Light-emitting element, method for manufacturing the light-emitting element, and display device including the light-emitting element

Abstract

According to one embodiment, the light-emitting device may include a first electrode, an electron transport region, a light-emitting layer, a hole transport region, and a second electrode, which are stacked in sequence. At least one of the electron transport region and the hole transport region may include metal nanoparticles. The metal nanoparticles may include a core including a metal oxide and a ligand bonded to the core, the ligand including at least one of Se and Te. The ligand may be derived from a first compound represented by Chemical Formula 1 or an ion represented by Chemical Formula 2. As a result, the light-emitting device according to one embodiment may be fabricated by an inkjet printing method and may exhibit excellent light efficiency.

Description

[Technical Field]

[0001] The present invention relates to a light-emitting device including quantum dots, a method for manufacturing the light-emitting device, and a display device including the light-emitting device. [Background technology]

[0002] Light-emitting devices are devices that convert electrical energy into light energy. Among light-emitting devices, quantum dot light-emitting devices that contain quantum dots in the light-emitting layer have high color purity, high luminous efficiency, and are capable of multiple colors. In light-emitting devices, holes move to the light-emitting layer via the hole transport region, and electrons move to the light-emitting layer via the electron transport region. In quantum dot light-emitting devices, research is being conducted on smooth injection and transport of holes and electrons to improve light efficiency. Summary of the Invention [Problem to be solved by the invention]

[0003] An object of the present invention is to provide a quantum dot light-emitting device with excellent light efficiency and a display device including the quantum dot light-emitting device.

[0004] Another object of the present invention is to provide a method for manufacturing a light emitting device with excellent manufacturing efficiency. [Means for solving the problem]

[0005] One embodiment provides a light-emitting device including a first electrode, an electron transport region disposed on the first electrode, a light-emitting layer disposed on the electron transport region and including quantum dots, a hole transport region disposed on the light-emitting layer, and a second electrode disposed on the hole transport region, wherein at least one of the electron transport region and the hole transport region comprises metal nanoparticles, the metal nanoparticles comprising a core including a metal oxide and a ligand bonded to the core, the ligand comprising at least one of Se and Te, and derived from a first compound represented by the following Chemical Formula 1 or an ion represented by the following Chemical Formula 2:

[0006] [ka] chemical formula 1

[0007] In Chemical Formula 1, X1 is Se or Te, X2 is a direct bond, Se, or Te, Y1 is a hydrogen atom or a substituted or unsubstituted phenyl group, and if Y1 is a hydrogen atom, X2 is a direct bond, and R1 is a hydrogen atom, a substituted or unsubstituted amine group having from 1 to 10 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having from 1 to 10 carbon atoms.

[0008] [ka] chemical formula 2

[0009] In the above Chemical Formula 2, X3 - Se - or Te - is.

[0010] At least one of Se and Te contained in the ligand may be bound to the surface of the core.

[0011] The ligand can include a head portion attached to the surface and including at least one of Se and Te, and a tail portion attached to the head portion and including a substituted or unsubstituted phenyl group.

[0012] The first compound may be represented by any one of the compounds in a first compound group.

[0013] The metal nanoparticles further include an ancillary ligand attached to the core, and the ancillary ligand can be derived from a second compound including ethylene glycol thiol.

[0014] The second compound may include at least one of poly(ethylene glycol) 2-mercaptoethyl ether acetic acid and thiol-PEG2-acid ((3-(2-(2-mercaptoethoxy)ethoxy)propanoic acid)).

[0015] The metal oxide may include at least one of SnO, SnO2, CuGaO2, Ga2O3, Cu2O, SrCu2O2, SrTiO3, CuAlO2, Ta2O5, NiO, BaSnO3, and TiO2, or may be represented by the following chemical formula M-1. [Chemical formula M-1] Zn q Me (1-q) O In the chemical formula M-1, q is 0 or more and 0.3 or less, and Me is Li, Be, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ga, Ge, Rb, Sr, Zr, Nb, Mo, Ru, Pd, Ag, In, Sn(II), Sn(IV), Sb, or Ba.

[0016] The weight of the organic component in the metal nanoparticles may be 12 wt % or more and 30 wt % or less based on the total weight of the metal nanoparticles.

[0017] The electron transport region may include an electron injection layer disposed on the first electrode, an electron transport layer disposed on the electron injection layer, and a hole blocking layer disposed on the electron transport layer, and at least one of the electron injection layer, the electron transport layer, and the hole blocking layer may include the metal nanoparticles.

[0018] The hole transport region may include an electron blocking layer disposed on the light emitting layer, a hole transport layer disposed on the electron blocking layer, and a hole injection layer disposed on the hole transport layer, and at least one of the electron blocking layer, the hole transport layer, and the hole injection layer may include the metal nanoparticles.

[0019] One embodiment provides a method for manufacturing a light-emitting device, the method comprising the steps of: forming a first electrode on a substrate; forming an electron transport region on the first electrode; providing quantum dots on the electron transport region to form a light-emitting layer; forming a hole transport region on the light-emitting layer; and forming a second electrode on the hole transport region, wherein at least one of the steps of forming the hole transport region and forming the electron transport region comprises providing a composition comprising metal nanoparticles, the metal nanoparticles comprising a core comprising a metal oxide; and a ligand bound to the core, the ligand comprising at least one of Se and Te, and derived from a first compound represented by the following Chemical Formula 1 or an ion represented by the following Chemical Formula 2:

[0020] [ka] chemical formula 1

[0021] In Chemical Formula 1, X1 is Se or Te, X2 is a direct bond, Se, or Te, Y1 is a hydrogen atom or a substituted or unsubstituted phenyl group, and if Y1 is a hydrogen atom, X2 is a direct bond, and R1 is a hydrogen atom, a substituted or unsubstituted amine group having from 1 to 10 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having from 1 to 10 carbon atoms.

[0022] [ka] chemical formula 2

[0023] In the above Chemical Formula 2, X3 - Se - or Te - is.

[0024] The composition can be applied by inkjet printing or dispensing.

[0025] The method for manufacturing the light-emitting device may further include a step of manufacturing the metal nanoparticles before the step of manufacturing the composition, and the step of manufacturing the metal nanoparticles may include a step of preparing preliminary metal nanoparticles including the core and preliminary ligands bonded to the core, and a step of heating a mixture including at least one of the first compound and the ions and the preliminary metal nanoparticles.

[0026] In the step of heating the mixture, the pre-ligands may be removed and the ligands may be bound to the core.

[0027] The mixture may further include at least one of potassium hydroxide, sodium hydroxide, trimethylammonium hydroxide (TMAM), and tetramethylammonium hydroxide (TMAH).

[0028] At least one of Se and Te contained in the ligand may be bound to the surface of the core.

[0029] The metal nanoparticles further include an ancillary ligand attached to the core, and the ancillary ligand can be derived from a second compound including ethylene glycol thiol.

[0030] The metal oxide may include at least one of SnO, SnO2, CuGaO2, Ga2O3, Cu2O, SrCu2O2, SrTiO3, CuAlO2, Ta2O5, NiO, BaSnO3, and TiO2, or may be represented by the following chemical formula M-1. [Chemical formula M-1] Zn q Me (1-q) O In the chemical formula M-1, q is 0 or more and 0.3 or less, and Me is Li, Be, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ga, Ge, Rb, Sr, Zr, Nb, Mo, Ru, Pd, Ag, In, Sn(II), Sn(IV), Sb, or Ba.

[0031] The weight of the organic component in the metal nanoparticles may be 12 wt % or more and 30 wt % or less, based on the total weight of the metal nanoparticles being 100 wt %.

[0032] In one embodiment, there is provided a display device including a circuit layer and a display element layer disposed on the circuit layer, the display element layer including a pixel defining film defining a pixel opening and a light-emitting element, the light-emitting element including a first electrode exposed from the pixel opening, an electron transport region disposed on the first electrode, a light-emitting layer disposed on the electron transport region and including quantum dots, a hole transport region disposed on the light-emitting layer, and a second electrode disposed on the hole transport region, at least one of the electron transport region and the hole transport region includes metal nanoparticles, the metal nanoparticles including a core including a metal oxide and a ligand bound to the core, the ligand including at least one of Se and Te, and derived from a first compound represented by the following Chemical Formula 1 or an ion represented by the following Chemical Formula 2:

[0033] [ka] chemical formula 1

[0034] In Chemical Formula 1, X1 is Se or Te, X2 is a direct bond, Se, or Te, Y1 is a hydrogen atom or a substituted or unsubstituted phenyl group, and if Y1 is a hydrogen atom, X2 is a direct bond, and R1 is a hydrogen atom, a substituted or unsubstituted amine group having from 1 to 10 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having from 1 to 10 carbon atoms.

[0035] [ka] chemical formula 2

[0036] In the above Chemical Formula 2, X3 - Se - or Te - is.

[0037] At least one of Se and Te contained in the ligand may be bound to the surface of the core.

[0038] The metal nanoparticles further include an ancillary ligand attached to the core, and the ancillary ligand can be derived from a second compound including ethylene glycol thiol.

[0039] The metal oxide may include at least one of SnO, SnO2, CuGaO2, Ga2O3, Cu2O, SrCu2O2, SrTiO3, CuAlO2, Ta2O5, NiO, BaSnO3, and TiO2, or may be represented by the following chemical formula M-1. [Chemical formula M-1] Zn q Me (1-q) O In the chemical formula M-1, q is 0 or more and 0.3 or less, and Me is Li, Be, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ga, Ge, Rb, Sr, Zr, Nb, Mo, Ru, Pd, Ag, In, Sn(II), Sn(IV), Sb, or Ba. [Effects of the Invention]

[0040] The light emitting device and the display device including the light emitting device according to an embodiment include metal nanoparticles having ligands bound to their cores, and can exhibit excellent light efficiency.

