Ink composition, quantum dot composite, and color conversion panel and display device including the same

Abstract

The invention relates to an ink composition comprising a plurality of quantum dots, a liquid monomer, an initiator, and optionally an organic solvent, a method for manufacturing the same, a quantum dot composite manufactured therefrom, and a color-changing panel and a display device comprising the same. The plurality of quantum dots comprises a first quantum dot comprising a first ligand and a second quantum dot comprising a second ligand different from the first ligand, and the ink composition is configured to emit a first light.

Description

Technology Field

[0001] The present disclosure relates to an ink composition (containing quantum dots), a method for manufacturing the same, a quantum dot composite (manufactured therefrom), and a color conversion panel and a display device comprising the same. Background Technology

[0002] Quantum dots are nanoscale semiconductor nanocrystalline materials whose optical properties (e.g., luminescence) can be controlled by, for instance, changing their size and / or composition. The luminescence properties of quantum dots can be applied in various electronic devices (e.g., display devices). For device applications, quantum dots or composites containing them can take the form of films or patterns, and research is currently underway to achieve this. The problem to be solved

[0003] One embodiment relates to an ink composition containing quantum dots.

[0004] One embodiment relates to a method for manufacturing the above-mentioned ink composition.

[0005] One embodiment relates to a quantum dot complex formed from the above-mentioned ink composition.

[0006] One embodiment relates to a color conversion panel or display panel comprising the above-mentioned quantum dot complex.

[0007] One embodiment relates to an electronic device (e.g., a display device) including the color conversion panel described above. means of solving the problem

[0008] In one embodiment, the ink composition comprises a plurality of quantum dots, a liquid monomer, an initiator, and optionally an organic solvent, wherein the plurality of quantum dots comprises a first quantum dot comprising a first ligand and a second quantum dot comprising a second ligand different from the first ligand, and the ink composition is configured to emit a first light (e.g., by photoexcitation).

[0009] The first light mentioned above may be green light, red light, or blue light.

[0010] The maximum emission peak of the first light above may have a full width at half maximum of 45 nm or less.

[0011] The first ligand may be bound to the first quantum dot (or its surface). The first ligand may be configured to disperse the first quantum dot within the organic solvent. The second ligand may be bound to the second quantum dot (or its surface). The second ligand may be configured to disperse the second quantum dot within the liquid monomer.

[0012] The first ligand or the second ligand may comprise RCOOH, RNH2, R2NH, R3N, RSH, R3PO, R3P, ROH, RCOOR', RPO(OH)2, RHPOOH, R2POOH, polymer organic ligands, or a combination thereof, wherein R and R' are each independently a substituted or unsubstituted C1 to C100 (e.g., C3 to C50 or C5 to C24) aliphatic hydrocarbon group, a substituted or unsubstituted C6 to C50 (e.g., C6 to C24) aromatic hydrocarbon group, or a combination thereof, and optionally, one or more methylenes within the aliphatic hydrocarbon group are sulfonyl (-SO2-), carbonyl (CO), ether (-O-), sulfide (-S-), sulfoxide (-SO-), ester (-C(=O)O-), It can be replaced with an amide (-C(=O)NR-) (where R is hydrogen or a C1 to C10 alkyl group), or a combination thereof.

[0013] The first ligand above may include a monocarboxylic acid compound having a C10 to C40 hydrocarbyl group (e.g., alkyl group, alkenyl group, or alkynyl group).

[0014] The second ligand may include an organic compound having 1 to 100 carbon atoms having a functional group selected from an amine group, a thiol group, a carboxylic acid group, a phosphine group, or a combination thereof.

[0015] The above organic compound may include a residue connected to the above functional group and represented by the following formula:

[0016]

[0017] In the above formula, L is a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C2 to C30 alkenylene group, a substituted or unsubstituted C3 to C30 cycloalkylene group, a substituted or unsubstituted C3 to C30 heterocycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a substituted or unsubstituted C3 to C30 heteroarylene group, sulfonyl (-SO2-), carbonyl (CO), ether (-O-), sulfide (-S-), sulfoxide (-SO-), ester (-C(=O)O-), amide (-C(=O)NR-) (where R is hydrogen or a C1 to C10 alkyl group), or a combination thereof, and

[0018] A is hydrogen, -COOH, -NR3 (where R is hydrogen or a C1 to C10 alkyl group), or a combination thereof, and

[0019] * is the part connected to the above functional group.

[0020] The above organic compound may be a polyfunctional organic compound having two or more of the aforementioned functional groups.

[0021] The above liquid monomer contains carbon-carbon double bonds, (e.g., has a vapor pressure of 10 at room temperature (e.g., 20°C or 25°C) -4 It may include compounds with a value of mmHg or less.

