LIGHT-EMITTING DEVICE

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0028266, filed on Mar. 12, 2019, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.

BACKGROUND
1. Field

One or more embodiments relate to a light-emitting device.

2. Description of the Related Art

Light-emitting devices may include an anode, a cathode, and an emission layer therebetween. Holes provided from the anode and electrons provided from the cathode recombine in the emission layer to produce excitons. These excitons transit (e.g., transition or relax) from an excited state to a ground state, thereby generating light.

Light-emitting devices may be driven with a low voltage, may be implemented to be lightweight and thin, and may have excellent characteristics in terms of viewing angle, contrast, and response speed. Therefore, the application range of light-emitting devices has expanded from personal portable devices such as MP3 players or mobile phones to televisions (TVs).

SUMMARY

In a light-emitting device in which a common layer of the related art is applied, two emission layers having different colors are stacked, and an intermediate layer is inserted between the two emission layers so as to prevent or reduce color mixing.

The intermediate layer functions as a hole injection layer (HIL) and a hole transport layer (HTL) of a single device. However, because the intermediate layer is in direct contact with the emission layer, an auxiliary layer in the single device is absent. Furthermore, due to the absence of the auxiliary layer, a driving voltage may be increased by a high hole injection barrier, and electrons entering from the emission layer to the intermediate layer may not be blocked, thereby causing color mixing and a reduction in lifespan.

In addition, because the common layer is present, luminance varies by angle due to the difference in resonance distance between the two different emission layers, as compared with a case where resonances are identical to each other. Thus, it is difficult to secure a viewing angle.

Aspects of embodiments of the present disclosure provide a light-emitting device in which a driving voltage is reduced and luminance is increased.

Additional aspects of embodiments 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 presented embodiments.

An aspect of an embodiment of the present disclosure provides a light-emitting device including:

a plurality of first electrodes respectively in a first sub-pixel, a second sub-pixel, and a third sub-pixel;

a second electrode facing the plurality of first electrodes;

a first emission layer in the first sub-pixel and configured to emit a first color light;

a second emission layer in the second sub-pixel and configured to emit a second color light;

a first layer that is integrated with the first sub-pixel, the second sub-pixel, and the third sub-pixel;

a first auxiliary layer between the first layer and the first emission layer; and

a first intermediate layer between the first auxiliary layer and the first emission layer,

wherein an absolute value of a highest occupied molecular orbital (HOMO) energy level of the first intermediate layer is larger than an absolute value of a HOMO energy level of the first auxiliary layer and smaller than an absolute value of a HOMO energy level of the first emission layer,

an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level of the first intermediate layer is larger than an absolute value of a LUMO energy level of the first auxiliary layer and smaller than an absolute value of a LUMO energy level of the first emission layer,

the first emission layer includes a first host and a first dopant, and

a full width at half maximum (FWHM) of light emitted from the first dopant is about 35 nm or more.

A method of measuring energy levels of a HOMO and a LUMO and a FWHM of a compound may be as follows, but the method is not limited thereto. HOMO and LUMO energy levels of a compound may be measured by using a cyclic voltammetry device, such as a ZIVE SP2 available from Wonatech and using a differential pulse voltammetry (DPV) program. Each sample solution and an electrolyte solution used herein may be as follows, ferrocene may be used as a standard material, and (Bu)₄NPF₆may be used as an electrolyte. For example, a sample solution of a compound to be measured is a 5×10⁻³M dichloromethane solution, a ferrocene sample solution, a (Bu)₄NPF₆electrolyte solution, and a 0.1 M acetonitrile solution. An E_we-I relationship graph of the compound to be measured and the standard material may be drawn, wherein each tangent line is drawn from points at which current is drastically increased, and voltages of points at which the tangent lines contact an x-axis may be recorded. A HOMO energy level of the compound to be measured may be calculated by setting a HOMO energy level of ferrocene at −4.8 eV.

In one embodiment, the FWHM of the light emitted from the first dopant may be in a range of about 35 nm to about 50 nm.

In one embodiment, the first dopant may include an arylamine compound or a styrylamine compound.

In one embodiment, the first dopant may be a compound represented by Formula 501:

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In Formula 501,

Ar₅₀₁may be a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀heterocyclic group,

L₅₀₁to L₅₀₃may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xd1 to xd3 may each independently be an integer from 0 to 3,

R₅₀₁and R₅₀₂may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and

xd4 may be an integer from 1 to 6.

In one embodiment, the first intermediate layer may include a p-dopant, or may include a single film including a p-dopant.

For example, the p-dopant may include at least one selected from a quinone derivative, a metal oxide, and a cyano group-containing compound.

In one embodiment, the first auxiliary layer may include a hole transport compound.

For example, the hole transport compound may include at least one selected from a compound represented by Formula 201 and a compound represented by Formula 202:

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In Formulae 201 and 202,

L₂₀₁to L₂₀₄may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

L₂₀₅may be selected from *-O-*′, *-S-*I, *-N(Q₂₀₁)-*′, a substituted or unsubstituted C₁-C₂₀alkylene group, a substituted or unsubstituted C₂-C₂₀alkenylene group, a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xa1 to xa4 may each independently be an integer from 0 to 3,

xa5 may be an integer from 1 to 10,

R₂₀₁to R₂₀₄and Q₂₀₁may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group,

at least one substituent of the substituted C₃-C₁₀cycloalkylene group, the substituted C₁-C₁₀heterocycloalkylene group, the substituted C₃-C₁₀cycloalkenylene group, the substituted C₁-C₁₀heterocycloalkenylene group, the substituted C₆-C₆₀arylene group, the substituted C₁-C₆₀heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₂₀alkylene group, the substituted C₂-C₂₀alkenylene group, the substituted C₃-C₁₀cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀aryl group, the substituted C₆-C₆₀aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, and a C₁-C₆₀alkoxy group;

a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, and a C₁-C₆₀alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(C₂₁₁)(C₂₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₁₁to Q₁₃, Q₂₁to Q₂₃, and Q₃₁to Q₃₃may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group.

In one embodiment, the light-emitting device may further include a second intermediate layer between the first layer and the second emission layer.

In one embodiment, the light-emitting device may further include a third intermediate layer between the first electrodes and the first layer.

In one embodiment, the light-emitting device may further include a fourth intermediate layer between the first intermediate layer and the first emission layer.

In one embodiment, an absolute value of a HOMO energy level of the fourth intermediate layer may be larger than an absolute value of a HOMO energy level of the first intermediate layer and smaller than an absolute value of a HOMO energy level of the first emission layer, and

an absolute value of a LUMO energy level of the fourth intermediate layer may be larger than an absolute value of a LUMO energy level of the first intermediate layer and smaller than an absolute value of a LUMO energy level of the first emission layer.

In one embodiment, the light-emitting device may further include at least one selected from an electron injection layer and an electron transport layer between the first emission layer and the second electrode and between the second emission layer and the second electrode.

In one embodiment, at least one selected from the electron injection layer and the electron transport layer may include a compound represented by Formula 1:

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In Formula 1,

L₁₁to L₁₃may each independently be selected from a substituted or unsubstituted C₅-C₆₀carbocyclic group and a substituted or unsubstituted C₁-C₆₀heterocyclic group,

a11 to a13 may each independently be selected from 0, 1, 2, and 3,

R₁₁to R₁₃may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group,

at least one substituent of the substituted C₅-C₆₀carbocyclic group, the substituted C₁-C₆₀heterocyclic group, the substituted C₃-C₁₀cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀aryl group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₁₁to Q₁₃, Q₂₁to Q₂₃, and Q₃₁to Q₃₃may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group.

For example, the compound represented by Formula 1 may be represented by Formula 1-1:

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In Formula 1-1,

R₁₁to R₁₃may each independently be the same as defined in connection with R₁₁to R₁₃as described herein above,

Z₁₁to Z₁₃may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl 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 benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a dibenzosilolyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃),

Q₃₁to Q₃₃may each independently be selected from a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group, and

d4 may be an integer from 0 to 4.

For example, at least one selected from the electron injection layer and the electron transport layer may include tri[3-(3-pyridyl)mesityl]borane (3TPYMB):

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In one embodiment, the light-emitting device may further include at least one selected from a hole injection layer and a hole transport layer, between the first electrodes and the first layer, and

at least one selected from the hole injection layer and the hole transport layer may include a p-dopant, or may include a single film including a p-dopant.