[0041] According to an embodiment, a method for manufacturing a light-emitting device includes providing a composition containing metal nanoparticles to which ligands are bound, thereby exhibiting excellent manufacturing efficiency. [Brief explanation of the drawings]

[0042] [Figure 1] 1 is a perspective view showing a display device according to an embodiment; [Figure 2] FIG. 2 is a cross-sectional view showing a portion corresponding to II' in FIG. [Figure 3] 1 is a plan view illustrating a display device according to an embodiment. [Figure 4]FIG. 4 is a cross-sectional view showing a portion corresponding to line II-II' in FIG. [Figure 5a] 1 is a cross-sectional view illustrating a light emitting device according to an embodiment. [Figure 5b] 1 is a cross-sectional view illustrating a light emitting device according to an embodiment. [Figure 6a] FIG. 1 illustrates a metal nanoparticle according to one embodiment. [Figure 6b] FIG. 6B shows the XX′ region of FIG. 6a. [Figure 6c] FIG. 1 illustrates a metal nanoparticle according to one embodiment. [Figure 7] 1 is a flowchart illustrating a method for manufacturing a light emitting device according to an embodiment. [Figure 8] 1A to 1C are diagrams schematically illustrating steps for manufacturing a light-emitting device according to an embodiment. [Figure 9] 1A to 1C are diagrams schematically illustrating steps for manufacturing a light-emitting device according to an embodiment. [Figure 10] FIG. 10 is a diagram showing the AA′ region in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0043] Because the present invention can be modified in various ways and can have various forms, specific embodiments are shown by way of example in the drawings and described in detail herein, but it is to be understood that this is not intended to limit the invention to the particular forms disclosed, but rather to include all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.

[0044] As used herein, when a component (or region, layer, portion, etc.) is referred to as being "on" or "coupled" to another component, it means that it may be directly positioned, coupled, or connected to the other component, or that a third component may be disposed therebetween.

[0045] The same reference numerals refer to the same elements. In the drawings, the thickness, proportions, and dimensions of the elements are exaggerated for the purpose of effectively explaining the technical content. "And / or" includes all combinations of one or more elements defined by the associated elements.

[0046] Terms such as "first" and "second" are used to describe various components, but the components are not limited to these terms. These terms are used only to distinguish one component from another. For example, a first component may be designated as a "second component" without departing from the scope of the present invention, and similarly, a second component may be designated as a "first component." A singular expression includes a plural expression unless the context clearly dictates otherwise.

[0047] Furthermore, terms such as "under," "below," "on," and "above" are used to describe the relationship between components shown in the drawings. These terms are relative concepts and are described based on the directions shown in the drawings.

[0048] It should be understood that the terms "comprise" or "have" and the like specify the presence of any feature, number, step, operation, component, part, or combination thereof set forth above in the specification, but do not preclude the presence or possible addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0049] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by a person skilled in the art to which the present invention belongs. Furthermore, terms that are the same as those defined in commonly used dictionaries should be interpreted to have a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted in an overly ideal or formal sense unless explicitly defined herein.

[0050] As used herein, the term "substituted or unsubstituted" may mean substituted or unsubstituted with one or more substituents selected from the group consisting of a deuterium atom, a halogen atom, a cyano group, a nitro group, an amine group, a silyl group, an oxy group, a thio group, a sulfinyl group, a sulfonyl group, a carbonyl group, a boron group, a phosphine oxide group, a phosphine sulfide group, an alkyl group, an alkenyl group, an alkynyl group, a hydrocarbon ring group, an aryl group, and a heterocyclic group. Each of the substituents listed above may be substituted or unsubstituted. For example, a biphenyl group may be interpreted as an aryl group, or as a phenyl group substituted with a phenyl group.

[0051] In this specification, an alkyl group may be straight-chain or branched. The number of carbon atoms in the alkyl group is 1 to 60, 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of alkyl groups include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, a t-butyl group, an i-butyl group, a 2-ethylbutyl group, a 3,3-dimethylbutyl group, an n-pentyl group, an i-pentyl group, a neopentyl group, a t-pentyl group, a 1-methylpentyl group, a 3-methylpentyl group, a 2-ethylpentyl group, a 4-methyl-2-pentyl group, an n-hexyl group, and a 1-methylhexyl group. , 2-ethylhexyl group, 2-butylhexyl group, n-heptyl group, 1-methylheptyl group, 2,2-dimethylheptyl group, 2-ethylheptyl group, 2-butylheptyl group, n-octyl group, t-octyl group, 2-ethyloctyl group, 2-butyloctyl group, 2-hexyloctyl group, 3,7-dimethyloctyl group, n-nonyl group, n-decyl group, adamantyl group, 2-ethyldecyl group, 2-butyldecyl group, 2-heptyl group xyldecyl group, 2-octyldecyl group, n-undecyl group, n-dodecyl group, 2-ethyldodecyl group, 2-butyldodecyl group, 2-hexyldodecyl group, 2-octyldecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, 2-ethylhexadecyl group, 2-butylhexadecyl group, 2-hexylhexadecyl group, 2-octylhexadecyl group, n-heptadecyl group, n- Examples of the alkyl group include, but are not limited to, octadecyl, n-nonadecyl, n-icosyl, 2-ethylicosyl, 2-butylicosyl, 2-hexylicosyl, 2-octylicosyl, n-henicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, and n-triacontyl groups.

[0052] As used herein, the term "alkoxy group" refers to an alkyl group defined above to which an oxygen atom is bonded. The alkoxy group may be linear, branched, or cyclic. The number of carbon atoms in the alkoxy group is not particularly limited, and may be, for example, 1 to 30, 1 to 20, 1 to 10, or 1 to 5. Examples of alkoxy groups include, but are not limited to, ethoxy, n-propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, octyloxy, nonyloxy, and decyloxy.

[0053] In this specification, the number of carbon atoms in 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, but are not limited to, a methylamine group, a dimethylamine group, a phenylamine group, a diphenylamine group, a naphthylamine group, and a 9-methyl-anthracenylamine group.

[0054] As used herein, a direct bond may refer to a single bond.

[0055] BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a display device according to an embodiment of the present invention;

[0056] Referring to FIG. 1 , the display device DD in one 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, monitor, or external billboard. The display device DD may also be a small or medium-sized device such as a personal computer, laptop, personal digital assistant, car navigation unit, game console, smartphone, tablet, or camera. These are merely examples, and the present invention may be applied to other electronic devices without departing from the concept of the present invention.

[0057] The display device DD may display an image IM (or video) via a display surface DD-IS. The display surface DD-IS may be aligned with a plane defined by a first direction DR1 and a second direction DR2. The display surface DD-IS may include a display area DA and a non-display area NDA.

[0058] Pixels PX may be arranged in the display area DA, and pixels PX may not be arranged in the non-display area NDA. 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 embodiment is not limited thereto, and the non-display area NDA may be omitted or may be arranged only on one side of the display area DA.

[0059] Although the display device DD includes a flat display surface DD-IS in FIG. 1, the embodiment is not limited thereto. The display panel DD may include a curved display surface or a stereoscopic display surface. The stereoscopic display surface may include multiple display areas pointing in different directions.

[0060] Although the first to third directional axes DR1 to DR3 are shown in FIG. 1 and the following drawings, the directions indicated by the first to third directional axes DR1, DR2, and DR3 described herein are relative concepts and may be converted into other variations. Furthermore, the directions supported by the first to third directional axes DR1, DR2, and DR3 may be referred to as the first to third directions, and the same reference numerals may be used. In this specification, the first directional axis DR1 and the second directional axis DR2 are perpendicular to each other, and the third directional axis DR3 may be normal to a plane defined by the first directional axis DR1 and the second directional axis DR2. In this specification, a "plane" refers to a plane defined by the first directional axis DR1 and the second directional axis DR2, and a "cross section" refers to a surface perpendicular to the plane defined by the first directional axis DR1 and the second directional axis DR2 and along the third directional axis DR3. The thickness direction of the display device DD may be a direction along the third direction DR3, which is normal to a surface defined by the first direction DR1 and the second direction DR2.

[0061] In this specification, the top surface (or front surface) and bottom surface (or rear surface) of a component constituting the display device DD may be defined based on the third direction DR3. More specifically, of two surfaces of a component facing each other based on the third direction DR3, the surface relatively adjacent to the display surface DD-IS may be defined as the front surface (or top surface), and the surface relatively separated from the display surface DD-IS may be defined as the rear surface (or bottom surface). Also, in this specification, the top (or upper side) and bottom (or lower side) may be defined based on the third direction DR3, with the top (or upper side) being defined as a direction approaching the display surface DD-IS and the bottom (or lower side) being defined as a direction away from the display surface DD-IS.

[0062] As used herein, when a component is "directly disposed / formed on" another component, it means that there is no third component disposed between the two components. In other words, when a component is "directly disposed / formed on" another component, it means that the two components "contact" each other.

[0063] Fig. 2 is a cross-sectional view showing a portion corresponding to line II' in Fig. 1. Fig. 2 may be a cross-sectional view of a display device according to an embodiment.

[0064] The display device DD may include a display panel DP and an optical layer PP disposed on the display panel DP. The display panel DP may include a base layer BS, a circuit layer DP-CL disposed on the base layer BS, a display element layer DP-EL disposed on the circuit layer DP-CL, and a sealing layer TFE covering the display element layer DP-EL.

[0065] The display panel DP may be configured to substantially generate an image. The display panel DP may be an emissive display panel. For example, the display panel DP may be a quantum dot emissive display panel including quantum dot light-emitting elements.

[0066] The base layer BS may be a member that provides a base surface on which the circuit layer DP-CL is disposed. The base layer BS may be a rigid substrate or a flexible substrate that can be bent, folded, rolled, etc. The base layer BS may be a glass substrate, a metal substrate, a polymer substrate, etc. However, the embodiment is not limited thereto, and the base layer BS may be an inorganic layer, an organic layer, or a composite material layer.

