Patent Application
20240074310
This application claims priority to and benefits of Korean Patent Application No. 10-2022-0099992 under 35 U.S.C. § 119, filed on Aug. 10, 2022, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.
Embodiments relate to a light-emitting device, and a display apparatus and an electronic apparatus each including the light-emitting device.
Light-emitting devices are devices that convert electrical energy into light energy. Examples of such light-emitting devices include organic light-emitting devices using organic materials for an emission layer, quantum dot light-emitting devices using quantum dots for an emission layer, and the like.
The light-emitting device may have a structure in which a first electrode is arranged on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode are sequentially stacked on the first electrode.
Holes provided from the first electrode move toward the emission layer through the hole transport region, and electrons provided from the second electrode move toward the emission layer through the electron transport region. Carriers, such as holes and electrons, recombine in the emission layer to produce excitons. These excitons transition from an excited state to a ground state, thereby generating light.
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.
Embodiments include a light-emitting device having excellent color reproducibility, and a display apparatus and an electronic apparatus each including the light-emitting device.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the embodiments of the disclosure.
According to embodiments, a light-emitting device may include a first electrode, a second electrode facing the first electrode, and light-emitting units between the first electrode and the second electrode, wherein the light-emitting units may include at least one first light-emitting unit and at least one second light-emitting unit, the first light-emitting unit may include a first emission layer including a first host and a first dopant, the second light-emitting unit may include a second emission layer including a second host, a third host, and a second dopant, the first host may include a first compound represented by Formula 1, the second host may include at least one second compound each independently represented by one of Formulae 2a to 2c, the third host may include a third compound represented by Formula 3, the first compound and the second compound may each independently have a deuterium substitution ratio greater than or equal to 20%, and the deuterium substitution ratio may be a ratio of hydrogen substituted with deuterium:
In Formulae 1, 2a to 2c, and 3,
In an embodiment, L1 to L15 may each independently be a single bond, a C1-C20 alkylene group unsubstituted or substituted with at least one R10a, a C2-C20 alkenylene group unsubstituted or substituted with at least one R10a, a C2-C20 alkynylene group unsubstituted or substituted with at least one R10a, a C3-C1 cycloalkylene group unsubstituted or substituted with at least one R10a, a C1-C1 heterocycloalkylene group unsubstituted or substituted with at least one R10a, a C3-C1 cycloalkenylene group unsubstituted or substituted with at least one R10a, a C1-C1 heterocycloalkenylene group unsubstituted or substituted with at least one R10a, a C6-C60 arylene group unsubstituted or substituted with at least one R10a, a C1-C60 heteroarylene group unsubstituted or substituted with at least one R10a, a divalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R10a, or a divalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R10a.
In an embodiment, L1 to L15 may each independently be: a single bond; or a benzene group, a naphthalene group, a phenanthrene group, a pyrene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinazoline group, a quinoxaline group, a naphthyridine group, a benzoquinoline group, a benzoisoquinoline group, a benzoquinazoline group, a benzoquinoxaline group, a benzonaphthyridine group, a pyridoquinoline group, a pyridoisoquinoline group, a pyridoquinazoline group, a pyridoquinoxaline group, a pyridonaphthyridine group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a pyridopyrazole group, a pyridoimidazole group, a pyridoxazole group, a pyridothiazole group, a pyridopyrrole group, a pyridofuran group, or a pyridothiophene group, each unsubstituted or substituted with deuterium, a C1-C20 alkyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a phenanthrenyl group, a pyrenyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinazolinyl group, a quinoxalinyl group, a naphthyridinyl group, a benzoquinolinyl group, a benzoisoquinolinyl group, a benzoquinazolinyl group, a benzoquinoxalinyl group, a benzonaphthyridinyl group, a pyridoquinolinyl group, a pyridoisoquinolinyl group, a pyridoquinazolinyl group, a pyridoquinoxalinyl group, a pyridonaphthyridinyl group, a benzopyrazolyl group, a benzoimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, a pyridopyrazolyl group, a pyridoimidazolyl group, a pyridoxazolyl group, a pyridothiazolyl group, a pyridopyrrolyl group, a pyridofuranyl group, a pyridothiophenyl group, or any combination thereof.
In an embodiment, Ar1 to Ar13 may each independently be a C6-C60 aryl group or a C1-C60 heteroaryl group, each unsubstituted or substituted with a deuterium group.
In an embodiment, Ar1 to Ar13 may each independently be a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group, a spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, an indolyl group, an isoindolyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, a dibenzothiophenyla fluorenyl group, an azacarbazolyl group, a diazacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, an imidazopyridinyl group, or an imidazopyrimidinyl group, each unsubstituted or substituted with a deuterium group.
In an embodiment, R1 to R6 may each independently be:
In an embodiment, the first compound or the second compound may each independently have a deuterium substitution ratio greater than or equal to 30%.
In an embodiment, the first compound or the second compound may each independently have a deuterium substitution ratio less than or equal to 50%.
In an embodiment, the third compound may not include deuterium.
In an embodiment, the first compound may include one of Formulae 1-1 to 1-13, which are explained below.
In an embodiment, the second compound may include one of Formulae 2-1 to 2-14, which are explained below.
In an embodiment, the third compound may include one of Formulae 3-1 to 3-9, which are explained below.
In an embodiment, the first light-emitting unit may be a blue light-emitting unit emitting blue light, and the second light-emitting unit may be a green light-emitting unit emitting green light.
In an embodiment, the first dopant and the second dopant may each independently be a fluorescent dopant, a delayed fluorescence dopant, a phosphorescent dopant, or any combination thereof.
In an embodiment, the light-emitting units may be stacked, and the light-emitting device may further include a charge generation layer between adjacent light-emitting units.
In an embodiment, the light-emitting device may include three blue light-emitting units and one green light-emitting unit.
According to embodiments, a display apparatus may include the light-emitting device, which is arranged on a substrate, and a light controller corresponding to the light-emitting device, wherein the light controller may include a capping layer, a color conversion layer, and a color filter layer.
In an embodiment, the color conversion layer may include a quantum dot layer.
According to embodiments, an electronic apparatus may include the light-emitting device.
In an embodiment, the electronic apparatus may further include a thin-film transistor, wherein the thin-film transistor may include a source electrode and a drain electrode, and the first electrode of the light-emitting device may be electrically connected to at least one of the source electrode and the drain electrode.
It is to be understood that the embodiments above are described in a generic and explanatory sense only and not for the purpose of limitation, and the disclosure is not limited to the embodiments described above.
The above and other aspects and features of the disclosure will be 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 numbers and characters refer to like elements throughout.
In the description, 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 description, 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.
When an embodiment is implemented in a different manner, a process order may be performed differently than what is described herein. For example, two processes described in succession may be performed substantially simultaneously, or they may be performed in an order opposite to the described order.
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.
[Description of
The interlayer 130 may include multiple light-emitting units (not shown) and one or more charge generation layers (not shown) arranged between adjacent light-emitting units. Each of the light-emitting units may include an emission layer (not shown), and may further include a hole transport region and an electron transport region. At least one of the one or more charge generation layers may include an n-type charge generation layer and a p-type charge generation layer.
Hereinafter, a structure of the light-emitting device 10 according to an embodiment will be described in detail with reference to
[First Electrode]
In
The first electrode 110 may be formed by, for example, depositing or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, a material for forming the first electrode 110 may be a high-work function material that facilitates the injection of holes.
The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, a material for forming the first electrode 110 may include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), zinc oxide (ZnO), or any combination thereof. In embodiments, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, a material for forming the first electrode 110 may include magnesium (Mg), silver (Ag), aluminum (AI), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or any combination thereof.
The first electrode 110 may have a structure consisting of a single layer or a structure including multiple layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO.
[Light-Emitting Unit of Interlayer 130]
The interlayer 130 may include multiple light-emitting units. The light-emitting units may be stacked. For example, the light-emitting units may be stacked in a thickness direction between the first electrode and the second electrode. Although it is not shown in the drawings, each of the light-emitting units may include an emission layer, and may further include an electron transport region and/or a hole transport region. A charge generation layer may be arranged between adjacent light-emitting units.
The hole transport regions may each independently include a hole injection layer, a hole transport layer, an electron blocking layer, or any combination thereof. The electron transport regions may each independently include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.
The interlayer 130 may include, for example, two, three, four, five, or six light-emitting units. However, embodiments are not limited thereto.
In an embodiment, the light-emitting units may include at least one blue light-emitting unit and at least one green light-emitting unit, so that the light-emitting device 10 may emit white light. In an embodiment, the interlayer may include three or four light-emitting units. A portion of the light-emitting units may emit blue light and the remainder of the light-emitting units may emit green light, such that the light-emitting device 10 may emit white light. In an embodiment, the interlayer may include three blue light-emitting unit and one green light-emitting unit, such that the light-emitting device 10 may emit white light.
In an embodiment, a host of a blue light-emitting unit may be different from a host of a green light-emitting unit. In an embodiment, the emission layer of the blue light-emitting unit may use a single host, and the emission layer of the green light-emitting unit may use a mixed host of a hole transport host and an electron transport host. In an embodiment, the host of the emission layer of the blue light-emitting unit and the hole transport host of the green light-emitting unit may each independently have a deuterium substitution ratio greater than or equal to 20%.
