LIGHT-EMITTING ELEMENT, FUSED POLYCYCLIC COMPOUND FOR THE LIGHT-EMITTING ELEMENT, AND DISPLAY DEVICE INCLUDING THE LIGHT-EMITTING ELEMENT

Abstract

A light-emitting element including a first electrode, a second electrode on the first electrode, and an emission layer between the first electrode and the second electrode is provided. The light-emitting layer includes a fused polycyclic compound having a pentacyclic core that includes three aromatic rings fused by one boron and two nitrogen atoms. A first substituent that excludes hydrogen and deuterium is connected to the pentacyclic core at an ortho-position of the boron.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0072084, filed on Jun. 5, 2023, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.

BACKGROUND

1. Field

The present disclosure herein relates to a light-emitting element, a fused polycyclic compound for the light-emitting element, and a display device including the light-emitting element.

2. Description of the Related Art

Recently, the development of an organic electroluminescence display device as an image display device is being actively conducted. The organic electroluminescence display device and/or the like is a display device including a so-called “self-luminescent” type or kind light-emitting element, in which holes and electrons, respectively, injected from a first electrode and a second electrode, are combined in an emission layer of the display device. Subsequently, a light-emitting material of the emission layer (e.g., light-emitting layer) emits light to accomplish (e.g., implement) display, (e.g., of an image).

Implementation of a light-emitting element to display devices requires (or there is a desire for), improvements in light efficiency, lifespan, and the like. Therefore, the need or desire exists for the development of materials for a light-emitting element capable of stably achieving such characteristics or desires.

SUMMARY

One or more aspects of embodiments of the present disclosure is directed toward a light-emitting element having improved light efficiency and lifespan and a display device including the same.

One or more aspects of embodiments of the present disclosure is directed toward a fused polycyclic compound which is a light-emitting element material that improves light efficiency and lifespan.

One or more embodiments of the present disclosure provides a light-emitting element including a first electrode, a second electrode provided on the first electrode, and an emission layer provided between the first electrode and the second electrode and including a first compound represented by Formula 1.

In Formula 1, at least one of X₁ or X₂ may be a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted germanium (Ge) group, a substituted or unsubstituted selenium (Se) group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms, any (e.g., possible) remaining one of X₁ or X₂ may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted germanium group, a substituted or unsubstituted selenium group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms, Y₁ to Y₈ may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms, R₁ to R₅, R_b1 to R_b4, and R_c1 to R_c6 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms, n1 to n4 may each independently be an integer of 0 to 5, and R_a may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or is represented by Formula 2.

In Formula 2, Y₁₁ to Y₁₈ may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms.

In one or more embodiments, the emission layer may further include at least one of a second compound represented by Formula HT-1, a third compound represented by Formula ET-1, or a fourth compound represented by Formula D-1.

In Formula HT-1, A₁ to A₈ may each independently be N or CR₅₁, L1 may be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms, Y₈ may be a direct linkage, CR₅₂R₅₃, or SiR₅₄R₅₅, Ar₁ may be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and R₅₁ to R₅₅ may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms, and/or are bonded to an adjacent group to form a ring.

In Formula ET-1, X₁₁ to X₁₃ may each be N or CR₅₆ and at least one X₁₁ to X₁₃ may be N, R₅₆ may be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms, b₁ to b₃ may each independently be an integer of 0 to 10, Ar₂ to Ar₄ may each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and L2 to L4 may each independently be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms.

In Formula D-1, Q₁ to Q₄ may each independently be C or N, C1 to C4 may each independently be a substituted or unsubstituted hydrocarbon ring having 5 to 30 ring-forming carbon atoms, or a substituted or unsubstituted hetero ring having 2 to 30 ring-forming carbon atoms, L11 to L13 may each independently be a direct linkage,

a substituted or unsubstituted divalent alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms, b11 to b13 may each independently be 0 or 1, R₆₁ to R₆₆ may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms, and d1 to d4 may each independently be an integer of 0 to 4.

In one or more embodiments, Formula 1 may be represented by one of Formulas 1-1 or 1-2.

In Formula 1-2, R_a1 may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms or a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, and, in Formulas 1-1 and 1-2, X₁, X₂, Y₁ to Y₈, Y₁₁ to Y₁₈, R₁ to R₅, R_b1 to R_b4, R_c1 to R_c6, and n1 to n4 may each independently be as defined in Formula 1.

In one or more embodiments, Formula 1-1 may be represented by one of Formulas 1-1A or 1-1B.

In Formula 1-1B, Y_3a and Y_13a may each independently be a cyano group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbazole group, and in Formulas 1-1A and 1-1B, D may be a deuterium atom, and X₁, X₂, R₁ to R₅, R_b1 to R₄, R_c1 to R_c6, and n1 to n4 may each independently be as defined in Formula 1-1.

In one or more embodiments, in Formula 1-2, R_a1 may be a deuterium atom, or represented by at least one of A-1 to A-4.

In one or more embodiments, in Formula 1, at least one of X₁ or X₂ may be a halogen atom or a cyano group, or represented by at least one of X-1 to X-41.

where, in X-2 and X-33, D may be a deuterium atom.

In one or more embodiments, in Formula 1, at least one of X₁ or X₂ (e.g., at least one selected from among X₁ and X₂) may be a halogen atom, a cyano group, a substituted or unsubstituted diphenylamine group, a substituted or unsubstituted methoxy group, a substituted or unsubstituted phenol group, a substituted or unsubstituted methylthio group, a substituted or unsubstituted germanium group, a substituted or unsubstituted selenium group, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, a substituted or unsubstituted isopropyl group, a substituted or unsubstituted n-propyl group, a substituted or unsubstituted i-butyl group, a substituted or unsubstituted s-butyl group, a substituted or unsubstituted t-pentyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrene group, a substituted or unsubstituted anthracene group, a substituted or unsubstituted thiophene group, a substituted or unsubstituted fluorene group, a substituted or unsubstituted pyridine group, a substituted or unsubstituted carbazole group, a substituted or unsubstituted dibenzofuran group, a substituted or unsubstituted dibenzothiophene group, or a substituted or unsubstituted dibenzoselenophene group.

In one or more embodiments, in Formula 1, R₃ may be a substituted or unsubstituted methyl group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted carbazole group, or a substituted or unsubstituted dibenzofuran group.

In one or more embodiments, in Formula 1, R_c2 and R_c5 may each independently be a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.

In one or more embodiments of the present disclosure, a fused polycyclic compound represented by Formula 1 is provided.

In one or more embodiments, a spin-orbit coupling (SOC) constant may be about 0.3 cm⁻¹ or more.

In one or more embodiments of the present disclosure, a display device includes a base layer, a circuit layer provided on the base layer, and a display element layer provided on the circuit layer and including a light-emitting element, wherein the light-emitting element includes a first electrode, a second electrode provided on the first electrode, and an emission layer provided between the first electrode and the second electrode and including a fused polycyclic compound represented by Formula 1.

In one or more embodiments, the light-emitting element may include a first light-emitting element configured to emit red light, a second light-emitting element configured to emit green light, and a third light-emitting element configured to emit blue light, and the fused polycyclic compound may be included in the third light-emitting element.

In one or more embodiments, the light-emitting element may be configured to emit blue light.

In one or more embodiments, the display device may further include a light control layer provided on the display element layer and including quantum dots.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the present disclosure and, together with the description, serve to explain principles of the present disclosure. In the drawings:

FIG. 1 is a plan view illustrating a display device according to one or more embodiments of the present disclosure;

FIG. 2 is a cross-sectional view illustrating a section taken along line I-I′ in FIG. 1;

FIG. 3 is a cross-sectional view schematically illustrating a light-emitting element according to one or more embodiments of the present disclosure;

FIG. 4 is a cross-sectional view schematically illustrating a light-emitting element according to one or more embodiments of the present disclosure;

FIG. 5 is a cross-sectional view schematically illustrating a light-emitting element according to one or more embodiments of the present disclosure;

FIG. 6 is a cross-sectional view schematically illustrating a light-emitting element according to one or more embodiments of the present disclosure;

FIG. 7 is a cross-sectional view schematically illustrating a light-emitting element according to one or more embodiments of the present disclosure;

FIG. 8 is a cross-sectional view illustrating a display device according to one or more embodiments of the present disclosure;

FIG. 9 is a cross-sectional view illustrating a display device according to one or more embodiments of the present disclosure;

FIG. 10 is a cross-sectional view illustrating a display device according to one or more embodiments of the present disclosure;

FIG. 11 is a cross-sectional view illustrating a display device according to one or more embodiments of the present disclosure; and

FIG. 12 is a view illustrating an inside of a vehicle, in which a display device according to one or more embodiments of the present disclosure is provided.