In one embodiment, the light-emitting device may further include a buffer layer between the first emission layer and the second electrode and between the second emission layer and the second electrode.

In one embodiment, the first electrode may be an anode, and

the second electrode may be a cathode.

In one embodiment, the anode may be a reflective anode or a semi-transmissive anode, and

the cathode may be a transmissive cathode.

In one embodiment, the light-emitting device may be a top emission device (e.g., a top emission type device).

In one embodiment, a region in the first layer corresponding to the third sub-pixel may emit third color light, and

a resonance order of one selected from the first color light, the second color light, and the third color light may be different from resonance orders of the other two thereof.

In one embodiment, a region in the first layer corresponding to the third sub-pixel may emit third color light, and

a resonance order of the first color light may be larger than or equal to resonance orders of the second color light and the third color light.

In one embodiment, the first color light may be blue light, and the second color light may be red light or green light, and

a region in the first layer corresponding to the third sub-pixel may emit green light or red light.

For example, the first color light may be blue light, and the second color light may be red light, and

a region in the first layer corresponding to the third sub-pixel may emit green light.

For example, the first color light may be blue light, and the second color light may be green light, and

a region in the first layer corresponding to the third sub-pixel may emit red light.

Another aspect of an embodiment of the present disclosure provides a flat panel display apparatus including: a thin-film transistor including a source electrode, a drain electrode, and an active layer; and the light-emitting device, wherein the first electrode of the light-emitting device is electrically coupled to at least one of the source electrode and the drain electrode of the thin-film transistor.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of embodiments will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic cross-sectional view of a light-emitting device according to an embodiment;

FIG. 2 is a schematic cross-sectional view of a light-emitting device according to an embodiment;

FIG. 3 is a graph showing luminance at 0° and 60° of a light-emitting device according to Example 1;

FIG. 4 is a graph showing luminance at 0° and 60° of a light-emitting device according to Comparative Example 1;

FIG. 5 illustrates electroluminescence spectra of light-emitting devices according to Example 1 and Comparative Example 1;

FIG. 6 illustrates electroluminescence spectra of light-emitting devices according to Example 2 and Comparative Example 2; and

FIG. 7 is a graph showing green light emission color coordinates-efficiency of light-emitting devices of Examples 3 and 4.

DETAILED DESCRIPTION

Embodiments of the present disclosure will now be described more fully with reference to exemplary embodiments. The subject matter of the present disclosure may, however, be embodied in many different forms and should not be construed as being 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 concept of the disclosure to those skilled in the art. Features of embodiments of the disclosure, and how to achieve them, will become apparent by reference to the embodiments that will be described herein below in more detail, together with the accompanying drawings.

Hereinafter, embodiments are described in more detail by referring to the attached drawings, and in the drawings, like reference numerals denote like elements, and a redundant explanation thereof will not be repeated herein.

As used herein, the terms as “first”, “second”, etc., are used only to distinguish one component from another, and such components should not be limited by these terms.

As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It will be further understood that the terms “comprises” and/or “comprising,” as used herein, specify the presence of stated features or components, but do not preclude the presence or addition of one or more other features or components.

It will be understood that when a layer, film, region, or plate is referred to as being “formed on,” another layer, film, region, or plate, it can be directly or indirectly formed on the other layer, film, region, or plate. For example, intervening layers, films, regions, or plates may be present. In addition, sizes of components in the drawings may be exaggerated for convenience of explanation. In other words, because sizes and thicknesses of components in the drawings may be arbitrarily illustrated for convenience of explanation, the following embodiments of the present disclosure are not limited thereto.

FIG. 1 is a schematic cross-sectional view of a light-emitting device 100 according to an embodiment.

Referring to FIG. 1, the light-emitting device 100 according to an embodiment may include: a plurality of first electrodes 110 in a first sub-pixel SP1, a second sub-pixel SP2, and a third sub-pixel SP3; a second electrode 150 facing the plurality of first electrodes 110; a first emission layer 130a in the first sub-pixel SP1 and configured to emit a first color light; a second emission layer 130b in the second sub-pixel SP2 and configured to emit a second color light; a first layer 130c that is integrated with the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3; a first auxiliary layer 130′ between the first layer 130c and the first emission layer 130a; and a first intermediate layer 131 between the first auxiliary layer 130′ and the first emission layer 130a, wherein an absolute value of a highest occupied molecular orbital (HOMO) energy level of the first intermediate layer 131 may be larger than an absolute value of a HOMO energy level of the first auxiliary layer 130′ and smaller than an absolute value of a HOMO energy level of the first emission layer 130a. Further, an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level of the first intermediate layer 131 may be larger than an absolute value of a LUMO energy level of the first auxiliary layer 130′ and smaller than an absolute value of a LUMO energy level of the first emission layer 130a. The first emission layer 130a may include a first host and a first dopant, and a full width at half maximum (FWHM) of light emitted from the first dopant may be about 35 nm or more.

In a structure of a light-emitting device 100 including a common layer such as the first layer 130c, when the first layer 130c emits light with primary resonance, the second emission layer 130b may emit light with primary resonance, and the first emission layer 130a emits light with secondary resonance or more. At this time, resonance of the light becomes strong or increased in the first emission layer 130a, and a luminescence spectrum becomes narrow due to such resonance. Thus, a variation according to an angle increases, and luminance according to a viewing angle in a light-emitting device 100 in which R, G, and B are all driven may become unfavorable.

Therefore, in the light-emitting device 100 according to embodiments of the disclosure, because a first dopant configured to emit light having an FWHM of 35 nm or more is included in the first emission layer 130a, a change in a luminescence spectrum is minimized or reduced even when resonance becomes strong or increased in the first emission layer 130a, thereby preventing or reducing a deterioration in luminance according to an angle.

For example, the FWHM of light emitted from the first dopant may be in a range of about 35 nm to about 50 nm.

A material for the first dopant is not particularly limited as long as the material is configured to emit light that satisfies the FWHM range, and an exemplary, non-limiting structure will be described herein.

In one embodiment, the light-emitting device 100 may further include a second intermediate layer 132 between the first layer 130c and the second emission layer 130b and a third intermediate layer 133 between the first electrode 110 and the first layer 130c.

In some embodiments, the light-emitting device 100 may further include at least one selected from a hole injection layer 121 and a hole transport layer between the first electrode 110 and the first layer 130c. The light-emitting device 100 may further include at least one selected from an electron injection layer and an electron transport layer 142 between the first emission layer 130a and the second electrode 150 and between the second emission layer 130b and the second electrode 150. The light-emitting device 100 may further include a buffer layer 141 between the first emission layer 130a and the second electrode 150 and between the second emission layer 130b and the second electrode 150. The foregoing layers will be described herein below in more detail.

In one embodiment, as described herein above, the first layer 130c is integrated with the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3. For example, the first layer 130c may be a common layer.

For example, the first layer 130c may be between the first electrode 110 and the first emission layer 130a and between the first electrode 110 and the second emission layer 130b.

In an example of a structure of an existing light-emitting device including two or more emission layers and a common layer, holes are injected through the common layer, and thus, one layer is inserted between the lower emission layer (common layer) and the upper emission layer.

In one embodiment, unlike the structure of an existing light-emitting device, two layers, for example, the first auxiliary layer 130′ and the first intermediate layer 131 are included between the first layer 130c and the first emission layer 130a. For example, because the first intermediate layer 131 is further included between the first auxiliary layer 130′ and the first emission layer 130a, the transport of holes injected from the first layer 130c to the first auxiliary layer 130′ may be facilitated, and electrons injected through the electron transport layer 142 to the first emission layer 130a may be prevented from or reduced in crossing over the hole transport region without emitting light in the emission layer.

Furthermore, because an absolute value of a HOMO energy level of the first intermediate layer 131 is larger than an absolute value of a HOMO energy level of the first auxiliary layer 130′ and smaller than an absolute value of a HOMO energy level of the first emission layer 130a, the injection of holes from the first auxiliary layer 130′ to the first emission layer 130a may be facilitated or improved.

In addition, because an absolute value of a LUMO energy level of the first intermediate layer 131 is smaller than an absolute value of a LUMO energy level of the first emission layer 130a, the blocking of electrons may be further facilitated or improved.

