Light-emitting element, ink composition, and display device including light-emitting element

Abstract

The invention relates to a light-emitting element, an ink composition, and a display device including the light-emitting element. The light emitting element includes a first electrode, a hole transport region on the first electrode, an emission layer on the hole transport region, an electron transport region on the emission layer, and a second electrode on the electron transport region, the electron transport region including a nanoparticle including a nanoparticle core including a core compound represented by Formula 1 and a ligand, and the ligand is bonded to the surface of the nanoparticle core and is represented by Formula 2 or Formula 3. Formula 1AxOy 2 # imgabs 0 # and formula 3 # imgabs 1 #

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0107220 filed in the Korean Intellectual Property Office on August 16, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Embodiments of the present disclosure herein relate to a light-emitting element, an ink composition, and a display device including the light-emitting element, and, for example, to a light-emitting element having improved emission efficiency and element life (also referred to as “lifetime”) and a display device including the light-emitting element. Background Art

[0004] Recently, development of organic electroluminescent displays as image displays for image display devices is being actively carried out. The organic electroluminescent display is different from a liquid crystal display and is a so-called self-luminous display device in which holes and electrons injected from a first electrode and a second electrode are recombined in an emission layer so that a light-emitting material including an organic compound in the emission layer emits light to achieve display.

[0005] In applying an organic electroluminescent element to a display device, increases in emission efficiency and lifetime are useful, and development of materials for light-emitting elements that stably achieve desired characteristics is being continuously conducted.

[0006] In order to provide a light-emitting element having high emission efficiency and long lifetime, development of a material for an electron transport region having excellent electron transport characteristics and stability is underway. Summary of the invention

[0007] An object of embodiments of the present disclosure is to provide a light emitting element having improved emission efficiency and element lifetime.

[0008] Another object of an embodiment of the present disclosure is to provide an ink composition capable of improving emission characteristics and element life of a light-emitting element.

[0009] Another object of an embodiment of the present disclosure is to provide a display device including a light emitting element having improved emission efficiency and element lifespan.

[0010] According to an embodiment of the present disclosure, a light-emitting element includes a first electrode, a hole transport region on the first electrode, an emission layer on the hole transport region, an electron transport region on the emission layer, and a second electrode on the electron transport region, wherein the electron transport region includes nanoparticles including a nanoparticle core and a ligand, the nanoparticle core includes a core compound represented by Formula 1, and the ligand is bonded to the surface of the nanoparticle core and represented by Formula 2 or Formula 3.

[0011] Formula 1

[0012] A x O y

[0013] Formula 2

[0014]

[0015] Formula 3

[0016]

[0017] In Formula 1, A is Zn or Sn, and x and y are each independently an integer selected from 1 to 5, in Formula 2, M is one of Li, Na, K, Rb, Cs, Be, Ca, Sr and Ba, R 1 is a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms, a is an integer selected from 0 to 3, and "-*" and Each is a position connected to the nanoparticle core, and in Formula 3, R 2 It is a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, M is the same as M defined in Formula 2, b is an integer selected from 0 to 3, and "—*" is the position connected to the nanoparticle core.

[0018] In an embodiment, the electron transport region may include an electron transport layer on the emission layer and an electron injection layer on the electron transport layer, and the electron transport layer may include nanoparticles.

[0019] In embodiments, the nanoparticle core may be doped with a metal element.

[0020] In an embodiment, the metal element may be at least one of Zn, Mg, Li, Na, Ni, and Cu.

[0021] In an embodiment, the emissive layer may include quantum dots.

[0022] In an embodiment, in Formula 1, x may be 1, and y may be 2.

[0023] In an embodiment, in Formula 1, A may be Sn, and in Formula 2 and Formula 3, M may be Ca.

[0024] In an embodiment, if the ligand is represented by Formula 2, then R1 may be a substituted or unsubstituted alkyl group of 1 to 5 carbon atoms, and if the ligand is represented by Formula 3, then R 2 The alkyl group may be a substituted or unsubstituted alkyl group of 1 to 5 carbon atoms.

[0025] In an embodiment, if the ligand is represented by Formula 2, then R 1 may be a substituted or unsubstituted alkyl group of 6 to 20 carbon atoms, and if the ligand is represented by Formula 3, then R 2 The alkyl group may be a substituted or unsubstituted alkyl group having 6 to 20 carbon atoms.

[0026] The ink composition according to an embodiment of the present disclosure includes: a nanoparticle core including a core compound represented by Formula 1; a primary ligand represented by Formula 4; and a solvent in which the nanoparticle core and the primary ligand are dispersed.

[0027] Formula 1

[0028] A x O y

[0029] Formula 4

[0030]

[0031] In Formula 1, A is Zn or Sn, and x and y are each independently an integer selected from 1 to 5, in Formula 4, M is one of Li, Na, K, Rb, Cs, Be, Ca, Sr and Ba, R 3 and R 4 Each is independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, and c and d are each independently an integer selected from 0 to 3.

[0032] In an embodiment, in Formula 4, R 3 and R 4 Each may independently be a substituted or unsubstituted alkyl group of 1 to 5 carbon atoms.

[0033] In an embodiment, the solvent may include a water-soluble solvent.

[0034] In embodiments, the weight ratio of the nanoparticle core to the water-soluble solvent may be about 1% to about 10%.

[0035] In an embodiment, the water-soluble solvent may include a first solvent compound represented by Formula 5.

[0036] Formula 5

[0037]

[0038] In Formula 5, R 11 and R 12 are each independently a substituted or unsubstituted alkylene group of 1 to 4 carbon atoms, R 13 is a substituted or unsubstituted alkyl group of 1 to 4 carbon atoms, and t is 1 or 2.

[0039] In an embodiment, the first solvent compound may include at least one of diethylene glycol tert-butyl ether (DGtBE), tripropylene glycol monobutyl ether (TPGBE), and triethylene glycol monoisopropyl ether (TGIPE).

[0040] In an embodiment, in Formula 4, R 3 and R 4 Each may independently be a substituted or unsubstituted alkyl group having 6 to 20 carbon atoms.

[0041] In an embodiment, the solvent may include at least one of cyclohexylbenzene (CHB) and hexadecane.

[0042] A display device according to an embodiment of the present disclosure includes a substrate layer, a circuit layer on the substrate layer, and a display element layer on the circuit layer and including a light-emitting element, wherein the light-emitting element includes a first electrode, a second electrode on the first electrode, and an electron transport region between the first electrode and the second electrode, the electron transport region includes nanoparticles including nanoparticle cores and ligands, the nanoparticle cores include a core compound represented by Formula 1, and the ligands are bonded to the surface of the nanoparticle cores and represented by Formula 2 or Formula 3.

[0043] Formula 1

[0044] A x O y

[0045] Formula 2

[0046]

[0047] Formula 3

[0048]

[0049] In Formula 1, A is Zn or Sn, and x and y are each independently an integer selected from 1 to 5, in Formula 2, M is one of Li, Na, K, Rb, Cs, Be, Ca, Sr and Ba, R 1is a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms, a is an integer selected from 0 to 3, and "-*" and Each is a position connected to the nanoparticle core, and in Formula 3, R 2 is a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, M is the same as M defined in Formula 2, b is an integer selected from 0 to 3, and "-*" is the position connected to the nanoparticle core.

[0050] In an embodiment, the light emitting element may further include a hole transport region on the first electrode and an emission layer between the hole transport region and the electron transport region, and the emission layer may include quantum dots.

[0051] In an embodiment, the electron transport region may include an electron transport layer on the emission layer and an electron injection layer on the electron transport layer, and the electron transport layer may include nanoparticles. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The accompanying drawings are included to provide a further understanding of the subject matter of the present disclosure and are incorporated in and constitute a part of this specification. The accompanying drawings illustrate embodiments of the present disclosure and together with the description serve to explain the principles of the embodiments of the present disclosure. In the drawings:

[0053] Figure 1 is a perspective view showing a display device according to an embodiment;

[0054] Figure 2 To show along Figure 1 A cross-sectional view of a portion taken along line II' in FIG.

[0055] Figure 3 is a plan view showing a display device according to an embodiment;

[0056] Figure 4 To show along Figure 3 A cross-sectional view of a portion taken along line II-II';

[0057] Figure 5 is a cross-sectional view showing a light emitting element according to an embodiment;

[0058] Figure 6 is a diagram showing a portion of an ink composition according to an embodiment; and

[0059] Figure 7 and Figure 8 is a diagram showing a portion of a nanoparticle according to an embodiment. DETAILED DESCRIPTION

[0060] The subject matter of the present disclosure may have various modifications and may be implemented in different forms, and the example embodiments will be explained in more detail with reference to the accompanying drawings. However, the subject matter of the present disclosure may be implemented in different forms and should not be interpreted as being limited to the embodiments set forth herein. On the contrary, all modifications, equivalents, and alternatives included within the spirit and technical scope of the present disclosure should be included within the scope of the present disclosure.

[0061] In the description, when an element (or region, layer, portion, etc.) is referred to as being "on" another element (or region, layer, portion, etc.), "connected to" or "bonded to" another element (or region, layer, portion, etc.), it may be directly on / directly connected to / directly bonded to another element (or region, layer, portion, etc.), or an intervening third element may also be provided.

[0062] The same reference numerals refer to the same elements throughout the text. In the accompanying drawings, the proportions and sizes (e.g., thickness) of the elements may be exaggerated for effective explanation of the technical content. "And / or" may include one or more combinations that may define related elements.