DETAILED DESCRIPTION

In the present disclosure, one or more suitable modifications can be made, one or more suitable forms can be utilized, and specific embodiments will be illustrated in the drawings and described in more detail in the text. However, this is not intended to limit the present disclosure to a specific form disclosed, and it will be understood that all changes, equivalents, or substitutes which fall in the spirit and technical scope of the present disclosure should be included.

In this specification, it will be understood that when an element (or region, layer, portion, and/or the like) is referred to as being “on”, “connected to” or “coupled to” another element, it can be directly on, connected or coupled to the other element, or intervening elements may be present.

Like reference numerals refer to like elements throughout, and duplicative descriptions thereof may not be provided. In some embodiments, in the drawings, the thicknesses, ratios, and dimensions of elements are exaggerated for effective description of the technical contents. As utilized herein, the term “and/or” includes any and all combinations that the associated configurations can define.

It will be understood that, although the terms first, second, and/or the like may be utilized herein to describe one or more suitable elements, these elements should not be limited by these terms. These terms are only utilized to distinguish one element from another element. For example, a first element could be termed a second element without departing from the scope of the present disclosure. Similarly, the second element may also be referred to as the first element. The terms of a singular form include plural forms unless otherwise specified. For example, “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

As utilized herein, the terms “use,” “using,” and “used” may be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively.

As utilized herein, expressions such as “at least one of,” “one of,” “selected from,” and “selected from among,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, the expressions “at least one of a to c,” “at least one of a, b or c,” and “at least one of a, b and/or c” may indicate only a, only b, only c, both (e.g., simultaneously) a and b, both (e.g., simultaneously) a and c, both (e.g., simultaneously) b and c, all of a, b, and c, or variations thereof.

The term “and/or” includes all combinations of one or more of the associated listed elements.

In the present application, when a layer, a film, a region, or a plate is referred to as being “on” or “in an upper portion of” another layer, film, region, or plate, it may be not only “directly on” the layer, film, region, or plate, but intervening layers, films, regions, or plates may also be present. On the contrary to this, when a layer, a film, a region, or a plate is referred to as being “in a lower portion of” another layer, film, region, or plate, it can be not only directly under the layer, film, region, or plate, but intervening layers, films, regions, or plates may also be present. In some embodiments, it will be understood that when a part is referred to as being “on” another part, it can be provided above the other part, or provided under the other part as well. The terms, such as “lower”, “above”, “upper” and/or the like, are utilized herein for ease of description to describe one element's relation to another element(s) as illustrated in the drawings. The terms are relative concepts and are described based on the directions indicated in the drawings. It will be understood that the terms have a relative concept and are described on the basis of the orientation depicted in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the drawings is turned over, elements described as “beneath” other elements or features would then be oriented “above” or “over” the other elements or features. Thus, the term “beneath” may encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

It will be understood that the terms “include” “includes,” “including,” “comprise,” “comprises”, “comprising,” “has,” “having,” and/or “have”, when utilized in this specification, specify the presence of stated features, integers, steps, operations, elements, components and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

As utilized herein, the term “may” will be understood to refer to “one or more embodiments of the present disclosure,” some of which include the described element and some of which exclude that element and/or include an alternate element. Similarly, alternative language such as “or” refers to “one or more embodiments of the present disclosure,” each including a corresponding listed item.

Unless otherwise defined, all terms (including chemical, technical and scientific terms) utilized herein have the same meaning as commonly understood by one of ordinary skill in the art to which this present disclosure belongs. It will be further understood that terms, such as those defined in commonly utilized dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As utilized herein, the phrase “consisting essentially of” means that any additional components will not materially affect the chemical, physical, optical, or electrical properties of the semiconductor film.

As utilized herein, the phrase “on a plane,” or “plan view,” refers to viewing a target portion from the top, and the phrase “on a cross-section” means viewing a cross-section formed by vertically cutting a target portion from the side.

In present disclosure, “not include a or any ‘component’” “exclude a or any ‘component’”, “‘component’-free”, and/or the like refers to that the “component” not being added, selected or utilized as a component in the composition, but the “component” of less than a suitable amount may still be included due to other impurities and/or external factor.

Definitions

In the specification, the term “substituted or unsubstituted” may refer to substituted or unsubstituted with at least one substituent selected from the group consisting of a deuterium atom, a halogen atom, a cyano group, a nitro group, an amino group, a silyl group, an oxy group, a thio group, a sulfinyl group, a sulfonyl group, a carbonyl group, a boron group, a phosphine oxide group, a phosphine sulfide group, an alkyl group, an alkenyl group, an alkynyl group, a hydrocarbon ring group, an aryl group, and a heterocyclic group. In some embodiments, each of the substituents exemplified may be substituted or unsubstituted. For example, a biphenyl group may be interpreted as an aryl group or a phenyl group substituted with a phenyl group.

In the specification, the phrase “bonded to an adjacent group to form a ring” may refer to that a group is bonded to an adjacent group to form a substituted or unsubstituted hydrocarbon ring, or a substituted or unsubstituted heterocycle. The hydrocarbon ring includes an aliphatic hydrocarbon ring and an aromatic hydrocarbon ring. The heterocycle includes an aliphatic heterocycle and an aromatic heterocycle. The hydrocarbon ring and the heterocycle may be monocyclic or polycyclic. In some embodiments, the rings formed by being bonded to each other may be connected to another ring to form a spiro structure.

In the specification, the term “adjacent group” may refer to a substituent substituted for an atom which is directly linked to an atom substituted with a corresponding substituent, another substituent substituted for an atom which is substituted with a corresponding substituent, or a substituent sterically positioned at the nearest position to a corresponding substituent. For example, two methyl groups in 1,2-dimethylbenzene may be interpreted as “adjacent groups” to each other and two ethyl groups in 1,1-diethylcyclopentane may be interpreted as “adjacent groups” to each other. In some embodiments, two methyl groups in 4,5-dimethylphenanthrene may be interpreted as “adjacent groups” to each other.

In the specification, examples of the halogen atom may include a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

In the specification, the alkyl group may be linear or branched. The number of carbons in the alkyl group is 1 to 60, 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of the alkyl group may include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, a t-butyl group, an i-butyl group, a 2-ethylbutyl group, a 3,3-dimethylbutyl group, an n-pentyl group, an i-pentyl group, a neopentyl group, a t-pentyl group, a 1-methylpentyl group, a 3-methylpentyl group, a 2-ethylpentyl group, a 4-methyl-2-pentyl group, an n-hexyl group, a 1-methylhexyl group, a 2-ethylhexyl group, a 2-butylhexyl group, an n-heptyl group, a 1-methylheptyl group, a 2,2-dimethylheptyl group, a 2-ethylheptyl group, a 2-butylheptyl group, an n-octyl group, a t-octyl group, a 2-ethyloctyl group, a 2-butyloctyl group, a 2-hexyloctyl group, a 3,7-dimethyloctyl group, an n-nonyl group, an n-decyl group, an adamantyl group, a 2-ethyldecyl group, a 2-butyldecyl group, a 2-hexyldecyl group, a 2-octyldecyl group, an n-undecyl group, an n-dodecyl group, a 2-ethyldodecyl group, a 2-butyldodecyl group, a 2-hexyldocecyl group, a 2-octyldodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, a 2-ethylhexadecyl group, a 2-butylhexadecyl group, a 2-hexylhexadecyl group, a 2-octylhexadecyl group, an n-heptadecyl group, an n-octadecyl group, an n-nonadecyl group, an n-eicosyl group, a 2-ethyleicosyl group, a 2-butyleicosyl group, a 2-hexyleicosyl group, a 2-octyleicosyl group, an n-henicosyl group, an n-docosyl group, an n-tricosyl group, an n-tetracosyl group, an n-pentacosyl group, an n-hexacosyl group, an n-heptacosyl group, an n-octacosyl group, an n-nonacosyl group, an n-triacontyl group, and/or the like, but the embodiment of the present disclosure is not limited thereto.

In the specification, a cycloalkyl group may refer to a cyclic alkyl group. The number of carbons in the cycloalkyl group is 3 to 50, 3 to 30, 3 to 20, or 3 to 10. Examples of the cycloalkyl group may include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a 4-methylcyclohexyl group, a 4-t-butylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a norbornyl group, a 1-adamantyl group, a 2-adamantyl group, an isobornyl group, a bicycloheptyl group, and/or the like, but the embodiment of the present disclosure is not limited thereto.

In the specification, an alkenyl group refers to a hydrocarbon group including at least one carbon double bond in the middle or terminal of an alkyl group having 2 or more carbon atoms. The alkenyl group may be linear or branched. The number of carbon atoms in the alkenyl group is not specifically limited, but is 2 to 60, 2 to 30, 2 to 20, or 2 to 10. Examples of the alkenyl group include a vinyl group, a 1-butenyl group, a 1-pentenyl group, a 1,3-butadienyl aryl group, a styrenyl group, a styryl vinyl group, and/or the like, but the embodiment of the present disclosure is not limited thereto.