In one embodiment, the first emission layer 130a may include a light-emitting material, for example, a host material, an absolute value of a HOMO energy level of the first intermediate layer 131 may be larger than an absolute value of a HOMO energy level of the first auxiliary layer 130′ and smaller than an absolute value of a HOMO energy level of the host material included in the first emission layer 130a, and an absolute value of a LUMO energy level of the first intermediate layer 131 may be larger than an absolute value of a LUMO energy level of the first auxiliary layer 130′ and smaller than an absolute value of a LUMO energy level of the host material included in the first emission layer 130a.

The light-emitting device 100 according to the embodiment will be described herein in more detail.

First Electrode 110

In FIG. 1, a substrate may be additionally under the first electrode 110 or above the second electrode 150. The substrate may be a glass substrate or a plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance.

For example, when the light-emitting device 100 is a top emission device (e.g., a top emission type or a top emission kind of device) configured to emit light in a direction opposite to the substrate, the substrate does not essentially need to be transparent, and may be, for example, opaque, semi-transmissive, or reflective. In some embodiments, metal may be used to form the substrate. When the substrate is formed of metal, the substrate may include at least one selected from carbon, iron, chromium, manganese, nickel, titanium, molybdenum, stainless steel (SUS), Invar alloy, an inconel alloy, and a kovar alloy.

In addition, the light-emitting device 100 may further include a buffer layer, a thin-film transistor, an organic insulation layer, and/or the like between the substrate and the first electrode 110.

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, the material for forming the first electrode 110 may be selected from materials having a high work function to facilitate hole injection.

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 a first electrode 110 may be selected from indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), and any combinations thereof, but embodiments of the present disclosure are not limited thereto. In one or more embodiments, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, a material for forming a first electrode 110 may be selected from magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), and any combinations thereof, but embodiments of the present disclosure are not limited thereto.

The first electrode 110 may have a single-layered structure, or a multi-layered structure including two or more layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO, but the structure of the first electrode 110 is not limited thereto.

For example, when the anode is a semi-transmissive anode, the anode may include at least one transparent conductive layer selected from tin oxide (SnO₂), indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In₂O₃), indium gallium oxide (IGO), and aluminum zinc oxide (AZO), and a semi-transmissive thin film having a thickness of several nm to tens of nm so as to improve luminescent efficiency and including silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), indium (In), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), ytterbium (Yb), and any combination thereof.

For example, when the anode is a reflective anode, the anode may include a reflective film including Ag, Mg, Al, Pt, Pd, Au, Ni, In, Nd, Ir, Cr, Li, Ca, Yb, and/or any combination thereof, and/or a transparent conductive layer above and/or below the reflective film.

The present disclosure is not limited the foregoing. The anode may include various suitable materials, and the structure of the anode may be variously changed. For example, the anode may have a single-layered structure or a multi-layered structure.

A thickness of the anode may be in a range of about 50 nm to about 110 nm. When the thickness of the anode is within this range, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.

The light-emitting device 100 may further include a hole transport region between the first electrode 110 and the first layer 130c, and/or an electron transport region between the first emission layer 130a and the second electrode 150 and between the second emission layer 130b and the second electrode 150.

Hole Transport Region and First Auxiliary Layer 130′

The hole transport region may have i) a single-layered structure including a single layer including a single material, ii) a single-layered structure including a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The hole transport region may include, in addition to a hole injection layer 121, of FIG. 1 at least one layer selected from a hole transport layer, an emission auxiliary layer, and an electron blocking layer.

For example, the hole transport region may have a single-layered structure including a single layer including a plurality of different materials, or a multi-layered structure having 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 for each structure, constituting layers are sequentially stacked from the first electrode 110 in this stated order, but the structure of the hole transport region is not limited thereto.

In one or more embodiments, the first auxiliary layer 130′ may include a hole transport compound included in the hole transport region.

The hole transport region and the first auxiliary layer 130′ may include at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB (NPD), β-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), a compound represented by Formula 201, and a compound represented by Formula 202:

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In Formulae 201 and 202,

L₂₀₅may be selected from *—O—*′, *—S—*I, *—N(Q₂₀₁)-*′, a substituted or unsubstituted C₁-C₂₀alkylene group, a substituted or unsubstituted C₂-C₂₀alkenylene group, a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xa1 to xa4 may each independently be an integer from 0 to 3,

xa5 may be an integer from 1 to 10, and

R₂₀₁to R₂₀₄and Q₂₀₁may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.

In one embodiment, in Formula 202, R₂₀₁and R₂₀₂may optionally be linked via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group, and R₂₀₃and R₂₀₄may optionally be linked via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group.

In one or more embodiments, in Formulae 201 and 202,

L₂₀₁to L₂₀₅may each independently be selected from:

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl 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 naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂), and

Q₃₁to Q₃₃may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In one or more embodiments, xa1 to xa4 may each independently be 0, 1, or 2.

In one or more embodiments, xa5 may be 1, 2, 3, or 4.

In one or more embodiments, R₂₀₁to R₂₀₄and Q₂₀₁may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl 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 naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl 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 naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂), and

Q₃₁to Q₃₃are the same as described herein above.

In one or more embodiments, at least one selected from R₂₀₁to R₂₀₃in Formula 201 may each independently be selected from:

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group; and

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀alkyl group, a phenyl group substituted with —F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,

but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, in Formula 202, i) R₂₀₁and R₂₀₂may be linked via a single bond, and/or ii) R₂₀₃and R₂₀₄may be linked via a single bond.

In one or more embodiments, at least one selected from R₂₀₁to R₂₀₄in Formula 202 may each independently be selected from:

a carbazolyl group; and

a carbazolyl group substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀alkyl group, a phenyl group substituted with —F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,

but embodiments of the present disclosure are not limited thereto.

The compound represented by Formula 201 may be represented by Formula 201A:

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In one embodiment, the compound represented by Formula 201 may be represented by Formula 201A(1), but embodiments of the present disclosure are not limited thereto:

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In one embodiment, the compound represented by Formula 201 may be represented by Formula 201A-1, but embodiments of the present disclosure are not limited thereto:

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In one embodiment, the compound represented by Formula 202 may be represented by Formula 202A:

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In one embodiment, the compound represented by Formula 202 may be represented by Formula 202A-1:

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In Formulae 201A, 201A(1), 201A-1, 202A, and 202A-1,

L₂₀₁to L₂₀₃, xa1 to xa3, xa5, and R₂₀₂to R₂₀₄are the same as described herein above,

R₂₁₁and R₂₁₂may each independently be the same as defined in connection with R₂₀₃, and

R₂₁₃to R₂₁₇may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl 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 naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group.

The hole transport region and the first auxiliary layer 130′ may include at least one compound selected from Compounds HT1 to HT39, but embodiments of the present disclosure are not limited thereto:

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A thickness of the hole transport region may be in a range of about 100 A to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When the hole transport region includes at least one selected from a hole injection layer 121 and a hole transport layer, the thickness of the hole injection layer 121 may be in a range of about 100 Å to about 9,000 Å, and for example, about 100 Å to about 1,000 Å, and the thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, and for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer 121, and the hole transport layer are within these ranges, suitable or 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 the wavelength of light emitted by an emission layer, and the electron blocking layer may block the flow of electrons from an electron transport region. The emission auxiliary layer and the electron blocking layer may include the materials as described herein above.

p-Dopant

At least one selected from the hole injection layer 121 and the hole transport layer may include a p-dopant, or may include a single film including a p-dopant.

In addition, the first intermediate layer 131, the second intermediate layer 132, and the third intermediate layer 133 may each independently include a p-dopant, or may each independently include a single film including a p-dopant.

In one embodiment, the hole transport region may further include a p-dopant having a lowest unoccupied molecular orbital (LUMO) energy level of about −3.5 eV or less.

The p-dopant may include at least one selected from a quinone derivative, a metal oxide, and a cyano group-containing compound, but embodiments of the present disclosure are not limited thereto.

In one embodiment, the p-dopant may include at least one selected from:

a quinone derivative, such as tetracyanoquinodimethane (TCNQ) or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ);

a metal oxide, such as tungsten oxide or molybdenum oxide;

1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (HAT-CN);

a compound represented by Formula 221; and

p-dopant 1,

but embodiments of the present disclosure are not limited thereto:

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In Formula 221,

R₂₂₁to R₂₂₃may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, wherein at least one selected from R₂₂₁to R₂₂₃may have at least one substituent selected from a cyano group, —F, —Cl, —Br, —I, a C₁-C₂₀alkyl group substituted with —F, a C₁-C₂₀alkyl group substituted with —Cl, a C₁-C₂₀alkyl group substituted with —Br, and a C₁-C₂₀alkyl group substituted with —I.