[0063] It will be understood that although the terms "first", "second", etc. may be used in this article to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the present disclosure, a first element may be referred to as a second element. Similarly, a second element may be referred to as a first element. As used herein, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise.

[0064] In the embodiments, the terms "below", "beneath", "on", and "above" are used to explain the relationship of elements shown in the drawings. These terms are relative concepts and are explained based on the directions shown in the drawings, but the present disclosure is not limited thereto.

[0065] It will be further understood that when the terms “comprises” or “comprising” are used in this specification, it indicates the presence of the recited features, numbers, steps, operations, elements, parts or any combination thereof, but does not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, parts or any combination thereof.

[0066] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this article have the same meaning as those generally understood by those of ordinary skill in the art to which the present disclosure belongs. In the embodiments, it will be further understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant field and will not be interpreted in an ideal or overly formal sense, unless explicitly defined in this article.

[0067] In the description, the term "substituted or unsubstituted" corresponds to being substituted or unsubstituted by at least one substituent selected from the group consisting of: deuterium atoms, halogen atoms, cyano groups, nitro groups, amine groups, silyl groups, oxy groups, sulfenyl groups, sulfinyl groups, sulfonyl groups, carbonyl groups, boron groups, phosphine oxide groups, phosphine sulfide groups, alkyl groups, alkenyl groups, alkynyl groups, hydrocarbon ring groups, aryl groups, and heterocyclic groups. In an embodiment, each of the exemplified substituents may be substituted or unsubstituted. For example, biphenyl groups may be interpreted as aryl groups or phenyl groups substituted by phenyl groups.

[0068] In the description, the alkyl group may be a linear or branched type (eg, a linear or branched alkyl group). The carbon number of the alkyl group may be 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 methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, tert-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyldecyl, n- Undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, 2-ethyleicosyl, 2-butyleicosyl, 2-hexyleicosyl, 2-octyleicosyl, n-heonicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, n-triacontyl and the like without limitation.

[0069] In the description, the alkoxy group may include an alkyl group defined above combined with an oxygen atom. The alkoxy group may be a straight chain alkoxy group, a branched chain alkoxy group or a cycloalkoxy group. The carbon number of the alkoxy group is not specifically limited, but may be, for example, 1 to 30, 1 to 20, 1 to 10 or 1 to 5. Examples of alkoxy groups may include methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, octyloxy, nonyloxy, decyloxy, etc. However, embodiments of the present disclosure are not limited thereto.

[0070] In the description, the carbon number of the amine group is not particularly limited, but may be 1 to 30, 1 to 20, or 1 to 10. The amine group may include an alkylamine group and an arylamine group. Examples of the amine group include methylamine group, dimethylamine group, phenylamine group, diphenylamine group, naphthylamine group, 9-methyl-anthrylamine group, etc., without limitation.

[0071] In the specification, alkenyl refers to a hydrocarbon group including at least one carbon-carbon double bond in the middle or at the end of an alkyl group having 2 or more carbon atoms. The alkenyl group may be straight chain or branched. The number of carbon atoms in the alkenyl group is not specifically limited, but is 2 to 30, 2 to 20 or 2 to 10. Examples of alkenyl groups may include vinyl, 1-butenyl, 1-pentenyl, 1,3-butadienyl, styryl and / or styrylvinyl, etc., but embodiments of the present disclosure are not limited thereto.

[0072] In the specification, alkynyl refers to a hydrocarbon group including at least one carbon-carbon triple bond in the middle or at the end of an alkyl group having 2 or more carbon atoms. The alkynyl group may be straight chain 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 alkynyl groups may include ethynyl and / or propynyl, etc., but are not limited thereto.

[0073] 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 30 or 5 to 20 ring-forming carbon atoms.

[0074] In the specification, aryl refers to any functional group or substituent derived from an aromatic hydrocarbon ring. The aryl may be a monocyclic aryl or a polycyclic aryl. The number of ring-forming carbon atoms in the aryl may be 6 to 60, 6 to 50, 6 to 40, 6 to 30, 6 to 20 or 6 to 15. Examples of aryl may include phenyl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl, biphenyl, terphenyl, quaterphenyl, pentaphenyl, hexaphenyl, triphenylene, pyrenyl, benzofluoranthenyl and / or 1,2-triphenylenyl, etc., but embodiments of the present disclosure are not limited thereto.

[0075] 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 embodiments of the present disclosure are not limited thereto.

[0076]

[0077] Heterocyclic groups herein refer to any functional group or substituent derived from a ring containing at least one of B, O, N, P, Si, S and Se as a heteroatom. Heterocyclic groups include aliphatic heterocyclic groups and aromatic heterocyclic groups. Aromatic heterocyclic groups may be heteroaryl groups. Aliphatic heterocyclic groups and aromatic heterocyclic groups may be monocyclic or polycyclic.

[0078] In the specification, the heterocyclic group may contain at least one of B, O, N, P, Si, S and Se as a heteroatom. When the heterocyclic group contains two or more heteroatoms, the two or more heteroatoms may be the same 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 carbon atoms in the heterocyclic group may be 2 to 60, 2 to 50, 2 to 40, 2 to 30, 2 to 20 or 2 to 10.

[0079] In the specification, the aliphatic heterocyclic group may include at least one of B, O, N, P, Si, S and Se as a heteroatom. The number of ring-forming carbon atoms in the aliphatic heterocyclic group may be 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 pyrrolidinyl group, a piperidinyl group, a tetrahydrofuranyl group, a tetrahydrothienyl group, a thianyl group, a tetrahydropyranyl group and / or a 1,4-dioxanyl group, etc., but embodiments of the present disclosure are not limited thereto.

[0080] In the specification, the heteroaryl group may contain at least one of B, O, N, P, Si, S and Se as a heteroatom. When the heteroaryl group includes two or more heteroatoms, the two or more heteroatoms may be the same or different from each other. The heteroaryl group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group. The number of ring carbon atoms in the heteroaryl group may be 2 to 60, 2 to 50, 2 to 40, 2 to 30, 2 to 20 or 2 to 10. Examples of heteroaryl groups may include thienyl, furyl, pyrrolyl, imidazolyl, pyridyl, bipyridyl, pyrimidyl, triazine, triazolyl, acridinyl, pyridazinyl, pyrazinyl, quinolyl, quinazolinyl, quinoxalinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolyl, indolyl, carbazolyl, N-arylcarbazolyl, N-heteroarylcarbazolyl, N-alkylcarbazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothienyl, dibenzothienyl, thienothiphenyl, benzofuranyl, phenanthrolinyl, thiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, thiadiazolyl, phenothiazinyl, dibenzothirolyl and / or dibenzofuranyl, but embodiments of the present disclosure are not limited thereto.

[0081] In the specification, the description of the aryl group can be applied to the arylene group, except that the arylene group is a divalent group. The description of the heteroaryl group can be applied to the heteroarylene group, except that the heteroarylene group is a divalent group.

[0082] In the specification, silyl includes alkylsilyl and arylsilyl. The alkyl in the alkylsilyl may be linear, branched or cyclic. The number of carbon atoms in the alkylsilyl is not specifically limited, but may be, for example, 1 to 20 or 1 to 10. The number of carbon atoms in the arylsilyl is not specifically limited, but may be, for example, 6 to 30, 6 to 20 or 6 to 15. Examples of silyl may include trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl and / or phenylsilyl, etc., but embodiments of the present disclosure are not limited thereto.

[0083] In the specification, the number of carbon atoms in the carbonyl group is not particularly limited, but may be 1 to 40, 1 to 30, or 1 to 20. For example, the carbonyl group may have the following structure, but embodiments of the present disclosure are not limited thereto.

[0084]

[0085] Above Indicates the location to be connected.

[0086] 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 alkylsulfinyl group and an arylsulfinyl group. The sulfonyl group may include an alkylsulfonyl group and an arylsulfonyl group.

[0087] In the specification, the thio group may include an alkylthio group and an arylthio group. The thio group may refer to a sulfur atom bonded to an alkyl group or an aryl group as defined herein. The alkyl group in the alkylthio group may be linear, branched or cyclic. The number of carbon atoms in the alkylthio group is not specifically limited, but may be, for example, 1 to 20 or 1 to 10. The number of carbon atoms in the arylthio group is not specifically limited, but may be, for example, 6 to 30, 6 to 20 or 6 to 15. Examples of thio groups may include methylthio, ethylthio, propylthio, pentylthio, hexylthio, octylthio, dodecylthio, cyclopentylthio, cyclohexylthio, phenylthio and / or naphthylthio, etc., but embodiments of the present disclosure are not limited thereto.

[0088] In the specification, an oxy group may refer to an oxygen atom bonded to an alkyl or aryl group as defined herein. The oxy group may include an alkoxy group and an aryloxy group. The alkoxy group may be linear, branched or cyclic. 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. The number of carbon atoms in the aryloxy group is not specifically limited, but may be, for example, 6 to 30, 6 to 20 or 6 to 15. Examples of oxy groups may include methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, octyloxy, nonyloxy, decyloxy and / or benzyloxy, etc., but embodiments of the present disclosure are not limited thereto.

[0089] Boryl in this article may refer to a boron atom bonded to an alkyl or aryl group as defined herein. Boryl includes alkylboryl and arylboryl. The alkyl in the alkylboryl may be linear, branched or cyclic. The number of carbon atoms in the alkylboryl is not specifically limited, but may be, for example, 1 to 20 or 1 to 10. The number of carbon atoms in the arylboryl is not specifically limited, but may be, for example, 6 to 30, 6 to 20 or 6 to 15. Examples of boryl may include dimethylboryl, tert-butylmethylboryl, diphenylboryl and / or phenylboryl, etc., but embodiments of the present disclosure are not limited thereto.

