa) to perform device evaluation.
Compound 344 according to an example may be synthesized, for example, by the reaction below:
In an argon atmosphere, 1,3-dibromo-5-(tert-butyl)benzene (5.36 g, 18.36 mmol), 3,5-dihexyl-[1,1′-biphenyl]-4-amine (6.2 g, 18.36 mmol), Pd(dba)2 (1.06 g, 1.84 mmol), (tBu)3PHBF4 (1.07 g, 3.67 mmol), and tBuONa (4.06 g, 42.22 mmol) were added to 91 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 344-1 (4.53 g, yield 45%). The molecular weight of Intermediate 344-1 was about 549 as measured by FAB MS.
In an argon atmosphere, Intermediate 344-1 (4.23 g, 7.71 mmol), 5′-(tert-butyl)-[1,1′:3′,1″-terphenyl]-2′-amine (3.02 g, 10.02 mmol), Pd(dba)2 (0.44 g, 0.77 mmol), (tBu)3PHBF4 (0.45 g, 1.54 mmol), and tBuONa (1.7 g, 17.73 mmol) were added to 38 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 344-2 (5.4 g, yield 91%). The molecular weight of Intermediate 344-2 was about 769 as measured by FAB MS.
A small amount of toluene (about 10 mL) was added to Intermediate 344-2 (5.14 g, 6.68 mmol), 1-chloro-3-iodobenzene (23.9 g, 100.24 mmol), CuI (2.67 g, 14.03 mmol), and K2CO3 (7.39 g, 53.46 mmol), and the resultant mixture was heated for about 24 hours while maintaining the temperature at about 215° C. The mixture was diluted with CH2Cl2, water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 344-3 (5.76 g, yield 87%). The molecular weight of Intermediate 344-3 was about 990 as measured by FAB MS.
In an argon atmosphere, Intermediate 344-3 (5.51 g, 5.56 mmol) was dissolved in ODCB (56 mL), BBr3 (3.48 g, 13.91 mmol) was added thereto, and the resultant mixture was heated and stirred at about 170° C. for about 10 hours. The resultant mixture was cooled to room temperature, DIPEA (8.61 g, 66.77 mmol) was added thereto, water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 344-(4) (4.11 g, yield 74%). The molecular weight of Intermediate 344-4 was about 998 as measured by FAB MS.
In an argon atmosphere, Intermediate 344-4 (5.26 g, 5.85 mmol), 7H-benzo[c]carbazole (2.44 g, 14.61 mmol), Pd(dba)2 (0.34 g, 0.58 mmol), (tBu)3PHBF4 (0.34 g, 1.17 mmol), and tBuONa (1.29 g, 13.45 mmol) were added to 29 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Compound 344 (2.76 g, yield 75%). The molecular weight of Compound 344 was about 1260 as measured by FAB MS.
Sublimation purification was performed (320° C., 3.3×10−3 Pa) to perform device evaluation.
Compound 346 according to an example may be synthesized by, for example, the reaction below:
In an argon atmosphere, 1,3-dibromo-5-(tert-butyl)benzene (5.01 g, 17.16 mmol), 3-hexyldibenzo[b,d]thiophen-4-amine (6.32 g, 22.3 mmol), Pd(dba)2 (0.99 g, 1.72 mmol), (tBu)3PHBF4 (1 g, 3.43 mmol), and tBuONa (3.79 g, 39.46 mmol) were added to 85 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 346-1 (3.48 g, yield 41%). The molecular weight of Intermediate 346-1 was about 495 as measured by FAB MS.
In an argon atmosphere, Intermediate 346-1 (3.22 g, 6.51 mmol), 5′-(tert-butyl)-[1,1′:3′,1″-terphenyl]-2′-amine (2.55 g, 8.46 mmol), Pd(dba)2 (0.37 g, 0.65 mmol), (tBu)3PHBF4 (0.38 g, 1.3 mmol), and tBuONa (1.44 g, 14.98 mmol) were added to 32 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 346-2 (4.00 g, yield 86%). The molecular weight of Intermediate 346-2 was about 715 as measured by FAB MS.