First Emission Layer 130a, Second Emission Layer 130b, and First Layer 130c

As described herein above, the first emission layer 130a may include a first host and a first dopant, and a full width at half maximum (FWHM) of light emitted from the first dopant may be about 35 nm or more. The first dopant may be configured to emit a first color light.

In addition, the second emission layer 130b and the first layer 130c may include a host and a dopant (e.g., may each include a host and a dopant). The dopant may include at least one selected from a phosphorescent dopant and a fluorescent dopant. The dopant may be configured to emit second color light and third color light.

For example, the first color light to the third color light may each independently be selected from blue light, red light, and green light. An amount of the dopant 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, but embodiments of the present disclosure are not limited thereto.

Thicknesses of the first emission layer 130a, the second emission layer 130b, and the first layer 130c may each independently be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within this range, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.

First Host in First Emission Layer 130a, and Host in Second Emission Layer 130b and First Layer 130c

The first host or the host may each independently include a compound represented by Formula 301:

[Ar₃₀₁]_xb11-[(L₃₀₁)_xb1-R₃₀₁]_xb21. Formula 301

In Formula 301,

Ar₃₀₁may be a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀heterocyclic group,

xb11 may be 1, 2, or 3,

L₃₀₁may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xb1 may be an integer from 0 to 5,

R₃₀₁may be selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀alkynyl group, a substituted or unsubstituted C₁-C₆₀alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂), —B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), and —P(═O)(Q₃₀₁)(Q₃₀₂),

xb21 may be an integer from 1 to 5, and

Q₃₀₁to Q₃₀₃may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group, but embodiments of the present disclosure are not limited thereto.

In one embodiment, Ar₃₀₁in Formula 301 may be selected from:

a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, and a dibenzothiophene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₃₁to Q₃₃may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group, but embodiments of the present disclosure are not limited thereto.

When xb11 in Formula 301 is two or more, two or more Ar₃₀₁(s) may be linked via a single bond.

In one or more embodiments, the compound represented by Formula 301 may be represented by Formula 301-1 or 301-2:

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In Formulae 301-1 and 301-2,

ring A₃₀₁to ring A₃₀₄may each independently be selected from a benzene ring, a naphthalene ring, a phenanthrene ring, a fluoranthene ring, a triphenylene ring, a pyrene ring, a chrysene ring, a pyridine ring, a pyrimidine ring, an indene ring, a fluorene ring, a spiro-bifluorene ring, a benzofluorene ring, a dibenzofluorene ring, an indole ring, a carbazole ring, a benzocarbazole ring, a dibenzocarbazole ring, a furan ring, a benzofuran ring, a dibenzofuran ring, a naphthofuran ring, a benzonaphthofuran ring, a dinaphthofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a naphthothiophene ring, a benzonaphthothiophene ring, and a dinaphthothiophene ring,

X₃₀₁may be O, S, or N-[(L₃₀₄)_xb4-R₃₀₄],

R₃₁₁to R₃₁₄may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

xb22 and xb23 may each independently be 0, 1, or 2,

L₃₀₁, xb1, R₃₀₁, and Q₃₁to Q₃₃are the same as described herein above,

L₃₀₂to L₃₀₄may each independently be the same as defined in connection with L₃₀₁,

xb2 to xb4 may each independently be the same as defined in connection with xb1, and

R₃₀₂to R₃₀₄may each independently be the same as defined in connection with R₃₀₁.

For example, L₃₀₁to L₃₀₄in Formulae 301, 301-1, and 301-2 may each independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, and an azacarbazolylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl 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 thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl 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, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₃₁to Q₃₃are the same as described herein above.

In one embodiment, R₃₀₁to R₃₀₄in Formulae 301, 301-1, and 301-2 may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl 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 thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl 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, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl 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 thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl 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, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₃₁to Q₃₃are the same as described herein above.

In one or more embodiments, the first host or the host may include an alkaline earth metal complex. For example, the first host or the host may be selected from a Be complex (for example, Compound H55), a Mg complex, and a Zn complex.

The first host or the host may include at least one selected from 9,10-di(2-naphthyl)anthracene (ADN), 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), 9,10-di(2-naphthyl)-2-t-butyl-anthracene (TBADN), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene (mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), and Compounds H1 to H55, but embodiments of the present disclosure are not limited thereto:

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Phosphorescent Dopant in Second Emission Layer 130b and First Layer 130c

The phosphorescent dopant may include an organometallic complex represented by Formula 401:

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In Formulae 401 and 402,

M may be selected from iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), rhodium (Rh), and thulium (Tm),

L₄₀₁may be selected from ligands represented by Formula 402, and xc1 may be 1, 2, or 3, wherein, when xc1 is two or more, two or more L₄₀₁(s) may be identical to or different from each other,

L₄₀₂may be an organic ligand, and xc2 may be an integer from 0 to 4, wherein, when xc2 is two or more, two or more L₄₀₂(s) may be identical to or different from each other,

X₄₀₁to X₄₀₄may each independently be nitrogen or carbon,

X₄₀₁and X₄₀₃may be linked via a single bond or a double bond, and X₄₀₂and X₄₀₄may be linked via a single bond or a double bond,

A₄₀₁and A₄₀₂may each independently be selected from a C₅-C₆₀carbocyclic group or a C₁-C₆₀heterocyclic group,

X₄₀₅may be a single bond, *—O—*′, *—S—*I, *—C(═O)—*′, *—N(Q₄₁₁)-*′, *—C(Q₄₁₁)(Q₄₁₂)-*′, *—C(Q₄₁₁)=C(Q₄₁₂)-*′, *—C(Q₄₁₁)=*′, or *═C=*′, wherein Q₄₁₁and Q₄₁₂may be hydrogen, deuterium, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group,

X₄₀₆may be a single bond, O, or S,

R₄₀₁and R₄₀₂may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₂₀alkyl group, a substituted or unsubstituted C₁-C₂₀alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂), wherein Q₄₀₁to Q₄₀₃may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a C₆-C₂₀aryl group, and a C₁-C₂₀heteroaryl group,

xc11 and xc12 may each independently be an integer from 0 to 10, and

* and *¹in Formula 402 each indicate a binding site to M in Formula 401.

In one embodiment, A₄₀₁and A₄₀₂in Formula 402 may each independently be selected from a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, an indene group, a pyrrole group, a thiophene group, a furan group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a quinoxaline group, a quinazoline group, a carbazole group, a benzimidazole group, a benzofuran group, a benzothiophene group, an isobenzothiophene group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a dibenzofuran group, and a dibenzothiophene group.

In one or more embodiments, in Formula 402, i) X₄₀₁may be nitrogen, and X₄₀₂may be carbon, or ii) X₄₀₁and X₄₀₂may each be nitrogen at the same time.

In one or more embodiments, R₄₀₁and R₄₀₂in Formula 402 may each independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, and a C₁-C₂₀alkoxy group;

a C₁-C₂₀alkyl group and a C₁-C₂₀alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a phenyl group, a naphthyl group, a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, and a norbornenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group; and

—Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂), and

Q₄₀₁to Q₄₀₃may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, and a naphthyl group, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, when xc1 in Formula 401 is two or more, two A₄₀₁(s) in two or more L₄₀₁(s) may optionally be linked via X₄₀₇, which is a linking group, or two A₄₀₂(s) in two or more L₄₀₁(s) may optionally be linked via X₄₀₈, which is a linking group (see Compounds PD1 to PD4 and PD7). X₄₀₇and X₄₀₈may each independently be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₃)-*′, *—C(Q₄₁₃)(Q₄₁₄)-*′, or *—C(Q₄₁₃)=C(Q₄₁₄)-*′ (wherein Q₄₁₃and Q₄₁₄may each independently be hydrogen, deuterium, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group), but are not limited thereto.

L₄₀₂in Formula 401 may be a monovalent, divalent, or trivalent organic ligand. For example, L₄₀₂may be selected from halogen, diketone (for example, acetylacetonate), carboxylic acid (for example, picolinate), —C(═O), isonitrile, —CN, and a phosphorus-containing material (for example, phosphine or phosphite), but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the phosphorescent dopant may be selected from, for example, Compounds PD1 to PD25, but embodiments of the present disclosure are not limited thereto:

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First Dopant in First Emission Layer 130a and Fluorescent Dopant in Second Emission Layer 130b and First Layer 130c

The first dopant may include an arylamine compound or a styrylamine compound.

