LIGHT-EMITTING DEVICE

Abstract

A light-emitting device may have excellent or suitable efficiency and/or lifespan. The light-emitting device includes a first electrode; a second electrode facing the first electrode; and an interlayer between the first electrode and the second electrode and including an emission layer, wherein the emission layer includes: a compound represented by Formula 1; and a compound represented by Formula 2:

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0031752, filed on Mar. 11, 2021, in the Korean Intellectual Property Office, the entire content of which is hereby incorporated by reference.

BACKGROUND

1. Field

One or more aspects of embodiments of the present disclosure relate to a light-emitting device.

2. Description of the Related Art

Organic light-emitting devices (OLEDs) are self-emission devices that, compared with devices in the art, may have wide viewing angles, high contrast ratios, short response times, and/or excellent or suitable characteristics in terms of brightness, driving voltage, and/or response speed.

An example OLED may include a first electrode on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode sequentially stacked on the first electrode. Holes provided from the first electrode may move toward the emission layer through the hole transport region, and electrons provided from the second electrode may move toward the emission layer through the electron transport region. Carriers (such as holes and electrons) may recombine in the emission layer to produce excitons. These excitons may transition from an excited state to the ground state to thereby generate light.

SUMMARY

One or more aspects of embodiments of the present disclosure are directed toward a light-emitting device including a novel combination of hosts and a novel host compound.

Additional aspects will be set forth in part in the description that follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.

One or more embodiments of the present disclosure provide:

a light-emitting device including a first electrode,

a second electrode facing the first electrode, and

an interlayer between the first electrode and the second electrode and including an emission layer,

wherein the emission layer may include a compound represented by Formula 1 and a compound represented by Formula 2:

In Formula 1,

R₁, R₂, and Ar′ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_10a, a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_10a, a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_10a, a C₃-C₁₀ cycloalkyl group unsubstituted or substituted with at least one R_10a, a C₁-C₁₀ heterocycloalkyl group unsubstituted or substituted with at least one R_10a, a C₃-C₁₀ cycloalkenyl group unsubstituted or substituted with at least one R_10a, a C₁-C₁₀ heterocycloalkenyl group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_10a, a C₈-C₆₀ monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R_10a, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and —P(═S)(Q₁)(Q₂),

L₁ may be selected from a single bond, a C₆-C₆₀ arylene group unsubstituted or substituted with at least one R_10a and a C₁-C₆₀ heteroarylene group unsubstituted or substituted with at least one R_10a,

R₁, R₂, Ar′, and L₁ may each not be or include an imidazole moiety,

two adjacent R₁ and R₂ substituents may optionally be bound to each other to form a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a,

m may be an integer from 1 to 3, and

1a1 and 1a2 may each independently be an integer from 1 to 4.

In Formula 2,

Ar₁ to Ar₆ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_10a, a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_10a, a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_10a, a C₃-C₁₀ cycloalkyl group unsubstituted or substituted with at least one R_10a, a C₁-C₁₀ heterocycloalkyl group unsubstituted or substituted with at least one R_10a, a C₃-C₁₀ cycloalkenyl group unsubstituted or substituted with at least one R_10a, a C₁-C₁₀ heterocycloalkenyl group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_10a, a C₈-C₆₀ monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R_10a, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and —P(═S)(Q₁)(Q₂),

two adjacent Ar₁ to Ar₆ substituents may optionally be bound to each other to form a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a,

L₂ and L₃ may each independently be selected from a single bond, a C₆-C₆₀ arylene group unsubstituted or substituted with at least one R_10a and a C₁-C₆₀ heteroarylene group unsubstituted or substituted with at least one R_10a,

n1 and n2 may each independently be an integer from 1 to 3,

2a2 may be an integer from 1 to 4,

2a3 may be an integer from 1 to 3, and

R_10a may be:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group,

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, a C₂-C₆₀ heteroaryl alkyl group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or any combination thereof,

a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, or a C₂-C₆₀ heteroaryl alkyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, a C₂-C₆₀ heteroaryl alkyl group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or any combination thereof, or

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

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, or any combination thereof, a C₇-C₆₀ aryl alkyl group, or a C₂-C₆₀ heteroaryl alkyl group.

One or more embodiments of the present disclosure provide an electronic apparatus including the light-emitting device.

According to one or more embodiments, the compound may be represented by Formula 2.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

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

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

FIG. 3 is a schematic cross-sectional view of another light-emitting apparatus according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in more detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout, and duplicative descriptions thereof may not be provided. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the drawings, to explain aspects of the present description. As utilized herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expression “at least one of a, b or c” indicates only a, only b, only c, both (e.g., simultaneously) a and b, both a and c, both b and c, all of a, b, and c, or variations thereof. Expressions such as “at least one of,” “one of,” and “selected from,” 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, singular forms such as “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 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. It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof.

Recently, as display apparatuses become larger, there is an increasing demand for flat display devices that occupy less space. As one of these flat display devices, the technology of organic light-emitting devices is rapidly developing.

An organic light-emitting device is a device that emits light when electrons and holes are respectively injected from an electron injection electrode (cathode) and a hole injection electrode (anode) into an emission layer therebetween, where they combine and extinguish to thereby emit light.

An organic light-emitting device may be formed on a flexible transparent substrate (such as, for example, a plastic substrate). Further, an organic light-emitting device may be driven at a low voltage (less than 10 volts (V)) and/or may have relatively low power consumption and/or rich color.

An organic light-emitting device may include a first electrode formed on a substrate as an anode, a second electrode spaced apart from and facing the first electrode, and an emission layer between the first electrode and the second electrode. To improve luminescence efficiency, the emission layer may in some embodiments further include a hole injection layer, a hole transport layer, an emitting material layer (e.g., as the emission layer), an electron transport layer, and an electron injection layer, or any combination thereof, which may be sequentially stacked on the first electrode (e.g., between the first electrode and the second electrode).

Holes may be transferred from the anode (the first electrode) to the emission layer through the hole injection layer and the hole transport layer, and electrons may be transferred from the cathode (the second electrode) to the emission layer through the electron injection layer and the electron transport layer.

The holes and electrons transferred to the emission layer may combine to form excitons, and the excitons may be excited to an unstable energy state (e.g., an excited state) and return to a stable energy state (e.g., the ground state), thereby emitting light.

An external quantum efficiency (next) of a light-emitting material utilized in the emission layer may be obtained by the following equation:

η_ext=η_int×Γ×θ×η_out-coupling

(η_int: internal quantum efficiency, Γ: charge balance factor, Φ: radiative quantum efficiency, η_out-coupling: out-coupling efficiency).

The term “charge balance factor” (Γ) refers to a balance between holes and electrons used in the formation of excitons. In general, Γ may have a value of 1 in the case of 100 percent (%) of 1:1 matching (e.g., all holes and electrons are matched and utilized to form excitons). The term “radiative quantum efficiency” (Φ) is a value quantifying the involvement of substantial light-emitting materials in luminescence efficiency. Φ may depend on a fluorescent quantum efficiency of dopants in a host-dopant system.

The term “internal quantum efficiency” (η_int) refers to a rate of conversion of generated excitons to light. η_int of a fluorescent material may have a maximum value of 0.25. When excitons are formed by combining holes and electrons, singlet excitons and triplet excitons may be generated in a ratio of 1:3 according to arrangement of spins (e.g., statistical formation of electron spin pairs). However, in fluorescent materials, only singlet excitons may participate in light emission, and the remaining 75% of triplet excitons may not participate in light emission.

The term “out-coupling efficiency” (η_out-coupling) refers to a rate at which emitted light is extracted to the outside with respect to the whole or total emitted light. In general, when a thin film is formed by thermally depositing isotropic molecules, individual light-emitting molecules may not have a particular orientation and may be in a random state. In such a random orientation state, the out-coupling efficiency may be 0.2.

Thus, the maximum luminescence efficiency of an organic light-emitting device utilizing a fluorescent material may be about 5% or less. To overcome this low efficiency problem of fluorescent materials, phosphorescent materials having a light-emitting mechanism that converts both singlet excitons and triplet excitons into light are being developed. Phosphorescent materials having high luminescence efficiency have been developed in the case of red and green emitted light. But in the case of blue, phosphorescent materials satisfying the required luminescence efficiency and reliability have not been suitably developed. Therefore, development of materials capable of increased luminescence efficiency by reliably improving quantum efficiency in a fluorescent material is desired.

According to an embodiment, a light-emitting device may include:

a first electrode;

a second electrode facing the first electrode; and

an interlayer between the first electrode and the second electrode and including an emission layer,

wherein the emission layer may include:

a compound represented by Formula 1; and

a compound represented by Formula 2:

wherein, in Formula 1,

R₁, R₂, and Ar′ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_10a, a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_10a, a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_10a, a C₃-C₁₀ cycloalkyl group unsubstituted or substituted with at least one R_10a, a C₁-C₁₀ heterocycloalkyl group unsubstituted or substituted with at least one R_10a, a C₃-C₁₀ cycloalkenyl group unsubstituted or substituted with at least one R_10a, a C₁-C₁₀ heterocycloalkenyl group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_10a, a C₈-C₆₀ monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R_10a, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and —P(═S)(Q₁)(Q₂),

L₁ may be selected from a single bond, a C₆-C₆₀ arylene group unsubstituted or substituted with at least one R_10a and a C₁-C₆₀ heteroarylene group unsubstituted or substituted with at least one R_10a,

R₁, R₂, Ar′, and L₁ may not include an imidazole moiety,

two adjacent R₁ and R₂ substituents may optionally be bound to each other to form a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a,

m may be an integer from 1 to 3, and

1a1 and 1a2 may each independently be an integer from 1 to 4:

wherein, in Formula 2,

Ar₁ to Ar₆ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_10a, a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_10a, a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_10a, a C₃-C₁₀ cycloalkyl group unsubstituted or substituted with at least one R_10a, a C₁-C₁₀ heterocycloalkyl group unsubstituted or substituted with at least one R_10a, a C₃-C₁₀ cycloalkenyl group unsubstituted or substituted with at least one R_10a, a C₁-C₁₀ heterocycloalkenyl group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_10a, a C₈-C₆₀ monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R_10a, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and —P(═S)(Q₁)(Q₂),

two adjacent substituents in Ar₁ to Ar₆ may optionally be bound to each other to form a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a,

L₂ and L₃ may each independently be selected from a single bond, a C₆-C₆₀ arylene group unsubstituted or substituted with at least one R_10a and a C₁-C₆₀ heteroarylene group unsubstituted or substituted with at least one R_10a,

n1 and n2 may each independently be an integer from 1 to 3,

2a2 may be an integer from 1 to 4,

2a3 may be an integer from 1 to 3, and

R_10a may be:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, a C₂-C₆₀ heteroaryl alkyl group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or any combination thereof;

a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, or a C₂-C₆₀ heteroaryl alkyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, a C₂-C₆₀ heteroaryl alkyl group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or any combination thereof; or

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

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, or any combination thereof; a C₇-C₆₀ aryl alkyl group; or a C₂-C₆₀ heteroaryl alkyl group.

In Formula 1, when m is 2 or greater, at least two L₁(s) may be identical to or different from each other. When 1a1 is 2 or greater, at least two R₁(s) may be identical to or different from each other. When 1a2 is 2 or greater, at least two R₂(s) may be identical to or different from each other.

In Formula 2, when n1 is 2 or greater, at least two L₂(s) may be identical to or different from each other. When n2 is 2 or greater, at least two L₃(s) may be identical to or different from each other. When 2a2 is 2 or greater, at least two Ar₂(s) may be identical to or different from each other. When 2a3 is 2 or greater, at least two Ar₃(s) may be identical to or different from each other.

In some embodiments, the first electrode may be an anode, the second electrode may be a cathode, and the interlayer may further include a hole transport region between the first electrode and the emission layer, which may include a hole injection layer, a hole transport layer, an electron blocking layer, or any combination thereof.

In some embodiments, the first electrode may be an anode, the second electrode may be a cathode, and the interlayer may further include an electron transport region between the second electrode and the emission layer, which may include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

In some embodiments, the emission layer may include a first host having hole transportability and a second host having electron transportability.

For example, the first host may be the compound represented by Formula 1, and the second host may be the compound represented by Formula 2.