Hereinafter, the hole transport region, the emission layer, and the electron transport region in each light-emitting unit are described in detail.
[Hole Transport Region in Light-Emitting Unit]
A hole transport region may have a structure consisting of a layer consisting of a single material, a structure consisting of a layer including different materials, or a structure including multiple layers including different materials.
A hole transport region may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof.
In embodiments, a hole transport region may have a multi-layered structure including a hole injection layer/hole transport layer structure, a hole injection layer/hole transport layer/emission auxiliary layer structure, a hole injection layer/emission auxiliary layer structure, a hole transport layer/emission auxiliary layer structure, or a hole injection layer/hole transport layer/electron-blocking layer structure, wherein the layers of each structure may be stacked from the first electrode 110 in its respective stated order, but the structure of a hole transport region is not limited thereto.
A hole transport region may include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof:
In Formulae 201 and 202,
xa1 to xa4 may each independently be an integer from 0 to 5,
xa5 may be an integer from 1 to 10,
na1 may be an integer from 1 to 4.
In embodiments, the compound represented by Formula 201 and the compound represented by Formula 202 may each independently include at least one of groups represented by Formulae CY201 to CY217:
In Formulae CY201 to CY217, R10b and R10c may each independently be the same as described with respect to R10a, ring CY201 to ring CY204 may each independently be a C3-C20 carbocyclic group or a C1-C20 heterocyclic group, and at least one hydrogen in Formulae CY201 to CY217 may be unsubstituted or substituted with R10a as described above.
In an embodiment, in Formulae CY201 to CY217, ring CY201 to ring CY204 may each independently be a benzene group, a naphthalene group, a phenanthrene group, or an anthracene group.
In embodiments, the compound represented by Formula 201 and the compound represented by Formula 202 may each independently include at least one of groups represented by Formulae CY201 to CY203.
In embodiments, the compound represented by Formula 201 may include at least one of groups represented by Formulae CY201 to CY203 and at least one of groups represented by Formulae CY204 to CY217.
In embodiments, in Formula 201, xa1 may be 1, R201 may be a group represented by one of Formulae CY201 to CY203, xa2 may be 0, and R202 may be a group represented by one of Formulae CY204 to CY207.
In embodiments, the compound represented by Formula 201 and the compound represented by Formula 202 may each not include a group represented by one of Formulae CY201 to CY203.
In embodiments, the compound represented by Formula 201 and the compound represented by Formula 202 may each not include a group represented by one of Formulae CY201 to CY203, and may each independently include at least one of groups represented by Formulae CY204 to CY217.
In embodiments, the compound represented by Formula 201 and the compound represented by Formula 202 may each not include a group represented by one of Formulae CY201 to CY217.
In an embodiment, a hole transport region may include one of Compounds HT1 to HT46, m-MTDATA, TDATA, 2-TNATA, NPB (NPD), p-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), or any combination thereof:
A thickness of a hole transport region may be in a range of about 50 Å to about 10,000 Å. For example, a thickness of a hole transport region may be in a range of about 100 Å to about 4,000 Å. When a hole transport region includes a hole injection layer, a hole transport layer, or any combination thereof, a thickness of a hole injection layer may be in a range of about 100 Å to about 9,000 Å, and a thickness of a hole transport layer may be in a range of about 50 Å to about 2,000 Å. For example, a thickness of a hole injection layer may be in a range of about 100 Å to about 1,000 Å. For example, a thickness of a hole transport layer may be in a range of about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.
The emission auxiliary layer may increase light-emission efficiency by compensating for an optical resonance distance according to a wavelength of light emitted by an emission layer, and the electron-blocking layer may block the leakage of electrons from an emission layer to a hole transport region. Materials that may be included in the hole transport region may be included in the emission auxiliary layer and the electron-blocking layer.
[p-Dopant]
A hole transport region may further include, in addition to these materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be uniformly or non-uniformly dispersed in the hole transport region (for example, in the form of a single layer consisting of a charge-generation material).
The charge-generation material may be, for example, a p-dopant.
In an embodiment, a lowest unoccupied molecular orbital (LUMO) energy level of the p-dopant may be less than or equal to about −3.5 eV.
In embodiments, the p-dopant may include a quinone derivative, a cyano group-containing compound, a compound including element EL1 and element EL2, or any combination thereof.
Examples of a quinone derivative may include TCNQ, F4-TCNQ, etc.
Examples of a cyano group-containing compound may include HAT-CN, and a compound represented by Formula 221:
In Formula 221,
at least one of R221 to R223 may each independently be a C3-C60 carbocyclic group or a C1-C60 heterocyclic group, each substituted with a cyano group; —F; —Cl ; —Br; —I; a C1-C20 alkyl group substituted with a cyano group, —F, —Cl, —Br, —I, or any combination thereof; or any combination thereof.
In the compound including element EL1 and element EL2, element EL1 may be a metal, a metalloid, or any combination thereof, and element EL2 may be a non-metal, a metalloid, or any combination thereof.
Examples of a metal may include: an alkali metal (for example, lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), etc.); an alkaline earth metal (for example, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), etc.); a transition metal (for example, titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), etc.); a post-transition metal (for example, zinc (Zn), indium (In), tin (Sn), etc.); and a lanthanide metal (for example, lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), etc.).
Examples of a metalloid may include silicon (Si), antimony (Sb), and tellurium (Te).
Examples of a non-metal may oxygen (O) and a halogen (for example, F, Cl, Br, I, etc.).
Examples of a compound including element EL1 and element EL2 may include metal oxide, a metal halide (for example, a metal fluoride, a metal chloride, a metal bromide, or a metal iodide), a metalloid halide (for example, a metalloid fluoride, a metalloid chloride, a metalloid bromide, or a metalloid iodide), a metal telluride, or any combination thereof.
Examples of a metal oxide may include tungsten oxide (for example, WO, W2O3, WO2, WO3, W2O5, etc.), vanadium oxide (for example, VO, V2O3, VO2, V2O5, etc.), molybdenum oxide (MoO, MO2O3, MoO2, MoO3, MO2O5, etc.), and rhenium oxide (for example, ReO3, etc.).
Examples of a metal halide may include an alkali metal halide, an alkaline earth metal halide, a transition metal halide, a post-transition metal halide, and a lanthanide metal halide.
Examples of an alkali metal halide may include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, etc.
Examples of an alkaline earth metal halide may include BeF2, MgF2, CaF2, SrF2, BaF2, BeCl2, MgCl2, CaCl2), SrCl2, BaCl2, BeBr2, MgBr2, CaBr2, SrBr2, BaBr2, BeI2, Mg12, CaI2, Sr12, and Bal2.
Examples of a transition metal halide may include a titanium halide (for example, TiF4, TiCl4, TiBr4, Til4, etc.), a zirconium halide (for example, ZrF4, ZrC14, ZrBr4, ZrI4, etc.), a hafnium halide (for example, HfF4, HfCl4, HfBr4, Hfl4, etc.), a vanadium halide (for example, VF3, VCl3, VBrs, V13, etc.), a niobium halide (for example, NbF3, NbCls, NbBrs, Nbl3, etc.), a tantalum halide (for example, TaF3, TaCl3, TaBrs, TaI3, etc.), a chromium halide (for example, CrF3, CrO3, CrBrs, Cr13, etc.), a molybdenum halide (for example, MoF3, MoCl3, MoBr3, Mol3, etc.), a tungsten halide (for example, WF3, WCl3, WBr3, WI3, etc.), a manganese halide (for example, MnF2, MnCl2, MnBr2, MnI2, etc.), a technetium halide (for example, TcF2, TcCl2, TcBr2, Tc12, etc.), a rhenium halide (for example, ReF2, ReCl2, ReBr2, ReI2, etc.), an iron halide (for example, FeF2, FeCl2, FeBr2, FeI2, etc.), a ruthenium halide (for example, RuF2, RuCl2, RuBr2, RuI2, etc.), an osmium halide (for example, OsF2, OsCl2, OsBr2, Os12, etc.), a cobalt halide (for example, CoF2, COCl2, CoBr2, CoI2, etc.), a rhodium halide (for example, RhF2, RhCl2, RhBr2, RhI2, etc.), an iridium halide (for example, IrF2, IrCl2, IrBr2, Ir12, etc.), a nickel halide (for example, NiF2, NiCl2, NiBr2, NiI2, etc.), a palladium halide (for example, PdF2, PdCl2, PdBr2, PdI2, etc.), a platinum halide (for example, PtF2, PtCl2, PtBr2, Pt12, etc.), a copper halide (for example, CuF, CuCl, CuBr, Cul, etc.), a silver halide (for example, AgF, AgCl, AgBr, Agl, etc.), and a gold halide (for example, AuF, AuCl, AuBr, Aul, etc.).
Examples of a post-transition metal halide may include a zinc halide (for example, ZnF2, ZnCl2, ZnBr2, Zn12, etc.), an indium halide (for example, Ink3, etc.), and a tin halide (for example, Sn12, etc.).
Examples of a lanthanide metal halide may include YbF, YbF2, YbF3, SmF3, YbCl, YbCl2, YbCls SmCl3, YbBr, YbBr2, YbBrs, SmBrs, YbI, YbI2, YbI3, Sm13, and the like.
An example of a metalloid halide may include an antimony halide (for example, SbCl5, etc.).
