Patent Application
20250107440
This application claims priority to and benefits of Korean Patent Application No. 10-2023-0129446 under 35 U.S.C. § 119, filed on Sep. 26, 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 as an image display. In contrast to a liquid crystal display, the organic electroluminescence display is a so-called self-luminescent display in which holes and electrons respectively injected from a first electrode and a second electrode recombine in an emission layer, so that a light emitting material including an organic compound in the emission layer emits light to achieve display.
In the application of an organic electroluminescence device to a display device, there is a demand for an organic electroluminescence device having a lower driving voltage, increased emission efficiency, and a longer service life, and continuous development is required on materials for an organic electroluminescence device that are capable of stably achieving such characteristics.
In order to implement an organic electroluminescence device with high efficiency, technologies pertaining to phosphorescence emission, which uses energy in a triplet state, or pertaining to fluorescence emission, which uses the generating phenomenon of singlet excitons by the collision of triplet excitons (triplet-triplet annihilation, TTA), are being developed. Development is presently directed to a thermally activated delayed fluorescence (TADF) material that uses 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 having improved emission efficiency and element lifetime.
The disclosure provides a fused polycyclic compound which is capable of improving the emission efficiency and element lifetime of a light emitting element.
The disclosure provides a display device having excellent display quality by including a light emitting element having improved emission efficiency and lifetime.
A light emitting element according to an embodiment 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:
In Formula 1, A1 to A5, Ra, and R1 to R7 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring; n1 may be an integer from 0 to 3; at least one of A1 to A5 may each independently be a group represented by Formula 2; one of Ar1 and Ar2 may be a group represented by Formula 3-1; and the remainder of Ar1 and Ar2 may be a group represented by Formula 3-2.
In Formula 2, Ara to Arc may each independently be a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms; and is a position connected with Formula 1.
In Formula 3-1 and Formula 3-2, R8 to R14 and Z1 to Z3 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring; a1 to a3 may each independently be an integer from 0 to 5; and —* is a position connected with Formula 1.
In an embodiment, the first compound may be represented by Formula 4-1 or Formula 4-2:
In Formula 4-1 and Formula 4-2, Ar1, Ar2, R1 to R7, Ra, A1 to A5, and n1 are the same as defined in Formula 1.
In an embodiment, the first compound may be represented by Formula 5:
In Formula 5, Ar1, Ar2, R1 to R7, Ra, n1, A1, A2, A4, A5, Ara, Arb, and Arc are the same as defined in Formula 1.
In an embodiment, the first compound may be represented by one of Formula 6-1 to Formula 6-3:
In Formula 6-1 to Formula 6-3, Z4 may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring; and a4 may be an integer from 0 to 5.
In Formula 6-1 to Formula 6-3, R1 to R14, Ra, A1 to A5, Z1 to Z3, n1, and a1 to a3 are the same as defined in Formula 1, Formula 3-1, and Formula 3-2.
In an embodiment, the first compound may be represented by Formula 7-1 or Formula 7-2:
In Formula 7-1 and Formula 7-2, Rb1 to Rb3 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring; m1 to m3 may each independently be an integer from 0 to 5; Z4 may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring; and a4 may be an integer from 0 to 5.
In Formula 7-1 and Formula 7-2, R1 to R13, Ra, A1, A2, A4, A5, Z1 to Z3, n1, and a1 to a3 are the same as defined in Formula 1, Formula 3-1, and Formula 3-2.
In an embodiment, R6 may be a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms; and R5 and R7 may each independently be a hydrogen atom or a deuterium atom.
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, Rb4 may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms; m4 may be an integer from 0 to 5; Z4 may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring; and a4 may be an integer from 0 to 5.
In Formula 8-1 and Formula 8-2, R1 to R5, R7 to R13, Ra, A1 to A5, Z1 to Z3, n1, and a1 to a3 are the same as defined in Formula 1, Formula 3-1, and Formula 3-2.
In an embodiment, the first compound may be represented by Formula 9-1 or Formula 9-2:
In Formula 9-1 and Formula 9-2, R2a and R3a may each independently be a substituted or unsubstituted alkyl group of 1 to 10 carbon atoms, or a group represented by Formula A-i 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 cyano group, a nitro group, a hydroxyl group, a substituted or unsubstituted silyl group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thio group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring; m11 may be an integer from 0 to 5; and m12 and m13 may each independently be an integer from 0 to 4.
In Formula 9-1 and Formula 9-2, Ar1, Ar2, R1 to R7, A1 to A5, Ra, and n1 are the same as defined in Formula 1.
In an embodiment, in Formula 1, Ar1 and Ar2 may each independently be a group selected from Substituent Group 1:
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 of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group of 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 of 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms; and 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 of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms, or combined with 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 of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms; b1 to b3 may each independently be an integer from 0 to 10; Are to Ard may each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms; and L2 to L4 may each independently be a direct linkage, a substituted or unsubstituted arylene group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group of 2 to 30 ring-forming carbon atoms.
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 of 5 to 30 ring-forming carbon atoms or a substituted or unsubstituted heterocycle of 2 to 30 ring-forming carbon atoms; L11 to L13 may each independently be a direct linkage,
a substituted or unsubstituted alkylene group of 1 to 20 carbon atoms, a substituted or unsubstituted arylene group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group of 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 of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms; and d1 to d4 may each independently be an integer from 0 to 4.
A display device according to an embodiment 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
In an embodiment, the light emitting element may include multiple emission layers; and at least one of the emission layers may include the first compound.
In an embodiment, the display device may further include a light controlling layer disposed on the display element layer and including a quantum dot; wherein the light emitting element may emit first color light; and the light controlling layer may include a first light controlling part including a first quantum dot that converts the first color light into second color light which is in a longer wavelength region than the first color light, a second light controlling part including a second quantum dot that converts the first color light into third color light which is in a longer wavelength region than the first color light and the second color light, and a third light controlling part that transmits the first color light.
In an embodiment, the display device may further include a color filter layer disposed on the light controlling layer; 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.
A fused polycyclic compound according to an embodiment may be represented by Formula 1, which is explained herein.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 4-1 or Formula 4-2, which are explained herein.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 7-1 or Formula 7-2, which are explained herein.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 8-1 or Formula 8-2, which are explained herein.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 9-1 or Formula 9-2, 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 “combined with 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 combined with 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 to 40, 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
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 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 the 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 stater 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]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 the 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 description, 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 together, wherein the fused ring core includes a boron atom, two nitrogen atoms, and an aryl group. In an embodiment, the fused ring core of the fused polycyclic compound may have five rings in which three substituted or unsubstituted benzene rings are connected to each other via the boron atom and the two nitrogen atoms. In the fused ring core, the three benzene rings are connected to each other with the boron atom as a central atom, and among the three benzene rings, a first benzene ring and a second benzene ring are connected to each other via one of the nitrogen atoms, and a third benzene ring may be connected to the second benzene ring via the other nitrogen atom. The boron atom and that two nitrogen atoms may all be connected to the second benzene ring.
The aryl group included in the fused polycyclic compound may be connected with the first benzene ring. The aryl group may be directly connected to the first benzene ring without a separate linking moiety. The aryl group may be a monocyclic or polycyclic aromatic hydrocarbon ring. For example, the aryl group may be a six-member monocyclic aromatic hydrocarbon ring. In the specification, the first benzene ring of the fused ring core and the aryl group connected with the first benzene ring may be referred to as a “diaryl part”.
The fused polycyclic compound according to an embodiment may include a silyl group as a substituent. The silyl group may be substituted with a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. The silyl group may be connected with the fused ring core via the aryl group.