In the specification, an alkynyl group refers to a hydrocarbon group including at least one carbon triple bond in the middle or terminal of an alkyl group having 2 or more carbon atoms. The alkynyl group may be linear or branched. Although the number of carbon atoms is not specifically limited, it is 2 to 30, 2 to 20, or 2 to 10. Specific examples of the alkynyl group may include an ethynyl group, a propynyl group, and/or the like, but are not limited thereto.

In the specification, the hydrocarbon ring group refers to any functional group or substituent derived from an aliphatic hydrocarbon ring. The hydrocarbon ring group may be a saturated hydrocarbon ring group having 5 to 20 ring-forming carbon atoms.

In the specification, an aryl group refers to any functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group may be a monocyclic aryl group or a polycyclic aryl group. The number of ring-forming carbon atoms in the aryl group may be 6 to 60, 6 to 30, 6 to 20, or 6 to 15. Examples of the aryl group may include a phenyl group, a naphthyl group, a fluorenyl group, an anthracenyl group, a phenanthryl group, a biphenyl group, a terphenyl group, a quaterphenyl group, a quinquephenyl group, a sexiphenyl group, a triphenylenyl group, a pyrenyl group, a benzofluoranthenyl group, a chrysenyl group, and/or the like, but the embodiment of the present disclosure is not limited thereto.

In the specification, the fluorenyl group may be substituted, and two substituents may be bonded to each other to form a spiro structure. Examples of the substituted fluorenyl group are as follows. However, the embodiment of the present disclosure is not limited thereto.

The heterocyclic group herein refers to any functional group or substituent derived from a ring containing at least one of B, O, N, P, Si, S or Se as a heteroatom. The heterocyclic group includes an aliphatic heterocyclic group and an aromatic heterocyclic group. The aromatic heterocyclic group may be a heteroaryl group. The aliphatic heterocycle and the aromatic heterocycle may be monocyclic or polycyclic.

In the specification, the heterocyclic group may contain at least one of B, O, N, P, Si, S or Se as a heteroatom. When the heterocyclic group contains two or more heteroatoms, the two or more heteroatoms may be the same as or different from each other. The heterocyclic group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group, and includes a heteroaryl group. The number of ring-forming carbon atoms in the heterocyclic group may be 2 to 60, 2 to 30, 2 to 20, or 2 to 10.

In the specification, the aliphatic heterocyclic group may include at least one of B, O, N, P, Si, S or Se as a heteroatom. The number of ring-forming carbon atoms in the aliphatic heterocyclic group may be 2 to 60, 2 to 30, 2 to 20, or 2 to 10. Examples of the aliphatic heterocyclic group may include an oxirane group, a thiirane group, a pyrrolidine group, a piperidine group, a tetrahydrofuran group, a tetrahydrothiophene group, a thiane group, a tetrahydropyran group, a 1,4-dioxane group, and/or the like, but the embodiment of the present disclosure is not limited thereto.

In the specification, the heteroaryl group may contain at least one of B, O, N, P, Si, S or Se as a heteroatom. When the heteroaryl group contains two or more heteroatoms, the two or more heteroatoms may be the same as or different from each other. The heteroaryl group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group. The number of ring-forming carbon atoms in the heteroaryl group may be 2 to 60, 2 to 30, 2 to 20, or 2 to 10. Examples of the heteroaryl group may include a thiophene group, a furan group, a pyrrole group, an imidazole group, a pyridine group, a bipyridine group, a pyrimidine group, a triazine group, a triazole group, an acridyl group, a pyridazine group, a pyrazinyl group, a quinoline group, a quinazoline group, a quinoxaline group, a phenoxazine group, a phthalazine group, a pyrido pyrimidine group, a pyrido pyrazine group, a pyrazino pyrazine group, an isoquinoline group, an indole group, a carbazole group, an N-arylcarbazole group, an N-heteroarylcarbazole group, an N-alkylcarbazole group, a benzoxazole group, a benzimidazole group, a benzothiazole group, a benzocarbazole group, a benzothiophene group, a dibenzothiophene group, a thienothiophene group, a benzofuran group, a phenanthroline group, a thiazole group, an isoxazole group, an oxazole group, an oxadiazole group, a thiadiazole group, a phenothiazine group, a dibenzosilole group, a dibenzofuran group, a dibenzoselenophene group, and/or the like, but the embodiment of the present disclosure is not limited thereto.

In the specification, the description of the aryl group may be applied to an arylene group except that the arylene group is a divalent group. The description of the heteroaryl group may be applied to a heteroarylene group except that the heteroarylene group is a divalent group.

In the specification, the silyl group includes an alkylsilyl group and an arylsilyl group. Examples of the silyl group may include a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, a propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, a phenylsilyl group, and/or the like, but the embodiment of the present disclosure is not limited thereto.

In the specification, the number of ring-forming carbon atoms in the carbonyl group is not specifically limited, but may be 1 to 40, 1 to 30, or 1 to 20. For example, the carbonyl group may have the following structures, but the embodiment of the present disclosure is not limited thereto.

In the specification, the number of carbon atoms in the sulfinyl group and the sulfonyl group is not particularly limited, but may be 1 to 30. The sulfinyl group may include an alkyl sulfinyl group and an aryl sulfinyl group. The sulfonyl group may include an alkyl sulfonyl group and an aryl sulfonyl group.

In the specification, the thio group may include an alkylthio group and an arylthio group. The thio group may refer to that a sulfur atom is bonded to the alkyl group or the aryl group as defined. Examples of the thio group may include a methylthio group, an ethylthio group, a propylthio group, a pentylthio group, a hexylthio group, an octylthio group, a dodecylthio group, a cyclopentylthio group, a cyclohexylthio group, a phenylthio group, a naphthylthio group, but the embodiment of the present disclosure is not limited thereto.

In the specification, an oxy group may refer to that an oxygen atom is bonded to the alkyl group or the aryl group as defined. The oxy group may include an alkoxy group and an aryl oxy group. The alkoxy group may be a linear chain, a branched chain or a ring chain. The number of carbon atoms in the alkoxy group is not specifically limited, but may be, for example, 1 to 20 or 1 to 10. Examples of the oxy group may include methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, octyloxy, nonyloxy, decyloxy, benzyloxy, and/or the like, but the embodiment of the present disclosure is not limited thereto.

The boron group herein may refer to that a boron atom is bonded to the alkyl group or the aryl group as defined. The boron group includes an alkyl boron group and an aryl boron group. Examples of the boron group may include a dimethylboron group, a trimethylboron group, a t-butyldimethylboron group, a diphenylboron group, a phenylboron group, and/or the like, but the embodiment of the present disclosure is not limited thereto.

In the specification, the number of carbon atoms in an amine group is not specifically limited, but may be 1 to 30. The amine group may include an alkyl amine group and an aryl amine group. Examples of the amine group may include a methylamine group, a dimethylamine group, a phenylamine group, a diphenylamine group, a naphthylamine group, a 9-methyl-anthracenylamine group, and/or the like, but the embodiment of the present disclosure is not limited thereto.

As utilized herein, a germanium (Ge) group may include an alkyl germanium group and an aryl germanium group. The germanium group may refer to a group in which a germanium atom is bonded to the defined alkyl group or aryl group. Examples of the germanium group may include a trimethyl germanium group, a triethyl germanium group, a t-butyl dimethyl germanium group, a vinyl dimethyl germanium group, a propyl dimethyl germanium group, a triphenyl germanium group, a diphenyl germanium group, a phenyl germanium group, and/or the like. However, one or more embodiments of the present disclosure is not limited thereto.

As utilized herein, a selenium (Se) group may include an alkyl selenium group and an aryl selenium group. The selenium group may refer to a group in which a selenium atom is bonded to the defined alkyl group or aryl group. Examples of the selenium group may include a methyl selenium group, an ethyl selenium group, a propyl selenium group, a pentyl selenium group, a hexyl selenium group, an octyl selenium group, a dodecyl selenium group, a cyclopentyl selenium group, a cyclohexyl selenium group, a phenyl selenium group, a naphthyl selenium group, and/or the like. However, one or more embodiments of the present disclosure is not limited thereto.

In the specification, the alkyl group among an alkylthio group, an alkylsulfoxy group, an alkylaryl group, an alkylamino group, an alkyl boron group, an alkyl silyl group, and an alkyl amine group, an alkyl germanium group, an alkyl selenium group is the same as the examples of the alkyl group described.

In the specification, the aryl group among an aryloxy group, an arylthio group, an arylsulfoxy group, an arylamino group, an arylboron group, an arylsilyl group, an arylamine group, an aryl germanium group, an aryl selenium group is the same as the examples of the aryl group described.