[0090] In the specification, the phosphine oxide group may mean an alkyl group or an aryl group defined above combined with -P(=O)-. The number of carbon atoms of the phosphine oxide group is not specifically limited, but may be 1 to 30, 1 to 20, or 1 to 10. The phosphine oxide group may include an alkyl phosphine oxide group and an aryl phosphine oxide group. For example, the phosphine oxide group may have the following structure, but is not limited thereto.

[0091]

[0092] The "*-" above indicates the location to be connected.

[0093] In the specification, the phosphinosulfide group may mean an alkyl or aryl group defined above in combination with -P(=S)-. The number of carbon atoms of the phosphinosulfide group is not specifically limited, but may be 1 to 30, 1 to 20, or 1 to 10. The phosphinosulfide group may include an alkylphosphinosulfide group and an arylphosphinosulfide group. For example, the phosphinosulfide group may have the following structure, but is not limited thereto.

[0094]

[0095] The "*-" above indicates the location to be connected.

[0096] In the description, directly linked may mean a single bond (eg, a single covalent bond).

[0097] Hereinafter, a light emitting element, an ink composition, and a display device including the light emitting element according to an embodiment of the present disclosure will be explained by referring to the accompanying drawings. Figure 1 is a perspective view showing a display device according to an embodiment.

[0098] refer to Figure 1 , the display device DD of the embodiment may be a device activated by an electrical signal. For example, the display device DD may be a large device, such as a television, a monitor and / or an external billboard. In an embodiment, the display device DD may be a small device and / or a medium-sized device, such as a personal computer, a laptop computer, a personal digital terminal, a car navigation unit, a game console, a smart phone, a tablet computer and / or a camera. The foregoing is only presented as an example, and the display device DD may be used as other electronic devices unless it deviates from the present disclosure.

[0099] The display device DD may display an image (or video) through a display surface DD-IS. The display surface DD-IS may be parallel to a plane defined by the first direction axis DR1 and the second direction axis DR2. The display surface DD-IS may include a display area DA and a non-display area NDA.

[0100] In the display area DA, the pixel PX may be provided, and in the non-display area NDA, the pixel PX may not be provided. The non-display area NDA may be defined along the edge of the display surface DD-IS. The non-display area NDA may surround the display area DA. However, the embodiments of the present disclosure are not limited thereto, and the non-display area NDA may be omitted, or the non-display area NDA may be provided only on one side of the display area DA.

[0101] exist Figure 1 , a display device DD provided with a flat display surface DD-IS is shown, but the embodiments of the present disclosure are not limited thereto. The display device DD may include a curved display surface or a three-dimensional display surface. The three-dimensional display surface may include a plurality of display areas indicating different directions from each other.

[0102] exist Figure 1 In the following drawings, the first direction axis DR1 to the third direction axis DR3 are shown, and the directions indicated by the first direction axis to the third direction axis DR1, DR2 and DR3 explained in the description are relative concepts and can be converted into other directions. In an embodiment, the directions indicated by the first direction axis to the third direction axis DR1, DR2 and DR3 can be interpreted as the first direction to the third direction, and the same reference numerals can be used. In the description, the first direction axis DR1 and the second direction axis DR2 can be orthogonal to each other, and the third direction axis DR3 can be the normal direction of the plane defined by the first direction axis DR1 and the second direction axis DR2. In the description, the term "plane" means a plane defined by the first direction axis DR1 and the second direction axis DR2, and the term "cross section" can mean a surface perpendicular to the plane defined by the first direction axis DR1 and the second direction axis DR2 and parallel to the third direction axis DR3. The thickness direction of the display device DD can be a direction parallel to the third direction axis DR3 as the normal direction of the plane defined by the first direction axis DR1 and the second direction axis DR2.

[0103] In the description, the top surface (or front surface) and the bottom surface (or rear surface) of the components constituting the display device DD may be defined based on the third directional axis DR3. In an embodiment, for one element, the surface relatively adjacent to the display surface DD-IS among the two facing surfaces (e.g., opposite surfaces) based on the third directional axis DR3 may be defined as the front surface (or top surface), and the surface relatively separated (e.g., facing away) from the display surface DD-IS may be defined as the rear surface (or bottom surface). In the description, the upper portion (or upper side) or the lower portion (or lower side) may be defined based on the third directional axis DR3, and the upper portion (or upper side) may be defined as the direction close to the display surface DD-IS, and the lower portion (lower side) may be defined as the direction away from the display surface DD-IS.

[0104] In the description, the statement that one element is "directly on" another element / "formed directly on" another element may mean that there is no third element between the one element and the other element. For example, the statement that one element is "directly on" another element / "formed directly on" another element may mean that one element and the other element are "in contact with each other."

[0105] Figure 2 To show along Figure 1 A cross-sectional view of the portion taken along line II' in FIG. Figure 2 may be a cross-sectional view of a display device according to an embodiment.

[0106] The display device DD may include a display panel DP and an optical layer PP on the display panel DP. The display panel DP may include a base layer BS, a circuit layer DP-CL on the base layer BS, a display element layer DP-EL on the circuit layer DP-CL, and an encapsulation layer TFE on the display element layer DP-EL.

[0107] The display panel DP may be an element that basically generates an image. The display panel DP may be an emissive display panel. For example, the display panel DP may be a quantum dot emission display panel including quantum dot light emitting elements.

[0108] The base layer BS may be a member that provides a base surface for the circuit layer DP-CL. The base layer BS may be a rigid substrate or a flexible substrate, and the flexible substrate may be bent, folded, and / or rolled up, etc. The base layer BS may be a glass substrate, a metal substrate, and / or a polymer substrate. However, the embodiments of the present disclosure are not limited thereto, and the base layer BS may be an inorganic layer, an organic layer, or a composite material layer (e.g., a composite material layer including an inorganic material and an organic material).

[0109] The circuit layer DP-CL may be on the base layer BS. The circuit layer DP-CL may include an insulating layer (e.g., an electrical insulating layer), a semiconductor pattern, a conductive pattern (e.g., an electrical conductivity pattern), and a signal line. After forming an insulating layer (e.g., an electrical insulating layer), a semiconductor layer, and a conductive layer (e.g., an electrical conductivity layer) on the base layer BS by coating and / or deposition, the insulating layer, the semiconductor layer, and the conductive layer may be selectively patterned by multiple photoetching processes. Thereafter, the semiconductor pattern, the conductive pattern (e.g., the electrical conductivity pattern), and the signal line included in the circuit layer DP-CL may be formed.

[0110] The display element layer DP-EL may be on the circuit layer DP-CL. The display element layer DP-EL may include a pixel definition layer PDL ( Figure 4 ), and the first to third light-emitting elements ED-1, ED-2 and ED-3 ( Figure 4 ), which will be further explained below. For example, the display element layer DP-EL may include an organic light-emitting material, an inorganic light-emitting material, an organic-inorganic light-emitting material, a quantum dot, a quantum rod, a micro-LED and / or a nano-LED. In an embodiment, the display element layer DP-EL may include a quantum dot.

[0111] The encapsulation layer TFE may protect the display element layer DP-EL from moisture, oxygen and / or foreign matter (such as dust particles). The encapsulation layer TFE may include at least one inorganic layer. The encapsulation layer may include an inorganic layer, an organic layer and an inorganic layer stacked structure in sequence.

[0112] The optical layer PP may be on the display panel DP and may control light reflected by external light at the display panel DP. The optical layer PP may include, for example, a polarizing layer and / or a color filter layer CFL ( Figure 4 ). In an embodiment, the optical layer PP may be omitted.

[0113] Figure 3 It is a plan view showing a display device according to an embodiment. Figure 4 To show along Figure 3 A cross-sectional view of the portion taken along line II-II'. Figure 4 This is a cross-sectional view showing a display device according to an embodiment.

[0114] refer to Figure 3 and Figure 4 , the display device DD may include a peripheral area NPXA and light-emitting areas PXA-R, PXA-G, and PXA-B. The light-emitting areas PXA-R, PXA-G, and PXA-B may be areas that emit light generated from the light-emitting elements ED-1, ED-2, and ED-3, respectively. The areas of the light-emitting areas PXA-R, PXA-G, and PXA-B may be different from each other, and in an embodiment, the term "area" may mean an area on a plane.

[0115] The light emitting regions PXA-R, PXA-G, and PXA-B may be divided into a plurality of groups according to the colors of the lights generated from the light emitting elements ED-1, ED-2, and ED-3. Figure 3 and Figure 4 In the embodiment, three light emitting regions PXA-R, PXA-G and PXA-B emitting red, green and blue light are explained as an embodiment. For example, the display device DD of the embodiment may include a red light emitting region PXA-R, a green light emitting region PXA-G and a blue light emitting region PXA-B separated from each other.

[0116] The display panel DP may include a plurality of light emitting elements ED-1, ED-2, and ED-3 that emit light in different wavelength regions from each other. The plurality of light emitting elements ED-1, ED-2, and ED-3 may emit light of different colors from each other. For example, the display panel DP may include a first light emitting element ED-1 that emits blue light, a second light emitting element ED-2 that emits green light, and a third light emitting element ED-3 that emits red light. However, the embodiments of the present disclosure are not limited thereto, and the first to third light emitting elements ED-1, ED-2, and ED-3 may emit light in the same wavelength region, or at least one of them may emit light in different wavelength regions.