A small amount of toluene (about 10 mL) was added to Intermediate 346-3 (3.94 g, 5.51 mmol), 1-chloro-3-iodobenzene (19.71 g, 82.65 mmol), CuI (2.2 g, 11.57 mmol), and K2CO3 (6.09 g, 44.08 mmol), and the resultant mixture was heated for about 24 hours while maintaining the temperature at about 215° C. The mixture was diluted with CH2Cl2, water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 346-3 (4.23 g, yield 82%). The molecular weight of Intermediate 346-3 was about 936 as measured by FAB MS.
In an argon atmosphere, Intermediate 346-3 (4.06 g, 4.34 mmol) was dissolved in ODCB (43 mL), BBr3 (2.72 g, 10.84 mmol) was added thereto, and the resultant mixture was heated and stirred at about 170° C. for about 10 hours. The resultant mixture was cooled to room temperature, DIPEA (6.71 g, 52.04 mmol) was added thereto, water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 346-4 (2.95 g, yield 72%). The molecular weight of Intermediate 346-4 was about 944 as measured by FAB MS.
In an argon atmosphere, Intermediate 346-4 (5.26 g, 5.57 mmol), 7H-benzo[c]carbazole (2.33 g, 13.93 mmol), Pd(dba)2 (0.32 g, 0.56 mmol), (tBu)3PHBF4 (0.32 g, 1.11 mmol), and tBuONa (1.23 g, 12.82 mmol) were added to 27 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Compound 346 (2.38 g, yield 71%). The molecular weight of Compound 346 was about 1205 as measured by FAB MS.
Sublimation purification was performed (320° C., 3.3×10−3 Pa) to perform device evaluation.
Compound 347 according to an example may be synthesized, for example, by the reaction below:
In an argon atmosphere, 1,3-dibromo-5-(tert-butyl)benzene (5.68 g, 19.45 mmol), 2,4-dibutyldibenzo[b,d]thiophen-3-amine (6.36 g, 20.42 mmol), Pd(dba)2 (1.12 g, 1.95 mmol), (tBu)3PHBF4 (1.13 g, 3.89 mmol), and tBuONa (4.3 g, 44.74 mmol) were added to 97 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 347-1 (5.29 g, yield 52%). The molecular weight of Intermediate 347-1 was about 523 as measured by FAB MS.
In an argon atmosphere, Intermediate 347-1 (5.07 g, 9.7 mmol), 5′-(tert-butyl)-[1,1′:3′,1″-terphenyl]-2′-amine (3.8 g, 12.61 mmol), Pd(dba) (0.56 g, 0.97 mmol), (tBu)3PHBF4 (0.56 g, 1.94 mmol), and tBuONa (2.14 g, 22.31 mmol) were added to 48 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 347-2 (5.98 g, yield 83%). The molecular weight of Intermediate 347-2 was about 743 as measured by FAB MS.
A small amount of toluene (about 10 mL) was added to Intermediate 347-2 (5.88 g, 7.91 mmol), 1-chloro-3-iodobenzene (28.3 g, 118.69 mmol), CuI (3.16 g, 16.62 mmol), and K2CO3 (8.75 g, 63.3 mmol), and the resultant mixture was heated for about 24 hours while maintaining the temperature at about 215° C. The mixture was diluted with CH2Cl2, water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 347-3 (6.41 g, yield 84%). The molecular weight of Intermediate 347-3 was about 964 as measured by FAB MS.
In an argon atmosphere, Intermediate 347-3 (6.35 g, 6.59 mmol) was dissolved in ODCB (66 mL), BBr3 (4.12 g, 16.46 mmol) was added thereto, and the resultant mixture was heated and stirred at about 170° C. for about 10 hours. The resultant mixture was cooled to room temperature, DIPEA (10.19 g, 79.03 mmol) was added thereto, water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Intermediate 347-4 (3.33 g, yield 52%). The molecular weight of Intermediate 347-4 was about 972 as measured by FAB MS.
In an argon atmosphere, Intermediate 347-4 (5.26 g, 5.41 mmol), 7H-benzo[c]carbazole (2.26 g, 13.53 mmol), Pd(dba)2 (0.31 g, 0.54 mmol), (tBu)3PHBF4 (0.31 g, 1.08 mmol), and tBuONa (1.2 g, 12.45 mmol) were added to 27 mL of toluene, and the resultant mixture was heated and stirred at about 100° C. for about 8 hours. Water was added thereto, and the resultant mixture was subjected to celite filtering and liquid separation to concentrate an organic layer. The concentrated organic layer was purified by silica gel column chromatography to obtain Compound 347 (2.6 g, yield 78%). The molecular weight of Compound 347 was about 1233 as measured by FAB MS.