Examples of a metal telluride may include an alkali metal telluride (for example, Li2Te, Na2Te, K2Te, Rb2Te, Cs2Te, etc.), an alkaline earth metal telluride (for example, BeTe, MgTe, CaTe, SrTe, BaTe, etc.), a transition metal telluride (for example, TiTe2, ZrTe2, HfTe2, V2Te3, Nb2Te3, Ta2Te3, Cr2Te3, Mo2Te3, W2Te3, MnTe, TcTe, ReTe, FeTe, RuTe, OsTe, CoTe, RhTe, IrTe, NiTe, PdTe, PtTe, Cu2Te, CuTe, Ag2Te, AgTe, Au2Te, etc.), a post-transition metal telluride (for example, ZnTe, etc.), and a lanthanide metal telluride (for example, LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, etc.)
[Emission Layer in Light-Emitting Unit]
An emission layer may include a host and a dopant. The dopant may include a phosphorescent dopant, a fluorescent dopant, or any combination thereof. Optionally, an emission layer may include a delayed fluorescence material as the dopant.
An amount of the dopant in the emission layer may be in a range of about 0.01 parts by weight to about 15 parts by weight, based on 100 parts by weight of the host.
A thickness of an emission layer may be in a range of about 100 Å to about 1,000 Å. For example, a thickness of an emission layer may be in a range of about 200 Å to about 600 Å. When the thickness of an emission layer is within these ranges, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.
[Host]
The emission layer of the blue light-emitting unit may include first host including a first compound represented by Formula 1. The emission layer of the green light-emitting unit may include: a second host including at least one second compound each independently represented by one of Formulae 2a to 2c; and a third host including a third compound represented by Formula 3:
In Formulae 1, 2a to 2c, and 3,
The first compound represented by Formula 1 and the second compound represented by one of Formulae 2a to 2c may each independently have a deuterium substitution ratio greater than or equal to 20%. For example, a ratio, expressed as a percentage, of hydrogen in the first compound represented by Formula 1 that is substituted with deuterium 1 may be greater than or equal to 20%.
In an embodiment, L1 to L15 may each independently be a single bond, a C1-C20 alkylene group that is unsubstituted or substituted with at least one R10a, a C2-C20 alkenylene group that is unsubstituted or substituted with at least one R10a, a C2-C20 alkynylene group that is unsubstituted or substituted with at least one R10a, a C3-C1 cycloalkylene group that is unsubstituted or substituted with at least one R10a, a C1-C11 heterocycloalkylene group that is unsubstituted or substituted with at least one R10a, a C3-C10 cycloalkenylene group that is unsubstituted or substituted with at least one R10a, a C1-C10 heterocycloalkenylene group that is unsubstituted or substituted with at least one R10a, a C6-C60 arylene group that is unsubstituted or substituted with at least one R10a, a C1-C60 heteroarylene group that is unsubstituted or substituted with at least one R10a, a divalent non-aromatic condensed polycyclic group that is unsubstituted or substituted with at least one R10a, or a divalent non-aromatic condensed heteropolycyclic group that is unsubstituted or substituted with at least one R10a.
In another embodiment, Li to L1 may each independently be: a single bond; or
a benzene group, a naphthalene group, a phenanthrene group, a pyrene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinazoline group, a quinoxaline group, a naphthyridine group, a benzoquinoline group, a benzoisoquinoline group, a benzoquinazoline group, a benzoquinoxaline group, a benzonaphthyridine group, a pyridoquinoline group, a pyridoisoquinoline group, a pyridoquinazoline group, a pyridoquinoxaline group, a pyridonaphthyridine group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a pyridopyrazole group, a pyridoimidazole group, a pyridoxazole group, a pyridothiazole group, a pyridopyrrole group, a pyridofuran group, or a pyridothiophene group, each unsubstituted or substituted with deuterium, a C1-C20 alkyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a phenanthrenyl group, a pyrenyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinazolinyl group, a quinoxalinyl group, a naphthyridinyl group, a benzoquinolinyl group, a benzoisoquinolinyl group, a benzoquinazolinyl group, a benzoquinoxalinyl group, a benzonaphthyridinyl group, a pyridoquinolinyl group, a pyridoisoquinolinyl group, a pyridoquinazolinyl group, a pyridoquinoxalinyl group, a pyridonaphthyridinyl group, a benzopyrazolyl group, a benzoimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, a pyridopyrazolyl group, a pyridoimidazolyl group, a pyridoxazolyl group, a pyridothiazolyl group, a pyridopyrrolyl group, a pyridofuranyl group, a pyridothiophenyl group, or any combination thereof.
In an embodiment, Ar1 to Ar13 may each independently be a C6-C60 aryl group or a C1-C60 heteroaryl group, each unsubstituted or substituted with a deuterium group.
In another embodiment, Ar1 to Ar13 may each independently be a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-cyclopentane-fluorenyl group, a spiro-cyclohexane-fluorenyl group, a spiro-fluorene-benzofluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, an indolyl group, an isoindolyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, a dibenzothiophenyla fluorenyl group, an azacarbazolyl group, a diazacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, an imidazopyridinyl group, or an imidazopyrimidinyl group, each unsubstituted or substituted with a deuterium group.
In an embodiment, R1 to R6 may each independently be:
In an embodiment, the first compound or the second compound may each independently have a deuterium substitution ratio greater than or equal to 30%.
In an embodiment, the first compound or the second compound may each independently have a deuterium substitution ratio less than or equal to 50%.
In an embodiment, the third compound may not include deuterium.
[First, Second, and Third Host Compound]
In an embodiment, the first compound may include, for example, one of Compounds 1-1 to 1-13. In an embodiment, the second compound may include one of Compounds 2-1 to 2-14. In an embodiment, the third compound may include one of Compounds 3-1 to 3-9:
According to embodiments, as the emission layer of the blue light-emitting unit of the light-emitting device includes a first host that has a deuterium substitution ratio greater than or equal to 20%, as the emission layer of the green light-emitting unit includes a mixed host of a hole transport host and an electron transport host, and as the hole transport host has a deuterium substitution ratio greater than or equal to 20%, a lifespan difference between the blue light-emitting unit and the green light-emitting unit may be reduced. In the tandem light-emitting device of the related art, as the lifespan of a green light-emitting unit is shortened by more than 20%, compared to the blue light-emitting unit, the color coordinates of white light from the tandem light-emitting device become biased towards the blue region over time. When the color coordinates of white light from the tandem light-emitting device are changed, the luminance ratio of pixels generated through a color conversion layer and a color filter layer may also change, which leads to degraded color impression of white light at a panel implemented by the tandem light-emitting device. In the light-emitting device according to the embodiments, as the blue light-emitting unit and the green light-emitting unit have a similar lifespan, color coordinates at a panel may remain constant for a long time, and the color impression may also be maintained.
[Phosphorescent Dopant]
In embodiments, the phosphorescent dopant may include at least one transition metal as a central metal.
The phosphorescent dopant may include a monodentate ligand, a bidentate ligand, a tridentate ligand, a tetradentate ligand, a pentadentate ligand, a hexadentate ligand, or any combination thereof.
The phosphorescent dopant may be electrically neutral.
In an embodiment, the phosphorescent dopant may include an organometallic compound represented by Formula 401:
In Formulae 401 and 402,
M may be a transition metal (for example, iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), gold (Au), hafnium (Hf), europium (Eu), terbium (Tb), rhodium (Rh), rhenium (Re), or thulium (Tm)),
In an embodiment, in Formula 402, X401 may be nitrogen and X402 may be carbon, or X401 and X402 may each be nitrogen.
In an embodiment, in Formula 401, when xc1 is 2 or more, two ring A401 (s) among two or more of L401 may optionally be bonded to each other via T402, which is a linking group, and two ring A402(s) among two or more of L401 may optionally be bonded to each other via T403, which is a linking group (see Compounds PD1 to PD4 and PD7). T402 and T403 may each independently be the same as described herein with respect to T401.
In Formula 401, L402 may be an organic ligand. For example, L402 may include a halogen group, a diketone group (for example, an acetylacetonate group), a carboxylic acid group (for example, a picolinate group), —C(═O), an isonitrile group, —CN group, a phosphorus group (for example, a phosphine group, a phosphite group, etc.), or any combination thereof.
The phosphorescent dopant may include, for example, one of Compounds PD1 to PD39, or any combination thereof:
[Fluorescent Dopant]
The fluorescent dopant may include an amine group-containing compound, a styryl group-containing compound, or any combination thereof.
In an embodiment, the fluorescent dopant may include a compound represented by Formula 501:
In Formula 501,
In an embodiment, in Formula 501, Ar501 may be a condensed cyclic group (for example, an anthracene group, a chrysene group, or a pyrene group) in which three or more monocyclic groups are condensed together.
In embodiments, in Formula 501, xd4 may be 2.
In an embodiment, the fluorescent dopant may include: one of Compounds FD1 to FD37; DPVBi; DPAVBi; or any combination thereof:
[Delayed Fluorescence Material]
An emission layer may include a delayed fluorescence material.
In the specification, the delayed fluorescence material may be selected from compounds capable of emitting delayed fluorescent light based on a delayed fluorescence emission mechanism.
The delayed fluorescence material included in an emission layer may serve as a host or as a dopant, depending on the types of other materials included in the emission layer.
