Quantum dot composition, preparation method of quantum dot composition and display device

Abstract

The invention discloses a quantum dot composition, a preparation method of the quantum dot composition and a display device. A quantum dot composition according to one embodiment of the present invention comprises: a scatterer; a first quantum dot including a first core; a second quantum dot including a second core different from the first core; the first ligand is combined with the surface of the first quantum dot; the second ligand is combined with the surface of the second quantum dot; and a scatterer ligand bonded to the surface of the scatterer, the first ligand and the second ligand being chemically bonded to the scatterer ligand, respectively.

Description

Technical Field

[0001] The present invention relates to a quantum dot composition, a preparation method of the quantum dot composition and a display device. Background Art

[0002] Various display devices are being developed for use in multimedia devices such as televisions, mobile phones, tablet computers, navigation systems, and game consoles. These display devices include display modules that include so-called self-luminous light-emitting elements that emit light from a light-emitting material to create a display.

[0003] Furthermore, to improve the color reproducibility of display devices, different types of light control layers can be included depending on the pixel. These light control layers can transmit only a portion of the wavelength range of the light source or shift the wavelength range. The development of light-emitting devices using quantum dots as a luminescent material is progressing, with demands for improved luminous efficiency and high color characteristics. Summary of the Invention

[0004] An object of the present invention is to provide a quantum dot composition that can exhibit improved luminous efficiency characteristics.

[0005] The object of the present invention is to provide a method for preparing a quantum dot composition with improved process reliability.

[0006] An object of the present invention is to provide a display device comprising a quantum dot complex to improve luminous efficiency.

[0007] According to one embodiment of the present invention, a quantum dot composition includes: a scatterer; a first quantum dot including a first core; a second quantum dot including a second core different from the first core; a first ligand bound to the surface of the first quantum dot; a second ligand bound to the surface of the second quantum dot; and a scatterer ligand bound to the surface of the scatterer, the first ligand and the second ligand being chemically bonded to the scatterer ligand respectively.

[0008] Each of the first quantum dot and the second quantum dot may absorb the first light and emit the second light having a longer wavelength than the first light.

[0009] The maximum emission wavelength range of each of the first quantum dot and the second quantum dot may be greater than or equal to 510 nm and less than or equal to 550 nm.

[0010] It may be that the first core comprises a first semiconductor nanocrystal, the second core comprises a second semiconductor nanocrystal, and each of the first semiconductor nanocrystal and the second semiconductor nanocrystal is selected from II-VI group compounds, III-VI group compounds, I-III-VI group compounds, III-V group compounds, III-II-V group compounds, IV-VI group compounds, IV group elements, IV group compounds and combinations thereof.

[0011] It may be that the first core includes InP, and the second core includes AgInGaS.

[0012] It may be that the first ligand includes: a first head, which is bound to the surface of the first quantum dot; and a first tail, which is separated from the surface of the first quantum dot and chemically bonded to the scatterer ligand, and the second ligand includes: a second head, which is bound to the surface of the second quantum dot; and a second tail, which is separated from the surface of the second quantum dot and bonded to the scatterer ligand.

[0013] Alternatively, the first ligand further includes a first connecting portion connecting the first head portion and the first tail portion, and the second ligand further includes a second connecting portion connecting the second head portion and the second tail portion.

[0014] Alternatively, based on the total weight of the quantum dot composition, the sum of the content of the first quantum dots and the content of the second quantum dots may be greater than or equal to 30 wt % and less than or equal to 38 wt %.

[0015] The content of the scatterer may be greater than or equal to 2 wt % and less than or equal to 8 wt % based on the total weight of the quantum dot composition.

[0016] The scatterer may include: a first scatterer, wherein a first scatterer ligand chemically bonded to the first ligand is bound to a surface; and a second scatterer, wherein a second scatterer ligand chemically bonded to the second ligand is bound to a surface.

[0017] It may be that when the sum of the contents of the first quantum dots, the first ligand, the first scatterer and the first scatterer ligand is defined as a first weight, and the sum of the contents of the second quantum dots, the second ligand, the second scatterer and the second scatterer ligand is defined as a second weight, the ratio of the first weight to the second weight is 1:1 to 2:1.

[0018] It may be that the first quantum dot further includes a first shell covering the first core, the second quantum dot further includes a second shell covering the second core, the first ligand is bound to the surface of the first shell, and the second ligand is bound to the surface of the second shell.

[0019] According to one embodiment of the present invention, a display device includes: a display panel; and a light conversion layer, which is arranged on the display panel and includes a plurality of light control parts, at least one of the plurality of light control parts includes a quantum dot complex, and the quantum dot complex includes: a scatterer; a first quantum dot, including a first core; a second quantum dot, including a second core different from the first core; a first ligand, which is bound to the surface of the first quantum dot; a second ligand, which is bound to the surface of the second quantum dot; and a scatterer ligand, which is bound to the surface of the scatterer, and the first ligand and the second ligand are chemically bonded to the scatterer ligand respectively.

[0020] The display panel may include: a light emitting element that generates first light; the light conversion layer may include: a first light control unit that transmits the first light; a second light control unit that converts the first light into second light; and a third light control unit that converts the first light into third light.

[0021] The blue light absorption rate of the light control portion including the quantum dot complex among the plurality of light control portions may be 90% or higher.

[0022] When the light control portion including the quantum dot complex is irradiated with excitation light having a wavelength of 450 nm, the external quantum efficiency (EQE) may be 35% or higher.

[0023] According to one embodiment of the present invention, a method for preparing a quantum dot composition includes: providing a first quantum dot having a first ligand bound to its surface and comprising a first core, and a second quantum dot having a second ligand bound to its surface and comprising a second core different from the first core; providing a scatterer having a scatterer ligand bound to its surface; mixing the first quantum dot bound to the first ligand and the second quantum dot bound to the second ligand with the scatterer bound to the scatterer ligand to provide a prepared quantum dot composition; and providing heat or light to the prepared quantum dot composition to chemically bond the scatterer ligand to each of the first ligand and the second ligand.

[0024] The scatterer ligand may include: a first functional group chemically bonded to the first ligand and the second ligand, wherein the first functional group includes at least one of a thiol group, an amine group, a hydroxyl group, an azide group, and an oxetane group.

[0025] It may be that the first ligand includes: a second functional group, which forms a chemical bond with the first functional group; the second ligand includes: a third functional group, which forms a chemical bond with the first functional group; the second functional group and the third functional group independently include at least one of an alkenyl group, an alkynyl group, a carboxyl group, an acyl halide group and a (meth)acrylate group.

[0026] It may be that the step of providing the prepared quantum dot composition and the step of chemically bonding the scatterer ligand to each of the first ligand and the second ligand include: the step of mixing the first quantum dots bound to the first ligand with the scatterer bound to the scatterer ligand to provide a first prepared quantum dot composition; the step of mixing the second quantum dots bound to the second ligand with the scatterer bound to the scatterer ligand to provide a second prepared quantum dot composition; the step of providing heat or light to the first prepared quantum dot composition and the second prepared quantum dot composition; and the step of mixing the first prepared quantum dot composition and the second prepared quantum dot composition to which heat or light has been provided.

[0027] According to an embodiment of the present invention, a quantum dot composition that can exhibit high quantum efficiency can be provided.

[0028] According to an embodiment of the present invention, a display device including quantum dots exhibiting high quantum efficiency and exhibiting improved luminous efficiency characteristics can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a three-dimensional diagram of an electronic device according to an embodiment of the present invention.

[0030] Figure 2 It is an exploded perspective view of an electronic device according to an embodiment of the present invention.

[0031] Figure 3 is with Figure 1 The II' line corresponds to a cross-sectional view of a display device according to an embodiment of the present invention.

[0032] Figure 4 FIG. 1 is an enlarged plan view showing a portion of a display device according to an embodiment of the present invention.

[0033] Figure 5 is a cross-sectional view of a display device according to an embodiment of the present invention.

[0034] Figure 6a as well as Figure 6b FIG. 1 is a diagram schematically showing the structure of a quantum dot according to an embodiment of the present invention.

[0035] Figure 7 Graphs showing absorption and emission spectra of a light conversion pattern including a single quantum dot and a light conversion pattern including two types of quantum dots.

[0036] Figure 8 is a cross-sectional view of a display device according to an embodiment of the present invention.

[0037] Figure 9ais a cross-sectional view of a display device according to an embodiment of the present invention.

[0038] Figure 9b is a cross-sectional view of a light-emitting element according to an embodiment of the present invention.

[0039] Figure 10 1 is a sequence diagram illustrating a method for preparing a quantum dot composition according to an embodiment of the present invention.

[0040] Figure 11 、 Figure 12a as well as Figure 12b 1 is a diagram illustrating some steps in a method for preparing a quantum dot composition according to an embodiment of the present invention.

[0041] Figure 13 1 is a sequence diagram illustrating a method for preparing a quantum dot composition according to an embodiment of the present invention.

[0042] Figure 14a as well as Figure 14b 1 is a diagram illustrating some steps in a method for preparing a quantum dot composition according to an embodiment of the present invention.

[0043] Figure 15a FIG. 1 is a flowchart illustrating a method for manufacturing a display device according to an embodiment of the present invention.

[0044] Figure 15b FIG. 1 is a sequence diagram for subdividing the steps of forming a light control layer according to an embodiment of the present invention.

[0045] Figures 16a to 16c 1 is a cross-sectional view illustrating a portion of steps in a method for manufacturing a display device according to an embodiment of the present invention.

[0046] (Explanation of Reference Numerals)

[0047] DD: Display device ED: Light-emitting element

[0048] CCL: Light conversion layer CCP-B, CCP-G, CCP-R: Light control unit

[0049] QD1: first quantum dot QD2: second quantum dot

[0050] LD1: first ligand LD2: second ligand

[0051] SP: Scatterer S-LD: Scatterer Ligand DETAILED DESCRIPTION

[0052] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0053] In this specification, when any component (or region, layer, part, etc.) is mentioned as being "on", "connected" or "combined" to other components, it means that it can be directly connected / combined to other components or a third component can be arranged between them.

[0054] The same reference numerals refer to the same components. In addition, in the drawings, the thickness, proportions, and sizes of the components are exaggerated for the purpose of effectively explaining the technical content. "And / or" includes all combinations of more than one possible combination of the related structures.

[0055] Terms such as "first" and "second" can be used to describe various constituent elements, but these constituent elements are not limited by these terms. These terms are used solely to distinguish one constituent element from other constituent elements. For example, without departing from the scope of the present invention, the first constituent element can be named the second constituent element, and similarly, the second constituent element can be named the first constituent element. Unless the context clearly indicates otherwise, a singular expression includes a plural expression.

[0056] In addition, terms such as “below,” “lower side,” “above,” and “upper side” are used to explain the relationship between the structures shown in the drawings. These terms are relative concepts and are explained based on the directions shown in the drawings.

[0057] Terms such as "including" or "having" should be understood as specifying the existence of features, numbers, steps, tasks, constituent elements, accessories or combinations thereof recorded in the specification, and do not preclude the existence or additional possibility of one or more other features or numbers, steps, tasks, constituent elements, accessories or combinations thereof.

[0058] In this specification, "directly configured" may mean that there is no additional layer, film, region, plate, etc. between a layer, film, region, plate, etc. and another part. For example, "directly configured" may mean configuring between two layers or two parts without using an additional part such as an adhesive part.

[0059] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) have the same meanings as those commonly understood by those skilled in the art to which the present invention pertains. Furthermore, terms that are the same as those defined in commonly used dictionaries should be interpreted as having the same meanings as those in the context of the relevant art, and should not be interpreted as having highly idealized or overly formal meanings unless expressly defined herein.

[0060] On the other hand, in this specification, "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 amino group, a silyl group, an oxy group, a thiol 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. Furthermore, each of the substituents exemplified above may be substituted or unsubstituted. For example, a biphenyl group may be interpreted as an aryl group or a phenyl group substituted with a phenyl group.

[0061] In this specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0062] In the present specification, an alkyl group may be a linear or branched group. The number of carbon atoms in the alkyl group is 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, tert-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2-butyldecyl, 2-Hexyldecyl, 2-octyldecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, 2-ethyleicosyl, 2-butyleicosyl, 2-hexyleicosyl, 2-octyleicosyl, n-heneicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl and n-triacontyl etc., but are not limited thereto.

[0063] In this specification, an alkenyl group refers to a hydrocarbon group containing one or more carbon-carbon double bonds within or at the end of an alkyl group having two or more carbon atoms. An alkenyl group may be straight-chain or branched. The number of carbon atoms is not particularly limited, but is preferably 2 to 30, 2 to 20, or 2 to 10. Examples of alkenyl groups include, but are not limited to, vinyl, 1-butenyl, 1-pentenyl, 1,3-butadienyl, styryl, and styrylvinyl.

[0064] In this specification, an alkynyl group refers to a hydrocarbon group containing one or more carbon-carbon triple bonds within or at the end of an alkyl group having two or more carbon atoms. An alkynyl group may be straight-chain or branched. The number of carbon atoms is not particularly limited, but is preferably 2 to 30, 2 to 20, or 2 to 10. Specific examples of alkynyl groups include, but are not limited to, ethynyl and propynyl.

[0065] In this specification, aryl means any functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group may be a monocyclic aryl group or a polycyclic aryl group. The number of ring carbon atoms of the aryl group may be 6 or more and 60 or less, 6 or more and 50 or less, 6 or more and 40 or less, 6 or more and 30 or less, 6 or more and 20 or less, or 6 or more and 15 or less. Examples of aryl groups include phenyl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl, biphenyl, terphenyl, quaterphenyl, quinquephenyl, hexyl, triphenylene, pyrenyl, benzofluoranthenyl, etc., but not limited to these.

[0066] In this specification, the heteroaryl group may contain one or more of B, O, N, P, Si, and S as heteroatoms. When the heteroaryl group contains two or more heteroatoms, the two or more heteroatoms may be the same or different. The heteroaryl group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group. The number of carbon atoms in the ring of the heteroaryl group may be 2 or more and 60 or less, 2 or more and 50 or less, 2 or more and 40 or less, 2 or more and 30 or less, 2 or more and 20 or less, or 2 or more and 10 or less. Examples of heteroaryl groups include, but are not limited to, thienyl, furyl, pyrrolyl, imidazolyl, pyridyl, bipyridyl, pyrimidyl, triazinyl, triazolyl, acridinyl, pyridazinyl, pyrazinyl, quinolyl, quinazolinyl, quinoxalinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolyl, indolyl, carbazolyl, N-arylcarbazolyl, N-heteroarylcarbazolyl, N-alkylcarbazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothienyl, dibenzothienyl, thienothiphenyl, benzofuranyl, phenanthrolinyl, thiazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, phenothiazinyl, dibenzothiazolyl, and dibenzofuranyl.

[0067] In this specification, the aforementioned description of the aryl group applies to an arylene group except that it is a divalent group. The aforementioned description of the heteroarylene group applies to a heteroaryl group except that it is a divalent group.

[0068] In the present specification, the acyl halide may mean a substituent having the following structure S1.

[0069]

[0070] In structure S1, X is a halogen atom.

[0071] In the present specification, the hydroxy group may mean a substituent having a “—OH” structure.

[0072] In the present specification, the thiol group may mean a substituent having a “—SH” structure.

[0073] In this specification, the term "sulfo group" may include an alkylsulfo group and an arylsulfo group. A sulfo group may refer to an alkyl group or an aryl group defined above in which a sulfur atom is bonded. Examples of sulfo groups include, but are not limited to, methylsulfo, ethylsulfo, propylsulfo, pentylsulfo, hexylsulfo, octylsulfo, dodecylsulfo, cyclopentylsulfo, cyclohexylsulfo, phenylsulfo, and naphthylsulfo.

[0074] In this specification, an oxy group may refer to an alkyl group or an aryl group defined above in which an oxygen atom is bonded. Oxy groups may include alkoxy groups and aryloxy groups. Alkoxy groups may be linear, branched, or cyclic. The number of carbon atoms in an alkoxy group is not particularly limited, but may be, for example, 1 to 20 or 1 to 10. Examples of oxy groups include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, octyloxy, nonyloxy, decyloxy, and benzyloxy.

[0075] In this specification, the number of carbon atoms in the amino group is not particularly limited, but can be 1 or more and 30 or less. The amino group can include an alkylamino group and an arylamino group. Examples of the amino group include methylamino group, dimethylamino group, phenylamino group, diphenylamino group, naphthylamino group, 9-methyl-anthrylamino group, triphenylamino group, etc., but are not limited to these.

[0076] In this specification, a dithioacid group may refer to a substituent having an -S2R structure. Here, R may be a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms.

[0077] In this specification, phosphino may include alkylphosphino and arylphosphino. A phosphino may mean an alkyl or aryl group in the above definition combined with a phosphorus atom. Examples of phosphino include methylphosphino, ethylphosphino, propylphosphino, butylphosphino, pentylphosphino, hexylphosphino, octylphosphino, cyclopentylphosphino, cyclohexylphosphino, phenylphosphino, diphenylphosphino, and triphenylphosphino, but are not limited thereto.

[0078] In the present specification, the carboxyl group may mean a substituent represented by the following structure C1.