The compound represented by Formula 1 may be a compound having hole transportability by including a carbazole group as a core. The compound represented by Formula 2 may be a compound having electron transportability by including an imidazole group linked to a carbazole group as a core.

Due to the first host compound represented by Formula 1 having hole transportability and the second host compound represented by Formula 2 having electron transportability, charge balance in the emission layer of the light-emitting device according to one or more embodiments may be improved or optimized.

By utilizing the first host compound represented by Formula 1 having hole transportability and the second host compound represented by Formula 2 having electron transportability in the emission layer of the light-emitting device according to one or more embodiments, efficiency and/or lifespan may both (e.g., simultaneously) be achieved.

In some embodiments, a weight ratio of the first host to the second host may be in a range of about 1:9 to about 9:1. In some embodiments, a weight ratio of the first host to the second host may be in a range of about 3:7 to about 7:3. In some embodiments, a weight ratio of the first host to the second host may be in a range of about 3:7 to about 5:5. When the weight ratio of the first host to the second host is within any of these ranges, charge balance in the emission layer may be improved or optimized.

In some embodiments, L₁ in Formula 1 may be a C₆-C₆₀ arylene group unsubstituted or substituted with at least one R_10a, and R₁ and R₂ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, or a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_10a.

For example, L₁ in Formula 1 may be a phenylene group unsubstituted or substituted with at least one R_10a, and R₁ and R₂ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, or a carbazole group unsubstituted or substituted with at least one R_10a.

In some embodiments, L₂ and L₃ in Formula 2 may each independently be a single bond or a phenylene group unsubstituted or substituted with at least one R_10a, and Ar₅ and Ar₆ may be bound to each other to form a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a. For example, Ar₅ and Ar₆ may be bound to each other to form a phenyl group unsubstituted or substituted with at least one R_10a.

In some embodiments, Ar₂ and Ar₃ in Formula 2 may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group, and Ar₁ and Ar₄ may each independently be a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_10a or a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_10a.

According to one or more embodiments, a compound represented by Formula 2 may be provided as described above.

In an embodiment, the compound represented by Formula 2 may be represented by Formula 3:

wherein, in Formula 3,

Ar₁ to Ar₄, L₂, L₃, n1, n2, 2a2, and 2a3 may each independently be the same as described in connection with Formula 2, Ar₇ may be the same as described in connection with Ar in Formula 2, and 2a7 may be an integer from 1 to 4.

When 2a7 is an integer of 2 or greater, at least two Ar₇(s) may be identical to or different from each other.

In some embodiments, Ar′ in Formula 1 and Ar₁ to Ar₆ in Formula 2 may each independently be or include a cyano group, moieties 1 to 24, or a combination thereof:

wherein, the substitution position of each of moieties 1 to 24 may be any suitable hydrogen position (e.g., any position at which a hydrogen may be replaced by a linking position or bond). For example, moieties 1 to 24 may be bound to a structure of Formula 1 or Formula 2 via a chemical bond at any suitable hydrogen position of moieties 1 to 24.

The expression that Ar′ and Ar₁ to Ar₆ may each independently include moieties 1 to 24 or a combination thereof indicates that moieties 1 to 24 may be bound to a structure of Formula 1 or Formula 2 at any suitable hydrogen position of moieties 1 to 24 via a chemical bond, and any of the remaining hydrogen positions of moieties 1 to 24 that are not bound via a chemical bond may be substituted with an R_10a.

For example, moiety 1 has 20 hydrogen positions (e.g., ═CH— units), and one of the 20 hydrogen positions may be bound to L₁ in Formula 1 (when L₁ is a single bond, moiety 1 may be bound (for example, directly bound) to N in a carbazole group). The remaining hydrogen positions that are not bound to Formula in moiety 1 may be substituted with at least one R_10a.

For example, moiety 11 has 6 hydrogen positions (e.g., five ═CH— units and one —NH— unit), and one of the 6 hydrogen positions may be bound to N in a carbazole group (for example, when Ar₁ includes the moiety), to a benzene moiety in a carbazole group (for example, when Ar₂ or Ar₃ includes the moiety), to L₃ (for example, when Ar₄ includes the moiety), to ═CH— in an imidazole group (for example, when Ar₄, Ar₅, or Ar₆ includes the moiety) in Formula 2. The remaining hydrogen positions that are not bound to Formula 2 in moiety 11 may be substituted with at least one R_10a.

Basically, Formula 1 may be a hole transporting compound, and Formula 2 may be an electron transporting compound. A cyano group or moieties 1 to 24 may have (e.g., may facilitate) hole transportability or electron transportability.

Because one or more of the substituents Ar′ and Ar₁ to Ar₆ include a cyano group, moieties 1 to 24, or a combination thereof (for example, one or more of moieties 1 to 24, each independently unsubstituted or substituted with a cyano group), the light-emitting device according to one or more embodiments may have improved or optimized charge balance in the emission layer. Accordingly, efficiency and lifespan, which may be difficult to be compatible with each other, may both (e.g., simultaneously) be satisfied.

In some embodiments, a hydrogen position of moieties 1 to 24 may be bound to the core of Formula 1 or Formula 2 via substituents Ar′ and Ar₁ to Ar₆.

The expression ‘includ[ing] moieties 1 to 24 or a combination thereof’ indicates that Ar′ in Formula 1 and Ar₁ to Ar₆ in Formula 2 may collectively bind more than one of moieties 1 to 24, for example, moieties 2 and 6, binding of at least two moieties 6, or moieties 2 and 5.

For example, Ar′ in Formula 1 and Ar₁ to Ar₆ in Formula 2 may collectively bind a cyano group and moiety 5, or a cyano group and moiety 6.

In some embodiments, the compound represented by Formula 1 may be one of the following compounds:

In some embodiments, the compound represented by Formula 2 may be one of the following compounds:

In an embodiment, the emission layer may include a fluorescent dopant. For example, the fluorescent dopant may be a thermally activated delayed fluorescence (TADF) dopant.

In an embodiment, the emission layer may include a phosphorescent dopant. For example, the phosphorescent dopant may be an organometallic compound.

The fluorescent dopant and the phosphorescent dopant may each independently be the same as described herein.

An electronic apparatus may include: a thin-film transistor and the organic light-emitting device, wherein the thin-film transistor may include a source electrode, a drain electrode, an activation layer (e.g., an active layer), and a gate electrode, and the first electrode of the organic light-emitting device may be electrically connected to one of the source electrode or the drain electrode of the thin-film transistor.

The term “interlayer” as utilized herein refers to a single layer and/or a plurality of layers between the first electrode and the second electrode in an organic light-emitting device. A material included in the “interlayer” is not limited to being an organic material. For example, the “interlayer” may include an inorganic material.

Description of FIG. 1

FIG. 1 is a schematic view of a light-emitting device 10 according to an embodiment. The light-emitting device 10 may include a first electrode 110, an interlayer 130, and a second electrode 150.

Hereinafter, the structure of the light-emitting device 10 according to an embodiment and a method of manufacturing the light-emitting device 10 according to an embodiment will be described in connection with FIG. 1.

First Electrode 110

In FIG. 1, a substrate may be additionally located under the first electrode 110 or above the second electrode 150. The substrate may be a glass substrate and/or a plastic substrate. The substrate may be a flexible substrate including plastic having excellent or suitable heat resistance and/or durability, for example, polyimide, polyethylene terephthalate (PET), polycarbonate, polyethylene naphthalate, polyarylate (PAR), polyetherimide, or any combination thereof.

The first electrode 110 may be formed by depositing or sputtering, on the substrate, a material for forming the first electrode 110. When the first electrode 110 is an anode, a high work function material that may easily inject holes may be utilized as a material for a first electrode.

The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, a material for forming the first electrode 110 may be indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), or any combination thereof. In some embodiments, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or any combination thereof may be utilized as a material for forming the first electrode 110.

The first electrode 110 may have a single-layered structure including (e.g., consisting of) a single layer or a multi-layered structure including two or more layers. In some embodiments, the first electrode 110 may have a triple-layered structure of ITO/Ag/ITO.

Interlayer 130

The interlayer 130 may be on the first electrode 110. The interlayer 130 may include an emission layer.

The interlayer 130 may further include a hole transport region between the first electrode 110 and the emission layer, and/or an electron transport region between the emission layer and the second electrode 150.

The interlayer 130 may further include metal-containing compounds (such as organometallic compounds), inorganic materials (such as quantum dots), and/or the like, in addition to various suitable organic materials.

The interlayer 130 may include: i) at least two emitting units sequentially stacked between the first electrode 110 and the second electrode 150; and ii) a charge generation layer located between the at least two emitting units. When the interlayer 130 includes the at least two emitting units and a charge generation layer, the light-emitting device 10 may be a tandem light-emitting device.

Hole Transport Region in Interlayer 130

The hole transport region may have i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) 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 a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or a combination thereof.

For example, the hole transport region may have a multi-layered structure, e.g., 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 layers of each structure are sequentially stacked on the first electrode 110 in each stated order, but embodiments are not limited thereto.

The hole transport region may include the compound represented by Formula 201, the compound represented by Formula 202, or any combination thereof:

wherein, in Formulae 201 and 202,

L₂₀₁ to L₂₀₄ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a,

L₂₀₅ may be *—O—*′, *—S—*′, *—N(Q₂₀₁)—*′, a C₁-C₂₀ alkylene group unsubstituted or substituted with at least one R_10a, a C₂-C₂₀ alkenylene group unsubstituted or substituted with at least one R_10a, a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a, or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a,

xa1 to xa4 may each independently be an integer from 0 to 5,

xa5 may be an integer from 1 to 10,

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a,

R₂₀₁ and R₂₀₂ may optionally be bound to each other via a single bond, a C₁-C₅ alkylene group unsubstituted or substituted with at least one R_10a, or a C₂-C₅ alkenylene group unsubstituted or substituted with at least one R_10a to form a C₈-C₆₀ polycyclic group (e.g., a carbazole group and/or the like) unsubstituted or substituted with at least one R_10a (e.g., Compound HT16 described herein),

R₂₀₃ and R₂₀₄ may optionally be bound to each other via a single bond, a C₁-C₅ alkylene group unsubstituted or substituted with at least one R_10a, or a C₂-C₅ alkenylene group unsubstituted or substituted with at least one R_10a to form a C₈-C₆₀ polycyclic group unsubstituted or substituted with at least one R_10a, and

na1 may be an integer from 1 to 4.

In some embodiments, Formulae 201 and 202 may each include at least one of the groups represented by Formulae CY201 to CY217 (e.g., as one of groups R₂₀₁ to R₂₀₄):

wherein, in Formulae CY201 to CY217, R_10b and R_10c may each be understood by referring to the descriptions of R_10a, ring CY₂₀₁ to ring CY₂₀₄ may each independently be a C₃-C₂₀ carbocyclic group or a C₁-C₂₀ heterocyclic group, and at least one hydrogen in Formulae CY201 to CY217 may be unsubstituted or substituted with R_10a.

In some embodiments, in Formulae CY201 to CY217, ring CY₂₀₁ to ring CY₂₀₄ may each independently be a benzene group, a naphthalene group, a phenanthrene group, or an anthracene group.

In one or more embodiments, Formulae 201 and 202 may each include at least one of groups represented by Formulae CY201 to CY203.

In one or more embodiments, Formula 201 may include at least one of groups represented by Formulae CY201 to CY203 and at least one of groups represented by Formulae CY204 to CY217.

In one or more embodiments, in Formula 201, xa1 may be 1, R₂₀₁ may be a group represented by any one of Formulae CY201 to CY203, xa2 may be 0, and R₂₀₂ may be a group represented by Formulae CY204 to CY207.

In one or more embodiments, Formulae 201 and 202 may each not include groups represented by Formulae CY201 to CY203.

In one or more embodiments, Formulae 201 and 202 may each not include groups represented by Formulae CY201 to CY203, and include at least one of groups represented by Formulae CY204 to CY217.

In one or more embodiments, Formulae 201 and 202 may each not include groups represented by Formulae CY201 to CY217.