[0022] The above liquid monomer contains carbon-carbon double bonds and has a vapor pressure of 10 -5It may include compounds with a value of mmHg or less.

[0023] The above liquid monomer may include a monoacrylate compound, a diacrylate compound, a triacrylate compound, a tetraacrylate compound, a pentaacrylate compound, or a hexaacrylate compound, or a combination thereof.

[0024] The above liquid monomer may include hexamethylene di(meth)acrylate, tetraethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, or a combination thereof.

[0025] The above organic solvent may have a vapor pressure of 5 mmHg or less.

[0026] The above organic solvent may have a vapor pressure of 4 mmHg or less, 3 mmHg or less, 2.5 mmHg or less, or 1 mmHg or less.

[0027] The above organic solvent may include a C3 to C40 substituted or unsubstituted aliphatic hydrocarbon solvent, a C6 to 40 substituted or unsubstituted aromatic hydrocarbon solvent, a C3 to C40 substituted or unsubstituted alicyclic hydrocarbon solvent, an alkylene glycol alkyl ether acetate solvent, an alkylacetamide solvent, or a combination thereof.

[0028] The above organic solvent may include propylene glycol monomethyl ether acetate (PGMEA), dimethylacetamide (DMA), cyclohexyl acetate (CHA), or a combination thereof.

[0029] The above ink composition may further include a dispersant.

[0030] In one embodiment, the dispersant may have an acid value of 5 mg KOH / g or less. In one embodiment, the dispersant may have an acid value of 5 mg KOH / g or more, 10 mg KOH / g or more, 20 mg KOH / g or more, or 35 mg KOH / g or more.

[0031] In one embodiment, the dispersant may have an amine value of 5 mg KOH / g or less. In one embodiment, the dispersant may have an amine value of 5 mg KOH / g or more, 10 mg KOH / g or more, 20 mg KOH / g or more, or 35 mg KOH / g or more.

[0032] When the above-mentioned dispersant has both an acid value and an amine value (in other words, when it is amphoteric), the difference between the acid value and the amine value in the above-mentioned dispersant may be less than 5. When the above-mentioned dispersant is amphoteric, the acid value and the amine value of the above-mentioned dispersant may both be 35 mg KOH / g or higher.

[0033] The above ink composition may further include a plurality of metal oxide microparticles.

[0034] The above metal oxide microparticles may include titanium oxide, silicon oxide, barium oxide, zinc oxide, hafnium oxide, zirconium oxide, aluminum oxide, gallium oxide, indium oxide, germanium oxide, tin oxide, antimony oxide, scandium oxide, yttrium oxide, lanthanum oxide, ruthenium oxide, cerium oxide, tantalum oxide, niobium oxide, or a combination thereof.

[0035] The average size of the metal oxide microparticles may be 150 nm or more and / or 500 nm or less.

[0036] The ink composition may have a viscosity of 40 cPs or less, 30 cPs or less, 25 cPs or less, 20 cPs or less, 15 cPs or less, or 10 cPs or less at room temperature or ambient temperature (e.g., 25°C or 20°C). The ink composition may have a surface tension of 15 mN / m or more at 23°C. The ink composition may have a vapor pressure of 5 mmHg or less, e.g., 1 mmHg or less, 10 -1 mmHg or less, 10 -2 mmHg or less, 10 -3 mmHg or less, or 10 -4 mmHg or less, or 10 -5 It may be less than mmHg.

[0037] The above ink composition may simultaneously exhibit acid value and amine value. The above ink composition may have both acid value and amine value of 35 mg KOH / g or higher, for example, 40 mg KOH / g or higher, or acid value and amine value or the difference thereof may be 5 mg KOH / g or lower (e.g., 3 mg KOH / g or lower).

[0038] The above ink composition may have a residual film rate of 90% or more after 30 minutes in film form.

[0039] The above ink composition is configured to exhibit a relative EQE of 104% or less relative to the initial external quantum efficiency (EQE) during 100 hours of irradiation with excitation light of a wavelength of 450 nm at a temperature of 60°C in the solid state after polymerization.

[0040] In another embodiment, the ink composition comprises a liquid vehicle comprising an organic solvent and a liquid monomer, a plurality of quantum dots dispersed within the liquid vehicle, and optionally metal oxide microparticles, wherein the content of the organic solvent in the ink composition is 20% by weight or less based on the total weight of the composition, and the ink composition is configured to exhibit a relative EQE relative to the initial external quantum efficiency (EQE) of 104% or less during irradiation with excitation light of a wavelength of 450 nm at a temperature of 60°C in a solid state after polymerization for 100 hours.

[0041] In the above ink composition, the content of the plurality of quantum dots may be 1 wt% or more, 20 wt% or more, 30 wt% or more, 40 wt% or more, 45 wt% or more, 70 wt% or less, 60 wt% or less, or 55 wt% or less, based on the total solid content of the composition.