[0067] The circuit layer DP-CL may be disposed on the base layer BS. The circuit layer DP-CL may include an insulating layer, a semiconductor pattern, a conductive pattern, and a signal line. After the insulating layer, the semiconductor layer, and the conductive pattern are formed on the base layer BS by coating, deposition, or other methods, the insulating layer, the semiconductor layer, and the conductive pattern may be selectively patterned through multiple photolithography processes. Next, the semiconductor pattern, the conductive pattern, and the signal line included in the circuit layer DP-CL may be formed.

[0068] The display element layer DP-EL may be disposed on the circuit layer DP-CL. The display element layer DP-EL may include a pixel definition layer PDL (described later) and first to third light-emitting elements ED-1, ED-2, and ED-3 (FIG. 4). 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, quantum dots, quantum rods, micro LEDs, or nano LEDs. More specifically, the display element layer DP-EL may include quantum dots.

[0069] The encapsulating layer TFE protects the light-emitting element layer DP-EL from foreign substances such as moisture, oxygen, and dust particles. The encapsulating layer TFE may include at least one inorganic layer. The encapsulating layer TFE may include a structure in which an inorganic layer, an organic layer, and another inorganic layer are sequentially stacked.

[0070] The optical layer PP is disposed on the display panel DP and can control reflected light from the display panel DP due to external light. The optical layer PP can include, for example, a polarizing layer or a color filter layer. However, unlike the illustration, the optical layer PP may be omitted.

[0071] Fig. 3 is a plan view showing a display device of one embodiment. Fig. 4 is a cross-sectional view showing a portion corresponding to line II-II' in Fig. 3. Fig. 3 may be a cross-sectional view showing a display device of one embodiment.

[0072] 3 and 4, the display device DD may include a peripheral region NPXA and light-emitting regions PXA-R, PXA-G, and PXA-B. Each of the light-emitting regions PXA-R, PXA-G, and PXA-B may be an area where light generated from each of the light-emitting elements ED-1, ED-2, and ED-3 is emitted. The areas of the light-emitting regions PXA-R, PXA-G, and PXA-B may be different from each other, and the areas herein may refer to areas on a plane.

[0073] 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 by the light-emitting elements ED-1, ED-2, and ED-3. Figures 3 and 4 exemplarily show three light-emitting regions PXA-R, PXA-G, and PXA-B that emit red, green, and blue lights. For example, a display device DD according to an 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 that are separated from one another.

[0074] 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. The light-emitting elements ED-1, ED-2, and ED-3 may emit light of different colors. For example, the display panel DP may include a light-emitting element ED-1 that emits red light, a second light-emitting element ED-3 that emits green light, and a third light-emitting element ED-3 that emits blue light. However, the embodiment is 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 the light-emitting elements may emit light in a different wavelength region.

[0075] In the display device DD of one embodiment shown in Figures 3 and 4, the light-emitting regions PXA-R, PXA-G, and PXA-B may have different areas depending on the color emitted from the light-emitting 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, which emits blue light, may have the largest area, and the green light-emitting region PXA-G of the second light-emitting element ED-2, which generates green light, may have the smallest area. However, this embodiment is not limited thereto, and the light-emitting regions PXA-R, PXA-G, and PXA-B may emit light of a color other than red, green, and blue. Alternatively, the light-emitting regions PXA-R, PXA-G, and PXA-B may have the same area, or may be provided with area ratios different from those shown in Figure 3.

[0076] Each of the light-emitting regions PXA-R, PXA-G, and PXA-B may be a region separated by a pixel defining layer PPL. The peripheral region NPXA may be a region between adjacent light-emitting regions PXA-R, PXA-G, and PXA-B and may correspond to a pixel (Pixel).

[0077] The pixel defining layer PDL may define the light emitting regions PXA-R, PXA-G, and PXA-B. The light emitting regions PXA-R, PXA-G, and PXA-B may be separated from the peripheral region NPXA by the pixel defining layer PDL.

[0078] The blue light-emitting regions PXA-B and the red light-emitting regions PXA-R may be alternately arranged along the first directional axis DR1 to form a first group PXG1. The green light-emitting regions PXA-G may be arranged along the first directional axis DR1 to form a second group PXG2. The first group PXG1 may be spaced apart from the second group PXG2 along the second directional axis DR2. A plurality of the first group PXG1 and the second group PXG2 may be provided. The first group PXG1 and the second group PXG2 may be alternately arranged along the second directional axis DR2.

[0079] One red light-emitting region PXA-R may be spaced apart from one green light-emitting region PXA-G in the direction of a fourth directional axis DR4. One blue light-emitting region PXA-B may be spaced apart from one green light-emitting region PXA-G in the direction of a fifth directional axis DR5. The direction of the fourth directional axis DR4 may be a direction between the direction of the first directional axis DR1 and the direction of the second directional axis DR2. The fifth directional axis DR5 may intersect the fourth directional axis DR4 and be inclined with respect to the second directional axis DR2.

[0080] On the other hand, the arrangement structure of the light-emitting regions PXA-R, PXA-G, and PXA-B is not limited to the arrangement structure shown in Fig. 3. For example, the light-emitting regions PXA-R, PXA-G, and PXA-B may be arranged such that the red light-emitting region PXA-R, the green light-emitting region PXA-G, and the blue light-emitting region PXA-B are arranged alternately along the first direction axis DR1. Furthermore, on a plane, the shapes of the light-emitting regions PXA-R, PXA-G, and PXA-B are not limited to those shown in the figure, and may be defined as shapes different from those shown in the figure.

[0081] In FIG. 4, the base layer BS may have a single-layer or multi-layer structure. For example, the base layer BS may include a first synthetic resin layer, a multi-layer or single-layer intermediate layer, and a second synthetic resin layer, which are stacked in sequence. The intermediate layer may be referred to as a base barrier layer. The intermediate layer may include, but is not limited to, a silicon oxide (SiOx) layer and an amorphous silicon (a-Si) layer disposed on the silicon oxide layer. For example, the intermediate layer may include at least one of a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer, and an amorphous silicon layer.

[0082] Each of the first and second synthetic resin layers may include a polyimide-based resin. Each of the first and second synthetic resin layers may include at least one of an acrylic-based resin, a methacrylic-based resin, a polyisoprene-based resin, a vinyl-based resin, an epoxy-based resin, a urethane-based resin, a cellulose-based resin, a siloxane-based resin, a polyamide-based resin, and a perylene-based resin. In this specification, "XX-based resin" means that the resin contains a functional group of "XX."

[0083] The circuit layer DP-CL is disposed on the base layer BS, and may include a plurality of transistors (not shown). Each of the transistors (not shown) may include a control electrode, an input electrode, and an output electrode. For example, the circuit layer DP-EL may include a switching transistor and a driving transistor for driving the organic electroluminescent elements ED-1, ED-2, and ED-3.

[0084] 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. The pixel defining layer PDL may have a pixel opening OH defined therein. The pixel defining layer PDL may separate the first to third light emitting elements ED-1, ED-2, and ED-3. The light emitting layers EML-R, EML-G, and EML-B of the first to third light emitting elements ED-1, ED-2, and ED-3 may be disposed in the pixel opening OH defined in the pixel defining layer PDL and separated from each other.

[0085] The pixel defining layer PDL may be made of a polymer resin. For example, the pixel defining layer PDL may be formed to include a polyacrylate-based resin or a polyimide-based resin. The pixel defining layer PDL may also be formed to include an inorganic material in addition to the polymer resin. Meanwhile, the pixel defining layer PDL may be formed to include a light-absorbing material or a black pigment or black dye. A pixel defining layer PDL formed to include a black pigment or black dye implements a black pixel defining layer. When forming the pixel defining layer PDL, carbon black or the like may be used as the black pigment or black dye, but the embodiment is not limited thereto.

[0086] The pixel definition layer PDL may also be made of an inorganic material. For example, the pixel definition layer PDL may be made of silicon nitride (SiN x ), silicon oxide (SiO x ), silicon oxynitride (SiO x N y ) and other inorganic materials.

[0087] Each of the light-emitting elements ED-1, ED-2, and ED-3 may include a hole transport region HTR-1, HTR-2, or HTR-3 disposed on a first electrode EL1, emissive layers EML-B, EML-G, or EML-R disposed on the hole transport regions HTR-1, HTR-2, or HTR-3, electron transport regions ETR-1, ETR-2, or ETR-3 disposed on the emissive layers EML-B, EML-G, or EML-R, and a second electrode EL2 disposed on the electron transport regions ETR-1, ETR-2, or ETR-3.

[0088] The first electrode EL1 may be exposed at the pixel opening OH above the pixel defining layer PDL. The first electrode EL1 has electrical conductivity. The first electrode EL1 may be made of a metal material, a metal alloy, or a conductive compound. The first electrode EL1 may be a cathode or an anode. However, the embodiment is not limited thereto. The first electrode EL1 may also be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a semi-transmissive 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 of two or more selected from these elements, a mixture of two or more selected from these elements, or an oxide thereof.

[0089] If the first electrode EL1 is a transmissive electrode, it may include a transparent metal oxide such as ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), or ITZO (indium tin zinc oxide). If the first electrode EL1 is a semi-transmissive or reflective electrode, it may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca (a laminated structure of LiF and Ca), LiF / Al (a laminated structure of LiF and Al), Mo, Ti, W, or a compound or mixture thereof (e.g., a mixture of Ag and Mg). Alternatively, the first electrode EL1 may have a multi-layer structure including a reflective or semi-transmissive film made of the above materials and a transparent conductive film made of ITO, IZO, ZnO, ITZO, or the like. For example, the first electrode EL1 may have a triple-layer structure of ITO / Ag / ITO, but is not limited thereto. For example, the first electrode EL1 may include, but is not limited to, the above-mentioned metal materials, a combination of two or more metal materials selected from the above-mentioned metal materials, or oxides of the above-mentioned metal materials. The thickness of the first electrode EL1 may be about 700 angstroms to about 10,000 angstroms. For example, the thickness of the first electrode EL1 may be about 1,000 angstroms to about 3,000 angstroms.