[0079]

[0080] In this specification, (meth)acrylate may mean acrylate as well as methacrylate.

[0081] On the other hand, in this specification, And "-*" means the location of the connection.

[0082] Hereinafter, a quantum dot composition, a method for preparing the quantum dot composition, and a display device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0083] Figure 1 FIG. 1 is a perspective view showing an embodiment of the electronic device EA. Figure 2 FIG. 1 is an exploded perspective view of an electronic device EA according to an embodiment. Figure 3 is with Figure 1 The II' line corresponds to a cross-sectional view of the display device DD according to an embodiment.

[0084] In one embodiment, the electronic device EA may be a large electronic device such as a television, monitor, or external billboard. Alternatively, the electronic device EA may be a small or medium-sized electronic device such as a personal computer, laptop computer, personal digital assistant, car navigation unit, game console, smartphone, tablet, or camera. Furthermore, these are merely examples; other electronic devices may be employed without departing from the concepts of the present invention. In this embodiment, the electronic device EA is exemplarily shown as a smartphone.

[0085] The electronic device EA may include a display device DD and a housing HAU. The display device DD may display an image IM through a display surface IS, and a user may recognize an image provided through a transmissive area TA corresponding to the front face FS of the electronic device EA. The image IM may include a dynamic image and a static image. Figure 1 , the front surface FS is shown to be parallel to a plane defined by the first direction DR1 and the second direction DR2 crossing the first direction DR1. However, this is exemplary, and in other embodiments, the front surface FS of the electronic device EA may have a curved shape.

[0086] The normal direction of the front surface FS of the electronic device EA, that is, the direction of the display image IM in the thickness direction of the electronic device EA, indicates a third direction DR3. The front (or top) and back (or bottom) of each component can be divided by the third direction DR3. Meanwhile, the directions indicated by the first to third directions DR1, DR2, and DR3 can be transformed into other directions as relative concepts.

[0087] On the other hand, although not shown in the drawings, the electronic device EA may include a foldable display device including a folding area and a non-folding area or a curved display device including at least one curved portion, etc.

[0088] The electronic device EA may include a display device DD and a housing HAU. In the electronic device EA, the front surface FS may correspond to the front surface of the display device DD and the front surface of the window WP. Therefore, the front surface of the electronic device EA, the front surface of the display device DD, and the front surface of the window WP will be referred to using the same reference numeral FS.

[0089] The housing HAU can accommodate the display device DD. The housing HAU can cover the display device DD, exposing the upper surface of the display surface IS of the display device DD. The housing HAU can cover the side and bottom surfaces of the display device DD, exposing the entire upper surface. However, embodiments are not limited thereto, and the housing HAU can cover not only the side and bottom surfaces of the display device DD, but also a portion of the upper surface.

[0090] In an embodiment of the electronic device EA, the window WP may include an optically transparent insulating material. The window WP may include a transmissive area TA and a frame area BZA. The front surface FS of the window WP including the transmissive area TA and the frame area BZA corresponds to the front surface FS of the electronic device EA.

[0091] exist Figure 1 as well as Figure 2 In the embodiment, the transmissive area TA is shown as a quadrangular shape with rounded vertices. However, this is merely an example, and the transmissive area TA may have various shapes and is not limited to any one embodiment.

[0092] The transmissive area TA may be an optically transparent area. The frame area BZA may be a region having a relatively lower light transmittance than the transmissive area TA. The frame area BZA may have a predetermined color. The frame area BZA may be adjacent to the transmissive area TA and surround the transmissive area TA. The frame area BZA may define the shape of the transmissive area TA. However, embodiments are not limited to the illustrations; the frame area BZA may be disposed adjacent to only one side of the transmissive area TA, or a portion may be omitted.

[0093] The display device DD may be disposed below the window WP. In this specification, “below” may mean a direction opposite to a direction in which the display device DD provides an image.

[0094] In one embodiment, the display device DD may be a structure that substantially generates an image IM. The image IM generated in the display device DD is displayed on the display surface IS and is externally visible to a user through the transmissive area TA. The display device DD includes a display area DA and a non-display area NDA. The display area DA may be an area activated by an electrical signal. The non-display area NDA may be an area covered by a bezel area BZA. The non-display area NDA is adjacent to the display area DA. The non-display area NDA may surround the display area DA.

[0095] Reference Figure 3 The display device DD may include a display panel DP and a light control layer PP disposed on the display panel DP. The display panel DP may include a display element layer DP-EL. The display element layer DP-EL includes light emitting elements.

[0096] The light control layer PP may be disposed on the display panel DP to control the reflected light from the display panel DP by the external light. The light control layer PP may include, for example, a polarizing layer or a color filter layer.

[0097] In the display device DD of one embodiment, the display panel DP may be a light-emitting display panel. For example, the display panel DP may be a quantum dot light-emitting display panel including quantum dot light-emitting elements. However, the embodiment is not limited thereto.

[0098] The display panel DP may include a base substrate BS, a circuit layer DP-CL disposed on the base substrate BS, and a display element layer DP-EL disposed on the circuit layer DP-CL.

[0099] The base substrate BS may be a component that provides a base surface for the display element layer DP-EL configuration. The base substrate BS may be a glass substrate, a metal substrate, a plastic substrate, or the like. However, embodiments are not limited thereto, and the base substrate BS may be an inorganic layer, an organic layer, or a composite material layer. The base substrate BS may be a flexible substrate that can be easily bent or folded.

[0100] In one embodiment, the circuit layer DP-CL may be disposed on the base substrate BS and include a plurality of 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 a switching transistor and a driving transistor for driving the light-emitting elements ED of the display element layer DP-EL.

[0101] Figure 4FIG. 1 is an enlarged plan view showing a portion of a display device DD according to an embodiment of the present invention. Figure 5 is a cross-sectional view of a display device DD according to an embodiment of the present invention. Figure 5 Shown with Figure 4 The II-II' line corresponds to the part. Figure 6a as well as Figure 6b FIG. 1 is a diagram schematically showing the structure of a quantum dot complex according to an embodiment of the present invention.

[0102] Reference Figure 4 as well as Figure 5 The display device DD may include a peripheral region NPXA and light-emitting regions PXA-B, PXA-G, and PXA-R. Each of the light-emitting regions PXA-B, PXA-G, and PXA-R may be a region where light generated by the light-emitting element ED-a is emitted. The light-emitting regions PXA-B, PXA-G, and PXA-R may be spaced apart from each other on a plane.

[0103] The light emitting areas PXA-B, PXA-G, and PXA-R can be divided into multiple groups according to the color of the light emitted. Figure 4 as well as Figure 5 In the display device DD of one embodiment shown, three light-emitting regions PXA-B, PXA-G, and PXA-R are exemplarily shown, emitting blue, green, and red light. For example, the display device DD of one embodiment may include a first light-emitting region PXA-B, a second light-emitting region PXA-G, and a third light-emitting region PXA-R, which are separated from each other. In this specification, the first light-emitting region PXA-B may be referred to as a blue light-emitting region, the second light-emitting region PXA-G may be referred to as a green light-emitting region, and the third light-emitting region PXA-R may be referred to as a red light-emitting region.

[0104] exist Figure 4 In the figure, the first to third light-emitting regions PXA-B, PXA-G, and PXA-R are shown as having the same shape in a plane and having different areas in a plane, but the embodiment is not limited thereto. The areas of at least two of the first to third light-emitting regions PXA-B, PXA-G, and PXA-R may be the same. The areas of the first to third light-emitting regions PXA-B, PXA-G, and PXA-R may be set according to the color of the emitted light. It may be that, among the primary colors, the area of ​​the pixel region emitting green light is the largest, and the area of ​​the pixel region emitting blue light is the smallest.

[0105] Each of the light-emitting regions PXA-B, PXA-G, and PXA-R can be a region demarcated by a pixel-defining layer PDL. The peripheral region NPXA can be the region between adjacent light-emitting regions PXA-B, PXA-G, and PXA-R, corresponding to the pixel-defining layer PDL. On the other hand, in this specification, each of the light-emitting regions PXA-B, PXA-G, and PXA-R can correspond to a pixel. The light-emitting element ED-a can be arranged in an opening OH defined by the pixel-defining layer PDL to form a demarcation.

[0106] exist Figure 4 In the figure, each of the first to third light-emitting regions PXA-B, PXA-G, and PXA-R is shown as a rectangular shape in a plane, but the present invention is not limited thereto. Each of the first to third light-emitting regions PXA-B, PXA-G, and PXA-R may have a polygonal shape such as a rhombus or pentagon in a plane. In addition, each of the first to third light-emitting regions PXA-B, PXA-G, and PXA-R may have a rectangular shape with rounded corners.

[0107] exist Figure 4 In the figure, the second light-emitting region PXA-G is arranged in the first row, and the first light-emitting region PXA-B and the third light-emitting region PXA-R are arranged in the second row. However, this is merely an example, and the arrangement of the first to third light-emitting regions PXA-B, PXA-G, and PXA-R can be modified in various ways. For example, the first to third light-emitting regions PXA-B, PXA-G, and PXA-R can be arranged in the same row.

[0108] Any one of the first to third light-emitting regions PXA-B, PXA-G, and PXA-R may emit a first color light, another may emit a second color light different from the first color light, and the remaining one may emit a third color light different from the first and second color lights. In this embodiment, the first light-emitting region PXA-B provides the first light corresponding to a portion of the source light. For example, the third light-emitting region PXA-R may emit red light, the second light-emitting region PXA-G may emit green light, and the first light-emitting region PXA-B may emit blue light.

[0109] The display area DA may define a well bank area BWA. The well bank area BWA may be formed to prevent defects due to mis-landing during the printing process of the plurality of light control parts CCP-B, CCP-G, and CCP-R included in the light conversion layer CCL described later. The well bank area BWA may be an area where a portion of the barrier portion BK is removed. Figure 4 2 shows that two bank well areas BWA are formed adjacent to the second light emitting region PXA-G, but the embodiment is not limited thereto, and the shape and arrangement of the bank well areas BWA may be variously modified.

[0110] Reference Figure 5 In one embodiment, a display device DD may include a display panel DP and a light control layer PP disposed on the display panel DP. The light control layer PP may include a light conversion layer CCL disposed on the display panel DP. Furthermore, the light control layer PP may further include a color filter layer CFL. The color filter layer CFL may be disposed between the base layer BL and the light conversion layer CCL.

[0111] The display panel DP may be a light-emitting display panel, for example, an organic electroluminescence (OLED) display panel or a quantum dot (QD) luminescent display panel.

[0112] The display panel DP may include a base substrate BS, a circuit layer DP-CL provided on the base substrate BS, and a display element layer DP-EL.

[0113] The display element layer DP-EL may include a light-emitting element ED-a as a display element. The light-emitting element ED-a may generate the aforementioned source light and may include a light-emitting layer configured to entirely overlap with the first light-emitting region PXA-B, the second light-emitting region PXA-G, and the third light-emitting region PXA-R. The light-emitting element ED-a may overlap with at least each of the first light-emitting region PXA-B, the second light-emitting region PXA-G, and the third light-emitting region PXA-R.

[0114] The display element layer DP-EL includes a pixel definition layer PDL. The pixel definition layer PDL may be an organic layer or an inorganic layer. The light-emitting element ED-a may be at least partially disposed within an opening OH defined in the pixel definition layer PDL.

[0115] The pixel defining film PDL can be formed of a polymer resin. For example, the pixel defining film PDL can be formed by including a polyacrylate resin or a polyimide resin. In addition, the pixel defining film PDL can be formed by including an inorganic substance in addition to the polymer resin. On the other hand, the pixel defining film PDL can be formed by including a light absorbing substance, or by including a black pigment or a black dye. The pixel defining film PDL formed by including a black pigment or a black dye can realize a black pixel defining film. When the pixel defining film PDL is formed, carbon black or the like can be used as the black pigment or the black dye, but the embodiment is not limited thereto.

[0116] In addition, the pixel definition layer PDL may be formed of an inorganic material. For example, the pixel definition layer PDL may include silicon nitride (SiN x ), silicon oxide (SiO x), silicon oxynitride (SiO x N y ) etc. 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 divided from the peripheral region NPXA by the pixel defining film PDL.

[0117] The display element layer DP-EL may include a light-emitting element ED-a. The light-emitting element ED-a includes a first electrode EL1 and a second electrode EL2 facing each other, and a plurality of layers OL disposed between the first electrode EL1 and the second electrode EL2. The plurality of layers OL may include a hole transport region, a light-emitting layer, and an electron transport region. An encapsulation layer TFE may be disposed on the light-emitting element ED-a.

[0118] In the light-emitting element ED-a included in the display panel DP of one embodiment, the light-emitting layer may include a host as an organic electroluminescent material and a dopant, or may include quantum dots according to one embodiment described above. In the display panel DP of one embodiment, the light-emitting element ED-a may emit blue light.

[0119] The hole transport region and the electron transport region in the light emitting element ED-a included in the display panel DP of one embodiment may be applicable to the Figure 9b The contents of the hole transport region and the electron transport region described later are the same.

[0120] The encapsulation layer TFE may cover the light-emitting element ED-a. The encapsulation layer TFE may be a single layer or a stack of multiple layers. The encapsulation layer TFE may be a thin film encapsulation layer. The encapsulation layer TFE protects the light-emitting element ED-a. The encapsulation layer TFE may cover the light-emitting element ED-a disposed in the opening OH and fill the opening OH.

[0121] A light control layer PP may be disposed on the encapsulation layer TFE. The light control layer PP may include a light conversion layer CCL, a color filter layer CFL, and a base layer BL.

[0122] The light conversion layer CCL may include a plurality of barrier portions BK spaced apart from each other and light control portions CCP-B, CCP-G, and CCP-R disposed between the barrier portions BK. The barrier portion BK may be formed by including a polymer resin and a hydrophobic additive. The barrier portion BK may be formed by including a light absorbing substance, or may be formed by including a pigment or a dye. For example, the barrier portion BK may be formed by including a black pigment or a black dye, thereby realizing a black barrier portion. When forming the black barrier portion, carbon black or the like may be used as the black pigment or the black dye, but the embodiment is not limited thereto.

[0123] It can be that multiple light control parts CCP-B, CCP-G, and CCP-R are arranged in the opening part OH defined by the barrier part BK, and at least a part of the multiple light control parts CCP-B, CCP-G, and CCP-R can change the optical properties of the source light.

[0124] The light conversion layer CCL may include a first light control unit CCP-B that transmits first light, serving as source light, a second light control unit CCP-G that includes a first quantum dot complex QD-C2a that converts the first light into second light, and a third light control unit CCP-R that includes a second quantum dot complex QD-C3a that converts the first light into third light. The second light may be light in a longer wavelength region than the first light, and the third light may be light in a longer wavelength region than both the first and second light. For example, the first light may be blue light, the second light may be green light, and the third light may be red light.

[0125] The first light-control part CCP-B of the light conversion layer CCL may not include a quantum dot complex. However, embodiments are not limited thereto, and the first light-control part CCP-B of the light conversion layer CCL may also include a quantum dot complex. The quantum dot complex included in the first light-control part CCP-B may emit blue light as the first color light.

[0126] At least one of the quantum dot complexes QD-C2a and QD-C3a included in the light control units CCP-G and CCP-R may be a quantum dot complex according to one embodiment, described later. In one embodiment, the first quantum dot complex QD-C2a may be a quantum dot complex according to one embodiment, described later. However, the present invention is not limited thereto, and each of the first and second quantum dot complexes QD-C2a and QD-C3a may be a quantum dot complex according to one embodiment, described later.

[0127] In one embodiment, the first and second quantum dot complexes QD-C2a and QD-C3a included in the second and third light-control units CCP-G and CCP-R may include quantum dots having different core materials. Alternatively, the quantum dots included in the first and second quantum dot complexes QD-C2a and QD-C3a may include the same core material.

[0128] In one embodiment, the first and second quantum dot complexes QD-C2a and QD-C3a may include quantum dots having different diameters. For example, the first quantum dot complex QD-C2a of the second light control unit CCP-G, which emits light in a relatively short wavelength region, may include quantum dots having a relatively smaller average diameter than the second quantum dot complex QD-C3a of the third light control unit CCP-R, which emits light in a relatively long wavelength region.

[0129] On the other hand, the average diameter in this specification corresponds to a value obtained by arithmetic averaging the diameters of a plurality of quantum dot particles. On the other hand, the diameter of a quantum dot particle may be an average value of the width of the quantum dot particle in a cross section.

[0130] The relationship between the average diameters of the first and second quantum dot complexes QD-C2a and QD-C3a is not limited to the above-mentioned limitations. Specifically, the quantum dots contained in the first and second quantum dot complexes QD-C2a and QD-C3a contained in the light control units CCP-G and CCP-R may have different sizes. Alternatively, the average diameters of the quantum dots in the first and second quantum dot complexes QD-C2a and QD-C3a may be similar, while the remaining diameters may be different.