The fluorescent dopant may include an arylamine compound or a styrylamine compound.

The first dopant or the fluorescent dopant may each independently include a compound represented by Formula 501:

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In Formula 501,

Ar₅₀₁may be a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀heterocyclic group,

xd1 to xd3 may each independently be an integer from 0 to 3,

xd4 may be an integer from 1 to 6.

In one embodiment, Ar₅₀₁in Formula 501 may be selected from:

a naphthalene group, a heptalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, and an indenophenanthrene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In one or more embodiments, L₅₀₁to L₅₀₃in Formula 501 may each independently be selected from:

In one or more embodiments, R₅₀₁and R₅₀₂in Formula 501 may each independently be selected from:

Q₃₁to Q₃₃may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In one or more embodiments, xd4 in Formula 501 may be 2, but embodiments of the present disclosure are not limited thereto.

For example, the first dopant or the fluorescent dopant may be selected from Compounds FD1 to FD22:

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In one embodiment, the first dopant or the fluorescent dopant may be selected from the following compounds, but embodiments of the present disclosure are not limited thereto:

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Electron Transport Region

The electron transport region may have i) a single-layered structure including a single layer including a single material, ii) a single-layered structure including a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The electron transport region may further include, in addition to the electron transport layer 142 or the buffer layer 141 shown in FIG. 1, at least one layer selected from a hole blocking layer, an electron control layer, and an electron injection layer, but embodiments of the present disclosure are not limited thereto.

For example, the 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 for each structure, constituting layers are sequentially stacked from an emission layer in this stated order. However, embodiments of the structure of the electron transport region are not limited thereto.

The electron transport region may further optionally include, in addition to the electron transport layer 142 shown in FIG. 1, an electron injection layer.

At least one selected from the electron injection layer and the electron transport layer 142 may include a compound represented by Formula 1:

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In Formula 1,

L₁₁to L₁₃may each independently be selected from a substituted or unsubstituted C₅-C₆₀carbocyclic group, and a substituted or unsubstituted C₁-C₆₀heterocyclic group,

a11 to a13 may each independently be 0, 1, 2, and 3,

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₁₁to Q₁₃, Q₂₁to Q₂₃, and Q₃₁to Q₃₃may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group.

In the light-emitting device including the common layer, a driving voltage inevitably increases, as compared with other light-emitting devices. In order to minimize or reduce the increase of the driving voltage, the third color light emitted in the common layer may be emitted with primary resonance. In this case, due to the surface plasmon effect, the luminescent efficiency of the third color light is reduced, as compared with the case where light is emitted with secondary resonance.

The light-emitting device 100 according to the embodiment may improve the luminescent efficiency and/or decrease the driving voltage by including the compound represented by Formula 1 in the electron transport layer 142 included in the electron transport region.

In some embodiments, the compound represented by Formula 1 has low refractive characteristics. When the compound is introduced into the electron transport region, the transmittance of the electron transport region increases, and a light-coupling effect is maximized or increased, thereby increasing luminescent efficiency.

For example, the compound represented by Formula 1 may be represented by Formula 1-1:

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In Formula 1-1,

R₁₁to R₁₃may each independently the same as defined in connection with R₁₁to R₁₃as described herein above,

d4 may be an integer from 0 to 4.

For example, at least one selected from the electron injection layer and the electron transport layer 142 may include tri[3-(3-pyridyl)mesityl]borane (3TPYMB):

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The electron transport region (for example, a buffer layer, a hole blocking layer, an electron control layer, and/or an electron transport layer 142 in the electron transport region) may include a metal-free compound containing at least one π electron-depleted nitrogen-containing ring.

The term “π electron-depleted nitrogen-containing ring,” as used herein, refers to a C₁-C₆₀heterocyclic group having at least one *—N═*′ moiety as a ring-forming moiety.

For example, the “π electron-depleted nitrogen-containing ring” may be i) a 5-membered to 7-membered heteromonocyclic group having at least one *—N═*′ moiety, ii) a heteropolycyclic group in which two or more 5-membered to 7-membered heteromonocyclic groups each having at least one *—N=*′ moiety are condensed with each other (e.g., combined together), or iii) a heteropolycyclic group in which at least one of 5-membered to 7-membered heteromonocyclic groups, each having at least one *—N=*′ moiety, is condensed with (e.g., combined with) at least one C₅-C₆₀carbocyclic group.

Examples of the π electron-depleted nitrogen-containing ring include an imidazole, a pyrazole, a thiazole, an isothiazole, an oxazole, an isoxazole, a pyridine, a pyrazine, a pyrimidine, a pyridazine, an indazole, a purine, a quinoline, an isoquinoline, a benzoquinoline, a phthalazine, a naphthyridine, a quinoxaline, a quinazoline, a cinnoline, a phenanthridine, an acridine, a phenanthroline, a phenazine, a benzimidazole, an isobenzothiazole, a benzoxazole, an isobenzoxazole, a triazole, a tetrazole, an oxadiazole, a triazine, a thiadiazole, an imidazopyridine, an imidazopyrimidine, and an azacarbazole, but are not limited thereto.

For example, the electron transport region may include a compound represented by Formula 601:

[Ar₆₀₁]_xe11-[(L₆₀₁)_xe1-R₆₀₁]_xe21 Formula 601

In Formula 601,

Ar₆₀₁may be a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀heterocyclic group,

xe11 may be 1, 2, or 3,

L₆₀₁may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xe1 may be an integer from 0 to 5,

R₆₀₁may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), and —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁to Q₆₀₃may each independently be a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group, and

xe21 may be an integer from 1 to 5.

In one embodiment, at least one of Ar₆₀₁(s) in the number of xe11 and R₆₀₁(s) in the number of xe21 may include the π electron-depleted nitrogen-containing ring.

In one embodiment, Ar₆₀₁in Formula 601 may be selected from:

a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, and an azacarbazole group; and

Q₃₁to Q₃₃may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

When xe11 in Formula 601 is two or more, two or more Ar₆₀₁(s) may be linked via a single bond.

In one or more embodiments, Ar₆₀₁in Formula 601 may be an anthracene group.

In one or more embodiments, a compound represented by Formula 601 may be represented by Formula 601-1:

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In Formula 601-1,

X₆₁₄may be N or C(R₆₁₄), X₆₁₅may be N or C(R₆₁₅), and X₆₁₆may be N or C(R₆₁₆), wherein at least one selected from X₆₁₄to X₆₁₆may be N,

L₆₁₁to L₆₁₃may each independently be the same as described in connection with L₆₀₁,

xe611 to xe613 may each independently be defined the same as xe1,

R₆₁₁to R₆₁₃may each independently be the same as described in connection with R₆₀₁, and

R₆₁₄to R₆₁₆may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In one embodiment, L₆₀₁and L₆₁₁to L₆₁₃in Formulae 601 and 601-1 may each independently be selected from:

but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.

In one or more embodiments, R₆₀₁and R₆₁₁to R₆₁₃in Formula 601 and 601-1 may each independently be selected from:

—S(═O)₂(Q₆₀₁) and —P(═O)(Q₆₀₁)(Q₆₀₂), and

Q₆₀₁and Q₆₀₂are the same as described herein above.

The electron transport region may include at least one compound selected from Compounds ET1 to ET36, but embodiments of the present disclosure are not limited thereto:

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In one or more embodiments, the electron transport region may include at least one selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq3, BAlq, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), and NTAZ:

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Thicknesses of the buffer layer 141, the hole blocking layer, and the electron control layer may each be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. When the thicknesses of the buffer layer 141, the hole blocking layer, and the electron control layer are within these ranges, the electron transport region may have excellent hole blocking characteristics or electron control characteristics without a substantial increase in driving voltage.

A thickness of the electron transport layer 142 may be in a range of about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When the thickness of the electron transport layer 142 is within the range described herein above, the electron transport layer 142 may have suitable or satisfactory electron transportation characteristics without a substantial increase in driving voltage.

The electron transport region (for example, the electron transport layer 142 in the electron transport region) may further include, in addition to the materials described herein above, a metal-containing material.

The metal-containing material may include at least one selected from alkali metal complex and alkaline earth-metal complex. The alkali metal complex may include a metal ion selected from a Li ion, a Na ion, a K ion, a Rb ion, and a Cs ion, and the alkaline earth-metal complex may include a metal ion selected from a Be ion, a Mg ion, a Ca ion, a Sr ion, and a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may be selected from a hydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, a hydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, a hydroxy phenylthiazole, a hydroxy phenyloxadiazole, a hydroxy phenylthiadiazole, a hydroxy phenylpyridine, a hydroxy phenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene, but embodiments of the present disclosure are not limited thereto.

For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (lithium quinolate, LiQ) or ET-D2:

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The electron transport region may include an electron injection layer that facilitates electron injection from the second electrode 150. The electron injection layer may directly contact (e.g., physically contact) the second electrode 150.

The electron injection layer may have i) a single-layered structure including a single layer including a single material, ii) a single-layered structure including a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combinations thereof.

The alkali metal may be selected from Li, Na, K, Rb, and Cs. In one embodiment, the alkali metal may be Li, Na, or Cs. In one or more embodiments, the alkali metal may be Li or Cs, but embodiments of the present disclosure are not limited thereto.

The alkaline earth-metal may be selected from Mg, Ca, Sr, and Ba.

The rare earth-metal may be selected from Sc, Y, Ce, Tb, Yb, and Gd.

The alkali metal compound, the alkaline earth-metal compound, and the rare earth metal compound may be selected from oxides and halides (for example, fluorides, chlorides, bromides, or iodides) of the alkali metal, the alkaline earth-metal, and the rare earth metal.

The alkali metal compound may be selected from alkali metal oxides, such as Li₂O, Cs₂O, or K₂O, and alkali metal halides, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, or KI. In one embodiment, the alkali metal compound may be selected from LiF, Li₂O, NaF, LiI, NaI, CsI, and KI, but embodiments of the present disclosure are not limited thereto.

The alkaline earth-metal compound may be selected from alkaline earth-metal oxides, such as BaO, SrO, CaO, Ba_xSr_1-xO (0<x<1), or Ba_xCa_1-xO (0<x<1). In one embodiment, the alkaline earth-metal compound may be selected from BaO, SrO, and CaO, but embodiments of the present disclosure are not limited thereto.

The rare earth metal compound may be selected from YbF₃, ScF₃, Sc₂O₃, Y₂O₃, Ce₂O₃, GdF₃, and TbF₃. In one embodiment, the rare earth metal compound may be selected from YbF₃, ScF₃, TbF₃, YbI₃, ScI₃, and TbI₃, but embodiments of the present disclosure are not limited thereto.

The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include an ion of alkali metal, alkaline earth-metal, and rare earth metal as described herein above, and a ligand coordinated with a metal ion of the alkali metal complex, the alkaline earth-metal complex, or the rare earth metal complex may be selected from hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline, hydroxy acridine, hydroxy phenanthridine, hydroxy phenyloxazole, hydroxy phenylthiazole, hydroxy phenyloxadiazole, hydroxy phenylthiadiazole, hydroxy phenylpyridine, hydroxy phenylbenzimidazole, hydroxy phenylbenzothiazole, bipyridine, phenanthroline, and cyclopentadiene, but embodiments of the present disclosure are not limited thereto.

The electron injection layer may consist of (or include) an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combinations thereof, as described herein above. In one or more embodiments, the electron injection layer may further include an organic material. When the electron injection layer further includes an organic material, an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combinations thereof may be homogeneously or non-homogeneously dispersed in a matrix including the organic material.

A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the range described herein above, the electron injection layer may have suitable or satisfactory electron injection characteristics without a substantial increase in driving voltage.

Also, the electron injection layer may further include, in addition to the materials described herein above, a metal-containing material.

Second Electrode 150

The light-emitting device 100 may include a first electrode 110 and a second electrode 150 facing the first electrode 110. The second electrode 150 may be a cathode which is an electron injection electrode, and in this regard, a material for forming the second electrode 150 may be selected from metal, an alloy, an electrically conductive compound, and a combination thereof, which have a relatively low work function.

The second electrode 150 may include at least one selected from lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ITO, and IZO, but embodiments of the present disclosure are not limited thereto. 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 including two or more layers.

For example, the first electrode 110 may be an anode, and the second electrode 150 may be a cathode. Here, the anode may be reflective or semi-transmissive.

Description of FIG. 2

FIG. 2 is a schematic cross-sectional view of a light-emitting device 200 according to another embodiment.

Referring to FIG. 2, the light-emitting device 200 according to another embodiment may include: a plurality of first electrodes 210 in a first sub-pixel SP1, a second sub-pixel SP2, and a third sub-pixel SP3; a second electrode 250 facing the plurality of first electrodes 210; a first emission layer 230a in the first sub-pixel SP1 and configured to emit a first color light; a second emission layer 230b in the second sub-pixel SP2 and configured to emit a second color light; a first layer 230c that is integrated with the first sub-pixel SP1, the second sub-pixel SP2, and the third sub-pixel SP3; a first auxiliary layer 230′ between the first layer 230c and the first emission layer 230a; and a first intermediate layer 231 between the first auxiliary layer 230′ and the first emission layer 230a, wherein an absolute value of a HOMO energy level of the first intermediate layer 231 may be larger than an absolute value of a HOMO energy level of the first auxiliary layer 230′ and smaller than an absolute value of a HOMO energy level of the first emission layer 230a. Further, an absolute value of a LUMO energy level of the first intermediate layer 231 may be larger than an absolute value of a LUMO energy level of the first auxiliary layer 230′ and smaller than an absolute value of a LUMO energy level of the first emission layer 230a, the first emission layer 230a may include a first host and a first dopant, and a FWHM of light emitted from the first dopant may be about 35 nm or more.

Furthermore, in one embodiment, the light-emitting device 200 may further include a second intermediate layer 232 between the first layer 230c and the second emission layer 230b, and may further include a third intermediate layer 233 between the first electrode 210 and the first layer 230c.

In addition, in one embodiment, the light-emitting device 200 may further include at least one selected from a hole injection layer 221 and a hole transport layer between the first electrode 210 and the first layer 230c. The light-emitting device 200 may further include at least one selected from an electron injection layer and an electron transport layer 242 between the first emission layer 230a and the second electrode 250 and between the second emission layer 230b and the second electrode 250, and may further include a buffer layer 241 between the first emission layer 230a and the second electrode 250 and between the second emission layer 230b and the second electrode 250.

The first electrode 210, the second electrode 250, the first emission layer 230a, the second emission layer 230b, the first layer 230c, the first auxiliary layer 230′, the first intermediate layer 231, the second intermediate layer 232, the third intermediate layer 233, the electron transport layer 242, and the buffer layer 241 in FIG. 2 may each independently be the same as described herein above with respect to the corresponding feature of FIG. 1.

In some embodiments, the light-emitting device 200 of FIG. 2 differs from the light-emitting device 100 illustrated in FIG. 1 in terms of structure in that a fourth intermediate layer 234 is further included as an additional intermediate layer.

In some embodiments, the light-emitting device 200 may further include the fourth intermediate layer 234 between the first intermediate layer 231 and the first emission layer 230a. At this time, an absolute value of a HOMO energy level of the fourth intermediate layer 234 may be larger than an absolute value of a HOMO energy level of the first intermediate layer 231 and smaller than an absolute value of a HOMO energy level of the first emission layer 230a, and an absolute value of a LUMO energy level of the fourth intermediate layer 234 may be larger than an absolute value of a LUMO energy level of the first intermediate layer 231 and smaller than an absolute value of a LUMO energy level of the first emission layer 230a.

The fourth intermediate layer 234 may be understood by referring to the description provided with respect to the first intermediate layer 131 to the third intermediate layer 133 of FIG. 1.

In one embodiment, a region in the first layer 230c corresponding to the third sub-pixel SP3 may be configured to emit a third color light, and

a resonance order of one selected from the first color light, the second color light, and the third color light may be different from resonance orders of the other two thereof.

In one embodiment, a region in the first layer 230c corresponding to the third sub-pixel SP3 may emit the third color light, and

a resonance order of the first color light may be larger than or equal to resonance orders of the second color light and the third color light.

For example, i) the resonance order of the first color light is secondary, and the resonance orders of the second color light and the third color light are primary, ii) the resonance order of the first color light is tertiary, and the resonance orders of the second color light and the third color light are secondary, or iii) the resonance order of the first color light is secondary, the resonance order of the second color light is secondary, and the resonance order of the third color light is primary.

In one embodiment, the first color light may be blue light, the second color light may be red light, and the region in the first layer 230c corresponding to the third sub-pixel SP3 may be configured to emit green light.