In the specification, a direct linkage may refer to a single bond. In the specification, “” and “” refer to a position to be connected.

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

Display Device

FIG. 1 is a plan view illustrating one or more embodiments of a display device DD. FIG. 2 is a cross-sectional view of the display device DD of the embodiment. FIG. 2 is a cross-sectional view illustrating a part taken along line I-I′ of FIG. 1.

The display device DD may include a display panel DP and an optical layer PP provided on the display panel DP. The display panel DP includes light emitting elements ED-1, ED-2, and ED-3. The display device DD may include a plurality of light emitting elements ED-1, ED-2, and ED-3. The optical layer PP may be provided on the display panel DP to control reflected light in the display panel DP due to external light. The optical layer PP may include, for example, a polarization layer or a color filter layer. In some embodiments, unlike the configuration illustrated in the drawing, the optical layer PP may not be provided from the display device DD of one or more embodiments.

A base substrate BL may be provided on the optical layer PP. The base substrate BL may be a member which provides a base surface on which the optical layer PP provided. The base substrate BL may be a glass substrate, a metal substrate, a plastic substrate, and/or the like. However, the embodiment of the present disclosure is not limited thereto, and the base substrate BL may be an inorganic layer, an organic layer, or a composite material layer. In some embodiments, unlike the configuration illustrated, in one or more embodiments, the base substrate BL may not be provided.

The display device DD according to one or more embodiments may further include a filling layer. The filling layer may be provided between a display element layer DP-ED and the base substrate BL. The filling layer may be an organic material layer. The filling layer may include at least one of an acrylic-based resin, a silicone-based resin, or an epoxy-based resin (e.g., at least one selected from among an acrylic-based resin, a silicone-based resin, and an epoxy-based resin).

The display panel DP may include a base layer BS, a circuit layer DP-CL provided on the base layer BS, and the display element layer DP-ED. The display element layer DP-ED may include a pixel defining film PDL, the light emitting elements ED-1, ED-2, and ED-3 provided between portions of the pixel defining film PDL, and an encapsulation layer TFE provided on the light emitting elements ED-1, ED-2, and ED-3.

The base layer BS may be a member which provides a base surface on which the display element layer DP-ED is provided. The base layer BS may be a glass substrate, a metal substrate, a plastic substrate, and/or the like. However, the embodiment is not limited thereto, and the base layer BS may be an inorganic layer, an organic layer, or a composite material layer.

In one or more embodiments, the circuit layer DP-CL is provided on the base layer BS, and the circuit layer DP-CL may include a plurality of transistors. Each of the transistors may include a control electrode, an input electrode, and an output electrode. For example, the circuit layer DP-CL may include a switching transistor and a driving transistor for driving the light emitting elements ED-1, ED-2, and ED-3 of the display element layer DP-ED.

Each of the light emitting elements ED-1, ED-2, and ED-3 may have a structure of each light emitting elements ED of embodiments according to FIGS. 3 to 7, as described in more detail herein. Each of the light emitting elements ED-1, ED-2, and ED-3 may include a first electrode EL1, a hole transport region HTR, a layer selected from emission layers EML-R, EML-G, and EML-B, an electron transport region ETR, and a second electrode EL2.

FIG. 2 illustrates one or more embodiments in which the emission layers EML-R, EML-G, and EML-B of the light emitting elements ED-1, ED-2, and ED-3 are provided in openings OH defined in the pixel defining film PDL, and the hole transport region HTR, the electron transport region ETR, and the second electrode EL2 are provided as a common layer in the entire light emitting elements ED-1, ED-2, and ED-3. However, the embodiment of the present disclosure is not limited thereto, and unlike the configuration illustrated in FIG. 2, the hole transport region HTR and the electron transport region ETR in one or more embodiments may be provided by being patterned inside the openings OH defined in the pixel defining film PDL. For example, the hole transport region HTR, the emission layers EML-R, EML-G, and EML-B, and the electron transport region ETR of the light emitting elements ED-1, ED-2, and ED-3 in one or more embodiments may be provided by being patterned in an inkjet printing method.

The encapsulation layer TFE may cover the light emitting elements ED-1, ED-2 and ED-3. The encapsulation layer TFE may seal the display element layer DP-ED. The encapsulation layer TFE may be a thin film encapsulation layer. The encapsulation layer TFE may be formed by laminating one layer or a plurality of layers. The encapsulation layer TFE includes at least one insulation layer. The encapsulation layer TFE according to one or more embodiments may include at least one inorganic film (hereinafter, an encapsulation-inorganic film). The encapsulation layer TFE according to one or more embodiments may also include at least one organic film (hereinafter, an encapsulation-organic film) and at least one encapsulation-inorganic film.

The encapsulation-inorganic film protects the display element layer DP-ED from moisture and/or oxygen, and the encapsulation-organic film protects the display element layer DP-ED from foreign substances such as dust particles. The encapsulation-inorganic film may include silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, aluminum oxide, and/or the like, but the embodiment of the present disclosure is not particularly limited thereto. The encapsulation-organic film may include an acrylic-based compound, an epoxy-based compound, and/or the like. The encapsulation-organic film may include a photopolymerizable organic material, but the embodiment of the present disclosure is not particularly limited thereto.

The encapsulation layer TFE may be provided on the second electrode EL2 and may be provided filling the opening OH.

Referring to FIGS. 1 and 2, the display device DD may include one or more non-light emitting region(s) NPXA and also include light emitting regions PXA-R, PXA-G, and PXA-B. The light emitting regions PXA-R, PXA-G, and PXA-B may be regions in which lights generated by the respective light emitting elements ED-1, ED-2, and ED-3 are emitted. The light emitting regions PXA-R, PXA-G, and PXA-B may be spaced and/or apart from each other on a plane (e.g., in a plan view).

Each of the light emitting regions PXA-R, PXA-G, and PXA-B may be a region divided (defined) by the pixel defining film PDL. The non-light emitting areas NPXA may be areas between the adjacent light emitting areas PXA-R, PXA-G, and PXA-B, which correspond to the pixel defining film PDL. In some embodiments, in the specification, the light emitting regions PXA-R, PXA-G, and PXA-B may respectively correspond to pixels. The pixel defining film PDL may divide the light emitting elements ED-1, ED-2, and ED-3. The emission layers EML-R, EML-G, and EML-B of the light emitting elements ED-1, ED-2, and ED-3 may be provided in openings OH defined in the pixel defining film PDL and separated from each other.

The light emitting regions PXA-R, PXA-G, and PXA-B may be divided into a plurality of groups according to the color of light generated from the light emitting elements ED-1, ED-2, and ED-3. In the display device DD of one or more embodiments illustrated in FIGS. 1 and 2, three light emitting regions PXA-R, PXA-G, and PXA-B, which emit red light, green light, and blue light, respectively, are exemplarily illustrated. For example, the display device DD of one or more embodiments may include the red light emitting region PXA-R, the green light emitting region PXA-G, and the blue light emitting region PXA-B that are separated from each other.

In the display device DD according to one or more embodiments, the plurality of light emitting elements ED-1, ED-2 and ED-3 may be to emit (e.g., configured to emit) light beams having wavelengths different from each other. For example, in one or more embodiments, the display device DD may include a first light emitting element ED-1 that emits red light, a second light emitting element ED-2 that emits green light, and a third light emitting element ED-3 that emits blue light. For example, the red light emitting region PXA-R, the green light emitting region PXA-G, and the blue light emitting region PXA-B of the display device DD may correspond to the first light emitting element ED-1, the second light emitting element ED-2, and the third light emitting element ED-3, respectively.

However, the embodiment of the present disclosure is not limited thereto, and the first to third light emitting elements ED-1, ED-2, and ED-3 may be to emit (e.g., configured to emit) light beams in substantially the same wavelength range or at least one light emitting element may be to emit (e.g., configured to emit) a light beam in a wavelength range different from the others. For example, the first to third light emitting elements ED-1, ED-2, and ED-3 may all emit blue light.

The light emitting regions PXA-R, PXA-G, and PXA-B in the display device DD according to one or more embodiments may be arranged in a stripe form. Referring to FIG. 1, the plurality of red light emitting regions PXA-R may be arranged with each other along a second directional axis DR2, the plurality of green light emitting regions PXA-G may be arranged with each other along the second directional axis DR2, and the plurality of blue light emitting regions PXA-B each may be arranged along the second directional axis DR2. In some embodiments, the red light emitting region PXA-R, the green light emitting region PXA-G, and the blue light emitting region PXA-B may be alternately arranged with each other in this order along a first directional axis DR1.

FIGS. 1 and 2 illustrate that all the light emitting regions PXA-R, PXA-G, and PXA-B have similar area, but the embodiment of the present disclosure is not limited thereto. Thus, the light emitting regions PXA-R, PXA-G, and PXA-B may have different areas from each other according to the wavelength range of the emitted light. In this case, the areas of the light emitting regions PXA-R, PXA-G, and PXA-B may refer to areas when viewed on a plane defined by the first directional axis DR1 and the second directional axis DR2 (e.g., in a plan view).