[0117] exist Figure 3 and Figure 4 In the display device DD of the embodiment shown in , the light-emitting regions PXA-R, PXA-G and PXA-B may have different areas according to the colors emitted by the emission layers EML-B, EML-G and EML-R of the light-emitting elements ED-1, ED-2 and ED-3. The blue light-emitting region PXA-B of the first light-emitting element ED-1 that emits blue light may have the largest area, and the green light-emitting region PXA-G of the second light-emitting element ED-2 that emits green light may have the smallest area. However, the embodiments of the present disclosure are not limited thereto, and the light-emitting regions PXA-R, PXA-G and PXA-B may emit light of a color different from red light, green light and blue light. In addition, the light-emitting regions PXA-R, PXA-G and PXA-B may have the same area, or the light-emitting regions PXA-R, PXA-G and PXA-B may have different areas. Figure 3 The area ratios shown in the figure are different area ratios.

[0118] Each of the light-emitting regions PXA-R, PXA-G, and PXA-B may have an area divided (or defined) by the pixel defining layer PDL. The peripheral area NPXA may be an area between adjacent light-emitting regions PXA-R, PXA-G, and PXA-B, and may be an area corresponding to the pixel defining layer PDL. Each of the light-emitting regions PXA-R, PXA-G, and PXA-B may correspond to a pixel.

[0119] The pixel defining layer PDL can define the light emitting regions PXA-R, PXA-G, and PXA-B. The light emitting regions PXA-R, PXA-G, and PXA-B and the peripheral region NPXA can be divided (or defined) by the pixel defining layer PDL.

[0120] The blue light emitting region PXA-B and the red light emitting region PXA-R can be alternately provided along the first direction axis DR1 to form the first group PXG1. The green light emitting region PXA-G can be provided along the first direction axis DR1 to form the second group PXG2. The first group PXG1 can be provided separately from the second group PXG2 along the second direction axis DR2. A plurality of first groups PXG1 and a plurality of second groups PXG2 can be provided. The first group PXG1 and the second group PXG2 can be alternately provided along the second direction axis DR2.

[0121] One red light emitting region PXA-R can be provided separately from one green light emitting region PXA-G along the fourth direction axis DR4. One blue light emitting region PXA-B can be provided separately from one green light emitting region PXA-G along the fifth direction axis DR5. The fourth direction axis DR4 can be a direction between the first direction axis DR1 and the second direction axis DR2. The fifth direction axis DR5 can be a direction that intersects the fourth direction axis DR4 and is inclined with respect to the second direction axis DR2.

[0122] In an embodiment, the arrangement structure of the light emitting regions PXA-R, PXA-G, and PXA-B is not limited to Figure 3 the arrangement structure shown. For example, among the light emitting regions PXA-R, PXA-G, and PXA-B, the red light emitting region PXA-R, the green light emitting region PXA-G, and the blue light emitting region PXA-B can be alternately provided along the first direction axis DR1. In an embodiment, on a plane, the shapes of the light emitting regions PXA-R, PXA-G, and PXA-B are not limited to the shapes shown in the drawings, and can be defined as shapes different from the shapes shown in the drawings.

[0123] In Figure 4 it, the base layer BS can include a single-layer structure or a multi-layer structure. For example, the base layer BS can include a first synthetic resin layer, an interlayer with a multi-layer or single-layer structure, and a second synthetic resin layer. The interlayer can also be referred to as a base isolation layer. The interlayer can include a silicon oxide (SiO x , 0 < x ≤ 2) layer and / or an amorphous silicon (a-Si) layer on the silicon oxide layer, but the embodiments of the present disclosure are not specifically limited thereto. For example, the interlayer can include at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, and an amorphous silicon layer.

[0124] At least one of the first synthetic resin layer and the second synthetic resin layer may include a polyimide resin. In an embodiment, at least one of the first synthetic resin layer and the second synthetic resin layer may include at least one of an acrylate resin (e.g., a methacrylate resin), a polyisoprene resin, a vinyl resin, an epoxy resin, a urethane resin, a cellulose resin, a silicone resin, a polyamide resin, and a perylene resin. In the description, the "~~" resin means a resin including the "~~" functional group.

[0125] The circuit layer DP-CL may be on the base layer BS, and the circuit layer DP-CL may include a plurality of transistors. Each transistor may include a control electrode, an input electrode, and an output electrode. For example, the circuit layer DP-CL may include switching transistors and driving transistors for driving the light-emitting elements ED-1, ED-2, and ED-3 of the display element layer DP-EL.

[0126] The display element layer DP-EL may include a pixel defining layer PDL and first to third light-emitting elements ED-1, ED-2, and ED-3. In the pixel defining layer PDL, a pixel opening portion OH may be defined. The pixel defining layer PDL may divide the first to third light-emitting elements ED-1, ED-2, and ED-3. The emission layers EML-B, EML-G, and EML-R of the first to third light-emitting elements ED-1, ED-2, and ED-3 may be provided and divided in the pixel opening portion OH defined in the pixel defining layer PDL.

[0127] The pixel defining layer PDL may be formed using a polymer resin. For example, the pixel defining layer PDL may be formed by including a polyacrylate resin and / or a polyimide resin. In an embodiment, the pixel defining layer PDL may be formed by further including an inorganic material in addition to the polymer resin. In an embodiment, the pixel defining layer PDL may be formed by including a light-absorbing material and / or by including a black pigment and / or a black dye. The pixel defining layer PDL formed by including a black pigment and / or a black dye may provide a black pixel defining layer. During the formation of the pixel defining layer PDL, carbon black or the like may be used as the black pigment and / or the black dye, but the embodiments of the present disclosure are not limited thereto.

[0128] In an embodiment, the pixel defining layer PDL may be formed using an inorganic material. For example, the pixel defining layer PDL may be formed using an inorganic material including silicon nitride (SiN y ), silicon oxide (SiO x ), and / or silicon oxynitride (SiO x N y ), etc. 0 < x ≤ 2, 0 < y ≤ 4 / 3. For example, x is 0.5 and y is 1.

[0129] The light-emitting elements ED-1, ED-2 and ED-3 may include a first electrode EL1, hole transport regions HTR-1, HTR-2 and HTR-3 on the first electrode EL1, emission layers EML-B, EML-G and EML-R on the hole transport regions HTR-1, HTR-2 and HTR-3, electron transport regions ETR-1, ETR-2 and ETR-3 on the emission layers EML-B, EML-G and EML-R, and a second electrode EL2 on the electron transport regions ETR-1, ETR-2 and ETR-3.

[0130] The first electrode EL1 may be exposed at the pixel opening portion OH of the pixel defining layer PDL. The first electrode EL1 has electrical conductivity (e.g., electrical conductivity). The first electrode EL1 may be formed using a metal material, a metal alloy and / or a conductive compound (e.g., a conductive compound). The first electrode EL1 may be a cathode or an anode. However, the embodiments of the present disclosure are not limited thereto. In an embodiment, the first electrode EL1 may be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a transflective electrode or a reflective electrode. The first electrode EL1 may include at least one selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn and Zn, a compound selected from two or more thereof, a mixture selected from two or more thereof, or an oxide thereof.

[0131] If the first electrode EL1 is a transmissive electrode, the first electrode EL1 may include a transparent metal oxide, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO), etc. If the first electrode EL1 is a transflective electrode or a reflective electrode, the first electrode EL1 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, a compound thereof, or a mixture thereof (for example, a mixture of Ag and Mg), or a material having a multilayer structure such as LiF / Ca (a stacked structure of LiF and Ca) or LiF / Al (a stacked structure of LiF and Al). In an embodiment, the first electrode EL1 may have a structure including a plurality of layers including a reflective layer or a transflective layer formed using the above materials, and a transmissive conductive layer formed using ITO, IZO, ZnO, and / or ITZO. For example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO without limitation. In an embodiment, the first electrode EL1 may include the above metal material, a combination of two or more metal materials selected from the above metal materials, and / or an oxide of the above metal material. However, the embodiments of the present disclosure are not limited thereto. The thickness of the first electrode EL1 may be about 1000 Å. to about For example, the thickness of the first electrode EL1 may be about to about

[0132] The second electrode EL2 may be a common electrode. The second electrode EL2 may be an anode or a cathode, but the embodiments of the present disclosure are not limited thereto. For example, if the first electrode EL1 is an anode, the second electrode EL2 may be a cathode, and if the first electrode EL1 is a cathode, the second electrode EL2 may be an anode. The second electrode EL2 may include at least one selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, and Zn, a compound selected from two or more thereof, a mixture selected from two or more thereof, or an oxide thereof.

[0133] The second electrode EL2 may be a transmissive electrode, a transflective electrode, or a reflective electrode. If the second electrode EL2 is a transmissive electrode, the second electrode EL2 may include a transparent metal oxide such as ITO, IZO, ZnO, ITZO, or the like.

[0134] If the second electrode EL2 is a transflective electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, Yb, W, a compound including the same or a mixture thereof (e.g., AgMg, AgYb and / or MgYb), or a material having a multilayer structure such as LiF / Ca or LiF / Al. In an embodiment, the second electrode EL2 may have a multilayer structure including a reflective layer or a transflective layer formed using the above materials and a transparent conductive layer formed using ITO, IZO, ZnO, ITZO, etc. For example, the second electrode EL2 may include the aforementioned metal material, a combination of two or more metal materials selected from the aforementioned metal materials, and / or an oxide of the aforementioned metal material.