In one or more embodiments, the first color light may be red light, the second color light may be blue light, and the region in the first layer 230c corresponding to the third sub-pixel SP3 may be configured to emit green light.

In one or more embodiments, the first color light may be green light, the second color light may be red light, and the region in the first layer 230c corresponding to the third sub-pixel SP3 may be configured to emit blue light.

In one or more embodiments, the first color light may be red light, the second color light may be green light, and the region in the first layer 230c corresponding to the third sub-pixel SP3 may be configured to emit blue light.

In one or more embodiments, the first color light may be blue light, the second color light may be green light, and the region in the first layer 230c corresponding to the third sub-pixel SP3 may be configured to emit red light.

In one or more embodiments, the first color light may be green light, the second color light may be blue light, and the region in the first layer 230c corresponding to the third sub-pixel SP3 may be configured to emit red light.

Layers included in the light-emitting device may each be formed by using one or more suitable methods selected from vacuum deposition, spin coating, casting, a LB method, ink-jet printing, laser-printing, and laser-induced thermal imaging.

When layers included in the light-emitting device are each formed by vacuum deposition, the vacuum deposition may be performed at a deposition temperature of about 100° C. to about 500° C., a vacuum degree of about 10⁻⁸torr to about 10⁻³torr, and a deposition speed of about 0.01 Å/sec to about 100 Å/sec by taking into account a composition of a material to be included in a layer to be formed, and the structure of a layer to be formed.

When layers included in the light-emitting device are each formed by spin coating, the spin coating may be, for example, performed at a coating rate of about 2,000 rpm to about 5,000 rpm, and at a temperature of about 80° C. to about 200° C. by taking into account the compound for the layer to be spin-coated, and the structure of the layer to be formed.

The term “C₁-C₆₀alkyl group,” as used herein, refers to a linear or branched aliphatic saturated hydrocarbon monovalent group having 1 to 60 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isoamyl group, and a hexyl group. The term “C₁-C₆₀alkylene group,” as used herein, refers to a divalent group having substantially the same structure as the C₁-C₆₀alkyl group.

The term “C₆-C₆₀aryl group,” as used herein, refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms, and a “C₆-C₆₀arylene group” used herein refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Non-limiting examples of the C₆-C₆₀aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C₆-C₆₀aryl group and the C₆-C₆₀arylene group each include two or more rings, the rings may be fused to each other (e.g., combined together).

The term “C₁-C₆₀heteroaryl group,” as used herein, refers to a monovalent group having a heterocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, in addition to 1 to 60 carbon atoms. The term “C₁-C₆₀heteroarylene group,” as used herein, refers to a divalent group having a heterocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, in addition to 1 to 60 carbon atoms. Non-limiting examples of the C₁-C₆₀heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀heteroaryl group and the C₁-C₆₀heteroarylene group each include two or more rings, the rings may be condensed with each other (e.g., combined together).

The term “monovalent non-aromatic condensed polycyclic group,” as used herein, refers to a monovalent group having two or more rings condensed with each other (e.g., combined together), only carbon atoms (for example, having 8 to 60 carbon atoms) as ring-forming atoms, and no aromaticity in its entire molecular structure (e.g., the entire molecular structure is not aromatic). An example of the monovalent non-aromatic condensed polycyclic group is a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group,” as used herein, refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group,” as used herein, refers to a monovalent group having two or more rings condensed to each other (e.g., combined together), at least one heteroatom selected from N, O, Si, P, and S, other than carbon atoms (for example, having 1 to 60 carbon atoms), as a ring-forming atom, and no aromaticity in its entire molecular structure (e.g., the entire molecular structure is not aromatic). An example of the monovalent non-aromatic condensed heteropolycyclic group is a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group,” as used herein, refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C₅-C₆₀carbocyclic group,” as used herein, refers to a monocyclic or polycyclic group having 5 to 60 carbon atoms in which a ring-forming atom is a carbon atom only. The term “C₅-C₆₀carbocyclic group,” as used herein, refers to an aromatic carbocyclic group or a non-aromatic carbocyclic group. The C₅-C₆₀carbocyclic group may be a ring, such as benzene, a monovalent group, such as a phenyl group, or a divalent group, such as a phenylene group. In one or more embodiments, depending on the number of substituents connected to the C₅-C₆₀carbocyclic group, the C₅-C₆₀carbocyclic group may be a trivalent group or a quadrivalent group.

The term “C₁-C₆₀heterocyclic group,” as used herein, refers to a group having substantially the same structure as the C₅-C₆₀carbocyclic group, except that as a ring-forming atom, at least one heteroatom selected from N, O, Si, P, and S is used in addition to carbon (the number of carbon atoms may be in a range of 1 to 60).

In the present specification, at least one substituent of the substituted C₅-C₆₀carbocyclic group, the substituted C₁-C₆₀heterocyclic group, the substituted C₁-C₂₀alkylene group, the substituted C₂-C₂₀alkenylene group, the substituted C₃-C₁₀cycloalkylene group, the substituted C₁-C₁₀heterocycloalkylene group, the substituted C₃-C₁₀cycloalkenylene group, the substituted C₁-C₁₀heterocycloalkenylene group, the substituted C₆-C₆₀arylene group, the substituted C₁-C₆₀heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀alkyl group, the substituted C₂-C₆₀alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀alkoxy group, the substituted C₃-C₁₀cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀aryl group, the substituted C₆-C₆₀aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₁₁to Q₁₃, Q₂₁to Q₂₃, and Q₃₁to Q₃₃may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group.

The term “biphenyl group,” as used herein, refers to “a phenyl group substituted with a phenyl group.” In other words, the “biphenyl group” is a substituted phenyl group having a C₆-C₆₀aryl group as a substituent.

The term “terphenyl group,” as used herein, refers to “a phenyl group substituted with a biphenyl group.” In other words, the “terphenyl group” is a substituted phenyl group having, as a substituent, a C₆-C₆₀aryl group substituted with a C₆-C₆₀aryl group.

* and *′, as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula.

EXAMPLE

In Examples and Comparative Examples, materials used for the hole injection layer, the hole transport layer, the organic emission layer, the electron transport layer, the electron injection layer, the auxiliary layer, and the intermediate layer correspond to compounds satisfying those described herein with respect to each layer.

Example 1

As an anode, a Corning 15 Ω/cm²(1,200 Å) ITO glass substrate was cut to a size of 50 mm×50 mm×0.7 mm, sonicated with isopropyl alcohol and pure water each for 5 minutes, and then cleaned by exposure to ultraviolet rays and ozone for 30 minutes. Then, the ITO glass substrate was provided to a vacuum deposition apparatus.

HT3 and HAT-CN were co-deposited on the ITO glass substrate to a weight ratio of 99:1 to a thickness of 50 Å and HT3 was deposited thereon to a thickness of 220 Å to form a hole injection layer having a total thickness of 270 Å, and m-MTDATA was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 50 Å.

CBP (host) and Ir(ppy)₃(green dopant) were co-deposited on the hole transport layer to a weight ratio of 94:6 to form a green emission layer having a thickness of 250 Å as a common layer.

Then, HT3 and m-MTDATA were co-deposited on the green emission layer in a blue sub-pixel region to a weight ratio of 99:1 to a thickness of 100 Å and HT3 was additionally deposited thereon to a thickness of 690 Å to form a first auxiliary layer, HAT-CN was deposited on the first auxiliary layer to form a first intermediate layer having a thickness of 50 Å, and CBP (host) and an arylamine compound BD1 (FD14, FWHM: 35 nm) (blue dopant) were co-deposited on the first intermediate layer to a weight ratio of 97:3 to form a blue emission layer having a thickness of 160 Å.

Absolute values of HOMO and LUMO energy levels of the first auxiliary layer, the first intermediate layer, and the blue emission layer were as follows:

First auxiliary layer: HOMO=−5.14 eV, LUMO=−1.82 eV;

First intermediate layer: HOMO=−5.37 eV, LUMO=−2.10 eV; and

Blue emission layer: HOMO=−5.61 eV, LUMO=−2.49 eV.

Then, HAT-CN was deposited on the green emission layer in a red sub-pixel region to form a second intermediate layer having a thickness of 50 Å, and CBP (host) and Ir(btp)₂(acac) (red dopant) were co-deposited on the second intermediate layer to a weight ratio of 97:3 to form a red emission layer having a thickness of 150 Å.

At this time, the red and green emission layers emitted light with primary resonance, and the blue emission layer emitted light with secondary resonance.