In some embodiments, the hole transport region may include one of Compounds HT1 to HT46 and 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/dodecylbenzene sulfonic acid (PANI/DBSA), poly(3,4-ethylene dioxythiophene)/poly(4-styrene sulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrene sulfonate (PANI/PSS), or any combination thereof:

The thickness of the hole transport region may be in a range of about 50 Angstroms (Å) to about 10,000 Å, for example, about 100 Å to about 4,000 Å. When the hole transport region includes a hole injection layer, a hole transport layer, or combination thereof, the thickness of the hole injection layer may be in a range of about 100 Å to about 9,000 Å, 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, for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within any of these ranges, excellent or suitable hole transport characteristics may be obtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase the light emission efficiency of a device by compensating for an optical resonance distance of the wavelength of light emitted by an emission layer. The electron blocking layer may prevent or reduce leakage of electrons to a hole transport region from the emission layer. Materials that may be included in the hole transport region may also be included in the emission auxiliary layer and/or the electron blocking layer.

p-Dopant

The hole transport region may include a charge generating material as well as (e.g., in addition to) the aforementioned materials to improve conductive properties of the hole transport region. The charge generating material may be substantially homogeneously or non-homogeneously dispersed (for example, as a single layer consisting of charge generating material) in the hole transport region.

The charge generating material may include, for example, a p-dopant.

In some embodiments, a lowest unoccupied molecular orbital (LUMO) energy level of the p-dopant may be −3.5 eV or less.

In some embodiments, the p-dopant may include a quinone derivative, a compound containing a cyano group, a compound containing an element EL1 and an element EL2, or any combination thereof.

Examples of the quinone derivative may include TCNQ, F4-TCNQ, and/or the like.

Examples of the compound containing a cyano group include HAT-CN, a compound represented by Formula 221, and/or the like:

wherein, in Formula 221,

R₂₂₁ to R₂₂₃ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a, and

at least one of R₂₂₁ to R₂₂₃ may each independently be: a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, or a C₁-C₂₀ alkyl group substituted with a cyano group, —F, —Cl, —Br, —I, or any combination thereof.

In the compound containing the element EL1 and the element EL2, the element EL1 may be a metal, a metalloid, or a combination thereof, and the element EL2 may be non-metal, a metalloid, or a combination thereof.

Examples of the metal may include: an alkali metal (e.g., lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and/or the like); an alkaline earth metal (e.g., beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and/or the like); a transition metal (e.g., titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), technetium (Tc), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), and/or the like); post-transition metal (e.g., zinc (Zn), indium (In), tin (Sn), and/or the like); a lanthanide metal (e.g., lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and/or the like); and/or the like.

Examples of the metalloid may include silicon (Si), antimony (Sb), tellurium (Te), and/or the like.

Examples of the non-metal may include oxygen (O), halogen (e.g., F, Cl, Br, I, and/or the like), and/or the like.

For example, the compound containing the element EL1 and the element EL2 may include a metal oxide, a metal halide (e.g., metal fluoride, metal chloride, metal bromide, metal iodide, and/or the like), a metalloid halide (e.g., a metalloid fluoride, a metalloid chloride, a metalloid bromide, a metalloid iodide, and/or the like), a metal telluride, or any combination thereof.

Examples of the metal oxide may include a tungsten oxide (e.g., WO, W₂O₃, WO₂, WO₃, W₂O₅, and/or the like), a vanadium oxide (e.g., VO, V₂O₃, VO₂, V₂O₅, and/or the like), a molybdenum oxide (MoO, Mo₂O₃, MoO₂, MoO₃, Mo₂O₅, and/or the like), a rhenium oxide (e.g., ReO₃ and/or the like), and/or the like.

Examples of the metal halide may include an alkali metal halide, an alkaline earth metal halide, a transition metal halide, a post-transition metal halide, a lanthanide metal halide, and/or the like.

Examples of the alkali metal halide may include LiF, NaF, KF, RbF, CsF, LiCl, NaCl, KCl, RbCl, CsCl, LiBr, NaBr, KBr, RbBr, CsBr, LiI, NaI, KI, RbI, CsI, and/or the like.

Examples of the alkaline earth metal halide may include BeF₂, MgF₂, CaF₂, SrF₂, BaF₂, BeCl₂, MgCl₂, CaCl₂, SrCl₂, BaCl₂, BeBr₂, MgBr₂, CaBr₂, SrBr₂, BaBr₂, BeI₂, MgI₂, CaI₂, SrI₂, BaI₂, and/or the like.

Examples of the transition metal halide may include a titanium halide (e.g., TiF₄, TiCl₄, TiBr₄, TiI₄, and/or the like), a zirconium halide (e.g., ZrF₄, ZrCl₄, ZrBr₄, ZrI₄, and/or the like), a hafnium halide (e.g., HfF₄, HfCl₄, HfBr₄, HfI₄, and/or the like), a vanadium halide (e.g., VF₃, VCl₃, VBr₃, VI₃, and/or the like), a niobium halide (e.g., NbF₃, NbCl₃, NbBr₃, NbI₃, and/or the like), a tantalum halide (e.g., TaF₃, TaCl₃, TaBr₃, TaI₃, and/or the like), a chromium halide (e.g., CrF₃, CrCl₃, CrBr₃, CrI₃, and/or the like), a molybdenum halide (e.g., MoF₃, MoCl₃, MoBr₃, MoI₃, and/or the like), a tungsten halide (e.g., WF₃, WCl₃, WBr₃, WI₃, and/or the like), a manganese halide (e.g., MnF₂, MnCl₂, MnBr₂, MnI₂, and/or the like), a technetium halide (e.g., TcF₂, TcCl₂, TcBr₂, TcI₂, and/or the like), a rhenium halide (e.g., ReF₂, ReCl₂, ReBr₂, ReI₂, and/or the like), an iron halide (e.g., FeF₂, FeCl₂, FeBr₂, FeI₂, and/or the like), a ruthenium halide (e.g., RuF₂, RuCl₂, RuBr₂, RuI₂, and/or the like), an osmium halide (e.g., OsF₂, OsCl₂, OsBr₂, OsI₂, and/or the like), a cobalt halide (e.g., CoF₂, CoCl₂, CoBr₂, COI₂, and/or the like), a rhodium halide (e.g., RhF₂, RhCl₂, RhBr₂, RhI₂, and/or the like), an iridium halide (e.g., IrF₂, IrCl₂, IrBr₂, IrI₂, and/or the like), a nickel halide (e.g., NiF₂, NiCl₂, NiBr₂, NiI₂, and/or the like), a palladium halide (e.g., PdF₂, PdCl₂, PdBr₂, PdI₂, and/or the like), a platinum halide (e.g., PtF₂, PtCl₂, PtBr₂, PtI₂, and/or the like), a copper halide (e.g., CuF, CuCl, CuBr, CuI, and/or the like), a silver halide (e.g., AgF, AgCl, AgBr, AgI, and/or the like), a gold halide (e.g., AuF, AuCl, AuBr, AuI, and/or the like), and/or the like.

Examples of the post-transition metal halide may include a zinc halide (e.g., ZnF₂, ZnCl₂, ZnBr₂, ZnI₂, and/or the like), an indium halide (e.g., InI₃ and/or the like), a tin halide (e.g., SnI₂ and/or the like), and/or the like.

Examples of the lanthanide metal halide may include YbF, YbF₂, YbF₃, SmF₃, YbCl, YbCl₂, YbCl₃, SmCl₃, YbBr, YbBr₂, YbBr₃, SmBr₃, YbI, YbI₂, YbI₃, SmI₃, and/or the like.

Examples of the metalloid halide may include an antimony halide (e.g., SbCl₅ and/or the like) and/or the like.

Examples of the metal telluride may include an alkali metal telluride (e.g., Li₂Te, Na₂Te, K₂Te, Rb₂Te, Cs₂Te, and/or the like), an alkaline earth metal telluride (e.g., BeTe, MgTe, CaTe, SrTe, BaTe, and/or the like), a transition metal telluride (e.g., TiTe₂, ZrTe₂, HfTe₂, V₂Te₃, Nb₂Te₃, Ta₂Te₃, Cr₂Te₃, Mo₂Te₃, W₂Te₃, MnTe, TcTe, ReTe, FeTe, RuTe, OsTe, CoTe, RhTe, IrTe, NiTe, PdTe, PtTe, Cu₂Te, CuTe, Ag₂Te, AgTe, Au₂Te, and/or the like), a post-transition metal telluride (e.g., ZnTe and/or the like), a lanthanide metal telluride (e.g., LaTe, CeTe, PrTe, NdTe, PmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, and/or the like), and/or the like.

Emission Layer in Interlayer 130

When the light-emitting device 10 is a full color light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer, according to a sub-pixel. In one or more embodiments, the emission layer may have a stacked structure. The stacked structure may include two or more layers selected from a red emission layer, a green emission layer, and a blue emission layer. The two or more layers may be in direct contact (e.g., physical contact) with each other. In some embodiments, the two or more layers may be separated from each other. In one or more embodiments, the emission layer may include two or more materials. The two or more materials may include a red light-emitting material, a green light-emitting material, or a blue light-emitting material. The two or more materials may be mixed with each other in a single layer. The two or more materials mixed with each other in the single layer may be to emit white light.

The emission layer may include a host and a dopant. The dopant may be a phosphorescent dopant, a fluorescent dopant, or any combination thereof.

The emission layer may include the compound of Formula 1 and the compound of Formula 2 according to one or more embodiments. For example, the compound of Formula 1 and the compound of Formula 2 may each be (e.g., act as) a host.

In an embodiment, the emission layer in the light-emitting device may include a host and a dopant, and a content of the total host (e.g., a total amount of the host) included in the emission layer may be greater than a content of the total dopant (e.g., a total amount of the dopant) included in the emission layer.

For example, a content of the dopant (e.g., a total amount of the dopant) may be in a range of about 0.01 parts to about 30 parts by weight, based on 100 parts by weight of the total host (the compound of Formula 1+the compound of Formula 2, e.g., a total amount of the host). In some embodiments, a content of the dopant (e.g., a total amount of the dopant) may be in a range of about 0.01 parts to about 15 parts by weight, based on 100 parts by weight of the host.

The thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, and in some embodiments, about 200 Å to about 600 Å. When the thickness of the emission layer is within any of these ranges, improved luminescence characteristics may be obtained without a substantial increase in driving voltage.

Host

The host may include the compound of Formula 1 and the compound of Formula 2 according to one or more embodiments.

Phosphorescent Dopant

The phosphorescent dopant may include at least one transition metal as a center (central) metal.

The phosphorescent dopant may include a monodentate ligand, a bidentate ligand, a tridentate ligand, a tetradentate ligand, a pentadentate ligand, a hexadentate ligand, or any combination thereof.

The phosphorescent dopant may be electrically neutral.

In some embodiments, the phosphorescent dopant may include an organometallic complex represented by Formula 401:

M(L₄₀₁)_xc1(L₄₀₂)_xc2  Formula 401

wherein, in Formulae 401 and 402,

M may be transition metal (e.g., iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), gold (Au), hafnium (Hf), europium (Eu), terbium (Tb), rhodium (Rh), rhenium (Re), or thulium (Tm)),

L₄₀₁ may be a ligand represented by Formula 402, and xc1 may be 1, 2, or 3; and when xc1 is 2 or greater, at least two L₄₀₁(s) may be identical to or different from each other,

L₄₀₂ may be an organic ligand, and xc2 may be an integer from 0 to 4; and when xc2 is 2 or greater, at least two L₄₀₂(s) may be identical to or different from each other,

X₄₀₁ and X₄₀₂ may each independently be nitrogen or carbon,

ring A₄₀₁ and ring A₄₀₂ may each independently be a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group,

T₄₀₁ may be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₁)—*′, *—C(Q₄₁₁)(Q₄₁₂)*′, *—C(Q₄₁₁)═C(Q₄₁₂)—*′, *—C(Q₄₁₁)═*′, or *═C═*′,

X₄₀₃ and X₄₀₄ may each independently be a chemical bond (e.g., a covalent bond or a coordinate bond), O, S, N(Q₄₁₃), B(Q₄₁₃), P(Q₄₁₃), C(Q₄₁₃)(Q₄₁₄), or Si(Q₄₁₃)(Q₄₁₄),

Q₄₁₁ to Q₄₁₄ may each be understood by referring to the description of Q₁ provided herein,

R₄₀₁ and R₄₀₂ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀ alkyl group unsubstituted or substituted with at least one R_10a, a C₁-C₂₀ alkoxy group unsubstituted or substituted with at least one R_10a, a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), or —P(═O)(Q₄₀₁)(Q₄₀₂),

Q₄₀₁ to Q₄₀₃ may each be understood by referring to the description of Q₁ provided herein,

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

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

In one or more embodiments, in Formula 402, i) X₄₀₁ may be nitrogen, and X₄₀₂ may be carbon, or ii) X₄₀₁ and X₄₀₂ may both (e.g., simultaneously) be nitrogen.