[0131] A plurality of light control parts CCP-B, CCP-G, and CCP-R may respectively include a matrix resin for dispersing the quantum dot complexes QD-C2a and QD-C3a. The matrix resin is a medium for dispersing the quantum dot complexes QD-C2a and QD-C3a, and may be composed of various resin compositions that can generally be referred to as adhesives. For example, the matrix resin may include acrylic resin, methacrylic resin, urethane resin, fluororesin, epoxy resin, vinyl resin, polyester resin, polyamide resin, polyimide resin, cellulose resin, polyparaxylene resin, silicone resin or a combination thereof. The matrix resin may be a transparent resin. On the other hand, in this specification, the "a" type resin means a functional group containing "a".

[0132] The light conversion layer CCL may further include a filling layer CPL. The filling layer CPL may be disposed under the light control parts CCP-B, CCP-G, CCP-R and the barrier part BK. The filling layer CPL may be disposed between the encapsulation layer TFE and the light control parts CCP-B, CCP-G, CCP-R. The filling layer CPL may serve to prevent the penetration of moisture and / or oxygen (hereinafter referred to as "moisture / oxygen"). The filling layer CPL may be disposed on the light control parts CCP-B, CCP-G, CCP-R to block the light control parts CCP-B, CCP-G, CCP-R from being exposed to moisture / oxygen. The filling layer CPL may include at least one inorganic layer.

[0133] exist Figure 5 In the illustrated embodiment, the light control layer PP may include a color filter layer CFL. That is, the display device DD in the embodiment may further include a color filter layer CFL disposed on the light emitting element ED-a of the display panel DP.

[0134] In the display device DD of an embodiment, the light control layer PP may include a base layer BL and a color filter layer CFL.

[0135] The base layer BL may be a component that provides a base surface for the color filter layer CFL and other configurations. The base layer BL may be a glass substrate, a metal substrate, a plastic substrate, etc. However, the embodiment is not limited thereto, and the base layer BL may be an inorganic layer, an organic layer, or a composite material layer.

[0136] The color filter layer CFL may include a light shielding portion BM and a color filter portion CF. The color filter portion CF may include a plurality of filters CF-B, CF-G, and CF-R. Specifically, the color filter layer CFL may include a first filter CF-B that transmits a first light, a second filter CF-G that transmits a second light, and a third filter CF-R that transmits a third light. 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.

[0137] Each of the optical filters CF-B, CF-G, and CF-R may include a polymer photosensitive resin and a pigment or dye. For example, the first optical filter CF-B may include a blue pigment or dye, the second optical filter CF-G may include a green pigment or dye, and the third optical filter CF-R may include a red pigment or dye.

[0138] On the other hand, the embodiment is not limited thereto, and the first optical filter CF-B may not contain a pigment or dye. The first optical filter CF-B may contain a polymer photosensitive resin and not contain a pigment or dye. The first optical filter CF-B may be transparent. The first optical filter CF-B may be formed of a transparent photosensitive resin.

[0139] The light-shielding portion BM may be a black matrix. The light-shielding portion BM may be formed of an organic or inorganic light-shielding material including a black pigment or a black dye. The light-shielding portion BM can prevent light leakage and define the boundaries between adjacent filters CF-B, CF-G, and CF-R.

[0140] The color filter layer CFL may also include a buffer layer BFL. For example, the buffer layer BFL may be a protective layer that protects the color filters CF-B, CF-G, and CF-R. The buffer layer BFL may be an inorganic layer containing at least one of silicon nitride, silicon oxide, and silicon oxynitride. The buffer layer BFL may be composed of a single layer or multiple layers.

[0141] exist Figure 5In the illustrated embodiment, the first filter CF-B of the color filter layer CFL overlaps with the second filter CF-G and the third filter CF-R, but embodiments are not limited thereto. For example, the first to third filters CF-B, CF-G, and CF-R may be separated by a light shielding portion BM and may not overlap with each other. Alternatively, in one embodiment, each of the first to third filters CF-B, CF-G, and CF-R may be arranged to correspond to each of the blue light-emitting region PXA-B, the green light-emitting region PXA-G, and the red light-emitting region PXA-R.

[0142] and Figure 5 Unlike the examples shown in FIG. 1 , the display device DD of one embodiment may include a polarizing layer (not shown) as the light control layer PP instead of the color filter layer CFL. The polarizing layer (not shown) may block external light provided from the outside to the display panel DP. The polarizing layer (not shown) may block a portion of the external light.

[0143] In addition, the polarizing layer (not shown) can reduce the reflected light generated by the external light from the display panel DP. For example, the polarizing layer (not shown) can have the function of blocking the reflected light when the light provided from the outside of the display device DD is incident on the display panel DP and then emitted again. The polarizing layer (not shown) may be a circular polarizer with a reflection prevention function or the polarizing layer (not shown) may include a linear polarizer and a λ / 4 phase retarder. On the other hand, the polarizing layer (not shown) may be configured on the base layer BL and exposed, or the polarizing layer (not shown) may be configured below the base layer BL.

[0144] Figure 6a FIG. 1 is a diagram schematically showing the structure of a quantum dot complex according to an embodiment of the present invention.

[0145] Reference Figure 6a According to one embodiment, a quantum dot complex QD-C may include a scatterer SP and a plurality of quantum dots QD1 and QD2, and may include a structure in which the scatterer SP and the plurality of quantum dots QD1 and QD2 are connected via ligands S-LD, LD1, and LD2. In one embodiment, the quantum dot complex QD-C may include a structure in which the scatterer SP and the plurality of quantum dots QD1 and QD2 are connected by surface modification with ligands S-LD, LD1, and LD2, and may include a structure in which the scatterer SP and the plurality of quantum dots QD1 and QD2 are connected by chemical bonding with the ligands S-LD bound to the scatterer SP and the ligands LD1 and LD2 bound to the surfaces of the plurality of quantum dots QD1 and QD2.

[0146] More specifically, the quantum dot complex QD-C may include a scatterer SP, first and second quantum dots QD1, QD2, first and second ligands LD1, LD2 bound to the surface of each of the first and second quantum dots QD1, QD2, and a scatterer ligand S-LD bound to the surface of the scatterer SP. In the quantum dot complex QD-C of one embodiment, each of the first and second ligands LD1, LD2 may be chemically bonded to the scatterer ligand S-LD. Through chemical bonding of each of the first and second ligands LD1, LD2 to the scatterer ligand S-LD, each of the first and second quantum dots QD1, QD2 may be connected to the scatterer SP. On the other hand, in this specification, "chemical bonding" may mean ionic bonding or covalent bonding. For example, "chemical bonding" may mean covalent bonding.

[0147] The scatterer SP may refer to organic or inorganic particles that can scatter, refract, or diffuse light emitted from the quantum dots QD1 and QD2. The scatterer may include at least one of TiO2, ZnO, Al2O3, SiO2, and hollow silica. The scatterer may include any one of TiO2, ZnO, Al2O3, SiO2, and hollow silica, or a mixture of two or more selected from TiO2, ZnO, Al2O3, SiO2, and hollow silica. In one embodiment, the scatterer SP may be an inorganic particle. For example, the scatterer SP may be TiO2.

[0148] The quantum dot complex QD-C may include a plurality of quantum dots QD1 and QD2. The plurality of quantum dots QD1 and QD2 may include different core materials. Figure 6a The quantum dot complex QD-C may include a first quantum dot QD1 and a second quantum dot QD2, and the first core CR1 included in the first quantum dot QD1 and the second core CR2 included in the second quantum dot QD2 may include different substances. For example, the first core CR1 may include a first semiconductor nanocrystal, and the second core CR2 may include a second semiconductor nanocrystal different from the first semiconductor nanocrystal.

[0149] The absorption wavelength of the cores contained in the first and second quantum dots QD1 and QD2 can be greater than or equal to 350 nm and less than or equal to 530 nm. The absorption wavelength of the first core CR1 contained in the first quantum dot QD1 can be greater than or equal to 350 nm and less than or equal to 530 nm. The absorption wavelength of the second core CR2 contained in the second quantum dot QD2 can be greater than or equal to 350 nm and less than or equal to 530 nm. As a result, each of the first and second cores CR1 and CR2 can absorb blue light in the aforementioned wavelength range and emit green or red light.

[0150] In one embodiment, each of the first and second quantum dots QD1 and QD2 can absorb the first light and emit a second light or a third light having a longer wavelength than the first light. Each of the first and second quantum dots QD1 and QD2 can absorb the first light and emit a second light having a longer wavelength than the first light. Furthermore, each of the first and second quantum dots QD1 and QD2 can absorb the first light and emit a third light having a longer wavelength than the first light. In one embodiment, the first light can be blue light. That is, the first light can be blue light having a maximum emission wavelength range of 430 nm to 490 nm.

[0151] The maximum emission wavelength range of each of the first and second quantum dots QD1 and QD2 can be greater than or equal to 510 nm and less than or equal to 550 nm. In one embodiment, each of the first and second quantum dots QD1 and QD2 can emit light with a wavelength of greater than or equal to 510 nm and less than or equal to 550 nm. That is, each of the first and second quantum dots QD1 and QD2 can emit green light with a wavelength of greater than or equal to 510 nm and less than or equal to 550 nm. However, the present invention is not limited thereto, and the maximum emission wavelength range of each of the first and second quantum dots QD1 and QD2 can emit light with a wavelength of greater than or equal to 630 nm and less than or equal to 680 nm. That is, each of the first and second quantum dots QD1 and QD2 can emit red light with a wavelength of greater than or equal to 630 nm and less than or equal to 680 nm.

[0152] The quantum dot complex QD-C can increase the external quantum efficiency (EQE) compared to a quantum dot complex containing a single quantum dot by including two quantum dots QD1 and QD2 that emit light of the same color and contain different core materials. The quantum dot complex QD-C can reduce the overlap of the maximum absorption wavelength spectrum and the maximum emission wavelength spectrum by including two quantum dots QD1 and QD2 that emit light of the same color and contain different core materials, thereby preventing the reduction in efficiency due to re-excitation and reabsorption by quantum dots QD1 and QD2.

[0153] Figure 7 Graphs showing the absorption and emission spectra of a light conversion pattern containing a single quantum dot and a light conversion pattern containing two quantum dots. Figure 7In the figure, "A1" corresponds to the absorption spectrum of light conversion pattern 1 containing InP / ZnSeS quantum dots, "A2" corresponds to the emission spectrum of light conversion pattern 1 containing InP / ZnSeS quantum dots, "B1" corresponds to the absorption spectrum of light conversion pattern 2 containing AgInGaS / GaS quantum dots, "B2" corresponds to the emission spectrum of light conversion pattern 2 containing AgInGaS / GaS quantum dots, "C1" corresponds to the absorption spectrum of light conversion pattern 3 containing InP / ZnSeS quantum dots and AgInGaS / GaS quantum dots, and "C2" corresponds to the emission spectrum of light conversion pattern 3 containing InP / ZnSeS quantum dots and AgInGaS / GaS quantum dots. Meanwhile, InP / ZnSeS quantum dots refer to quantum dots having a core containing InP and a shell containing ZnSeS, and AgInGaS / GaS quantum dots refer to quantum dots having a core containing AgInGaS and a shell containing GaS.

[0154] Reference Figure 7 It was confirmed that light conversion pattern 3, which includes two different quantum dots, InP / ZnSeS and AgInGaS / GaS, exhibited less overlap between the absorption and emission wavelength spectra than light conversion patterns 1 and 2, each consisting of a single quantum dot of each of InP / ZnSeS and AgInGaS / GaS. Increased overlap between the absorption and emission wavelength spectra can increase reexcitation and reabsorption of the quantum dots, leading to a decrease in the quantum dot luminescence efficiency. However, when using two different quantum dots to form a light conversion pattern, the overlap between the absorption and emission wavelength spectra can be minimized, thereby preventing a decrease in the efficiency of reexcitation and reabsorption by the quantum dots.

[0155] Refer again Figure 6a In one embodiment, the first and second quantum dots QD1 and QD2 may have a core-shell structure including cores CR1 and CR2 and shells SL1 and SL2 surrounding the cores CR1 and CR2. The first quantum dot QD1 may include a first core CR1 and a first shell SL1 surrounding the first core CR1. The first shell SL1 may fully cover the first core CR1. The second quantum dot QD2 may include a second core CR2 and a second shell SL2 surrounding the second core CR2. The second shell SL2 may fully cover the second core CR2. The shells SL1 and SL2 may perform the role of a protective layer for preventing the chemical denaturation of the cores CR1 and CR2 and maintaining the semiconductor properties and / or the role of a charging layer for imparting electrophoretic properties to the quantum dots. The shells SL1 and SL2 may be single-layer or multi-layer. However, the embodiment is not limited thereto, and Figure 6a Unlike shown, the shells SL1 , SL2 can be omitted in the quantum dots QD1 , QD2 .

[0156] In the case where the quantum dots QD1 and QD2 include shells SL1 and SL2, the shells SL1 and SL2 may contain substances different from the cores CR1 and CR2. It may be that in the first quantum dot QD1, the first core CR1 and the first shell SL1 contain substances different from each other, and in the second quantum dot QD2, the second core CR2 and the second shell SL2 contain substances different from each other. For example, in the first quantum dot QD1, the first core CR1 may contain a first semiconductor nanocrystal, and the first shell SL1 may contain a third semiconductor nanocrystal. In addition, it may be that the second core CR2 contains a second semiconductor nanocrystal, and the second shell SL2 contains a fourth semiconductor nanocrystal. In addition, the first and second shells SL1 and SL2 may each independently contain a metal or non-metal oxide. The first and second shells SL1 and SL2 may each independently contain a metal or non-metal oxide, a semiconductor nanocrystal, or a combination thereof. In one embodiment, the third and fourth semiconductor nanocrystals may be the same as or different from each other.

[0157] Shells SL1 and SL2 may be composed of a single substance, but may also be formed to have a concentration gradient. For example, the concentration of semiconductor nanocrystals within shells SL1 and SL2 decreases as they become closer to cores CR1 and CR2, while the concentration of semiconductor nanocrystals within cores CR1 and CR2 increases.

[0158] In one embodiment, the shells SL1 and SL2 may have a multilayer structure. For example, each of the first and second shells SL1 and SL2 may include a first subshell adjacent to the core CR1 and CR2 and a second subshell separated from the core CR1 and CR2. The second subshell may be separated from the core CR1 and CR2 via the first subshell. Alternatively, the first subshell may cover the core CR1 and CR2, and the second subshell may cover the first subshell. The second subshell may fully cover the first subshell. In the case where the shells SL1 and SL2 included in the quantum dots QD1 and QD2 include the first subshell and the second subshell, the surface of the quantum dots QD1 and QD2 may be defined by the outside of the second subshell. That is, it may be covered by the second subshell so that the first subshell is not exposed from the quantum dots QD1 and QD2.

[0159] In one embodiment, the cores CR1, CR2 and the shells SL1, SL2 may each independently comprise semiconductor nanocrystals selected from Group II-VI compounds, Group III-VI compounds, Group I-III-VI compounds, Group III-V compounds, Group III-II-V compounds, Group IV-VI compounds, Group IV elements, Group IV compounds, and combinations thereof.

[0160] The II-VI compound can be selected from the group consisting of binary compounds selected from the group consisting of CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS and mixtures thereof, binary compounds selected from the group consisting of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdH The present invention can be selected from the group consisting of a ternary compound selected from the group consisting of CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS and a mixture thereof, and a quaternary compound selected from the group consisting of HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and a mixture thereof.

[0161] The III-VI compounds may include binary compounds such as In2S3, In2Se3, ternary compounds such as InGaS3, InGaSe3, or any combination thereof.

[0162] The Group I-III-VI compound can be selected from a ternary compound selected from the group consisting of AgInS, AgInS2, CuInS, CuInS2, AgGaS2, CuGaS2, CuGaO2, AgGaO2, AgAlO2 and mixtures thereof, or a quaternary compound such as AgInGaS2, CuInGaS2, etc.

[0163] The III-V compound can be selected from the group consisting of a binary compound selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; a ternary compound selected from the group consisting of GaNPs, GaNAs, GaNSb, GaPAs, GaPSb, AlNPs, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InAlP, InNP, InNAs, InNSb, InPAs, InPSb, and mixtures thereof; and a quaternary compound selected from the group consisting of GaAlNPs, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNPs, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNPs, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof. Alternatively, the III-V compound may further contain a Group II metal. For example, InZnP or the like can be selected as the III-II-V group compound.

[0164] The IV-VI compound can be selected from the group consisting of binary compounds selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; ternary compounds selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; and quaternary compounds selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof. The Group IV element can be selected from the group consisting of Si, Ge, and mixtures thereof. The Group IV compound can be a binary compound selected from the group consisting of SiC, SiGe, and mixtures thereof. In this case, the binary, ternary, or quaternary compound can be present in a uniform concentration within the particle, or can be present separately within the same particle with locally different concentration distributions.

[0165] Examples of metal or non-metal oxides include binary compounds such as SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4, NiO, or ternary compounds such as MgAl2O4, CoFe2O4, NiFe2O4, CoMn2O4, but the present invention is not limited thereto.

[0166] Quantum dots can have a full width at half maximum (FWHM) of their emission wavelength spectrum of approximately 45 nm or less, preferably approximately 40 nm or less, and more preferably approximately 30 nm or less. Within this range, they can improve color purity or color reproducibility. Furthermore, light emitted by these quantum dots is omnidirectional, which can improve the viewing angle of the light.