The fused polycyclic compound according to an embodiment may include a first substituent and a second substituent, which are steric hindrance substituents in a molecular structure. The first substituent and the second substituent may each be connected with the nitrogen atoms of the fused ring core. The first substituent may be connected with one of the nitrogen atoms of the fused ring core, and the second substituent may be connected with the remaining nitrogen atom. The first substituent may include a benzene moiety, a first sub-substituent, and a second sub-substituent, which are substituted at carbon atoms at specific positions of the benzene moiety. The first substituent may be connected with a nitrogen atom of the fused ring core, and may include the first sub-substituent and the second sub-substituent each connected at an ortho position with respect to the nitrogen atom. The first sub-substituent and the second sub-substituent may each independently be a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms. The second substituent may include a benzene moiety and a third sub-substituent which is substituted at a carbon atom at a specific position of the benzene moiety. The second substituent may be connected with the remaining nitrogen atom of the fused ring core, and may have a structure in which the third sub-substituent is connected at an ortho position with respect to the remaining nitrogen atom. The third sub-substituent may be a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms
The fused polycyclic compound according to an embodiment may be represented by Formula 1:
The fused polycyclic compound according to an embodiment, represented by Formula 1, may include a fused ring core that is formed by fusing five rings with a boron atom, a first nitrogen atom, and a second nitrogen atom, and an aryl group connected with the fused ring core. The fused polycyclic compound may include a silyl group connected with the fused ring core via the aryl group. In the specification, in Formula 1, a benzene ring that includes a substituent represented by Ra may correspond to the first benzene ring, a benzene ring that includes substituents represented by R1 to R4 may correspond to the third benzene ring, and a benzene ring that includes substituents represented by R5 to R7 may correspond to the second benzene ring. In Formula 1, a benzene ring that includes substituents represented by A1 to A5 may correspond to the aryl group.
In Formula 1, A1 to A5, Ra, and R1 to R7 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring. For example, A1 to A5 may each independently be a hydrogen atom or a substituted or unsubstituted silyl group; Ra may be a hydrogen atom; and R1 to R7 may each independently be a hydrogen atom, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbazole group.
In an embodiment, R6 may be a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms; and R5 and R7 may each independently be a hydrogen atom or a deuterium atom. For example, R6 may be a substituted or unsubstituted t-butyl group or a substituted or unsubstituted phenyl group, and R5 and R7 may each be a hydrogen atom.
In Formula 1, n1 may be an integer from 0 to 3. If n1 is 0, the fused polycyclic compound may not be substituted with Ra. A case where n1 is 3 and three Ra groups are all hydrogen atoms may be the same as a case where n1 is 0. If n1 is 2 or more, multiple Ra groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 1, at least one of A1 to A5 may each independently be a group represented by Formula 2. In an embodiment, one of A1 to A5 may be a group represented by Formula 2, and the remainder of A1 to A5 may each independently be hydrogen atoms or deuterium atoms. For example, A3 may be a group represented by Formula 2; and A1, A2, A4, and A5 may each independently be a hydrogen atom or a deuterium atom.
In Formula 1, one of Ar1 and Ar2 may be a group represented by Formula 3-1; and the remainder of Ar1 and Ar2 may be a group represented by Formula 3-2.
In Formula 2, Ara to Arc may each independently be a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms. For example, Ara to Arc may each independently be a substituted or unsubstituted phenyl group.
In Formula 2, is a position connected with Formula 1.
In Formula 3-1 and Formula 3-2, R8 to R14 and Z1 to Z3 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring. For example, R8 to R14 may each independently be a hydrogen atom, a substituted or unsubstituted methyl group, a deuterated methyl group, a substituted or unsubstituted isopropyl group, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group; and Z1 to Z3 may each independently be a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group. In the specification, the term “deuterated methyl group” may be interpreted such that at least one hydrogen atom of the methyl group may be substituted with a deuterium atom. In a deuterated methyl group, the methyl group may be mono-substituted, di-substituted, or completely substituted with deuterium.
In Formula 3-1 and Formula 3-2, a1 to a3 may each independently be an integer from 0 to 5. If a1 to a3 are each 0, the fused polycyclic compound may not be substituted with Z1 to Z3, respectively. A case where a1 to a3 are each 5 and five groups of each of Z1 to Z3 are all hydrogen atoms may be the same as a case where a1 to a3 are each 0. If a1 to a3 are each 2 or more, multiple groups of each of Z1 to Z3 may all be the same, or at least one thereof may be different from the remainder.
In Formula 3-1 and Formula 3-2, —* is a position connected with Formula 1.
In an embodiment, the group represented by Formula 3-2 may be represented by Formula 3-2-a.
In Formula 3-2-a, Z4 may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring. For example, Z4 may be a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.
In Formula 3-2-a, a4 may be an integer from 0 to 5. If a4 is 0, the fused polycyclic compound may not be substituted with Z4. A case where a4 is 5 and five Z4 groups are all hydrogen atoms may be the same as a case where a4 is 0. If a4 is 2 or more, multiple Z4 groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 3-2-a, Z3, a3, and R1 to R13 are the same as defined in Formula 3-2.
The fused polycyclic compound according to an embodiment includes a structure in which an aryl group is connected with the fused ring core, and may show improved thermally activated delayed fluorescence properties.
A compound showing thermally activated delayed fluorescence properties undergoes inter system crossing (ICS), which is the transition of energy from a lowest singlet energy level to a lowest excited triplet energy level, and then undergoes reverse inter system crossing (RISC), which is the transition from the lowest excited triplet energy level to the lowest excited singlet energy level, and then undergoes delayed fluorescence through the transition from the lowest excited singlet energy level to a ground state. The mechanism of thermally activated delayed fluorescence may also include the transition of energy of a higher triplet energy level (Tn level) in the inter system crossing (ICS) and the reverse inter system crossing (RISC) processes.
In a light emitting element that uses thermally activated delayed fluorescence emission, an important factor that indicates low efficiency and short lifetime is a low reverse inter system crossing rate in a thermally activated delayed fluorescence (TADF)-based emitter. According to the El-sayed rule, the spin-orbit coupling constant between a lowest excited singlet energy level (Si) and a lowest excited triplet energy level (T1) is near 0, and direct transition between the lowest excited singlet energy level (S1) and the lowest excited triplet energy level (T1) may not readily occur, and thus, a complicated inter system crossing mechanism involving the transition of a higher excited triplet energy level (Tn level, where n is 2 or more) is used. Under such conditions, exciton quenching such as accumulated triplet exciton collision may occur, and thus may result in the deterioration of efficiency and lifetime of an organic light emitting element. Accordingly, if triplet excitons of high energy, which are accumulated in an emitter, transition at a fast rate, both emission efficiency and lifetime may be improved.
According to embodiments, an increase in the rate of reverse inter system crossing of the fused polycyclic compound may be achieved by a local excited triplet energy level (3LE) that is localized in the “diaryl part”. In the fused polycyclic compound according to an embodiment, the local excited triplet energy level (3LE) in the “diaryl part” may be formed between a lowest excited triplet energy level (T1) and a second excited triplet energy level (T2). Accordingly, reverse inter system crossing (RISC) between the lowest excited triplet energy level (T1) and a lowest excited singlet energy level (S1) may be mediated by the local excited triplet energy level (3LE) to increase the rate of reverse inter system crossing. For example, if the local excited triplet energy level (3LE) is positioned between the lowest excited triplet energy level (T1) and the second excited triplet energy level (T2), exciton energy may transition rapidly through a pass of T1→3LE→S1, and accordingly, the rate of reverse inter system crossing may increase to improve emission efficiency.
In the fused polycyclic compound according to an embodiment, the spin-orbit coupling constant between the local excited triplet energy level (3LE) in the “diaryl part” and the lowest singlet energy level (S1) may be greater than the spin-orbit coupling constant between the lowest excited triplet energy level (T1) and the lowest singlet energy level (Si). Since a transition probability between the triplet state and the singlet state is dependent on the strength of spin orbital interaction, the fused polycyclic compound having an improved spin-orbit coupling constant may have an improved rate of reverse inter system crossing.
The fused polycyclic compound according to an embodiment includes a silyl group as a substituent. The silyl group may be connected with the fused ring core via the aryl group. The fused polycyclic compound includes a silyl group having large bulkiness to increase intermolecular distance, to prevent Dexter energy transfer, and to improve element performance. In a molecule, an orbital may not expand in the silyl group, and optical properties such as absorption wavelength, and emission wavelength may not be influenced. Accordingly, it may be possible to improve emission efficiency and lifetime characteristics, while maintaining excellent optical properties of the molecule itself. The silyl group has good thermal stability in comparison to other substituents and may contribute to the improvement of stability of a material.
The fused polycyclic compound according to an embodiment may effectively maintain a trigonal planar structure of the boron atom through steric hindrance effects by the first substituent and the second substituent. Since the boron atom has electron-deficient properties due to a vacant p-orbital, a bond may be formed with another nucleophile to change the trigonal planar structure into a tetrahedral structure, which may contribute to the deterioration of a light emitting element. According to embodiments, the fused polycyclic compound represented by Formula 1 includes the first substituent and the second substituent in a fused ring core, and the vacant p-orbital of the boron atom may be effectively protected, and thus, deterioration due to molecular structural deformation may be prevented.