In some embodiments, an arrangement form of the light emitting regions PXA-R, PXA-G, and PXA-B is not limited to the configuration illustrated in FIG. 1, and the order in which the red light emitting region PXA-R, the green light emitting region PXA-G, and the blue light emitting region PXA-B are arranged may be provided in one or more suitable combinations according to the characteristics of display quality required in the display device DD. For example, the arrangement form of the light emitting regions PXA-R, PXA-G, and PXA-B may be a pentile (PENTILE™) arrangement form or a diamond (Diamond Pixel™) arrangement form, (PENTILE™ and Diamond Pixel™ are registered trademarks owned by Samsung Display Co., Ltd.).

In some embodiments, the areas of the light emitting regions PXA-R, PXA-G, and PXA-B may be different from each other. For example, in one or more embodiments, the area of the green light emitting region PXA-G may be smaller than that of the blue light emitting region PXA-B, but the embodiment of the present disclosure is not limited thereto.

Hereinafter, FIGS. 3 to 7 are cross-sectional views schematically illustrating a light-emitting element according to one or more embodiments. A light-emitting element ED according to one or more embodiments may include a first electrode EL1, a hole transport region HTR, an emission layer EML, an electron transport region ETR, and a second electrode EL2, which are sequentially stacked.

FIG. 4, compared with FIG. 3, illustrates a cross-sectional view of the light-emitting element ED according to one or more embodiments, in which the hole transport region HTR includes a hole injection layer HIL and a hole transport layer HTL, and the electron transport region ETR includes an electron injection layer EIL and an electron transport layer ETL. In some embodiments, FIG. 5, compared with FIG. 3, illustrates a cross-sectional view of the light-emitting element ED according to one or more embodiments, in which the hole transport region HTR includes a hole injection layer HIL, a hole transport layer HTL, and an electron blocking layer EBL, and the electron transport region ETR includes an electron injection layer EIL, an electron transport layer ETL, and a hole blocking layer HBL. FIG. 6, compared with FIG. 3, illustrates a cross-sectional view of the light-emitting element ED according to one or more embodiments, in which the hole transport region HTR includes a hole injection layer HIL, a hole transport layer HTL, and a light-emitting auxiliary layer EAL, and the electron transport region ETR includes an electron injection layer EIL, an electron transport layer ETL, and a hole blocking layer HBL. FIG. 7, compared with FIG. 4, illustrates a cross-sectional view of the light-emitting element ED according to one or more embodiments including a capping layer CPL provided on the second electrode EL2.

The first electrode EL1 has conductivity (e.g., is a conductor). The first electrode EL1 may be formed of a metal material, a metal alloy, or a conductive compound. The first electrode EL1 may be an anode or a cathode. However, the embodiment of the present disclosure is not limited thereto. In some embodiments, the first electrode EL1 may be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a transflective electrode, or a reflective electrode. The first electrode EL1 may include at least one selected from among Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, and Zn, a compound of two or more selected from among these, a mixture of two or more selected from among these, and/or an oxide thereof.

When the first electrode EL1 is the transmissive electrode, the first electrode EL1 may include a transparent metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium tin zinc oxide (ITZO). When the first electrode EL1 is the transflective electrode or the reflective electrode, the first electrode EL1 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF/Ca (a stacked structure of LiF and Ca), LiF/Al (a stacked structure of LiF and Al), Mo, Ti, W, a compound or mixture thereof (e.g., a mixture of Ag and Mg). In some embodiments, the first electrode EL1 may have a multilayer structure including a reflective film or a transflective film formed of the described materials, and a transparent conductive film formed of ITO, IZO, ZnO, ITZO, and/or the like. For example, the first electrode EL1 may have a three-layer structure of ITO/Ag/ITO, but the embodiment of the present disclosure is not limited thereto. In some embodiments, the embodiment of the present disclosure is not limited thereto, and the first electrode EL1 may include the described metal materials, combinations of at least two metal materials of the described metal materials, oxides of the described metal materials, and/or the like. The thickness of the first electrode EL1 may be from about 700 angstrom (A) to about 10,000 Å. For example, the thickness of the first electrode EL1 may be from about 1,000 Å to about 3,000 Å.

The hole transport region HTR is provided on the first electrode EL1. The hole transport region HTR may include at least one of a hole injection layer HIL, a hole transport layer HTL, a light-emitting auxiliary layer EAL, or an electron blocking layer EBL. The thickness of the hole transport region HTR may be, for example, from about 50 Å to about 15,000 Å. The light-emitting auxiliary layer EAL may also be referred to as a buffer layer.

The hole transport region HTR may have a single layer formed of a single material, a single layer formed of a plurality of different materials, or a multilayer structure including a plurality of layers formed of a plurality of different materials.

For example, the hole transport region HTR may have a single layer structure of the hole injection layer HIL or the hole transport layer HTL, or may have a single layer structure formed of a hole injection material and a hole transport material. In some embodiments, the hole transport region HTR may have a single layer structure formed of a plurality of different materials, or a structure in which a hole injection layer HIL/hole transport layer HTL, a hole injection layer HIL/hole transport layer HTL/light-emitting auxiliary layer EAL, a hole injection layer HIL/light-emitting auxiliary layer EAL, a hole transport layer HTL/light-emitting auxiliary layer EAL, or a hole injection layer HIL/hole transport layer HTL/electron blocking layer EBL are stacked in order from the first electrode EL1, but the embodiment of the present disclosure is not limited thereto.

The hole transport region HTR may be formed utilizing one or more suitable methods such as a vacuum deposition method, a spin coating method, a cast method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, and/or a laser induced thermal imaging (LITI) method.

The hole transport region HTR may include a compound represented by Formula H-1:

In Formula H-1, L₁ and L₂ may each independently be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms. a and b may each independently be an integer of 0 to 10. In some embodiments, when a or b is an integer of 2 or greater, a plurality of L₁'s and L₂'s may each independently be a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms.

In Formula H-1, Ar and Ar₂ may each independently be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. In some embodiments, in Formula H-1, Ar₃ may be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.

The compound represented by Formula H-1 may be a monoamine compound. In some embodiments, the compound represented by Formula H-1 may be a diamine compound in which at least one among Ar₁ to Ar₃ includes the amine group as a substituent. In some embodiments, the compound represented by Formula H-1 may be a carbazole-based compound including a substituted or unsubstituted carbazole group in at least one of Ar₁ or Ar₂, or a fluorene-based compound including a substituted or unsubstituted fluorene group in at least one of Ar₁ or Ar₂.

The compound represented by Formula H-1 may be represented by any one selected from among the compounds in Compound Group H. However, the compounds listed in Compound Group H are examples, and the compounds represented by Formula H-1 are not limited to those represented by Compound Group H:

The hole transport region HTR may include at least one selected from among a phthalocyanine compound such as copper phthalocyanine; N¹,N^1′-([1,1′-biphenyl]-4,4′-diyl)bis(N¹-phenyl-N⁴,N⁴-di-m-tolylbenzene-1,4-diamine) (DNTPD), 4,4′,4″-[tris(3-methylphenyl)phenylamino] triphenylamine (m-MTDATA), 4,4′,4″-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4′,4″-tris[N(2-naphthyl)-N-phenylamino]-triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB), triphenylamine-containing polyetherketone (TPAPEK), 4-isopropyl-4′-methyldiphenyliodonium [tetrakis(pentafluorophenyl)borate], dipyrazino[2,3-f: 2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HATCN), and/or the like.

The hole transport region HTR may include at least one selected from among a carbazole-based derivative such as N-phenyl carbazole or polyvinyl carbazole, a fluorene-based derivative, a triphenylamine-based derivative such as N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine (TPD) or 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB), 4,4′-cyclohexylidene bis[N,N-bis(4-methylphenyl]benzenamine](TAPC), 4,4′-bis[N,N′-(3-tolyl)amino]-3,3′-dimethylbiphenyl (HMTPD), 1,3-bis(N-carbazolyl)benzene (mCP), and/or the like.

In some embodiments, the hole transport region HTR may include 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi), 9-phenyl-9H-3,9′-bicarbazole (CCP), 1,3-bis(1,8-dimethyl-9H-carbazol-9-yl)benzene (mDCP), and/or the like.

The hole transport region HTR may include the described compounds of the hole transport region in at least one of a hole injection layer HIL, a hole transport layer HTL, a light-emitting auxiliary layer EAL or an electron blocking layer EBL.