Sublimation purification was performed (320° C., 3.3×10−3 Pa) to perform device evaluation.
The light emitting element according to an Example including a fused polycyclic compound according to an Example in an emission layer was manufactured as follows. Compounds 5, 249, 285, 344, 346, and 347, which are Example Compounds as described above, were used as dopant materials for the emission layers to manufacture the light emitting elements of Examples 1 to 6. Comparative Examples 1 to 12 correspond to the light emitting elements manufactured by using Comparative Example Compounds X1 to X12 as dopant materials for the emission layers, respectively.
ITO was used to form a 150 nm-thick first electrode; dipyrazino[2,3-f: 2′,3′-h]quinoxaline-2,3,6,7, 10,11-hexacarbonitrile (HATCN) was used to form a 10 nm-thick hole injection layer on the first electrode; N,N′-di(1-naphthyl)-N,N′-diphenyl-(1,1″-biphenyl)-4,4″-diamine (NPD) was used to form a 80 nm-thick hole transport layer on the hole injection layer; 1,3-bis(N-carbazolyl)benzene (mCP) was used to form a 5 nm-thick emission-auxiliary layer on the hole transport layer; an Example Compound or a Comparative Example Compound was doped at a concentration of 1% in 3,3′-di(9H-carbazol-9-yl)-1,1′-biphenyl(mCBP) to form a 20 nm-thick emission layer on the emission-auxiliary layer; 2,2′,2″-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) was used to form a 30 nm-thick electron transport layer on the emission layer; LiF was used to form a 0.5 nm-thick electron injection layer on the electron transport layer; and Al was used to form a 100 nm-thick second electrode on the electron injection layer. Each layer was formed by a deposition method in a vacuum atmosphere.
Compounds used for manufacturing the light emitting elements of Examples and Comparative Examples are disclosed below. The compounds below are materials of the related art, and commercial products were subjected to sublimation purification and used to manufacture the devices.
Evaluation results of the light emitting elements in Examples 1 to 6 and Comparative Examples 1 to 12 are listed in Table 1. A maximum emission wavelength (λmax), roll-off, and a relative service life (LT50) of the manufactured light emitting elements are listed for comparison in Table 1.
In the characteristic evaluation results of Examples and Comparative Examples listed in Table 1, the roll-off is represented by [[(external quantum efficiency at 1 cd/m3)−(1,000 cd/m3)]/(external quantum efficiency at 1 cd/m3)]×100. The relative service life is shown by evaluating a brightness half-life from an initial brightness of 100 cd/m2. The relative service life is shown as a relative value in comparison to the service life Comparative Example 3.
Referring to the results of Table 1, it may be confirmed that the Examples, in which the fused polycyclic compounds according to embodiments are used as a luminescent material, have improved service life characteristics as compared with the Comparative Examples. The Example Compounds each include the fused ring core in which five rings are fused around the boron atom, the nitrogen atom, and the heteroatom, and including the first substituent linked to the nitrogen atom of the fused ring core, thereby achieving long service life. The Example Compounds exhibit excellent molecular stability due to the inclusion and structure of the first substituent, and thus may contribute to a long service life of the light emitting element ED. The first substituent may have a structure in which an alkyl group having at least four carbon atoms is substituted at an ortho position to the nitrogen atom of the fused ring core. Thus, by disposing an alkyl group having a long molecular field at an ortho position to the nitrogen atom an effective intermolecular distance may be achieved. HOMO and LUMO energy distribution may be suppressed by the alkyl group of the first substituent, thereby preventing unnecessary interaction with other molecules. Accordingly, the Example Compounds have a structure having high electron density in the fused ring core, and a reactive portion of the fused ring core is effectively protected, so that the molecular stability of the compound may be improved.
All of the emission wavelengths of Examples 1 to 6 exhibited a color purity close to pure blue near 460 nm, and all of Examples 1 to 6 exhibited relatively long service lives compared to the LT50 of Comparative Examples 1 to 12.
In Example 1, Example 4, and Example 6, the relative service lives were 2.8, 4.7, and 4.3, respectively, and thus each service life thereof was increased as compared to Comparative Example 3. It is believed that the service life-improving effect is obtained by introducing a linear alkyl sub-substituent of the first substituent at each of two ortho positions to the nitrogen atom as indicated by the following arrows.