In the fused polycyclic compound according to an embodiment, intermolecular interaction is suppressed through steric hindrance effects by the first substituent and the second substituent, and the formation of aggregates, excimers, and exciplexes may be controlled, and accordingly, emission efficiency may be improved. Since the fused polycyclic compound has a bulky structure, intermolecular distance may be increased to reduce Dexter energy transfer, and accordingly, an increase of the concentration of triplet excitons in the fused polycyclic compound may be suppressed. Since triplet excitons at a high concentration may stay in an excited state for a long time, decomposition of a compound may be induced, the production of hot excitons having high energy through triplet-triplet annihilation (TTA) may be induced, and the cleavage of an adjacent compound structure may be induced. Triplet-triplet annihilation is a bimolecular reaction, and rapidly exhausts triplet excitons used for emitting light, and accordingly, the deterioration of emission efficiency may be induced by non-radiative transition. Since intermolecular distance may increase due to the first and second substituents in the fused polycyclic compound, Dexter energy transfer may be suppressed, and the deterioration of device lifetime that is generated by an increase of triplet concentration may be suppressed. Accordingly, if the fused polycyclic compound is applied to an emission layer EML of a light emitting element ED, emission efficiency may be improved, and element lifetime may also be increased.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 4-1 or Formula 4-2.
In Formula 4-1 and Formula 4-2, Ar1, Ar2, R1 to R7, Ra, A1 to A5, and n1 are the same as defined in Formula 1.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 5.
Formula 5 represents a case where the bonding position of the group represented by Formula 2 to Formula 1 is further defined.
In Formula 5, Ar1, Ar2, R1 to R7, Ra, n1, A1, A2, A4, A5, Ara, Arb, and Arc are the same as defined in Formula 1 and Formula 2.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by one of Formula 6-1 to Formula 6-3.
In Formula 6-3, Z4 may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring. For example, Z4 may be a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.
In Formula 6-3, a4 may be an integer from 0 to 5. If a4 is 0, the fused polycyclic compound may not be substituted with Z4. A case where a4 is 5 and five Z4 groups are all hydrogen atoms may be the same as a case where a4 is 0. If a4 is 2 or more, multiple Z4 groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 6-1 to Formula 6-3, R1 to R14, Ra, A1 to A5, Z1 to Z3, n1, and a1 to a3 are the same as defined in Formula 1, Formula 3-1, and Formula 3-2.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 7-1 or Formula 7-2.
In Formula 7-1 and Formula 7-2, Rb1 to Rb3 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring. For example, Rb1 to Rb3 may each be a hydrogen atom.
In Formula 7-1 and Formula 7-2, m1 to m3 may each independently be an integer from 0 to 5. If m1 to m3 are each 0, the fused polycyclic compound may not be substituted with Rb1 to Rb3, respectively. A case where m1 to m3 are each 5 and five group of each of Rb1 to Rb3 are all hydrogen atoms may be the same as a case where m1 to m3 are each 0. If m1 to m3 are each 2 or more, multiple groups of each of Rb1 to Rb3 may all be the same, or at least one thereof may be different from the remainder.
In Formula 7-1 and Formula 7-2, Z4 may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring. For example, Z4 may be a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.
In Formula 7-1 and Formula 7-2, a4 may be an integer from 0 to 5. If a4 is 0, the fused polycyclic compound may not be substituted with Z4. A case where a4 is 5 and five Z4 groups are all hydrogen atoms may be the same as a case where a4 is 0. If a4 is 2 or more, multiple Z4 groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 7-1 and Formula 7-2, R1 to R13, Ra, A1, A2, A4, A5, Z1 to Z3, n1, and a1 to a3 are the same as defined in Formula 1, Formula 3-1, and Formula 3-2.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 8-1 or Formula 8-2.
In Formula 8-2, Rb4 may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms. For example, Rb4 may be a hydrogen atom or a substituted or unsubstituted t-butyl group.
In Formula 8-2, m4 may be an integer from 0 to 5. If m4 is 0, the fused polycyclic compound may not be substituted with Rb4. A case where m4 is 5 and five Rb4 groups are all hydrogen atoms may be the same as a case where m4 is 0. If m4 is 2 or more, multiple Rb4 groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 8-1 and Formula 8-2, Z4 may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring. For example, Z4 may be a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.
In Formula 8-1 and Formula 8-2, a4 may be an integer from 0 to 5. If a4 is 0, the fused polycyclic compound may not be substituted with Z4. A case where a4 is 5 and five Z4 groups are all hydrogen atoms may be the same as a case where a4 is 0. If a4 is 2 or more, multiple Z4 groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 8-1 and Formula 8-2, R1 to R5, R7 to R13, Ra, A1 to A5, Z1 to Z3, n1, and a1 to a3 are the same as defined in Formula 1, Formula 3-1, and Formula 3-2.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by Formula 9-1 or Formula 9-2.
In Formula 9-1 and Formula 9-2, R2a and R3a may each independently be a substituted or unsubstituted alkyl group of 1 to 10 carbon atoms, or a group represented by Formula A-1 or Formula A-2. In an embodiment, R2a and R3a may each independently be a substituted or unsubstituted t-butyl group or 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 cyano group, a nitro group, a hydroxyl group, a substituted or unsubstituted silyl group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thio group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring. For example, Rc1 to Rc3 may each independently be a hydrogen atom, a deuterium atom, a deuterated methyl group, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.
In Formula A-1, m11 may be an integer from 0 to 5. If m11 is 0, the fused polycyclic compound may not be substituted with Rc1. A case where m11 is 5 and five Rc1 groups are all hydrogen atoms may be the same as a case where m11 is 0. If m11 is 2 or more, multiple Rc1 groups may all be the same, or at least one thereof may be different from the remainder.
In Formula A-2, m12 and m13 may each independently be an integer from 0 to 4. If m12 and m13 are each 0, the fused polycyclic compound may not be substituted with Rc2 and Rc3, respectively. A case where m12 and m13 are each 4 and multiple groups of each of Rc2 and Rc3 are all hydrogen atoms may be the same as a case where m12 and m13 are each 0. If m12 and m13 are each 2 or more, multiple Rc2 groups and multiple Rc3 groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 9-1 and Formula 9-2, Ar1, Ar2, R1 to R7, A1 to A5, Ra, and n1 are the same as defined in Formula 1.
In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by one of Formula 10-1 to Formula 10-3.
In Formula 10-1 to Formula 10-3, Rd1 to Rd4 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a hydroxyl group, a substituted or unsubstituted silyl group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thio group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring. For example, Rd1 to Rd4 may each independently be a hydrogen atom, a deuterium atom, a deuterated methyl group, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.
In Formula 10-1, m21 and m22 may each independently be an integer from 0 to 4. If m21 and m22 are each 0, the fused polycyclic compound may not be substituted with Rd1 and Rd2, respectively. A case where m21 and m22 are each 4 and four Rd1 groups and four Rd2 groups are all hydrogen atoms may be the same as a case where m21 and m22 are each 0. If m21 and m22 are each 2 or more, multiple Rd1 groups and multiple Rd2 groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 10-2 and Formula 10-3, m23 and m24 may each independently be an integer from 0 to 5. If m23 and m24 are each 0, the fused polycyclic compound may not be substituted with Rd3 and Rd4, respectively. A case where m23 and m24 are each 5 and five Rd3 groups and five Rd4 groups are all hydrogen atoms may be the same as a case where m23 and m24 are each 0. If m23 and m24 are each 2 or more, multiple Rd3 groups and multiple Rd4 groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 10-1 to Formula 10-3, Z4 may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring. For example, Z4 may be a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.
In Formula 10-1 to Formula 10-3, a4 may be an integer from 0 to 5. If a4 is 0, the fused polycyclic compound may not be substituted with Z4. A case where a4 is 5 and five Z4 groups are all hydrogen atoms may be the same as a case where a4 is 0. If a4 is 2 or more, multiple Z4 groups may all be the same, or at least one thereof may be different from the remainder.
In Formula 10-1 to Formula 10-3, R1 to R13, A1 to A5, Ra, n1, Z1 to Z3, and a1 to a3 are the same as defined in Formula 1, Formula 3-1, and Formula 3-2.
In an embodiment, in Formula 1, Ar1 and Ar2 may each independently be a group selected from Substituent Group 1.
In an embodiment, the fused polycyclic compound represented by Formula 1 may include at least one deuterium atom as a substituent. The fused polycyclic compound represented by Formula 1 according to an embodiment may have a structure in which at least one hydrogen atom is 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.