The thickness of the hole transport region HTR may be from about 100 Å to about 10,000 Å, for example, from about 100 Å to about 5,000 Å. When the hole transport region HTR includes the hole injection layer HIL, the hole injection layer HIL may have, for example, a thickness of about 30 Å to about 1,000 Å. When the hole transport region HTR includes the hole transport layer HTL, the hole transport layer HTL may have a thickness of about 250 Å to about 1,000 Å. For example, when the hole transport region HTR includes the electron blocking layer EBL, the electron blocking layer EBL may have a thickness of about 10 Å to about 1,000 Å. When the thicknesses of the hole transport region HTR, the hole injection layer HIL, the hole transport layer HTL and the electron blocking layer EBL satisfy the described ranges, satisfactory hole transport properties may be achieved without a substantial increase in driving voltage.

The hole transport region HTR may further include a charge generating material to increase conductivity in addition to the described materials. The charge generating material may be dispersed uniformly or non-uniformly in the hole transport region HTR. The charge generating material may be, for example, a p-dopant. The p-dopant may include at least one of a halogenated metal compound, a quinone derivative, a metal oxide, or a cyano group-containing compound, but the embodiment of the present disclosure is not limited thereto. For example, the p-dopant may include a metal halide compound such as CuI or RbI, a quinone derivative such as tetracyanoquinodimethane (TCNQ) or 2,3,5,6-tetrafluoro-7,7′8,8-tetracyanoquinodimethane (F4-TCNQ), a metal oxide such as tungsten oxide or molybdenum oxide, a cyano group-containing compound such as dipyrazino[2,3-f:2′,3′-h] quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HATCN) or 4-[[2,3-bis[cyano-(4-cyano-2,3,5,6-tetrafluorophenyl)methylidene]cyclopropylidene]-cyanomethyl]-2,3,5,6-tetrafluorobenzonitrile (NDP9), and/or the like, but the embodiment of the present disclosure is not limited thereto.

As described, the hole transport region HTR may further include at least one among the light-emitting auxiliary layer EAL and the electron blocking layer EBL in addition to the hole injection layer HIL and the hole transport layer HTL. The light-emitting auxiliary layer EAL may compensate for a resonance distance according to a wavelength of light emitted from the light-emitting layer EML, and adjust a hole charge balance, thereby improving emission efficiency. In some embodiments, the light-emitting auxiliary layer EAL may also serve to prevent or reduce electrons from being injected to the hole transport region HTR. As a material included in the light-emitting auxiliary layer EAL, a material that may be included in the hole transport region HTR may be utilized. The electron blocking layer EBL may be a layer that serves to prevent or reduce electrons from being injected from the electron transport region ETR to the hole transport region HTR.

In the light-emitting element ED according to one or more embodiments, the light-emitting layer EML may include a first compound according to one or more embodiments. In some embodiments, the light-emitting layer EML according to one or more embodiments may further include at least one among second to fourth compounds. The second compound may include a fused ring of three rings containing a nitrogen atom as a ring-forming atom. The third compound may include a hexagonal cyclic group which includes at least one nitrogen atom as a ring-forming atom. The fourth compound may include an organometallic complex. The second to fourth compounds are described in more detail elsewhere herein.

As utilized herein, the first compound may be referred to as a fused polycyclic compound according to one or more embodiments. The fused polycyclic compound according to one or more embodiments may include, as a central structure, a fused ring of five rings containing two nitrogen atoms and one boron atom as ring-forming atoms. In the fused polycyclic compound according to one or more embodiments, a first substituent may be bonded at an ortho-position with respect to the boron atom, which is a ring-forming atom of the central structure.

For example, the first substituent may be a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted germanium group, a substituted or unsubstituted selenium group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms. The first substituent may not be (e.g., may exclude) a hydrogen atom or a deuterium atom. In the fused polycyclic compound according to one or more embodiments, the first substituent is bonded to a carbon atom at an ortho-position with a boron atom, which is a ring-forming atom of a central structure, and thus a reverse inter system crossing (RISC) speed may be improved, and lifespan of the light-emitting element ED according to one or more embodiments may be improved. In some embodiments, a light-emitting element ED according to one or more embodiments including the fused polycyclic compound according to one or more embodiments may exhibit excellent or suitable light efficiency.

The light-emitting element ED according to one or more embodiments may include the fused polycyclic compound according to one or more embodiments. The fused polycyclic compound according to one or more embodiments may be represented by Formula 1.

In Formula 1, at least one selected from among X₁ and X₂ may be a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted germanium (Ge) group, a substituted or unsubstituted selenium (Se) group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms. The remaining (e.g., rest among) X₁ and X₂ may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted germanium group, a substituted or unsubstituted selenium group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms.

At least one selected from among X₁ and X₂ may not be (e.g., may exclude) a hydrogen atom, or a deuterium atom. X₁ and X₂ may be substituents that are bonded to a carbon atom at an ortho-position with a boron atom, which is a ring-forming atom. At least one selected from among X₁ and X₂ may correspond to the described first substituent.

At least one selected from among X₁ and X₂ may be a halogen atom, a cyano group, a substituted or unsubstituted diphenylamine group, a substituted or unsubstituted methoxy group, a substituted or unsubstituted phenol group, a substituted or unsubstituted methylthio group, a substituted or unsubstituted germanium group, a substituted or unsubstituted selenium group, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, a substituted or unsubstituted isopropyl group, a substituted or unsubstituted n-propyl group, a substituted or unsubstituted i-butyl group, a substituted or unsubstituted s-butyl group, a substituted or unsubstituted t-pentyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrene group, a substituted or unsubstituted anthracene group, a substituted or unsubstituted thiophene group, a substituted or unsubstituted fluorene group, a substituted or unsubstituted pyridine group, a substituted or unsubstituted carbazole group, a substituted or unsubstituted dibenzofuran group, a substituted or unsubstituted dibenzothiophene group, or a substituted or unsubstituted dibenzoselenophene group.

At least one selected from among X₁ and X₂ may be a halogen atom or a cyano group, or be represented by any one selected from among X-1 to X-41. X-12 represents a methoxy group, and X-13 represents a methyl thio group. X-14 represents a methyl selenium group, and X-15 represents a phenol group. In X-2 and X-33, D may be a deuterium atom.

In Formula 1, Y₁ to Y₈ may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms. For example, Y₁ to Y₈ may all be deuterium atoms. In some embodiments, any one selected from among Y₁ to Y₈ may be a cyano group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbazole group, and the rest may be a deuterium atom.

In Formula 1, R₁ to R₅, R_b1 to R₄, and R_c1 to R_c6 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms. For example, R₁, R₄ and R₅ may be a deuterium atom.

R₂ may be a deuterium atom, a cyano group, an unsubstituted phenyl group, or a phenyl group substituted with a t-butyl group. R₃ may be a substituted or unsubstituted methyl group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted carbazole group, or a substituted or unsubstituted dibenzofuran group. For example, R₃ may be an unsubstituted methyl group, an unsubstituted t-butyl group, an unsubstituted phenyl group, an unsubstituted carbazole group, or an unsubstituted dibenzofuran group.

R_c1 and R_c4 may each independently be a hydrogen atom, or a substituted or unsubstituted t-butyl group. R_Cs and R_Ce may each independently be a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group. R_c2 and R_c5 may each independently be a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group. For example, R_c2 and R_c5 may each independently be a hydrogen atom, an unsubstituted t-butyl group, or an unsubstituted phenyl group.

n1 to n4 may each independently be an integer of 0 to 5. When n1 is an integer of 2 or more, a plurality of R_b1s may be the same, or at least one thereof may be different from the others. A case where n1 is 0 may be the same as a case where n1 is 5 and five R_b1s are all hydrogen atoms. When n2 is an integer of 2 or more, a plurality of R_b2s may be the same, or at least one thereof may be different from the others. A case where n2 is 0 may be the same as a case where n2 is 5 and five R_b2s are all hydrogen atoms. When n3 is an integer of 2 or more, a plurality of R_b3s may be the same, or at least one thereof may be different from the others. A case where n3 is 0 may be the same as a case where n3 is 5 and five R_b3s are all hydrogen atoms. When n4 is an integer of 2 or more, a plurality of R_b4s may be the same, or at least one thereof may be different from the others. A case where n4 is 0 may be the same as a case where n4 is 5 and five R_b4s are all hydrogen atoms.

R_a may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or be represented by Formula 2. Formula 2 represents a substituted or unsubstituted carbazole group, and is a site where a nitrogen atom, which is a ring-forming atom of the carbazole group, is bonded to Formula 1.

In Formula 2, Y₁₁ to Y₁₈ may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms. For example, Y₁₁ to Y₁₈ may all be deuterium atoms. In some embodiments, at least one selected from among Y₁₁ to Y₁₈ may be a cyano group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbazole group, and the rest may be a deuterium atom.