[0090] The second electrode EL2 may be a common electrode. The second electrode EL2 may be a cathode or an anode, but the embodiment is not limited thereto. For example, if the first electrode EL1 is an anode, the second electrode may be a cathode, or 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 of two or more selected from these elements, a mixture of two or more selected from these elements, or an oxide thereof.

[0091] The second electrode EL2 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. If the second electrode EL2 is a transmissive electrode, the second electrode EL2 may be made of a transparent metal oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium tin zinc oxide (ITZO).

[0092] If the second electrode EL2 is a semi-transmissive electrode or a reflective electrode, the second electrode EL2 may contain Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, Yb, W, or a compound or mixture containing any of these (e.g., AgMg, AgYb, or MgYb). Alternatively, the second electrode EL2 may have a multi-layer structure including a reflective film or semi-transmissive film made of the above-mentioned material and a transparent conductive film made of ITO, IZO, ZnO, ITZO, or the like. For example, the second electrode EL2 may contain any of the above-mentioned metal materials, a combination of two or more metal materials selected from the above-mentioned metal materials, or oxides of the above-mentioned metal materials.

[0093] Although not shown, the second electrode EL2 may be connected to an auxiliary electrode, which reduces the resistance of the second electrode EL2.

[0094] Emitting layers EML-B, EML-G, and EML-R may be disposed between the first electrode EL1 and the second electrode EL2. The first light-emitting element ED-1 may include a first emitting layer EML-B, the second light-emitting element ED-2 may include a second emitting layer EML-G, and the third light-emitting element ED-3 may include a third emitting layer EML-R. The first emitting layer EML-B may include first quantum dots QD-C1. The second emitting layer EML-G may include second quantum dots QD-C2. The third emitting layer EML-R may include third quantum dots QD-C3.

[0095] The quantum dots QD-C1, QD-C2, and QD-C3 contained in the emitting layers EML-B, EML-G, and EML-R may be stacked to form a layer. While FIG. 4 exemplarily shows the quantum dots QD-C1, QD-C2, and QD-C3, each having a circular cross section, arranged to form roughly two layers, this is not a limitation of the embodiment. For example, the arrangement of the quantum dots QD-C1, QD-C2, and QD-C3 may vary depending on the thickness of the emitting layers EML-B, EML-G, and EML-R, the shape of the quantum dots QD-C1, QD-C2, and QD-C3 contained in the emitting layers EML-B, EML-G, and EML-R, the average diameter of the quantum dots QD-C1, QD-C2, and QD-C3, etc. Specifically, in the light-emitting layers EML-B, EML-G, and EML-R, the quantum dots QD-C1, QD-C2, and QD-C3 can be aligned adjacent to each other to form a single layer, or they can be aligned to form multiple layers, such as two or three layers.

[0096] 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 first quantum dot QD-C3 of the third light-emitting element ED-3 may emit red light. The quantum dots QD-C1, QD-C2, and QD-C3 may each include a core (not shown) and a shell (not shown) surrounding the core. Thus, each of the quantum dots QD-C1, QD-C2, and QD-C3 may have a core-shell structure. The cores of the quantum dots QD-C1, QD-C2, and QD-C3 may contain different materials. Alternatively, the cores of the quantum dots QD-C1, QD-C2, and QD-C3 may contain the same material. Alternatively, two selected cores of the quantum dots QD-C1, QD-C2, and QD-C3 may contain the same material, and the remaining core may contain a different material.

[0097] Although FIG. 4 illustrates the first through fourth quantum dots QD-C1, QD-C2, and QD-C3 as having similar diameters, this is not a limitation. The first through third quantum dots QD-C1, QD-C2, and QD-C3 may also have different diameters. For example, the first quantum dot QD-C1 of the first light-emitting element ED-1, which emits light in a relatively short wavelength region, may have a smaller average diameter than 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, which emit light in a relatively long wavelength region. The average diameter corresponds to the arithmetic average of the diameters of multiple quantum dots. The particle diameter of a quantum dot may be the average width of the quantum dot on a cross section.

[0098] Electron transport regions ETR-1, ETR-2, and ETR-3 may be disposed between the first electrode EL1 and the emissive layers EML-B, EML-G, and EML-R. Electron transport regions ETR-1, ETR-2, and ETR-3 may be disposed between the emissive layers EML-B, EML-G, and EML-R and the second electrode EL2. In one embodiment, at least one of the electron transport regions ETR-1, ETR-2, and ETR-3 and the hole transport regions HTR-1, HTR-2, and HTR-3 may include a metal nanoparticle NP (FIG. 5a) described below. In one embodiment, the metal nanoparticle NP (FIG. 5a) may include a ligand LD and a core MC to which the ligand LD is bound. The ligand LD contains Se (Selenium) and / or Te (Tellurium) bound to a phenyl group. The metal nanoparticle NP (Figure 5a) containing the ligand LD exhibits excellent stability over time and can improve the light efficiency of the emitting layers EML-B, EML-G, and EML-R. The metal nanoparticle NP (Figure 5a) will be described in detail later.

[0099] 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 disposed on and defined by the pixel defining layer 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.

[0100] Each of the hole transport regions HTR-1, HTR-2, and HTR-3 can have a single layer of a single material, a single layer of multiple different materials, or a multilayer structure having multiple layers of multiple different materials. The thickness of each of the first to third hole transport regions HTR-1, HTR-2, and HTR-3 can be, for example, about 50 Å to about 15,000 Å. The thickness of each of the first to third hole transport regions HTR-1, HTR-2, and HTR-3 can be, for example, about 100 Å to about 10,000 Å, for example, about 100 Å to about 5,000 Å.

[0101] The first to third hole transport regions HTR-1, HTR-2, and HTR-3 may further include a known hole injection material and / or a known hole transport material. For example, the first to third hole transport regions HTR-1, HTR-2, and HTR-3 may include a phthalocyanine compound such as copper phthalocyanine, DNTPD(N 1 ,N 1’ -([1,1'-biphenyl]-4,4'-diyl)bis(N 1 -phenyl-N 4 ,N 4 -di-m-tolylbenzene-1,4-diamine)), m-MTDATA (4,4',4''-[tris(3-methylphenyl)phenylamino)triphenylamino]), TDATA (4,4',4''-tris(N,N-diphenylamino)triphenylamine), 2-TNATA (4,4',4''-tris[N(2-naphthyl)-N-phenylamino]-triphenylamine), PEDOT / PSS (poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate), PANI / DBSA (polyaniline / dodecylbenzenesulfonic acid) ), PANI / CSA (polyaniline / camphorsulfonic acid), PANI / PSS ((polyaniline) / poly(4-styrenesulfonate)), NPB (N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine), polyether ketone with triphenylamine (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, HATCN (dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile), and the like.

[0102] The first to third hole transport regions HTR-1, HTR-2, and HTR-3 may be made of a carbazole derivative such as N-phenylcarbazole or poly(vinylcarbazole), a fluorene derivative, a triphenylamine derivative such as TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine) or TCTA (4,4',4''-tris(N-carbazolyl)triphenylamine), NPB (N,N'-di(naphthalen-1-yl)-N,N'-diphenylbenzidine), or TAPC (4,4' -cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine]), HMTPD (4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl), CzSi (9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole), CCP (9-phenyl-9H-3,9'-dicarbazole), mCP (1,3-bis(N-carbazolyl)benzene), or mDCP (1,3-bis(1,8-dimethyl-9H-carbazol-9-yl)benzene).

[0103] 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 disposed and defined by the pixel defining layer 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.

[0104] Each of the first to third electron transport regions ETR-1, ETR-2, and ETR-3 may have a single layer of a single material, a single layer of multiple different materials, or a multilayer structure having multiple layers of multiple different materials.The thickness of each of the first to third electron transport regions ETR-1, ETR-2, and ETR-3 may be, for example, about 1000 Å to about 1500 Å.

[0105] The first to third electron transport regions ETR-1, ETR-2, and ETR-3 may further contain a known electron injection material and / or a known electron transport material. For example, the electron transport region ETR may contain an anthracene-based compound. Alternatively, the first to third electron transport regions ETR-1, ETR-2, and ETR-3 may contain, for example, Alq3 (tris(8-hydroxyquinolinato)aluminum), 1,3,5-tri[(3-pyridyl)-phen-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, or the like. Sen, TPBi (1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen (4,7-diphenyl-1,10-phenanthroline), TAZ (3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), NTAZ (4-(naphthalen-1-yl)-3, 5-diphenyl-4H-1,2,4-triazole), tBu-PBD (2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq (bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-olato)aluminum), Bebq2 (beryllium bis(benzoquinolin-10-olato), ADN (9,10-di(naphthalen-2-yl)anthracene) ), BmPyPhB (1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene), and mixtures thereof. Alternatively, the electron transport region ETR may include BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), TSPO1 (diphenyl(4-(triphenylsilyl)phenyl)phosphine oxide), Bphen (4,7-diphenyl-1,10-phenanthroline), etc.

[0106] The sealing layer TFE may include at least one inorganic film (hereinafter referred to as a sealing inorganic film), or may include at least one organic film (hereinafter referred to as a sealing organic film) and at least one sealing inorganic film.

[0107] The inorganic sealing film can protect the display element layer DP-EL from moisture / oxygen, and the organic sealing film can protect the display element layer DP-EL from foreign matter such as dust particles. The inorganic sealing film can include, but is not limited to, silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, or aluminum oxide. The organic sealing film can include, but is not limited to, an acrylic compound, an epoxy compound, or the like. The organic sealing film can include, but is not limited to, a photopolymerizable organic material.

[0108] The optical layer PP may include a base substrate BL and a color filter layer CFL. The base substrate BL may be a member that provides a base surface on which the color filter layer CFL is disposed. The base substrate BL may be a glass substrate, a metal substrate, a plastic substrate, or the like. However, the embodiment is not limited thereto, and the base substrate BL may be an inorganic layer, an organic layer, or a composite material layer.