[0135] In an embodiment, the second electrode EL2 may be connected to the auxiliary electrode. If the second electrode EL2 is connected to the auxiliary electrode, the resistance (eg, electronic resistance) of the second electrode EL2 may be reduced.

[0136] Between the first electrode EL1 and the second electrode EL2, emission layers EML-B, EML-G, and EML-R may be provided. The first light emitting element ED-1 may include a first emission layer EML-B, the second light emitting element ED-2 may include a second emission layer EML-G, and the third light emitting element ED-3 may include a third emission layer EML-R. The first emission layer EML-B may include a first quantum dot QD-C1. The second emission layer EML-G may include a second quantum dot QD-C2. The third emission layer EML-R may include a third quantum dot QD-C3.

[0137] The quantum dots QD-C1, QD-C2, and QD-C3 included in the emission layers EML-B, EML-G, and EML-R may be stacked to form a layer. Figure 4 In the embodiment, quantum dots QD-C1, QD-C2 and QD-C3 having a circular cross-section are provided to form approximately two layers, but the embodiments of the present disclosure are not limited thereto. For example, according to the thickness of the emission layers EML-B, EML-G and EML-R, the shapes of the quantum dots QD-C1, QD-C2 and QD-C3 included in the emission layers EML-B, EML-G and EML-R, and the average diameter of the quantum dots QD-C1, QD-C2 and QD-C3, the arrangement of the quantum dots QD-C1, QD-C2 and QD-C3 may be changed. In an embodiment, the quantum dots QD-C1, QD-C2 and QD-C3 in the emission layers EML-B, EML-G and EML-R may be provided to form one layer, or may be provided to form multiple layers such as two layers or three layers.

[0138] The first quantum dot QD-C1 of the first light-emitting element ED-1 may emit blue light. The second quantum dot QD-C2 of the second light-emitting element ED-2 may emit green light. The third quantum dot QD-C3 of the third light-emitting element ED-3 may emit red light. Each of the quantum dots QD-C1, QD-C2, and QD-C3 may include a core and a shell surrounding the core. Accordingly, each of the quantum dots QD-C1, QD-C2, and QD-C3 may include a core-shell structure. The cores of the quantum dots QD-C1, QD-C2, and QD-C3 may include materials different from each other. Differently, the cores of the quantum dots QD-C1, QD-C2, and QD-C3 may include the same material. In an embodiment, two cores selected from the cores of the quantum dots QD-C1, QD-C2, and QD-C3 may include the same material, and the remaining one core may include a different material.

[0139] exist Figure 4, the diameters of the first to third quantum dots QD-C1, QD-C2, and QD-C3 are shown to be similar, but the embodiments of the present disclosure are not limited thereto. The diameters of the first to third quantum dots QD-C1, QD-C2, and QD-C3 may be different from each other. For example, when compared with the second quantum dot QD-C2 of the second light-emitting element ED-2 and the third quantum dot QD-C3 of the third light-emitting element ED-3, the first quantum dot QD-C1 of the first light-emitting element ED-1 emitting light in a relatively short wavelength region may have a relatively smaller average diameter. The average diameter corresponds to the arithmetic mean of the particle sizes of the plurality of quantum dots. The particle size of the quantum dot may be the average value of the width of the cross section of the quantum dot particle.

[0140] In an embodiment, the electron transport regions ETR-1, ETR-2 and ETR-3 may include nanoparticles NP ( Figure 5 ), which will be further explained below. The following will explain in more detail the nanoparticle NP ( Figure 5 ).

[0141] The hole transport regions HTR-1, HTR-2, and HTR-3 of the first to third light-emitting elements ED-1, ED-2, and ED-3 may be divided or defined in the pixel opening portion OH. The first light-emitting element ED-1 may include a first hole transport region HTR-1, the second light-emitting element ED-2 may include a second hole transport region HTR-2, and the third light-emitting element ED-3 may include a third hole transport region HTR-3.

[0142] Each of the hole transport regions HTR-1, HTR-2, and HTR-3 may have a single-layer structure formed using a single material, a single-layer structure formed using a plurality of different materials, or a multi-layer structure including a plurality of layers formed using a plurality of different materials. The thickness of the first to third hole transport regions HTR-1, HTR-2, and HTR-3 may be, for example, about to about The thickness of the first to third hole transport regions HTR-1, HTR-2, and HTR-3 may be, for example, about to about For example, about to about

[0143] The first to third hole transport regions HTR-1, HTR-2, and HTR-3 may further include any suitable hole injection material and / or any suitable hole transport material. For example, the first to third hole transport regions HTR-1, HTR-2, and HTR-3 may include phthalocyanine compounds (such as copper phthalocyanine), N 1 ,N 1'-([1,1'-biphenyl]-4,4'-diyl)bis(N 1 -phenyl-N 4 ,N 4 -Di-m-tolylbenzene-1,4-diamine)(DNTPD), 4,4',4"-[tri(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4',4"-tri(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tri[N-(2-naphthyl)-N-phenylamino]triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), polyaniline / camphorsulfonic acid (PANI / CSA) , polyaniline / poly(4-styrene sulfonate) (PANI / PSS), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB), triphenylamine-containing polyetherketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium[tetrakis(pentafluorophenyl)borate], poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)] (TFB) and / or dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN).

[0144] In an embodiment, the first to third hole transport regions HTR-1, HTR-2, and HTR-3 may include carbazole derivatives (such as N-phenylcarbazole and / or polyvinylcarbazole), fluorene derivatives, triphenylamine derivatives (such as N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4,4',4"-tri(N-carbazolyl)triphenylamine (TCTA), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB), 4,4'-diphenyl ... 4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4'-bis[N,N'-(3-methylphenyl)amino]-3,3'-dimethylbiphenyl (HMTPD), 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi), 9-phenyl-9H-3,9'-bicarbazole (CCP), 1,3-bis(N-carbazolyl)benzene (mCP), or 1,3-bis(1,8-dimethyl-9H-carbazol-9-yl)benzene (mDCP)).

[0145] The electron transport regions ETR-1, ETR-2, and ETR-3 of the first to third light emitting elements ED-1, ED-2, and ED-3 may be provided and divided in the pixel opening portion OH. The first light emitting element ED-1 may include a first electron transport region ETR-1, the second light emitting element ED-2 may include a second electron transport region ETR-2, and the third light emitting element ED-3 may include a third electron transport region ETR-3.

[0146] Each of the first to third electron transport regions ETR-1, ETR-2, and ETR-3 may have a single-layer structure formed using a single material, a single-layer structure formed using a plurality of different materials, or a multi-layer structure having a plurality of layers formed using different materials. The thickness of the first to third electron transport regions ETR-1, ETR-2, and ETR-3 may be, for example, about to about

[0147] In addition to the above-mentioned nanoparticles NP ( Figure 5 ), the first to third electron transport regions ETR-1, ETR-2, and ETR-3 may further include any suitable electron injection material and / or any suitable electron transport material. For example, the electron transport region ETR may include an anthracene compound. In an embodiment, the first to third electron transport regions ETR-1, ETR-2, and ETR-3 may include, for example, tris(8-hydroxyquinoline)aluminum (Alq 3 ), 1,3,5-tris[(3-pyridyl)-phenyl-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 2,9-dimethyl-4,7-diphenyl 1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole ( t Bu-PBD), bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), bis(benzoquinoline-10-hydroxy)beryllium (Bebq 2), 9,10-di(naphthalene-2-yl)anthracene (ADN), 1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene (BmPyPhB) and mixtures thereof. In addition, the electron transport region ETR may include 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), diphenyl(4-(triphenylsilyl)phenyl)phosphine oxide (TSPO1) and / or 4,7-diphenyl-1,10-phenanthroline (Bphen) and the like.

[0148] The encapsulation layer TFE may include at least one inorganic layer (hereinafter, encapsulation inorganic layer). In an embodiment, the encapsulation layer TFE may include at least one organic layer (hereinafter, encapsulation organic layer) and at least one encapsulation inorganic layer.

[0149] The encapsulated inorganic layer can protect the display element layer DP-EL from moisture / oxygen, and the encapsulated organic layer can protect the display element layer DP-EL from foreign matter (such as dust particles). The encapsulated inorganic layer may include silicon nitride, silicon oxynitride, silicon oxide, titanium oxide and / or aluminum oxide, without specific restrictions. The encapsulated organic layer may include acrylic compounds, epoxy compounds, etc., and the encapsulated organic layer may include photopolymerizable organic materials, without specific restrictions.

[0150] The optical layer PP may include a base substrate BL and a color filter layer CFL. The base substrate BL may be a member providing a base surface on which the color filter layer CFL is provided. The base substrate BL may be a glass substrate, a metal substrate, and / or a plastic substrate, etc. However, the embodiments of the present disclosure are not limited thereto, but the base substrate BL may be an inorganic layer, an organic layer, or a composite material layer (e.g., a composite material layer including an organic material and an inorganic material).

[0151] The color filter layer CFL may include first to third filters CF-B, CF-G, and CF-R. The first to third filters CF-B, CF-G, and CF-R may be provided corresponding to the first to third light-emitting elements ED-1, ED-2, and ED-3, respectively. For example, the first filter CF-B may be a blue filter, the second filter CF-G may be a green filter, and the third filter CF-R may be a red filter. The first to third filters CF-B, CF-G, and CF-R may be provided corresponding to the light-emitting regions PXA-B, PXA-G, and PXA-R, respectively.