BAlq was deposited on the emission layers to a thickness of 50 Å to provide hole blocking layer, and Alq3 and LiQ were co-deposited thereon to a weight ratio of 1:1 to form an electron transport layer having a thickness of 280 Å.

Yb was deposited on the electron transport layer to form an electron injection layer having a thickness of 13 Å, and Ag and Mg were co-deposited thereon to a weight ratio of 9:1 to form a cathode having a thickness of 130 Å, thereby forming a Yb/Ag:Mg electrode. In this manner, a light-emitting device was manufactured.

Comparative Example 1

A light-emitting device was manufactured in substantially the same manner as in Example 1, except that BD2 (5,9-diphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl] phenazaborine (FWHM: 30 nm)) was used as a blue dopant.

Evaluation Example 1

A change in luminance according to an angle (based on luminance (100%) at 0°) in the red, green, and blue emission layers and the entire light-emitting device in the light-emitting device manufactured according to Example 1 was measured, and results thereof are shown in Table 1. A change in luminance according to an angle was equally measured with respect to the light-emitting device manufactured according to Comparative Example 1, and results thereof are shown in Table 2. In addition, the luminance of the blue dopant BD1 of the light-emitting device manufactured according to Example 1 at 0° and 60° was measured, and results thereof are shown in FIG. 3. The luminance of the blue dopant BD2 of the light-emitting device manufactured according to Comparative Example 1 at 0° and 60° was measured, and results thereof are shown in FIG. 4.

TABLE 1

Red
Green
Blue

emission
emission
emission

layer
layer
layer

(primary
(primary
(secondary
Entire light-

Angle
resonance)
resonance)
resonance)
emitting device

0°
100%
100%
100%
100%

10°
99%
98%
97%
98%

20°
94%
91%
87%
90%

30°
81%
80%
72%
77%

40°
70%
67%
39%
52%

50°
45%
57%
29%
39%

60°
41%
51%
24%
33%

TABLE 2

Red
Green
Blue

emission
emission
emission

layer
layer
layer

(primary
(primary
(secondary
Entire light-

Angle
resonance)
resonance)
resonance)
emitting device

0°
100%
100%
100%
100%

10°
99%
98%
97%
98%

20°
94%
91%
88%
91%

30°
81%
80%
71%
76%

40°
70%
67%
39%
53%

50°
45%
57%
13%
24%

60°
41%
51%
10%
19%

Referring to Tables 1 and 2 and FIGS. 3 and 4, it can be seen that in the case of Example 1 in which the blue dopant BD1 configured to emit light having a wide FWHM is applied, a reduction in luminance according to an angle in the blue emission layer is reduced as compared with the case of Comparative Example 1, and a reduction in luminance according to an angle in the entire light-emitting device is reduced, which is advantageous or beneficial to securing a wide viewing angle.

Evaluation Example 2

The electroluminescence spectrums of the light-emitting devices manufactured according to Example 1 and Comparative Example 1 were measured, and results thereof are shown in FIG. 5. From FIG. 5, it can be seen that the light-emitting device manufactured according to Example 1 has excellent luminance, as compared with the light-emitting device manufactured according to Comparative Example 1.

Example 2

CBP (host) and Ir(ppy)₃(green dopant) were co-deposited on the hole transport layer to a weight ratio of 94:6 to form a green emission layer having a thickness of 250 Å as a common layer.

Absolute values of HOMO and LUMO energy levels of the first auxiliary layer, the first intermediate layer, and the blue emission layer are as follows:

First auxiliary layer: HOMO=−5.14 eV, LUMO=−1.82 eV;

First intermediate layer: HOMO=−5.37 eV, LUMO=−2.10 eV; and

Blue emission layer: HOMO=−5.61 eV, LUMO=−2.49 eV.

At this time, the red and green emission layers emitted light with primary resonance, and the blue emission layer emitted light with secondary resonance.

Comparative Example 2

CBP (host) and BD1 (blue dopant) were co-deposited on the hole transport layer to a weight ratio of 97:3 to form a blue emission layer having a thickness of 160 Å as a common layer.

Then, m-MTDATA was additionally deposited on the blue emission layer in a green sub-pixel region to form an auxiliary layer having a thickness of 150 Å, and CBP (host) and Ir(ppy)₃(green dopant) were co-deposited on the auxiliary layer to a weight ratio of 94:6 to form a green emission layer having a thickness of 150 Å.

Then, HAT-CN was deposited on the blue emission layer in a red sub-pixel region to form a second intermediate layer having a thickness of 50 Å, and CBP (host) and Ir(btp)₂(acac) (red dopant) were co-deposited on the second intermediate layer to a weight ratio of 97:3 to form a red emission layer having a thickness of 150 Å.

At this time, the red and blue emission layers emitted light with primary resonance, and the green emission layer emitted light with secondary resonance.

Evaluation Example 3

The luminescence spectrums of the light-emitting devices manufactured according to Example 2 and Comparative Example 2 were measured, and results thereof are shown in FIG. 6.

Referring to FIG. 6, in the case of the light-emitting device of Comparative Example 2 in which a blue common layer is used, a resonance distance is not matched, and light emission occurs in the green light emission region (500 nm to 550 nm) at the time of the blue light emission, unlike the light-emitting device of Example 2. Therefore, a reduction in luminescent efficiency and a change in luminance according to an angle in the light-emitting device increased in Comparative Example 2.

Example 3

CBP (host) and Ir(ppy)₃(green dopant) were co-deposited on the hole transport layer to a weight ratio of 94:6 to form a green emission layer having a thickness of 250 Å as a common layer.

Absolute values of HOMO and LUMO energy levels of the first auxiliary layer, the first intermediate layer, and the blue emission layer are as follows:

First auxiliary layer: HOMO=−5.14 eV, LUMO=−1.82 eV;

First intermediate layer: HOMO=−5.37 eV, LUMO=−2.10 eV; and

Blue emission layer: HOMO=−5.61 eV, LUMO=−2.49 eV.

At this time, the red and green emission layers emitted light with primary resonance, and the blue emission layer emitted light with secondary resonance.

Example 4 (Example in which Low Refractive Electron Transport Layer (ETL) is Applied)

CBP (host) and Ir(ppy)₃(green dopant) were co-deposited on the hole transport layer to a weight ratio of 94:6 to form a green emission layer having a thickness of 250 Å as a common layer.

Absolute values of HOMO and LUMO energy levels of the first auxiliary layer, the first intermediate layer, and the blue emission layer are as follows:

First auxiliary layer: HOMO=−5.14 eV, LUMO=−1.82 eV;

First intermediate layer: HOMO=−5.37 eV, LUMO=−2.10 eV; and

Blue emission layer: HOMO=−5.61 eV, LUMO=−2.49 eV.

At this time, the red and green emission layers emitted light with primary resonance, and the blue emission layer emitted light with secondary resonance.

BAlq was deposited on the emission layers to a thickness of 50 Å to provide hole blocking layer, and 3TPYMB was deposited thereon to form an electron transport layer having a thickness of 280 Å.

embedded image

Evaluation Example 4

FIG. 7 is a graph showing green light emission color coordinates-efficiency of the light-emitting devices manufactured according to Examples 3 and 4.

Referring to FIG. 7, it can be seen that the efficiency of the light-emitting device manufactured according to Example 4 is higher than the efficiency of the light-emitting device manufactured according to Example 3.

According to one or more embodiments, it is possible to implement a light-emitting device in which a driving voltage is reduced and luminance is increased. The scope of the present disclosure, however, is not limited by such an effect.

It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should be considered as available for other similar features or aspects in other embodiments.

Spatially relative terms, such as “beneath,” “below,” “lower,” “under,” “above,” “upper,” and the like, may be used herein for ease of explanation to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or in operation, in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” or “under” other elements or features would then be oriented “above” the other elements or features. Thus, the example terms “below” and “under” can encompass both an orientation of above and below. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly.

As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

As used herein, the terms “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. Further, the use of “may” when describing embodiments of the present disclosure refers to “one or more embodiments of the present disclosure.” As used herein, the terms “use,” “using,” and “used” may be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively. Also, the term “exemplary” is intended to refer to an example or illustration.

Also, any numerical range recited herein is intended to include all sub-ranges of the same numerical precision subsumed within the recited range. For example, a range of “1.0 to 10.0” is intended to include all subranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein, and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited herein.

While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the following claims, and equivalents thereof.

LIGHT-EMITTING DEVICE

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