[0109] 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 arranged to correspond 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 arranged to correspond to the first to third pixel regions PXA-R, PXA-B, and PXA-G, respectively.

[0110] Each of the first to third filters CF-B, CF-G, and CF-R may include a polymer photosensitive resin and a pigment or dye. The first filter CF-B may include a blue pigment or dye, the second filter CF-G may include a green pigment or dye, and the third filter CF-R may include a red pigment or dye. However, the embodiment is not limited thereto, and the first filter CF-B may not include a pigment or dye. The first filter CF-B may include a polymer photosensitive resin and not include a pigment or dye. The first filter CF-B may be transparent. The first filter CF-B may be made of a transparent photosensitive resin.

[0111] 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 containing at least one inorganic material selected from the group consisting of silicon nitride, silicon oxide, and silicon oxynitride. The buffer layer BFL may be composed of a single layer or multiple layers.

[0112] In addition, 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 integrally without being separated from each other.

[0113] Although not shown, the color filter layer CFL may further include a light-shielding portion (not shown). The light-shielding portion may be a black matrix. The light-shielding portion may be formed using an organic or inorganic light-shielding material containing a black pigment or black dye. The light-shielding portion may prevent light leakage and distinguish the boundaries between adjacent color filters CF-B, CF-G, and CG-R.

[0114] 5a and 5b are cross-sectional views showing light emitting devices ED and ED-a according to an embodiment. At least one of the light emitting devices ED and ED-a described with reference to FIGS. 5a and 5b may be applied to at least one of the first to third light emitting devices ED-1, ED-2, and ED-3 shown in FIG.

[0115] 5a and 5b, the light-emitting element ED, ED-a may include a first electrode EL1, a hole transport region ETR, an emitting layer EML, an electron transport region HTR, and a second electrode EL2, which are stacked in sequence. Referring to FIG. 5a, the hole transport region HTR may include a hole injection layer HIL and a hole transport layer HTL. The hole transport layer HTL may be disposed on the emitting layer EML, and the hole injection layer HIL may be disposed on the hole transport layer HTL. The electron transport region ETR may include an electron transport layer ETL and an electron injection layer EIL. The electron transport layer ETL may be disposed on the electron injection layer EIL, and the emitting layer EML may be disposed on the electron transport layer ETL. In the light-emitting element ED, the electron transport region ETR may include metal nanoparticles NP according to one embodiment.

[0116] Compared to the light-emitting device ED of FIG. 5a, the light-emitting device ED-a of FIG. 5b differs in that the hole-transporting region HTR further includes an electron-blocking layer EBL, and the electron-transporting region ETR further includes a hole-blocking layer HBL. The electron-blocking layer EBL may be disposed between the emitting layer EML and the hole-transporting layer HTL. The hole-blocking layer HBL may be disposed between the emitting layer EML and the electron-transporting layer ETL. In addition, in the light-emitting device ED-a, the hole-transporting region HTR and the electron-transporting region ETR may include metal nanoparticles NP and NP-1 according to an embodiment. However, unlike the illustration, either the electron-blocking layer EBL or the hole-blocking layer HBL may be omitted.

[0117] 5a and 5b, the electron transport region ETR may include the metal nanoparticles NP of an embodiment. More specifically, the electron transport region ETL may include the metal nanoparticles NP of an embodiment. Unlike the illustrations, at least one of the hole blocking layer HBL and the electron injection layer EIL may include the metal nanoparticles NP of an embodiment. Alternatively, the hole blocking layer HBL, the electron transport layer ETL, and the electron injection layer EIL may include the metal nanoparticles NP of an embodiment. The electron transport region ETR including the metal nanoparticles NP of an embodiment may have improved electron injection and / or electron transport properties, which may contribute to improving the light efficiency of the light emitting elements ED and ED-a.

[0118] 5b, the hole transport region HTR may include metal nanoparticles NP-1 according to an embodiment. The metal nanoparticles NP-1 according to an embodiment included in the hole transport region HTR and the metal nanoparticles NP according to an embodiment included in the electron transport region ETR may be the same or different. That is, the material constituting the metal nanoparticles NP-1 according to an embodiment included in the hole transport region HTR and the material constituting the metal nanoparticles NP according to an embodiment included in the electron transport region ETR may be the same or different. The metal nanoparticles NP and NP-1 according to an embodiment will be described in detail later.

[0119] The light-emitting layer EML may include quantum dots QD-C. Hereinafter, the description of the quantum dots QD-C may equally apply to the first to third quantum dots QD-1, QD-2, and QD-3 shown in FIG. 4 .

[0120] As used herein, quantum dots (QD-C) refer to semiconductor compound crystals. Quantum dots (QD-C) can emit light of various wavelengths depending on the size of the crystal. The diameter of quantum dots (QD-C) can be, for example, about 1 nm (nanometer) to 10 nm.

[0121] QD-C quantum dots can be synthesized by wet chemical processes, metalorganic chemical vapor deposition processes, molecular beam epitaxy processes, or similar processes. Wet chemical processes involve mixing an organic solvent with a precursor material and then growing the QD-C particle crystals. As the crystals grow, the organic solvent naturally acts as a dispersant that coordinates with the QD-C crystal surface, regulating the growth of the crystals. Therefore, wet chemical processes are easier and less costly than gas-phase deposition methods such as metalorganic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE). This allows for controlled growth of QD-C quantum dot particles.

[0122] The quantum dots may include II-VI semiconductor compounds; I-II-VI semiconductor compounds; II-IV-VI semiconductor compounds; I-II-IV-VI semiconductor compounds; III-V semiconductor compounds; III-VI semiconductor compounds; I-III-VI semiconductor compounds; IV-VI semiconductor compounds; II-IV-V semiconductor compounds; Group IV elements or compounds; or any combination thereof. As used herein, "Group" refers to a group in the IUPAC periodic table.

[0123] Examples of the II-VI compounds may include binary compounds such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, etc.; ternary compounds such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, etc.; quaternary compounds such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, etc.; or any combination thereof. On the other hand, the II-VI semiconductor compound may further contain a group I metal and / or a group IV element. The group I-II-VI compound may be selected from CuSnS or CuZnS, and the group II-IV-VI compound may be selected from ZnSnS, etc. The group I-II-IV-VI compound may be selected from quaternary compounds selected from the group consisting of CuZnSnS, CuZnSnS, CuZnSnSe, AgZnSnS, and mixtures thereof.

[0124] Examples of the III-V semiconductor compound may include binary compounds such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, etc.; ternary compounds such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, InPSb, etc.; quaternary compounds such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, etc.; or any combination thereof. Meanwhile, the III-V semiconductor compound may further include a group II element. Examples of III-V semiconductor compounds further containing a Group II element may further include InZnP, InGaZnP, InAlZnP, and the like.

[0125] Examples of the III-IV semiconductor compounds may include binary compounds such as GaS, Ga2S3, GaSe, Ga2Se3, GaTe, InS, InSe, In2Se3, InTe, etc.; ternary compounds such as InGaS3, InGaSe3, etc.; or any combination thereof.

[0126] Examples of the I-III-VI semiconductor compounds may include ternary compounds such as AgInS, AgInS2, AgInSe2, AgGaS, AgGaS2, AgGaSe2, CuInS, CuInS2, CuInSe2, CuGaS2, CuGaSe2, CuGaO2, AgGaO2, AgAlO2, etc.; quaternary compounds such as AgInGaS2, AgInGaSe2, etc.; or any combination thereof.

[0127] Examples of the IV-VI semiconductor compounds may include binary compounds such as SnS, SnSe, SnTe, PbS, PbSe, PbTe, etc.; ternary compounds such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, etc.; quaternary compounds such as SnPbSSe, SnPbSeTe, SnPbSTe, etc.; or any combination thereof.

[0128] Examples of the II-IV-V semiconductor compounds may be ternary compounds selected from the group consisting of ZnSnP, ZnSnP2, ZnSnAs2, ZnGeP2, ZnGeAs2, CdSnP2, and CdGeP2, and mixtures thereof.

[0129] The Group IV elements or compounds may include single element compounds such as Si, Ge, etc.; binary compounds such as SiC, SiGe, etc.; or any combination thereof.

[0130] The elements contained in the multi-element compounds such as the binary, ternary, and quaternary compounds may be present in the particles at uniform or non-uniform concentrations. That is, the chemical formula indicates the types of elements contained in the compound, and the ratio of elements within the compound may vary. For example, AgInGaS2 is AgIn x Ga 1-x It can mean S2 (x is a real number between 0 and 1).

[0131] Meanwhile, the quantum dots QD-C may have a single structure in which the concentration of each element contained in the quantum dot QD-C is uniform, or a core-shell dual structure, for example, the material contained in the core and the material contained in the shell may be different from each other.

[0132] The shell of the quantum dot (QD-C) can function as a protective layer to prevent chemical denaturation of the core and maintain its semiconducting properties, and / or as a charging layer to impart electrophoretic properties to the quantum dot. The shell can be a single layer or multiple layers. In the core / shell structure, the concentration of elements present in the shell can have a concentration gradient, decreasing toward the core.

[0133] Examples of the shell of the quantum dot QD-C include metal or nonmetal oxides, semiconductor compounds, or combinations thereof. The metal or nonmetal oxides may include binary compounds such as SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4, NiO, etc., ternary compounds such as MgAl2O4, CoFe2O4, NiFe2O4, CoMn2O4, etc., or any combination thereof. Examples of the semiconductor compounds may include II-VI semiconductor compounds, III-V semiconductor compounds, III-VI semiconductor compounds, III-VI semiconductor compounds, I-III-VI semiconductor compounds, IV-VI semiconductor compounds, or any combination thereof, as described herein. For example, the semiconductor compound may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaS, GaSe, AgGaS, AgGaS2, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or any combination thereof.