In embodiments, a difference between a triplet energy level (eV) of the delayed fluorescence material and a singlet energy level (eV) of the delayed fluorescence material may be greater than or equal to 0 eV and less than or equal to 0.5 eV. When the difference between a triplet energy level (eV) of the delayed fluorescence material and a singlet energy level (eV) of the delayed fluorescence material satisfies the above-described range, up-conversion from the triplet state to the singlet state of the delayed fluorescence material may effectively occur, and thus, the luminescence efficiency of the light-emitting device 10 may be improved.
In embodiments, the delayed fluorescence material may include: a material including at least one electron donor (for example, a π electron-rich C3-C60 cyclic group, such as a carbazole group) and at least one electron acceptor (for example, a sulfoxide group, a cyano group, or a π electron-deficient nitrogen-containing C1-C60 cyclic group); or a material including a C8-C60 polycyclic group in which two or more cyclic groups are condensed while sharing boron (B).
Examples of a delayed fluorescence material may include at least one of Compounds DF1 to DF14:
[Quantum Dot]
An emission layer may include a quantum dot.
In the specification, a quantum dot may be a crystal of a semiconductor compound, and may include any material capable of emitting light of various emission wavelengths according to a size of the crystal.
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 a wet chemical process, a metal organic chemical vapor deposition process, a molecular beam epitaxy process, or any process similar thereto.
The wet chemical process is a method that includes mixing a precursor material with an organic solvent and growing a quantum dot particle crystal. When the crystal grows, the organic solvent naturally acts as a dispersant coordinated on the surface of the quantum dot crystal and controls the growth of the crystal so that the growth of quantum dot particles can be controlled through a process which costs less, and may be more readily performed than vapor deposition methods, such as metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE),
The quantum dot may include a Group II-VI semiconductor compound, a Group III-V semiconductor compound, a Group III-VI semiconductor compound, a Group I-III-VI semiconductor compound, a Group IV-VI semiconductor compound, a Group IV element or compound, or any combination thereof.
Examples of a Group II-VI semiconductor compound may include: a binary compound, such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, or MgS; a ternary compound, such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, or MgZnS; a quaternary compound, such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, or HgZnSTe; or any combination thereof.
Examples of a Group III-V semiconductor compound may include: a binary compound, such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, or InSb; a ternary compound, such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AINAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, or InPSb; a quaternary compound, such as GaAINP, GaAINAs, GaAINSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GalnNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, or InAlPSb; or any combination thereof. In an embodiment, a Group III-V semiconductor compound may further include a Group II element. Examples of a Group III-V semiconductor compound further including a Group II element may include InZnP, InGaZnP, InAlZnP, etc.
Examples of a Group III-VI semiconductor compound may include: a binary compound, such as GaS, GaSe, Ga2Se3, GaTe, InS, InSe, In2S3, In2Se3, or InTe; a ternary compound, such as InGaS3, or InGaSes; or any combination thereof.
Examples of a Group I-III-VI semiconductor compound may include: a ternary compound, such as AgInS, AgInS2, CuInS, CulnS2, CuGaO2, AgGaO2, or AgAIO2; or any combination thereof.
Examples of a Group IV-VI semiconductor compound may include: a binary compound, such as SnS, SnSe, SnTe, PbS, PbSe, or PbTe; a ternary compound, such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, or SnPbTe; a quaternary compound, such as SnPbSSe, SnPbSeTe, or SnPbSTe; or any combination thereof.
Examples of a Group IV element or compound may include: a single element material, such as Si or Ge; a binary compound, such as SiC or SiGe; or any combination 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.
In embodiments, the quantum dot may have a single structure in which the concentration of each element in the quantum dot is uniform, or the quantum dot may have a core-shell structure. In an embodiment, in case that the quantum dot has a core-shell structure, a material included in the core and a material included in the shell may be different from each other.
The shell of the quantum dot may serve as a protective layer that prevents chemical degeneration of the core to maintain semiconductor characteristics, and/or may serve as a charging layer that imparts electrophoretic characteristics to the quantum dot. The shell may be a single layer or a multi-layer. An interface between the core and the shell may have a concentration gradient in which the concentration of a material that is present in the shell decreases toward the core.
Examples of a shell of a quantum dot may include a metal oxide, a metalloid oxide, a non-metal oxide, a semiconductor compound, or any combination thereof. Examples of a metal oxide, a metalloid 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, or NiO; a ternary compound, such as MgAl2O4, CoFe2O4, NiFe2O4, or CoMn2O4; or any combination thereof.
Examples of a semiconductor compound may include as described herein, a Group II-VI semiconductor compound, a Group III-V semiconductor compound, a Group III-VI semiconductor compound, a Group I-III-VI semiconductor compound, a Group IV-VI semiconductor compound, or any combination thereof. For example, 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, or any combination thereof.
A full width at half maximum (FWHM) of an emission wavelength spectrum of a quantum dot may be equal to or less than about 45 nm. For example, a FWHM of an emission wavelength spectrum of a quantum dot may be equal to or less than about 40 nm. For example, a FWHM of an emission wavelength spectrum of a quantum dot may be equal to or less than about 30 nm. Within these ranges, color purity or color reproducibility may be increased. Light emitted through a quantum dot may be emitted in all directions, so that a wide viewing angle may be improved.
In embodiments, a quantum dot may be in the form of a spherical particle, a pyramidal particle, a multi-arm particle, a cubic nanoparticle, a nanotube particle, a nanowire particle, a nanofiber particle, or a nanoplate particle.
Since the energy band gap may be adjusted by controlling the size of the quantum dot, light having various wavelength bands may be obtained from a quantum dot emission layer. Accordingly, by using quantum dots of different sizes, a light-emitting device that emits light of various wavelengths may be implemented. In embodiments, the size of the quantum dot may be selected to emit red light, green light, and/or blue light. In an embodiment, the size of the quantum dot may be configured to emit white light by combination of light of various colors.
[Electron Transport Region in Light-Emitting Unit]
An electron transport region may have a structure consisting of a layer consisting of a single material, a structure consisting of a layer including different materials, or a structure including multiple layers including different materials.
An electron-transporting region may include a buffer layer, a hole-blocking layer, an electron control layer, an electron transport layer, an electron injection layer, or any combination thereof.
In embodiments, an electron transport region may have an electron transport layer/electron injection layer structure, a hole-blocking layer/electron transport layer/electron injection layer structure, an electron control layer/electron transport layer/electron injection layer structure, or a buffer layer/electron transport layer/electron injection layer structure, wherein the layers of each structure may be stacked from an emission layer in its respective stated order, but the structure of an electron transport region is not limited thereto.
In an embodiment, the electron transport region (for example, a buffer layer, a hole-blocking layer, an electron control layer, or an electron transport layer in the electron transport region) may include a metal-free compound including at least one rr electron-deficient nitrogen-containing C1-C60 cyclic group.
In an embodiment, an electron transport region may include a compound represented by Formula 601:
[Ar601]xe11-[(L601)xe1-R601]xe21 [Formula 601]
In Formula 601,
at least one of Ar601, L601, and R601 may each independently be a π electron-deficient nitrogen-containing C1-C60 cyclic group unsubstituted or substituted with at least one R10a.
In an embodiment, in Formula 601, when xe11 is 2 or more, two or more of Ar601 (s) may be linked to each other via a single bond.
In embodiments, in Formula 601, Ar601 may be an anthracene group unsubstituted or substituted with at least one R10a.
In embodiments, an electron transport region may include a compound represented by Formula 601-1:
In Formula 601-1,
In embodiments, in Formulae 601 and 601-1, xe1 and xe611 to xe613 may each independently be 0, 1, or 2.
In embodiments, an electron transport region may include one of Compounds ET1 to ET45, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq3, BAIq, TAZ, NTAZ, or any combination thereof:
A thickness of an electron transport region may be in a range of about 100 Å to about 5,000 Å. For example, a thickness of an electron transport region may be in a range of about 160 Å to about 4,000 Å. When an electron transport region includes a buffer layer, a hole-blocking layer, an electron control layer, an electron transport layer, or any combination thereof, a thickness of a buffer layer, a hole-blocking layer, or an electron control layer may each independently be in a range of about 20 Å to about 1,000 Å, and a thickness of an electron transport layer may be in a range of about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. For example, a thickness of a buffer layer, a hole blocking layer, or an electron control layer may each independently be in a range of about 30 Å to about 300 Å. For example, a thickness of an electron transport layer may be in a range of about 150 Å to about 500 Å. When the thickness of the buffer layer, the hole blocking layer, the electron control layer, the electron transport layer, and/or the electron transport region are within these ranges, satisfactory electron transporting characteristics may be obtained without a substantial increase in driving voltage.
An electron transport region (for example, an electron transport layer in the electron transport region) may further include, in addition to the materials described above, a metal-containing material.
The metal-containing material may include an alkali metal complex, an alkaline earth metal complex, or any combination thereof. A metal ion of an alkali metal complex may be a Li ion, a Na ion, a K ion, a Rb ion, or a Cs ion, and a metal ion of an alkaline earth metal complex may be a Be ion, a Mg ion, a Ca ion, a Sr ion, or a Ba ion.
A ligand coordinated with the metal ion of an alkali metal complex or an alkaline earth-metal complex may each independently include a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenylbenzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, a cyclopentadiene, or any combination thereof.