In one or more embodiments, when xc1 in Formula 402 is 2 or greater, two ring A₄₀₁(s) of at least two L₄₀₁(s) may optionally be bound via T₄₀₂ as a linking group, or two ring A₄₀₂(s) may optionally be bound via T₄₀₃ as a linking group (see Compounds PD1 to PD4 and PD7). T₄₀₂ and T₄₀₃ may each be understood by referring to the description of T₄₀₁ provided herein.

L₄₀₂ in Formula 401 may be any suitable organic ligand. For example, L₄₀₂ may be a halogen group, a diketone group (e.g., an acetylacetonate group), a carboxylic acid group (e.g., a picolinate group), —C(═O), an isonitrile group, —CN, or a phosphorus group (e.g., a phosphine group or a phosphite group).

The phosphorescent dopant may be, for example, one of Compounds PD1 to PD39, Dopant (2), or any combination thereof:

Fluorescent Dopant

The fluorescent dopant may include an amine group-containing compound, a styryl group-containing compound, or any combination thereof.

In some embodiments, the fluorescent dopant may include a compound represented by Formula 501:

wherein, in Formula 501,

Ar₅₀₁, L₅₀₁ to L₅₀₃, R₅₀₁, and R₅₀₂ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a,

xd1 to xd3 may each independently be 0, 1, 2, or 3, and

xd4 may be 1, 2, 3, 4, 5, or 6.

In some embodiments, in Formula 501, Ar₅₀₁ may include a condensed ring group (e.g., an anthracene group, a chrysene group, or a pyrene group) in which at least three monocyclic groups are condensed.

In some embodiments, xd4 in Formula 501 may be 2.

In some embodiments, the fluorescent dopant may include one of Compounds FD1 to FD36, DPVBi, DPAVBi, or any combination thereof:

Delayed Fluorescence Material

The emission layer may include a compound represented by Formula 11:

wherein, in Formula 11,

As may be O, S, NR″₂₄, or CR″₂₅R″₂₆, A₇ may be O, S, NR″₂₇, or CR″₂₈R″₂₉, As may be O, S, NR″₃₀, or CR″₃₁R″₃₂, and A₉ may be O, S, NR″₃₃, or CR″₃₄R″₃₅,

R″₂₀ to R″₃₅ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group unsubstituted or substituted with at least one R_10a, a C₂-C₆₀ alkenyl group unsubstituted or substituted with at least one R_10a, a C₂-C₆₀ alkynyl group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ alkoxy group unsubstituted or substituted with at least one R_10a, a C₃-C₁₀ cycloalkyl group unsubstituted or substituted with at least one R_10a, a C₁-C₁₀ heterocycloalkyl group unsubstituted or substituted with at least one R_10a, a C₃-C₁₀ cycloalkenyl group unsubstituted or substituted with at least one R_10a, a C₁-C₁₀ heterocycloalkenyl group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ aryl group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ aryloxy group unsubstituted or substituted with at least one R_10a, a C₆-C₆₀ arylthio group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ heteroaryl group unsubstituted or substituted with at least one R_10a, a C₈-C₆₀ a monovalent non-aromatic condensed polycyclic group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ a monovalent non-aromatic condensed heteropolycyclic group unsubstituted or substituted with at least one R_10a, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and —P(═S)(Q₁)(Q₂),

b″₂₀ and b″₂₁ may each independently be an integer from 0 to 3, and

b″₂₂ and b″₂₃ may each independently be an integer from 0 to 4.

In Formula 11, when b″₂₀ is 2 or greater, at least two R″₂₀(s) may be identical to or different from each other. When b″₂₁ is 2 or greater, at least two R″₂₁(s) may be identical to or different from each other. When b″₂₂ is 2 or greater, at least two R″₂₂(s) may be identical to or different from each other. When b″₂₃ is 2 or greater, at least two R″₂₃(s) may be identical to or different from each other.

In Formula 11, two adjacent substituents in R₂₀ to R₃₅ may optionally be bound to each other to form a C₅-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a.

In some embodiments, the compound represented by Formula 11 may be one of the following compounds:

Quantum Dots

The term “quantum dot” as utilized herein refers to a crystal of a semiconductor compound, and may include any suitable material capable of emitting light wavelengths corresponding to the size of the crystal.

The diameter of the quantum dot may be, for example, in a range of about 1 nm to about 10 nm.

Quantum dots may be synthesized by a wet chemical process, an organic metal chemical vapor deposition process, a molecular beam epitaxy process, and/or any similar process.

A wet chemical process is a method of growing a quantum dot particle crystal by mixing a precursor material with an organic solvent. As the crystal grows, the organic solvent may naturally serve as a dispersant coordinated on the surface of the quantum dot crystal and may thereby control the growth of the crystal. Thus, the wet chemical method may be easier to perform than a vapor deposition process (such a metal organic chemical vapor deposition (MOCVD) and/or a molecular beam epitaxy (MBE) process). Further, the growth of quantum dot particles may be controlled with a lower manufacturing cost.

The quantum dot may include a group II-VI semiconductor compound; a group Ill-V semiconductor compound; a group Ill-VI semiconductor compound; a group I-III-VI semiconductor compound; a group IV-VI semiconductor compound; a group IV element or compound; or any combination thereof.

Examples of the group II-VI semiconductor compound may include a binary compound (such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, and/or MgS); a ternary compound (such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, and/or MgZnS); a quaternary compound (such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and/or HgZnSTe); or any combination thereof.

Examples of the group III-V semiconductor compound may include a binary compound (such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, and/or InSb); a ternary compound (such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, and/or InPSb); a quaternary compound (such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and/or InAlPSb); or any combination thereof. In some embodiments, the group III-V semiconductor compound may further include a group II element. Examples of the group III-V semiconductor compound further including the group II element may include InZnP, InGaZnP, InAlZnP, and/or the like.

Examples of the III-VI group semiconductor compound may include a binary compound (such as GaS, GaSe, Ga₂Se₃, GaTe, InS, InSe, In₂S₃, In₂Se₃, InTe, and/or the like); a ternary compound (such as InGaS₃, InGaSe₃, and/or the like); or any combination thereof.

Examples of the group I-III-VI semiconductor compound may include a ternary compound (such as AgInS, AgInS₂, CuInS, CuInS₂, CuGaO₂, AgGaO₂, AgAlO₂, or any combination thereof).

Examples of the group IV-VI semiconductor compound may include a binary compound (such as SnS, SnSe, SnTe, PbS, PbSe, and/or PbTe); a ternary compound (such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, and/or SnPbTe); a quaternary compound (such as SnPbSSe, SnPbSeTe, and/or SnPbSTe); or any combination thereof.

The group IV element or compound may be a single element material (such as Si and/or Ge); a binary compound (such as SiC and/or SiGe); or any combination thereof.

Individual elements included in the multi-element compound, (such as a binary compound, a ternary compound, and/or a quaternary compound), may be present in a particle thereof at a substantially uniform or non-substantially uniform concentration (e.g., distribution).

The quantum dot may have a single structure in which the concentration of each element included in the quantum dot is substantially uniform, or a core-shell double structure. In some embodiments, materials included in the core may be different from materials included in the shell.

The shell of the quantum dot may serve as a protective layer for preventing or reducing chemical denaturation of the core to maintain semiconductor characteristics, and/or as a charging layer for imparting electrophoretic characteristics to the quantum dot. The shell may be a monolayer or a multilayer. An interface between a core and a shell may have a concentration gradient where a concentration of elements present in the shell decreases toward the core.

Examples of the shell of the quantum dot may include a metal oxide, a metalloid oxide, a nonmetal oxide, a semiconductor compound, or a combination thereof. Examples of the metal oxide, metalloid oxide, or nonmetal oxide may include: a binary compound (such as SiO₂, Al₂O₃, TiO₂, ZnO, MnO, Mn₂O₃, Mn₃O₄, CuO, FeO, Fe₂O₃, Fe₃O₄, CoO, CO₃O₄, and/or NiO); a ternary compound (such as MgAl₂O₄, CoFe₂O₄, NiFe₂O₄, and/or CoMn₂O₄); and any combination thereof. Examples of the semiconductor compound may include a group II-VI semiconductor compound; a group III-V semiconductor compound; a group III-VI semiconductor compound; a group I-III-VI semiconductor compound; a group IV-VI semiconductor compound; or any combination thereof. In some embodiments, the semiconductor compound may be CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or any combination thereof.

The quantum dot may have a full width of half maximum (FWHM) of a spectrum of an emission wavelength of about 45 nm or less, about 40 nm or less, or about 30 nm or less. When the FWHM of the quantum dot is within this range, color purity or color reproducibility may be improved. In some embodiments, because light emitted through the quantum dot is emitted in all directions (or substantially all directions), an optical viewing angle may be improved.

In some embodiments, the quantum dot may be a spherical, pyramidal, multi-arm, and/or cubic nanoparticle, nanotube, nanowire, nanofiber, and/or nanoplate particle.

By adjusting the size of the quantum dot, the energy band gap may also be adjusted to thereby obtain light of various suitable wavelengths in the quantum dot emission layer. By utilizing quantum dots of one or more suitable sizes, a light-emitting device to emit light of one or more suitable wavelengths may be realized. In some embodiments, the size of the quantum dot may be selected such that the quantum dot may be to emit red, green, and/or blue light. In some embodiments, the size of the quantum dot may be selected such that the quantum dot may be to emit white light by combining one or more suitable light colors.

Electron Transport Region in Interlayer 130

The electron transport region may have i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) 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 include a hole blocking layer, an electron control layer, an electron transport layer, and/or an electron injection layer.

In some embodiments, 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 an electron transport layer/electron injection layer structure, wherein layers of each structure are sequentially stacked on the emission layer in each stated order.

The electron transport region (e.g., a hole blocking layer, an electron control layer, and/or an electron transport layer in the electron transport region) may include a metal-free compound including at least one π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group.

In some embodiments, the electron transport region may include a compound represented by Formula 601:

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

wherein, in Formula 601,

Ar₆₀₁ and L₆₀₁ may each independently be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a,

xe11 may be 1, 2, or 3,

xe1 may be 0, 1, 2, 3, 4, or 5,

R₆₀₁ may be a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a, a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a, —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), or —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁ to Q₆₀₃ may each be understood by referring to the description of Q₁ provided herein,

xe21 may be 1, 2, 3, 4, or 5, and

at least one of Ar₆₀₁, L₆₀₁, and R₆₀₁ may independently be a π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group unsubstituted or substituted with at least one R_10a.

In some embodiments, when xe11 in Formula 601 is 2 or greater, at least two Ar₆₀₁(s) may be bound via a single bond.

In some embodiments, in Formula 601, Ar₆₀₁ may be a substituted or unsubstituted anthracene group.

In some embodiments, the electron transport region may include a compound represented by Formula 601-1:

wherein, in Formula 601-1,

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N or C(R₆₁₆), at least one selected from X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ may each be understood by referring to the description of L₆₀₁ provided herein,

xe611 to xe613 may each be understood by referring to the description of xe1 provided herein,

R₆₁₁ to R₆₁₃ may each be understood by referring to the description of R₆₀₁ provided herein, and

R₆₁₄ to R₆₁₆ may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a C₃-C₆₀ carbocyclic group unsubstituted or substituted with at least one R_10a, or a C₁-C₆₀ heterocyclic group unsubstituted or substituted with at least one R_10a.

For example, in Formulae 601 and 601-1, xe1 and xe611 to xe613 may each independently be 0, 1, or 2.

The electron transport region may include one of Compounds ET1 to ET45, 2,9-dimethyl-4,7-diphenyl-1, 10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), AIq3, BAIq, TAZ, NTAZ, or any combination thereof:

The thickness of the electron transport region may be in a range of about 160 Angstroms (Å) to about 5,000 Å, for example, about 100 Å to about 4,000 Å. When the electron transport region includes a hole blocking layer, an electron control layer, an electron transport layer, or any combination thereof, the thicknesses of the hole blocking layer and the electron control layer may each independently be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å, and the thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When the thicknesses of the hole blocking layer, the electron control layer, the electron transport layer, and/or the electron transport layer are each within these ranges, excellent or suitable electron transport characteristics may be obtained without a substantial increase in driving voltage.