Although Comparative Example 5 and Comparative Examples 7 to 9 are compounds in which an alkyl group is substituted, the relative service lives thereof were extremely low, ranging from 0.07 to 0.12. As shown in the following figures, it is considered that Comparative Compounds X5, X7, X8, and X9 each have a structure in which an alkyl group is substituted to a phenyl group linked to the nitrogen atom, but it is difficult to secure a molecular distance due to fused-cyclization of the alkyl group to the phenyl group, and thus service life characteristics are deteriorated compared to Examples when applied to the light emitting elements.
The service life-improving effect of the Example Compounds may be explained through a three-dimensional molecular model of Compound 607 below.
In comparing Example 1 with Example 4, it may be seen that the relative service life of Example 4 was 4.7, which was increased compared to the relative service life of Example 1, which was 2.8. Therefore, it may be seen that the molecular stability effect may depend on the number of carbon atoms of the alkyl group, and the above-described molecular stability effect increases as the molecular field increases.
In Example 2 and Example 5, the relative service lives were 3.1 and 3.2, respectively, and thus each service life thereof was increased as compared to Comparative Example 3. As shown in the figures below, Compounds 249 and 346 each have only one alkyl group, but have a relatively long relative service life. It is believed that even if only one alkyl group is introduced, the first ring has a structure that is fused to the benzene ring, and thus the molecular stability effect is secured to a similar degree compared to the case where two alkyl groups are introduced, thereby improving the service life.
However, there are Comparative Example Compounds X4, X6, and X10 in which one alkyl group is substituted, but the relative service lives thereof were very low, ranging from 0.05 to 0.15. Comparative Example Compound X10 has a structure in which a linear alkyl group is introduced to an ortho-position to the nitrogen atom, but the n-propyl group has a molecular field that is shorter than that of a benzene ring, and thus, since the effect of protecting the fused ring core is reduced, the compound has not exhibited a sufficient service life.
Comparative Compounds X11 and X12 are compounds having an alkyl group at a molecular terminal position, but the relative service lives thereof were low, which were 0.21 and 0.14, respectively. The service life deterioration of Comparative Example Compounds X11 and X12 may be explained through the figures below. The figures below show a structure of each of Compound 607 and Comparative Example Compounds X11 and X12 when viewed from above. Referring to the figures below, in the case of Compound 607, as the (1)alkyl group is linked at the ortho position of the phenyl group linked to the nitrogen atom, the alkyl group is disposed adjacent to the fused ring core, and thus may effectively protect the boron atom. Comparative Example Compound X11 is different from the Compound 607 in that an alkyl group is substituted at a dibenzofuran group linked to a phenyl group. In the case of Comparative Example Compound X11, since the (2)alkyl group is substituted at a relative end of the molecule, the distance to the core portion, which is the central skeleton, is significantly increased, and thus the effect of protecting the core as in the Example Compounds may be diminished. In the case of Comparative Example Compound X12, the (3)alkyl group is linked to a para position rather than an ortho position with respect to the nitrogen atom, and thus it is difficult to exhibit a sufficient steric hindrance effect compared with Example Compounds, and accordingly, a property of protecting the fused ring core around the boron atom may be insufficient. In contrast, the Example Compounds may exhibit excellent molecular stability due to the substituent structure of the alkyl group sub-substituent, and thus may contribute to long service life of the light emitting element.
The fused polycyclic compound according to an embodiment may be used in the emission layer to contribute to a long service life of the light emitting element The fused polycyclic compound according to an embodiment includes fused ring core having a boron atom, a nitrogen atom, and a heteroatom, and includes a structure in which the first substituent is bonded to the nitrogen atom of the fused ring core, there having high material stability. Thus, when the fused polycyclic compound according to an embodiment is included in an emission layer of the light emitting element, long service life may be achieved.
The light emitting element according to an embodiment may exhibit improved element characteristics with a long service life.
The fused polycyclic compound according to an embodiment may be included in the emission layer of the light emitting element to contribute to long service life of the light emitting element.
The display device according to an embodiment may exhibit excellent display quality.
Embodiments have been disclosed herein, and although terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for the purposes of limitation. In some instances, as would be apparent to one of ordinary skill in the art, features, characteristics, and/or elements described in connection with an embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope of the disclosure as set forth in the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2023-0117978 | Sep 2023 | KR | national |