For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (LiQ) or Compound ET-D2:
An electron transport region may include an electron injection layer that facilitates the injection of electrons from the second electrode 150 or from a charge generation layer. An electron injection layer may directly contact the second electrode 150 or a charge generation layer.
An electron injection layer may have a structure consisting of a layer consisting of a single material, a structure consisting of a layer including different materials, or a structure including multiple layers including different materials.
The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof.
The alkali metal may include Li, Na, K, Rb, Cs, or any combination thereof.
The alkaline earth metal may include Mg, Ca, Sr, Ba, or any combination thereof. The rare earth metal may include Sc, Y, Ce, Tb, Yb, Gd, or any combination thereof.
The alkali metal-containing compound, the alkaline earth metal-containing compound, and the rare earth metal-containing compound may be oxides, halides (for example, fluorides, chlorides, bromides, or iodides), or tellurides of the alkali metal, the alkaline earth metal, and the rare earth metal, or any combination thereof.
The alkali metal-containing compound may include: an alkali metal oxide, such as Li2O, Cs2O, or K2O; an alkali metal halide, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, or KI; or any combination thereof. The alkaline earth metal-containing compound may include an alkaline earth metal compound, such as BaO, SrO, CaO, BaxSri-xO (wherein x is a real number satisfying the condition of 0<x<1), BaxCa1-xO (wherein x is a real number satisfying the condition of 0<x<1), or the like. The rare earth metal-containing compound may include YbF3, ScF3, Sc2O3, Y2O3, Ce2O3, GdF3, TbF3, YbI3, Scl3, Tbl3, or any combination thereof. In embodiments, the rare earth metal-containing compound may include a lanthanide metal telluride. Examples of a lanthanide metal telluride may include LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, La2Te3, Ce2Te3, Pr2Te3, Nd2Te3, Pm2Te3, Sm2Te3, Eu2Te3, Gd2Te3, Tb2Te3, Dy2Te3, Ho2Te3, Er2Te3, Tm2Te3, Yb2Te3, and Lu2Tes.
The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include: an alkali metal ion, an alkaline earth metal ion, or a rare earth metal ion; and a ligand bonded to the metal ion (for example, a hydroxyquinoline, a hydroxyisoquinoline, a hydroxybenzoquinoline, a hydroxyacridine, a hydroxyphenanthridine, a hydroxyphenyloxazole, a hydroxyphenylthiazole, a hydroxyphenyloxadiazole, a hydroxyphenylthiadiazole, a hydroxyphenylpyridine, a hydroxyphenyl benzimidazole, a hydroxyphenylbenzothiazole, a bipyridine, a phenanthroline, a cyclopentadiene, or any combination thereof).
In an embodiment, an electron injection layer may consist of an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof, as described above. In embodiments, an electron injection layer may further include an organic material (for example, a compound represented by Formula 601).
In embodiments, an electron injection layer may consist of an alkali metal-containing compound (for example, an alkali metal halide); or an electron injection layer may consist of an alkali metal-containing compound (for example, an alkali metal halide), and an alkali metal, an alkaline earth metal, a rare earth metal, or any combination thereof. For example, an electron injection layer may be a KI:Yb co-deposited layer, an RbI:Yb co-deposited layer, a LiF:Yb co-deposited layer, or the like.
When an electron injection layer further includes an organic material, an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof may be uniformly or non-uniformly dispersed in a matrix including the organic material.
A thickness of an electron injection layer may be in a range of about 1 Å to about 100 Å. For example, a thickness of an electron injection layer may be in a range of about 3 Å to about 90 Å. When the thickness of an electron injection layer is within the ranges described above, satisfactory electron injection characteristics may be obtained without a substantial increase in driving voltage.
[Second Electrode 150]
The second electrode 150 may be located on the interlayer 130 having a structure as described above. The second electrode 150 may be a cathode, which is an electron injection electrode. A material for forming the second electrode 150 may be a material having a low-work function, such as a metal, an alloy, an electrically conductive compound, or any combination thereof.
The second electrode 150 may include lithium (Li), silver (Ag), magnesium (Mg), aluminum (AI), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ytterbium (Yb), silver-ytterbium (Ag—Yb), ITO, IZO, or any combination thereof. The second electrode 150 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.
The second electrode 150 may have a single-layered structure or a multi-layered structure.
[Capping Layer]
The light-emitting device 10 may include a first capping layer outside the first electrode 110, and/or a second capping layer outside the second electrode 150. For example, the light-emitting device 10 may have a structure in which the first capping layer, the first electrode 110, the interlayer 130, and the second electrode 150 are stacked in this stated order, a structure in which the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are stacked in this stated order, or a structure in which the first capping layer, the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are stacked in this stated order.
Light generated in an emission layer of the interlayer 130 of the light-emitting device 10 may be extracted toward the outside through the first electrode 110, which may be a semi-transmissive electrode or a transmissive electrode, and through the first capping layer. Light generated in an emission layer of the interlayer 130 of the light-emitting device 10 may be extracted toward the outside through the second electrode 150, which may be a semi-transmissive electrode or a transmissive electrode, and through the second capping layer.
The first capping layer and the second capping layer may each increase external emission efficiency according to the principle of constructive interference. Accordingly, the light extraction efficiency of the light-emitting device 10 may be increased, so that the luminescence efficiency of the light-emitting device 10 may be improved.
The first capping layer and the second capping layer may each include a material having a refractive index greater than or equal to about 1.6 (with respect to a wavelength of about 589 nm).
The first capping layer and the second capping layer may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or an organic-inorganic composite capping layer including an organic material and an inorganic material.
At least one of the first capping layer and the second capping layer may each independently include a carbocyclic compound, a heterocyclic compound, an amine group-containing compound, a porphine derivative, a phthalocyanine derivative, a naphthalocyanine derivative, an alkali metal complex, an alkaline earth metal complex, or any combination thereof. The carbocyclic compound, the heterocyclic compound, and the amine group-containing compound may be optionally substituted with a substituent including O, N, S, Se, Si, F, Cl, Br, I, or any combination thereof.
In embodiments, at least one of the first capping layer and the second capping layer may each independently include an amine group-containing compound.
In embodiments, at least one of the first capping layer and the second capping layer may each independently include a compound represented by Formula 201, a compound represented by Formula 202, or any combination thereof.
In embodiments, at least one of the first capping layer and the second capping layer may each independently include one of Compounds HT28 to HT33, one of Compounds CP1 to CP6, p-NPB, or any combination thereof:
[Electronic Apparatus]
The light-emitting device may be included in various electronic apparatuses. For example, the electronic apparatus including the light-emitting device may be a light-emitting apparatus, an authentication apparatus, or the like.
The electronic apparatus (for example, a light-emitting apparatus) may further include, in addition to the light-emitting device, a color filter, a color conversion layer, or a color filter and a color conversion layer. The color filter and/or the color conversion layer may be located in at least one direction in which light emitted from the light-emitting device travels. In embodiments, the light emitted from the light-emitting device may be blue light or white light. The light-emitting device may be a light-emitting device as described herein. In embodiments, the color conversion layer may include a quantum dot. The quantum dot may be, for example, a quantum dot as described herein.
The electronic apparatus may include a first substrate. The first substrate may include subpixels, the color filter may include color filter areas respectively corresponding to the subpixels, and the color conversion layer may include color conversion areas respectively corresponding to the subpixels.
A pixel-defining film may be located between the subpixels to define each subpixel.
The color filter may further include color filter areas and light-shielding patterns located between the color filter areas, and the color conversion layer may further include color conversion areas and light-shielding patterns located between the color conversion areas.
The color filter areas (or the color conversion areas) may include a first area emitting first color light, a second area emitting second color light, and/or a third area emitting third color light, wherein the first color light, the second color light, and/or the third color light may have different maximum emission wavelengths from one another. For example, the first color light may be red light, the second color light may be green light, and the third color light may be blue light. In embodiments, the color filter areas (or the color conversion areas) may include quantum dots. For example, the first area may include red quantum dots, the second area may include green quantum dots, and the third area may not include quantum dots. The quantum dot may be a quantum as described herein. The first area, the second area, and/or the third area may each further include a scatterer.
In an embodiment, the light-emitting device may emit first light, the first area may absorb the first light to emit first-first color light, the second area may absorb the first light to emit second-first color light, and the third area may absorb the first light to emit third-first color light. In this regard, the first-first color light, the second-first color light, and the third-first color light may have different maximum emission wavelengths from one another. For example, the first light may be blue light, the first-first color light may be red light, the second-first color light may be green light, and the third-first color light may be blue light.
The electronic apparatus may further include a thin-film transistor, in addition to the light-emitting device as described above. The thin-film transistor may include a source electrode, a drain electrode, and an active layer, wherein any one of the source electrode and the drain electrode may be electrically connected to any one of the first electrode and the second electrode of the light-emitting device.
The thin-film transistor may further include a gate electrode, a gate insulating film, or the like.
The active layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, or the like.
The electronic apparatus may further include a sealing portion for sealing the light-emitting device. The sealing portion may be located between the color filter and/or the color conversion layer, and the light-emitting device. The sealing portion may allow light from the light-emitting device to be extracted to the outside, and may simultaneously prevent ambient air and moisture from penetrating into the light-emitting device. The sealing portion may be a sealing substrate including a transparent glass substrate or a plastic substrate. The sealing portion may be a thin-film encapsulation layer including an organic layer and/or an inorganic layer. When the sealing portion is a thin-film encapsulation layer, the electronic apparatus may be flexible.
Various functional layers may be further included on the sealing portion, in addition to the color filter and/or the color conversion layer, according to the use of the electronic apparatus. Examples of a functional layer may include a touch screen layer, a polarizing layer, and the like. The touch screen layer may be a pressure-sensitive touch screen layer, a capacitive touch screen layer, or an infrared touch screen layer. The authentication apparatus may be, for example, a biometric authentication apparatus that authenticates an individual by using biometric information of a living body (for example, fingertips, pupils, etc.).
The authentication apparatus may further include, in addition to the light-emitting device as described above, a biometric information collector.
The electronic apparatus may be applied to various displays, light sources, lighting, personal computers (for example, a mobile personal computer), mobile phones, digital cameras, electronic organizers, electronic dictionaries, electronic game machines, medical instruments (for example, electronic thermometers, sphygmomanometers, blood glucose meters, pulse measurement devices, pulse wave measurement devices, electrocardiogram displays, ultrasonic diagnostic devices, or endoscope displays), fish finders, various measuring instruments, meters (for example, meters for a vehicle, an aircraft, and a vessel), projectors, and the like.
[Electronic Equipment]
The light-emitting device may be included in various electronic equipment.
For example, the electronic equipment including the light-emitting device may be a flat panel display, a curved display, a computer monitor, a medical monitor, a television, a billboard, an indoor light, an outdoor light, a signal light, a head-up display, a fully transparent display, a partially transparent display, a flexible display, a rollable display, a foldable display, a stretchable display, a laser printer, a telephone, a mobile phone, a tablet, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a micro display, a three-dimensional (3D) display, a virtual reality display, an augmented reality display, a vehicle, a video wall including multiple displays tiled together, a theater screen, a stadium screen, a phototherapy device, or a signboard.
The light-emitting device may have excellent effects in terms of luminescence efficiency and long lifespan, and thus the electronic equipment including the light-emitting device may have characteristics, such as high luminance, high resolution, and low power consumption.
[Description of
The electronic apparatus (for example a light-emitting apparatus) of
The substrate 100 may be a flexible substrate, a glass substrate, or a metal substrate. A buffer layer 210 may be located on the substrate 100. The buffer layer 210 may prevent penetration of impurities through the substrate 100 and may provide a flat surface on the substrate 100.
A TFT may be located on the buffer layer 210. The TFT may include an active layer 220, a gate electrode 240, a source electrode 260, and a drain electrode 270.
The active layer 220 may include an inorganic semiconductor such as silicon or polysilicon, an organic semiconductor, or an oxide semiconductor, and may include a source region, a drain region, and a channel region.
A gate insulating film 230 for insulating the active layer 220 from the gate electrode 240 may be located on the active layer 220, and the gate electrode 240 may be located on the gate insulating film 230.
An interlayer insulating film 250 may be located on the gate electrode 240. The interlayer insulating film 250 may be located between the gate electrode 240 and the source electrode 260 to insulate the gate electrode 240 from the source electrode 260 and between the gate electrode 240 and the drain electrode 270 to insulate the gate electrode 240 from the drain electrode 270.
The source electrode 260 and the drain electrode 270 may be located on the interlayer insulating film 250. The interlayer insulating film 250 and the gate insulating film 230 may be formed to expose a source region and a drain region of the active layer 220, and the source electrode 260 and the drain electrode 270 may respectively contact the exposed portions of the source region and the drain region of the active layer 220.
The TFT is electrically connected to a light-emitting device to drive the light-emitting device, and is covered and protected by a passivation layer 280. The passivation layer 280 may include an inorganic insulating film, an organic insulating film, or any combination thereof. A light-emitting device is provided on the passivation layer 280. The light-emitting device may include a first electrode 110, an interlayer 130, and a second electrode 150.
The first electrode 110 may be located on the passivation layer 280. The passivation layer 280 may not completely cover the drain electrode 270 and may expose a portion of the drain electrode 270. The first electrode 110 may be electrically connected to the exposed portion of the drain electrode 270.
A pixel defining layer 290 including an insulating material may be located on the first electrode 110. The pixel defining layer 290 may expose a region of the first electrode 110, and an interlayer 130 may be formed in the exposed region of the first electrode 110. The pixel defining layer 290 may be a polyimide or polyacrylic organic film. Although not shown in
The second electrode 150 may be located on the interlayer 130, and a capping layer 170 may be further included on the second electrode 150. The capping layer 170 may be formed to cover the second electrode 150.
The encapsulation portion 300 may be located on the capping layer 170. The encapsulation portion 300 may be located on a light-emitting device to protect the light-emitting device from moisture and/or oxygen. The encapsulation portion 300 may include: an inorganic film including silicon nitride (SiNx), silicon oxide (SiOx), indium tin oxide, indium zinc oxide, or any combination thereof; an organic film including polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyldisiloxane, an acrylic resin (for example, polymethyl methacrylate, polyacrylic acid, or the like), an epoxy-based resin (for example, aliphatic glycidyl ether (AGE), or the like), or any combination thereof; or any combination of the inorganic films and the organic films.
The electronic apparatus (for example, a light-emitting apparatus) of
[Description of
The electronic equipment 1 which may be an apparatus that displays a moving image or still image, may be not only a portable electronic equipment, such as a mobile phone, a smartphone, a tablet personal computer (PC), a mobile communication terminal, an electronic notebook, an electronic book, a portable multimedia player (PMP), a navigation device, or an ultra-mobile PC (UMPC), but may also be various products, such as a television, a laptop computer, a monitor, a billboard, or an Internet of things (IOT). The electronic equipment 1 may be such a product as described above or a part thereof.
In an embodiment, the electronic equipment 1 may be a wearable device, such as a smart watch, a watch phone, a glasses-type display, or a head mounted display (HMD), or a part of the wearable device. However, embodiments are not limited thereto.
For example, the electronic equipment 1 may be a dashboard of a vehicle, a center fascia of a vehicle, a center information display arranged on a dashboard of a vehicle, a room mirror display replacing a side mirror of a vehicle, an entertainment display for the rear seat of a vehicle, a display arranged on the back of the front seat, or a head up display (HUD) installed in the front of a vehicle or projected on a front window glass, or a computer-generated hologram augmented-reality head up display (CGH AR HUD). For convenience of explanation,
The electronic equipment 1 may include a display area DA and a non-display area NDA outside the display area DA. A display device may implement an image through a two-dimensional array of pixels that are arranged in the display area DA.
The non-display area NDA is an area that does not display an image, and may surround the display area DA. A driver for providing electrical signals or power to display devices arranged in the display area DA may be arranged in the non-display area NDA. A pad, which is an area to which an electronic element or a printed circuit board may be electrically connected, may be arranged in the non-display area NDA.
In the electronic equipment 1, a length in an x-axis direction and a length in a y-axis direction may be different from each other. In an embodiment, as shown in
[Manufacturing Method]
Respective layers included in a hole transport region, an emission layer, and respective layers included in an electron transport region may be formed in a selected region by using one or more suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, and laser-induced thermal imaging.
When layers constituting a hole transport region, an emission layer, and layers constituting an electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature of about 100° C. to about 500° C., a vacuum degree of about 10−8 torr to about 10−3 torr, and a deposition speed of about 0.01 Å/sec to about 100 Å/sec, depending on a material to be included in a layer to be formed and the structure of a layer to be formed.
When layers constituting a hole transport region, an emission layer, and layers constituting an electron transport region are formed by spin coating, the spin coating may be performed at a coating speed of about 2,000 rpm to about 5,000 rpm and at a heat treatment temperature of about 80° C. to about 200° C. by taking into account a material to be included in a layer to be formed and the structure of a layer to be formed.
The term “C3-C60 carbocyclic group” as used herein may be a cyclic group consisting of carbon atoms as the only ring-forming atoms and having three to sixty carbon atoms, and the term “C1-C60 heterocyclic group” as used herein may be a cyclic group that has one to sixty carbon atoms and further has, in addition to a carbon atom, at least one heteroatom as a ring-forming atom. The C3-C60 carbocyclic group and the C1-C60 heterocyclic group may each be a monocyclic group consisting of one ring or a polycyclic group in which two or more rings are condensed with each other. For example, a C1-C60 heterocyclic group may have 3 to 61 ring-forming atoms.
The term “cyclic group” as used herein may be a C3-C60 carbocyclic group or a C1-C60 heterocyclic group.
The term “π electron-rich C3-C60 cyclic group” as used herein may be a cyclic group that has three to sixty carbon atoms and may not include *—N═*′ as a ring-forming moiety, and the term “π electron-deficient nitrogen-containing C1-C60 cyclic group” as used herein may be a heterocyclic group that has one to sixty carbon atoms and may include *—N═*′ as a ring-forming moiety.
In embodiments,
the T2 group may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a tetrazine group, a pyrrolidine group, an imidazolidine group, a dihydropyrrole group, a piperidine group, a tetrahydropyridine group, a dihydropyridine group, a hexahydropyrimidine group, a tetrahydropyrimidine group, a dihydropyrimidine group, a piperazine group, a tetrahydropyrazine group, a dihydropyrazine group, a tetrahydropyridazine group, or a dihydropyridazine group.
the T3 group may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, or a borole group, and
the T4 group may be a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, or a tetrazine group.