[0152] Each of the first to third filters CF-B, CF-G, and CF-R may include a photosensitive polymer resin and a pigment and / or a dye. The first filter CF-B may include a blue pigment and / or a blue dye, the second filter CF-G may include a green pigment and / or a green dye, and the third filter CF-R may include a red pigment and / or a red dye. However, the embodiments of the present disclosure are not limited thereto, and the first filter CF-B may not include a pigment and / or a dye. The first filter CF-B may include a photosensitive polymer resin without including a pigment or a dye. The first filter CF-B may be transparent. The first filter CF-B may be formed using a transparent photosensitive resin.

[0153] The color filter layer CFL may further include a buffer layer BFL. For example, the buffer layer BFL may be a protective layer that protects the first to third filters CF-B, CF-G, and CF-R. The buffer layer BFL may be an inorganic layer including at least one inorganic material of silicon nitride, silicon oxide, and silicon oxynitride. The buffer layer BFL may be formed as a single layer or a plurality of layers.

[0154] In an embodiment, the second filter CF-G and the third filter CF-R may be yellow filters. The second filter CF-G and the third filter CF-R may be provided as one body without being distinguished.

[0155] In an embodiment, the color filter layer CFL may further include a light blocking member. The light blocking member may be a black matrix. The light blocking member may be formed by including an organic light blocking material and / or an inorganic light blocking material including a black pigment and / or a black dye. The light blocking member may prevent or reduce light leakage and may divide a boundary between adjacent filters CF-B, CF-G, and CF-R.

[0156] Figure 5 1 is a cross-sectional view showing a light emitting element ED according to an embodiment. Figure 5 The light emitting element ED explained can be applied in the same way Figure 4 At least one of the first to third light emitting elements ED-1, ED-2 and ED-3 shown in FIG.

[0157] refer to Figure 5, the light emitting element ED 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 stacked in sequence. The hole transport region HTR may include a hole injection layer HIL and a hole transport layer HTL. The hole injection layer HIL may be on the first electrode EL1, and the hole transport layer HTL may be on the hole injection layer HIL. The electron transport region ETR may include an electron transport layer ETL and an electron injection layer EIL. The electron injection layer EIL may be on the electron transport layer ETL, and the second electrode EL2 may be on the electron injection layer EIL. In the light emitting element ED, the electron transport region ETR may include the nanoparticles NP of the embodiment.

[0158] The electron transport region ETR may include the nanoparticle NP of the embodiment.

[0159] In an embodiment, the electron transport layer ETL may include the nanoparticles NP of the embodiment. In an embodiment, the electron transport layer ETL and the electron injection layer EIL may include the nanoparticles NP of the embodiment. The electron transport region ETR including the nanoparticles NP of the embodiment may contribute to an increase in electron injection characteristics and / or electron transport characteristics, and thereby contribute to an improvement in the emission efficiency of the light emitting element ED.

[0160] The emission layer EML may include quantum dots QD-C. In the following, the quantum dots QD-C will be applied Figure 4 The same explanation applies to the first to third quantum dots QD-C1, QD-C2, and QD-C3 shown in FIG.

[0161] In the description, quantum dot QD-C refers to a crystal of a semiconductor compound. The quantum dot QD-C may emit light of various appropriate wavelengths according to the size of the crystal. The diameter of the quantum dot QD-C may be, for example, about 1 nm to about 10 nm.

[0162] Quantum dot QD-C can be synthesized by chemical bath deposition, metal organic chemical vapor deposition, molecular beam epitaxy and / or processes similar thereto. Chemical bath deposition is a method of growing quantum dot QD-C particle crystals after mixing an organic solvent and a precursor material together. During the growth of the quantum dot QD-C particle crystals, the organic solvent naturally acts as a dispersant coordinated at the surface of the quantum dot QD-C particle crystals, and the growth of the quantum dot QD-C particle crystals can be controlled. Accordingly, chemical bath deposition is more advantageous than vapor deposition methods such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE), and the growth of quantum dot QD-C particle crystals can be controlled by a low-cost process.

[0163] The quantum dots may include a II-VI semiconductor compound, a I-II-VI semiconductor compound, a II-IV-VI compound, a I-II-IV-VI semiconductor compound, a III-V semiconductor compound, a III-VI semiconductor compound, a I-III-VI semiconductor compound, a IV-VI semiconductor compound, a II-IV-V semiconductor compound, a Group IV element or compound, or any combination thereof. In the description, the term "group" means a group in the IUPAC periodic table.

[0164] Examples of Group II-VI compounds may include binary compounds such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe and MgS, ternary compounds such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe and MgZnS, quaternary compounds such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe, or appropriate combinations thereof. In an embodiment, the II-VI semiconductor compound may further include a metal in Group I and / or an element in Group IV. The I-II-VI compound may be selected from CuSnS or CuZnS, and the II-IV-VI compound may include ZnSnS, etc. The I-II-IV-VI compound may be a quaternary compound selected from the group consisting of: Cu 2 ZnSnS 2 , Cu 2 ZnSnS 4 , Cu 2 ZnSnSe 4 、Ag 2 ZnSnS 2 and mixtures thereof.

[0165] Examples of Group III-V semiconductor compounds may include binary compounds such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, and InSb, ternary compounds such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, and InPSb, quaternary compounds such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb, or appropriate combinations thereof. In an embodiment, the Group III-V semiconductor compound may further include a Group II element. Examples of the Group III-V semiconductor compound including an element in Group II may include InZnP, InGaZnP, InAlZnP, and the like.

[0166] Examples of III-VI semiconductor compounds may include binary compounds such as GaS, Ga 2 S 3 ,GaSe,Ga 2 Se 3 、GaTe、InS、InSe、In 2 Se 3 and InTe, ternary compounds such as InGaS 3 and InGaSe 3 , or a suitable combination thereof.

[0167] Examples of Group I-III-VI semiconductor compounds may include ternary compounds such as AgInS, AgInS 2 、AgInSe 2 、AgGaS、AgGaS 2 、AgGaSe 2 、CuInS、CuInS 2 、CuInSe 2 、CuGaS 2 、CuGaSe 2 、CuGaO 2 、AgGaO 2 and AgAlO 2 , quaternary compounds such as AgInGaS 2 and CuInGaS 2 , or a suitable combination thereof.

[0168] Examples of Group IV-VI semiconductor compounds may include binary compounds such as SnS, SnSe, SnTe, PbS, PbSe and PbTe, ternary compounds such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe and SnPbTe, quaternary compounds such as SnPbSSe, SnPbSeTe and SnPbSTe, or appropriate combinations thereof.

[0169] Examples of Group II-IV-V semiconductor compounds may be ternary compounds selected from the group consisting of: ZnSnP, ZnSnP 2 、ZnSnAs 2 、ZnGeP 2 、ZnGeAs 2 、CdSnP 2 、CdGeP 2 and mixtures thereof.

[0170] The Group IV element or compound may include single element compounds such as Si and Ge, binary compounds such as SiC and SiGe, or a suitable combination thereof.

[0171] Each element included in a multi-element compound (such as a binary compound, a ternary compound, and a quaternary compound) may be present in the particle at a uniform concentration or a non-uniform concentration. In an embodiment, the chemical formula means the type (or kind) of the element included in the compound, and the ratio of the elements in the compound may be different. For example, AgInGaS 2 Can mean AgIn x Ga 1-x S 2 (0 <x<1)。

[0172] In an embodiment, the quantum dot QD-C may have a single structure in which the concentration of each element included in the quantum dot QD-C is uniform (or substantially uniform), or may have a core-shell dual structure. For example, the material included in the core may be different from the material included in the shell.

[0173] The shell of the quantum dot QD-C may act as a protective layer and / or a charging layer, the protective layer being used to prevent or reduce the chemical denaturation of the core and maintain the semiconductor properties, and the charging layer being used to provide the quantum dot with electrophoretic properties. The shell may be a single layer or multiple layers. In a core-shell structure, the shell may have a concentration gradient in which the concentration of the element present in the shell decreases in the direction toward the core.

[0174] Examples of the shell of the quantum dot QD-C may include metal oxides and / or non-metal oxides, semiconductor compounds, or any combination thereof. Examples of metal oxides and / or non-metal oxides may include binary compounds such as SiO2 、Al 2 O 3 、TiO 2 、ZnO、MnO、Mn 2 O 3 , Mn 3 O 4 , CuO, FeO, Fe 2 O 3 , Fe 3 O 4 , CoO, Co 3 O 4 and NiO, ternary compounds such as MgAl 2 O 4 、CoFe 2 O 4 、NiFe 2 O 4 and CoMn 2 O 4 , or a suitable combination thereof. Examples of semiconductor compounds may include II-VI semiconductor compounds, III-V semiconductor compounds, III-VI semiconductor compounds, I-III-VI semiconductor compounds, IV-VI semiconductor compounds, or a suitable combination thereof as described in this specification. For example, the semiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaS, GaSe, AgGaS, AgGaS 2 , GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, etc., or appropriate combinations thereof.

[0175] Each element included in the multi-component compound (such as the binary compound and the ternary compound) may exist in the particle at a uniform concentration or a non-uniform concentration. In an embodiment, the chemical formula means the type (or kind) of elements included in the compound, and the ratio of elements in the compound may be different.