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

The metal-containing material may include an alkali metal complex, an alkaline earth metal complex, or any combination thereof. A metal ion of the alkali metal complex may be a lithium (Li) ion, a sodium (Na) ion, a potassium (K) ion, a rubidium (Rb) ion, or a cesium (Cs) ion. A metal ion of the alkaline earth metal complex may be a beryllium (Be) ion, a magnesium (Mg) ion, a calcium (Ca) ion, a strontium (Sr) ion, or a barium (Ba) ion. Each ligand coordinated with the metal ion of the alkali metal complex and the alkaline earth metal complex may independently be hydroxyquinoline, hydroxyisoquinoline, hydroxybenzoquinoline, hydroxyacridine, hydroxyphenanthridine, hydroxyphenyloxazole, hydroxyphenylthiazole, hydroxyphenyloxadiazole, hydroxyphenylthiadiazole, hydroxyphenylpyridine, hydroxyphenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline, cyclopentadiene, or any combination thereof.

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

The electron transport region may include an electron injection layer to facilitate injection of electrons from the second electrode 150. The electron injection layer may be in direct contact (e.g., physical contact) with the second electrode 150.

The electron injection layer may have i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) 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-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof.

The alkali metal may be Li, Na, K, Rb, Cs or any combination thereof. The alkaline earth metal may be Mg, Ca, Sr, Ba, or any combination thereof. The rare earth metal may be Sc, Y, Ce, Tb, Yb, Gd, or any combination thereof.

The alkali metal-containing compound, the alkaline earth metal-containing compound, and the rare earth metal-containing compound may respectively be or include oxides, halides (e.g., fluorides, chlorides, bromides, or iodides), tellurides, or any combination thereof of each of the alkali metal, the alkaline earth metal, and the rare earth metal.

The alkali metal-containing compound may be or include alkali metal oxides (such as Li₂O, Cs₂O, and/or K₂O), alkali metal halides (such as LiF, NaF, CsF, KF, LiI, NaI, CsI, and/or KI), or any combination thereof. The alkaline earth-metal-containing compound may include alkaline earth-metal oxides, (such as BaO, SrO, CaO, BaxSr_1-xO (wherein x is a real number satisfying 0<x<1), and/or BaxCa_1-xO (wherein x is a real number satisfying 0<x<1)). The rare earth metal-containing compound may include YbF₃, ScF₃, Sc₂O₃, Y₂O₃, Ce₂O₃, GdF₃, TbF₃, YbI₃, ScI₃, TbI₃, or any combination thereof. In some embodiments, the rare earth metal-containing compound may include a lanthanide metal telluride. Examples of the lanthanide metal telluride may include LaTe, CeTe, PrTe, NdTe, PmTe, SmTe, EuTe, GdTe, TbTe, DyTe, HoTe, ErTe, TmTe, YbTe, LuTe, La₂Te₃, Ce₂Te₃, Pr₂Te₃, Nd₂Te₃, Pm₂Te₃, Sm₂Te₃, Eu₂Te₃, Gd₂Te₃, Tb₂Te₃, Dy₂Te₃, Ho₂Te₃, Er₂Te₃, Tm₂Te₃, Yb₂Te₃, Lu₂Te₃, and/or the like.

The alkali metal complex, the alkaline earth metal complex, and the rare earth metal complex may include: i) a respective metal ion of the alkali metal, alkaline earth metal, and rare earth metal as described above, and ii) a ligand bonded to the metal ion, e.g., hydroxyquinoline, hydroxyisoquinoline, hydroxybenzoquinoline, hydroxyacridine, hydroxyphenanthridine, hydroxyphenyloxazole, hydroxyphenylthiazole, hydroxyphenyloxadiazole, hydroxyphenylthiadiazole, hydroxyphenylpyridine, hydroxyphenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline, cyclopentadiene, or any combination thereof.

The electron injection layer may include (e.g., consist of) an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal-containing compound, an alkaline earth metal-containing compound, a rare earth metal-containing compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof, as described above. In some embodiments, the electron injection layer may further include an organic material (e.g., a compound represented by Formula 601).

In some embodiments, the electron injection layer may include (e.g., consist of) i) an alkali metal-containing compound (e.g., alkali metal halide), or ii) a) an alkali metal-containing compound (e.g., alkali metal halide); and b) an alkali metal, an alkaline earth metal, a rare earth metal, or any combination thereof. In some embodiments, the electron injection layer may be a KI:Yb co-deposition layer, a RbI:Yb co-deposition layer, and/or the like.

When the electron injection layer further includes an organic material, the alkali metal, the alkaline earth metal, the rare earth metal, the alkali metal-containing compound, the alkaline earth metal-containing compound, the rare earth metal-containing compound, the alkali metal complex, the alkaline earth metal complex, the rare earth metal complex, or any combination thereof may be substantially homogeneously or non-homogeneously dispersed in a matrix including (e.g., formed of) the organic material.

The thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, and in some embodiments, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within any of these ranges, excellent or suitable electron injection characteristics may be obtained without a substantial increase in driving voltage.

Second Electrode 150

The second electrode 150 may be on the interlayer 130. In an embodiment, the second electrode 150 may be a cathode that is an electron injection electrode. In this embodiment, a material for forming the second electrode 150 may be a material having a low work function, for example, a metal, an alloy, an electrically conductive compound, or any combination thereof.

The second electrode 150 may include lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ytterbium (Yb), silver-ytterbium (Ag—Yb), ITO, IZO, or any combination thereof. The second electrode 150 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode 150 may have a single-layered structure, or a multi-layered structure including two or more layers.

Capping Layer

A first capping layer may be located outside the first electrode 110, and/or a second capping layer may be located outside the second electrode 150. In some embodiments, the light-emitting device 10 may have a structure in which the first capping layer, the first electrode 110, the interlayer 130, and the second electrode 150 are sequentially stacked in this stated order, a structure in which the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are sequentially stacked in this stated order, or a structure in which the first capping layer, the first electrode 110, the interlayer 130, the second electrode 150, and the second capping layer are sequentially stacked in this stated order.

In the light-emitting device 10, light emitted from the emission layer in the interlayer 130 may pass through the first electrode 110 (which may be a semi-transmissive electrode or a transmissive electrode) and through the first capping layer to the outside. In the light-emitting device 10, light emitted from the emission layer in the interlayer 130 may pass through the second electrode 150 (which may be a semi-transmissive electrode or a transmissive electrode) and through the second capping layer to the outside.

The first capping layer and the second capping layer may improve the external luminescence efficiency based on the principle of constructive interference. Accordingly, the optical extraction efficiency of the light-emitting device 10 may be increased, thus improving the luminescence efficiency of the light-emitting device 10.

The first capping layer and the second capping layer may each include a material having a refractive index of 1.6 or higher (at a wavelength of 589 nm).

The first capping layer and the second capping layer may each independently be a capping layer including an organic material, an inorganic capping layer including an inorganic material, or an organic-inorganic composite capping layer including an organic material and an inorganic material.

At least one of the first capping layer and the second capping layer may each independently include carbocyclic compounds, heterocyclic compounds, amine group-containing compounds, porphine derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, alkali metal complexes, alkaline earth metal complexes, or any combination thereof. The carbocyclic compound, the heterocyclic compound, and the amine group-containing compound may optionally be substituted with a substituent of O, N, S, Se, Si, F, Cl, Br, I, or any combination thereof. In some embodiments, at least one of the first capping layer and the second capping layer may each independently include an amine group-containing compound.

In some embodiments, at least one of the first capping layer and the second capping layer may each independently include the compound represented by Formula 201, the compound represented by Formula 202, or any combination thereof.

In one or more embodiments, at least one of the first capping layer and the second capping layer may each independently include one of Compounds HT28 to HT33 one of Compounds CP1 to CP6, β-NPB, or any combination thereof:

Electronic Apparatus

The light-emitting device may be included in one or more suitable electronic apparatuses. In some embodiments, an electronic apparatus including the light-emitting device may be an emission apparatus and/or an authentication apparatus.

The electronic apparatus (e.g., an emission apparatus) may further include, in addition to the light-emitting device, i) a color filter, ii) a color-conversion layer, or iii) a color filter and a color-conversion layer. The color filter and/or the color-conversion layer may be disposed on at least one traveling direction of light emitted from the light-emitting device. For example, light emitted from the light-emitting device may be blue light or white light. The light-emitting device may be understood by referring to the descriptions provided herein. In some embodiments, the color-conversion layer may include quantum dots.

The electronic apparatus may include a first substrate. The first substrate may include a plurality of sub-pixel areas, the color filter may include a plurality of color filter areas respectively corresponding to the plurality of sub-pixel areas, and the color-conversion layer may include a plurality of color-conversion areas respectively corresponding to the plurality of sub-pixel areas.

A pixel-defining film may be located between the plurality of sub-pixel areas to define each sub-pixel area.

The color filter may further include a plurality of color filter areas and light-blocking patterns between the plurality of color filter areas, and the color-conversion layer may further include a plurality of color-conversion areas and light-blocking patterns between the plurality of color-conversion areas.

The plurality of color filter areas (or a plurality of color-conversion areas) may include: a first area to emit a first color light; a second area to emit a second color light; and/or a third area to emit a third color light, and the first color light, the second color light, and/or the third color light may have different maximum emission wavelengths. In some embodiments, the first color light may be red light, the second color light may be green light, and the third color light may be blue light. In some embodiments, the plurality of color filter areas (or the plurality of color-conversion areas) may each include quantum dots. In some embodiments, the first area may include red quantum dots, the second area may include green quantum dots, and the third area may not include a quantum dot. The quantum dot may be understood by referring to the description of the quantum dot provided herein. The first area, the second area, and/or the third area may each further include an emitter.

In some embodiments, the light-emitting device may be to emit a first light, the first area may be to absorb the first light to emit a 1-1 color light, the second area may be to absorb the first light to emit a 2-1 color light, and the third area may be to absorb the first light to emit (e.g., to transmit) a 3-1 color light. In this embodiment, the 1-1 color light, the 2-1 color light, and the 3-1 color light may each have a different maximum emission wavelength. In some embodiments, the first light may be blue light, the 1-1 color light may be red light, the 2-1 color light may be green light, and the 3-1 light may be blue light.

The electronic apparatus may further include a thin-film transistor, in addition to the light-emitting device. The thin-film transistor may include a source electrode, a drain electrode, and an active layer, wherein one of the source electrode or the drain electrode may be electrically connected to one of the first electrode or the second electrode of the light-emitting device.

The thin-film transistor may further include a gate electrode, a gate insulating film, and/or the like.

The active layer may include a crystalline silicon, an amorphous silicon, an organic semiconductor, and/or an oxide semiconductor.

The electronic apparatus may further include an encapsulation unit for sealing the light-emitting device. The encapsulation unit may be located between the color filter and the light-emitting device and/or between the color-conversion layer and the light-emitting device. The encapsulation unit may allow light to pass to the outside from the light-emitting device and/or prevent or reduce permeation of air and/or moisture to the light-emitting device at the same time (e.g., simultaneously). The encapsulation unit may be a sealing substrate including a transparent glass and/or a plastic substrate. The encapsulation unit may be a thin-film encapsulating layer including at least one of an organic layer and/or an inorganic layer. When the encapsulation unit is a thin-film encapsulating layer, the electronic apparatus may be flexible.

In addition to the color filter and/or the color-conversion layer, one or more suitable functional layers may be disposed on the encapsulation unit depending on the intended use of an electronic apparatus. Examples of the functional layer may include a touch screen layer, a polarization layer, and/or the like. The touch screen layer may include a resistive touch screen layer, a capacitive touch screen layer, and/or an infrared beam touch screen layer. The authentication apparatus may be, for example, a biometric authentication apparatus that identifies an individual according to biometric information (e.g., a fingertip, a pupil, and/or the like).

The authentication apparatus may further include a biometric information collecting unit, in addition to the light-emitting device described above.