The terms “cyclic group”, “C3-C60 carbocyclic group”, “C1-C60 heterocyclic group”, “π electron-rich C3-C60 cyclic group”, or “π electron-deficient nitrogen-containing C1-C60 cyclic group” as used herein may each be a group condensed to any cyclic group, a monovalent group, or a polyvalent group (for example, a divalent group, a trivalent group, a tetravalent group, etc.) according to the structure of a formula for which the corresponding term is used. For example, a “benzene group” may be a benzo group, a phenyl group, a phenylene group, or the like, which may be readily understood by one of ordinary skill in the art according to the structure of a formula including the “benzene group.”
Examples of a monovalent C3-C60 carbocyclic group or a monovalent C1-C60 heterocyclic group may include a C3-C10 cycloalkyl group, a C1-C10 heterocycloalkyl group, a C3-Cia cycloalkenyl group, a C1-C10 heterocycloalkenyl group, a C6-C60 aryl group, a C1-C60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group. Examples of a divalent C3-C60 carbocyclic group or a divalent C1-C60 heterocyclic group may include a C3-C1 cycloalkylene group, a C1-C10 heterocycloalkylene group, a C3-C1 cycloalkenylene group, a C1-C10 heterocycloalkenylene group, a C6-C60 arylene group, a C1-C60 heteroarylene group, a divalent non-aromatic condensed polycyclic group, and a divalent non-aromatic condensed heteropolycyclic group.
The term “C1-C60 alkyl group” as used herein may be a linear or branched aliphatic hydrocarbon monovalent group that has one to sixty carbon atoms, and examples thereof may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, and a tert-decyl group. The term “C1-C60 alkylene group” as used herein may be a divalent group having a same structure as the C1-C60 alkyl group.
The term “C2-C60 alkenyl group” as used herein may be a monovalent hydrocarbon group having at least one carbon-carbon double bond in the middle or at a terminus of a C2-C60 alkyl group, and examples thereof may include an ethenyl group, a propenyl group, and a butenyl group. The term “C2-C60 alkenylene group” as used herein may be a divalent group having a same structure as the C2-C60 alkenyl group.
The term “C2-C60 alkynyl group” as used herein may be a monovalent hydrocarbon group having at least one carbon-carbon triple bond in the middle or at a terminus of a C2-C60 alkyl group, and examples thereof may include an ethynyl group, a propynyl group, and the like. The term “C2-C60 alkynylene group” as used herein may be a divalent group having a same structure as the C2-C60 alkynyl group.
The term “C1-C60 alkoxy group” as used herein may be a monovalent group represented by —O(A101) (wherein A101 may be a C1-C60 alkyl group), and examples thereof may include a methoxy group, an ethoxy group, and an isopropyloxy group.
The term “C3-C10 cycloalkyl group” as used herein may be a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and examples thereof may include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl group (or bicyclo[2.2.1]heptyl group), a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, and a bicyclo[2.2.2]octyl group. The term “C3-C10 cycloalkylene group” as used herein may be a divalent group having a same structure as the C3-C10 cycloalkyl group.
The term “C1-C10 heterocycloalkyl group” as used herein may be a monovalent cyclic group of 1 to 10 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and examples thereof may include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C1-C1 heterocycloalkylene group” as used herein may be a divalent group having a same structure as the C1-C1 heterocycloalkyl group.
The term “C3-C10 cycloalkenyl group” as used herein may be a monovalent cyclic group that has three to ten carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and examples thereof may include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C3-C10 cycloalkenylene group” as used herein may be a divalent group having a same structure as the C3-C10 cycloalkenyl group.
The term “C1-C1 heterocycloalkenyl group” as used herein may be a monovalent cyclic group of 1 to 10 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and having at least one carbon-carbon double bond in the cyclic structure thereof. Examples of a C1-C1 heterocycloalkenyl group may include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C1-C1 heterocycloalkenylene group” as used herein may be a divalent group having a same structure as the C1-C1 heterocycloalkenyl group.
The term “C6-C60 aryl group” as used herein may be a monovalent group having a carbocyclic aromatic system of 6 to 60 carbon atoms, and the term “C6-C60 arylene group” as used herein may be a divalent group having a carbocyclic aromatic system of 6 to 60 carbon atoms. Examples of a C6-C60 aryl group may include a phenyl group, a pentalenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a heptalenyl group, a naphthacenyl group, a picenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, and an ovalenyl group. When the C6-C60 aryl group and the C6-C60 arylene group each include two or more rings, the respective rings may be condensed with each other.
The term “C1-C60 heteroaryl group” as used herein may be a monovalent group having a heterocyclic aromatic system of 1 to 60 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms. The term “C1-C60 heteroarylene group” as used herein may be a divalent group having a heterocyclic aromatic system of 1 to 60 carbon atoms, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms. Examples of a C1-C6a heteroaryl group may include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, a benzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinyl group, a phthalazinyl group, and a naphthyridinyl group. When the C1-C60 heteroaryl group and the C1-C60 heteroarylene group each include two or more rings, the respective rings may be condensed with each other.
The term “monovalent non-aromatic condensed polycyclic group” as used herein may be a monovalent group (for example, having 8 to 60 carbon atoms) having two or more rings condensed to each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure. Examples of a monovalent non-aromatic condensed polycyclic group may include an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, and an indeno anthracenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein may be a divalent group having a same structure as the monovalent non-aromatic condensed polycyclic group as described above.
The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein may be a monovalent group (for example, having 1 to 60 carbon atoms) having two or more rings condensed to each other, further including, in addition to carbon atoms, at least one heteroatom, as ring-forming atoms, and having non-aromaticity in its entire molecular structure. Examples of a monovalent non-aromatic condensed heteropolycyclic group may include a pyrrolyl group, a thiophenyl group, a furanyl group, an indolyl group, a benzoindolyl group, a naphthoindolyl group, an isoindolyl group, a benzoisoindolyl group, a naphthoisoindolyl group, a benzosilolyl group, a benzothiophenyl group, a benzofuranyl group, a carbazolyl group, a dibenzosilolyl group, a dibenzothiophenyl group, a dibenzofuranyl group, an azacarbazolyl group, an azafluorenyl group, an azadibenzosilolyl group, an azadibenzothiophenyl group, an azadibenzofuranyl group, a pyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolyl group, an oxazolyl group, an isoxazolyl group, a thiazolyl group, an isothiazolyl group, an oxadiazolyl group, a thiadiazolyl group, a benzopyrazolyl group, a benzimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, a benzoxadiazolyl group, a benzothiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an imidazotriazinyl group, an imidazopyrazinyl group, an imidazopyridazinyl group, an indenocarbazolyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a benzosilolocarbazolyl group, a benzoindolocarbazolyl group, a benzocarbazolyl group, a benzonaphthofuranyl group, a benzonaphthothiophenyl group, a benzonaphtho silolyl group, a benzofurodibenzofuranyl group, a benzofurodibenzothiophenyl group, and a benzothienodibenzothiophenyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein may be a divalent group having a same structure as the monovalent non-aromatic condensed heteropolycyclic group as described above.
The term “C6-C60 aryloxy group” as used herein may be a group represented by —O(A102) (wherein A102 may be a C6-C60 aryl group), and the term “C6-C60 arylthio group” as used herein may be a group represented by —S(A103) (wherein A103 may be a C6-C60 aryl group).
The term “C7-C60 arylalkyl group” as used herein may be a group represented by -(A104)(A105) (wherein A104 may be a C1-C54 alkylene group, and A105 may be a C6-C59 aryl group), and the term “C2-C60 heteroarylalkyl group” as used herein may be a group represented by -(A106)(A107) (wherein A106 may be a C1-C59 alkylene group, and A107 may be a C1-C59 heteroaryl group).
In the specification, the group “R10a” may be:
In the specification, Q1 to Q3, Q11 to Q13, Q21 to Q23, and Q31 to Q33 may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C1-C60 alkyl group; a C2-C60 alkenyl group; a C2-C60 alkynyl group; a C1-C60 alkoxy group; or a C3-C60 carbocyclic group, a C1-C60 heterocyclic group, a C7-C60 arylalkyl group, or a C2-C60 heteroarylalkyl group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C1-C60 alkyl group, a C1-C60 alkoxy group, a phenyl group, a biphenyl group, or any combination thereof.
The term “heteroatom” as used herein may be any atom other than a carbon atom or a hydrogen atom. Examples of a heteroatom may include O, S, N, P, Si, B, Ge, Se, or any combination thereof.
The term “third-row transition metal” as used herein may include hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), or the like.
In the specification, the term “Ph” refers to a phenyl group, the term “Me” refers to a methyl group, the term “Et” refers to an ethyl group, the terms “tert-Bu” or “But” each refer to a tert-butyl group, and the term “OMe” refers to a methoxy group.
The term “biphenyl group” as used herein may be a “phenyl group substituted with a phenyl group.” For example, the “biphenyl group” may be a substituted phenyl group having a C6-C60 aryl group as a substituent.