In Formula 1, a cyclic group including Y₁ to Y₈ may be a substituted or unsubstituted carbazole group. In Formula 1, R_a may be a substituted or unsubstituted carbazole group represented by Formula 2. Therefore, the fused polycyclic compound according to one or more embodiments may include at least one substituted or unsubstituted carbazole group bonded at a para-position with respect to a boron atom, which is a ring-forming atom, in the fused ring of five rings which is a central structure.

In some embodiments, the fused polycyclic compound according to one or more embodiments may include a terphenyl group directly bonded to each of two nitrogen atoms, which are ring-forming atoms, in the fused ring of five rings which is a central structure. The terphenyl group may be substituted or unsubstituted, and include R_b1 to R_b4, and R_c1 to R_c6 as substituents.

In one or more embodiments, Formula 1 may be represented by Formulas 1-1 or 1-2. Formula 1-1 shows a case where, in Formula 1, R_a is represented by Formula 2. Formula 1-2 shows a case where, in Formula 1, R_a is unrepresented by Formula 2.

In Formulas 1-1 and 1-2, descriptions of X₁, X₂, Y₁ to Y₈, Y₁₁ to Y₁₈, R₁ to R₅, R_b1 to R_b4, R_c1 to R_c6, and n1 to n4 in Formula 1 may be similarly applied. In Formula 1-2, R_a1 may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 60 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms. In Formula 1-2, R_a1 may be a deuterium atom, or be represented by any one selected from among A-1 to A-4.

A-1 represents an unsubstituted t-butyl group, and A-2 represents an unsubstituted phenyl group. A-3 represents a phenyl group substituted with a t-butyl group, and A-4 represents an unsubstituted diphenylamine group.

In one or more embodiments, Formula 1-1 may be represented by Formulas 1-1A or 1-1B. Formula 1-1A represents a case where, in Formula 1-1, Y₁ to Y₈, Y₁₁ to Y₁₈ are deuterium atoms. Formula 1-1B represents a case where, in Formula 1-1, Y₁, Y₂, Y₄ to Y₈, Y₁₁, Y₁₂, and Y₁₄ to Y₁₈ are deuterium atoms.

In Formulas 1-1A and 1-1B, D may be a deuterium atom, and descriptions of X₁, X₂, R₁ to R₅, R_b1 to R₄, R_c1 to R_c6, and n1 to n4 in Formula 1-1 may be similarly applied. In Formula 1-1B, Y_3a to Y_13a may each independently be a cyano group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbazole group.

For example, Y_3a and Y_13a may each independently be a cyano group, an unsubstituted t-butyl group, an unsubstituted phenyl group, or an unsubstituted carbazole group. When Y_3a and Y_13a are unsubstituted carbazole groups, a nitrogen atom, which is a ring-forming atom of the carbazole group, may be a bonding site.

The fused polycyclic compound according to one or more embodiments may include a deuterium atom, or include at least one deuterium atom as a substituent. In the fused polycyclic compound according to one or more embodiments, a deuterium atom may be directly bonded to the fused ring of five rings, or a substituent substituted with a deuterium atom may be bonded to the fused ring of five rings.

The fused polycyclic compound according to one or more embodiments may be represented by at least one selected from among compounds in Compound Group 1. The light-emitting element ED according to one or more embodiments may include at least one selected from among compounds in Compound Group 1. D may be a deuterium atom in Compound Group 1.

An emission layer EML may include the fused polycyclic compound according to one or more embodiments as a dopant. The fused polycyclic compound according to one or more embodiments may be a thermally activated delayed fluorescence (TADF) material. The fused polycyclic compound according to one or more embodiments may be a multiple resonance (MR)-type or kind TADF material. The fused polycyclic compound according to one or more embodiments may have E_ST, which is an absolute value of a difference in energy levels between a singlet (S1) state and a triplet (T1) state, of about 0.2 electron volt (eV) or less. Because the fused polycyclic compound according to one or more embodiments has a small difference in energy levels of about 0.2 eV or less, a triplet exciton may be converted to a singlet exciton due to the RISC mechanism, thus making it possible to cause light to be emitted. Because the fused polycyclic compound according to one or more embodiments has a relatively small difference in energy levels, the RISC may rapidly occur and material deterioration due to excitons may be reduced, thereby exhibiting excellent or suitable material stability.

According to the EI-sayed rule, as a spin-orbit coupling (SOC) constant between the singlet state and the triplet state in blue dopants gets closer to 0 (zero), it is less likely that a direct transition from the singlet state to the triplet state occurs. As a result, in typical blue dopants, light is emitted through a complex inter system crossing mechanism that involves the high-order triplet state (Tn).

The fused polycyclic compound according to one or more embodiments may include, as a central structure, a fused ring of five rings, which contains two nitrogen atoms and one boron atom as ring-forming atoms, and a first substituent bonded to a carbon atom at an ortho-position with respect to the boron atom. In Formula 1, at least one selected from among X₁ and X₂ may be the first substituent. The number of the first substituent may be one or two, and the first substituent may not be (e.g., may exclude) a hydrogen atom or a deuterium atom.

The fused polycyclic compound according to one or more embodiments introduces the first substituent at the ortho-position with respect to a boron atom in the fused ring of five rings, which is a central structure, thereby causing distortion of the central structure, which is a light-emitting center, and mixing of a local excited (LE) state and a charge transfer (CT) state. Therefore, an orbital distribution between the singlet (S1) state and the triplet (T1) state may be changed. In the fused polycyclic compound according to one or more embodiments, the orbital distribution between the singlet (S1) state and the triplet (T1) state is changed, and thus the SOC constant between the singlet (S1) state and the triplet (T1) state is improved, thereby making it possible to increase the RISC and to contribute to improving the light efficiency and lifespan of the light-emitting element ED. In some embodiments, the fused polycyclic compound according to one or more embodiments has a structure that (e.g., selectively) protects an ortho-position, with respect to a boron atom, which is the weakest spot in a dopant that contains boron as a ring-forming atom, and thus the light-emitting element ED including the fused polycyclic compound according to one or more embodiments may exhibit long-lifespan characteristics.

The fused polycyclic compound according to one or more embodiments may be to emit blue light that has an emission center wavelength in the range of about 430 nanometer (nm) to about 490 nm. The light-emitting element ED including the fused polycyclic compound according to one or more embodiments may be to emit light that has an emission center wavelength in the range of about 430 nm to about 490 nm. The light-emitting element ED including the fused polycyclic compound according to one or more embodiments may be to emit blue light. For example, the third light-emitting element ED-3 (see FIG. 2) which emits blue light may include the fused polycyclic compound according to one or more embodiments.

In one or more embodiments, the light-emitting layer EML may include the fused polycyclic compound according to one or more embodiments, and further include at least one selected from among second to fourth compounds. In one or more embodiments, the light-emitting layer EML may include the second compound represented by Formula HT-1. For example, the second compound may be utilized as a hole transporting host material of the light-emitting layer EML.

In Formula HT-1, A₁ to A₈ may each independently be N or CR₅₁. For example, each (e.g., all) of A₁ to A₈ may be CR₅₁. In some embodiments, any one of A₁ to A₈ may be N, and the rest (e.g., remaining A₁ to A₈) may be CR₅₁.

In Formula HT-1, L1 may be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms. For example, L1 may be a direct linkage, a substituted or unsubstituted phenylene group, a substituted or unsubstituted divalent biphenyl group, a substituted or unsubstituted divalent carbazole group, and/or the like, but the embodiment of the present disclosure is not limited thereto.

In Formula HT-1, Y₈ may be a direct linkage, CR₅₂R₅₃, or SiR₅₄R₅₅. For example, it may refer to that the two benzene rings linked to the nitrogen atom in Formula HT-1 are linked via a direct linkage,

In Formula HT-1, when Y₈ is a direct linkage, the second compound represented by Formula HT-1 may include a carbazole moiety.

In Formula HT-1, Ar₁ may be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, Ar₁ may be a substituted or unsubstituted carbazole group, a substituted or unsubstituted dibenzofuran group, a substituted or unsubstituted dibenzothiophene group, a substituted or unsubstituted biphenyl group, and/or the like, but the embodiment of the present disclosure is not limited thereto.

In Formula HT-1, R₅₁ to R₅₅ may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted thio group, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms. In some embodiments, each of R₅₁ to R₅₅ may be bonded to an adjacent group to form a ring. For example, R₅₁ to R₅₅ may each independently be a hydrogen atom or a deuterium atom. R₅₁ to R₅₅ may each independently be an unsubstituted methyl group or an unsubstituted phenyl group.

In one or more embodiments, the second compound represented by Formula HT-1 may be represented by any one selected from among the compounds represented by Compound Group 2. The emission layer EML may include at least one selected from among the compounds represented by Compound Group 2 as a hole transporting host material.

In embodiment compounds presented in Compound Group 2, “D” may refer to a deuterium atom, and “Ph” may refer to a substituted or unsubstituted phenyl group. For example, in embodiment compounds presented in Compound Group 2, “Ph” may refer to an unsubstituted phenyl group.