[0167] In addition, the form of quantum dots is not particularly limited to the common form in this field, but more specifically, spherical, pyramidal, multi-arm or cubic nanoparticles, nanotubes, nanowires, nanofibers, nanoplate particles and the like can be used.

[0168] Quantum dots can adjust the color of the light they emit based on their particle size, allowing them to emit a variety of luminescent colors, such as blue, red, and green. The smaller the particle size of the quantum dots, the shorter the wavelength of light they can emit. For example, among quantum dots with the same core, the particle size of quantum dots that emit green light can be smaller than that of quantum dots that emit red light. Furthermore, among quantum dots with the same core, the particle size of quantum dots that emit blue light can be smaller than that of quantum dots that emit green light. However, embodiments are not limited thereto, and even among quantum dots with the same core, the particle size can be adjusted based on, for example, the shell material and shell thickness.

[0169] On the other hand, in the case where quantum dots have various luminescent colors such as blue, red, and green, the quantum dots having different luminescent colors may have core materials different from each other.

[0170] Refer again Figure 6a In a quantum dot complex QD-C of one embodiment, the first core CR1 may include a Group III-V compound, and the second core CR2 may include a Group I-III-VI compound. For example, the first core CR1 may include InP, and the second core CR2 may include AgInGaS. The quantum dot complex QD-C of one embodiment includes a first quantum dot QD1 including a first core CR1 including a Group III-V compound and a second quantum dot QD2 including a second core CR2 including a Group I-III-VI compound, thereby achieving high blue light absorption.

[0171] In one embodiment, the first and second quantum dots QD1 and QD2 may be non-Cd quantum dots, that is, the first and second quantum dots QD1 and QD2 may not contain cadmium (Cd).

[0172] In one embodiment, the diameters of the first and second quantum dots QD1 and QD2 can be 1 nm or greater and 10 nm or less, respectively. When the first and second quantum dots QD1 and QD2 fall within the aforementioned average particle size ranges, they can exhibit characteristic quantum dot behavior and possess excellent dispersibility. Furthermore, by varying the average particle size of the quantum dots within the aforementioned ranges, the emission wavelength of the quantum dots and / or their semiconductor properties can be varied.

[0173] The quantum dot complex QD-C includes first and second ligands LD1 and LD2 that are bound to the surface of each of the first and second quantum dots QD1 and QD2. The first ligand LD1 may be bound to the surface of the first quantum dot QD1, and the second ligand LD2 may be bound to the surface of the second quantum dot QD2. In the case where the first quantum dot QD1 includes a first shell SL1 that encapsulates the first core CR1, the first ligand LD1 may be bound to the surface of the first shell SL1 of the first quantum dot QD1 and exposed to the outside of the first shell SL1. In addition, in the case where the second quantum dot QD2 includes a second shell SL2 that encapsulates the second core CR2, the second ligand LD2 may be bound to the surface of the second shell SL2 of the second quantum dot QD2 and exposed to the outside of the second shell SL2.

[0174] The ligands LD1 and LD2 may respectively include heads HD1 and HD2 bound to the surfaces of the quantum dots QD1 and QD2 and tails TL1 and TL2 separated from the surfaces of the quantum dots QD1 and QD2 and bound to the scatterer ligand S-LD. Figure 6a As shown, when quantum dots QD1 and QD2 include shells SL1 and SL2 that encapsulate cores CR1 and CR2, ligands LD1 and LD2 can bind to the surfaces of shells SL1 and SL2. For example, the first quantum dot QD1 may include a first core CR1 and a first shell SL1 that encapsulates the first core CR1, and the first ligand LD1 may bind to the surface of the first shell SL1. Alternatively, the second quantum dot QD2 may include a second core CR2 and a second shell SL2 that encapsulates the second core CR2, and the second ligand LD2 may bind to the surface of the second shell SL2.

[0175] The heads HD1 and HD2 can be located at one end of the ligands LD1 and LD2 to connect the quantum dots QD1 and QD2 to the ligands LD1 and LD2. The tails TL1 and TL2 can be located at the other end of the ligands LD1 and LD2 to connect the ligands LD1 and LD2 to the scatterer ligand S-LD. In addition, the ligands LD1 and LD2 can also include connecting portions CN1 and CN2 disposed between the heads HD1 and HD2 and the tails TL1 and TL2. That is, the ligands LD1 and LD2 can include heads HD1 and HD2, connecting portions CN1 and CN2 connected to the heads HD1 and HD2, and tails TL1 and TL2 connected to the connecting portions CN1 and CN2. The connecting portions CN1 and CN2 can be portions used to increase the dispersibility of the quantum dots QD1 and QD2.

[0176] like Figure 6a As shown, the first ligand LD1 may include a first head HD1 bound to the surface of the first quantum dot QD1 and a first tail TL1 separated from the surface of the first quantum dot QD1 and bound to the scatterer ligand S-LD. In addition, the first ligand LD1 may also include a first connecting portion CN1 configured between the first head HD1 and the first tail TL1 to connect the first head HD1 and the first tail TL1. The second ligand LD2 may include a second head HD2 bound to the surface of the second quantum dot QD2 and a second tail TL2 separated from the surface of the second quantum dot QD2 and bound to the scatterer ligand S-LD. In addition, the second ligand LD2 may also include a second connecting portion CN2 configured between the second head HD2 and the second tail TL2 to connect the second head HD2 and the second tail TL2.

[0177] The scatterer SP can be connected to the first and second quantum dots QD1 and QD2, respectively. The scatterer ligand S-LD bound to the surface of the scatterer SP can be connected to the first ligand LD1 bound to the surface of the first quantum dot QD1 and the second ligand LD2 bound to the surface of the second quantum dot QD2.

[0178] The scatterer SP and the first and second quantum dots QD1 and QD2 can be connected to each other through ligands. More specifically, the scatterer ligand S-LD bound to the surface of the scatterer SP and the first ligand LD1 bound to the surface of the first quantum dot QD1 can chemically bond to connect the scatterer SP and the first quantum dot QD1. In addition, the scatterer ligand S-LD bound to the surface of the scatterer SP and the second ligand LD2 bound to the surface of the second quantum dot QD2 can chemically bond to connect the scatterer SP and the second quantum dot QD2.

[0179] In one embodiment, the scatterer ligand S-LD may include one end that is bound to the scatterer SP and the other end that is separated from the scatterer SP and includes a first functional group that can form a chemical bond with the first and second ligands LD1 and LD2. For example, the scatterer ligand S-LD may include a scatterer head S-HD that is bound to the surface of the scatterer SP and a scatterer tail S-TL that is separated from the surface of the scatterer SP. The scatterer tail S-TL may include a first functional group that can form a chemical bond with the first and second ligands LD1 and LD2. In addition, the scatterer ligand S-LD may also include a scatterer connecting portion S-CN that connects the scatterer head S-HD and the scatterer tail S-TL.

[0180] In the quantum dot complex QD-C of one embodiment, the scatterer head S-HD included in the scatterer ligand S-LD can be bound to a cation or anion provided on the surface of the scatterer SP. In the case where the scatterer head S-HD includes one functional group for binding to the surface of the scatterer SP, the scatterer ligand S-LD can be a monodentate ligand. In the case where the scatterer head S-HD includes two functional groups for binding to the surface of the scatterer SP, the scatterer ligand S-LD can be a bidentate ligand. The scatterer head S-HD includes a functional group for binding to the surface of the scatterer SP, and the scatterer ligand S-LD can be effectively bound to the scatterer SP. In one embodiment, the scatterer head S-HD can be an amine group, a thiol group, a hydroxyl group, a dithioacid group, a phosphine group, a phosphine oxide group, a catechol group or a carboxyl group, but is not limited thereto.

[0181] In the quantum dot complex QD-C of one embodiment, the scatterer tail S-TL included in the scatterer ligand S-LD can form a chemical bond with the first and second ligands LD1 and LD2. The scatterer tail S-TL can include a first functional group that forms a chemical bond with the first and second ligands LD1 and LD2. In one embodiment, the first functional group can include a reactive functional group that can chemically bond with the first and second ligands LD1 and LD2. The first functional group can include a nucleophilic functional group or an electrophilic functional group. For example, the first functional group can be a nucleophilic functional group including at least one of a thiol group, an amine group, a hydroxyl group, an azide group, and an oxetane group, or an electrophilic functional group including at least one of an alkenyl group, an alkynyl group, a carboxyl group, an acyl halide group, and a (meth)acrylate group. In one embodiment, the first functional group can include at least one of a thiol group, an amine group, a hydroxyl group, an azide group, and an oxetane group. For example, the first functional group may be one selected from the group consisting of a thiol group, an amine group, a hydroxyl group, an azide group, and an oxetane group.

[0182] In the quantum dot complex QD-C of one embodiment, when the scatterer ligand S-LD further includes a scatterer connector S-CN connecting the scatterer head S-HD and the scatterer tail S-TL, the scatterer connector S-CN may be an ethylene glycol group, a substituted or unsubstituted divalent alkyl group having 1 or more and 30 or less carbon atoms, a substituted or unsubstituted divalent alkenyl group having 2 or more and 30 or less carbon atoms, a substituted or unsubstituted divalent sulfide group, a substituted or unsubstituted divalent oxy group, a substituted or unsubstituted divalent aromatic group having 6 or more and 60 or less ring carbon atoms, or a substituted or unsubstituted divalent heteroaromatic group having 2 or more and 60 or less ring carbon atoms. However, the embodiment is not limited thereto, and the scatterer connector S-CN may also be omitted in the scatterer ligand S-LD. On the other hand, an "ethylene glycol group" may refer to a group having -O(C2H4) m Here, m is an integer of 1 to 30.

[0183] In the quantum dot complex QD-C of one embodiment, the first and second heads HD1 and HD2 included in the first and second ligands LD1 and LD2 can respectively bind to cations provided on the surfaces of the quantum dots QD1 and QD2. When the first and second heads HD1 and HD2 contain one functional group for binding to the surfaces of the quantum dots QD1 and QD2, the first and second ligands LD1 and LD2 can be monodentate ligands. When the first and second heads HD1 and HD2 contain two functional groups for binding to the surfaces of the quantum dots QD1 and QD2, the first and second ligands LD1 and LD2 can be bidentate ligands. The first and second heads HD1 and HD2 contain functional groups for binding to the surfaces of the quantum dots QD1 and QD2, and the ligands LD1 and LD2 can effectively bind to the quantum dots QD1 and QD2. In one embodiment, the first and second heads HD1 and HD2 may be independently an amino group, a thiol group, a hydroxyl group, a dithioate group, a phosphine group, a phosphine oxide group, a catechol group, or a carboxyl group.

[0184] In the quantum dot complex QD-C of one embodiment, each of the first and second tails TL1 and TL2 included in the first and second ligands LD1 and LD2 can form a bond with the scatterer ligand S-LD. Each of the first and second tails TL1 and TL2 can include a functional group that forms a bond with the scatterer ligand S-LD. Alternatively, the first tail TL1 included in the first ligand LD1 may include a second functional group that forms a chemical bond with the first functional group included in the scatterer ligand S-LD, and the second tail TL2 included in the second ligand LD2 may include a third functional group that forms a chemical bond with the first functional group included in the scatterer ligand S-LD.

[0185] The second and third functional groups may each independently comprise a nucleophilic functional group or an electrophilic functional group. For example, the second and third functional groups may each independently comprise a nucleophilic functional group comprising at least one of a thiol group, an amine group, a hydroxyl group, an azide group, and an oxetane group, or an electrophilic functional group comprising at least one of an alkenyl group, an alkynyl group, a carboxyl group, an acyl halide group, and a (meth)acrylate group. When the first functional group comprises a nucleophilic functional group, the second and third functional groups may comprise an electrophilic functional group. Alternatively, when the first functional group comprises an electrophilic functional group, the second and third functional groups may comprise a nucleophilic functional group.

[0186] In one embodiment, the second and third functional groups may each independently include at least one of an alkenyl group, an alkynyl group, a carboxyl group, an acyl halide group, and a (meth)acrylate group. For example, the second and third functional groups may each independently include any one of an alkenyl group, an alkynyl group, a carboxyl group, an acyl halide group, and a (meth)acrylate group.

[0187] In the quantum dot complex QD-C of one embodiment, the first and second connecting parts CN1 and CN2 included in the first and second ligands LD1 and LD2 can be respectively and independently substituted or unsubstituted divalent alkyl groups with a carbon number of 1 to 30, substituted or unsubstituted divalent alkenyl groups with a carbon number of 2 to 30, substituted or unsubstituted divalent sulfide groups, substituted or unsubstituted divalent oxy groups, substituted or unsubstituted divalent aromatic groups with a ring carbon number of 6 to 60, or substituted or unsubstituted divalent heteroaromatic groups with a ring carbon number of 2 to 60.

[0188] According to one embodiment, a quantum dot complex QD-C may include a scatterer SP and first and second quantum dots QD1 and QD2, and has a structure in which the scatterer SP and the plurality of quantum dots QD1 and QD2 are chemically bonded by a ligand S-LD bound to the scatterer SP and ligands LD1 and LD2 bound to the surfaces of the plurality of quantum dots QD1 and QD2. According to one embodiment, the quantum dot complex QD-C may increase the external quantum efficiency (EQE) by including two quantum dots QD1 and QD2 that emit light of the same color and contain different core materials, compared to a quantum dot complex including a single quantum dot. In addition, according to one embodiment, the quantum dot complex QD-C may improve the dispersibility of the two different quantum dots QD1 and QD2 by having a structure in which the scatterer SP and the first and second quantum dots QD1 and QD2 are connected by the ligands S-LD, LD1, LD2, thereby preventing a decrease in light absorption due to particle aggregation. Furthermore, the first and second quantum dots QD1 and QD2 can be connected via a scatterer SP. Light not absorbed by the first and second quantum dots QD1 and QD2 is scattered by the scatterer SP and readily absorbed by the adjacent first and second quantum dots QD1 and QD2. Thus, a display device including the quantum dot complex QD-C of one embodiment can exhibit high luminous efficiency.

[0189] Figure 6b FIG is a diagram briefly showing the structure of a quantum dot complex according to an embodiment of the present invention. Figure 6b Shown in Figure 6a The quantum dot complex QD-C shown is a quantum dot complex of different embodiments.

[0190] Reference Figure 6b , the quantum dot complex QD-C may include a first scatterer SP1 bound to the surface of a first scatterer ligand S-LD1 chemically bonded to the surface of a first quantum dot QD1, and a second scatterer SP2 bound to the surface of a second scatterer ligand S-LD2 chemically bonded to the surface of a second quantum dot QD2. More specifically, the quantum dot complex QD-C according to one embodiment may include a first sub-quantum dot complex QD-C1 having a structure in which the first scatterer SP1 and the first quantum dot QD1 are connected via a ligand, and a second sub-quantum dot complex QD-C2 having a structure in which the second scatterer SP2 and the second quantum dot QD2 are connected via a ligand.

[0191] The first sub-quantum dot complex QC-C1 may include a first scatterer SP1, a first quantum dot QD1, a first scatterer ligand S-LD1 surface-bound to the first scatterer SP1, and a first ligand LD1 surface-bound to the first quantum dot QD1. In the first sub-quantum dot complex QD-C1, the first scatterer ligand S-LD1 and the first ligand LD1 may be chemically bonded. Through the chemical bonding between the first scatterer ligand S-LD1 and the first ligand LD1, the first scatterer SP1 and the first quantum dot QD1 may be connected.

[0192] The second sub-quantum dot complex QD-C2 may include a second scatterer SP2, a second quantum dot QD2, a second scatterer ligand S-LD2 bound to the surface of the second scatterer SP2, and a second ligand LD2 bound to the surface of the second quantum dot QD2. In the second sub-quantum dot complex QD-C2, the second scatterer ligand S-LD2 and the second ligand LD2 may be chemically bonded. The chemical bonding between the second scatterer ligand S-LD2 and the second ligand LD2 may connect the second scatterer SP2 and the second quantum dot QD2.

[0193] In one embodiment, each of the first and second scatterer ligands S-LD1 and S-LD2 may include a first functional group that can form a chemical bond with the first and second ligands LD1 and LD2. The first scatterer ligand S-LD1 may include one end that is bonded to the first scatterer SP1 and another end that is separated from the first scatterer SP1 and includes a first functional group that can form a chemical bond with the first ligand LD1. For example, Figure 6b As shown, the first scatterer ligand S-LD1 may include a first scatterer head S-HD1 bound to the surface of the first scatterer SP1 and a first scatterer tail S-TL1 separated from the surface of the first scatterer SP1 and containing a first functional group. Furthermore, the first scatterer ligand S-LD1 may also include a first scatterer connector S-CN1 connecting the first scatterer head S-HD1 and the first scatterer tail S-TL1. The second scatterer ligand S-LD2 may include one end bound to the second scatterer SP2 and another end separated from the second scatterer SP2 and containing a first functional group that can form a chemical bond with the second scatterer ligand LD2. The second scatterer ligand S-LD2 may include a second scatterer head S-HD2 bound to the surface of the second scatterer SP2 and a second scatterer tail S-TL2 separated from the surface of the second scatterer SP2 and containing a first functional group. Furthermore, the second scatterer ligand S-LD2 may also include a second scatterer connector S-CN2 connecting the second scatterer head S-HD2 and the second scatterer tail S-TL2. In one embodiment, the first functional group included in the first scatterer ligand S-LD1 and the first functional group included in the second scatterer ligand S-LD2 may be different from or the same as each other.