[0134] Each element contained in the multi-element compound such as the binary or ternary compound may be present in the particle at a uniform or non-uniform concentration, i.e., the chemical formula indicates the type of elements contained in the compound, and the element ratio within the compound may vary.

[0135] Quantum dots (QD-C) have an emission wavelength spectrum full width at half maximum (FWHM) of about 45 nm or less, preferably about 40 nm or less, and more preferably about 30 nm or less, which improves color purity and color reproducibility. Furthermore, because light emitted through such quantum dots (QD-C) is emitted in all directions, the optical viewing angle can be improved.

[0136] The quantum dots QD-C may be in the form of spherical, pyramidal, multi-arm, or cubic nanoparticles, nanotubes, nanowires, nanofibers, or nanoplate-like particles.

[0137] The energy band gap can be adjusted by adjusting the size of the quantum dots QD-C or the ratio of elements in the compound constituting the quantum dots QD-C, thereby enabling the emission of light in various wavelength bands from the emission layer EML containing the quantum dots QD-C. Therefore, by using quantum dots of different sizes or quantum dots QD-C with different element ratios in the quantum dot compound, a light emitting device ED that emits light of various wavelengths can be realized. Specifically, the size of the quantum dots QD-C or the ratio of elements in the compound constituting the quantum dots QD-C can be adjusted to select red, green, and / or blue light emission. Furthermore, the quantum dots QD-C can be configured to emit white light by combining light of various colors.

[0138] FIG. 6 is a diagram illustrating an embodiment of a metal nanoparticle. The metal nanoparticle NP may include a core MC and a ligand LD bound to the core CM. While eight ligands LD are shown in FIG. 6a, the number of ligands LD is not limited to this. The following description of the embodiment of the metal nanoparticle NP may also be applied to the metal nanoparticles NP and NP-1 shown in FIGS. 5a and 5b.

[0139] The core MC of the metal nanoparticle NP may include a metal oxide, which may include at least one of SnO, SnO2, CuGaO2, Ga2O3, Cu2O, SrCu2O2, SrTiO3, CuAlO2, Ta2O5, NiO, BaSnO3, and TiO2, or may be represented by the following chemical formula M-1: [Chemical formula M-1] Zn q Me (1-q) O In Chemical Formula M-1, q is an integer of 0 to 0.3. Me can be Li, Be, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ga, Ge, Rb, Sr, Zr, Nb, Mo, Ru, Pd, Ag, In, Sn(II), Sn(IV), Sb, or Ba. For example, in Chemical Formula 1, Me can be Mg. That is, in the metal nanoparticle NP, the core MC can include magnesium zinc oxide. However, this is merely an example, and the material contained in the core MC in the metal nanoparticle NP of one embodiment is not limited thereto.

[0140] For example, the ligand LD may include at least one of Se and Te. Conventional metal nanoparticles contain hydroxide ions and have poor stability over time, making them unsuitable for inkjet printing or dispensing. Metal nanoparticles containing hydroxide ions gel when exposed to oxygen and moisture, and aggregation occurs due to the relatively short interparticle distance. As a result, metal nanoparticles containing hydroxide ions are difficult to eject from inkjet printing devices or dispensers. In one embodiment, the metal nanoparticle NP includes a ligand LD including at least one of Se bonded to a phenyl group and Te bonded to a phenyl group, and may exhibit excellent stability over time. In addition, the metal nanoparticle NP may exhibit excellent ejection stability.

[0141] The ligand LD may be derived from a first compound represented by the following Chemical Formula 1. The first compound may include at least one of Se and Te, and Se and Te may be bonded to a phenyl group.

[0142] [ka] chemical formula 1

[0143] In Chemical Formula 1, X1 can be Se or Te. X2 can be a direct bond, Se, or Te. Thus, the first compound represented by Chemical Formula 1 can contain at least one of Se and Te.

[0144] Y1 can be a hydrogen atom or a substituted or unsubstituted phenyl group. If Y1 is a hydrogen atom, X2 can be a direct bond. For example, if Y1 is a hydrogen atom, the ligand LD derived from the first compound represented by Formula 1 can be obtained by removing the hydrogen atom to form X1. - Includes x1 - can be coupled to the core MC. - Se - (Se negative ion) or Te - Alternatively, Y1 may be a substituted or unsubstituted phenyl group, X2 may be a direct bond, and the ligand LD derived from the first compound represented by Chemical Formula 1 may be obtained by removing the substituted or unsubstituted phenyl group to form X1 - Includes x1 - can be bonded to the core MC. In addition, Y1 is a substituted or unsubstituted phenyl group, X2 is Se or Te, and the ligand LD derived from the first compound represented by Chemical Formula 1 is obtained by dissociating the bond between X1 and X2 to form X1. - Ligands containing X2 - X1 - X1 in the ligand containing - is coupled to the core MC, and X2 - X2 in the ligand containing - may be coupled to the core MC, however, this is merely an example and the embodiment is not limited thereto.

[0145] In Chemical Formula 1, R1 can be a hydrogen atom, a substituted or unsubstituted amine group having from 1 to 10 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having from 1 to 10 carbon atoms. For example, R1 can be a hydrogen atom, a methyl group, a methoxy group, or a methylamine group. However, this is merely an example and the embodiment is not limited thereto.

[0146] For example, Chemical Formula 1 is represented by Chemical Formula 1-1 below: Chemical Formula 1-1 specifically shows the position of R1 in Chemical Formula 1.

[0147] [ka] Chemical formula 1-1

[0148] In Chemical Formula 1-1, X1, X2, Y1, and R1 may have the same meaning as in Chemical Formula 1. For example, the first compound may be represented by any one of the compounds in the following first compound group. However, this is merely an example and the embodiment is not limited thereto. [First compound group]

[0149] [ka]

[0150] [ka]

[0151] Alternatively, the ligand LD can be derived from an ion represented by the following chemical formula 2: The ion represented by the chemical formula 2 is Se - and Te - It may include at least one of the following: - and Te - may be attached to a phenyl group.

[0152] [ka] chemical formula 2

[0153] In chemical formula 2, X3 - and Na + The dotted line between X3 and X4 represents an ionic bond. - is Se - or Te - As mentioned above, Se - or Te - A ligand LD comprising:

[0154] In one embodiment, the surface of the metal nanoparticle NP may be modified with a ligand LD. The ligand LD may include a head portion HP that is bonded to the surface of the metal nanoparticle NP and a tail portion TP that is bonded to the head portion HP. In the ligand LD, the head portion HP may be the portion that is directly bonded to the metal nanoparticle NP. The head portion HP may include at least one of Se and Te. More specifically, the head portion HP may include Se. - and Te - The tail portion TP may include a substituted or unsubstituted phenyl group.

[0155] Figure 6b shows the XX' region of Figure 6a. In Figure 6b, the metal oxide constituting the core MC contains at least Zn, and the ligand LD is Se. - and Se - The head part HP of the ligand LD is shown to contain a phenyl group bonded to Se. - Contains Se - is the core MC Zn + The tail portion TP of the ligand LD may include a phenyl group. However, FIG. 6b is merely an example, and the metal oxide constituting the core MC and the material constituting the ligand LD are not limited thereto.

[0156] On the surface of the metal nanoparticle NP, the metal of the metal oxide constituting the core MC is exposed in the form of ions, and a ligand LD can be bound to the metal ions. In metal nanoparticles provided in the hole transport region and the electron transport region, if the metal ions are exposed on the surface without being bound to a ligand, the light efficiency of the light emitting device is reduced. The exposure of metal ions on the surface can be referred to as "surface defects." In other words, surface defects in metal nanoparticles cause a reduction in the light efficiency of the light emitting device. In one embodiment, the metal nanoparticle NP has a ligand LD bound to the metal ions exposed on the surface of the core MC, minimizing the reduction in the high efficiency of the light emitting device ED.

[0157] In one embodiment, the weight percentage of the organic component in the metal nanoparticles NP may be 12 wt% or more and 30 wt% or less, based on the total weight of the metal nanoparticles NP. The organic component is an organic component on the surface of the metal nanoparticles NP. For example, the organic component may include an organic component comprising a phenyl group. If the weight percentage of the organic component in the metal nanoparticles NP is less than 12 wt% based on the total weight of the metal nanoparticles NP, gelation or aggregation of the metal nanoparticles occurs, resulting in reduced stability over time. If the weight percentage of the organic component in the metal nanoparticles NP is more than 30 wt% based on the total weight of the metal nanoparticles NP, the charge injection and transport properties are reduced. Charge refers to holes and electrons. In contrast, metal nanoparticles NPs with a weight percentage of the organic component of 12 wt% or more and 30 wt% or less based on the total weight of the metal nanoparticles NP may maintain stability over time and exhibit excellent charge injection and transport properties. In this specification, the weight of the organic component is measured by thermogravimetric analysis (TGA).

[0158] Figure 6c is a diagram showing a metal nanoparticle NP-a according to another embodiment of the present invention. Compared to the metal nanoparticle NP shown in Figure 6a, the metal nanoparticle NP-a of Figure 6c differs in that it includes an auxiliary ligand LD_S. Hereinafter, in the description of Figure 6c, the same content as that described with reference to Figures 1 to 6b will not be repeated, and the differences will be mainly described.

[0159] In one embodiment, the metal nanoparticle NP-a may further include auxiliary ligands LD_S bound to the core MC. Referring to Figure 6c, the number of auxiliary ligands LD_S may be less than the number of ligands LD. However, this is merely an example and the embodiment is not limited thereto.

[0160] The auxiliary ligand LD_S may include an auxiliary head portion HP_S attached to the core MC and an auxiliary tail portion TP_S attached to the auxiliary head portion HP_S. The auxiliary ligand LD_S may be derived from a second compound including ethylene glycol thiol. Specifically, the auxiliary ligand LD_S may be derived from a second compound including polyethylene glycol thiol. The auxiliary head portion HP_S may be derived from the thiol group of ethylene glycol thiol.