In one or more embodiments, the light-emitting layer EML may include the third compound represented by Formula ET-1. For example, the third compound may be utilized as an electron transporting host material of the light-emitting layer EML.

In Formula ET-1, at least one selected from among X₁₁ to X₁₃ may be N, and the rest (e.g., each of the remaining X₁ to X₃) may be CR₅₆. For example, any one selected from among X₁₁ to X₁₃ may be N, and the rest (e.g., each of the remaining X₁ to X₃) two may each independently be CR₅₆. In this case, the third compound represented by Formula ET-1 may include a pyridine moiety. In some embodiments, two among X₁₁ to X₁₃ may be N, and the one remaining X₁ to X₃ may be CR₅₆. In this case, the third compound represented by Formula ET-1 may include a pyrimidine moiety. In some embodiments, X₁₁ to X₁₃ may all be N. In this case, the third compound represented by Formula ET-1 may include a triazine moiety.

In Formula ET-1, R₅₆ may be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms.

In Formula ET-1, b1 to b3 may each independently be an integer of 0 to 10.

In Formula ET-1, Ar₂ to Ar₄ may each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. For example, Ar₂ to Ar₄ may be a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbazole group.

In Formula ET-1, L2 to L4 may each independently be a direct linkage, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms. In some embodiments, when b1 to b3 are each an integer of 2 or more, L2 to L4 may each independently be a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring-forming carbon atoms. A case where b1 is 0 may be the same as a case where b1 is 1 and L2 is a direct linkage. A case where b2 is 0 may be the same as a case where b2 is 1 and L₃ is a direct linkage. A case where b3 is 0 may be the same as a case where b3 is 1 and L4 is a direct linkage.

In one or more embodiments, the third compound may be represented by any one selected from among compounds in Compound Group 3. The light-emitting element ED according to one or more embodiments may include any one selected from among the compounds in Compound Group 3.

In (e.g., specific) example compounds presented in Compound Group 3, D refers to a deuterium atom, and Ph refers to an unsubstituted phenyl group.

The emission layer EML may include the second compound and the third compound, and the second compound and the third compound may form an exciplex. In the emission layer EML, an exciplex may be formed by the hole transport host and the electron transport host. In this case, a triplet energy of the exciplex formed by the hole transporting host and the electron transporting host may correspond to the difference between a lowest unoccupied molecular orbital (LUMO) energy level of the electron transporting host and a highest occupied molecular orbital (HOMO) energy level of the hole transporting host.

For example, the absolute value of the triplet energy (T1) of the exciplex formed by the hole transporting host and the electron transporting host may be about 2.4 eV to about 3.0 eV. In some embodiments, the triplet energy of the exciplex may be a value smaller than an energy gap of each host material. The exciplex may have a triplet energy of about 3.0 eV or less that is an energy gap between the hole transporting host and the electron transporting host.

In one or more embodiments, the emission layer EML may include a fourth compound in addition to the first compound to the third compound as described. The fourth compound may be utilized as a phosphorescent sensitizer of the emission layer EML. The energy may be transferred from the fourth compound to the first compound, thereby emitting light.

For example, the emission layer EML may include, as the fourth compound, an organometallic complex containing platinum (Pt) as a central metal atom and ligands linked to the central metal atom. The emission layer EML in the light emitting elements ED of one or more embodiments may include, as the fourth compound, a compound represented by Formula D-1:

Claims

1. A light-emitting element comprising: a first electrode;a second electrode on the first electrode; andan emission layer between the first electrode and the second electrode and comprising a first compound represented by Formula 1:

2. The light-emitting element of claim 1, wherein the emission layer further comprises at least one of a second compound represented by Formula HT-1, a third compound represented by Formula ET-1, or a fourth compound represented by Formula D-1:

3. The light-emitting element of claim 1, wherein Formula 1 is represented by one of Formula 1-1 or Formula 1-2:

4. The light-emitting element of claim 3, wherein Formula 1-1 is represented by one of Formula 1-1A or Formula 1-1B:

5. The light-emitting element of claim 3, wherein in Formula 1-2, Ra1 is a deuterium atom, or represented by at least one selected from among A-1 to A-4:

6. The light-emitting element of claim 1, wherein in Formula 1, at least one of X1 or X2 is a halogen atom or a cyano group, or is represented by at least one selected from among X-1 to X-41:

7. The light-emitting element of claim 1, wherein in Formula 1, at least one of X1 or X2 is a halogen atom, a cyano group, a substituted or unsubstituted diphenylamine group, a substituted or unsubstituted methoxy group, a substituted or unsubstituted phenol group, a substituted or unsubstituted methylthio group, a substituted or unsubstituted germanium group, a substituted or unsubstituted selenium group, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, a substituted or unsubstituted isopropyl group, a substituted or unsubstituted n-propyl group, a substituted or unsubstituted i-butyl group, a substituted or unsubstituted s-butyl group, a substituted or unsubstituted t-pentyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrene group, a substituted or unsubstituted anthracene group, a substituted or unsubstituted thiophene group, a substituted or unsubstituted fluorene group, a substituted or unsubstituted pyridine group, a substituted or unsubstituted carbazole group, a substituted or unsubstituted dibenzofuran group, a substituted or unsubstituted dibenzothiophene group, or a substituted or unsubstituted dibenzoselenophene group.

8. The light-emitting element of claim 1, wherein, in Formula 1, R3 is a substituted or unsubstituted methyl group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted carbazole group, or a substituted or unsubstituted dibenzofuran group.

9. The light-emitting element of claim 1, wherein, in Formula 1, Rc2 and Rc5 are each independently a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.

10. The light-emitting element of claim 1, wherein the first compound is represented by at least one selected from among compounds in Compound Group 1:

11. A fused polycyclic compound represented by Formula 1:

12. The fused polycyclic compound of claim 11, wherein Formula 1 is represented by one of Formula 1-1 or Formula 1-2:

13. The fused polycyclic compound of claim 12, wherein Formula 1-1 is represented by one of Formula 1-1A or Formula 1-1B:

14. The fused polycyclic compound of claim 12, wherein, in Formula 1-2, Ra1 is a deuterium atom or is represented by at least one selected from among A-1 to A-4:

15. The fused polycyclic compound of claim 11, wherein, in Formula 1, at least one of X1 or X2 is a halogen atom or a cyano group, or is represented by at least one selected from among X-1 to X-41:

16. The fused polycyclic compound of claim 11, wherein in Formula 1, at least one of X1 or X2 is a halogen atom, a cyano group, a substituted or unsubstituted diphenylamine group, a substituted or unsubstituted methoxy group, a substituted or unsubstituted phenol group, a substituted or unsubstituted methylthio group, a substituted or unsubstituted germanium group, a substituted or unsubstituted selenium group, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, a substituted or unsubstituted isopropyl group, a substituted or unsubstituted n-propyl group, a substituted or unsubstituted i-butyl group, a substituted or unsubstituted s-butyl group, a substituted or unsubstituted t-pentyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrene group, a substituted or unsubstituted anthracene group, a substituted or unsubstituted thiophene group, a substituted or unsubstituted fluorene group, a substituted or unsubstituted pyridine group, a substituted or unsubstituted carbazole group, a substituted or unsubstituted dibenzofuran group, a substituted or unsubstituted dibenzothiophene group, or a substituted or unsubstituted dibenzoselenophene group.

17. The fused polycyclic compound of claim 11, wherein, in Formula 1, R3 is a substituted or unsubstituted methyl group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted carbazole group, or a substituted or unsubstituted dibenzofuran group.

18. The fused polycyclic compound of claim 11, wherein, in Formula 1, Rc2 and Rc5 are each independently a hydrogen atom, a substituted or unsubstituted t-butyl group, or a substituted or unsubstituted phenyl group.

19. The fused polycyclic compound of claim 11, wherein Formula 1 is represented by at least one selected from among compounds in Compound Group 1:

20. The fused polycyclic compound of claim 11, wherein a spin-orbit coupling (SOC) constant of the compound is about 0.3 cm−1 or more.

21. A display device comprising: a base layer;a circuit layer on the base layer; anda display element layer on the circuit layer and comprising a light-emitting element,wherein the light-emitting element comprises a first electrode, a second electrode on the first electrode, and an emission layer between the first electrode and the second electrode and comprising a fused polycyclic compound represented by Formula 1:

22. The display device of claim 21, wherein the light-emitting element comprises a first light-emitting element configured to emit red light, a second light-emitting element configured to emit green light, and a third light-emitting element configured to emit blue light, andthe third light-emitting element comprises the fused polycyclic compound.

23. The display device of claim 21, wherein the light-emitting element is configured to emit blue light.

24. The display device of claim 21, further comprising: a light control layer on the display element layer and comprising quantum dots.