[0194] On the other hand, regarding the types of the first and second scatterer heads S-HD1 and S-HD2, the same reference can be applied. Figure 6a The description of the scatterer head S-HD is as follows. In addition, the types of the first and second scatterer connecting parts S-CN1 and S-CN2 can be similarly applied to the reference Figure 6a Description of the scatterer connection part S-CN.

[0195] In the quantum dot complex QD-C according to one embodiment, the weight ratio of the first sub-quantum dot complex QD-C1 to the second sub-quantum dot complex QD-C2 may be 1:1 to 2:1. In one embodiment, when the sum of the contents of the first quantum dot QD1, the first ligand LD1, the first scatterer SP1, and the first scatterer ligand S-LD1 is defined as a first weight, and the sum of the contents of the second quantum dot QD2, the second ligand LD2, the second scatterer SP2, and the second scatterer ligand S-LD2 is defined as a second weight, the ratio of the first weight to the second weight may be 1:1 to 2:1. Alternatively, the sum of the contents of the first quantum dot QD1, the first ligand LD1, the first scatterer SP1, and the first scatterer ligand S-LD1 may represent the content of the first sub-quantum dot complex QD-C1, and the sum of the contents of the second quantum dot QD2, the second ligand LD2, the second scatterer SP2, and the second scatterer ligand S-LD2 may represent the content of the second sub-quantum dot complex QD-C2.

[0196] In the quantum dot complex QD-C of one embodiment, the first sub-quantum dot complex QD-C1 may include a first quantum dot QD1, and the first core CR1 included in the first quantum dot QD1 may include a group III-V compound. Alternatively, the second sub-quantum dot complex QD-C2 may include a second quantum dot QD2, and the second core CR2 included in the second quantum dot QD2 may include a group I-III-VI compound. For example, the first core CR1 may include InP, and the second core CR2 may include AgInGaS. When the weight ratio of the first sub-quantum dot complex QD-C1 including the first core CR1 including the group III-V compound and the second sub-quantum dot complex QD-C2 including the second core CR2 including the group I-III-VI compound satisfies a range of 1:1 to 2:1, high external quantum efficiency and high blue light absorptivity may be exhibited, thereby improving the light efficiency of the quantum dot complex QD-C.

[0197] Figure 8 is a cross-sectional view of a display device DD-1 according to another embodiment of the present invention. Figure 8 Shown with Figure 4 The part corresponding to the II-II' line. Figure 8In describing a display device according to an embodiment of the present invention, the same components as those described above are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0198] The display device DD-1 according to this embodiment is different from the reference Figure 5 Compared with the display device DD described above, the difference is that the base layer BL is omitted.

[0199] Reference Figure 8 The display device DD-1 may include a display panel DP and a light control layer PP-1 disposed on the display panel DP. The light control layer PP-1 may include a light conversion layer CCL-1 and a color filter layer CFL-1 disposed on the light conversion layer CCL-1.

[0200] Figure 8 The display device DD-1 shown may include Figure 5 The same display panel DP. The barrier portion BK of the light conversion layer CCL-1 can be configured on the encapsulation layer TFE. The barrier portion BK can be directly configured on the encapsulation layer TFE. Figure 5 Unlike the display device DD shown in FIG. , in a display device DD-1 according to one embodiment, the top surface of the encapsulation layer TFE can be used as a reference surface for configuring the barrier portion BK, the first light control portion CCP-B, the second light control portion CCP-G, and the third light control portion CCP-R. The first light control portion CCP-B, the second light control portion CCP-G, and the third light control portion CCP-R can be respectively configured in the opening of the barrier portion BK.

[0201] A color filter layer CFL-1 is configured on the light conversion layer CCL-1. The color filter layer CFL-1 may include a plurality of filters CF-B, CF-G, CF-R and an overcoat layer OC covering the plurality of filters CF-B, CF-G, CF-R. The color filter layer CFL-1 may include a first filter CF-B overlapping with the first light emitting area PXA-B, a second filter CF-G overlapping with the second light emitting area PXA-G, and a third filter CF-R overlapping with the third light emitting area PXA-R. Figure 8 The color filter layer CFL-1 in the display device DD-1 of the embodiment shown may be connected to the color filter layer CFL-1 included in the display device DD-1. Figure 5 The color filter layer CFL in the display device DD of the illustrated embodiment does not include a light shielding portion BM.

[0202] The first filter CF-B, the second filter CF-G, and the third filter CF-R can define the first light-emitting area PXA-B, the second light-emitting area PXA-G, the third light-emitting area PXA-R, and the peripheral area NPXA. The area where two or more filters among the first filter CF-B, the second filter CF-G, and the third filter CF-R are repeatedly arranged can be defined as the peripheral area NPXA. In each of the first light-emitting area PXA-B, the second light-emitting area PXA-G, and the third light-emitting area PXA-R, only the corresponding filter among the first filter CF-B, the second filter CF-G, and the third filter CF-R is arranged. However, the embodiment is not limited to this. Figure 8 The display device DD-1 of the embodiment shown may also include a light shielding portion BM ( Figure 5 ). A light shielding portion BM ( Figure 5 ), the peripheral area NPXA may also be defined as the area where the light shielding portion BM is configured ( Figure 5 ) area.

[0203] The supercoat layer OC may be an organic layer that protects the plurality of optical filters CF-R, CF-G, and CF-B. The supercoat layer OC may include a photocurable organic material or a thermosetting organic material. However, the present invention is not limited thereto and the supercoat layer OC may also include an inorganic material.

[0204] The color filter layer CFL-1 may further include a buffer layer BFL. The buffer layer BFL may be disposed between the light conversion layer CCL-1 and the plurality of color filters CF-B, CF-G, and CF-R.

[0205] Figure 9a is a cross-sectional view of a display device DD-2 according to yet another embodiment. Figure 9a Shown with Figure 4 The II-II' line corresponds to the part. Figure 9b is a cross-sectional view of a light emitting element according to an embodiment of the present invention.

[0206] Reference Figure 9a The display device DD-2 may include a display panel DP-1 and a light control layer PP disposed on the display panel DP-1. The display panel DP-1 may include a base substrate BS, a circuit layer DP-CL disposed on the base substrate BS, and a display element layer DP-EL-1 disposed on the circuit layer DP-CL.

[0207] The display element layer DP-EL-1 may include a plurality of light-emitting elements ED-1, ED-2, and ED-3 that emit light in different wavelength regions. For example, in one embodiment, the display device DD-2 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, embodiments are not limited thereto; 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 light-emitting element may emit light in a different wavelength region.

[0208] For example, the blue light emitting region PXA-B, the green light emitting region PXA-G, and the red light emitting region PXA-R of the display device DD-2 may correspond to the first light emitting element ED-1, the second light emitting element ED-2, and the third light emitting element ED-3, respectively.

[0209] It can be that the display device DD-2 of one embodiment includes multiple light-emitting elements ED-1, ED-2, and ED-3, and at least any one of the light-emitting elements ED-1, ED-2, and ED-3 includes a light-emitting layer EML-B, EML-G, and EML-R containing a quantum dot complex QD-C1, QD-C2, and QD-C3 according to one embodiment.

[0210] Furthermore, a display device DD-2 according to one embodiment may include a display panel DP-1 including a plurality of light-emitting elements ED-1, ED-2, and ED-3, and a light-control layer PP disposed on the display panel DP-1. Alternatively, unlike the embodiment shown in the accompanying drawings, the light-control layer PP may be omitted from the display device DD-2 according to one embodiment.

[0211] It can be that the display panel DP-1 includes a base substrate BS, a circuit layer DP-CL provided on the base substrate BS, and a display element layer DP-EL-1, the display element layer DP-EL-1 includes a pixel definition film PDL, light-emitting elements ED-1, ED-2, ED-3 arranged between the pixel definition films PDL, and an encapsulation layer TFE arranged on the light-emitting elements ED-1, ED-2, ED-3.

[0212] The first light-emitting layer EML-B of the first light-emitting element ED-1 may include a fourth quantum dot complex QD-C1. The fourth quantum dot complex QD-C1 may emit blue light as the first light.

[0213] The second light-emitting layer EML-G of the second light-emitting element ED-2 and the third light-emitting layer EML-R of the third light-emitting element ED-3 may include a fifth quantum dot complex QD-C2 and a sixth quantum dot complex QD-C3, respectively. The fifth quantum dot complex QD-C2 and the sixth quantum dot complex QD-C3 may emit green light as the second light and red light as the third light, respectively.

[0214] At least one of the fourth to sixth quantum dot complexes QD-C1, QD-C2, and QD-C3 may be the aforementioned quantum dot complex according to one embodiment. In one embodiment, the fifth quantum dot complex QD-C2 may be the aforementioned quantum dot complex according to one embodiment. However, the present invention is not limited thereto, and each of the fourth to sixth quantum dot complexes QD-C1, QD-C2, and QD-C3 may be the aforementioned quantum dot complex according to one embodiment.

[0215] In one embodiment, the fourth to sixth quantum dot complexes QD-C1, QD-C2, and QD-C3 may include quantum dots having different diameters. For example, the fourth quantum dot complex QD-C1 used in the first light-emitting element ED-1 emitting light in a relatively short wavelength region may include quantum dots having a relatively smaller average diameter than the fifth quantum dot complex QD-C2 of the second light-emitting element ED-2 emitting light in a relatively long wavelength region and the sixth quantum dot complex QD-C3 of the third light-emitting element ED-3.

[0216] The relationship between the average diameters of the quantum dots contained in the fourth to sixth quantum dot complexes QD-C1, QD-C2, and QD-C3 is not limited to the above-mentioned limitations. Specifically, the sizes of the quantum dots contained in the fourth to sixth quantum dot complexes QD-C1, QD-C2, and QD-C3 contained in the light-emitting elements ED-1, ED-2, and ED-3 may differ. Furthermore, the average diameters of the quantum dots contained in two selected quantum dot complexes from the fourth to sixth quantum dot complexes QD-C1, QD-C2, and QD-C3 may be similar to each other and different from the average diameters of the quantum dots contained in the remaining quantum dot complexes.

[0217] In addition, the pixel definition layer PDL may be formed of an inorganic material. For example, the pixel definition layer PDL may include silicon nitride (SiN x ), silicon oxide (SiO x ), silicon oxynitride (SiO x N y ) etc. 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 divided from the peripheral region NPXA by the pixel defining film PDL.

[0218] Each of the light-emitting elements ED-1, ED-2, and ED-3 may include a first electrode EL1, a hole transport region HTR, a light-emitting layer EML-B, EML-G, EML-R, an electron transport region ETR, and a second electrode EL2. Except that the quantum dot complexes QD-C1, QD-C2, and QD-C3 included in the light-emitting layers EML-B, EML-G, and EML-R of the light-emitting elements ED-1, ED-2, and ED-3 included in the display device DD of one embodiment are different from each other, the first electrode EL1, the hole transport region HTR, the electron transport region ETR, and the second electrode EL2 may be applied to the method described later. Figure 9b On the other hand, although not shown, each of the light emitting elements ED-1, ED-2, and ED-3 may further include a cover layer between the second electrode EL2 and the encapsulation layer TFE.

[0219] The encapsulation layer TFE may cover the light emitting elements ED-1, ED-2, and ED-3. The encapsulation layer TFE protects the light emitting elements ED-1, ED-2, and ED-3. The encapsulation layer TFE may cover the upper surface of the second electrode EL2 disposed in the opening OH and fill the opening OH.

[0220] On the other hand, Figure 9a The hole transport region HTR and the electron transport region ETR are shown as being provided as a common layer while covering the pixel definition layer PDL, but the embodiment is not limited thereto. In one embodiment, the hole transport region HTR and the electron transport region ETR may be disposed in the opening OH defined in the pixel definition layer PDL.

[0221] For example, when not only the light-emitting layers EML-B, EML-G, and EML-R but also the hole transport region HTR and the electron transport region ETR are provided by an inkjet printing method, the hole transport region HTR, the light-emitting layers EML-B, EML-G, and EML-R, and the electron transport region ETR may be provided corresponding to the opening OH defined between the pixel defining layers PDL. However, the embodiment is not limited thereto, and regardless of the method of providing each functional layer, for example Figure 9a The hole transport region HTR and the electron transport region ETR shown in the figure may not be patterned to cover the pixel defining film PDL and may be provided as a common layer.

[0222] On the other hand, Figure 9aIn the display device DD-2 of the embodiment shown, the thicknesses of 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 are all similar, but the embodiment is not limited thereto. For example, in one embodiment, the thicknesses of 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 can be different from each other.

[0223] The display device DD-2 of one embodiment may further include a light control layer PP. The light control layer PP may block external light provided from outside the display device DD to the display panel DP. The light control layer PP may block a portion of the external light. The light control layer PP may function to prevent reflection by minimizing reflection of the external light. The light control layer PP may include a color filter layer CFL and a base layer BL disposed on the display element layer DP-EL-1. The same methods may be applied to the color filter layer CFL and the base layer BL. Figure 5 The contents described in.

[0224] Figure 9b is a diagram showing a light emitting element ED according to an embodiment, referring to Figure 9b According to an embodiment, the light emitting element ED includes a first electrode EL1, a second electrode EL2 facing the first electrode EL1, and a plurality of functional layers disposed between the first electrode EL1 and the second electrode EL2 and including a light emitting layer EML. Figure 9b The light emitting element ED shown can be used with Figure 9a At least one of the light-emitting elements ED-1, ED-2, and ED-3 shown corresponds.

[0225] The plurality of functional layers may include a hole transport region HTR disposed between the first electrode EL1 and the light emitting layer EML and an electron transport region ETR disposed between the light emitting layer EML and the second electrode EL2. Although not shown in the drawings, in one embodiment, a capping layer may be further disposed on the second electrode EL2.

[0226] The hole transport region HTR and the electron transport region ETR may each include a plurality of sub-functional layers. For example, the hole transport region HTR may include a hole injection layer HIL and a hole transport layer HTL as sub-functional layers, and the electron transport region ETR may include an electron injection layer EIL and an electron transport layer ETL as sub-functional layers. On the other hand, the embodiment is not limited thereto, and the hole transport region HTR may further include an electron blocking layer (not shown) as a sub-functional layer, and the electron transport region ETR may further include a hole blocking layer (not shown) as a sub-functional layer.

[0227] In the light emitting element ED according to an embodiment, the first electrode EL1 has conductivity. The first electrode EL1 may be formed of a metal alloy or a conductive compound. The first electrode EL1 may be an anode or a pixel electrode.

[0228] In the light-emitting element ED according to one embodiment, the first electrode EL1 may be a reflective electrode. However, the embodiment is not limited thereto. For example, the first electrode EL1 may be a transmissive electrode or a semi-transmissive electrode. When the first electrode EL1 is a semi-transmissive or reflective electrode, the first electrode EL1 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture thereof (for example, a mixture of Ag and Mg). Alternatively, the first electrode EL1 may include a multilayer structure including a reflective film or a semi-transmissive film formed from the above-mentioned materials and a transparent conductive film formed from ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), ITZO (indium tin zinc oxide), or the like. For example, the first electrode EL1 may be a multilayer metal film, such as a stacked structure of ITO / Ag / ITO metal films.

[0229] The hole transport region HTR is provided on the first electrode EL1. The hole transport region HTR may include a hole injection layer HIL and a hole transport layer HTL, etc. In addition, the hole transport region HTR may include at least one of a hole buffer layer (not shown) and an electron blocking layer (not shown) in addition to the hole injection layer HIL and the hole transport layer HTL. The hole buffer layer (not shown) can compensate for the resonance distance according to the wavelength of the light emitted from the light-emitting layer EML and increase the light emission efficiency. As a substance contained in the hole buffer layer (not shown), a substance that can be contained in the hole transport region HTR can be used. The electron blocking layer (not shown) is a layer that prevents electron injection from the electron transport region ETR into the hole transport region HTR.

[0230] The hole transport region HTR may have a single layer composed of a single substance, a single layer composed of multiple substances different from each other, or a multilayer structure having multiple layers composed of multiple substances different from each other. For example, the hole transport region HTR may have a single layer structure composed of multiple substances different from each other, or have a structure of hole injection layer HIL / hole transport layer HTL, hole injection layer HIL / hole transport layer HTL / hole buffer layer (not shown), hole injection layer HIL / hole buffer layer (not shown), hole transport layer HTL / hole buffer layer (not shown), or hole injection layer HIL / hole transport layer HTL / electron blocking layer (not shown) stacked in sequence from the first electrode EL1, but the embodiment is not limited thereto.

[0231] The hole transport region HTR can be formed by various methods such as vacuum evaporation, spin coating, casting, Langmuir-Blodgett (LB), inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0232] The hole injection layer HIL may also include, for example, a phthalocyanine compound such as copper phthalocyanine, DNTPD (N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine), m-MTDATA (4,4',4"-[tris(3-methylphenyl)phenylamino]triphenylamine, 4,4',4"-[tris(3-methylphenyl)phenylamino]triphenylamine), TDATA (4,4',4"-Tris(N,N-diphenyl)phenylamino]triphenylamine), or the like. triphenylamine (4,4',4"-tris[N,-(2-naphthyl)-N-phenylamino]-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 / Camphor sulfonicacid, polyaniline / camphorsulfonic acid), PANI / PSS (Polyaniline / Poly(4-styrenesulfonate), polyaniline / poly(4-styrenesulfonate)), NPD (N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine, N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine), polyetherketone containing triphenylamine (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, dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile), etc.

[0233] The hole transport layer HTL may include general materials known in the technical field. For example, the present invention may further include N-phenylcarbazole and / or polyvinylcarbazole carbazole derivatives, fluorene derivatives, TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine), triphenylamine derivatives such as TCTA (4,4',4"-tris(N-carbazolyl)triphenylamine, 4,4',4"-tris(N-carbazolyl)triphenylamine), NPD (N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine, N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine), TAPC (4,4'-Cyclohexylidene bis[N,N-bis(4-methylphenyl)benzenamine], 4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline]), HMTPD(4,4'-Bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl, 4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl), mCP(1,3-Bis(N-carbazolyl)benzene, 1,3-bis(N-carbazolyl)benzene), etc.

[0234] The thickness of the hole transport region HTR may be from about 5 nm to about 1500 nm, for example, from about 10 nm to about 500 nm. The thickness of the hole injection layer HIL may be, for example, from about 3 nm to about 100 nm, and the thickness of the hole transport layer HTL may be from about 3 nm to about 100 nm. For example, the thickness of the electron blocking layer (not shown) may be from about 1 nm to about 100 nm. When the thicknesses of the hole transport region HTR, the hole injection layer HIL, the hole transport layer HTL, and the electron blocking layer (not shown) satisfy the aforementioned ranges, satisfactory hole transport characteristics may be obtained without substantial increase in driving voltage.

[0235] The light emitting layer EML is provided on the hole transport region HTR. The light emitting layer EML may include a quantum dot complex QD-C. The quantum dot complex QD-C included in the light emitting layer EML may include a scatterer SP ( Figure 6a as well as Figure 6b ), the first and second quantum dots QD1, QD2 ( Figure 6a as well as Figure 6b ), the first and second ligands LD1, LD2 ( Figure 6a as well as Figure 6b ) and the scatterer ligand S-LD( Figure 6a as well as Figure 6b ).against Figure 9b The quantum dot complex QD-C contained in the light-emitting layer EML of the light-emitting element ED shown in FIG. Figure 6a as well as Figure 6b The contents described in.

[0236] The light emitting layer EML may include a plurality of quantum dot complexes QD-C. The quantum dot complexes QD-C included in the light emitting layer EML may be stacked to form a layer. Figure 9b Schematically, the quantum dot complexes QD-C having a circular cross-section are arranged to generally form two layers, but the embodiment is not limited thereto. For example, the arrangement of the quantum dot complexes QD-C may vary depending on the thickness of the light-emitting layer EML, the shape of the quantum dot complexes QD-C contained in the light-emitting layer EML, the average diameter of the scatterers and quantum dots contained in the quantum dot complexes QD-C, the type of ligand contained in the quantum dot complexes QD-C, etc. Specifically, the quantum dot complexes QD-C in the light-emitting layer EML may be arranged adjacent to each other to form a single layer, or may be arranged to form multiple layers such as two or three layers.

[0237] The maximum emission wavelength range of the light-emitting layer (EML) may be between approximately 510 nm and approximately 550 nm. The light-emitting layer (EML) may emit green light having a wavelength between approximately 510 nm and approximately 550 nm. However, the light-emitting layer (EML) is not limited thereto and may emit blue light or red light. The center wavelength of light emission of the light-emitting layer (EML) may be between approximately 430 nm and approximately 490 nm. Alternatively, the center wavelength of light emission of the light-emitting layer (EML) may be between approximately 590 nm and approximately 650 nm.

[0238] In one embodiment, the light-emitting layer EML of the light-emitting element ED may include a host and a dopant. In one embodiment, the light-emitting layer EML may include quantum dots QD as a dopant material. In one embodiment, the light-emitting layer EML may further include a host material.

[0239] On the other hand, in the light-emitting element ED of one embodiment, the light-emitting layer EML can emit fluorescent light. For example, a quantum dot complex QD-C can be used as a fluorescent dopant material.

[0240] In one embodiment, the electron transport region ETR is provided on the light emitting layer EML in the light emitting element ED. The electron transport region ETR may include at least one of a hole blocking layer (not shown), an electron transport layer ETL, and an electron injection layer EIL, but the embodiment is not limited thereto.

[0241] The electron transport region ETR may have a single layer composed of a single substance, a single layer composed of a plurality of substances different from each other, or a multilayer structure having a plurality of layers composed of a plurality of substances different from each other.

[0242] For example, the electron transport region ETR may also have a single-layer structure of an electron injection layer EIL or an electron transport layer ETL, or may have a single-layer structure composed of an electron injection material and an electron transport material. In addition, the electron transport region ETR may have a single-layer structure composed of a plurality of different substances, or have an electron transport layer ETL / electron injection layer EIL, a hole blocking layer (not shown) / electron transport layer ETL / electron injection layer EIL structure stacked in sequence from the light-emitting layer EML, but is not limited thereto. The thickness of the electron transport region ETR may be, for example, about 20 nm to about 150 nm.

[0243] The electron transport region ETR can be formed by various methods such as vacuum evaporation, spin coating, casting, Langmuir-Blodgett (LB), inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0244] In the case where the electron transport region ETR includes the electron transport layer ETL, the electron transport region ETR may include an anthracene-based compound.However, the electron transport region is not limited thereto, and may include Alq3 (Tris(8-hydroxyquinolinato)aluminum, tris(8-hydroxyquinolinato)aluminum), 1,3,5-tris[(3-pyridyl)-phenyl-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, DPEPO (bis[2-(diphenylphosphino)phenyl]etheroxide, bis[2-((oxy)diphenylphosphino)phenyl]ether), 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, TPBi(1,3,5-Tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl, 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene), BCP(2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen( 4,7-Diphenyl-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline), TAZ (3-(4-Biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole, 3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), NTAZ (4-(Naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazol e, 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, 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq(Bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-Biphenyl-4-olato)aluminu m, bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum), Bebq2(berylliumbis(benzoquinolin-10-olate, bis(10-hydroxybenzoquinolinyl)beryllium), AND(9,10-di(naphthalene-2-yl)anthracene, 9,10-di(naphthalene-2-yl)anthracene) or a mixture thereof.The thickness of the electron transport layer (ETL) may be about 10 nm to about 100 nm, for example, about 15 nm to about 50 nm. When the thickness of the electron transport layer (ETL) satisfies the aforementioned range, satisfactory electron transport characteristics may be obtained without a substantial increase in driving voltage.

[0245] In the case where the electron transport region ETR includes an electron injection layer EIL, the electron transport region ETR can use a metal halide such as LiF, NaCl, CsF, RbCl, RbI, a lanthanide metal such as Yb, a metal oxide such as Li2O, BaO, or LiQ (Lithium quinolate, lithium quinolate), but is not limited thereto. The electron injection layer EIL can also be composed of a substance mixed with an electron transport material and an insulating organic metal salt. For example, the organic metal salt can include metal acetate, metal benzoate, metal acetoacetate, metal acetylacetonate, or metal stearate. The thickness of the electron injection layer EIL can be about 0.1 nm to about 10 nm, about 0.3 nm to about 9 nm. When the thickness of the electron injection layer EIL meets the above range, satisfactory electron injection characteristics can be obtained without a substantial increase in driving voltage.

[0246] The electron transport region (ETR) may include a hole blocking layer (not shown) as mentioned above. The hole blocking layer (not shown) may include, for example, at least one of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and Bphen (4,7-diphenyl-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline), but is not limited thereto.

[0247] The second electrode EL2 is provided on the electron transport region ETR. The second electrode EL2 may be a common electrode or a cathode. The second electrode EL2 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. When the second electrode EL2 is a transmissive electrode, the second electrode EL2 may be formed of a transparent metal oxide (e.g., ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), ITZO (indium tin zinc oxide), etc.).

[0248] When the second electrode EL2 is a semi-transmissive electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, Yb, and W, or a compound or mixture thereof (for example, AgMg, AgYb, or MgYb). Alternatively, the second electrode EL2 may include a multilayer structure including a reflective film or a semi-transmissive film formed of the above substances and a transparent conductive film formed of ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), ITZO (indium tin zinc oxide), or the like.

[0249] Although not shown, the second electrode EL2 may be connected to an auxiliary electrode. In the case where the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0250] Figure 10 is a sequence diagram illustrating a method for preparing a quantum dot composition according to one embodiment of the present invention.

[0251] Reference Figure 10 According to one embodiment, a method for preparing a quantum dot composition includes providing a first quantum dot having a first ligand bound to the surface and including a first core, and a second quantum dot having a second ligand bound to the surface and including a second core (S100), providing a scatterer having a scatterer ligand bound to the surface (S200), mixing the first quantum dot having the first ligand bound to the first quantum dot and the second quantum dot having the second ligand bound to the scatterer having the scatterer ligand bound to provide a preliminary quantum dot composition (S300), and providing heat or light to the preliminary quantum dot composition to chemically bond the scatterer ligand to each of the first ligand and the second ligand (S400).

[0252] Figure 11 、 Figure 12a as well as Figure 12b 1 is a cross-sectional view showing a portion of the steps in the method for preparing a quantum dot composition according to an embodiment of the present invention. Figure 11 、 Figure 12a as well as Figure 12b When describing a method for preparing a quantum dot composition according to an embodiment, the same structures as those described above are given the same reference numerals and detailed descriptions are omitted.

[0253] Reference Figure 11, a first quantum dot QD1 having a first ligand LD1 bound to the surface and a second quantum dot QD2 having a second ligand LD2 bound to the surface can be provided. The first quantum dot QD1 and the second quantum dot QD2 can include cores different from each other. It can be that the first quantum dot QD1 includes a first core CR1, and the second quantum dot QD2 includes a second core CR2 different from the first core CR1. Figure 11 As shown, the first quantum dot QD1 may include a first shell SL1 covering a first core CR1, and the first ligand LD1 may be bonded to the surface of the first shell SL1. Alternatively, the second quantum dot QD2 may include a second shell SL2 covering a second core CR2, and the second ligand LD2 may be bonded to the surface of the second shell SL2.

[0254] The scatterer SP may be provided in a state where the scatterer ligand S-LD is bonded to the surface. The scatterer SP may be provided in a state where the surface is modified by the scatterer ligand S-LD.

[0255] like Figure 11 As shown, the first quantum dot QD1 having the first ligand LD1 bound to the surface and the second quantum dot QD2 having the second ligand LD2 bound to the surface can be mixed with the scatterer SP having the scatterer ligand S-LD bound to the surface to provide a preliminary quantum dot composition QCP-P. Although not shown, the preliminary quantum dot composition QCP-P may further include a solvent for dispersing the first quantum dot QD1, the second quantum dot QD2, and the scatterer SP.

[0256] Energy E can be applied to the preliminary quantum dot composition QCP-P to chemically bond the first and second ligands LD1 and LD2 to the scatterer ligand S-LD. For example, heat or light can be applied to the preliminary quantum dot composition QCP-P to chemically bond the first and second ligands LD1 and LD2 to the scatterer ligand S-LD. The heat or light can cause the first functional group of the scatterer ligand S-LD to react with the second functional group of the first ligand LD1 to form a chemical bond. Furthermore, the heat or light can cause the first functional group of the scatterer ligand S-LD to react with the third functional group of the second ligand LD2 to form a chemical bond.

[0257] Figure 12a as well as Figure 12b FIG. 1 is a diagram illustrating the reaction steps of the scatterer ligand S-LD and the first and second ligands LD1 and LD2 in a quantum dot composition according to one embodiment.

[0258] exist Figure 12a as well as Figure 12b FIG2 exemplarily shows the steps of chemically bonding the scatterer ligand S-LD to each of the first ligand LD1 and the second ligand LD2 in a method for preparing a quantum dot composition according to an embodiment. Figure 12a as well as Figure 12b exemplarily shows that the scatterer ligand S-LD includes a thiol group as a first functional group, the first ligand LD1 includes an acrylate group as a second functional group, and the second ligand LD2 includes an acrylate group as a third functional group.

[0259] The first functional group contained in the scatterer ligand S-LD can react with the second functional group contained in the first ligand LD1 to form a chemical bond. Figure 12a as well as Figure 12b As shown, the thiol group as the first functional group contained in the scatterer ligand S-LD can react with the acrylate group as the second functional group contained in the first ligand LD1 to form a chemical bond. In addition, the first functional group contained in the scatterer ligand S-LD can react with the third functional group contained in the second ligand LD2 to form a chemical bond. Figure 12a as well as Figure 12b As shown, the thiol group as the first functional group included in the scatterer ligand S-LD may react with the acrylate group as the third functional group included in the second ligand LD2 to form a chemical bond.

[0260] In one embodiment, chemical bonding can be formed by the mechanism shown in the following reaction formula 1. The following reaction formula 1 exemplifies the chemical bonding formed by the reaction of the scatterer ligand S-LD and the first ligand LD1. The mechanism for forming a chemical bond by the reaction of the scatterer ligand S-LD and the second ligand LD2 can also be similarly applied to the content described in the following reaction formula 1.

[0261] [Reaction formula 1]

[0262]

[0263] In reaction formula 1, L SH Corresponding to the scatterer head S-HD of the scatterer ligand S-LD, L SC The "-*" indicates the position of connection with the scatterer SP. In addition, in reaction formula 1, L H1 Corresponding to the first head HD1 of the first ligand LD1, L C1 Corresponding to the first connecting portion CN1 of the first ligand LD1. It means the position connected to the first quantum dot QD1.

[0264] Reference Figure 12a 、 Figure 12bAs shown in Reaction Formula 1, a thiyl radical can be formed from the thiol group contained in the scatterer ligand S-LD by light hv provided to the prepared quantum dot composition QCP-P. The formed thiyl radical can react with the carbon-carbon unsaturated bond contained in the first ligand LD1. A vinyl radical having a new "sulfur-carbon" bond can be formed by the reaction of the thiol radical and the carbon-carbon unsaturated bond, and then the vinyl radical can terminate the reaction by taking a hydrogen atom from a different thiol group. On the other hand, Reaction Formula 1 exemplarily shows that the scatterer ligand S-LD and the first ligand LD1 form a chemical bond through a radical addition reaction, but the embodiment is not limited thereto. The chemical bond between the scatterer ligand S-LD and the first ligand LD1 can also be formed through a nucleophilic addition reaction or a nucleophilic substitution reaction according to the type of functional group and the reaction conditions.

[0265] Figure 13 is a sequence diagram illustrating a method for preparing a quantum dot composition according to one embodiment of the present invention. Figure 14a as well as Figure 14b 1 is a diagram illustrating some steps in a method for preparing a quantum dot composition according to an embodiment of the present invention. Figure 13 、 Figure 14a as well as Figure 14b is shown with Figures 10 to 12b The following is a diagram of a method for preparing a quantum dot composition according to an embodiment of the present invention. Figure 13 、 Figure 14a as well as Figure 14b , a method for preparing a quantum dot composition according to an embodiment is described in detail. Figures 10 to 12b The same contents will not be explained again, and the explanation will be based on the differences.

[0266] Reference Figure 13 According to one embodiment, the method for preparing a quantum dot composition includes the steps of providing a first quantum dot having a first ligand bound to the surface and including a first core, and a second quantum dot having a second ligand bound to the surface and including a second core (S100), providing a scatterer having a scatterer ligand bound to the surface (S200), mixing the first quantum dot having the first ligand bound to the scatterer having the scatterer ligand bound to provide a first preliminary quantum dot composition (S300a), mixing the second quantum dot having the second ligand bound to the scatterer having the scatterer ligand bound to provide a second preliminary quantum dot composition (S300b), providing heat or light to the first preliminary quantum dot composition and the second preliminary quantum dot composition (S400a), and mixing the first preliminary quantum dot composition provided with heat or light with the second preliminary quantum dot composition (S500). That is, Figure 13 、 Figure 14a as well as Figure 14bThe method for preparing a quantum dot composition according to one embodiment is shown in FIG. Figures 10 to 12b Different from the method of preparing a quantum dot composition described above, a first prepared quantum dot composition in which a first quantum dot and a scatterer are mixed and a second prepared quantum dot composition in which a second quantum dot and a scatterer are mixed can be provided by separate processes, and then heat or light can be provided to each of the first prepared quantum dot composition and the second prepared quantum dot composition to form chemical bonds between ligands.

[0267] Reference Figure 13 as well as Figure 14a , a method for preparing a quantum dot composition of an embodiment may include the step of providing a first preliminary quantum dot composition. The step of providing the first preliminary quantum dot composition (S300a) may be a step of mixing the first quantum dot QD1 having the first ligand LD1 bound to the surface and the first scatterer SP1 having the first scatterer ligand S-LD1 bound to the surface. In the first preliminary quantum dot composition QCP1-P, the first quantum dot QD1 may be provided in a state of being surface-modified by the first ligand LD1. In addition, in the first preliminary quantum dot composition QCP1-P, the first scatterer SP1 may be provided in a state of being surface-modified by the first scatterer ligand S-LD1. Although not shown in the figure, the first preliminary quantum dot composition QCP1-P may further include a solvent for dispersing the first quantum dot QD1 and the first scatterer SP1.

[0268] Energy E can be applied to the first preliminary quantum dot composition QCP1-P to chemically bond the first ligand LD1 and the first scatterer ligand S-LD1. For example, heat or light can be applied to the first preliminary quantum dot composition QCP1-P to chemically bond the first ligand LD1 and the first scatterer ligand S-LD1. The heat or light can cause the first functional group of the first scatterer ligand S-LD1 and the second functional group of the first ligand LD1 to react to form a chemical bond. The mechanism by which the first ligand LD1 and the first scatterer ligand S-LD1 react to form a chemical bond can be similarly applied to the mechanism described in Reaction Formula 1 above.

[0269] Reference Figure 13 as well as Figure 14b, the method for preparing a quantum dot composition of one embodiment may include the step of providing a second preliminary quantum dot composition. The step of providing the second preliminary quantum dot composition (S300b) may be a step of mixing the second quantum dots QD2 having the second ligand LD2 bound to the surface and the second scatterer SP2 having the second scatterer ligand S-LD2 bound to the surface. In the second preliminary quantum dot composition QCP2-P, the second quantum dots QD2 may be provided in a state of being surface-modified by the second ligand LD2. In addition, in the second preliminary quantum dot composition QCP2-P, the second scatterer SP2 may be provided in a state of being surface-modified by the second scatterer ligand S-LD2. Although not shown in the figure, the second preliminary quantum dot composition QCP2-P may further include a solvent for dispersing the second quantum dots QD2 and the second scatterer SP2.

[0270] Energy E can be applied to the second preliminary quantum dot composition QCP2-P to chemically bond the second ligand LD2 and the second scatterer ligand S-LD2. For example, heat or light can be applied to the second preliminary quantum dot composition QCP2-P to chemically bond the second ligand LD2 and the second scatterer ligand S-LD2. The heat or light can cause the first functional group of the second scatterer ligand S-LD2 and the third functional group of the second ligand LD2 to react, forming a chemical bond. The mechanism by which the second ligand LD2 and the second scatterer ligand S-LD2 react to form a chemical bond can be similarly applied to the mechanism described in Reaction Formula 1 above.

[0271] Thereafter, a step of mixing the first preliminary quantum dot composition QCP1-P provided with heat or light and the second preliminary quantum dot composition QCP2-P provided with heat or light may be performed. Figure 13 、 Figure 14a as well as Figure 14b The quantum dot preparation method described can be used to prepare Figure 6b The quantum dot compositions of the quantum dot complexes QD-C1 and QD-C2 are shown.

[0272] Figure 15a is a sequence diagram illustrating a method for manufacturing a display device according to an embodiment of the present invention. Figure 15b FIG. 1 is a sequence diagram for subdividing the steps of forming a light conversion layer according to an embodiment of the present invention.

[0273] Reference Figure 15a A method for manufacturing a display device according to an embodiment includes a step of preparing a display panel (SS100) and a step of forming a light conversion layer (SS200).

[0274] Reference Figure 15bAccording to one embodiment, the step of forming a light conversion layer (SS200) includes providing a quantum dot composition to form a preliminary light control unit (SS201) and curing the preliminary light control unit (SS202). Figures 1 to 5 as well as Figure 8 In the display device DD, DD-1 of the aforementioned embodiment, at least one of the light control parts CCP-B, CCP-G, and CCP-R included in the light conversion layer CCL can be formed by the step of forming the light conversion layer to be described later.

[0275] Figures 16a to 16c 1 is a cross-sectional view showing some steps in a method for manufacturing a display device according to an embodiment of the present invention. Figures 16a to 16c The steps of forming the light conversion layer in the method for manufacturing a display device according to an embodiment of the present invention are shown in sequence. Figures 16a to 16c In describing a method for manufacturing a display device according to an embodiment, the same structures as those described above are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0276] A method for manufacturing a display device according to an embodiment of the present invention includes preparing a display panel and forming a light conversion layer on the display panel.

[0277] Reference Figure 16a In the method for manufacturing a display device according to an embodiment, the step of forming a light conversion layer includes providing a quantum dot composition QCP on a reference surface to form a light control portion CCP ( Figure 16c ) steps. Figure 16a The quantum dot composition QCP shown can be obtained by referring to Figures 10 to 12b The quantum dot composition prepared by the quantum dot preparation method described. In addition, Figure 16a The quantum dot composition QCP shown can be obtained by referring to Figures 13 to 14b The quantum dot preparation method is described to prepare a quantum dot composition.

[0278] The method of providing the quantum dot composition QCP on the reference surface is not particularly limited, and methods such as spin coating, casting, LB (Langmuir-Blodgett), inkjet printing, laser printing, and laser thermal transfer (Laser Induced Thermal Imaging, LITI) can be used. Figure 16a , the quantum dot composition QCP is coated on the reference surface through the nozzle NZ, but is not limited thereto. The quantum dot composition QCP can be provided on the reference surface by various methods.

[0279] In addition, Figures 16a to 16cThe structure in which the reference surface coated with the quantum dot composition QCP is provided is exemplarily shown as the display element layer DP-EL, but is not limited thereto. The quantum dot composition QCP may be coated on the display element layer DP-EL included in the light control layer PP ( Figure 5 ) in the functional layer (eg, the base layer BL ( Figure 5 ) or color filter layer CFL( Figure 5 ) etc.). In addition, the manufacturing method of the display device of one embodiment may further include the step of patterning a plurality of barrier portions BK on the reference surface before coating the quantum dot composition QCP. For example, Figure 16a In the case where the structure providing the reference surface is the display element layer DP-EL, before coating the quantum dot composition QCP, the method may further include patterning a plurality of barrier portions BK on the display element layer DP-EL.

[0280] The quantum dot composition QCP can be dripped between the plurality of barrier portions BK. The quantum dot composition QCP can include a matrix resin SV and a quantum dot complex QD-C dispersed in the matrix resin SV. For the quantum dot complex QD-C included in the quantum dot composition QCP, the same reference can be applied. Figure 6a as well as Figure 6b etc. for the description of quantum dot complexes.

[0281] The matrix resin SV may include acrylic resin, methacrylic resin, urethane resin, fluorine resin, epoxy resin, vinyl resin, polyester resin, polyamide resin, polyimide resin, cellulose resin, polyparaxylene resin, silicone resin, or a combination thereof.

[0282] The quantum dot composition (QCP) of one embodiment may further include additional additives as needed. These additives may be appropriately selected from conventional additives known in the art to adjust the desired physical properties of the quantum dot composition (QCP). Examples include, but are not limited to, dispersants, light stabilizers, crosslinkers, antioxidants, chain transfer agents, photosensitizers, inhibitors, leveling agents, surfactants, adhesion agents, plasticizers, UV absorbers, storage stabilizers, antistatic agents, inorganic fillers, pigments, or dyes. These additives may be used alone or in combination of two or more.

[0283] The quantum dot composition QCP of one embodiment may further include an initiator. In this specification, an initiator may refer to a compound that can initiate free radical polymerization by heat or light. The initiator may be a thermal initiator or a photoinitiator.

[0284] The quantum dot composition QCP of one embodiment may include a thermal initiator. An example of the thermal initiator may be azobisisobutyronitrile, but the invention is not limited thereto.

[0285] The quantum dot composition (QCP) of one embodiment may include a photoinitiator. The photoinitiator may include, but is not limited to, a triazine compound, an acetophenone compound, a benzophenone compound, a thioxanthone compound, a benzoin compound, an oxime ester compound, an aminoketone compound, a phosphine or phosphine oxide compound, a carbazole compound, a diketone compound, a sulfonium borate compound, a diazo compound, a biimidazole compound, or a combination thereof. If the quantum dot composition (QCP) includes multiple photoinitiators, the different photoinitiators may be activated by ultraviolet light having different central wavelengths.

[0286] For example, the photoinitiator can be 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl- Any one selected from 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methylpropan-1-one.

[0287] Alternatively, the photoinitiator may be 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-dimethylamino-2-(4-methyl-benzyl)- 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, 2,4,6-trimethylbenzoyl-diphenylphosphineoxide, 2,4,6-trimethylbenzoyl-diphenylphosphinate, bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide, [1-(4-phenylsulfanylbenzoyl)heptylideneamino]benzoate, [1-[9-ethyl-6-(2-methylbenzoyl)carbazole-3-yl]-thiazolyl]-piperidinyl]-1-one]-1-(4-morpholin-4-yl-phenyl)-butan-1-one] Any one selected from [1-[9-ethyl-6-(2-methylbenzoyl)carbazol-3-yl]ethylideneamino]acetate and Bis(2,4-cyclopentadienyl)bis[2,6-difluoro-3-(1-pyrryl)phenyl]titanium(IV).

[0288] The quantum dot composition QCP may further include a solvent. During the step of forming the light control portion CCP, the solvent may be removed. However, the invention is not limited thereto, and a portion of the solvent may also remain in the light control portion CCP.

[0289] The solvent may be an organic solvent or an inorganic solvent such as water. The organic solvent may include hexane, toluene, chloroform, dimethyl sulfoxide, octane, xylene, hexadecane, cyclohexylbenzene, triethylene glycol monobutyl ether or dimethyl formamide, decane, dodecane, hexadecane, cyclohexylbenzene, triethylene glycol monobutyl ether, dimethyl formamide, decane, dodecane, hexadecane, cyclohexylbenzene, cyclohexylbenzene, triethylene glycol monobutyl ether, dimethyl formamide, decane, dodecane, hexadecane, cyclohexylbenzene, cyclohexylbenzene, cyclohexylbenzene, triethylene glycol monobutyl ether, dimethyl formamide, decane, dodecane, cyclohexylbenzene ... Hexadecene), Tetrahydronaphthalene, Ethylnaphthalene, Ethylbiphenyl, Isopropylnaphthalene, Diisopropylnaphthalene, Diisopropylbiphenyl, Xylene, IsoPropylbenzene, Pentylbenznene, Diisopropylbenzene, Decahedron The present invention also includes, but is not limited to, cyclohexane, cyclopentane, cycloheptane, methanol, ethanol, propanol, isopropanol, ethylene glycol, propylene glycol, diethylene glycol, and the like.

[0290] In one embodiment, based on the total content of the quantum dot composition QCP being 100 wt %, the first quantum dot QD1 ( Figure 6a as well as Figure 6b ) and the content of the second quantum dot QD2( Figure 6a as well as Figure 6b ) can be less than 38 wt%. For example, the first quantum dot QD1 ( Figure 6a as well as Figure 6b ) and the content of the second quantum dot QD2( Figure 6a as well as Figure 6b The sum of the contents of the first quantum dot QD1 ( Figure 6a as well as Figure 6b ) and the content of the second quantum dot QD2( Figure 6a as well as Figure 6b ) satisfies the aforementioned range, the solution processability of the composition can be improved while fully maintaining the luminous efficiency of the light control part CCP formed later.

[0291] In one embodiment, based on the total content of the quantum dot composition QCP being 100 wt %, the scatterer SP ( Figure 6a as well as Figure 6b ) can be more than 2 wt% and less than 8 wt%. Figure 6a as well as Figure 6b ) is less than 2 wt %, the first and second quantum dots QD1, QD2 ( Figure 6a as well as Figure 6b ) is less dispersible and light absorption decreases due to particle aggregation. Figure 6a as well as Figure 6b ) content exceeds 8 wt %, the viscosity of the quantum dot composition QCP may be excessively increased, thereby reducing solution processability.

[0292] Reference Figure 16a as well as Figure 16b The quantum dot composition QCP may form a preliminary light control portion P-CCP. The preliminary light control portion P-CCP formed by the quantum dot composition QCP may include a matrix resin SV and a quantum dot complex QD-C dispersed in the matrix resin SV.

[0293] Figure 16b The present invention briefly illustrates the step of curing the preliminary light control portion P-CCP in the method for manufacturing a display device according to one embodiment (SS202, Figure 15b ). According to an embodiment, the step of curing the preliminary light control part P-CCP may include the step of providing heat or light to the preliminary light control part P-CCP. Figure 16b exemplarily illustrates that the light UV is provided to the preliminary light control part P-CCP, but the embodiment is not limited thereto.

[0294] Reference Figure 16b as well as Figure 16c, the preliminary light control part P-CCP can be cured to form the light control part CCP. The light control part CCP can include a quantum dot complex QD-C. The quantum dot complex QD-C can be included in the light control part CCP finally manufactured. Figure 16a ) formed by the light control unit CCP display device DD ( Figure 2 ) can exhibit enhanced luminescence properties.

[0295] On the other hand, although not shown in the figures, the display device manufacturing method according to one embodiment may further include a step of heat-treating (baking) the preliminary light control part P-CCP after the step of curing the preliminary light control part P-CCP. The step of heat-treating the preliminary light control part P-CCP may be a step of providing heat at a temperature of 50°C or above to the preliminary light control part P-CCP. The heat treatment may remove solvents contained in the preliminary light control part P-CCP, etc. For example, the step of heat-treating the preliminary light control part P-CCP may be a step of providing heat at a temperature of 100°C or above to remove solvents contained in the preliminary light control part P-CCP.

[0296] On the other hand, although not shown, Figure 9a At least one of the light emitting elements ED-1, ED-2, and ED-3 can be formed by the same method as the method for forming the aforementioned light conversion layer. Figure 9b The light emitting element ED shown can be formed by the same method as the method of forming the light conversion layer. Figure 9b The method for forming the light emitting element ED may include forming a hole transport region HTR on the first electrode EL1, forming a light emitting layer EML on the hole transport region HTR, forming an electron transport region ETR on the light emitting layer EML, and forming a second electrode EL2 on the electron transport region ETR. The step of forming the light emitting layer EML may include forming a hole transport region HTR on the first electrode EL1, forming a light emitting layer EML on the hole transport region HTR, forming an electron transport region ETR on the light emitting layer EML, and forming a second electrode EL2 on the electron transport region ETR. Figure 16a The steps of providing the quantum dot composition QCP to form a preliminary luminescent layer and curing the preliminary luminescent layer are as follows. Figures 16a to 16c The contents described in the step of forming the preliminary light control portion and the step of curing the preliminary light control portion.

[0297] Hereinafter, a quantum dot composition according to an embodiment of the present invention will be specifically described with reference to examples and comparative examples. The following examples are provided to facilitate understanding of the present invention and are not intended to limit the scope of the present invention.

[0298] [Example]

[0299] 1. Preparation of Quantum Dot Compositions

[0300] 1) Quantum dot composition 1

[0301] (InP / ZnSeS quantum dot synthesis)

[0302] Indium acetate (10 mmol), zinc acetate (5 mmol), and stearic acid (50 mmol) were mixed with 1-octadecene (50 mL) as a solvent and heated at 120°C for 2 hours under vacuum to prepare a precursor solution. Tris(trimethylsilyl)phosphine (5 mmol) was added to the precursor solution at room temperature under a nitrogen atmosphere and heated at 300°C for 2 minutes. The temperature was then lowered to prepare InP nuclei.

[0303] The InP core was purified using a mixed solution of toluene and acetone. Zinc oleate (12.6 mmol), trioctylphosphine selenide (10.2 mmol), trioctylphosphine sulfide (8 mmol), and trioctylamine were placed into the core dispersed in toluene, and then reacted at above 320°C for 1 hour to form a ZnSeS (zinc selenide / sulfide) shell, thereby synthesizing InP / ZnSeS quantum dots.

[0304] (AIGS / GaS quantum dot synthesis)

[0305] Indium iodide (4 mmol), gallium iodide (4 mmol), and silver acetate (2.25 mmol) were mixed with oleylamine (50 mL) and heated at 120°C for 2 hours under vacuum to prepare a precursor solution. Dodecane thiol (16 mmol) was added to the solution, and the temperature was raised to 200°C under a nitrogen atmosphere for 20 minutes. The reaction was terminated by the addition of 10 mL of trioctylphosphine to prepare AIGS nuclei.

[0306] The AIGS cores were purified using a mixed solution of toluene and acetone, then placed in 50 mL of gallium chloride (3 mmol), dodecanethiol (9 mmol), and oleylamine, and dissolved under vacuum at 80°C for 1 hour. The AIGS cores, redispersed in toluene, were then added and heated to 280°C to form a GaS (gallium sulfide) shell, thereby synthesizing AIGS / GaS quantum dots.

[0307] (Quantum dot-ligand binding formation)

[0308] The InP / ZnSeS quantum dots synthesized in the above process were dissolved in cyclohexyl acetate at 34% by weight. MAS (mono-2-(Acryloyloxy)ethyl succinate) was added at 20% by weight relative to the quantum dots and heated at 70°C for 1 hour. The reaction mixture was then purified using hexane and powdered to produce ligand-bound InP / ZnSeS quantum dots. Separately, ligand-bound AIGS / GaS quantum dots were synthesized using the same method as described above.

[0309] (Preparation of Quantum Dot Complexes)

[0310] A first preliminary quantum dot composition was prepared by mixing ligand-bound quantum dots (InP / ZnSeS) and scatterer ligand-bound TiO2 at a weight ratio of 36:8. The first preliminary quantum dot composition was irradiated with 15 J of 365 nm ultraviolet light to form chemical bonds between the quantum dot ligands bound to the surfaces of the InP / ZnSeS quantum dots and the scatterer ligands bound to the surface of the TiO2 scatterer, thereby producing a first sub-quantum dot complex.

[0311] The second sub-quantum dot complex can be prepared using the same method as the first sub-quantum dot complex. Specifically, a second preliminary quantum dot composition is prepared by mixing ligand-bound AgInGaS / GaS and scatterer ligand-bound TiO2 at a weight ratio of 36:8. This second preliminary quantum dot composition is then irradiated with 15 J of 365 nm ultraviolet light to form chemical bonds between the quantum dot ligands bound to the AgInGaS / GaS quantum dots and the scatterer ligands bound to the TiO2 scatterer, thereby preparing the second sub-quantum dot complex.

[0312] On the other hand, the scatterer ligand used in Examples and Comparative Examples used a thiol (polyethylene glycol) carboxylic acid having the following structure S1: In the following structure S1, m is 12.

[0313]

[0314] (Quantum Dot Composition Preparation)

[0315] The first and second sub-quantum dot complexes prepared in the quantum dot complex preparation step were mixed at a weight ratio of 1:1 to prepare a quantum dot complex. Subsequently, 44 weight percent of the purified quantum dot complex, 54 weight percent of 1,6-hexanediol diacrylate (HDDA), and 1 weight percent of an initiator, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, were mixed to prepare a quantum dot composition.

[0316] 2) Quantum dot composition 2

[0317] A quantum dot composition was prepared by the same method as the quantum dot composition 1, except that the weight ratio of the first sub-quantum dot complex to the second sub-quantum dot complex was set to 2:1.

[0318] 3) Quantum dot composition 3

[0319] A quantum dot composition was prepared by the same method as the quantum dot composition 1, except that the weight ratio of the first sub-quantum dot complex to the second sub-quantum dot complex was set to 3:1.

[0320] 4) Quantum dot composition 4

[0321] A quantum dot composition was prepared by the same method as the quantum dot composition 1, except that the weight ratio of the first sub-quantum dot complex to the second sub-quantum dot complex was set to 1:2.

[0322] 5) Quantum dot composition 5

[0323] A quantum dot composition was prepared by the same method as the quantum dot composition 1, except that the weight ratio of the first sub-quantum dot complex to the second sub-quantum dot complex was set to 1:3.

[0324] 6) Comparison of quantum dot composition 1

[0325] A quantum dot composition was prepared by the same method as that of quantum dot composition 1, except that a single InP / ZnSeS quantum dot was used instead of two quantum dots and the light irradiation step was omitted. That is, comparative quantum dot composition 1 contained a single InP / ZnSeS quantum dot and corresponded to a structure having TiO2 and InP / ZnSeS quantum dots that were not chemically bonded by ligands.

[0326] 7) Comparison of quantum dot composition 2

[0327] A quantum dot composition was prepared by the same method as that of quantum dot composition 1, except that a single InP / ZnSeS quantum dot was used instead of two quantum dots. That is, comparative quantum dot composition 2 contained a single InP / ZnSeS quantum dot and corresponded to a structure having TiO2 and InP / ZnSeS quantum dots connected by ligand chemical bonds.

[0328] 8) Comparison of quantum dot composition 3

[0329] A quantum dot composition was prepared by the same method as that of quantum dot composition 1, except that a single AgInGaS / GaS quantum dot was used instead of the two quantum dots and the light irradiation step was omitted. That is, comparative quantum dot composition 3 contained a single AgInGaS / GaS quantum dot and corresponded to a structure having TiO2 and AgInGaS / GaS quantum dots that were not chemically bonded by ligands.

[0330] 9) Comparison of quantum dot compositions 4

[0331] A quantum dot composition was prepared by the same method as that of quantum dot composition 1, except that a single AgInGaS / GaS quantum dot was used instead of two quantum dots. That is, comparative quantum dot composition 4 contained a single AgInGaS / GaS quantum dot and corresponded to a structure having TiO2 and AgInGaS / GaS quantum dots connected by ligand chemical bonds.

[0332] 10) Comparison of quantum dot compositions 5

[0333] A quantum dot composition was prepared by the same method as quantum dot composition 1, except that the light irradiation step was omitted. That is, comparative quantum dot composition 5 corresponds to a structure having TiO2 and InP / ZnSeS and AgInGaS / GaS quantum dots not connected by ligand chemical bonds, as compared to quantum dot composition 1.

[0334] 11) Comparison of quantum dot compositions 6

[0335] A quantum dot composition was prepared by the same method as quantum dot composition 2, except that the light irradiation step was omitted. That is, comparative quantum dot composition 6 corresponds to a structure having TiO2 and InP / ZnSeS and AgInGaS / GaS quantum dots not linked by ligand chemical bonds, as compared to quantum dot composition 2.

[0336] 12) Comparison of quantum dot compositions 7

[0337] A quantum dot composition was prepared by the same method as quantum dot composition 3, except that the light irradiation step was omitted. That is, comparative quantum dot composition 7 corresponds to a structure having TiO2 and InP / ZnSeS and AgInGaS / GaS quantum dots not linked by ligand chemical bonds, as compared to quantum dot composition 3.

[0338] 13) Comparison of quantum dot compositions 8

[0339] A quantum dot composition was prepared by the same method as quantum dot composition 4, except that the light irradiation step was omitted. That is, comparative quantum dot composition 8 corresponds to a structure having TiO2 and InP / ZnSeS and AgInGaS / GaS quantum dots not linked by ligand chemical bonds, as compared to quantum dot composition 4.

[0340] 14) Comparison of quantum dot compositions 9

[0341] A quantum dot composition was prepared by the same method as quantum dot composition 5, except that the light irradiation step was omitted. That is, comparative quantum dot composition 9 corresponds to a structure having TiO2 and InP / ZnSeS and AgInGaS / GaS quantum dots not linked by ligand chemical bonds, as compared to quantum dot composition 5.

[0342] 2. Fabrication and evaluation of light-converting patterns

[0343] The light conversion patterns of Examples 1 to 5 and Comparative Examples 1 to 9 were prepared using the quantum dot compositions prepared in Quantum Dot Compositions 1 to 5 and Comparative Quantum Dot Compositions 1 to 9. The prepared quantum dot compositions were ejected onto a glass substrate by inkjet to form a film, which was then exposed and cured to form a light conversion pattern with a thickness of 10 μm.

[0344] Table 1 shows the external quantum efficiency (EQE) and absorptivity of the examples and comparative examples. The external quantum efficiency and absorptivity were measured using a quantum efficiency meter (QE2100, Otsuka Corporation). Table 1 shows the external quantum efficiency measured after irradiating the light conversion pattern with 450nm excitation light. The external quantum efficiency can be calculated according to the following formula 1. The absorptivity refers to the blue light absorptivity, which represents the amount of residual light that does not return to the light source and remains in the light conversion pattern compared to the amount of light irradiated on the light conversion pattern.

[0345] [Formula 1]

[0346] External quantum efficiency = N1 / N2×100

[0347] In Formula 1, N1 refers to the number of photons emitted from the quantum dot complex, and N2 refers to the number of photons of excitation light provided to the quantum dot complex.

[0348]

Table 1

[0349]

[0350] Referring to the results in Table 1, when comparing Examples 1 to 5 with Comparative Examples 1 and 2, it can be confirmed that the external quantum efficiencies of Examples 1 to 5, which include two different quantum dots of InP / ZnSeS and AgInGaS / GaS, are similar to those of Comparative Examples 1 and 2, which include single InP / ZnSeS quantum dots, but the absorptivity of Examples 1 to 5 is higher. Furthermore, when comparing Examples 1 to 5 with Comparative Examples 3 and 4, it can be confirmed that the absorptivity of Examples 1 to 5, which include two different quantum dots of InP / ZnSeS and AgInGaS / GaS, is similar to that of Comparative Examples 3 and 4, which include single AgInGaS / GaS quantum dots, but the external quantum efficiencies of Examples 1 to 5 are higher.

[0351] Refer to it together Figure 7 As shown in Table 1, a light conversion pattern comprising two different quantum dots, InP / ZnSeS and AgInGaS / GaS, exhibits less overlap between the absorption and emission wavelength spectra, resulting in improved external quantum efficiency, compared to a light conversion pattern comprising a single quantum dot of each of InP / ZnSeS and AgInGaS / GaS. Increased overlap between the absorption and emission wavelength spectra increases reexcitation and reabsorption of the quantum dots, leading to a decrease in quantum dot luminescence efficiency. However, when forming a light conversion pattern using two different quantum dots, the overlap between the absorption and emission wavelength spectra can be minimized, thereby preventing a decrease in the efficiency of reexcitation and reabsorption by the quantum dots.

[0352] On the other hand, if Example 1 and Comparative Example 5, Example 2 and Comparative Example 6, Example 3 and Comparative Example 7, Example 4 and Comparative Example 8, and Example 5 and Comparative Example 9, which contain two different quantum dots, are compared, it can be confirmed that Examples 1 to 5 exhibit high blue light absorption and high external quantum efficiency compared with Comparative Examples 5 to 9, respectively.

[0353] Furthermore, a comparison of Examples 1 to 5 confirms that, in Examples 1 and 2, where the weight ratio of the first and second sub-quantum dot complexes is between 1:1 and 2:1, both exhibit higher external quantum efficiencies of 35% or greater, and blue light absorptivity of 90% or greater, compared to the other Examples. These results demonstrate that the optical properties of the light conversion pattern can be adjusted by adjusting the weight ratio of the two different quantum dots. As shown in Table 1, a high optical efficiency improvement effect can be expected when the weight ratio of the first and second sub-quantum dot complexes is between 1:1 and 2:1.

[0354] By including two quantum dots with different core materials that emit the same color, the light-conversion pattern of the embodiment can simultaneously increase the external quantum efficiency and blue light absorption rate compared to a light-conversion pattern containing a single quantum dot. Furthermore, by including a scatterer and two quantum dots connected by ligands, the light-conversion pattern of the embodiment can improve the dispersibility of the two different quantum dots and prevent the reduction in light absorption due to particle aggregation. Furthermore, by connecting the scatterer to the two quantum dots, light that is not absorbed by the quantum dots can be scattered by the scatterer and easily absorbed by adjacent quantum dots. As a result, the light-conversion pattern of the embodiment can exhibit high luminous efficiency.

[0355] While the present invention has been described above with reference to preferred embodiments, those skilled in the art or those with ordinary knowledge in the art will appreciate that various modifications and variations may be made to the present invention without departing from the scope of the present invention and the technical field as set forth in the appended claims. Therefore, the technical scope of the present invention is not limited by the detailed description of the specification but is determined solely by the claims.

Claims

1. A quantum dot composition comprising: scatterers; a first quantum dot comprising a first core; a second quantum dot comprising a second core different from the first core; a first ligand, bound to the surface of the first quantum dot; a second ligand, bound to the surface of the second quantum dot; as well as a scatterer ligand, bound to the surface of the scatterer, The first ligand and the second ligand are chemically bonded to the scatterer ligand respectively.

2. The quantum dot composition according to claim 1, wherein Each of the first quantum dot and the second quantum dot absorbs the first light and emits the second light having a longer wavelength than the first light.

3. The quantum dot composition according to claim 1, wherein The maximum emission wavelength range of each of the first quantum dot and the second quantum dot is greater than or equal to 510 nm and less than or equal to 550 nm.

4. The quantum dot composition according to claim 1, wherein The first core comprises a first semiconductor nanocrystal, the second core comprises a second semiconductor nanocrystal, Each of the first semiconductor nanocrystal and the second semiconductor nanocrystal is selected from Group II-VI compounds, Group III-VI compounds, Group I-III-VI compounds, Group III-V compounds, Group III-II-V compounds, Group IV-VI compounds, Group IV elements, Group IV compounds, and combinations thereof.

5. The quantum dot composition according to claim 1, wherein The first core includes InP, and the second core includes AgInGaS.

6. The quantum dot composition according to claim 1, wherein The first ligand includes: a first head portion, which is bound to the surface of the first quantum dot; and a first tail portion, which is separated from the surface of the first quantum dot and chemically bonded to the scatterer ligand. The second ligand includes: a second head portion, which is bound to the surface of the second quantum dot; and a second tail portion, which is separated from the surface of the second quantum dot and is bonded to the scatterer ligand.

7. The quantum dot composition according to claim 6, wherein The first ligand further includes: a first connecting portion connecting the first head portion and the first tail portion, The second ligand further includes: a second connecting portion connecting the second head portion and the second tail portion.

8. The quantum dot composition according to claim 1, wherein Based on the total weight of the quantum dot composition, the sum of the content of the first quantum dots and the content of the second quantum dots is greater than or equal to 30 weight % and less than or equal to 38 weight %.

9. The quantum dot composition according to claim 1, wherein The content of the scatterer is greater than or equal to 2 wt % and less than or equal to 8 wt % based on the total weight of the quantum dot composition.

10. The quantum dot composition according to claim 1, wherein The scatterer comprises: a first scatterer, a first scatterer ligand chemically bonded to the first ligand bound to the surface; and A second scatterer, a second scatterer ligand chemically bonded to the second ligand, is bound to the surface.

11. The quantum dot composition according to claim 10, wherein When the sum of the contents of the first quantum dots, the first ligands, the first scatterer, and the first scatterer ligands is defined as a first weight, and the sum of the contents of the second quantum dots, the second ligands, the second scatterer, and the second scatterer ligands is defined as a second weight, The ratio of the first weight to the second weight is 1:1 to 2:

1.

12. The quantum dot composition according to claim 1, wherein The first quantum dot further comprises a first shell covering the first core, The second quantum dot further comprises a second shell covering the second core, The first ligand is bound to the first shell surface, The second ligand is bound to the second shell surface.

13. A display device comprising: Display panel; as well as The light conversion layer is arranged on the display panel and includes a plurality of light control parts. At least one of the plurality of light control units comprises a quantum dot complex, The quantum dot complex comprises: scatterers; a first quantum dot comprising a first core; a second quantum dot comprising a second core different from the first core; a first ligand, bound to the surface of the first quantum dot; a second ligand, bound to the surface of the second quantum dot; as well as a scatterer ligand, bound to the surface of the scatterer, The first ligand and the second ligand are chemically bonded to the scatterer ligand respectively.

14. The display device according to claim 13, wherein: The display panel includes: a light emitting element generating a first light, The light conversion layer includes: a first light control unit configured to transmit the first light; a second light control unit that converts the first light into a second light; and The third light control unit converts the first light into third light.

15. The display device according to claim 13, wherein A light control unit including the quantum dot complex among the plurality of light control units has a blue light absorption rate of 90% or more.

16. The display device according to claim 13, wherein When excitation light having a wavelength of 450 nm is irradiated onto a light control portion including the quantum dot complex among the plurality of light control portions, the external quantum efficiency is 35% or higher.

17. A method for preparing a quantum dot composition, comprising: providing a first quantum dot having a first ligand bound to its surface and comprising a first core, and a second quantum dot having a second ligand bound to its surface and comprising a second core different from the first core; providing a scatterer having a scatterer ligand bound to the surface; The step of mixing the first quantum dots bound to the first ligand and the second quantum dots bound to the second ligand with the scatterer bound to the scatterer ligand to provide a preliminary quantum dot composition; as well as A step of applying heat or light to the prepared quantum dot composition to chemically bond the scatterer ligand to each of the first ligand and the second ligand.

18. The method for preparing a quantum dot composition according to claim 17, wherein: The scatterer ligand comprises: a first functional group chemically bonded to the first ligand and the second ligand, The first functional group comprises at least one of a thiol group, an amine group, a hydroxyl group, an azide group, and an oxetane group.

19. The method for preparing a quantum dot composition according to claim 18, wherein: The first ligand comprises: a second functional group, forming a chemical bond with the first functional group, The second ligand comprises: a third functional group, forming a chemical bond with the first functional group, The second functional group and the third functional group each independently include at least one of an alkenyl group, an alkynyl group, a carboxyl group, an acyl halide group, and a (meth)acrylate group.

20. The method for preparing a quantum dot composition according to claim 17, wherein: The steps of providing the preliminary quantum dot composition and chemically bonding the scatterer ligand to each of the first ligand and the second ligand include: The step of mixing the first quantum dots bound to the first ligand and the scatterer bound to the scatterer ligand to provide a first preliminary quantum dot composition; The step of mixing the second quantum dots bound to the second ligand and the scatterer bound to the scatterer ligand to provide a second preliminary quantum dot composition; providing heat or light to the first prepared quantum dot composition and the second prepared quantum dot composition; and A step of mixing the first preliminary quantum dot composition and the second preliminary quantum dot composition provided with heat or light.

Images