The electronic apparatus may be applicable to various suitable displays, an optical source, lighting, a personal computer (e.g., a mobile personal computer), a cellphone, a digital camera, an electronic note, an electronic dictionary, an electronic game console, a medical device (e.g., an electronic thermometer, a blood pressure meter, a glucometer, a pulse measuring device, a pulse wave measuring device, an electrocardiograph recorder, an ultrasonic diagnosis device, or an endoscope display device), a fish finder, various suitable measurement devices, gauges (e.g., gauges of an automobile, an airplane, and/or a ship), and a projector.

Descriptions of FIGS. 2 and 3

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

An emission apparatus in FIG. 2 may include a substrate 100, a thin-film transistor, a light-emitting device, and an encapsulation unit 300 sealing the light-emitting device.

The substrate 100 may be a flexible substrate, a glass substrate, and/or a metal substrate. A buffer layer 210 may be on the substrate 100. The buffer layer 210 may prevent or reduce penetration of impurities through the substrate 100 and provide a flat surface on the substrate 100.

A thin-film transistor may be on the buffer layer 210. The thin-film transistor may include an active layer 220, a gate electrode 240, a source electrode 260, and a drain electrode 270.

The active layer 220 may include an inorganic semiconductor (such as silicon and/or polysilicon), an organic semiconductor, or an oxide semiconductor, and may include a source area, a drain area, and a channel area.

A gate insulating film 230 for insulating the active layer 220 and the gate electrode 240 may be on the active layer 220, and the gate electrode 240 may be on the gate insulating film 230.

An interlayer insulating film 250 may be on the gate electrode 240. The interlayer insulating film 250 may be between the gate electrode 240 and the source electrode 260 and between the gate electrode 240 and the drain electrode 270 to provide insulation therebetween.

The source electrode 260 and the drain electrode 270 may be on the interlayer insulating film 250. The interlayer insulating film 250 and the gate insulating film 230 may be formed to expose the source area and the drain area of the active layer 220, and the source electrode 260 and the drain electrode 270 may be adjacent to the exposed source area and the exposed drain area of the active layer 220.

Such a thin-film transistor may be electrically connected to a light-emitting device to drive the light-emitting device, and may be protected by a passivation layer 280. The passivation layer 280 may include an inorganic insulating film, an organic insulating film, or a combination thereof. A light-emitting device may be on the passivation layer 280. The light-emitting device may include a first electrode 110, an interlayer 130, and a second electrode 150.

The first electrode 110 may be on the passivation layer 280. The passivation layer 280 may not fully cover the drain electrode 270 and may expose a set or predetermined area of the drain electrode 270, and the first electrode 110 may be disposed to connect to the exposed area of the drain electrode 270.

A pixel-defining film 290 may be on the first electrode 110. The pixel-defining film 290 may expose a specific area of the first electrode 110, and the interlayer 130 may be formed in the exposed area. The pixel-defining film 290 may be a polyimide and/or polyacryl organic film. In some embodiments, some higher layers of the interlayer 130 may extend to the upper portion of the pixel-defining film 290 and may be disposed in the form of a common layer.

The second electrode 150 may be on the interlayer 130, and a capping layer 170 may be additionally formed on the second electrode 150. The capping layer 170 may be formed to cover the second electrode 150.

The encapsulation unit 300 may be on the capping layer 170. The encapsulation unit 300 may be on the light-emitting device to protect a light-emitting device from moisture and/or oxygen. The encapsulation unit 300 may include: an inorganic film including silicon nitride (SiN_x), silicon oxide (SiO_x), indium tin oxide, indium zinc oxide, or any combination thereof; an organic film including PET, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, polyarylate, hexamethyl disiloxane, an acrylic resin (e.g., polymethylmethacrylate, polyacrylic acid, and/or the like), an epoxy resin (e.g., aliphatic glycidyl ether (AGE) and/or the like), or any combination thereof; or a combination of the inorganic film and the organic film.

FIG. 3 is a schematic cross-sectional view of another light-emitting apparatus according to an embodiment.

The emission apparatus shown in FIG. 3 may be substantially identical to the emission apparatus shown in FIG. 2, except that a light-shielding pattern 500 and a functional area 400 are additionally located on the encapsulation unit 300. The functional area 400 may be i) a color filter area, ii) a color-conversion area, or iii) a combination of a color filter area and a color-conversion area. In some embodiments, the light-emitting device shown in FIG. 3 included in the emission apparatus may be a tandem light-emitting device.

Manufacturing Method

The layers constituting the hole transport region, the emission layer, and the layers constituting the electron transport region may each be formed in a set or predetermined region by utilizing one or more suitable methods (such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser printing, and/or laser-induced thermal imaging).

When the layers constituting the hole transport region, the emission layer, and the layers constituting the electron transport region are each independently formed by vacuum-deposition, the vacuum-deposition may be performed at a deposition temperature in a range of about 100° C. to about 500° C., at a vacuum degree in a range of about 10⁻⁸ torr to about 10⁻³ torr, and at a deposition rate in a range of about 0.01 Angstroms per second (Å/sec) to about 100 Å/sec, depending on the material to be included in each layer and the structure of each layer to be formed.

General Definitions of Terms

The term “C₃-C₆₀ carbocyclic group” as utilized herein refers to a cyclic group consisting of carbon atoms only and having 3 to 60 carbon atoms as ring-forming atoms. The term “C₁-C₆₀ heterocyclic group” as utilized herein refers to a cyclic group having 1 to 60 carbon atoms in addition to a heteroatom as ring-forming atoms other than carbon atoms. The C₃-C₆₀ carbocyclic group and the C₁-C₆₀ heterocyclic group may each be a monocyclic group consisting of one ring or a polycyclic group in which at least two rings are condensed. For example, the number of ring-forming atoms in the C₁-C₆₀ heterocyclic group may be in a range of 3 to 61.

The term “cyclic group” as utilized herein may include the C₃-C₆₀ carbocyclic group and the C₁-C₆₀ heterocyclic group.

The term “π electron-rich C₃-C₆₀ cyclic group” refers to a cyclic group having 3 to 60 carbon atoms and not including *—N═*′ as a ring-forming moiety. The term “π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group” as utilized herein refers to a heterocyclic group having 1 to 60 carbon atoms and *—N═*′ as a ring-forming moiety.

In some embodiments,

the C₃-C₆₀ carbocyclic group may be i) a T1 group (defined below) or ii) a group in which at least two T1 groups are condensed (for example, a cyclopentadiene group, an adamantane group, a norbornane group, a benzene group, a pentalene group, a naphthalene group, an azulene group, an indacene group, an acenaphthylene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a perylene group, a pentaphene group, a heptalene group, a naphthacene group, a picene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, an indene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, an indenophenanthrene group, or an indenoanthracene group),

the C₁-C₆₀ heterocyclic group may be i) a T2 group (defined below), ii) a group in which at least two T2 groups are condensed, or iii) a group in which at least one T2 group is condensed with at least one T1 group (for example, a pyrrole group, a thiophene group, a furan group, an indole group, a benzoindole group, a naphthoindole group, an isoindole group, a benzoisoindole group, a naphthoisoindole group, a benzosilole group, a benzothiophene group, a benzofuran group, a carbazole group, a dibenzosilole group, a dibenzothiophene group, a dibenzofuran group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a benzoindolocarbazole group, a benzocarbazole group, a benzonaphthofuran group, a benzonapthothiophene group, a benzonaphthosilole group, a benzofurodibenzofuran group, a benzofurodibenzothiophene group, a benzothienodibenzothiophene group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzoisoxazole group, a benzothiazole group, a benzoisothiazole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a benzoquinazoline group, a phenanthroline group, a cinnoline group, a phthalazine group, a naphthyridine group, an imidazopyridine group, an imidazopyrimidine group, an imidazotriazine group, an imidazopyrazine group, an imidazopyridazine group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzothiophene group, an azadibenzofuran group, and/or the like),

the π electron-rich C₃-C₆₀ cyclic group may be i) a T1 group, ii) a condensed group in which at least two T1 groups are condensed, iii) a T3 group (defined below), iv) a condensed group in which at least two T3 groups are condensed, or v) a condensed group in which at least one T3 group is condensed with at least one T1 group (for example, a C₃-C₆₀ carbocyclic group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, a thiophene group, a furan group, an indole group, a benzoindole group, a naphthoindole group, an isoindole group, a benzoisoindole group, a naphthoisoindole group, a benzosilole group, a benzothiophene group, a benzofuran group, a carbazole group, a dibenzosilole group, a dibenzothiophene group, a dibenzofuran group, an indenocarbazole group, an indolocarbazole group, a benzofurocarbazole group, a benzothienocarbazole group, a benzosilolocarbazole group, a benzoindolocarbazole group, a benzocarbazole group, a benzonaphthofuran group, a benzonapthothiophene group, a benzonaphthosilole group, a benzofurodibenzofuran group, a benzofurodibenzothiophene group, a benzothienodibenzothiophene group, and/or the like), and

the π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group may be i) a T4 group (defined below), ii) a group in which at least two T4 groups are condensed, iii) a group in which at least one T4 group is condensed with at least one T1 group, iv) a group in which at least one T4 group is condensed with at least one T3 group, or v) a group in which at least one T4 group, at least one T1 group, and at least one T3 group are condensed (for example, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzoisoxazole group, a benzothiazole group, a benzoisothiazole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a benzoisoquinoline group, a quinoxaline group, a benzoquinoxaline group, a quinazoline group, a benzoquinazoline group, a phenanthroline group, a cinnoline group, a phthalazine group, a naphthyridine group, an imidazopyridine group, an imidazopyrimidine group, an imidazotriazine group, an imidazopyrazine group, an imidazopyridazine group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzothiophene group, an azadibenzofuran group, and/or the like),

wherein the T1 group may be a cyclopropane group, a cyclobutane group, a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclooctane group, a cyclobutene group, a cyclopentene group, a cyclopentadiene group, a cyclohexene group, a cyclohexadiene group, a cycloheptene group, an adamantane group, a norbornane (or bicyclo[2.2.1]heptane) group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.2]octane group, or a benzene group,

the T2 group may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, a borole group, a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a tetrazine group, a pyrrolidine group, an imidazolidine group, a dihydropyrrole group, a piperidine group, a tetrahydropyridine group, a dihydropyridine group, a hexahydropyrimidine group, a tetrahydropyrimidine group, a dihydropyrimidine group, a piperazine group, a tetrahydropyrazine group, a dihydropyrazine group, a tetrahydropyridazine group, or a dihydropyridazine group,

the T3 group may be a furan group, a thiophene group, a 1H-pyrrole group, a silole group, or a borole group, and

the T4 group may be a 2H-pyrrole group, a 3H-pyrrole group, an imidazole group, a pyrazole group, a triazole group, a tetrazole group, an oxazole group, an isoxazole group, an oxadiazole group, a thiazole group, an isothiazole group, a thiadiazole group, an azasilole group, an azaborole group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, or a tetrazine group.

The terms “cyclic group”, “C₃-C₆₀ carbocyclic group”, “C₁-C₆₀ heterocyclic group”, “π electron-rich C₃-C₆₀ cyclic group”, and/or “π electron-deficient nitrogen-containing C₁-C₆₀ cyclic group” as utilized herein may each refer to a group condensed with any suitable cyclic group, a monovalent group, or a polyvalent group (e.g., a divalent group, a trivalent group, a quadrivalent group, and/or the like), depending on the structure of the formula to which the term is applied. For example, a “benzene group” may be or refer to a benzene ring, a phenyl group, a phenylene group, and/or the like, as understood by one of ordinary skill in the art depending on the structure of the formula including the “benzene group”.

Examples of the monovalent C₃-C₆₀ carbocyclic group and the monovalent C₁-C₆₀ heterocyclic group may include a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group. Examples of the divalent C₃-C₆₀ carbocyclic group and the monovalent C₁-C₆₀ heterocyclic group may include a C₃-C₁₀ cycloalkylene group, a C₁-C₁₀ heterocycloalkylene group, a C₃-C₁₀ cycloalkenylene group, a C₁-C₁₀ heterocycloalkenylene group, a C₆-C₆₀ arylene group, a C₁-C₆₀ heteroarylene group, a divalent non-aromatic condensed polycyclic group, and/or a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group.