[0176] The quantum dots may have a full width at half maximum (FWHM) of an emission wavelength spectrum of about 45 nm or less, about 40 nm or less, or, for example, about 30 nm or less. Within the above range, color purity and / or color reproducibility may be improved. In an embodiment, light emitted by such quantum dots is emitted in all (or substantially all) directions, and the light viewing angle may be improved.

[0177] In an embodiment, the type (or kind) of quantum dots may be any appropriate type (or kind) generally used in the field and is not specifically limited, but for example, spherical, pyramidal, multi-armed and / or cubic nanoparticles, nanotubes, nanowires, nanofibers, nanoplates, etc. may be used.

[0178] By controlling the size of the quantum dots and / or by controlling the ratio of elements in the quantum dot compound, the energy band gap can be controlled, and various appropriate wavelengths of light can be obtained from the emission layer EML including the quantum dots. Accordingly, by using such quantum dots (by using quantum dots of different sizes and / or by using quantum dots that control the ratio of elements in the quantum dot compound differently), a light-emitting element that emits light of various appropriate wavelengths can be realized. In an embodiment, the size of the quantum dots and / or the ratio of elements in the quantum dot compound can be selected to emit red light, green light, and / or blue light. In an embodiment, quantum dots can be provided to emit white light in combination with various appropriate emission colors.

[0179] Figure 6 A portion of an ink composition according to an embodiment is shown. Figure 7 and Figure 8 A portion of a nanoparticle according to an embodiment is shown.

[0180] refer to Figure 6 , the ink composition IC of the embodiment includes a nanoparticle core NPC, a preliminary ligand PLD and a solvent SL. The nanoparticle core NPC includes a core compound represented by Formula 1. The core compound includes a core metal element A and an oxygen atom.

[0181] Formula 1

[0182] A x O y

[0183] In Formula 1, the core metal element A is Zn or Sn. x and y are each independently an integer selected from 1 to 5. For example, the core compound may be SnO 2 and one of ZnO.

[0184] The preliminary ligand PLD is represented by Formula 4. The preliminary ligand PLD includes a substituted or unsubstituted carboxylate and a ligand metal element M. The ligand metal element M is bonded to an oxygen atom included in the carboxylate.

[0185] Formula 4

[0186]

[0187] In Formula 4, the ligand metal element M is one of Li, Na, K, Rb, Cs, Be, Ca, Sr and Ba. The standard reduction potential of the ligand metal element M may be less than the standard reduction potential of the core metal element A. The absolute value of the standard reduction potential of the ligand metal element M may be greater than the absolute value of the standard reduction potential of the core metal element A. For example, the ligand metal element M may be Ca. 3 and R 4 Each is independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms. 3 and R 4 Each of R and R is independently an unsubstituted methyl group. 3 and R 4 Each of c and d is independently an integer selected from 0 to 3. For example, c may be 2, and d may be 1. In an embodiment, R 3 and R 4 Each of R and R is independently a substituted or unsubstituted alkyl group of 1 to 5 carbon atoms. 3 and R 4 Each of R 3 and R 4 Each of R and R is independently a substituted or unsubstituted alkyl group having 6 to 20 carbon atoms. 3 and R 4 Each may be an unsubstituted n-heptadecanyl group.

[0188] If R 3 and R 4 Each independently is a substituted or unsubstituted alkyl group of 1 to 5 carbon atoms, the solvent SL may include a water-soluble solvent. The weight ratio of the nanoparticle core NPC to the water-soluble solvent may be about 1% to about 10%. For example, the weight ratio of the nanoparticle core NPC to the water-soluble solvent may be about 3%. The solvent SL including the water-soluble solvent may include a first solvent compound represented by Formula 5.

[0189] Formula 5

[0190]

[0191] In Formula 5, R 11 and R 12 Each of R and R is independently a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms. 11 It can be unsubstituted ethylene or unsubstituted propylene.12 It can be an unsubstituted ethylene group or an unsubstituted propylene group. 13 It may be a substituted or unsubstituted alkyl group of 1 to 4 carbon atoms. 13 It may be an unsubstituted isopropyl group, an unsubstituted butyl group or an unsubstituted tert-butyl group. In an embodiment, t may be 1 or 2. The first solvent compound may include at least one of diethylene glycol tert-butyl ether (DGtBE), tripropylene glycol monobutyl ether (TPGBE) and triethylene glycol monoisopropyl ether (TGIPE).

[0192] If R 3 and R 4 Each independently is a substituted or unsubstituted alkyl group of 6 to 20 carbon atoms, the solvent SL may include at least one of cyclohexylbenzene (CHB) and hexadecane.

[0193] Figure 6 The ink composition IC shown in FIG. 1 can be used as an ink for forming an electron transport region ETR ( Figure 5 ) materials. Forming the electron transport region ETR ( Figure 5 ) may include the step of: combining ligands LD1 and LD2 ( Figure 7 and Figure 8 ) is bonded to the surface of each nanoparticle core NPC to form each nanoparticle NP ( Figure 7 and Figure 8 ), providing a method having a nanoparticle NP ( Figure 7 and Figure 8 ) of the ink composition IC of the emission layer EML ( Figure 5 ), and a drying solvent SL.

[0194] Reference together Figure 5 , Figure 7 and Figure 8 , the nanoparticle NP may include a nanoparticle core NPC, the nanoparticle core NPC including a core compound represented by Formula 1 and a ligand LD1 or LD2, the ligand LD1 or LD2 is bonded to the surface of the nanoparticle core NPC and represented by Formula 2 or Formula 3. Display device DD( Figure 4 ) and / or the electron transport region ETR of the light emitting element ED may include nanoparticles NP. In an embodiment, the electron transport layer ETL may include nanoparticles NP. For the core compound and the nanoparticle core NPC, reference may be applied Figure 6 The same contents as explained above. The ligands LD1 and LD2 may include a first ligand LD1 and a second ligand LD2. The first ligand LD1 may be represented by Formula 2, and the second ligand LD2 may be represented by Formula 3. The ligands LD1 and LD2 include a substituted or unsubstituted carboxylate and a ligand metal element M. The ligand metal element M is bonded to an oxygen atom included in the carboxylate.

[0195] Formula 2

[0196]

[0197] Formula 3

[0198]

[0199] In Formula 2 and Formula 3, M is one of Li, Na, K, Rb, Cs, Be, Ca, Sr, and Ba. For example, M may be Ca. 1 and R 2 Each is independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms. 1 It may be an unsubstituted methyl group. 2 may be an unsubstituted n-heptadecanyl group. a and b are each independently an integer selected from 0 to 3. For example, a may be 1. For example, b may be 1. "—*" and is the location where the nanoparticle core NPC is connected.

[0200] The ligands LD1 and LD2 can be obtained by the above-mentioned primary ligand PLD ( Figure 6 ) is formed by decomposition. The ligands LD1 and LD2 can form chemical bonds with the core compound distributed on the surface of the nanoparticle core NPC. For example, the ligands LD1 and LD2 can form ionic bonds with the core compound distributed on the surface of the nanoparticle core NPC. The oxygen atom connected to the "—*" of the first ligand LD1 represented by Formula 2 can have a negative charge and can form an ionic bond with the core metal element A ion of the core compound having a positive charge. The attached ligand metal element M may have a positive charge and may form an ionic bond with the oxygen anion of the core compound. The ligand metal element M of the second ligand LD2 represented by Formula 3 may have a positive charge and may form an ionic bond with the oxygen anion of the core compound.

[0201] In the light emitting element ED or the display device DD ( Figure 4), electrons injected from the electron injection layer EIL toward the electron transport layer ETL can reduce the core metal element A included in the electron transport layer ETL and increase the mobility of the electrons. The core metal element A reduced by electrons has a defect that the function of increasing the mobility of electrons is reduced compared to the mobility before reduction. In order to prevent or reduce such defects, in the present disclosure, ligands LD1 and LD2 including a ligand metal element M cover the nanoparticle core NPC. The standard reduction potential of the ligand metal element M may be less than the standard reduction potential of the core metal element A. In an embodiment, the ligand metal element M is more difficult to be reduced than the core metal element A. Accordingly, if the ligands LD1 and LD2 cover the surface of the nanoparticle core NPC, the core metal element A can be prevented or reduced from being reduced in the light emitting element ED or the display device DD( Figure 4 ) during the driving of the nanoparticle core. The ligands LD1 and LD2 may be provided in plurality and may cover the surface of the nanoparticle core NPC to prevent or reduce the core metal element A of the nanoparticle core NPC from being reduced by electrons.

[0202] The nanoparticle core NPC may be doped with a metal element. The nanoparticle core NPC may be doped with at least one of Zn, Mg, Li, Na, Ni, and Cu. If the nanoparticle core NPC is doped with a metal element, the metal element surrounding the nanoparticle core NPC may be reduced first compared to the core metal element A of the nanoparticle core NPC, and the function of increasing the electron mobility of the core metal element A may be retained.

[0203] Hereinafter, nanoparticles according to an embodiment of the present disclosure and a light emitting element of an embodiment will be explained in more detail with reference to Examples and Comparative Examples. The examples shown below are explanations for helping to understand the embodiments of the present disclosure, and the scope of the present disclosure is not limited thereto.

[0204] Example

[0205] 1. Manufacturing and evaluation of light-emitting components

[0206] (1) Manufacturing of light-emitting elements

[0207] The light-emitting element of the embodiment, which includes the nanoparticles of the embodiment in the electron transport region, is manufactured by the following method.