An emission spectrum of the fused polycyclic compound represented by Formula 1 may have a full width at half maximum (FWHM) in a range of about 10 nm to 50 nm. For example, an emission spectrum of the fused polycyclic compound represented by Formula 1 may have a FWHM in a range of about 20 nm to 40 nm. Since an emission spectrum of the fused polycyclic compound represented by Formula 1 has the above-described range of the full width at half maximum, emission efficiency of a light emitting element may be improved when the light emitting element includes the fused polycyclic compound. If the fused polycyclic compound is used as a material of a blue light emitting element, element lifetime may be improved.
In an embodiment, the fused polycyclic compound according to an embodiment may be a material for emitting thermally activated delayed fluorescence. In an embodiment, the fused polycyclic compound may be a thermally activated delayed fluorescence dopant having a difference (ΔEST) between a lowest triplet excitation energy level (T1) and a lowest singlet excitation 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 excitation energy level (T1) and a lowest singlet excitation 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 a first substituent and a second substituent as described above. By adjusting the substituents and their respective bonding positions for the first substituent and the second substituent, a singlet energy level and a triplet energy level may be appropriately controlled in the overall fused polycyclic compound. Accordingly, the fused polycyclic compound according to an embodiment may exhibit improved thermally activated delayed fluorescence properties.
The fused polycyclic compound may be a light-emitting 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 if the fused polycyclic compound is used as a light emitting 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 in an emission layer EML as a dopant material. 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 at least one fused polycyclic compound selected from Compound Group 1 as a thermally delayed fluorescence dopant. 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 of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group of 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 of 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group of 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 of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms, or combined with 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, at least two of Za to Zc may each be N, and the remainder of Za to Zc 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 of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 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 of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 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 of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group of 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 of 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroarylene group of 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 the 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 of 5 to 30 ring-forming carbon atoms or a substituted or unsubstituted heterocycle of 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 of 1 to 20 carbon atoms, a substituted or unsubstituted arylene group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group of 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 of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms, or combined with 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, d1 to d4 may each independently be an integer from 0 to 4. If d1 to d4 are each 0, the fourth compound may not be substituted with R61 to R64, respectively. A case where d1 to d4 are each 4 and four groups of each of R61 to R64 are all hydrogen atoms may be the same as a case where d1 to d4 are each 0. If d1 to d4 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 C—* or C(R74), P2 may be N—* or N(R81), P3 may be N—* or N(R82), and P4 may be C—* or C(R88).
In Formula C-1 to Formula C-4, R71 to R88 may each independently be a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with 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 of 1 to 10 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 10 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with 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 of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group of 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 of 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroarylene group of 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 of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with 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 A1 to A5 may each be N, and the remainder of A1 to A5 may each independently be C(R1).
In Formula E-2b, Cbz1 and Cbz2 may each independently be an unsubstituted carbazole group, or a carbazole group substituted with an aryl group of 6 to 30 ring-forming carbon atoms. In Formula E-2b, Le may be a direct linkage, a substituted or unsubstituted arylene group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group of 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 Le groups may each independently be a substituted or unsubstituted arylene group of 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroarylene group of 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 of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with 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 is 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-a1 to M-a25. However, Compounds M-a1 to M-a25 are only examples, and the compound represented by Formula M-a is not limited to Compounds M-a1 to M-a25.
In an embodiment, the emission layer EML may further include a compound by represented 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 selected of Ra to Rj may each independently be substituted with a group represented by *—NAr1A2. The remainder of Ra to Rj which are not substituted with the group represented by *—NAr1A2 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 of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms.
In the group represented by *—NAr1A2, Ar1 and Ar2 may each independently be a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group of 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 of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring. In Formula F-b, Ar1 to Ar4 may each independently be a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group of 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 of 5 to 30 ring-forming carbon atoms or a substituted or unsubstituted heterocycle of 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 of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 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 of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring.
In Formula F-c, A1 and A2 may each independently be combined with a substituent of an adjacent ring to form a fused ring. For example, if A1 and A2 are each independently N(Rm), A1 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 by a similar process.
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 I-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; and 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 may 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 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 a 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 have a single layer structure or a multilayer structure. 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 in 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 of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 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 of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 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 of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group of 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 of 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroarylene group of 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 KI:Yb, RbI: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 (α-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 BR1, 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 to 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 as 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 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 herein. For example, in an embodiment, 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.
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 an apparatus that is activated by 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 device such as a camera.
In
At least one of the first to fourth display devices 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 with 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, which 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 the 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 described synthesis methods of Compounds 2, 3, 34, 66, 78, 83, 101, 107, 113, and 117. 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 2 according to an embodiment may be synthesized, for example, by the reaction below.
Under an argon atmosphere, to a 1 L flask, the compounds of 1,3-dibromo-5-(tert-butyl)benzene (2 eq), 5′-(tert-butyl)-[1,1′:3′,1″-terphenyl]-2′-amine (1 eq), pd2(dba)3 (0.05 eq), 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP, 0.1 eq), and sodium tert-butoxide (3 eq) were added and dissolved in toluene, and the reaction solution was stirred at about 100 degrees for about 12 hours. After cooling, water and ethyl acetate were added, extraction was performed, and organic layers were collected, dried over MgSO4, and filtered. The solvent of the filtrate solution was removed under a reduced pressure, and the solid thus obtained was purified and separated by column chromatography using CH2Cl2 and hexane as developing solvents to obtain Intermediate 2-a (yield: 65%). Through ESI-LCMS, the compound thus obtained was identified as Intermediate 2-a.
ESI-LCMS: [M]+: C32H34BrN. 511.1870.
Under an argon atmosphere, to a 1 L flask, Intermediate 2-a (1 eq), 1-chloro-3-iodobenzene (1.5 eq), copper iodide (1 eq), 1,10-phenanthroline (1 eq), and potassium carbonate (3 eq) were added and dissolved in N,N-dimethylformamide (DMF), and the reaction solution was stirred at about 160 degrees for about 12 hours. After cooling, water and ethyl acetate were added, extraction was performed, and organic layers were collected, dried over MgSO4, and filtered. The solvent of the filtrate solution was removed under a reduced pressure, and the solid thus obtained was purified and separated by column chromatography using CH2Cl2 and hexane as developing solvents to obtain Intermediate 2-b (yield: 42%). Through ESI-LCMS, the compound thus obtained was identified as Intermediate 2-b.
ESI-LCMS: [M]+: C38H37BrClN. 621.1798.
Under an argon atmosphere, to a 1 L flask, Intermediate 2-b (1 eq), 5′-(tert-butyl)-[1,1′:3′,1″-terphenyl]-2′-amine (1.1 eq), pd2(dba)3 (0.05 eq), tris-tert-butyl phosphine (0.1 eq), and sodium tert-butoxide (3 eq) were added and dissolved in toluene, and the reaction solution was stirred at about 110 degrees for about 12 hours. After cooling, water and ethyl acetate were added, extraction was performed, and organic layers were collected, dried over MgSO4, and filtered. The solvent of the filtrate solution was removed under a reduced pressure, and the solid thus obtained was purified and separated by column chromatography using CH2Cl2 and hexane as developing solvents to obtain Intermediate 2-c (yield: 72%). Through ESI-LCMS, the compound thus obtained was identified as Intermediate 2-c.
ESI-LCMS: [M]+: C60H59ClN2. 842.4360.
Under an argon atmosphere, to a 1 L flask, Intermediate 2-c (1 eq), iodobenzene (1.5 eq), copper iodide (1 eq), 1,10-phenanthroline (1 eq), and potassium carbonate (3 eq) were added and dissolved in DMF, and the reaction solution was stirred at about 160 degrees for about 12 hours. After cooling, water and ethyl acetate were added, extraction was performed, and organic layers were collected, dried over MgSO4, and filtered. The solvent of the filtrate solution was removed under a reduced pressure, and the solid thus obtained was purified and separated by column chromatography using CH2Cl2 and hexane as developing solvents to obtain Intermediate 2-d (yield: 53%). Through ESI-LCMS, the compound thus obtained was identified as Intermediate 2-d.
ESI-LCMS: [M]+: C66H63ClN2. 918.4680.
Under an argon atmosphere, to a 500 mL flask, Intermediate 2-d (1 eq) was added, dissolved in o-dichlorobenzene, and cooled using water-ice, and BBr3 (5 eq) was slowly added thereto dropwise, followed by stirring at about 180 degrees for about 12 hours. After cooling, triethylamine (5 eq) was added to quench the reaction, extraction was performed using water and CH2Cl2, and organic layers were collected, dried over MgSO4, and filtered. The solvent of the filtrate solution was removed under a reduced pressure, and the solid thus obtained was purified and separated by column chromatography using CH2Cl2 and hexane as developing solvents to obtain Intermediate 2-e (yellow solid, 23%). Through ESI-LCMS, the compound thus obtained was identified as Intermediate 2-e.
ESI-LCMS: [M]+: C66H60BClN2. 926.4538.
Under an argon atmosphere, to a 500 mL flask, Intermediate 2-e (1 eq) was added, dissolved in dichloromethane, and cooled using water-ice, and N-bromosuccinimide (MBS, 1 eq) was slowly added thereto dropwise, followed by stirring at room temperature for about 2 hours. Extraction was performed using water and CH2Cl2, and organic layers were collected, dried over MgSO4, and filtered. The solvent of the filtrate solution was removed under a reduced pressure, and the solid thus obtained was purified and separated by column chromatography using CH2Cl2 and hexane as developing solvents to obtain Intermediate 2-f (yield, 68%). Through ESI-LCMS, the compound thus obtained was identified as Intermediate 2-f.
ESI-LCMS: [M]+: C66H59BBrClN2. 1004.3640.
Under an argon atmosphere, to a 2 L flask, Intermediate 2-f (1 eq), (4-(triphenylsilyl)phenyl)boronic acid (1.2 eq), Pd(PPh3)4 (0.03 eq), and potassium carbonate (2 eq) were added and dissolved in toluene:ethyl alcohol:H2O (5:1:2), and the reaction solution was stirred at about 100 degrees for about 12 hours. After cooling, water (1 L) and ethyl acetate (300 mL) were added, extraction was performed, and organic layers were collected, dried over MgSO4, and filtered. The solvent of the filtrate solution was removed under a reduced pressure, and the solid thus obtained was purified and separated by column chromatography using CH2Cl2 and hexane as developing solvents to obtain Intermediate 2-g (yield: 70%). Through ESI-LCMS, the compound thus obtained was identified as Intermediate 2-g.
SI-LCMS: [M]+: C90H78BClN2Si. 1260.5716.
Under an argon atmosphere, to a 1 L flask, Intermediate 2-g (1 eq), 9H-carbazole-1,2,3,4,5,6,7,8-d8 (1.2 eq), Pd2(dba)3 (0.05 eq), tris-tert-butyl phosphine (0.1 eq), and sodium tert-butoxide (3 eq) were added and dissolved in o-xylene, and the reaction solution was stirred at about 140 degrees for about 12 hours. After cooling, water and ethyl acetate were added, extraction was performed, and organic layers were collected, dried over MgSO4, and filtered. The solvent of the filtrate solution was removed under a reduced pressure, and the solid thus obtained was purified and separated by column chromatography using CH2Cl2 and hexane as developing solvents to obtain Compound 2 (yield: 68%). Through 1H-NMR and ESI-LCMS, the compound thus obtained was identified as Compound 2.
1H-NMR (400 MHz, CDCl3): δ=9.15 (d, 1H), 9.12 (s, 1H), 7.89-7.80 (m, 4H), 7.75-7.65 (m, 4H), 7.43-7.40 (s, 4H), 7.38-7.28 (m, 15H), 7.20-7.12 (m, 12H), 7.08-6.99 (m, 8H), 6.20-6.18 (s, 2H), 1.41-1.39 (s, 18H), 1.35-1.32 (s, 9H).
ESI-LCMS: [M]+: C102H78D8BN3Si. 1399.7186.
Compound 3 according to an embodiment may be synthesized, for example, by the reaction below.
According to the same method for synthesizing Intermediate 2-a, Intermediate 3-a was synthesized using 5′-phenyl-[1,1′:3′,1″-terphenyl]-2′-amine instead of 5′-(tert-butyl)-[1,1′:3′,1″-terphenyl]-2′-amine (yield: 56%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 3-a.
ESI-LCMS: [M]+: C34H30BrN. 531.1562.
According to the same method for synthesizing Intermediate 2-b, Intermediate 3-b was synthesized using Intermediate 3-a instead of Intermediate 2-a (yield: 69%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 3-b.
ESI-LCMS: [M]+: C40H33BrClN. 641.1485.
According to the same method for synthesizing Intermediate 2-c, Intermediate 3-c was synthesized using Intermediate 3-b instead of Intermediate 2-b and using 5′-phenyl-[1,1′:3′,1″-terphenyl]-2′-amine instead of 5′-(tert-butyl)-[1,1′:3′,1″-terphenyl]-2′-amine (yield: 72%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 3-c.
ESI-LCMS: [M]+: C64H51ClN2. 882.3741.
According to the same method for synthesizing Intermediate 2-d, Intermediate 3-d was synthesized using Intermediate 3-c instead of Intermediate 2-c (yield: 71%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 3-d.
ESI-LCMS: [M]+: C70H55ClN2. 958.4054.
According to the same method for synthesizing Intermediate 2-e, Intermediate 3-e was synthesized using Intermediate 3-d instead of Intermediate 2-d (yield: 20%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 3-e.
ESI-LCMS: [M]+: C70H52BClN2. 966.3912.
According to the same method for synthesizing Intermediate 2-f, Intermediate 3-f was synthesized using Intermediate 3-e instead of Intermediate 2-e (yield: 51%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 3-f.
ESI-LCMS: [M]+: C70H51BBrClN2. 1044.3017.
According to the same method for synthesizing Intermediate 2-g, Intermediate 3-g was synthesized using Intermediate 3-f instead of Intermediate 2-f (yield: 68%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 3-g.
ESI-LCMS: [M]+: C94H70BClN2Si. 1300.5090.
According to the same method for synthesizing Compound 2, Compound 3 was synthesized using Intermediate 3-g instead of Intermediate 2-g (yellow solid, yield: 63%). Through 1H-NMR and ESI-LCMS, the yellow solid thus obtained was identified as Compound 3.
1H-NMR (400 MHz, CDCl3): d=9.14 (d, 1H), 9.11 (s, 1H), 7.85-7.80 (m, 4H), 7.72-7.68 (m, 4H), 7.44-7.43 (s, 4H), 7.40-7.25 (m, 15H), 7.20-7.12 (m, 12H), 7.10-7.02 (m, 8H), 7.00-6.88 (m, 10H), 6.19-6.18 (s, 2H), 1.35-1.32 (s, 9H).
ESI-LCMS: [M]+: C106H70D8BN3Si. 1439.6560.
Compound 34 according to an embodiment may be synthesized, for example, by the reaction below.
According to the same method for synthesizing Compound 2, Compound 34 was synthesized using 3,6-di-tert-butyl-9H-carbazole instead of 9H-carbazole-1,2,3,4,5,6,7,8-d8 (yellow solid, yield: 72%). Through 1H-NMR and ESI-LCMS, the yellow solid thus obtained was identified as Compound 34.
1H-NMR (400 MHz, CDCl3): δ=9.15 (d, 1H), 9.12 (s, 1H), 8.45-8.33 (m, 6H), 7.89-7.80 (m, 4H), 7.75-7.65 (m, 4H), 7.43-7.40 (s, 4H), 7.38-7.28 (m, 15H), 7.20-7.12 (m, 12H), 7.08-6.99 (m, 8H), 6.20-6.18 (s, 2H), 1.50-1.48 (s, 18H) 1.41-1.39 (s, 18H), 1.35-1.32 (s, 9H).
ESI-LCMS: [M]+: C110H102D8BN3Si. 1503.7685.
Compound 66 according to an embodiment may be synthesized, for example, by the reaction below.
Under an argon atmosphere, to a 2 L flask, 1,3-dibromo-5-iodobenzene (3 eq), phenylboronic acid (1.0 eq), Pd(PPh3)4 (0.03 eq), and potassium carbonate (2 eq) were added and dissolved in THF:H2O (3:1), and the reaction solution was stirred at about 70 degrees for about 6 hours. After cooling, water (1 L) and ethyl acetate (300 mL) were added, extraction was performed, and organic layers were collected, dried over MgSO4, and filtered. The solvent of the filtrate solution was removed under a reduced pressure, and the solid thus obtained was purified and separated by column chromatography using CH2Cl2 and hexane as developing solvents to obtain Intermediate 66-a (yield: 60%). Through ESI-LCMS, the compound thus obtained was identified as Intermediate 66-a.
SI-LCMS: [M]+: C12H8Br2. 310.8993.
According to the same method for synthesizing Intermediate 2-a, Intermediate 66-b was synthesized using Intermediate 66-a instead of 1,3-dibromo-5-(tert-butyl)benzene (yield: 68%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 66-b.
ESI-LCMS: [M]+: C34H30BrN. 531.1562.
According to the same method for synthesizing Intermediate 2-b, Intermediate 66-c was synthesized using Intermediate 66-b instead of Intermediate 2-a (yield: 67%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 66-c.
ESI-LCMS: [M]+: C40H33BrClN. 641.1485.
According to the same method for synthesizing Intermediate 2-c, Intermediate 66-d was synthesized using Intermediate 66-c instead of Intermediate 2-b (yield: 75%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 66-d.
ESI-LCMS: [M]+: C62H55ClN2. 862.4054.
According to the same method for synthesizing Intermediate 2-d, Intermediate 66-e was synthesized using Intermediate 66-d instead of Intermediate 2-c (yield: 63%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 66-e.
ESI-LCMS: [M]+: C68H59ClN2. 938.4367.
According to the same method for synthesizing Intermediate 2-e, Intermediate 66-f was synthesized using Intermediate 66-e instead of Intermediate 2-d (yellow solid, 30%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 66-f.
ESI-LCMS: [M]+: C68H56BClN2. 946.4225.
According to the same method for synthesizing Intermediate 2-f, Intermediate 66-g was synthesized using Intermediate 66-f instead of Intermediate 2-e (yield: 52%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 66-g.
ESI-LCMS: [M]+: C68H55BBrClN2. 1024.3330.
According to the same method for synthesizing Intermediate 2-g, Intermediate 66-h was synthesized using Intermediate 66-g instead of Intermediate 2-f (yield: 66%). Through ESJ-LCMS, the solid thus obtained was identified as Intermediate 66-h.
ESJ-LCMS: [M]+: C92H74BClN2Si. 1280.5403.
According to the same method for synthesizing Compound 2, Compound 66 was synthesized using Intermediate 66-h instead of Intermediate 2-g (yellow solid, yield: 70%). Through 1H-NMR and ESI-LCMS, the yellow solid thus obtained was identified as Compound 66.
1H-NMR (400 MHz, CDCl3): d=9.10 (d, 1H), 9.02 (s, 1H), 7.87-7.83 (m, 4H), 7.77-7.71 (m, 8H), 7.68-7.62 (m, 5H), 7.48-7.38 (m, 15H), 7.24-7.15 (m, 12H), 7.11-7.01 (m, 8H), 6.30-6.27 (s, 2H), 1.40-1.38 (s, 18H).
ESI-LCMS: [M]+: C104H74D8BN3Si. 1419.6874.
Compound 78 according to an embodiment may be synthesized, for example, by the reaction below.
According to the same method for synthesizing Intermediate 66-a, Intermediate 78-a was synthesized using (3,5-di-tert-butylphenyl)boronic acid instead of phenylboronic acid (yield: 62%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 78-a.
ESI-LCMS: [M]+: C20H24Br2. 424.2200.
According to the same method for synthesizing Intermediate 2-a, Intermediate 78-b was synthesized using Intermediate 78-a instead of 1,3-dibromo-5-(tert-butyl)benzene (yield: 70%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 78-b.
ESI-LCMS: [M]+: C42H46BrN. 643.2813.
According to the same method for synthesizing Intermediate 2-b, Intermediate 78-c was synthesized using Intermediate 78-b instead of Intermediate 2-a (yield: 65%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 78-c.
ESI-LCMS: [M]+: C48H49BrClN. 754.2737.
According to the same method for synthesizing Intermediate 2-c, Intermediate 78-d was synthesized using Intermediate 78-c instead of Intermediate 2-b (yield: 75%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 78-d.
ESI-LCMS: [M]+: C70H71ClN2. 974.5306.
According to the same method for synthesizing Intermediate 2-d, Intermediate 78-e was synthesized using Intermediate 78-d instead of Intermediate 2-c (yield: 69%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 78-e.
ESI-LCMS: [M]+: C76H75ClN2. 1050.5619.
According to the same method for synthesizing Intermediate 2-e, Intermediate 78-f was synthesized using Intermediate 78-e instead of Intermediate 2-d (yield: 34%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 78-f.
ESI-LCMS: [M]+: C76H72BClN2. 1058.5477.
According to the same method for synthesizing Intermediate 2-f, Intermediate 78-g was synthesized using Intermediate 78-f instead of Intermediate 2-e (yield: 52%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 78-g.
ESI-LCMS: [M]+: C76H71BBrClN2. 1136.4582.
According to the same method for synthesizing Intermediate 2-g, Intermediate 78-h was synthesized using Intermediate 78-g instead of Intermediate 2-f (yield: 69%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 78-h.
ESI-LCMS: [M]+: C92H74BClN2Si. 1280.5403.
According to the same method for synthesizing Compound 2, Compound 78 was synthesized using Intermediate 78-h instead of Intermediate 2-g and using 3,6-bis(methyl-d3)-9H-carbazole instead of 9H-carbazole-1,2,3,4,5,6,7,8-d8 (yield: 72%). Through 1H-NMR and ESI-LCMS, the yellow solid thus obtained was identified as Compound 78.
1H-NMR (400 MHz, CDCl3): d=9.05 (d, 1H), 9.03 (s, 1H), 8.53-8.32 (m, 6H), 7.76-7.70 (m, 4H), 7.65-7.59 (m, 8H), 7.57-7.53 (m, 5H), 7.50-7.40 (m, 15H), 7.23-7.16 (m, 10H), 7.12-7.05 (m, 8H), 6.45-6.43 (s, 2H), 1.50-1.47 (S, 18H), 1.40-1.38 (s, 18H).
ESI-LCMS: [M]+: C114H96D6BN3Si. 1557.8313.
Compound 83 according to an embodiment may be synthesized, for example, by the reaction below.
According to the same method for synthesizing Intermediate 2-d, Intermediate 83-a was synthesized using Intermediate 3-a instead of Intermediate 2-c (yield: 68%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 83-a.
ESI-LCMS: [M]+: C40H34BrN2. 607.1875.
According to the same method for synthesizing Intermediate 2-c, Intermediate 83-b was synthesized using Intermediate 83-a instead of Intermediate 2-b and using 5′-phenyl-[1,1′:3′,1″-terphenyl]-2′-amine instead of 5′-(tert-butyl)-[1,1′:3′,1″-terphenyl]-2′-amine (yield: 75%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 83-b.
ESI-LCMS: [M]+: C64H52N2. 848.4130.
According to the same method for synthesizing Intermediate 2-d, Intermediate 83-c was synthesized using Intermediate 83-b instead of Intermediate 2-c (yield: 65%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 83-c.
ESI-LCMS: [M]+: C76H60N2. 1000.4756.
According to the same method for synthesizing Intermediate 2-e, Intermediate 83-d was synthesized using Intermediate 83-c instead of Intermediate 2-d (yellow solid, 31%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 83-d.
ESI-LCMS: [M]+: C76H57BN2. 1008.4615.
According to the same method for synthesizing Intermediate 2-f, Intermediate 83-e was synthesized using Intermediate 83-d instead of Intermediate 2-e (yield: 51%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 83-e.
ESI-LCMS: [M]+: C76H56BBrN2. 1086.3720.
According to the same method for synthesizing Intermediate 2-g, Compound 83 was synthesized using Intermediate 83-e instead of Intermediate 2-f (yield: 65%). Through 1H-NMR and ESI-LCMS, the yellow solid thus obtained was identified as Compound 83.
1H-NMR (400 MHz, CDCl3): δ=9.16 (d, 1H), 9.14 (s, 1H), 7.88-7.84 (m, 4H), 7.80-7.75 (m, 6H), 7.60-7.57 (s, 4H), 7.50-7.40 (m, 17H), 7.27-7.15 (m, 12H), 7.13-7.04 (m, 8H), 7.03-6.89 (m, 11H), 6.50-6.48 (s, 2H), 1.35-1.32 (s, 9H).
ESI-LCMS: [M]+: C100H75BN2Si. 1342.5793.
Compound 101 according to an embodiment may be synthesized, for example, by the reaction below.
According to the same method for synthesizing Intermediate 2-d, Intermediate 101-a was synthesized using 1-bromo-3-iodobenzene instead of iodobenzene (yield: 63%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 101-a.
ESI-LCMS: [M]+: C66H66BrClN2. 996.3785.
According to the same method for synthesizing Intermediate 2-c, Intermediate 101-b was synthesized using Intermediate 101-a instead of Intermediate 2-d (yellow solid, 25%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 101-b.
ESI-LCMS: [M]+: C66H59BBrClN2. 1004.3643.
According to the same method for synthesizing Intermediate 2-g, Intermediate 101-c was synthesized using Intermediate 101-b instead of Intermediate 2-f (yield: 68%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 101-c.
ESI-LCMS: [M]+: C90H78BClN2Si. 1260.5716.
According to the same method for synthesizing Compound 2, Compound 101 was synthesized using Intermediate 101-c instead of Intermediate 2-g (yellow solid, yield: 70%). Through 1H-NMR and ESI-LCMS, the yellow solid thus obtained was identified as Compound 101.
1H-NMR (400 MHz, CDCl3): d=9.18 (d, 1H), 9.10 (d, 1H), 7.90-7.86 (m, 4H), 7.78-7.72 (m, 4H), 7.58-7.51 (s, 4H), 7.40-7.28 (m, 15H), 7.21-7.10 (m, 12H), 7.08-6.98 (m, 8H), 6.53-6.50 (s, 2H), 1.41-1.39 (s, 18H), 1.35-1.32 (s, 9H).
ESI-LCMS: [M]+: C102H78D8BN3Si. 1399.7186.
Compound 107 according to an embodiment may be synthesized, for example, by the reaction below.
According to the same method for synthesizing Intermediate 2-g, Intermediate 107-a was synthesized using (3-(triphenylsilyl)phenyl)boronic acid instead of (4-(triphenylsilyl)phenyl)boronic acid (yield: 70%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 107-a.
ESI-LCMS: [M]+: C90H78BClN2Si. 1260.5716.
According to the same method for synthesizing Compound 2, Compound 107 was synthesized using Intermediate 107-a instead of Intermediate 2-g (yellow solid, yield: 68%). Through 1H-NMR and ESI-LCMS, the yellow solid thus obtained was identified as Compound 107.
1H-NMR (400 MHz, CDCl3): δ=9.15 (d, 1H), 9.12 (s, 1H), 7.89-7.80 (m, 4H), 7.75-7.65 (m, 4H), 7.43-7.40 (s, 4H), 7.38-7.28 (m, 15H), 7.20-7.12 (m, 12H), 7.08-6.99 (m, 8H), 6.20-6.18 (s, 2H), 1.41-1.39 (s, 18H), 1.35-1.32 (s, 9H).
ESI-LCMS: [M]+: C102H78D8BN3Si. 1399.7186.
Compound 113 according to an embodiment may be synthesized, for example, by the reaction below.
According to the same method for synthesizing Intermediate 2-a, Intermediate 113-a was synthesized using 5-(tert-butyl)-[1,1′-biphenyl]-2-amine instead of 5′-(tert-butyl)-[1,1′:3′,1″-terphenyl]-2′-amine (yield: 54%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 113-a.
ESI-LCMS: [M]+: C36H30BrN. 435.1562.
According to the same method for synthesizing Intermediate 2-b, Intermediate 113-b was synthesized using Intermediate 113-a instead of Intermediate 2-a (yield: 85%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 113-b.
ESI-LCMS: [M]+: C32H33BrClN. 545.1485.
According to the same method for synthesizing Intermediate 2-c, Intermediate 113-c was synthesized using Intermediate 113-b instead of Intermediate 2-b (yield: 71%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 113-c.
ESI-LCMS: [M]+: C54H55ClN2. 766.4054.
According to the same method for synthesizing Intermediate 2-d, Intermediate 113-d was synthesized using Intermediate 113-c instead of Intermediate 2-c (yield: 62%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 113-d.
ESI-LCMS: [M]+: C60H59ClN2. 842.4367.
According to the same method for synthesizing Intermediate 2-e, Intermediate 113-e was synthesized using Intermediate 113-d instead of Intermediate 2-d (yellow solid, 26%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 113-e.
ESI-LCMS: [M]+: C60H56BClN2. 850.4225.
According to the same method for synthesizing Intermediate 2-f, Intermediate 113-f was synthesized using Intermediate 113-e instead of Intermediate 2-e (yield: 53%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 113-f.
ESI-LCMS: [M]+: C60H55BBrN2. 928.3330.
According to the same method for synthesizing Intermediate 2-g, Intermediate 113-g was synthesized using Intermediate 113-f instead of Intermediate 2-f (yield: 64%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 113-g.
ESI-LCMS: [M]+: C84H74BClN2Si. 1184.5403.
According to the same method for synthesizing Compound 2, Compound 113 was synthesized using Intermediate 113-g instead of Intermediate 2-g (yellow solid, yield: 70%). Through 1H-NMR and ESI-LCMS, the yellow solid thus obtained was identified as Compound 113.
1H-NMR (400 MHz, CDCl3): δ=9.15 (d, 1H), 9.12 (s, 1H), 7.89-7.80 (m, 4H), 7.75-7.65 (m, 4H), 7.43-7.40 (s, 4H), 7.38-7.28 (m, 15H), 7.20-7.12 (m, 12H), 7.08-6.99 (m, 8H), 6.20-6.18 (s, 2H), 1.41-1.39 (s, 18H), 1.35-1.32 (s, 9H).
ESI-LCMS: [M]+: C102H78D8BN3Si. 1399.7186.
Compound 117 according to an embodiment may be synthesized, for example, by the reaction below.
Under an argon atmosphere, to a 1 L flask, the compound of 2-bromodibenzo[b,d]furan (1 eq) was dissolved in THF (excess), the temperature was reduced to about −78 degrees, and 2.5 M n-BuLi (0.95 eq) was added thereto dropwise to produce Intermediate 1. In another flask, 1,4-dibromobenzene (1 eq) was dissolved in THF (excess), the temperature was reduced to about −78 degrees, 2.5 M n-BuLi (1 eq) was added thereto dropwise, followed by stirring for about 3 hours, and dichlorodiphenylsilane (1 eq) was added thereto. Intermediate 1 synthesized above was added thereto, the temperature was slowly elevated to room temperature, and the mixture was stirred for about 10 hours. After finishing the reaction, water and ethyl acetate were added, extraction was performed, and organic layers were collected, dried over MgSO4, and filtered. The solvent of the filtrate solution was removed under a reduced pressure, and the solid thus obtained was purified and separated by column chromatography using CH2Cl2 and hexane as developing solvents to obtain Intermediate 117-a (yield: 38%). Through ESI-LCMS, the compound thus obtained was identified as Intermediate 117-a.
ESI-LCMS: [M]+: C30H21BrOSi. 504.0545.
Under an argon atmosphere, to a 2 L flask, Intermediate 117-a (1 eq), bis(pinacolato)diboron (1.2 eq), bis(triphenylphosphine)palladium(II) dichloride (0.03 g) and potassium carbonate (2 eq) were added and dissolved in 1,4-dioxane, and the reaction solution was stirred at about 120 degrees for about 12 hours. After cooling, water (1 L) and ethyl acetate (300 mL) were added, extraction was performed, and organic layers were collected, dried over MgSO4, and filtered. The solvent of the filtrate solution was removed under a reduced pressure, and the solid thus obtained was purified and separated by column chromatography using CH2Cl2 and hexane as developing solvents to obtain Intermediate 117-b (yield: 70%). Through ESI-LCMS, the compound thus obtained was identified as Intermediate 117-b.
ESI-LCMS: [M]+: C36H33BO3Si. 552.2292.
According to the same method for synthesizing Intermediate 2-g, Intermediate 117-c was synthesized using Intermediate 117-b instead of (4-(triphenylsilyl)phenyl)boronic acid (yield: 68%). Through ESI-LCMS, the solid thus obtained was identified as Intermediate 117-c.
ESI-LCMS: [M]+: C96H80BClN2OSi. 1350.5821.
According to the same method for synthesizing Compound 2, Compound 117 was synthesized using Intermediate 117-c instead of Intermediate 2-g (yellow solid, yield: 71%). Through 1H-NMR and ESI-LCMS, the yellow solid thus obtained was identified as Compound 117.
1H-NMR (400 MHz, CDCl3): d=9.11 (d, 1H), 9.09 (s, 1H), 7.90-7.80 (m, 8H), 7.75-7.64 (m, 4H), 7.55-7.52 (s, 4H), 7.42-7.25 (m, 15H), 7.20-7.12 (m, 10H), 7.08-6.99 (m, 8H), 6.60-6.57 (s, 2H), 1.41-1.39 (s, 18H), 1.35-1.32 (s, 9H).
ESI-LCMS: [M]+: C108H80D8BN3OSi. 1489.7292.
The light emitting element according to an embodiment, including the fused polycyclic compound according to an embodiment in an emission layer, was manufactured by a method below. Light emitting elements of Example 1 to Example 10 were manufactured using Compounds 2, 3, 34, 66, 78, 83, 101, 107, 113, and 117, respectively, as the dopant materials of an emission layer. Comparative Examples 1 to 5 correspond to light emitting elements manufactured using Comparative Compounds C1 to C5 as the dopant materials of an emission layer.
For the manufacture of the light emitting elements of the Examples and Comparative Examples, a glass substrate on which an ITO electrode of about 15 Ω/cm2 (1200 Å) was formed (a product of Corning Co.) was cut to a size of about 50 mm×50 mm×0.7 mm, cleansed with ultrasonic waves using isopropyl alcohol and pure water for about 5 minutes each, exposed to ultraviolet for about 30 minutes, cleansed by exposing to ozone to form an anode, and the anode was installed in a vacuum evaporation apparatus.
On the anode, NPD was deposited to form a hole injection layer with a thickness of about 300 Å. On the hole injection layer, Compound H-1-1 was deposited to form a hole transport layer with a thickness of about 200 Å. On the hole transport layer, CzSi was deposited to form an electron blocking layer with a thickness of about 100 Å.
A mixed host obtained by mixing a second compound and a third compound according to an embodiment at a ratio of about 1:1, the fourth compound, and the Example Compound or the Comparative Compound were co-deposited at a weight ratio of about 85:14:1 to form an emission layer with a thickness of about 350 Å. On the emission layer, Compound ETH2 from Compound Group 3 was deposited to form a hole blocking layer with a thickness of about 50 Å. On the hole blocking layer, CNNPTRZ:Liq were co-deposited at a weight ratio of about 4.0:6.0 to form an electron transport layer with a thickness of about 310 Å. On the electron transport layer, Yb was deposited to form an electron injection layer with a thickness of about 15 Å. On the electron injection layer, Mg was deposited to form a cathode with a thickness of about 800 Å to manufacture a light emitting element.
All layers were formed by a vacuum deposition method. Compound HT35 from Compound Group 2 was used as the second compound, Compound ETH66 from Compound Group 3 was used as the third compound, and Compound AD-38 from Compound Group 4 was used as the fourth compound.
The compounds used for the manufacture of the light emitting elements of the Examples and Comparative Examples are shown below. The materials below were used after purchasing commercial products and performing sublimation purification.
The element efficiency and element lifetime of the light emitting elements manufactured by using Compounds 2, 3, 34, 66, 78, 83, 101, 107, 113 and 117 and Comparative Compounds C1 to C5 were evaluated. In Table 1, the evaluation results on the light emitting elements of Examples 1 to 10, and Comparative Examples 1 to 5 are shown. In the evaluation results of the properties on the Examples and Comparative Examples, shown in Table 1, the driving voltage and the current density were measured using V7000 OLED IVL Test System (Polaronix). For the evaluation of the properties of the light emitting elements manufactured in Examples 1 to 10 and Comparative Examples 1 to 5, driving voltages (V) at a current density of about 1000 cd/m2, emission efficiency (Cd/A), and emission wavelengths were measured using Keithley MU 236 and a luminance meter PR650. The time consumed to reach about 95% luminance in contrast to an initial luminance was measured as the lifetime (T95), relative lifetime was calculated on the basis of the light emitting element of Comparative Example 1, and the results are shown in Table 1.
Referring to Table 1, it could be confirmed that the light emitting elements of the Examples, using the fused polycyclic compounds according to embodiments as light emitting materials, showed improved emission efficiency and lifetime characteristics when compared to the Comparative Examples.
The fused polycyclic compounds of the Examples each includes a structure in which a phenyl group is connected to a fused ring core and may show improved thermally activated delayed fluorescence properties. In the fused polycyclic compound, a local excited triplet energy level (3LE) localized in the “diaryl part”, corresponding to the first benzene ring of the fused ring core and a phenyl group connected therewith, may serve as a medium that increases a reverse inter system crossing rate between the excited triplet energy level and the singlet excited energy level. Reverse inter system crossing (RISC) is mediated through the local excited triplet energy level (3LE) having relatively large spin-orbit interaction, exciton energy may move fast through a pass of T1→3LE→Si, and accordingly, the reverse inter system crossing (RISC) rate may increase to improve emission efficiency. The fused polycyclic compound according to an embodiment includes a silyl group having large bulkiness as a substituent, thereby increasing intermolecular distance, so that Dexter energy transfer may be prevented, and thus, element performance may be improved. Further, since the fused polycyclic compound according to an embodiment includes first and second substituents as described above, a boron atom may be effectively protected, intermolecular interaction may be suppressed, and the formation of excimers or exciplexes may be controlled, thereby improving emission efficiency. Since the light emitting element according to an embodiment includes the fused polycyclic compound according to an embodiment as a light emitting dopant of a thermally activated delayed fluorescence (TADF) light emitting element, high element efficiency and improved life-characteristics in a blue wavelength region may be achieved.
Comparative Example 1 showed degraded results of element lifetime and efficiency in contrast to the Examples. Comparative Compound C1, included in Comparative Example 1 includes a fused polycyclic heterocycle with one boron atom and two nitrogen atom in the center, but does not include an aryl group connected with the fused polycyclic heterocycle. Accordingly, the increasing effects of reverse inter system crossing rate through the local excited triplet energy level (3LE) is difficult to predict. Comparative Compound C1 does not include the silyl group and the first and second substituents as described above, and the protection effects of a boron atom may be degraded, and intermolecular interaction may not be sufficiently prevented, in contrast to the Example Compounds.
Comparative Example 2 and Comparative Example 5 each showed degraded results of element lifetime and efficiency in contrast to the Examples. Comparative Compound C2 and Comparative Compound C5, included in Comparative Example 2 and Comparative Example 5, each include a phenyl group connected with the fused polycyclic heterocycle but do not include a silyl group and a second substituent as described above. Accordingly, the boron atom may not be sufficiently protected, and Dexter energy transfer may not be sufficiently controlled in contrast to the Example Compounds.
Comparative Example 3 showed degraded results of element lifetime and efficiency in contrast to the Examples. Comparative Compound C3 included in Comparative Example 3 differs from the Example Compounds in that a carbazole group rather than a phenyl group is connected with a fused ring core in contrast to the Example Compounds. Accordingly, it is difficult to expect that Comparative Compound C3 shows increasing effects of the reverse inter system crossing rate in contrast to the Examples.
When comparing Comparative Example 4 to Example 1, it can be confirmed that Comparative Example 4 showed degraded element lifetime and efficiency in contrast to Example 1. Comparative Compound C4 included in Comparative Example 4 differs from Compound 2 included in Example 1 in having a structure in which a methyl group rather than a phenyl group is substituted at an ortho position of the phenyl group with respect to a nitrogen atom of the fused ring core. A methyl group is a very weak substituent in view of thermal stability, and if a methyl group is introduced instead of a phenyl group as a substituent, it is very inferior in view of the stability of a material, steric hindrance effects may be insufficient in contrast to the phenyl group, and it can be weak in view of the protection of a boron atom and the control of Dexter energy transfer.
The fused polycyclic compound according to an embodiment may be used in an emission layer and may contribute to the increase of efficiency and lifetime. The fused polycyclic compound according to an embodiment includes a fused ring core with a boron atom and first and second nitrogen atoms, and includes an aryl group connected at a specific position of the fused ring core, and thus, may show improved thermally activated delayed fluorescence properties. The fused polycyclic compound according to an embodiment includes a silyl group connected with the aryl group, and first and second substituents connected with the first and second nitrogen atoms, respectively, and may have excellent optical properties and high material stability. Accordingly, if the fused polycyclic compound according to an embodiment is introduced in the emission layer of a light emitting element, high emission efficiency and long lifetime can be achieved.
The light emitting element according to an embodiment may show improved element properties of high efficiency and long lifetime.
The fused polycyclic compound according to an embodiment may be included in the emission layer of a light emitting element and may contribute to the increase of the efficiency and lifetime of the light emitting element.
The display device according to an embodiment may show 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 |
|---|---|---|---|
| 10-2023-0129446 | Sep 2023 | KR | national |