The term “C₁-C₆₀ alkyl group” as utilized herein refers to a linear or branched aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms, and examples thereof may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an iso-nonyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, and/or a tert-decyl group. The term “C₁-C₆₀ alkylene group” as utilized herein refers to a divalent group having substantially the same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group” as utilized herein refers to a hydrocarbon group having at least one carbon-carbon double bond at a main chain (e.g., in the middle) or at a terminal end (e.g., the terminus) of the C₂-C₆₀ alkyl group. Examples thereof may include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group” as utilized herein refers to a divalent group having substantially the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as utilized herein refers to a monovalent hydrocarbon group having at least one carbon-carbon triple bond at a main chain (e.g., in the middle) or at a terminal end (e.g., the terminus) of the C₂-C₆₀ alkyl group. Examples thereof may include an ethynyl group and/or a propynyl group. The term “C₂-C₆₀ alkynylene group” as utilized herein refers to a divalent group having substantially the same structure as the C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group” as utilized herein refers to a monovalent group represented by —OA₁₀₁ (wherein A₁₀₁ is a C₁-C₁ alkyl group). Examples thereof may include a methoxy group, an ethoxy group, and/or an isopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group” as utilized herein refers to a monovalent saturated hydrocarbon monocyclic group including 3 to 10 carbon atoms. Examples of the C₃-C₁₀ cycloalkyl group as utilized herein may include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantanyl group, a norbornanyl (bicyclo[2.2.1]heptyl) group, a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, and/or a bicyclo[2.2.2]octyl group. The term “C₃-C₁₀ cycloalkylene group” as utilized herein refers to a divalent group having the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as utilized herein refers to a monovalent cyclic group including at least one heteroatom other than carbon atoms as a ring-forming atom and having 1 to 10 carbon atoms. Examples thereof may include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and/or a tetrahydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group” as utilized herein refers to a divalent group having substantially the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group” as utilized herein refers to a monovalent cyclic group that has 3 to 10 carbon atoms and at least one carbon-carbon double bond in its ring, and is not aromatic. Examples thereof may include a cyclopentenyl group, a cyclohexenyl group, and/or a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” as utilized herein refers to a divalent group having substantially the same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as utilized herein refers to a monovalent cyclic group including at least one heteroatom other than carbon atoms as a ring-forming atom, 1 to 10 carbon atoms, and at least one double bond in its ring. Examples of the C₁-C₁₀ heterocycloalkenyl group may include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group” as utilized herein refers to a divalent group having substantially the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₆-C₆₀ aryl group” as utilized herein refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. The term “C₆-C₆₀ arylene group” as utilized herein refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Examples of the C₆-C₆₀ aryl group may include a phenyl group, a pentalenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a heptalenyl group, a naphthacenyl group, a picenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, and/or an ovalenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene group each independently include two or more rings, the respective rings may be fused.

The term “C₁-C₆₀ heteroaryl group” as utilized herein refers to a monovalent group having a heterocyclic aromatic system further including at least one heteroatom other than carbon atoms as a ring-forming atom and 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group” as utilized herein refers to a divalent group having a heterocyclic aromatic system further including at least one heteroatom other than carbon atoms as a ring-forming atom and 1 to 60 carbon atoms. Examples of the C₁-C₆₀ heteroaryl group may include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, a benzoquinolinyl group, an isoquinolinyl group, a benzoisoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, a benzoquinazolinyl group, a cinnolinyl group, a phenanthrolinyl group, a phthalazinyl group, a naphthyridinyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a 1H-indolyl group, a benzoindolyl group, a naphthoindolyl group, an isoindolyl group, a benzoisoindolyl group, a naphthoisoindolyl group, a benzothiophenyl group, a benzofuranyl group, a carbazolyl group, a dibenzothiophenyl group, a dibenzofuranyl group, an azacarbazolyl group, an azadibenzothiophenyl group, an azadibenzofuranyl group, a pyrazolyl group, an imidazolyl group, a triazolyl group, a tetrazolyl group, an oxazolyl group, an isoxazolyl group, a thiazolyl group, an isothiazolyl group, an oxadiazolyl group, a thiadiazolyl group, a benzopyrazolyl group, a benzimidazolyl group, a benzoxazolyl group, a benzothiazolyl group, a benzoxadiazolyl group, a benzothiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an imidazotriazinyl group, an imidazopyrazinyl group, an imidazopyridazinyl group, an indolocarbazolyl group, a benzofurocarbazolyl group, a benzothienocarbazolyl group, a benzoindolocarbazolyl group, a benzocarbazolyl group, a benzonaphthofuranyl group, a benzonaphthothiophenyl group, a benzofurodibenzofuranyl group, a benzofurodibenzothiophenyl group, and/or a benzothienodibenzothiophenyl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group each independently include two or more rings, the respective rings may be fused.

The term “monovalent non-aromatic condensed polycyclic group” as utilized herein refers to a monovalent group that has two or more condensed rings and only carbon atoms (e.g., 8 to 60 carbon atoms) as ring forming atoms, wherein the molecular structure when considered as a whole is non-aromatic (e.g., no aromatic conjugation system extends across the entire structure, although portions of the group may contain conjugated systems). Examples of the monovalent non-aromatic condensed polycyclic group may include an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, and/or an indenoanthracenyl group. The term “divalent non-aromatic condensed polycyclic group” as utilized 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 utilized herein refers to a monovalent group that has two or more condensed rings and at least one heteroatom other than carbon atoms (e.g., 1 to 60 carbon atoms), as a ring-forming atom, wherein the molecular structure when considered as a whole is non-aromatic (e.g., no aromatic conjugation system extends across the entire structure, although portions of the group may contain conjugated systems). Examples of the monovalent non-aromatic condensed heteropolycyclic group include a 3H-indolyl group, a benzosilolyl group, a dibenzosilolyl group, an azafluorenyl group, an azadibenzosilolyl group, an indenocarbazolyl group, a benzosilolocarbazolyl group, and/or a benzonaphthosilolyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as utilized herein refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C₆-C₆₀ aryloxy group” as utilized herein indicates —OA₁₀₂ (wherein A₁₀₂ is a C₆-C₆₀ aryl group), and a C₆-C₆₀ arylthio group as utilized herein indicates —SA₁₀₃ (wherein A₁₀₃ is a C₆-C₆₀ aryl group).

The term “C₇-C₆₀ aryl alkyl group” utilized herein refers to -A₁₀₄A₁₀₅ (where A₁₀₄ may be a C₁-C₅₄ alkylene group, and A₁₀₅ may be a C₆-C₅₉ aryl group), and the term “C₂-C₆₀ heteroaryl alkyl group” utilized herein refers to -A₁₀₆A₁₀₇ (where A₁₀₆ may be a C₁-C₅₉ alkylene group, and A₁₀₇ may be a C₁-C₅₉ heteroaryl group).

The term “R_10a” as utilized herein may be:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, a C₂-C₆₀ heteroaryl alkyl group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), —P(═O)(Q₁₁)(Q₁₂), or any combination thereof;

a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, or a C₂-C₆₀ heteroaryl alkyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₆₀ carbocyclic group, a C₁-C₆₀ heterocyclic group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ aryl alkyl group, a C₂-C₆₀ heteroaryl alkyl group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), —P(═O)(Q₂₁)(Q₂₂), or any combination thereof; or

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

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently be: hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; a C₁-C₆₀ alkyl group; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group, each unsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, or any combination thereof; a C₇-C₆₀ aryl alkyl group; or a C₂-C₆₀ heteroaryl alkyl group.

The term “heteroatom” as utilized herein refers to any atom other than a carbon atom. Examples of the heteroatom may include O, S, N, P, Si, B, Ge, Se, or any combination thereof.

A third-row transition metal as utilized herein may include hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), or gold (Au).

“Ph” utilized herein represents a phenyl group, “Me” utilized herein represents a methyl group, “Et” utilized herein represents an ethyl group, “ter-Bu” or “Bu^t” utilized herein represents a tert-butyl group, and “OMe” utilized herein represents a methoxy group.

The term “biphenyl group” as utilized herein refers to a phenyl group substituted with a phenyl group. The “biphenyl group” belongs to a substituted phenyl group having a C₆-C₆₀ aryl group as a substituent.

The term “terphenyl group” as utilized herein refers to a phenyl group substituted with a biphenyl group. The “terphenyl group” belongs to “a substituted phenyl group” having a “C₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group” as a substituent.

The maximum number of carbon atoms in the definitions herein are illustrative only. For example, the maximum number of carbon atoms in the C₁-C₆₀ alkyl group of 60 may in some embodiments also be applied to the C₁-C₂₀ alkyl group. Further, the minimum number of carbon atoms in the definitions, for example, 12 in the C₁₂-C₆₀ heteroaryl group may in some embodiments also be applied to other groups such as the heteroaryl group. Other cases may also be the same.

The symbols * and *′ as utilized herein, unless defined otherwise, refer to a binding site to an adjacent atom in a corresponding formula or moiety.

Hereinafter, compounds and a light-emitting device according to one or more embodiments will be described in more detail with reference to Synthesis Examples and Examples. The wording “B was utilized instead of A” utilized in describing Synthesis Examples indicates that an amount of B utilized was identical to an amount of A utilized in terms of molar equivalents.

EXAMPLES

Synthesis Example 1: Synthesis of Compound ET-01

3-bromo-9-phenyl-9H-carbazole (1 eq.) and 2-phenyl-1H-benz[d]imidazole (1.2 eq.) were added to a flask, and then Pd(dba)₃ (0.06 eq.), (t-Bu)₃P (0.09 eq.), t-BuONa (4.4 eq.), and toluene (0.1 molar (M) 1 eq. based on reagent) were added to the flask, followed by stirring under reflux for 24 hours.

Subsequently, the mixture was cooled to room temperature, followed by extraction utilizing methylene chloride (MC) and washing with distilled water. The resulting mixture was dried utilizing MgSO₄, distilled under reduced pressure, and the residue was separated through column chromatography, thereby obtaining Compound ET-01 (yield: 90.3%). Compound ET-01 was identified utilizing liquid chromatography-mass spectrometry (LC-MS).

(C31H21N3: [M]⁺436.86)

Synthesis Example 2: Synthesis of Compound ET-02

1) Synthesis of Intermediate [int-1]

3,6-dibromo-9-phenyl-9H-carbazole (1 eq.) and 2-phenyl-1H-benzo[d]imidazole (1.2 eq.) were added to a flask, and then Pd(dba)₃ (0.06 eq.), (t-Bu)₃P (0.09 eq.), t-BuONa (4.4 eq.), and toluene (0.1 M 1 eq.) were added to the flask, followed by stirring under reflux for 24 hours.

Subsequently, the mixture was cooled to room temperature, followed by extraction utilizing MC and washing with distilled water. The resulting mixture was dried utilizing MgSO₄, distilled under reduced pressure, and the residue was separated through column chromatography, thereby obtaining Intermediate 1 (yield: 80.9%). Intermediate 1 was identified by LC-MS.

(C31H20BrN3:[M]⁺514.40)

2) Synthesis of Compound ET-02

Intermediate 1 (int-1) (1 eq.) and CuCN (1.8 eq.) were added to a flask. Then, N-methyl-2-pyrrolidone (0.15 M 1 eq. based on reagent) was added to the flask, followed by stirring under reflux for 72 hours.

Subsequently, the mixture was cooled to room temperature, followed by extraction utilizing MC and washing with distilled water. The resulting mixture was dried utilizing MgSO₄, distilled under reduced pressure, and the residue was separated through column chromatography, thereby obtaining Compound ET-02 (yield: 71.9%). Compound ET-02 was identified utilizing LC-MS.

(C32H20N4:[M]⁺461.33)

Compounds synthesized in the Synthesis Examples were identified by ¹H nuclear magnetic resonance (NMR) and mass spectroscopy/fast atom bombardment (MS/FAB). The results thereof are shown in Table 1.

Methods of synthesizing additional compounds, including compounds other than those shown in Table 1, may be easily understood by those skilled in the art by referring to the synthesis schemes and raw materials described above.