[0161] For example, the second compound may include at least one of poly(ethylene glycol) 2-mercaptoethyl ether acetic acid and thiol-PEG2-acid (3-(2-(2-mercaptoethoxy)ethoxy)propanoic acid). The auxiliary ligand LD_S derived from the second compound containing ethylene glycol thiol may improve the dispersibility of the metal nanoparticles NP-a. In an embodiment of a method for manufacturing a light-emitting device described below, the metal nanoparticles NP may be dispersed in a solvent CV (FIG. 10) to provide a composition COP (FIG. 10). In an embodiment, the metal nanoparticles NP-a may include the auxiliary ligand LD_S and be uniformly dispersed in the solvent CV (FIG. 10).

[0162] The light emitting device ED according to an embodiment may be manufactured by a method for manufacturing a light emitting device according to an embodiment. Figure 7 is a flowchart illustrating a method for manufacturing a light emitting device according to an embodiment. Figures 8 to 10 are diagrams schematically illustrating steps for manufacturing a light emitting device according to an embodiment. In the following description of Figures 7 to 10, overlapping content with that described with reference to Figures 1 to 6c will not be described again, and differences will be mainly described.

[0163] 7, a method for manufacturing a light-emitting device may include step S100 of forming a first electrode, step S200 of forming an electron transport region on the first electrode, step S300 of forming a light-emitting layer on the electron transport region, step S400 of forming a hole transport region on the light-emitting layer, and step S500 of forming a second electrode on the hole transport region. The first electrode EL1 may be disposed on a base layer BS including a substrate. Specifically, the first electrode layer EL1 may be formed on a circuit layer DP-CL (FIG. 9).

[0164] The emissive layer EML can be formed by providing a first composition containing quantum dots QD-C (FIGS. 5a and 5b). The first composition can include the quantum dots QD-C (FIGS. 5a and 5b) and a solvent (not shown) in which the quantum dots QD-C (FIGS. 5a and 5b) are dispersed. For example, the quantum dots QD-C (FIGS. 5a and 5b) can be dispersed in an organic solvent and provided by inkjet printing or dispensing.

[0165] In one embodiment of the method for manufacturing a light-emitting device, at least one of the steps S200 to S400 of forming an electron transport region and forming a hole transport region may include providing a second composition COP (FIG. 9) containing metal nanoparticles NP. Referring to FIG. 8, one embodiment of the method for manufacturing a light-emitting device may include preparing metal nanoparticles NP before providing the second composition COP (FIG. 9).

[0166] Metal nanoparticles NP can be produced from preliminary metal nanoparticles P-NP. The preliminary metal nanoparticles P-NP can include a core MC and a preliminary ligand LD_R bonded to the core CM. The preliminary ligand LD_R can include a preliminary head portion HP_R bonded to the core MC and a preliminary tail portion TP_R bonded to the preliminary head portion HP_R. The preliminary head portion HP_R can include hydroxide ions. In FIG. 8, "step 1" shows a step of producing metal nanoparticles NP. Specifically, "step 1" can represent a step of modifying the surface of the preliminary metal nanoparticles P-NP to produce metal nanoparticles NP.

[0167] A mixture is formed by mixing ethanol, at least one of the first compound and ions, and preliminary metal nanoparticles P-NP, and the mixture is heated to form a ligand LD, which can be bonded to a core MC. As described above, the first compound can be represented by Chemical Formula 1, and the ions can be represented by Chemical Formula 2. As an example, the ligand LD can include at least one of Se and Te.

[0168] When heat is applied to the mixture, a ligand LD may be formed from the first compound or ion, and the ligand LD may be bonded to the core MC. When heat is applied, the bonds constituting the first compound may be dissociated, or a deprotonation reaction may occur in the first compound. During the deprotonation reaction, hydrogen atoms may be removed, as described above. The mixture may further include a substance that promotes the deprotonation reaction. For example, the mixture may further include at least one of potassium hydroxide, sodium hydroxide, trimethylammonium hydroxide (TMAM), and tetramethylammonium hydroxide (TMAH). However, this is merely an example, and the substances contained in the mixture are not limited thereto.

[0169] The preliminary ligand LD_R is removed, and the ligand LD is bonded to the core MC to produce the metal nanoparticle NP. The preliminary ligand LD_R containing hydroxide ions can be removed from the preliminary metal nanoparticle P-NP. The metal nanoparticle NP containing the ligand LD derived from the first compound and / or ion can maintain stability over time and exhibit excellent charge injection and transport properties.

[0170] After the metal nanoparticles NP are produced from the preliminary metal nanoparticles P-NP, a non-polar solvent may be added to precipitate and separate the metal nanoparticles NP. The separated metal nanoparticles NP may be provided in a second composition COP. For example, the non-polar solvent may include at least one of hexane and octane. However, this is merely an example, and the non-polar solvent used to precipitate and separate the metal nanoparticles NP is not limited thereto.

[0171] 9, the second composition COP including the metal nanoparticles NP according to an embodiment may be provided through a nozzle NZ. The second composition COP including the metal nanoparticles NP according to an embodiment may be provided by an inkjet printing method or a dispensing method. As a result, the method for manufacturing a light-emitting device according to an embodiment, which includes providing the second composition COP, may exhibit excellent manufacturing efficiency.

[0172] The metal nanoparticles NP according to one embodiment include at least one of Se bonded to a phenyl group and Te bonded to a phenyl group, and may exhibit characteristics that facilitate ejection from the nozzle NZ. That is, the metal nanoparticles NP according to one embodiment include at least one of Se bonded to a phenyl group and Te bonded to a phenyl group, and may exhibit excellent ejection stability.

[0173] FIG. 10 is an enlarged cross-sectional view of region AA′ in FIG. 9 . FIG. 10 may specifically illustrate a second composition COP including metal nanoparticles NP according to an embodiment. Referring to FIG. 10 , the second composition COP may include metal nanoparticles NP and a solvent CV. The metal nanoparticles NP may be dispersed in the solvent CV. As described above, the metal nanoparticles NP may further include auxiliary ligands LD_S ( FIG. 6c ). This allows the metal nanoparticles NP to be uniformly dispersed in the solvent CV. [Example]

[0174] Table 1 below shows the evaluation results of metal nanoparticles of Comparative Examples and Examples. The metal nanoparticles of Comparative Examples and Examples differ only in the ligand, and the core contains the same metal oxide. The particle size is a measurement of the size of the metal nanoparticles, measured by dynamic light scattering. The weight of the organic component in the metal nanoparticles is measured by thermogravimetric analysis and is shown based on the total weight of the metal nanoparticles. The metal nanoparticles of Comparative Examples contain hydroxide ions as ligands.

[0175] In Table 1, PL_QY (%, defect emission) is the luminous efficiency in the visible light wavelength region that can be caused by surface defects of metal nanoparticles; the larger the PL_QY value, the more surface defects there are. The more surface defects there are in metal nanoparticles, the lower the luminous efficiency of light-emitting devices containing metal nanoparticles in the hole transport region and / or electron transport region. The first excitonic absorption peak is the wavelength at which the highest absorbance is observed in the optical absorption spectrum of metal nanoparticles.

[0176] The first compounds used to form the ligands contained in the metal nanoparticles of the examples are shown below. The metal nanoparticles of Examples 1 to 5 are metal nanoparticles according to one embodiment, and include at least one of Se bonded to a phenyl group and Te bonded to a phenyl group. The Se or Te contained in the first compound is bonded to the surface of the metal nanoparticles. In the following compounds 2, 8, and 10, the bond between Se-Se or Te-Te is dissociated, and Se or Te is bonded to the surface of the metal nanoparticles. (First compound used in the examples)

[0177] [ka]

[0178] [Table 1]

[0179] Referring to Table 1, it can be seen that the metal nanoparticles of Examples 1 to 5 have reduced luminescence due to surface defects compared to the metal nanoparticles of the comparative example. In other words, the metal nanoparticles of Examples 1 to 5 have fewer surface defects, and it is believed that the light-emitting devices including the metal nanoparticles of Examples 1 to 5 exhibit excellent high efficiency.

[0180] The metal nanoparticles of Examples 1 to 5 contain an organic component weight of 12 wt% or more and 30 wt% or less, based on the total weight of the metal nanoparticles. Comparing the results after 0 and 7 days, the metal nanoparticles of Examples 1 to 5 maintain similar particle sizes. In contrast, the metal nanoparticles of the Comparative Example show an increase in particle size of more than four times after 7 days. The increase in particle size over time in the metal nanoparticles of the Comparative Example is due to particle aggregation and gelation. Furthermore, the metal nanoparticles of Comparative Example 1 were found to undergo aggregation and gelation, resulting in a decrease in the transparency of the dispersed solvent. The metal nanoparticles of Examples 1 to 5 exhibit excellent stability over time without particle aggregation and gelation. Therefore, the metal nanoparticles of an embodiment are suitable for application by inkjet printing or dispensing.

[0181] Meanwhile, it can be seen that the metal nanoparticles of Comparative Example 1 and Examples 1 to 5 have similar first excitonic absorption peak values, which confirms that the metal nanoparticles of Comparative Example 1 and Examples 1 to 5 exhibit similar levels of light absorbance.

[0182] A light-emitting device according to an embodiment may include an electron transport region, a light-emitting layer including quantum dots, and a hole transport region. At least one of the electron transport region and the hole transport region may include the metal nanoparticles according to an embodiment, and the metal nanoparticles according to an embodiment may include a core including a metal oxide and a ligand bonded to the core. The ligand may include at least one of Se bonded to a phenyl group and Te bonded to a phenyl group, and may exhibit excellent charge injection and transport properties. As a result, a display device including the light-emitting device according to an embodiment may exhibit excellent light efficiency.

[0183] In addition, according to an embodiment, a method for manufacturing a light-emitting device may include providing a metal oxide having a ligand during at least one of the steps of forming an electron transport region and forming a hole transport region. The ligand may include at least one of Se bonded to a phenyl group and Te bonded to a phenyl group, and may exhibit excellent stability over time and ejection stability. As a result, the metal nanoparticles having the ligand may be provided by an inkjet printing method or a dispensing method.

[0184] Although the present invention has been described above with reference to preferred embodiments, it will be understood by those skilled in the art or those with ordinary knowledge in the art that various modifications and changes can be made to the present invention without departing from the spirit and technical scope of the present invention as set forth in the claims below.

[0185] Therefore, the technical scope of the present invention should be determined by the claims, not by the contents of the detailed description of the specification. [Industrial Applicability]

[0186] INDUSTRIAL APPLICABILITY The present invention provides a light emitting device and a display device including the light emitting device that exhibit excellent efficiency by including metal nanoparticles having ligands bound to the core, and therefore has high industrial applicability.

Claims

1. A first electrode; an electron transport region disposed over the first electrode; a light-emitting layer disposed over the electron transport region and including quantum dots; a hole transport region disposed over the light-emitting layer; a second electrode disposed on the hole transport region, at least one of the electron transport region and the hole transport region comprises metal nanoparticles; The metal nanoparticles are a core comprising a metal oxide; and a ligand bound to the core, the ligand including at least one of Se and Te, and derived from a first compound represented by the following Chemical Formula 1 or an ion represented by the following Chemical Formula 2: 【Chemistry 1】 Chemical formula 1 In the above Chemical Formula 1, X １ is Se or Te, X ２ is a direct linkage, Se, or Te; Y １ is a hydrogen atom or a substituted or unsubstituted phenyl group, Y １ If is a hydrogen atom, then X ２ is a direct bond, R １ is a hydrogen atom, a substituted or unsubstituted amine group having from 1 to 10 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having from 1 to 10 carbon atoms: 【Chemistry 2】 chemical formula 2 In the above Chemical Formula 2, X ３ － Se － or Te － is.

2. The light emitting device according to claim 1 , wherein at least one of Se and Te contained in the ligand is bound to the surface of the core.

3. The light-emitting device of claim 2 , wherein the ligand comprises a head portion bound to the surface and including at least one of Se and Te, and a tail portion bound to the head portion and including a substituted or unsubstituted phenyl group.

4. The light-emitting device according to claim 1 , wherein the first compound is represented by any one of the following compounds of a first compound group: [First compound group] 【Transformation 3】 【change】 。

5. the metal nanoparticle further comprises an ancillary ligand bound to the core; 10. The light-emitting device of claim 1, wherein the ancillary ligand is derived from a second compound comprising ethylene glycol thiol.

6. The second compound is poly(ethylene glycol) 2-mercaptoethyl ether acetic acid, and thiol-PEG ２ 6. The light-emitting device according to claim 5, further comprising at least one of the following: -acid ((3-(2-(2-mercaptoethoxy)ethoxy)propanoic acid)).

7. The metal oxide is SnO, SnO ２ ,CuGaO ２ , Ga ２ O ３ , Cu ２ O, SrCu ２ O ２ , SrTiO ３ , CuAlO ２ , Ta ２ O ５ , NiO, BaSnO ３ , and TiO ２ or the light-emitting device according to claim 1, which is represented by the following chemical formula M-1: [Chemical formula M-1] Zn ｑ Me （１－ｑ） O In the chemical formula M-1, q is equal to or greater than 0 and equal to or less than 0.3; Me is Li, Be, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ga, Ge, Rb, Sr, Zr, Nb, Mo, Ru, Pd, Ag, In, Sn(II), Sn(IV), Sb, or Ba.

8. The light emitting device of claim 1 , wherein the weight of the organic component in the metal nanoparticles is 12 wt % to 30 wt % based on the total weight of the metal nanoparticles.

9. the electron transport region includes an electron injection layer disposed on the first electrode, an electron transport layer disposed on the electron injection layer, and a hole blocking layer disposed on the electron transport layer; The light emitting device of claim 1 , wherein at least one of the electron injection layer, the electron transport layer, and the hole blocking layer includes the metal nanoparticles.

10. the hole transport region includes an electron blocking layer disposed on the light-emitting layer, a hole transport layer disposed on the electron blocking layer, and a hole injection layer disposed on the hole transport layer; The light emitting device of claim 1 , wherein at least one of the electron blocking layer, the hole transport layer, and the hole injection layer includes the metal nanoparticles.

11. forming a first electrode on a substrate; forming an electron transport region over the first electrode; providing quantum dots over the electron transport region to form a light emitting layer; forming a hole transport region over the light-emitting layer; forming a second electrode over the hole transport region; at least one of forming the electron transport region and forming the hole transport region includes providing a composition comprising metal nanoparticles; The metal nanoparticles are a core comprising a metal oxide; and a ligand bound to the core, the ligand including at least one of Se and Te, and derived from a first compound represented by the following Chemical Formula 1 or an ion represented by the following Chemical Formula 2: 【Chemistry 4】 Chemical formula 1 In the above Chemical Formula 1, X １ is Se or Te, X ２ is a direct bond, Se, or Te; Y １ is a hydrogen atom or a substituted or unsubstituted phenyl group, Y １ If is a hydrogen atom, then X ２ is a direct bond, R １ is a hydrogen atom, a substituted or unsubstituted amine group having from 1 to 10 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having from 1 to 10 carbon atoms: 【Transformation 5】 chemical formula 2 In the above Chemical Formula 2, X ３ － Se － or Te － is.

12. The method of claim 11, wherein the composition is applied by inkjet printing or dispensing.

13. further comprising the step of preparing the metal nanoparticles prior to the step of preparing the composition; The step of producing metal nanoparticles includes: providing a preliminary metal nanoparticle comprising the core and a preliminary ligand bound to the core; The method of claim 11 , further comprising: heating a mixture containing at least one of the first compound and the ions and the preliminary metal nanoparticles.

14. The method for manufacturing a light-emitting device according to claim 13 , wherein the step of heating the mixture removes the pre-ligand and bonds the ligand to the core.

15. The method of claim 13, wherein the mixture further comprises at least one of potassium hydroxide, sodium hydroxide, trimethylammonium hydroxide (TMAM), and tetramethylammonium hydroxide (TMAH).

16. The method of claim 11, wherein at least one of Se and Te contained in the ligand is bound to the surface of the core.

17. The method for manufacturing a light-emitting device according to claim 11, wherein the first compound is represented by any one of the following compounds of a first compound group: [First compound group] 【Transformation 6】 【change】 。

18. the metal nanoparticle further comprises an ancillary ligand bound to the core; The method of claim 11 , wherein the auxiliary ligand is derived from a second compound comprising ethylene glycol thiol.

19. The metal oxide is SnO, SnO ２ ,CuGaO ２ , Ga ２ O ３ , Cu ２ O, SrCu ２ O ２ , SrTiO ３ , CuAlO ２ , Ta ２ O ５ , NiO, BaSnO ３ , and TiO ２ The method for manufacturing a light-emitting device according to claim 11, comprising at least one of the following compounds represented by the following chemical formula M-1: [Chemical formula M-1] Zn ｑ Me （１－ｑ） O In the chemical formula M-1, q is equal to or greater than 0 and equal to or less than 0.3; Me is Li, Be, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ga, Ge, Rb, Sr, Zr, Nb, Mo, Ru, Pd, Ag, In, Sn(II), Sn(IV), Sb, or Ba.

20. The method of claim 11, wherein the weight of the organic component in the metal nanoparticles is 12 wt % to 30 wt % based on 100 wt % of the total weight of the metal nanoparticles.

21. a circuit layer; a display element layer disposed on the circuit layer, the display element layer including a pixel defining film in which pixel openings are defined and a light emitting element, The light-emitting element is a first electrode exposed from the pixel opening; an electron transport region disposed over the first electrode; a light-emitting layer disposed over the electron transport region and including quantum dots; a hole transport region disposed over the light-emitting layer; a second electrode disposed over the hole transport region; at least one of the electron transport region and the hole transport region comprises metal nanoparticles; The metal nanoparticles are a core comprising a metal oxide; A display device comprising: a ligand bound to the core, the ligand including at least one of Se and Te, and derived from a first compound represented by the following Chemical Formula 1 or an ion represented by the following Chemical Formula 2: 【Transformation 7】 Chemical formula 1 In the above Chemical Formula 1, X １ is Se or Te, X ２ is a direct bond, Se, or Te; Y １ is a hydrogen atom or a substituted or unsubstituted phenyl group, Y １ If is a hydrogen atom, then X ２ is a direct bond, R １ is a hydrogen atom, a substituted or unsubstituted amine group having from 1 to 10 carbon atoms, a substituted or unsubstituted alkyl group having from 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having from 1 to 10 carbon atoms: 【Transformation 8】 chemical formula 2 In the above Chemical Formula 2, X ３ － Se － or Te － is.

22. The display device according to claim 21 , wherein at least one of Se and Te contained in the ligand is bound to the surface of the core.

23. 22. The display device according to claim 21, wherein the first compound is represented by any one of the compounds of the following first compound group: [First compound group] 【Chemistry 9】 【change】 。

24. the metal nanoparticle further comprises an ancillary ligand bound to the core; 22. The display device of claim 21, wherein the ancillary ligand is derived from a second compound comprising ethylene glycol thiol.

25. The metal oxide is SnO, SnO ２ ,CuGaO ２ , Ga ２ O ３ , Cu ２ O, SrCu ２ O ２ , SrTiO ３ , CuAlO ２ , Ta ２ O ５ , NiO, BaSnO ３ , and TiO ２ or the display device according to claim 21, which contains at least one of the following chemical formula M-1: [Chemical formula M-1] Zn ｑ Me （１－ｑ） O In the chemical formula M-1, q is equal to or greater than 0 and equal to or less than 0.3; Me is Li, Be, Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ga, Ge, Rb, Sr, Zr, Nb, Mo, Ru, Pd, Ag, In, Sn(II), Sn(IV), Sb, or Ba.

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