The term “terphenyl group” as used herein may be a “phenyl group substituted with a biphenyl group”. For example, the “terphenyl group” may be a substituted phenyl group having, as a substituent, a C6-C60 aryl group substituted with a C6-C60 aryl group.
The symbols * and *′ as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula or moiety.
In the specification, the terms “x-axis”, “y-axis”, and “z-axis” are not limited to three axes in an orthogonal coordinate system (for example a Cartesian coordinate system), and may be interpreted in a broader sense than the aforementioned three axes in an orthogonal coordinate system. For example, the x-axis, y-axis, and z-axis may be axes that are orthogonal to each other, or may be axes that are in different directions that are not orthogonal to each other.
The device lifespan according to the deuterium substitution ratio of the hole transport host of the green emission layer and the host of the blue emission layer was measured.
An ITO glass substrate was cut to a size of 50 mm×50 mmx 0.5 mm, ultrasonically cleaned with isopropyl alcohol and pure water each for 10 minutes, and cleaned by irradiation of ultraviolet rays and exposure to ozone for 10 minutes. The ITO glass substrate was loaded onto a vacuum deposition apparatus. After vacuum depositing HAT-CN on the substrate to form a hole injection layer having a thickness of 50 Å, NPB was vacuum deposited thereon to form a hole transport layer having a thickness of 300 Å. Compound BH-C1 as a host and Compound FD37 as a dopant (3 wt %) were co-deposited on the hole transport layer to form an emission layer having a thickness of 200 Å. TPM-TAZ and Liq were deposited on the emission layer to from an electron transport layer having a thickness of 200 Å, and Ag and Mg were deposited thereon at the weight ratio of 9:1 to from a cathode having a thickness of 100 Å. The deuterium substitution ratio of the host of the blue emission layer in Experimental Example 1 was 0%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that Compound 1-1 was used as an emission layer host instead of Compound BH-C1. The deuterium substitution ratio of the host of the blue emission layer in Experimental Example 2 was 11%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that Compound 1-2 was used as an emission layer host instead of Compound BH-C1. The deuterium substitution ratio of the host of the blue emission layer in Experimental Example 3 was 18%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that Compound 1-3 was used as an emission layer host instead of Compound BH-C1. The deuterium substitution ratio of the host of the blue emission layer in Experimental Example 4 was 32%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that Compound 1-4 was used as an emission layer host instead of Compound BH-C1. The deuterium substitution ratio of the host of the blue emission layer in Experimental Example 5 was 50%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that hole transport Compound GHH-C1 as a host and Compound DP40 as a dopant (6 wt %) were co-deposited on a hole transport layer to form an emission layer having a thickness of 250 Å. The deuterium substitution ratio of each of the hole transport host of the green emission layer and the electron transport host were 0%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that Compound 2-1 was used as a hole transport host of an emission layer instead of Compound GHH-C1. The deuterium substitution ratio of the hole transport host of the green emission layer in Experimental Example 7 was 11%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that Compound 2-2 was used as a hole transport host of an emission layer instead of Compound GHH-C1. The deuterium substitution ratio of the hole transport host of the green emission layer in Experimental Example 8 was 18%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that Compound 2-3 was used as a hole transport host of an emission layer instead of Compound GHH-C1. The deuterium substitution ratio of the hole transport host of the green emission layer in Experimental Example 9 was 28%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that Compound 2-4 was used as a hole transport host of an emission layer instead of Compound GHH-C1. The deuterium substitution ratio of the hole transport host of the green emission layer in Experimental Example 10 was 36%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that Compound 2-5 was used as a hole transport host of an emission layer instead of Compound GHH-C1. The deuterium substitution ratio of the hole transport host of the green emission layer in Experimental Example 11 was 50%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that GEH-C1 was used as an electron transport host of an emission layer instead of Compound 3-1. The deuterium substitution ratio of the electron transport host of the green emission layer in Experimental Example 12 was 17%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that GEH-C2 was used as an electron transport host of an emission layer instead of Compound 3-1. The deuterium substitution ratio of the electron transport host of the green emission layer in Experimental Example 13 was 30%.
The light-emitting device was manufactured in the same manner as in Experimental Example 1, except that GEH-C3 was used as an electron transport host of an emission layer instead of Compound 3-1. The deuterium substitution ratio of the hole transport host of the green emission layer in Experimental Example 14 was 63%.
Tables 1 to 3 show the emission layer hosts used in the light-emitting devices of Experimental Examples 1 to 14.
The lifespan of the light-emitting devices of Experimental Examples 1 to 14 are compared in Tables 4 and 5, and illustrated in
With reference to
Hereinafter, with reference to the Examples, the manufacture and evaluation of the light-emitting devices will be described in detail.
An ITO/Ag/ITO glass substrate was cut to a size of 50 mm×50 mmx 0.5 mm, ultrasonically cleaned with isopropyl alcohol and pure water each for 10 minutes, and cleaned by irradiation of ultraviolet rays and exposure to ozone for 10 minutes. The ITO glass substrate was loaded onto a vacuum deposition apparatus. After vacuum depositing HAT-CN on the substrate to form a hole injection layer having a thickness of 50 Å, NPB was vacuum deposited thereon to from a hole transport layer having a thickness of 300 Å. Compound 1-2 as a host and Compound FD37 as a dopant (3 wt %) were co-deposited on the hole transport layer to form an emission layer having a thickness of 200 Å, and TPM-TAZ and Liq were deposited on the emission layer to form an electron transport layer having a thickness of 200 Å, thereby forming the first light-emitting unit (blue). BCP and Li were co-deposited at the weight ratio of 99:1 on the first light-emitting unit to form an n-type charge generation layer having a thickness of 150 Å, and HAT-CN was deposited on the n-type charge generation layer to form a p-type charge generation layer having a thickness of 50 Å, thereby forming the first charge generation layer.
The second light-emitting unit was formed on the first charge generation layer in the same manner as used to form the first light-emitting unit, and the second charge generation layer was formed in the same manner as used to form the first charge generation layer. The same method was used to form the third light-emitting unit and the third charge generation layer. The fourth light-emitting unit was formed in the same manner as used to form the first light-emitting unit, except that Compound 2-2 and Compound 3-1 (weight ratio of 7:3) used as a host and Compound PD25 (6 wt %) was used as a dopant were co-deposited to form an emission layer having a thickness of 250 Å.
Ag and Mg were deposited on the fourth light-emitting unit at the weight ratio of 9:1 to form a cathode electrode having a thickness of 100 Å, thereby manufacturing the light-emitting device.
The deuterium substitution ratio of the emission layer host of the blue light-emitting unit in Example 1 was 18%, and the deuterium substitution ratio of the hole transport host of the emission layer of the green light-emitting unit was 18%.
The light-emitting device was manufactured in the same manner as in Example 1, except that Compound 1-3 was used as a blue emission layer host, and Compound 2-4 was used as a hole transport host of the green emission layer. The deuterium substitution ratio of the emission layer host of the blue light-emitting unit in Example 2 was 32%, and the deuterium substitution ratio of the hole transport host of the emission layer of the green light-emitting unit was 36%.
The light-emitting device was manufactured in the same manner as in Example 1, except that Compound 1-3 was used as a blue emission layer host, and Compound 2-5 was used as a hole transport host of the green emission layer. The deuterium substitution ratio of the emission layer host of the blue light-emitting unit in Example 3 was 32%, and the deuterium substitution ratio of the hole transport host of the emission layer of the green light-emitting unit was 50%.
The light-emitting device was manufactured in the same manner as in Example 1, except that Compound GHH-C1 which is not substituted with deuterium was used as a hole transport host of the green emission layer.
The light-emitting device was manufactured in the same manner as in Example 1, except that Compound BH-C1 which is not substituted with deuterium was used as a host of the blue emission layer.
The light-emitting device was manufactured in the same manner as in Example 1, except that Compound BH-C1 which is not substituted with deuterium was used as a host of the blue emission layer, and Compound GHH-C1 which is not substituted with deuterium was used as a hole transport host of the green emission layer:
The driving voltage, current efficiency, lifespan, and change in CIE color coordinate of the light-emitting devices manufactured according to Examples 1 to 3 and Comparative Examples 1 to 3 were measured by using Keithley SMU 236 and a luminance meter PR650, and results thereof are shown in Table 6. The lifespan (T80) is a period of time that was taken until the luminance (@400nit) was reduced to 80% of initial luminance (100%) after a light-emitting device was driven. The change in ClE color coordinate refers to a change amount between the CIE color coordinate measured when the light-emitting device has been driven for 1000 hours and the initially measured CIE color coordinate. The color coordinate change amount was calculated with respect to the color coordinate (u′, v′) according to (([u′(initial time)]-[u′(1000 hours)]){circumflex over ( )}2+([v′(initial time)]-[v′(1000 hours)]){circumflex over ( )}2){circumflex over ( )}0.5. The color coordinate change amount over time in Examples 1 to 3 and Comparative Example 1 is shown in
With reference to Table 6 and
The change in luminance per color according to time of the light-emitting devices in Comparative Example 1 and Examples 1, 2 is shown in
According to embodiments, a light-emitting device includes light-emitting units having excellent lifespan characteristics and less lifespan difference among the light-emitting units, leading to better color reproducibility.
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 purpose of limitation. In some instances, as would be apparent by 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 |
|---|---|---|---|
| 10-2022-0099992 | Aug 2022 | KR | national |