	TABLE 1
	MS/FAB
Compound	1H NMR (CDCl3, 400 MHz)	found	calc.
ET-01	7.14(t, 1H), 7.21-7.38(m, 3H), 7.50-	436.86	435.53
	7.65(m, 10H), 7.80 (d, 1H), 7.93-
	7.98(m, 2H), 8.30(d, 2H), 8.50-8.55(m,
	2H)
ET-02	7.25-7.35(m, 3H), 7.50-7.65(m, 10H),	461.33	460.54
	7.80-7.83 (m, 2H), 7.98(s, 1H),
	8.12(t, 1H), 8.29(d, 2H), 8.56(d, 1H)

Manufacture of Organic Light-Emitting Devices

Example 1

An ITO glass substrate was cut to a size of 50 millimeters (mm)×50 mm×0.5 mm, sonicated in isopropyl alcohol and pure water for 10 minutes in each solvent, and cleaned by exposure to ultraviolet rays with ozone for 10 minutes to utilize the glass substrate as an anode. Then, the glass substrate was mounted to a vacuum-deposition apparatus.

m-MTDATA was vacuum-deposited on the substrate to form a hole injection layer to a thickness of 40 Å. Subsequently, NPB having hole transportability was vacuum-deposited thereon to form a hole transport layer to a thickness of 10 Å.

HT-01 and ET-01 as hosts at a weight ratio of 5:5 and Dopant(1)-1 as a dopant were co-deposited on the hole transport layer to form an emission layer having a thickness of 300 Å (doping ratio of 10 parts by weight based on the 100 parts weight of the hosts)).

Then, ETL1 was deposited on the emission layer to form an electron transport layer to a thickness of 300 Å, and Al was vacuum-deposited thereon to a thickness of 1,200 Å to form an Al electrode (cathode), thereby completing the manufacture of an organic light-emitting device.

Example 2

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compound HT-05 was utilized instead of Compound HT-01 in the formation of an emission layer.

Example 3

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compound HT-18 was utilized instead of Compound HT-01 in the formation of an emission layer.

Example 4

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compound HT-19 was utilized instead of Compound HT-01 in the formation of an emission layer.

Example 5

An organic light-emitting device was manufactured in substantially the same manner as in Example 4, except that Compound ET-02 was utilized instead of Compound ET-01 in the formation of an emission layer.

Example 6

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compounds HT-20 and ET-04 were utilized instead of Compounds HT-01 and ET-01 in the formation of an emission layer.

Example 7

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compounds HT-22 and ET-07 were utilized instead of Compounds HT-01 and ET-01 in the formation of an emission layer.

Example 8

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Dopant (2) was utilized instead of Dopant(1)-1 in the formation of an emission layer.

Example 9

An organic light-emitting device was manufactured in substantially the same manner as in Example 2, except that Dopant (2) was utilized instead of Dopant(1)-1 in the formation of an emission layer.

Example 10

An organic light-emitting device was manufactured in substantially the same manner as in Example 3, except that Dopant (2) was utilized instead of Dopant(1)-1 in the formation of an emission layer.

Example 11

An organic light-emitting device was manufactured in substantially the same manner as in Example 4, except that Dopant (2) was utilized instead of Dopant(1)-1 in the formation of an emission layer.

Example 12

An organic light-emitting device was manufactured in substantially the same manner as in Example 5, except that Dopant (2) was utilized instead of Dopant(1)-1 in the formation of an emission layer.

Example 13

An organic light-emitting device was manufactured in substantially the same manner as in Example 6, except that Dopant (2) was utilized instead of Dopant(1)-1 in the formation of an emission layer.

Example 14

An organic light-emitting device was manufactured in substantially the same manner as in Example 7, except that Dopant (2) was utilized instead of Dopant(1)-1 in the formation of an emission layer.

Comparative Example 1

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that only 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP) was utilized as a host, and Dopant(1)-1 was utilized as a dopant in the formation of an emission layer.

Comparative Example 2

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that only Compound HT-18 was utilized as a host, and Dopant(1)-1 was utilized as a dopant in the formation of an emission layer.

Comparative Example 3

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that only Compound ET-01 was utilized as a host, and Dopant(1)-1 was utilized as a dopant in the formation of an emission layer.

Comparative Example 4

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compound 10 was utilized instead of Compound HT-01 in the formation of an emission layer.

Comparative Example 5

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compound 200 was utilized instead of Compound ET-01 in the formation of an emission layer.

Comparative Example 6

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that only CBP was utilized as a host, and Dopant(2) was utilized as a dopant in the formation of an emission layer.

Comparative Example 7

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that only Compound HT-18 was utilized as a host, and Dopant(2) was utilized as a dopant in the formation of an emission layer.

Comparative Example 8

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that only Compound ET-01 was utilized as a host, and Dopant(2) was utilized as a dopant in the formation of an emission layer.

Comparative Example 9

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compound 100 was utilized instead of Compound HT-01, and Dopant(2) was utilized as a dopant in the formation of an emission layer.

Comparative Example 10

An organic light-emitting device was manufactured substantially in the same manner as in Example 1, except that Compound 200 was utilized instead of Compound ET-01, and Dopant(2) was utilized as a dopant in the formation of an emission layer.

The driving voltage (V), efficiency, and maximum emission wavelength (nm) of the organic light-emitting devices of Examples 1 to 14 and Comparative Examples 1 to 10 at a luminance of 1,000 cd/m² to evaluate characteristics thereof.

The driving voltage (V), luminescence efficiency (cd/A), maximum emission wavelength (nm), and lifespan (LT₉₅) of the organic light-emitting devices at a luminance of 1,000 cd/m² were measured by utilizing a Keithley source-measure unit (SMU) 236 and a luminance meter PR650. The results thereof are shown in Table 2. In Table 2, the lifespan (LT₉₀) indicates a time (hour) for the luminance of each light-emitting device to decline to 90% of its initial luminance.

	TABLE 2
				Efficiency	Lifespan
	Dopant	Host-1	Host-2	(cd/A)	(T90)
Example 1	Dopant(1)-	HT-01	ET-01	22.1	35.1
	1
Example 2	Dopant(1)-	HT-05	ET-01	23.5	34.2
	1
Example 3	Dopant(1)-	HT-18	ET-01	25.1	45.3
	1
Example 4	Dopant(1)-	HT-19	ET-01	26.5	44.2
	1
Example 5	Dopant(1)-	HT-19	ET-02	23.7	39.1
	1
Example 6	Dopant(1)-	HT-20	ET-04	24.8	39.8
	1
Example 7	Dopant(1)-	HT-22	ET-07	24.7	40.5
	1
Example 8	Dopant(2)	HT-01	ET-01	23.1	36.9
Example 9	Dopant(2)	HT-05	ET-01	24.2	38.1
Example 10	Dopant(2)	HT-18	ET-01	26.9	42.3
Example 11	Dopant(2)	HT-19	ET-01	28.1	42.5
Example 12	Dopant(2)	HT-19	ET-02	27.7	43.2
Example 13	Dopant(2)	HT-20	ET-04	28.1	45.3
Example 14	Dopant(2)	HT-22	ET-07	26.7	42.8
Comparative	Dopant(1)-	CBP	—	16.1	8.2
Example 1	1
Comparative	Dopant(1)-	HT-18	—	20.1	15.4
Example 2	1
Comparative	Dopant(1)-	—	ET-01	12.1	10.2
Example 3	1
Comparative	Dopant(1)-	100	ET-01	20.1	29.4
Example 4	1
Comparative	Dopant(1)-	HT-01	200	21.3	19.7
Example 5	1
Comparative	Dopant(2)	CBP	—	21.2	17.2
Example 6
Comparative	Dopant(2)	HT-18	—	11.1	15.3
Example 7
Comparative	Dopant(2)	—	ET-01	10.1	11.2
Example 8
Comparative	Dopant(2)	100	ET-01	18.1	31.2
Example 9
Comparative	Dopant(2)	HT-01	200	17.4	33.4
Example 10

Referring to the results of Table 2, the organic light-emitting device of Examples 1 and 2 were found to have improved characteristics, as compared with the organic light-emitting devices of Comparative Examples 1 and 2.

When a carbazole group is substituted at a C-position (carbon) of an imidazole group, π-conjugation may be extended from the imidazole group to the carbazole group, thereby lowering LUMO energy (e.g., due to delocalization). When a carbazole group is substituted at an N-position of an imidazole group, the LUMO may be present only in (e.g., may be localized on) the imidazole group, thus resulting in a high LUMO energy, compared with a case where the carbazole group is substituted at a C-position. Accordingly, Host-1 and Host-2 may form an exciplex with a high energy, thus improving energy transfer to dopants, and thereby realizing a light-emitting device having high efficiency.

As apparent from the foregoing description, the light-emitting device according to one or more embodiments may have excellent or suitable efficiency and/or lifespan.

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. “About” or “approximately,” as used herein, is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (e.g., the limitations of the measurement system). For example, “about” may mean within one or more standard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

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.

It should be understood that the 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 typically be considered as being available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the drawings, it will be understood by those of ordinary skill in the art that various suitable 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.

Claims

1. A light-emitting device comprising: a first electrode;a second electrode facing the first electrode; andan interlayer between the first electrode and the second electrode and comprising an emission layer,wherein the emission layer comprises:a compound represented by Formula 1; anda compound represented by Formula 2:

2. The light-emitting device of claim 1, wherein the first electrode is an anode, the second electrode is a cathode, and the interlayer further comprises: a hole transport region comprising a hole injection layer, a hole transport layer, an electron blocking layer, or any combination thereof; oran electron transport region comprising a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

3. The light-emitting device of claim 1, wherein the emission layer comprises a first host having hole transportability and a second host having electron transportability, the first host comprises the compound represented by Formula 1, andthe second host comprises the compound represented by Formula 2.

4. The light-emitting device of claim 3, wherein a weight ratio of the first host to the second host is in a range of about 1:9 to about 9:1.

5. The light-emitting device of claim 1, wherein L1 in Formula 1 is a C6-C60 arylene group unsubstituted or substituted with at least one R10a, and R1 and R2 are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, or a C1-C60 heteroaryl group unsubstituted or substituted with at least one R10a.

6. The light-emitting device of claim 1, wherein L2 and L3 in Formula 2 are each independently a single bond or a phenylene group unsubstituted or substituted with at least one R10a, and Ar5 and Ar6 are bound to each other to form a C3-C60 carbocyclic group unsubstituted or substituted with at least one R10a or a C1-C60 heterocyclic group unsubstituted or substituted with at least one R10a.

7. The light-emitting device of claim 1, wherein Ar2 and Ar3 in Formula 2 are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, or a nitro group, and Ar1 and Ar4 are each independently a C6-C60 aryl group unsubstituted or substituted with at least one R10a or a C1-C60 heteroaryl group unsubstituted or substituted with at least one R10a.

8. The light-emitting device of claim 1, wherein Ar′ in Formula 1 and Ar1 to Ar6 in Formula 2 each independently comprise a cyano group, moieties 1 to 24, or a combination thereof:

9. The light-emitting device of claim 1, wherein the compound represented by Formula 1 is one of the following compounds:

10. The light-emitting device of claim 1, wherein the compound represented by Formula 2 is one of the following compounds:

11. The light-emitting device of claim 1, wherein the emission layer comprises a fluorescent dopant, and the fluorescent dopant is a compound represented by Formula 11:

12. The light-emitting device of claim 1, wherein the emission layer comprises a phosphorescent dopant, and the phosphorescent dopant is a compound represented by Formula 401: M(L401)xc1(L402)xc2  Formula 401

13. An electronic apparatus comprising the light-emitting device of claim 1.

14. The electronic apparatus of claim 13, further comprising a capping layer outside the first electrode and/or the second electrode.

15. The electronic apparatus of claim 14, wherein the capping layer comprises a material having a refractive index of 1.6 or greater at a wavelength of 589 nanometers (nm).

16. The electronic apparatus of claim 13, further comprising a thin-film transistor, wherein the thin-film transistor comprises a source electrode and a drain electrode, and the first electrode of the light-emitting device is electrically connected to at least one of the source electrode or the drain electrode of the thin-film transistor.

17. The electronic apparatus of claim 13, further comprising a color filter, a color-conversion layer, a touchscreen layer, a polarization layer, or any combination thereof.

18. The electronic apparatus of claim 17, wherein the color-conversion layer comprises quantum dots.

19. A compound represented by Formula 2:

20. The electronic apparatus of claim 19, wherein Formula 2 is a compound represented by Formula 3: