Ink composition, light-emitting element, and method for manufacturing light-emitting element

Abstract

Provided are an ink composition, a light-emitting element manufactured from the ink composition, and a method of manufacturing the light-emitting element. The ink composition includes a metal oxide and an additive, wherein the ink composition has a viscosity of about 7.5 cp to about 8.0 cp at a temperature of about 25 DEG C. The additive is represented by Chemical Formula 1, which is explained in the specification. [Chemical Formula 1] # imgabs0 #

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority and benefit of Korean Patent Application No. 10 - 2024 - 0013037, filed with the Korean Intellectual Property Office on January 29, 2024, the entire contents of which are incorporated herein by reference. Technical field

[0003] The present disclosure relates to an ink composition having a viscosity within a specific range, a light - emitting element having improved luminous efficiency and element service life, and a method for manufacturing the light - emitting element. Background art

[0004] A light - emitting element converts electrical energy into light energy. Among light - emitting elements, a quantum - dot light - emitting element containing quantum dots in a light - emitting layer has high color purity and high luminous efficiency and can display various colors. In a light - emitting element, holes move to the light - emitting layer via a hole - transport region, and electrons move to the light - emitting layer via an electron - transport region. Current research involves the effective injection and transport of electrons to improve the emission efficiency in quantum - dot light - emitting elements.

[0005] Materials for the electron - transport region having excellent electron - transport properties and stability are being developed to realize a light - emitting element having high luminous efficiency and long service life.

[0006] It should be understood that this background - art section is partly intended to provide a useful background for understanding the technology. However, this background - art section may also include concepts, ideas, or knowledge that were not known or understood by those skilled in the relevant art before the corresponding effective filing date of the subject matter disclosed herein. Summary of the invention

[0007] The present disclosure provides an ink composition capable of improving the light - emitting characteristics and element service life of a light - emitting element.

[0008] The present disclosure also provides a light - emitting element having improved luminous efficiency and element service life.

[0009] The present disclosure also provides a method for manufacturing a light - emitting element having improved luminous efficiency and element service life.

[0010] According to an embodiment, the ink composition may include a metal oxide and an additive represented by Chemical Formula 1, wherein the ink composition may have a viscosity of about 7.5 cP to about 8.0 cP at a temperature of about 25 °C.

[0011] [Chemical Formula 1]

[0012]

[0013] In Chemical Formula 1, X1 and X2 can each independently be a hydroxyl group, a substituted or unsubstituted amine group, or a cyano group; L can be a direct bond or a substituted or unsubstituted methylene group; and R1 and R2 can each independently be a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms.

[0014] In an embodiment, in Chemical Formula 1, R1 can be an unsubstituted methyl group, an unsubstituted ethyl group, an unsubstituted n-propyl group, an unsubstituted n-butyl group, an unsubstituted n-pentyl group, an unsubstituted n-hexyl group, an unsubstituted n-heptyl group, or an unsubstituted n-octyl group.

[0015] In an embodiment, in Chemical Formula 1, R2 can be an unsubstituted methyl group, an unsubstituted ethyl group, or an unsubstituted n-propyl group.

[0016] In an embodiment, in Chemical Formula 1, L can be an unsubstituted methylene group.

[0017] In an embodiment, the volume amount of the additive can be about 7% to about 10% of the total volume of the ink composition.

[0018] In an embodiment, the ink composition can further comprise a solvent for dispersing the metal oxide and the additive.

[0019] In an embodiment, the ink composition can further comprise an organic ligand surrounding the metal oxide.

[0020] In an embodiment, the additive can include at least one compound selected from Compound Group 1.

[0021] [Compound Group 1]

[0022]

[0023] In an embodiment, the metal oxide can include at least one of a first metal oxide represented by Chemical Formula 2 and a second metal oxide represented by Chemical Formula 3.

[0024] [Chemical Formula 2]

[0025] M a O b

[0026] In Chemical Formula 2, M can be Ti, Zr, Sn, W, Ta, Ni, Mo, or Cu; and a and b can each independently be an integer from 1 to 5 (e.g., 1, 2, 3, 4, or 5).

[0027] [Chemical Formula 3]

[0028] Zn (1-c) Q c O

[0029] In Chemical Formula 3, Q may include at least one of Mg, Co, Ni, Zr, Mn, Sn, Y, and Al; and c may be equal to or greater than 0 and less than 0.5 (e.g., 0.1, 0.12, 0.18, 0.2, 0.22, 0.24, 0.27, 0.3, 0.32, 0.35, 0.38, 0.4, 0.42, 0.45, or 0.48).

[0030] In an embodiment, the metal oxide may include the second metal oxide represented by Chemical Formula 3; and in Chemical Formula 3, Q may be Mg, and c may be 0.12.

[0031] According to an embodiment, a light-emitting device may include a first electrode, a first functional layer disposed on the first electrode, a light-emitting layer disposed on the first functional layer, a second functional layer disposed on the light-emitting layer, and a second electrode disposed on the second functional layer, wherein the first functional layer or the second functional layer may include an additive represented by Chemical Formula 1.

[0032] [Chemical Formula 1]

[0033]

[0034] In Chemical Formula 1, X1 and X2 may each independently be a hydroxyl group, a substituted or unsubstituted amine group, or a cyano group; L may be a direct bond or a substituted or unsubstituted methylene group; and R1 and R2 may each independently be a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms.

[0035] In an embodiment, the additive may include at least one compound selected from Compound Group 1 explained herein.

[0036] In an embodiment, the first functional layer may include a hole transport region; the second functional layer may include an electron transport region; and the electron transport region may include the additive.

[0037] In an embodiment, the first functional layer may include an electron transport region; the second functional layer may include a hole transport region; and the electron transport region may include the additive.

[0038] In an embodiment, the second functional layer may include an electron transport layer disposed on the light-emitting layer, and an electron injection layer disposed between the electron transport layer and the second electrode; and the electron transport layer may include the additive.

[0039] In an embodiment, the light-emitting layer may include quantum dots.

[0040] In an embodiment, each of the quantum dots may include a core and a shell surrounding the core.

[0041] According to an embodiment, a method for manufacturing a light-emitting device may include: forming a hole transport region on a first electrode; forming a light-emitting layer on the hole transport region; forming an electron transport region on the light-emitting layer; and forming a second electrode on the electron transport region, wherein

[0042] the forming of the electron transport region may include: forming a preliminary electron transport region by applying an ink composition containing a metal oxide and an additive on the light-emitting layer, and applying heat to the preliminary electron transport region; the ink composition may have a viscosity of about 7.5 cP to about 8.0 cP at a temperature of about 25 °C; and the additive may be represented by Chemical Formula 1.

[0043] [Chemical Formula 1]

[0044]

[0045] In Chemical Formula 1, X1 and X2 may each independently be a hydroxyl group, a substituted or unsubstituted amine group, or a cyano group; L may be a direct bond or a substituted or unsubstituted methylene group; and R1 and R2 may each independently be a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms.

[0046] In an embodiment, the light-emitting layer may include quantum dots.

[0047] In an embodiment, each of the quantum dots may include a core and a shell surrounding the core.

[0048] It should be understood that the above embodiments are described only in a general and explanatory sense and not for the purpose of limitation, and the present disclosure is not limited to the embodiments described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The drawings are included to provide a further understanding of the embodiments and are incorporated into and constitute a part of this specification. The drawings illustrate embodiments of the present disclosure and their principles. By describing the embodiments of the present disclosure in detail with reference to the drawings, the above and other aspects and features of the present disclosure will become more apparent. In the drawings:

[0050] Figure 1 is a schematic perspective view of a display device according to an embodiment;

[0051] Figure 2 is alongFigure 1 A schematic cross-sectional view of a part of a display device taken along the dashed line I-I' in

[0052] Figure 3 is a schematic plan view of a display device according to an embodiment;

[0053] Figure 4 and Figure 5 each is a schematic cross-sectional view of a part of the display device taken along the dashed line II-II' in Figure 3 ;

[0054] Figure 6 is a schematic cross-sectional view of a light-emitting element according to an embodiment;

[0055] Figure 7 and Figure 8 each is a flowchart illustrating a method for manufacturing a light-emitting element according to an embodiment; and

[0056] Figures 9 to 16 each is a schematic cross-sectional view illustrating a part of a method for manufacturing a light-emitting element according to an embodiment. DETAILED DESCRIPTION

[0057] The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. However, the present disclosure may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0058] In the drawings, for ease of description and for clarity, the size, thickness, ratio, and dimensions of elements may be enlarged. The same reference numerals and reference characters refer to the same elements throughout.

[0059] In the specification, it should be understood that when an element (or region, layer, component, etc.) is referred to as being "on", "connected to", or "coupled to" another element, it may be directly on, directly connected to, or directly coupled to the other element, or there may be one or more intervening elements therebetween. In a similar sense, when an element (or region, layer, component, etc.) is described as "covering" another element, it may directly cover the other element, or one or more intervening elements may be present therebetween.

[0060] In the specification, when an element is "directly on", "directly connected to", or "directly coupled to" another element, there is no intervening element. For example, "directly on" can mean that two layers or two elements are provided with no additional element therebetween, such as an adhesive element.

[0061] As used herein, singular forms such as "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0062] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. For example, "A and / or B" can be understood to mean "A, B, or A and B". The terms "and" and "or" can be used in the conjunctive or disjunctive sense and can be understood as equivalent to "and / or".

[0063] In the specification and claims, for purposes of their meaning and interpretation, the term "at least one of..." is intended to include the meaning of "at least one selected from the group consisting of...". For example, "at least one of A, B, and C" can be understood to mean only A, only B, only C, or any combination of two or more of A, B, and C, such as ABC, ACC, BC, or CC. When the term "at least one of..." precedes a list of elements, it modifies the entire list of elements and not a single element of the list.

[0064] It should be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, without departing from the teachings of the present disclosure, a first element may be referred to as a second element. Similarly, without departing from the scope of the present disclosure, a second element may be referred to as a first element.

[0065] For ease of description, spatial relative terms such as "below", "beneath", "under", "above", "on", etc. may be used herein to describe the relationship between one element or component and another element or component as illustrated in the figures. It should be understood that the spatial relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, in the case where the device illustrated in the figures is flipped, a device located "below" or "beneath" another device may be positioned "above" the other device. Thus, the exemplary term "below" can include both a lower position and an upper position. The device may also be oriented in other directions, and thus the spatial relative terms may be interpreted differently depending on the orientation.

[0066] As used herein, the terms "about" or "approximately" include the stated value and mean within an acceptable deviation range of the stated value as determined by one of ordinary skill in the art in view of the relevant measurements and the errors associated with the measurement of that quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ±20%, ±10%, or ±5% of the stated value.

[0067] It is to be understood that the terms "comprises", "comprising", "includes", "including", "have", "having", "contains", "containing", etc. are intended to specify the presence of the stated features, integers, steps, operations, elements, components, or combinations thereof in the present disclosure, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0068] Unless otherwise defined or implied herein, all terms used (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It is to be further understood that terms (such as those defined in common dictionaries) should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly defined in the specification.

[0069] In the specification, the term "substituted or unsubstituted" may describe a group that is substituted or unsubstituted with one or more substituents selected from 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 itself be substituted or unsubstituted. For example, a biphenyl group may be interpreted as an aryl group, or it may be interpreted as a phenyl group substituted with a phenyl group.

[0070] In the specification, the alkyl group can be straight-chain, branched-chain, or cyclic. The number of carbon atoms in the alkyl group can be 1 to 60, 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of the alkyl group can include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, isobutyl group, 2-ethylbutyl group, 3,3-dimethylbutyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, 1-methylpentyl group, 3-methylpentyl group, 2-ethylpentyl group, 4-methyl-2-pentyl group, n-hexyl group, 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, tert-octyl group, 2-ethyloctyl group, 2-butyl octyl group, 2-hexyloctyl group, 3,7-dimethyloctyl group, n-nonyl group, n-decyl group, adamantyl group, 2-ethyldecyl group, 2-butyldecyl group, 2-hexyldecyl group, 2-octyldecyl group, n-undecyl group, n-dodecyl group, 2-ethyldodecyl group, 2-butyldodecyl group, 2-hexyldodecyl group, 2-octyldodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, 2-ethylhexadecyl group, 2-butyldecyl group, 2-hexyldecyl group, 2-octyldecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosyl group, 2-ethyleicosyl group, 2-butyleicosyl group, 2-hexyleicosyl group, 2-octyleicosyl group, n-heneicosyl group, n-docosyl group, n-tricosyl group, n-tetracosyl group, n-pentacosyl group, n-hexacosyl group, n-heptacosyl group, n-octacosyl group, n-nonacosyl group, n-triacontyl group, etc., but the embodiments are not limited thereto.

[0071] In the specification, the alkoxy group can be an oxygen atom bonded to an alkyl group as defined herein. The alkoxy group can be straight-chain, branched-chain, or cyclic. The number of carbon atoms in the alkoxy group is not particularly limited and can be 1 to 30, 1 to 20, 1 to 10, or 1 to 5. Examples of the alkoxy group can include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, nonyloxy group, decyloxy group, etc., but the embodiments are not limited thereto.

[0072] In the specification, the number of carbon atoms in the amine group is not particularly limited and can be 1 to 30, 1 to 20, or 1 to 10. The amine group can be an alkylamine group or an arylamine group. Examples of the amine group can include -NH2, methylamine group, dimethylamine group, phenylamine group, diphenylamine group, naphthylamine group, 9-methyl-anthracenylamine group, etc., but the embodiments are not limited thereto. In the specification, the direct bond can be a single bond.

[0073] Hereinafter, a light-emitting element according to an embodiment and a display device including the light-emitting element will be described with reference to the drawings. Figure 1 is a schematic perspective view of a display device according to an embodiment.

[0074] Reference Figure 1 , the display device DD according to the embodiment can be a device activated in response to an electrical signal. For example, the display device DD can be a large device such as a television, a monitor, or an outdoor advertising board. In an embodiment, the display device DD can be a small device or a medium-sized device (such as a personal computer, a laptop computer, a personal digital terminal, a car navigation unit, a game console, a smart phone, a tablet computer, or a camera). However, these are provided only as examples, and the display device DD can be included in other electronic devices.

[0075] The display device DD can display an image through a display surface DD-IS. The display surface DD-IS can be parallel to a plane defined by a first direction DR1 and a second direction DR2. The display surface DD-IS can include a display area DA and a non-display area NDA.

[0076] Pixels PX can be provided in the display area DA, and pixels PX can not be provided in the non-display area NDA. The non-display area NDA can be defined along the perimeter of the display surface DD-IS. The non-display area NDA can surround the display area DA. However, the embodiments are not limited thereto, and the non-display area NDA can be omitted, or the non-display area NDA can be provided only on one side of the display area DA.

[0077] Figure 1 shows that the display device DD has a flat display surface DD-IS, but the embodiments are not limited thereto. For example, in an embodiment, the display surface DD-IS of the display device DD can be a curved display surface or a three-dimensional display surface. The three-dimensional display surface can include a plurality of display areas provided in different directions.

[0078] In Figure 1In the following drawings, a first direction axis DR1, a second direction axis DR2, and / or a third direction axis DR3 are illustrated. However, the directions represented by the first to third direction axes DR1, DR2, and DR3 described in the specification are relative concepts and can be changed to other directions. The directions represented by the first to third direction axes DR1, DR2, and DR3 can be described as the first to third directions, respectively, and can be represented by the same reference numerals or symbols. In the specification, the first direction axis DR1 and the second direction axis DR2 can be orthogonal to each other, and the third direction axis DR3 can be the normal direction of the plane defined by the first direction axis DR1 and the second direction axis DR2. In the specification, the plan view can refer to the plane defined by the first direction axis DR1 and the second direction axis DR2, and the cross-sectional view can refer to the plane orthogonal to the plane defined by the first direction axis DR1 and the second direction axis DR2 and parallel to the third direction axis DR3. The thickness direction of the display device DD can be the direction parallel to the third direction DR3, which is the normal direction of the plane defined by the first direction DR1 and the second direction DR2.

[0079] In the specification, the upper surface (or front surface) and the lower surface (or rear surface) of the members constituting the display device DD can be defined with respect to the third direction DR3. For example, among the two surfaces facing each other with respect to the third direction DR3, the surface relatively adjacent to the display surface DD-IS can be defined as the front surface (or upper surface), and the surface relatively spaced apart from the display surface DD-IS can be defined as the rear surface (or lower surface). In the specification, the upper part (or upper side) and the lower part (or lower side) can be defined with respect to the third direction DR3, and the upper part (or upper side) can be defined as the part (or side) relatively closer to the display surface DD-IS, and the lower part (or lower side) can be defined as the part (or side) relatively farther from the display surface DD-IS.

[0080] Figure 2 corresponds to Figure 1 a schematic cross-sectional view of a part of the display device DD corresponding to the dashed line I-I' in Figure 2 It can be a schematic cross-sectional view of the display device DD according to an embodiment.

[0081] The display device DD can include a display panel DP and an optical layer PP provided on the display panel DP. The display panel DP can include a substrate layer BS, a circuit layer DP-CL provided on the substrate layer BS, a display element layer DP-EL provided on the circuit layer DP-CL, and a packaging layer TFE provided on the display element layer DP-EL.

[0082] The display panel DP can be a component that generates an image. The display panel DP can be a light-emitting display panel. For example, the display panel DP can be a quantum dot light-emitting display panel including quantum dot light-emitting elements.

[0083] The substrate layer BS can provide a substrate surface on which the circuit layer DP-CL is disposed. The substrate layer BS can be a rigid substrate, or the substrate layer BS can be a flexible substrate that is bendable, foldable, or rollable. The substrate layer BS can be a glass substrate, a metal substrate, a polymer substrate, etc. However, the embodiments are not limited thereto, and the substrate layer BS can include an inorganic layer, an organic layer, or an organic-inorganic composite layer.

[0084] The circuit layer DP-CL can be disposed on the substrate layer BS. The circuit layer DP-CL can include an insulating layer, a semiconductor pattern, a conductive pattern, signal lines, etc. The semiconductor layer and the conductive layer can be formed on the substrate layer BS by being disposed on the insulating layer through methods such as coating and deposition; and the insulating layer, the semiconductor layer, and the conductive layer can be selectively patterned through one or more lithography processes. The semiconductor pattern, the conductive pattern, and the signal lines included in the circuit layer DP-CL can be formed thereby.

[0085] The display element layer DP-EL can be disposed on the circuit layer DP-CL. The display element layer DP-EL can include a pixel definition layer PDL (see Figure 4 and Figure 5 ) and first to third light-emitting elements ED-1, ED-2, and ED-3 (see Figure 4 and Figure 5 ), which will be described later. For example, the display element layer DP-EL can contain 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. For example, the display element layer DP-EL can contain quantum dots.

[0086] The encapsulation layer TFE can protect the display element layer DP-EL from moisture, oxygen, and foreign substances such as dust particles. The encapsulation layer TFE can include at least one inorganic layer. The encapsulation layer TFE can have a structure in which an inorganic layer, an organic layer, and an inorganic layer are stacked in sequence.

[0087] The optical layer PP can be disposed on the display panel DP to control the light reflected by external light at the display panel DP. For example, the optical layer PP can include a polarization layer (not shown) or a color filter layer CFL (see Figure 4 and Figure 5 ). Although not shown in the drawings, in the embodiments, the optical layer PP can be omitted.

[0088] Figure 3is a schematic plan view of a display device DD according to an embodiment. Figure 4 and Figure 5 are each a schematic cross-sectional view of a part of the display device DD corresponding to Figure 3 the dashed line II-II'. Figure 4 and Figure 5 can each be a schematic cross-sectional view of a display device according to an embodiment.

[0089] Referring to Figures 3 to 5 , the display device DD may include a peripheral region NPXA and light-emitting regions PXA-B, PXA-G, and PXA-R. The light-emitting regions PXA-B, PXA-G, and PXA-R may be regions that emit light generated by light-emitting elements ED-1, ED-2, and ED-3, respectively. The light-emitting regions PXA-B, PXA-G, and PXA-R may each have different areas, where the areas may be areas in a plan view.

[0090] According to the colors of the light generated by the light-emitting elements ED-1, ED-2, and ED-3, the light-emitting regions PXA-B, PXA-G, and PXA-R may be arranged in groups. Figures 3 to 5 Illustrated are three light-emitting regions PXA-B, PXA-G, and PXA-R that emit blue light, green light, and red light, respectively. For example, the display device DD may include a blue light-emitting region PXA-B, a green light-emitting region PXA-G, and a red light-emitting region PXA-R that are distinguishable from each other.

[0091] The display panel DP may include a plurality of light-emitting elements ED-1, ED-2, and ED-3 that each emit light having different wavelength regions. The light-emitting elements ED-1, ED-2, and ED-3 may emit light having different colors from each other. For example, the display device DP may include a first light-emitting element ED-1 that emits blue light, a second light-emitting element ED-2 that emits green light, and a third light-emitting element ED-3 that emits red light. However, the embodiment is not limited thereto, and the first to third light-emitting elements ED-1, ED-2, and ED-3 may emit light having the same wavelength region, or at least one light-emitting element may emit light in a different wavelength region from the others.

[0092] In accordance with as Figures 3 to 5In the display device DD of the exemplary embodiment, the light-emitting regions PXA-B, PXA-G, and PXA-R may have regions with different sizes or shapes from each other according to the colors of the light 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 that emits blue light may have the largest area, and the green light-emitting region PXA-G of the second light-emitting element ED-2 that emits green light may have the smallest area. However, the embodiment is not limited thereto, and the light-emitting regions PXA-B, PXA-G, and PXA-R may emit light having a color other than red light, green light, or blue light. In the embodiment, the light-emitting regions PXA-B, PXA-G, and PXA-R may have the same region, or they may have regions provided in different ratios from those Figure 3 illustrated in

[0093] The light-emitting regions PXA-B, PXA-G, and PXA-R may be separated from each other by a pixel defining film PDL. The peripheral region NPXA may be a region between adjacent light-emitting regions PXA-B, PXA-G, and PXA-R, and it may correspond to the pixel defining film PDL. In the embodiment, the light-emitting regions PXA-B, PXA-G, and PXA-R may each correspond to a pixel.

[0094] The pixel defining film PDL may define the light-emitting regions PXA-B, PXA-G, and PXA-R. The light-emitting regions PXA-B, PXA-G, and PXA-R may be separated from the peripheral region NPXA by the pixel defining film PDL.

[0095] The blue light-emitting region PXA-B and the red light-emitting region PXA-R may be alternately arranged along the first direction axis DR1 to form a first group PXG1. The green light-emitting region PXA-G may be arranged along the first direction axis DR1 to form a second group PXG2. The first group PXG1 may be arranged such that it is spaced apart from the second group PXG2 along the second direction axis DR2. The first group PXG1 and the second group PXG2 may be provided in a repeating pattern. The first group PXG1 and the second group PXG2 may be alternately arranged along the second direction axis DR2.

[0096] The red light-emitting region PXA-R may be arranged such that it is spaced apart from the green light-emitting region PXA-G along the fourth direction axis DR4. The blue light-emitting region PXA-B may be arranged such that it is spaced apart from the green light-emitting region PXA-G along the fifth direction axis DR5. The fourth direction axis DR4 may be a direction between the first direction axis DR1 and the second direction axis DR2. The fifth direction axis DR5 may be a direction intersecting the fourth direction axis DR4 or a direction inclined to the second direction axis DR2.

[0097] In an embodiment, the arrangement of the light-emitting regions PXA-B, PXA-G, and PXA-R is not limited to Figure 3 the arrangement shown in. For example, in an embodiment, the red light-emitting region PXA-R, the green light-emitting region PXA-G, and the blue light-emitting region PXA-B may be arranged in this order as a repeating order along the first direction axis DR1. In an embodiment, the shape of each of the light-emitting regions PXA-B, PXA-G, and PXA-R is not limited to Figure 3 the shape shown in, and may be each defined as a shape different from the illustrated shape.

[0098] In the display device DD (e.g., as shown in Figure 4 ), the substrate layer BS may have a single-layer structure or a multi-layer structure. In an embodiment, the substrate layer BS may include a first synthetic resin layer, an intermediate layer having a single-layer structure or a multi-layer structure, and a second synthetic resin layer, and these layers may be stacked in this order. The intermediate layer may be referred to as a substrate barrier layer. The intermediate layer may include a silicon oxide (SiO x ) layer and an amorphous silicon (a-Si) layer provided on the silicon oxide layer, but the embodiment is not limited thereto. 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.

[0099] The first synthetic resin layer and the second synthetic resin layer may each contain a polyimide-based resin. In an embodiment, the first synthetic resin layer and the second synthetic resin layer may each independently contain at least one of an acrylic-based resin, a methacrylate-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 the specification, the term "X-based resin" means a resin containing an "X" functional group.

[0100] The circuit layer DP-CL may be provided on the substrate layer BS, and the circuit layer DP-CL may include transistors (not shown). The transistors (not shown) may each include a control electrode, an input electrode, and an output electrode. For example, the circuit layer DP-CL may include switching transistors and driving transistors for driving the light-emitting elements ED-1, ED-2, and ED-3 of the display element layer DP-EL.

[0101] The display element layer DP-EL may include a pixel defining film PDL and first to third light-emitting elements ED-1, ED-2, and ED-3. An opening OH may be defined in the pixel defining film PDL. The pixel defining film PDL may separate the first to third light-emitting elements ED-1, ED-2, and ED-3. The light-emitting layers EML-B, EML-G, and EML-R of the first to third light-emitting elements ED-1, ED-2, and ED-3 may be respectively disposed in the opening OH defined in the pixel defining film PDL such that they are separated from each other.

[0102] The pixel defining film PDL may be formed of a polymer resin. For example, the pixel defining film PDL may include a polyacrylate-based resin or a polyimide-based resin. In an embodiment, the pixel defining film PDL may further include an inorganic material in addition to the polymer resin. The pixel defining film PDL may include a light-absorbing material, or may include a black pigment or a black dye. The pixel defining film PDL including the black pigment or the black dye may be implemented as a black pixel defining film. When forming the pixel defining film PDL, carbon black or the like may be used as the black pigment or the black dye, but the embodiment is not limited thereto.

[0103] In an embodiment, the pixel defining film PDL may be formed of an inorganic material. For example, the pixel defining film PDL may include an inorganic material such as silicon nitride (SiN x ), silicon oxide (SiO x ), silicon oxynitride (SiO x N y ), etc.

[0104] The light-emitting elements ED-1, ED-2, and ED-3 may each include a first electrode EL1, a first functional layer, a light-emitting layer EML-B, EML-G, or EML-R, a second functional layer, and a second electrode EL2. The first functional layer may be disposed between the first electrode EL1 and the light-emitting layer EML-B, EML-G, or EML-R, and the second functional layer may be disposed between the light-emitting layer EML-B, EML-G, or EML-R and the second electrode EL2.

[0105] In Figure 4In [description], the light-emitting elements ED-1, ED-2, and ED-3 may each include a first electrode EL1, a hole transport region HTR-1, HTR-2, or HTR-3 disposed on the first electrode EL1, a light-emitting layer EML-B, EML-G, or EML-R disposed on the hole transport region HTR-1, HTR-2, or HTR-3, an electron transport region ETR-1, ETR-2, or ETR-3 disposed on the light-emitting layer EML-B, EML-G, or EML-R, and a second electrode EL2 disposed on the electron transport region ETR-1, ETR-2, or ETR-3. The first functional layer may include the hole transport region HTR. For example, the first functional layer may be the hole transport region HTR. The second functional layer may include the electron transport region ETR. For example, the second functional layer may be the electron transport region ETR.

[0106] In Figure 5 [description], the light-emitting elements ED-1, ED-2, and ED-3 may each include a first electrode EL1, an electron transport region ETR-1, ETR-2, or ETR-3 disposed on the first electrode EL1, a light-emitting layer EML-B, EML-G, or EML-R disposed on the electron transport region ETR-1, ETR-2, or ETR-3, a hole transport region HTR-1, HTR-2, or HTR-3 disposed on the light-emitting layer EML-B, EML-G, or EML-R, and a second electrode EL2 disposed on the hole transport region HTR-1, HTR-2, or HTR-3. The first functional layer may include the electron transport region ETR. For example, the first functional layer may be the electron transport region ETR. The second functional layer may include the hole transport region HTR. For example, the second functional layer may be the hole transport region HTR.

[0107] Reference Figure 4 and Figure 5 [description], at least a part of the first electrode EL1 may be exposed in an opening OH defined in a pixel defining film PDL. The first electrode EL1 has a conductive property. The first electrode EL1 may be formed of a metal material, a metal alloy, or a conductive compound. The first electrode EL1 may be a cathode or an anode. However, the embodiments are not limited thereto. In an embodiment, the first electrode EL1 may be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a semi-transmissive reflective electrode, or a reflective electrode. The first electrode EL1 may include at least one of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, Zn, their oxides, their compounds, and their mixtures.

[0108] When the first electrode EL1 is a transmissive electrode, the first electrode EL1 may include a transparent metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc. When the first electrode EL1 is a semi-transmissive reflective electrode or a reflective electrode, the first electrode EL1 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, their compounds or their mixtures (e.g., a mixture of Ag and Mg); or LiF / Ca (a stacked structure of LiF and Ca) or LiF / Al (a stacked structure of LiF and Al). In an embodiment, the first electrode EL1 may have a structure including a reflective film or a semi-transmissive film formed of the materials described above and a transparent conductive film formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc. For example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO, but the embodiment is not limited thereto. In an embodiment, the first electrode EL1 may include a metal material as described above, a combination of at least two metal materials as described above, or an oxide of the metal material as described above. The first electrode EL1 may have a thickness of about to about . For example, the first electrode EL1 may have a thickness of about to about .

[0109] 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, when the first electrode EL1 is an anode, the second electrode EL2 may be a cathode, and when the first electrode EL1 is a cathode, the second electrode EL2 may be an anode. The second electrode EL2 may include at least one of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, W, In, Sn, Zn, their oxides, their compounds, and their mixtures.

[0110] The second electrode EL2 may be a transmissive electrode, a semi-transmissive reflective electrode, or a reflective electrode. When the second electrode EL2 is a transmissive electrode, the second electrode EL2 may be composed of a transparent metal oxide (e.g., indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc.).

[0111] When the second electrode EL2 is a semi-transmissive reflective electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, Yb, W, compounds thereof, or mixtures thereof (e.g., AgMg, AgYb, or MgYb); or LiF / Ca or LiF / Al. In an embodiment, the second electrode EL2 may have a structure including a reflective film or a semi-transmissive film formed of the materials described above and a transparent conductive film formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc. In an embodiment, the second electrode EL2 may include a metal material as described above, a combination of at least two of the metal materials as described above, an oxide of the metal material as described above, etc.

[0112] Although not shown in the drawings, the second electrode EL2 may be electrically connected to an auxiliary electrode. When the second electrode EL2 is electrically connected to the auxiliary electrode, the resistance of the second electrode EL2 can be reduced.

[0113] The light-emitting layers EML-B, EML-G, and EML-R may each be disposed between the first electrode EL1 and the second electrode EL2. The first light-emitting element ED-1 may include a first light-emitting layer EML-B, the second light-emitting element ED-2 may include a second light-emitting layer EML-G, and the third light-emitting element ED-3 may include a third light-emitting layer EML-R. The first light-emitting layer EML-B may include a first quantum dot QD-C1. The second light-emitting layer EML-G may include a second quantum dot QD-C2. The third light-emitting layer EML-R may include a third quantum dot QD-C3.

[0114] The quantum dots QD-C1, QD-C2, and QD-C3 included in the light-emitting layers EML-B, EML-G, and EML-R, respectively, may each be stacked to form at least one layer. Figure 4 and Figure 5 The quantum dots QD-C1, QD-C2, or QD-C3, each having a circular cross-section, are illustrated as being arranged to form approximately two layers, but the embodiment is not limited thereto. For example, the arrangement of the quantum dots QD-C1, QD-C2, and QD-C3 may be changed according to parameters such as the thicknesses of the light-emitting layers EML-B, EML-G, and EML-R, the shapes of the quantum dots QD-C1, QD-C2, and QD-C3 included in the light-emitting layers EML-B, EML-G, and EML-R, and the average diameters of the quantum dots QD-C1, QD-C2, and QD-C3. In an embodiment, in the light-emitting layers EML-B, EML-G, and EML-R, the quantum dots QD-C1, QD-C2, and QD-C3 may be aligned adjacent to each other to form one layer, or may be aligned to form multiple layers, such as two layers or three layers.

[0115] The first quantum dot QD-C1 of the first light-emitting element ED-1 can emit blue light. The second quantum dot QD-C2 of the second light-emitting element ED-2 can emit green light. The third quantum dot QD-C3 of the third light-emitting element ED-3 can emit red light.

[0116] Figure 4 It is illustrated that the first to third quantum dots QD-C1, QD-C2, and QD-C3 have similar diameters to each other, but the embodiments are not limited thereto. In an embodiment, the diameters of the first to third quantum dots QD-C1, QD-C2, and QD-C3 may be different from each other. For example, compared with the average diameter of the second quantum dot QD-C2 of the second light-emitting element ED-2 and the average diameter of the third quantum dot QD-C3 of the third light-emitting element ED-3, which can each emit light in a relatively long wavelength region, the first quantum dot QD-C1 of the first light-emitting element ED-1 that emits light in a relatively short wavelength region may have a smaller average diameter. In the specification, the average diameter may be the arithmetic mean of the particle diameters of the quantum dots. In the specification, the particle diameter of the quantum dot may be the average of the widths of the quantum dot particles measured on its cross-section.

[0117] 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 each be disposed in the opening OH such that they are spaced apart from each other. 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.

[0118] The first to third hole transport regions HTR-1, HTR-2, and HTR-3 may each independently have: a single-layer structure composed of a single layer of a single material, a single-layer structure composed of a single layer containing different materials, or a multi-layer structure including multiple layers containing different materials. In an embodiment, the first to third hole transport regions HTR-1, HTR-2, and HTR-3 may each independently have about to about a thickness. For example, the first to third hole transport regions HTR-1, HTR-2, and HTR-3 may each independently have about to about a thickness. For example, the first to third hole transport regions HTR-1, HTR-2, and HTR-3 may each independently have about to about a thickness.

[0119] The first hole transport region to the third hole transport regions HTR-1, HTR-2, and HTR-3 may each independently further include a hole injection material of the related art and / or a hole transport material of the related art. For example, the first hole transport region to the third hole transport regions HTR-1, HTR-2, and HTR-3 may each independently include a phthalocyanine compound (such as copper phthalocyanine), DNTPD (N1,N1'-([1,1'-biphenyl]-4,4'-diyl)bis(N1-phenyl-N4,N4-dim-tolylbenzene-1,4-diamine)), m-MTDATA (4,4',4”-tris(3-methylphenyl)phenylamino)triphenylamine), 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'-bis(naphthalen-1-yl)-N,N'-diphenyl-benzidine), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium [tetrakis(pentafluorophenyl)borate], HAT-CN (dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile), and the like.

[0120] In an embodiment, the first hole transport region to the third hole transport regions HTR-1, HTR-2, and HTR-3 may each independently include a carbazole-based derivative (such as N-phenylcarbazole or polyvinylcarbazole), a fluorene-based derivative, TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine), a triphenylamine-based derivative, such as TCTA (4,4',4”-tris(N-carbazolyl)triphenylamine), NPB (N,N'-bis(naphthalen-1-yl)-N,N'-diphenyl-benzidine), TAPC (4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)aniline]), 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'-bicarbazole), mCP (1,3-bis(N-carbazolyl)benzene), mDCP (1,3-bis(1,8-dimethyl-9H-carbazol-9-yl)benzene), and the like.

[0121] The electron transport regions ETR-1, ETR-2, and ETR-3 of the first light-emitting element to the third light-emitting elements ED-1, ED-2, and ED-3 may each be disposed in the opening OH such that they are spaced apart from each other. 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.

[0122] The first electron transport region to the third electron transport regions ETR-1, ETR-2, and ETR-3 may each independently have: a single-layer structure composed of a single layer of a single material, a single-layer structure composed of a single layer containing different materials, or a multi-layer structure including multiple layers containing different materials. In an embodiment, the first electron transport region to the third electron transport regions ETR-1, ETR-2, and ETR-3 may each independently have from about to about in thickness.

[0123] The first functional layer or the second functional layer may contain an additive DI (see Figure 6 ). For example, as shown in Figure 4 , the first functional layer may include a first hole transport region to a third hole transport region HTR-1, HTR-2, and HTR-3, the second functional layer may include a first electron transport region to a third electron transport region ETR-1, ETR-2, and ETR-3, and the first hole transport region to the third hole transport region HTR-1, HTR-2, and HTR-3 may contain the additive DI. In the embodiment shown in Figure 4 , the first functional layer may include a first hole transport region to a third hole transport region HTR-1, HTR-2, and HTR-3, the second functional layer may include a first electron transport region to a third electron transport region ETR-1, ETR-2, and ETR-3, and the first electron transport region to the third electron transport region ETR-1, ETR-2, and ETR-3 may contain the additive DI (see Figure 6 ). In the embodiment shown in Figure 5 , the first functional layer may include a first electron transport region to a third electron transport region ETR-1, ETR-2, and ETR-3, the second functional layer may include a first hole transport region to a third hole transport region HTR-1, HTR-2, and HTR-3, and the first hole transport region to the third hole transport region HTR-1, HTR-2, and HTR-3 may contain the additive DI. In Figure 5In the embodiments shown, the first functional layer may include a first electron transport region to a third electron transport region ETR-1, ETR-2, and ETR-3, the second functional layer may include a first hole transport region to a third hole transport region HTR-1, HTR-2, and HTR-3, and the first electron transport region to the third electron transport region ETR-1, ETR-2, and ETR-3 may contain an additive DI. Regarding Figure 6 The description is based on embodiments in which the additive DI (see Figure 6 ) is included in the electron transport region ETR (see Figure 6 ).

[0124] The first electron transport region to the third electron transport region ETR-1, ETR-2, and ETR-3 may each independently further contain an electron injection material of the related art and / or an electron transport material of the related art. For example, the first electron transport region to the third electron transport region ETR-1, ETR-2, and ETR-3 may each contain an anthracene-based compound. In an embodiment, the first electron transport region to the third electron transport region ETR-1, ETR-2, and ETR-3 may each independently contain, for example, Alq3 (tris(8-hydroxyquinolinato)aluminum), 1,3,5-tris[(3-pyridyl)-benzene-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, TPBi (1,3,5-tris(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-quinolinato-N1,O8)-(1,1'-biphenyl-4-yl)aluminum), Bebq2 (bis(benzoquinolinato-10)beryllium), ADN (9,10-di(naphthalen-2-yl)anthracene), BmPyPhB (1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene) or a mixture thereof. In an embodiment, the first electron transport region to the third electron transport region ETR-1, ETR-2, and ETR-3 may each independently 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.

[0125] The encapsulation layer TFE may include at least one inorganic film (hereinafter, the encapsulation inorganic film). In an embodiment, the encapsulation layer TFE may include at least one organic film (hereinafter, the encapsulation organic film) and at least one encapsulation inorganic film.

[0126] The encapsulation inorganic film may protect the display element layer DP-EL from moisture and / or oxygen, and the encapsulation organic film may protect the display element layer DP-EL from foreign substances such as dust particles. The encapsulation inorganic film may include silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, aluminum oxide, etc., but the embodiment is not limited thereto. The encapsulation organic film may include acrylic-based compounds, epoxy-based compounds, etc. The encapsulation organic film may include a photopolymerizable organic material, but the embodiment is not limited thereto.

[0127] The optical layer PP may include a substrate BL and a color filter layer CFL. The substrate BL may provide a substrate surface on which the color filter layer CFL is disposed. The substrate BL may be a glass substrate, a metal substrate, a plastic substrate, etc. However, the embodiment is not limited thereto, and the substrate BL may include an inorganic layer, an organic layer, or an organic-inorganic composite layer.

[0128] The color filter layer CFL may include a first filter to a third filter CF-B, CF-G, and CF-R. The first filter to the third filter CF-B, CF-G, and CF-R may be respectively disposed corresponding to the first light-emitting element to the third light-emitting element ED-1, ED-2, and ED-3. 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 filter to the third filter CF-B, CF-G, and CF-R may be arranged such that they respectively correspond to the light-emitting regions PXA-B, PXA-G, and PXA-R.

[0129] Each of the first filter to the third filter CF-B, CF-G, and CF-R may each include a polymer photosensitive resin and a pigment or a dye. The first filter CF-B may include a blue pigment or a blue dye, the second filter CF-G may include a green pigment or a green dye, and the third filter CF-R may include a red pigment or a red dye. However, the embodiment is not limited thereto, and the first filter CF-B may not include a pigment or a dye. The first filter CF-B may include a polymer photosensitive resin but may not include a pigment or a dye. The first filter CF-B may be transparent. The first filter CF-B may be formed of a transparent photosensitive resin.

[0130] The color filter layer CFL may further include a buffer layer BFL. For example, the buffer layer BFL may serve as a protective layer for protecting the first filter to the third filter CF-B, CF-G, and CF-R. The buffer layer BFL may be an inorganic material layer containing at least one of silicon nitride, silicon oxynitride, and silicon oxide. The buffer layer BFL may be formed of a single layer or multiple layers.

[0131] In an embodiment, the second filter CF-G and the third filter CF-R may each be a yellow filter. The second filter CF-G and the third filter CF-R may not be provided as separate filters and may be provided as an integral filter.

[0132] Although not shown in the drawings, the color filter layer CFL may further include a light-blocking portion (not shown). The light-blocking portion (not shown) may be a black matrix. The light-blocking portion (not shown) may include an organic light-blocking material or an inorganic light-blocking material each including a black pigment or a black dye. The light-blocking portion (not shown) may prevent light leakage and may separate the boundaries between adjacent filters CF-B, CF-G, and CF-R.

[0133] Figure 6 is a schematic cross-sectional view of a light-emitting element ED according to an embodiment. Figure 6 may be an illustration of Figure 4 a schematic cross-sectional view of a part of the light-emitting elements ED-1, ED-2, or ED-3 illustrated in

[0134] Referring to Figure 6 , the light-emitting element ED may include a first electrode EL1, a hole transport region HTR, a light-emitting layer EML, an electron transport region ETR, and a second electrode EL2, which are stacked in that order. The hole transport region HTR may include a hole injection layer HIL and a hole transport layer HTL. The hole injection layer HIL may be disposed on the first electrode EL1, and the hole transport layer HTL may be disposed on the hole injection layer HIL. The electron transport region ETR may include an electron transport layer ETL and an electron injection layer EIL. The electron injection layer EIL may be disposed on the electron transport layer ETL, and the second electrode EL2 may be disposed on the electron injection layer EIL. Although Figure 6 not shown in , in another embodiment, the light-emitting element ED may include a first electrode EL1, an electron transport region ETR, a light-emitting layer EML, a hole transport region HTR, and a second electrode EL2, which are stacked in that order. For example, the electron injection layer EIL may be disposed on the first electrode EL1. For example, the electron transport layer ETL may be disposed on the electron injection layer EIL. For example, the hole injection layer HIL may be disposed on the hole transport layer HTL. For example, the second electrode EL2 may be disposed on the hole injection layer HIL.

[0135] As Figure 6 Figure 6 shows, the quantum dots QD-C can each include a core QD-CO and a shell QD-S surrounding the core. Thus, the quantum dots QD-C can each have a core-shell structure. In an embodiment, the cores QD-CO of the quantum dots QD-C can each include different materials from one another. In another embodiment, the cores QD-CO of the quantum dots QD-C can each include the same material. In yet another embodiment, two cores QD-CO selected from the cores QD-CO of the quantum dots QD-C can each include the same material, and the remaining cores QD-CO can each include different materials from one another.

[0136] In the specification, the quantum dots QD-C can be crystals of a semiconductor compound. The quantum dots QD-C can emit light having various wavelengths according to the size of the crystals. In an embodiment, the quantum dots QD-C can have a diameter of about 1 nm to about 10 nm.

[0137] The quantum dots QD-C can be synthesized by a wet chemical process, a metalorganic chemical vapor deposition process, a molecular beam epitaxy process, or any process similar thereto. The wet chemical process is a method in which an organic solvent and a precursor material are mixed together to grow crystals of quantum dot particles. When the crystals grow, the organic solvent can further serve as a dispersant coordinated to the surface of the quantum dot crystals and can control the growth of the crystals. Accordingly, the wet chemical process can be more easily performed than vapor deposition processes such as a metalorganic chemical vapor deposition (MOCVD) process or a molecular beam epitaxy (MBE) process, and can control the growth of the quantum dot particle crystals by a low-cost process.

[0138] The quantum dots QD-C can include a II-VI group semiconductor compound, a I-II-VI group semiconductor compound, a II-IV-VI group semiconductor compound, a I-II-IV-VI group semiconductor compound, a III-V group semiconductor compound, a III-VI group semiconductor compound, a I-III-VI group semiconductor compound, a IV-VI group semiconductor compound, a II-IV-V group semiconductor compound, a Group IV element or compound, or any combination thereof. In the specification, the term "Group" refers to a group in the IUPAC periodic table.

[0139] Examples of II-VI group semiconductor compounds can include: binary compounds such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe or MgS; ternary compounds such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe or MgZnS; quaternary compounds such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe or HgZnSTe; and any combination thereof. In an embodiment, the II-VI group semiconductor compound can further contain a Group I metal and / or a Group IV element. Examples of I-II-VI group semiconductor compounds can include CuZnS, and examples of II-IV-VI group semiconductor compounds can include ZnSnS, etc. Examples of I-II-IV-VI group semiconductor compounds can include quaternary compounds such as Cu2ZnSnS2, Cu2ZnSnS4, Cu2ZnSnSe4, Ag2ZnSnS2 and any combination thereof.

[0140] Examples of III-V group semiconductor compounds can include: binary compounds such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs or InSb; ternary compounds such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs or InPSb; quaternary compounds such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb; and any combination thereof. In an embodiment, the III-V group semiconductor compound can further contain a Group II element. Examples of III-V group semiconductor compounds further containing a Group II element can include InZnP, InGaZnP, InAlZnP, etc.

[0141] Examples of III-VI group semiconductor compounds can include: binary compounds such as GaS, Ga2S3, GaSe, Ga2Se3, GaTe, InS, InSe, In2Se3 or InTe; ternary compounds such as InGaS3 or InGaSe3; and any combination thereof.

[0142] Examples of I-III-VI group semiconductor compounds can include: ternary compounds such as AgInS, AgInS2, AgInSe2, AgGaS, AgGaS2, AgGaSe2, CuInS, CuInS2, CuInSe2, CuGaS2, CuGaSe2, CuGaO2, AgGaO2 or AgAlO2; quaternary compounds such as AgInGaS2 or AgInGaSe2; and any combination thereof.

[0143] Examples of IV-VI group semiconductor compounds can include: binary compounds such as SnS, SnSe, SnTe, PbS, PbSe or PbTe; ternary compounds such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe or SnPbTe; quaternary compounds such as SnPbSSe, SnPbSeTe or SnPbSTe; and any combination thereof.

[0144] Examples of II-IV-V group semiconductor compounds can include: ternary compounds such as ZnSnP, ZnSnP2, ZnSnAs2, ZnGeP2, ZnGeAs2, CdSnP2, CdGeP2; and any combination thereof.

[0145] Examples of group IV elements or compounds can include: single elements such as Si or Ge; binary compounds such as SiC or SiGe; and any combination thereof.

[0146] Each element contained in a compound (such as a binary compound, ternary compound or quaternary compound) can be present in the particles in a uniform concentration distribution or a non-uniform concentration distribution. For example, the formula can indicate the elements contained in the compound, but the elemental ratio of the compound can vary. For example, AgInGaS2 can represent AgIn x Ga 1-x S2 (where x is a real number from 0 to 1).

[0147] In an embodiment, the quantum dot QD-C can have a single structure in which the concentration of each element contained in the quantum dot QD-C is uniform, or the quantum dot QD-C can have a core-shell structure including a core QD-CO and a shell QD-S. For example, the material contained in the core QD-CO can be different from the material contained in the shell QD-S.

[0148] The shell QD-S of the quantum dot QD-C can be used as a protective layer to prevent chemical denaturation of the core QD-CO to maintain semiconductor properties, and / or can be used as a charging layer to impart electrophoretic properties to the quantum dot QD-C. The shell QD-S can be monolayer or multilayer. The interface between the core QD-CO and the shell QD-S can have a concentration gradient in which the concentration of the element present in the shell QD-S decreases toward the core QD-CO.

[0149] The shell QD-S of the quantum dot QD-C can include a metal oxide, a non-metal oxide, a semiconductor compound, or a combination thereof. Examples of the metal oxide or the non-metal oxide can include: binary compounds such as SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4, or NiO; ternary compounds such as MgAl2O4, CoFe2O4, NiFe2O4, or CoMn2O4; and any combination thereof. Examples of the semiconductor compound can include group II-VI semiconductor compounds, group III-V semiconductor compounds, group III-VI semiconductor compounds, group I-III-VI semiconductor compounds, group IV-VI semiconductor compounds, and any combination thereof as described herein. For example, the semiconductor compound can 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.

[0150] The quantum dot QD-C can have a full width at half maximum (FWHM) of the emission spectrum equal to or less than about 45 nm. For example, the quantum dot QD-C can have an FWHM of the emission spectrum equal to or less than about 40 nm. For example, the quantum dot QD-C can have an FWHM of the emission spectrum equal to or less than about 30 nm. Color purity or color reproducibility can be improved within any of the above ranges. The light emitted by the quantum dot QD-C can be emitted in all directions, such that the optical viewing angle can be improved.

[0151] The form of the quantum dot QD-C is not particularly limited and can be any form used in the relevant field. For example, the quantum dot QD-C can have a spherical shape, a pyramidal shape, a multi-arm shape, or a cubic shape, or the quantum dot QD-C can be in the form of a nanotube, a nanowire, a nanofiber, a nanoplate, etc.

[0152] The band gap of the quantum dot QD-C can be controlled by adjusting the particle size of the quantum dot QD-C or by adjusting the elemental ratio of the compound in the quantum dot QD-C, such that light of various wavelengths can be emitted from the light-emitting layer containing the quantum dot QD-C. Accordingly, a light-emitting element that emits light of various wavelengths can be realized by using quantum dots as described above (which have different sizes of the quantum dot QD-C or different elemental ratios of the compound in the quantum dot QD-C). For example, the size of the quantum dot QD-C or the elemental ratio of the compound in the quantum dot QD-C can be selectively controlled to emit red light, green light, and / or blue light. In an embodiment, the quantum dots can be configured to emit white light through a combination of various colors of light.

[0153] In the light-emitting element ED according to the embodiment, the electron transport region ETR can include a metal oxide IMO and an additive DI. In an embodiment, the electron transport layer ETL in the electron transport region ETR can include a metal oxide IMO and an additive DI.

[0154] According to the embodiment, the additive DI can be represented by Chemical Formula 1:

[0155] [Chemical Formula 1]

[0156]

[0157] In Chemical Formula 1, X1 and X2 can each independently be a hydroxyl group, a substituted or unsubstituted amine group, or a cyano group; L can be a direct bond or a substituted or unsubstituted methylene group; and R1 and R2 can each independently be a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms.

[0158] In an embodiment, X1 and X2 can each independently be a hydroxyl group, an unsubstituted amine group, or a cyano group. For example, X1 and X2 can be the same.

[0159] In an embodiment, R1 can be an unsubstituted methyl group, an unsubstituted ethyl group, an unsubstituted n-propyl group, an unsubstituted n-butyl group, an unsubstituted n-pentyl group, an unsubstituted n-hexyl group, an unsubstituted n-heptyl group, or an unsubstituted n-octyl group. For example, R1 can be an unsubstituted methyl group.

[0160] In an embodiment, R2 can be an unsubstituted methyl group, an unsubstituted ethyl group, or an unsubstituted n-propyl group. For example, R2 can be an unsubstituted ethyl group.

[0161] In an embodiment, L can be an unsubstituted methylene group.

[0162] In an embodiment, additive DI can include at least one compound selected from Compound Group 1:

[0163] [Compound Group 1]

[0164]

[0165] In an embodiment, metal oxide IMO can include at least one of a first metal oxide represented by Chemical Formula 2 and a second metal oxide represented by Chemical Formula 3. In an embodiment, metal oxide IMO can include the second metal oxide represented by Chemical Formula 3.

[0166] [Chemical Formula 2]

[0167] M a O b

[0168] In Chemical Formula 2, M can be Ti, Zr, Sn, W, Ta, Ni, Mo, or Cu; and a and b can each independently be an integer from 1 to 5 (e.g., 1, 2, 3, 4, or 5). For example, a and b can each be 1.

[0169] [Chemical Formula 3]

[0170] Zn (1-c) Q c O

[0171] In Chemical Formula 3, Q can include at least one of Mg, Co, Ni, Zr, Mn, Sn, Y, and Al. In an embodiment, Q can be Mg. In Chemical Formula 3, c can be equal to or greater than 0 and less than 0.5 (e.g., 0.1, 0.12, 0.18, 0.2, 0.22, 0.24, 0.27, 0.3, 0.32, 0.35, 0.38, 0.4, 0.42, 0.45, or 0.48). In an embodiment, c can be 0.12.

[0172] The light-emitting element ED according to an embodiment can improve the in-pixel uniformity (IPU) of the electron transport region ETR by including the metal oxide IMO and the additive DI. For example, the metal oxide IMO and the additive DI can be included in the ink composition IC for forming the electron transport region ETR (see Figure 13In [the context], when forming the electron transport region ETR, the electron transport region ETR has a substantially flat surface. When the electron transport region ETR is formed to have a substantially flat surface and the in-pixel uniformity (IPU) is improved, the contact area between the electron transport region ETR and the light-emitting layer EML and the contact area between the electron transport region ETR and the second electrode EL2 each increase, thereby improving the electron transport efficiency, and thus improving the luminous efficiency and service life of the light-emitting device ED.

[0173] Figure 7 and Figure 8 Each is a flowchart illustrating a method for manufacturing a light-emitting device according to an embodiment. Figure 8 is a flowchart describing the steps of forming an electron transport region according to an embodiment.

[0174] Figures 9 to 16 Each is a schematic cross-sectional view illustrating a part of a method for manufacturing a light-emitting device according to an embodiment.

[0175] Reference Figure 7 , a method for manufacturing a light-emitting device according to an embodiment includes: a step (S100) of forming a hole transport region on a first electrode, a step (S110) of forming a light-emitting layer on the hole transport region, a step (S120) of forming an electron transport region on the light-emitting layer, and a step (S130) of forming a second electrode on the electron transport region. Figure 7 The first electrode, hole transport region, light-emitting layer, electron transport region, and second electrode described in [the context] may be the same as those described for the first electrode EL1, hole transport region HTR, light-emitting layer EML, electron transport region ETR, and second electrode EL2 illustrated in [the context], respectively. Figure 6 in [the context].

[0176] With reference to Figure 7 and Figure 9 , the hole transport region HTR in the step (S100) of forming the hole transport region HTR can be formed using various methods (such as vacuum deposition method, spin coating method, casting method, Langmuir-Blodgett (LB) method, inkjet printing method, laser printing method, or laser-induced thermal imaging (LITI) method). For example, the hole transport region HTR can be formed by the vacuum deposition method.

[0177] With reference to Figure 7 and Figure 10 , the light-emitting layer EML in the step (S110) of forming the light-emitting layer EML can be formed using various methods (such as vacuum deposition method, spin coating method, casting method, Langmuir-Blodgett (LB) method, inkjet printing method, laser printing method, or laser-induced thermal imaging (LITI) method). For example, the light-emitting layer EML can be formed by the inkjet printing method.

[0178] With reference to Figure 7 and Figure 11 , in the step (S120) of forming the electron transport region ETR, the electron transport region ETR can be formed using various methods (such as vacuum deposition method, spin coating method, casting method, Langmuir-Blodgett (LB) method, inkjet printing method, laser printing method, or laser-induced thermal imaging (LITI) method). For example, the electron transport region ETR can be formed by the inkjet printing method.

[0179] With reference to Figure 7 and Figure 12 , in the step (S130) of forming the second electrode EL2, the second electrode EL2 can be formed by physical vapor deposition (PVD), chemical vapor deposition (CVD), or atomic layer deposition (ALD). For example, the second electrode EL2 can be formed by physical vapor deposition (PVD).

[0180] With reference to Figure 7 and Figure 8 , in the method for manufacturing a light-emitting element according to an embodiment, the step (S120) of forming the electron transport region includes a step (S121) of forming a preliminary electron transport region by applying an ink composition containing a metal oxide and an additive on the light-emitting layer, and a step (S122) of applying heat to the preliminary electron transport region. The metal oxide and the additive described in the step (S121) of forming the preliminary electron transport region can be the same as those described for the metal oxide IMO and the additive DI exemplified in Figure 6 .

[0181] See also in conjunction with Figure 8 , Figure 13 and Figure 14 , the ink composition IC in the step (S121) of forming the preliminary electron transport region PETR contains a metal oxide IMO and an additive DI. The ink composition IC may further contain a solvent SL.

[0182] According to an embodiment, the ink composition IC may have a viscosity of about 7.5 cP to about 8.0 cP at a temperature of about 25°C. When the ink composition IC has a viscosity of about 7.5 cP to about 8.0 cP at a temperature of about 25°C, the in-pixel uniformity (IPU) of the electron transport region ETR (see Figure 16 ) derived from the ink composition IC can be improved, such that the contact area between the electron transport region ETR (see Figure 16 ) and the light-emitting layer EML, and the contact area between the electron transport region ETR (see Figure 16 ) and the second electrode EL2 (see Figure 6 ) are increased to improve the electron transport efficiency, thereby improving the light-emitting efficiency and service life of the light-emitting element ED.

[0183] The volume amount of additive DI can be about 7% to about 10% of the total volume of the ink composition IC. When the volume amount of additive DI is about 7% to about 10% of the total volume of the ink composition IC, the ink composition IC can have a viscosity of about 7.5 cP to about 8.0 cP at a temperature of about 25 °C.

[0184] Although not shown in the drawings, in an embodiment, the ink composition can further include a ligand around the metal oxide IMO. For example, the organic ligand can include a dicarboxylic acid, a tricarboxylic acid, a tetracarboxylic acid, or an imidazole-based compound. The organic ligand can surround the metal oxide IMO to improve stability such that the metal oxide IMO is easily dispersed in the solvent SL.

[0185] According to an embodiment, the solvent SL can include a hydrophilic solvent or a hydrophobic solvent. The hydrophilic solvent can include at least one of diethylene glycol tert-butyl ether (DGtBE), triethylene glycol monobutyl ether (TPGBE), and triethylene glycol monoisopropyl ether (TGIPE). The hydrophobic solvent can include at least one of cyclohexylbenzene (CHB) and hexadecane. For example, the solvent SL can include diethylene glycol tert-butyl ether (DGtBE). By dispersing the metal oxide IMO and the additive DI, the solvent SL can contribute to the uniform distribution of the metal oxide IMO and the additive DI in the preliminary electron transport region PETR during the deposition process for forming the preliminary electron transport region PETR (see Figure 13 and Figure 14 ).

[0186] The preliminary electron transport region PETR can be formed using an inkjet printing method. The preliminary electron transport region PETR can be formed by filling an inkjet print head with the ink composition IC (which includes the solvent SL in which the metal oxide IMO and the additive DI are dispersed) and spraying the ink composition IC onto the light-emitting layer EML. The ink composition IC can have a viscosity of about 7.5 cP to about 8.0 cP at a temperature of about 25 °C and thus has excellent impact accuracy. When the viscosity of the ink composition IC is less than about 7.5 cP at a temperature of about 25 °C, the electron transport region ETR cannot be formed to have a substantially flat surface such that the in-pixel uniformity (IPU) cannot be improved. When the viscosity of the ink composition IC is greater than about 8.0 cP at a temperature of about 25 °C, the ink composition IC cannot be easily discharged or cannot be evenly sprayed such that the electron transport region ETR (see Figure 16 ) is not formed to have a substantially flat surface such that the in-pixel uniformity (IPU) cannot be improved.

[0187] See Figure 8 , Figure 15 and Figure 16, when heat is applied to the preliminary electron transport region PETR in the step of applying heat (S122), the solvent SL and the additive DI contained in the preliminary electron transport region PETR can be at least partially vaporized to form the electron transport region ETR. For example, the solvent SL and the additive DI contained in the preliminary electron transport region PETR can be made to form the electron transport region ETR by applying heat to the preliminary electron transport region PETR at a temperature of about 140°C for about 30 minutes.

[0188] Hereinafter, the ink composition according to the embodiment will be described with reference to examples and comparative examples. The examples shown below are provided only to assist in understanding the present disclosure, and the scope of the present disclosure is not limited thereto.

[0189] Table 1 shows the viscosities according to the volume amounts of the additives with respect to the total volume of the ink compositions according to the examples and comparative examples containing metal oxides and different additives. The metal oxide in each of the examples and comparative examples is Zn 0.88 Mg 0.12 O, and a compound from Group 1 of the compounds is used as the additive. The viscosity is measured using a Brookfield viscometer.

[0190] [Table 1]

[0191]

[0192]

[0193] Referring to Table 1, when the volume amount of the additive is about 7% to about 10% relative to the total volume of the ink composition, the viscosity of the ink composition can be about 7.5 cP to 8.0 cP at a temperature of about 25°C. Since the volume of the additive in Examples 1 to 24 is about 7% to about 10% relative to the total volume of the ink composition, the viscosity of the ink composition is about 7.5 cP to about 8.0 cP. The viscosity of Comparative Example 1 without the additive is about 6.2 cP. Comparative Example 2 includes Compound 13 from Compound Group 1 as an additive, but the volume amount of the additive is about 5% relative to the total volume of the ink composition, and thus has a viscosity of 6.1 cP. Comparative Examples 3 and 4 each include Compound 13 from Compound Group 1 as an additive, but have volume amounts of the additive of about 15% and 20% respectively relative to the total volume of the ink composition (each of which is greater than about 10%), and thus have viscosities of 12.2 cP and 15.5 cP respectively. Table 2 below shows the ejection characteristics and in-pixel uniformity (IPU) of the films formed by ejecting the ink compositions of Example 13 and Comparative Examples 1 to 4 in Table 1 above by an inkjet printing method. If the impact accuracy is about -20 μm to about +20 μm, the evaluation criterion for the ejection characteristics is O, if the impact accuracy is not within the above range, the evaluation criterion for the ejection characteristics is X, and a Dimatix Materials Printer DMP-2850 is used as the inkjet printer device.

[0194] [Table 2]

[0195] Emission characteristics In-pixel uniformity (%) Example 13 O 85 Comparative Example 1 O 53 Comparative Example 2 O 51 Comparative Example 3 O 72 Comparative Example 4 X -

[0196] Referring to Table 2 above, Example 13 and Comparative Examples 1 to 3 each have an impact accuracy of about -20 μm to about +20 μm to meet the ejection characteristics, but Comparative Example 4 does not meet the ejection characteristics because it cannot be ejected from the inkjet printer device due to its high viscosity. Compared with Comparative Examples 1 to 3, Example 13 satisfies a viscosity of about 7.5 cP to about 8.0 cP at a temperature of about 25°C to exhibit better in-pixel uniformity (IPU).

[0197] Hereinafter, light-emitting elements according to embodiments will be described with reference to Examples and Comparative Examples. The Examples shown below are provided only to assist in understanding the present disclosure, and the scope of the present disclosure is not limited thereto.

[0198] [Examples]

[0199] 1. Fabrication and Evaluation of Light-Emitting Elements

[0200] (1) Fabrication of Light-Emitting Elements

[0201] Fabricate a light-emitting element according to an embodiment formed from an ink composition according to an embodiment in an electron transport region and a comparative example light-emitting element formed from an ink composition of a comparative example in an electron transport region according to the method described below.

[0202] (Fabrication of Light-Emitting Element)

[0203] After cutting a substrate on which ITO is deposited as an anode into a size of about 50 mm × about 50 mm × about 0.5 mm, and ultrasonically cleaning it with isopropyl alcohol and pure water for about 5 minutes each, the ITO substrate is cleaned by irradiating ultraviolet light for about 30 minutes and exposing it to ozone, and then mounted in a vacuum deposition apparatus.

[0204] Form a hole injection layer HIL of about on the ITO substrate by spin-coating PEDOT / PSS (poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate)), and form a hole transport layer HTL with a thickness of by spin-coating TFB (poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)]).

[0205] Form a light-emitting layer by spin-coating quantum dots having a structure of InP / ZnSe / ZnS on the hole transport layer so as to have a thickness of , and form an electron transport layer with a thickness of by spin-coating the ink composition according to the example and the ink composition of the comparative example on the light-emitting layer. Fabricate a light-emitting element by depositing of AgMg on the electron transport layer to form a cathode.

[0206] (2) Evaluation of Characteristics of Light-Emitting Element

[0207] Evaluate the luminous efficiency (Cd / A, @1280 nits) and element service life (@T90) of the light-emitting elements of Example 13 and the comparative example described above. Table 3 below shows the evaluation results of the light-emitting elements of Example 13 and the comparative example. To evaluate the characteristics of the light-emitting elements fabricated in Example 13 and the comparative example, measure the luminous efficiency (Cd / A) at 1280 nits, and measure the absolute time taken for the luminance to reach 90% of the initial luminance as the element service life (@T90).

[0208] [Table 3]

[0209]

[0210] Referring to Table 3 above, a light-emitting element including an electron transport region derived from the ink composition according to the embodiment has better efficiency and service life. When the viscosity of the ink composition IC is from about 7.5 cP to about 8.0 cP at a temperature of about 25 °C, the in-pixel uniformity (IPU) in the electron transport region derived from the ink composition is improved, such that the contact area between the electron transport region and the light-emitting layer and the contact area between the electron transport region and the second electrode are each increased to improve the electron transport efficiency, thereby improving the luminous efficiency and service life of the light-emitting element.

[0211] The ink composition according to the embodiment can be included in the electron transport region of the light-emitting element to improve the in-pixel uniformity and to contribute to the improvement of the luminous efficiency and service life of the light-emitting element.

[0212] The light-emitting element according to the embodiment can exhibit characteristics of high luminous efficiency and long service life.

[0213] The method for manufacturing the light-emitting element according to the embodiment can provide a manufacturing method for manufacturing a light-emitting element that exhibits high luminous efficiency and long service life.

[0214] Embodiments have been disclosed herein, and although terms are employed, they are used and interpreted in a general and descriptive sense only and not for purposes of limitation. In some instances, as will be apparent to those of ordinary skill in the art, features, characteristics, and / or elements described with respect to one embodiment may be used singly or in combination with those described with respect to other embodiments, unless specifically stated otherwise. Accordingly, those of ordinary skill in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of the present disclosure as set forth in the claims.

Claims

1. An ink composition, comprising: a metal oxide; and an additive represented by Chemical Formula 1, wherein the ink composition has a viscosity of 7.5 cP to 8.0 cP at a temperature of 25 °C: [Chemical Formula 1] Among them, In Chemical Formula 1, X1 and X2 are each independently a hydroxyl group, a substituted or unsubstituted amine group, or a cyano group, L is a direct bond or a substituted or unsubstituted methylene group, and R1 and R2 are each independently a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms.

2. The ink composition according to claim 1, wherein in Chemical Formula 1, R1 is an unsubstituted methyl group, an unsubstituted ethyl group, an unsubstituted n-propyl group, an unsubstituted n-butyl group, an unsubstituted n-pentyl group, an unsubstituted n-hexyl group, an unsubstituted n-heptyl group, or an unsubstituted n-octyl group.

3. The ink composition according to claim 1, wherein in Chemical Formula 1, R2 is an unsubstituted methyl group, an unsubstituted ethyl group, or an unsubstituted n-propyl group.

4. The ink composition according to claim 1, wherein in Chemical Formula 1, L is an unsubstituted methylene group.

5. The ink composition according to claim 1, wherein the volume amount of the additive is 7% to 10% of the total volume of the ink composition.

6. The ink composition according to claim 1, further comprising: a solvent for dispersing the metal oxide and the additive.

7. The ink composition according to claim 1, further comprising: an inorganic ligand surrounding the metal oxide.

8. The ink composition according to claim 1, wherein the additive includes at least one compound selected from Compound Group 1: [Compound Group 1] 9. A light-emitting element, comprising: a first electrode; a first functional layer provided on the first electrode; a light-emitting layer provided on the first functional layer; a second functional layer provided on the light-emitting layer; and a second electrode provided on the second functional layer, wherein the first functional layer or the second functional layer contains an additive represented by Chemical Formula 1: [Chemical Formula 1] wherein, in Chemical Formula 1, X1 and X2 are each independently a hydroxyl group, a substituted or unsubstituted amine group, or a cyano group, L is a direct bond or a substituted or unsubstituted methylene group, and R1 and R2 are each independently a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms.

10. A method for manufacturing a light-emitting element, the method comprising: forming a hole transport region on a first electrode; forming a light-emitting layer on the hole transport region; forming an electron transport region on the light-emitting layer; and forming a second electrode on the electron transport region, wherein the formation of the electron transport region includes: forming a preliminary electron transport region by applying an ink composition containing a metal oxide and an additive on the light-emitting layer, and applying heat to the preliminary electron transport region, the ink composition has a viscosity of 7.5 cP to 8.0 cP at a temperature of 25 °C, and the additive is represented by Chemical Formula 1: [Chemical Formula 1] wherein, in Chemical Formula 1, X1 and X2 are each independently a hydroxyl group, a substituted or unsubstituted amine group, or a cyano group, L is a direct bond or a substituted or unsubstituted methylene group, and R1 and R2 are each independently a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms.

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