[0208] Manufacturing of light-emitting components

[0209] The substrate on which ITO was deposited as an anode was cut into a size of 50 mm×50 mm×0.5 mm, each cleaned by ultrasonic cleaning using isopropyl alcohol and pure water for 5 minutes, irradiating with ultraviolet rays for about 30 minutes, and exposing to ozone, and the ITO substrate was installed in a vacuum deposition apparatus.

[0210] On an ITO substrate, poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS) was deposited to form a A hole injection layer with a thickness of about 1000 mm was formed, and on the hole injection layer, poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)] (TFB) was vacuum deposited to form a hole injection layer with a thickness of about 1000 mm. hole transport layer.

[0211] On the hole transport layer, quantum dots with an InP / ZnSe / ZnS structure were spin-coated to about to form an emission layer, and on the emission layer, the nanoparticles of the embodiment are spin-coated to form a layer having a thickness of about On the electron transport layer, Al is deposited to form an electron transport layer having a thickness of about A cathode with a thickness of , thereby manufacturing a light-emitting element.

[0212] The nanoparticles of the embodiment were formed by the following process. Tin (IV) acetate (1 mmol), oleic acid (3.3 ml), oleylamine (3.3 ml) and xylene (30 ml) were added to a reactor and stirred for about 30 minutes under a vacuum atmosphere. N was supplied to the reactor. 2 After the atmosphere is formed, the temperature is raised to about 100°C and the reactor is kept for about 30 minutes. 4+ The mixture was quickly injected with deionized (DI) water (1 ml) and reacted for about 5 hours. After the reaction was completed, the temperature of the mixture was lowered to room temperature and an excess of ethanol was injected therein. 2 Precipitate and disperse in hexane to synthesize SnO 2 Seed crystal. For SnO 2 To further increase the growth of tin(IV) acetate (1 mmol), oleic acid (3.3 ml) and trioctylamine (10 ml) were added to the reactor, the temperature was raised to about 120°C, and stirred for about 30 minutes under a vacuum atmosphere. 2 After the atmosphere, SnO 2 After the reaction is completed, SnO 2 The temperature of the solution was lowered to room temperature, then rinsed twice with hexane and ethanol, and dispersed in cyclohexylbenzene. Calcium acetate (1 mmol) and oleic acid (2 mmol) were mixed with 1-octadecene solvent, and then heated at 200° C. to prepare calcium oleate. Then, the temperature was lowered to 120° C., the synthesized tin oxide was injected therein, vacuum treated for about 10 minutes, and reacted for about 30 minutes.

[0213] The nanoparticles of the comparative example were formed by the following process. Zinc acetate (1 mmol) and magnesium acetate (0.2 mmol) were dissolved in dimethyl sulfoxide (DMSO, 10 ml) to prepare solution A. Trimethylammonium hydroxide (1 mmol) was dissolved in ethanol (5 ml) to prepare solution B. Solution B was slowly injected into solution A and reacted at about 4°C for about 1 hour. After the reaction was completed, acetone (10 ml) and octane (5 ml) were added, and centrifugation was performed to precipitate the nanoparticles. The nanoparticles were redispersed in ethanol.

[0214] (2) Evaluation of characteristics of light-emitting elements

[0215] The driving voltage (V (at 5 mA / cm 2 The results of the evaluation of the light-emitting elements manufactured in the embodiments and comparative examples are shown in Table 1. In order to evaluate the characteristics of the light-emitting elements manufactured in the embodiments and comparative examples, the light-emitting elements were measured at about 5 mA / cm 2 The driving voltage (V) at a current density of , the emission efficiency (Cd / A) at about 2000 nits, and the absolute time taken from the initial brightness to 90% brightness were measured as the lifetime (at T90).

[0216] Table 1

[0217]

[0218] It can be seen from the results of reference Table 1 that, compared with the light-emitting element of the comparative example, the light-emitting element of the embodiment using the nanoparticles according to the embodiment of the present disclosure as the material of the electron transport layer shows a relatively low driving voltage, a high emission efficiency and a long element life. The core metal element included in the light-emitting element of the embodiment and the comparative example plays a role in controlling the mobility of the electrons injected during the driving of the light-emitting element. If the core metal element is reduced by electrons, the function of the core metal element to control the electron mobility will deteriorate. If the electron mobility is not controlled and the electron mobility is reduced, the current density can be reduced, and the electric field value of the electron transport layer can be increased. If the electric field value of the electron transport layer increases, the degradation of the light-emitting element will be accelerated, and therefore, the life span can be reduced, and the emission efficiency can be reduced. In the light-emitting element of the embodiment, a ligand of a ligand metal element having a standard reduction potential lower than the standard reduction potential of the core metal element A covers the nanoparticle core. Accordingly, the core metal element A can be prevented or reduced from being reduced by the electrons injected during the driving of the light-emitting element of the embodiment, the electron mobility can be easily controlled, and the emission efficiency and life span of the light-emitting element can be improved. However, in the light-emitting element of the comparative example, the core metal element A and the ligand metal element are the same (Zn), the standard reduction potential value is the same, and although the ligand covers the nanoparticle core, the function of preventing or reducing the reduction of the core metal element may be degraded. Accordingly, the mobility of electrons cannot be controlled, the mobility of electrons may be reduced, and the emission efficiency and lifespan may be reduced.

[0219] The light emitting element of the embodiment may show improved element characteristics of high emission efficiency and long lifetime.

[0220] The ink composition of the embodiment may help increase the emission efficiency and lifetime of the light emitting element.

[0221] The display device of the embodiment may include a light emitting element having excellent emission efficiency and lifetime.

[0222] Although example embodiments of the present disclosure have been described, it should be understood that the present disclosure should not be limited to these embodiments, but a person skilled in the art may make various changes and modifications within the spirit and scope of the present disclosure as claimed.

Claims

1. An ink composition comprising: A nanoparticle core comprising a core compound represented by the following Formula 1; The preliminary ligand is represented by the following formula 4; as well as A solvent in which the nanoparticle core and the preliminary ligand are dispersed: Formula 1 THE x THE y Formula 4 In formula 1, A is Zn or Sn, and x and y are each independently an integer selected from 1 to 5, In formula 4, M is one of Li, Na, K, Rb, Cs, Be, Ca, Sr and Ba, R3 and R4 are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms, and c and d are each independently an integer selected from 0 to 3.

2. The ink composition according to claim 1, wherein In Formula 4, R3 and R4 are each independently a substituted or unsubstituted alkyl group of 1 to 5 carbon atoms.

3. The ink composition according to claim 2, wherein the solvent comprises a water-soluble solvent. 4 . The ink composition according to claim 3 , wherein a weight ratio of the nanoparticle core to the water-soluble solvent is 1% to 10%.

5. The ink composition according to claim 3, wherein the water-soluble solvent comprises a first solvent compound represented by the following Formula 5: Formula 5 In formula 5, R 11 and R 12 are each independently a substituted or unsubstituted alkylene group of 1 to 4 carbon atoms, R 13 is a substituted or unsubstituted alkyl group of 1 to 4 carbon atoms, and t is 1 or 2. 6 . The ink composition according to claim 5 , wherein the first solvent compound comprises at least one of diethylene glycol tert-butyl ether, tripropylene glycol monobutyl ether, and triethylene glycol monoisopropyl ether.

7. The ink composition according to claim 1, wherein In Formula 4, R3 and R4 are each independently a substituted or unsubstituted alkyl group of 6 to 20 carbon atoms.

8. The ink composition according to claim 7, wherein the solvent comprises at least one of cyclohexylbenzene and hexadecane.

9. A light emitting element, comprising: a first electrode; a hole transport region on the first electrode; an emitting layer on the hole transport region; an electron transport region on the emissive layer; as well as a second electrode on the electron transport region, wherein the electron transport region comprises a nanoparticle comprising a nanoparticle core and a ligand, The nanoparticle core includes a core compound represented by the following formula 1, and The ligand is bonded to the surface of the nanoparticle core and is represented by the following Formula 2 or Formula 3: Formula 1 THE x THE y Formula 2 Formula 3 In formula 1, A is Zn or Sn, and x and y are each independently an integer selected from 1 to 5, In formula 2, M is one of Li, Na, K, Rb, Cs, Be, Ca, Sr and Ba, R1 is a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms, a is an integer selected from 0 to 3, and and are each a location attached to the nanoparticle core, and In formula 3, R2 is a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms, M is the same as M defined in Formula 2, b is an integer from 0 to 3, and is the location where the nanoparticle core is connected.

10. A display device, comprising: Basal layer; a circuit layer on the base layer; as well as a display element layer on the circuit layer and including light emitting elements, in: The light emitting element includes a first electrode, a second electrode on the first electrode, and an electron transport region between the first electrode and the second electrode. The electron transport region includes a nanoparticle including a nanoparticle core and a ligand, The nanoparticle core includes a core compound represented by the following formula 1, and The ligand is bonded to the surface of the nanoparticle core and is represented by the following Formula 2 or Formula 3: Formula 1 THE x THE y Formula 2 Formula 3 In formula 1, A is Zn or Sn, and x and y are each independently an integer selected from 1 to 5, In formula 2, M is one of Li, Na, K, Rb, Cs, Be, Ca, Sr and Ba, R1 is a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms, a is an integer selected from 0 to 3, and and are each a location attached to the nanoparticle core, and In formula 3, R2 is a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group of 2 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms, M is the same as M defined in Formula 2, b is an integer from 0 to 3, and is the location where the nanoparticle core is connected.

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