[0042] In the ink composition above, the weight ratio between the first quantum dot and the second quantum dot (weight of the first quantum dot: weight of the second quantum dot) may be 1:99 to 99:1.

[0043] In the above ink composition, if present, the content of the metal oxide microparticles may be 1 weight% or more, 5 weight% or more, 10 weight% or more, 20 weight% or less, and 15 weight% or less based on the total solid content of the composition.

[0044] In the above ink composition, the content of the liquid monomer may be 1 weight% or more, 5 weight% or more, 10 weight% or more, 50 weight% or less, 45 weight% or less, 40 weight% or less, 35 weight% or less, 30 weight% or less, or 25 weight% or less, based on the total solid content of the composition.

[0045] In the above ink composition, the content of the initiator may be 0.01 weight% or more and 10 weight% or less based on the total solid content of the composition.

[0046] In the above ink composition, the content of the organic solvent may be 0.01 wt% or more, or 1 wt% or more, 5 wt% or more, 10 wt% or more, 15 wt% or more, or 20 wt% or more and 50 wt% or less, 40 wt% or less, 30 wt% or less, 25 wt% or less, 15 wt% or less, 10 wt% or less, or 5 wt% or less, based on the total weight of the ink composition.

[0047] In another embodiment, the method for preparing the ink composition is,

[0048] A step of preparing a first solution comprising the first quantum dot and the organic solvent,

[0049] A step of preparing a second solution comprising the second quantum dot and the liquid monomer; and

[0050] The method includes the step of mixing the first solution and the second solution substantially without precipitation (e.g., while maintaining a colloidal dispersion state).

[0051] The first solution may further include the initiator, the dispersant, the metal oxide microparticles, or a combination thereof.

[0052] The second solution may further include the initiator, the dispersant, the metal oxide microparticles, or a combination thereof.

[0053] At least one of the first solution or the second solution may include the initiator.

[0054] The above method may further include the step of removing at least a portion of the organic solvent from the ink composition.

[0055] The above first solution and the above second solution may satisfy one of the following conditions:

[0056] At least one of the first solution and the second solution does not exhibit both acid value and amine value;

[0057] If the first solution exhibits either an acid value or an amine value, the second solution exhibits either an acid value or an amine value;

[0058] If the first solution is amphoteric, exhibiting both acid value and amine value, the second solution is also amphoteric; or

[0059] In the case where one of the first solution and the second solution is amphoteric and the other represents an acid value or an amine value, in the amphoteric solution, the difference between the acid value and the amine value may be less than 5 mg KOH / g, or both the acid value and the amine value may be 35 mg KOH / g or more.

[0060] In one embodiment, the quantum dot complex comprises a matrix and a plurality of quantum dots dispersed within the matrix, wherein the plurality of quantum dots comprises a first quantum dot comprising a first ligand and a second quantum dot comprising a second ligand different from the first ligand, and the quantum dot complex is configured to emit light of a predetermined wavelength (e.g., by photoexcitation) and to exhibit a relative EQE with respect to the initial external quantum efficiency (EQE) of 104% or less during irradiation with excitation light of a wavelength of 450 nm at a temperature of 60 degrees Celsius for 100 hours.

[0061] The light of the above predetermined wavelength may be green light or red light.

[0062] The above matrix may include a cross-linked polymer (e.g., a polymerization product of the liquid monomer).

[0063] The above matrix may not include a linear polymer having carboxylic acid groups, a cardo binder, or a combination thereof.

[0064] The above quantum dot complex can be manufactured from the aforementioned ink composition.

[0065] In one embodiment, the color conversion panel comprises a color conversion layer including a color conversion zone and a partition defining each zone of the color conversion layer according to selection, wherein the color conversion zone includes a first zone configured to emit a first light (e.g., by irradiation with excitation light), and the first zone includes the quantum dot complex.

[0066] The above color conversion zone includes a second zone configured to emit a second light different from the first light (e.g., by irradiation with excitation light), and the second zone may further include a second zone comprising the quantum dot complex.

[0067] In one embodiment, the display panel includes a light-emitting panel, a color-converting panel, and a light-transmitting layer located between the light-emitting panel and the color-converting panel.

[0068] In one embodiment, the electronic device (or display device) includes the color conversion panel or the display panel. Effects of the invention

[0069] The ink composition of one embodiment, when applied to, for example, an inkjet printing method, can exhibit improved jetting characteristics and can provide a large-area quantum dot (composite) single film or pattern. According to the manufacturing method of one embodiment, a composition having desired physical properties (e.g., viscosity, etc.) can be produced while suppressing or preventing phase separation or precipitation. When the formed quantum dot single film or pattern is applied to a device, it can exhibit operational stability without abrupt changes in luminous efficiency. Brief explanation of the drawing

[0070] FIG. 1 is a perspective view showing an example of a display panel according to one embodiment, and FIG. 2 is a cross-sectional view of the display panel of FIG. 1, and FIG. 3 is a plan view showing an example of a pixel arrangement of a display panel of FIG. 1, and FIG. 4 is a cross-sectional view of the display panel of FIG. 3 taken along the line IV-IV, and FIG. 5 is a cross-sectional view showing a non-limiting example of a light-emitting element, and FIG. 6a shows an inkjet ejection photograph of the ink composition of Comparative Example 1, and FIG. 6b shows an inkjet ejection photograph of the ink composition of Example 1, and FIG. 7 is a graph showing the change in residual film rate over time of films prepared from the quantum dot solution of Reference Example 1 (first solution), the ink composition of Comparative Example 1, and the ink composition of Example 1. Figure 8 is a graph showing the change in external quantum efficiency over time of a quantum dot composite prepared from the ink composition of Comparative Example 1 and a quantum dot composite prepared from the ink composition of Example 1. Specific details for implementing the invention

[0071] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0072] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0073] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0074] Furthermore, when it is said that a part, such as a layer, membrane, region, or plate, is "on" or "on" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when it is said that a part is "directly above" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" in the direction opposite to gravity.

[0075] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0076] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0077] Unless otherwise defined below, "substitution" means that hydrogen in a compound, group, or moiety is a C1 to C30 alkyl group, C2 to C30 alkenyl group, C2 to C30 alkynyl group, C2 to C30 epoxy group, C2 to C30 alkenyl group, C2 to C30 alkyl ester group, C3 to C30 alkenyl ester group (e.g., acrylate group, methacrylate group), C6 to C30 aryl group, C7 to C30 alkylaryl group, C1 to C30 alkoxy group, C1 to C30 heteroalkyl group, C3 to C30 heteroalkylaryl group, C3 to C30 cycloalkyl group, C3 to C15 cycloalkenyl group, C6 to C30 cycloalkynyl group, C2 to C30 Heterocycloalkyl group, halogen (-F, -Cl, -Br, or -I), hydroxyl group (-OH), nitro group (-NO2), cyano group (-CN), amino group (-NRR', where R and R' are independently hydrogen or C1 to C6 alkyl groups), azido group (-N3), amido group (-C(=NH)NH2), hydrazino group (-NHNH2), hydrazono group (=N(NH2), aldehyde group (-C(=O)H), carbamoyl group (-C(O)NH2), thiol group (-SH), ester group (-C(=O)OR, where R is a C1 to C6 alkyl group or a C6 to C12 aryl group), carboxyl group (-COOH) or its salt (-C(=O)OM, where M is an organic or inorganic cation), sulfonic acid group (-SO3H) or its It means being replaced by a salt (-SO3M, where M is an organic or inorganic cation), a phosphate group (-PO3H2) or its salt (-PO3MH or -PO3M2, where M is an organic or inorganic cation), and a substituent selected from combinations thereof.

[0078] Also, unless otherwise defined below, "hetero" means containing 1 to 3 heteroatoms selected from N, O, S, Si, and P.

[0079] In this specification, "alkylene group" is a straight-chain or branched-chain saturated aliphatic hydrocarbon group having two or more valences, optionally comprising one or more substituents. In this specification, "arylene group" means a functional group having two or more valences formed by the removal of at least two hydrogens from one or more aromatic rings, optionally comprising one or more substituents. In this specification, "alkyl group" is a monovalent straight-chain or branched-chain saturated aliphatic hydrocarbon group (e.g., optionally comprising one or more substituents). One or more methylene groups in the alkyl group or alkylene group may be replaced with sulfonyl (-SO2-), carbonyl (CO), ether (-O-), sulfide (-S-), sulfoxide (-SO-), ester (-C(=O)O-), amide (-C(=O)NR-) (where R is hydrogen or a C1 to C10 alkyl group), or a combination thereof.

[0080] In one embodiment, "aliphatic hydrocarbon group" may mean a substituted or unsubstituted straight-chain or branched-chain hydrocarbon group of C1 to C100 (e.g., C1 to C30 alkyl, C2 to C30 alkenyl, C2 to C30 alkynyl). In one embodiment, "aromatic hydrocarbon group" may mean a substituted or unsubstituted aryl group of C6 to C60 or a heteroaryl group of C2 to C60.

[0081] In this specification, the term "(meth)acrylate" refers to acrylate and / or methacrylate.

[0082] In this specification, "Group" refers to a group of the periodic table of elements.

[0083] Here, "Group II" may include Group IIA and Group IIB, and examples of Group II metals include, but are not limited to, Cd, Zn, Hg and Mg.

[0084] "Group III" may include Group IIIA and Group IIIB, and examples of Group III metals include, but are not limited to, Al, In, Ga, and Tl.

[0085] "Group IV" may include Groups IVA and IVB, and examples of Group IV metals may include, but are not limited to, Si, Ge, and Sn. In this specification, the term "metal" also includes metalloids such as Si.

[0086] "Group I" may include Group IA and Group IB, and includes, but is not limited to, Li, Na, K, Rb, and Cs.

[0087] "Group V" includes Group VA and includes, but is not limited to, nitrogen, phosphorus, arsenic, antimony, and bismuth.

[0088] "Group VI" includes Group VIA and includes, but is not limited to, sulfur, selenium, and tellurium.

[0089] In this specification, “cadmium-free” or “cadmium-free” means that the cadmium content in the structure is 100 ppm by weight (ppmw) or less. The Restriction of Hazardous Substances (RoHS) definition of compliance requires that cadmium in unprocessed homogeneous precursor materials be 0.01% by weight (100 ppm) or less. Here, the cadmium level in “cadmium-free” or “cadmium-free” quantum dots is limited by the trace metal concentration in the precursor materials. The trace metal concentration (containing cadmium) in the cadmium-free or cadmium-free quantum dots or their precursors can be measured by inductively coupled plasma mass spectrometry (ICP-MS) analysis and may be at the ppb (parts per billion) level. In one embodiment, the cadmium (or the element) content in a "cadmium-free" quantum dot may be less than about 50 ppm, between about 20 ppm and about 10 ppm, or less than about 1 ppm.

[0090] Quantum dots are nanoscale semiconductor nanocrystals that exhibit quantum confinement effects. When a quantum dot receives light from an excitation source and reaches an energy-excited state, it can emit energy (e.g., light) corresponding to its bandgap energy. The electrical and optical properties of quantum dots can be controlled by adjusting their size and / or composition. Quantum dots can be applied to various devices, such as photodetectors and light-emitting devices. For device applications, quantum dots can take the form of composite films (or patterns thereof) dispersed within a liquid vehicle (e.g., containing organic monomers or polymers). Inkjet printing is expected to provide large-area quantum dot composite films or patterns with high efficiency. However, since the physical properties of quantum dots (e.g., luminescence properties) are significantly affected by the external environment, providing films or patterns capable of exhibiting desired properties (e.g., luminescence efficiency, reliability, etc.) through solution processes (e.g., inkjet printing) can be a technically challenging task.

[0091] An ink composition according to one embodiment can provide a quantum dot composite monolayer (or a pattern thereof) capable of exhibiting enhanced physical properties (e.g., through a solution process).

[0092] In one embodiment, the ink composition comprises a plurality of quantum dots, a liquid monomer, an initiator, and optionally (a limited amount) of an organic solvent. The plurality of quantum dots comprises a first quantum dot comprising a first ligand and a second quantum dot comprising a second ligand different from the first ligand.

[0093] In one embodiment, the ink composition comprises a liquid vehicle comprising an organic solvent and a liquid monomer, a plurality of quantum dots dispersed within the liquid vehicle, and optionally metal oxide microparticles, and the ink composition may comprise an organic solvent of 20% by weight or less, e.g., 15% by weight or less, based on the total weight of the composition. The ink composition may exhibit improved stability (e.g., improved reliability when applied to a device).

[0094] The ink composition is configured to emit a first light (or light of a predetermined wavelength, hereinafter referred to as the first light) upon photoexcitation. The first light may be green light, red light, or blue light (depending on the plurality of quantum dots). The maximum emission peak wavelength of the green light may be in the range of 500 nm to 580 nm. The maximum emission peak wavelength of the red light may be in the range of 650 nm to 670 nm. The maximum emission peak wavelength of the blue light may be in the range of 440 nm to 490 nm. The first light has a single maximum emission peak (e.g., is a single-color light), and the full width at half maximum of the maximum emission peak may be 45 nm or less, 40 nm or less, 35 nm, 30 nm or less, or 25 nm or less.

[0095] The plurality of quantum dots (e.g., a first quantum dot and / or a second quantum dot, hereinafter referred to as quantum dots) may include a Group II-VI compound, a Group III-V compound, a Group IV-VI compound, a Group IV element or compound, a Group I-III-VI compound, a Group II-III-VI compound, a Group I-II-IV-VI compound, or a combination thereof. The plurality of quantum dots may not include cadmium. The plurality of quantum dots may not include lead, mercury, or a combination thereof.

[0096] The above-mentioned Group II-VI compounds are diatomic compounds selected from the group consisting of CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and mixtures thereof; ternary compounds selected from the group consisting of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, and mixtures thereof; and may be selected from the group consisting of four-element compounds selected from the group consisting of HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and mixtures thereof. The group II-VI compounds may further include a group III metal.

[0097] The above III-V group compounds may be selected from the group consisting of: diatomic compounds selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; ternary compounds selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, and mixtures thereof; and quaternary compounds selected from the group consisting of GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, InZnP, and mixtures thereof. The above III-V compounds may further include a Group II metal (e.g., InZnP).

[0098] The above IV-VI group compounds may be selected from the group consisting of diatomic compounds selected from 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.

[0099] Examples of the above Group I-III-VI compounds include, but are not limited to, CuInSe2, CuInS2, CuInGaSe, and CuInGaS. Examples of the above Group I-II-IV-VI compounds include, but are not limited to, CuZnSnSe and CuZnSnS.

[0100] The above Group IV element or compound may be selected from the group consisting of a monatomic element selected from the group consisting of Si, Ge, and mixtures thereof; and a diatomic compound selected from the group consisting of SiC, SiGe, and mixtures thereof.

[0101] The above-mentioned binary compound, ternary compound, or quaternary compound may exist within the particle at a uniform concentration, or may exist within the same particle with a concentration distribution divided into partially different states. The above-mentioned quantum dot may have a core / shell structure in which a first semiconductor nanocrystal surrounds another second semiconductor nanocrystal. The interface between the core and the shell may have a concentration gradient in which the concentration of the element present in the shell decreases toward the center. Additionally, the above-mentioned semiconductor nanocrystal may have a structure comprising a single semiconductor nanocrystal core and a multilayer shell surrounding it. In this case, the multilayer shell structure may have two or more layers, and each layer may have a single composition, an alloy, or a concentration gradient.

[0102] In the above quantum dots, the shell material and the core material may have different bandgap energies. For example, the bandgap energy of the shell material may be greater than that of the core material. In another embodiment, the bandgap energy of the shell material may be smaller than that of the core material. The above quantum dots may have a multilayer shell. In a multilayer shell, the energy bandgap of the outer layer may be greater than the energy bandgap of the inner layer (i.e., the layer closest to the core). In a multilayer shell, the energy bandgap of the outer layer may be smaller than the energy bandgap of the inner layer. The quantum dots may have their absorption / emission wavelengths controlled by adjusting their composition and size. The quantum dots may emit green light, red light, or blue light. The maximum emission peak wavelength of the quantum dots may have a wavelength range of ultraviolet to infrared wavelengths or longer.

[0103] For example, the maximum emission peak wavelength of the quantum dot may be 300 nm or more, e.g., 500 nm or more, 510 nm or more, 520 nm or more, 530 nm or more, 540 nm or more, 550 nm or more, 560 nm or more, 570 nm or more, 580 nm or more, 590 nm or more, 600 nm or more, or 610 nm or more. The maximum emission peak wavelength of the quantum dot may be in the range of 800 nm or less, e.g., 650 nm or less, 640 nm or less, 630 nm or less, 620 nm or less, 610 nm or less, 600 nm or less, 590 nm or less, 580 nm or less, 570 nm or less, 560 nm or less, 550 nm or less, or 540 nm or less. The maximum emission peak wavelength of the above quantum dot may be in the range of 500 nm to 650 nm.

[0104] The maximum emission peak wavelength of the quantum dot emitting green light (or the center wavelength of the green light if the first light is green light) may be in the range of 500 nm to 580 nm, 510 nm to 560 nm, or 520 nm to 540 nm. The maximum emission peak wavelength of the quantum dot emitting red light (or the wavelength of the red light if the first light is red light) may be in the range of 600 nm to 670 nm, 610 nm to 650 nm, or 620 nm to 640 nm. The maximum emission peak wavelength of the quantum dot emitting blue light (or the center wavelength of the blue light if the first light is blue light) may be 440 nm or more, 450 nm or more and 480 nm or less, or 470 nm or less.

[0105] Quantum dots can have a quantum efficiency of about 10% or more, for example, about 30% or more, about 50% or more, about 60% or more, about 70% or more, about 90% or more, or even 100%. Quantum dots can have a full width at half maximum of an emission wavelength spectrum of about 50 nm or less, for example, about 45 nm or less, about 40 nm or less, or about 30 nm or less.

[0106] The above quantum dot(s) may have an (average) size of about 1 nm or more and about 100 nm or less. The (average) size of the above quantum dot(s) may be about 1 nm to about 20 nm, e.g., 2 nm or more, 3 nm or more, or 4 nm or more and 50 nm or less, 40 nm or less, 30 nm or less, 20 nm or less, 15 nm or less, e.g., 10 nm or less. The shape of the quantum dot is not particularly limited. For example, the shape of the above quantum dot may include, but is not limited to, a sphere, a polyhedron, a pyramid, a multipod, a square, a rectangular prism, a nanotube, a nanorod, a nanowire, a nanosheet, or a combination thereof. The quantum dots may be commercially available or suitably synthesized. The plurality of quantum dots may not include pervskite-based quantum dots.

[0107] In one embodiment, quantum dots can be synthesized by a wet synthesis method and may include an organic ligand (hereinafter also referred to as a native ligand) (e.g., bonded to its surface). The organic ligand coordinates the surface of the prepared nanocrystal (quantum dot) and can enable the quantum dots to be dispersed in a medium (e.g., a solution or monomer). The organic ligand can affect the physical properties of the quantum dots (e.g., luminescence and electrical properties).

[0108] In the ink composition of one embodiment, the organic ligands having a plurality of quantum dots may have a functional group for binding to the quantum dots and a residue for dispersion in a medium (e.g., liquid vehicle, organic solvent, or liquid monomer).

[0109] In the plurality of quantum dots above, a first ligand contained in the first quantum dot can help disperse the quantum dots in a predetermined organic solvent. The first ligand may be a native ligand. However, as confirmed by the inventors, the first ligand is not easy to provide the desired degree or level of dispersibility with respect to the desired liquid monomer. The liquid monomer may be necessary for the formation of a solid-state quantum dot film in the ink composition (e.g., through polymerization). Therefore, if the liquid vehicle contains a significant amount of the liquid monomer, the first quantum dot may not be able to exhibit the degree of dispersibility required for film formation.

[0110] In the ink composition of one embodiment, the plurality of quantum dots further include a second quantum dot to which a second ligand is bound. The second ligand may be configured to disperse the second quantum dot in the liquid monomer. The second quantum dots having the second ligand may be dispersed in the liquid monomer to form a liquid monomer-quantum dot composition that exhibits, for example, colloidal dispersibility.

[0111] However, as confirmed by the inventors, when a quantum dot film obtained by polymerization from the liquid monomer-quantum dot composition is exposed to light of short wavelength (e.g., 440 nm to 480 nm, 450 nm to 460 nm) and to a temperature raised (e.g., 50°C or higher, or 60°C or higher) for an extended period (e.g., 10 hours or more, 50 hours or more, 100 hours or more, or 150 hours or more), it may exhibit a luminescence efficiency that is significantly changed (e.g., significantly increased) compared to the initial luminescence efficiency of the quantum dots (hereinafter this phenomenon is referred to as overshoot). Although not bound by any specific theory, it is thought that this change in efficiency is due to the quantum dots recovering their original efficiency through the rearrangement of organic ligands within the matrix. This change in efficiency can have a negative impact on the operational reliability of the device (e.g., the final device).

[0112] Surprisingly, the inventors have confirmed that an ink composition obtained by mixing the aforementioned liquid monomer quantum dot composition with an organic solution containing first quantum dots having a first ligand can solve the aforementioned overshoot problem while exhibiting desired dispersibility. Furthermore, as confirmed by the inventors, the addition of an organic solution containing first quantum dots can enable the final quantum dot ink composition to have an increased content of inorganic material while exhibiting a desired viscosity (e.g., a reduced level).

[0113] In one embodiment, viscosity can be measured by any known method. The viscosity can be measured using a commercially available rheometer (or viscometer) (e.g., the Hakke series manufactured by Thermo Fisher Scientific). For example, the viscosity can be measured using a rotational rheometer, an elongation rheometer, a falling ball viscometer, a rotational viscometer, etc.

[0114] The first ligand or the second ligand may include RCOOH, RNH2, R2NH, R3N, RSH, R3PO, R3P, ROH, RCOOR', RPO(OH)2, RHPOOH, R2POOH, polymer organic ligands, or a combination thereof. Here, R and R' may each independently include a substituted or unsubstituted C1 to C100 (e.g., C3 to C50 or C5 to C24) aliphatic hydrocarbon group, a substituted or unsubstituted C6 to C50 (e.g., C6 to C24) aromatic hydrocarbon group, or a combination thereof. Optionally, one or more methylenes in the aliphatic hydrocarbon group may be replaced with sulfonyl (-SO2-), carbonyl (CO), ether (-O-), sulfide (-S-), sulfoxide (-SO-), ester (-C(=O)O-), amide (-C(=O)NR-) (where R is hydrogen or a C1 to C10 alkyl group), or a combination thereof. The polymer organic ligand may have a polyurethane residue.

[0115] The above first ligand (or second ligand) is a C1 to C100 substituted or unsubstituted alkylamine (ethylamine, propylamine, butylamine, pentylamine, hexylamine, octylamine, dodecylamine, hexadecylamine, octadecylamine, dimethylamine, diethylamine, dipropylamine, trioctylamine); a C2 to C40 substituted or unsubstituted carboxylic acid compound (e.g., methanoic acid, ethanoic acid, propanoic acid, butanoic acid, pentasanic acid, hexanoic acid, heptanoic acid, octanoic acid, dodecanoic acid, hexadecanoic acid, octadecanic acid, oleic acid, benzoic acid); Examples include compounds of methylphosphine, ethylphosphine, propylphosphine, butylphosphine, pentylphosphine, diphenylphosphine, triphenylphosphine, etc., or mono-, di-, or trialkyl or aryl phosphines or their oxide compounds (or phosphine oxide compounds); their oxide compounds; C5 to C20 phosphonic acids; C5 to C20 phosphinic acids, etc. The first organic ligand or the second ligand may be used alone or as a mixture of two or more.

[0116] The first organic ligand and the second ligand may not exhibit acid value and amine value. The first organic ligand and the second organic ligand may each independently exhibit an acid value or an amine value (as described below) depending on the choice. If the first organic ligand exhibits both acid value and amine value (e.g., amphoteric), the second organic ligand may also exhibit amphotericity. Acid value, amine value, and amphotericity are described in more detail below with reference to the dispersant and ink manufacturing method, and the contents thereof may also apply to the first organic ligand and the second organic ligand.

[0117] In one embodiment, the first ligand may comprise a monocarboxylic acid compound having a C10 to C40 hydrocarbyl group (e.g., alkyl group, alkenyl group, or alkynyl group), a monoamine compound having a C10 to C40 hydrocarbyl group (e.g., alkyl group, alkenyl group, or alkynyl group), or a combination thereof. The first ligand may comprise oleic acid, oleylamine, or a combination thereof.

[0118] In one embodiment, the second ligand may comprise a (polyfunctional) organic compound having 1 to 100 carbon atoms (e.g., C5 to C60, C7 to C20) having a functional group selected from an amine group, a thiol group, a carboxylic acid group, a phosphine group, or a combination thereof.

[0119] The above organic compound may include a residue connected to the above functional group and represented by the following formula:

[0120]

[0121] In the above formula, L is a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C2 to C30 alkenylene group, a substituted or unsubstituted C3 to C30 cycloalkylene group, a substituted or unsubstituted C3 to C30 heterocycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a substituted or unsubstituted C3 to C30 heteroarylene group, sulfonyl (-SO2-), carbonyl (CO), ether (-O-), sulfide (-S-), sulfoxide (-SO-), ester (-C(=O)O-), amide (-C(=O)NR-) (where R is hydrogen or a C1 to C10 alkyl group), or a combination thereof, and

[0122] A is hydrogen, -COOH, -NR3 (where R is hydrogen or a C1 to C10 alkyl group), or a combination thereof, and

[0123] * is a site connected to the above functional group (e.g., amine group, thiol group, carboxylic acid group, phosphine group, or a combination thereof).

[0124] If desired, the second organic ligand may be bound to the second quantum dot (e.g., through an organic ligand exchange process). The organic ligand exchange process may be carried out by reacting the organic ligand for exchange and the quantum dot in an organic solvent, for example, under an elevated temperature. The organic solvent for the ligand exchange reaction is not particularly limited, and any suitable solvent used for quantum dot colloid synthesis may be selected. The organic solvent may be a primary alkylamine of C6 to C22 such as hexadecylamine; a secondary alkylamine of C6 to C22 such as dioctylamine; a tertiary alkylamine of C6 to C40 such as trioctylamine; a nitrogen-containing heterocyclic compound such as pyridine; or an aliphatic hydrocarbon of C6 to C40 such as hexadecane, octadecane, octadecene, squalane, etc. (e.g., alkanes, alkenes, alkynes, etc.). It may be selected from the group consisting of C6 to C30 aromatic hydrocarbons such as phenyldodecane, phenyltetradecane, and phenylhexadecane; phosphines substituted with C6 to C22 alkyl groups such as trioctylphosphine; phosphines substituted with C6 to C22 alkyl groups such as trioctylphosphine oxide; C12 to C22 aromatic ethers such as phenyl ether and benzyl ether; and combinations thereof. The temperature of the ligand exchange reaction may be appropriately selected and may be 40°C or higher, 50°C or higher, or 60°C or higher and 150°C or lower, 140°C or lower, or 100°C or lower, but is not limited thereto.

[0125] In the above ink composition, the content of the plurality of quantum dots may be 1 wt% or more, 5 wt% or more, 10 wt% or more, 15 wt% or more, 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, 40 wt% or more, 45 wt% or more, or 48 wt% or more, based on the total solid content of the composition. In the above ink composition, the content of the plurality of quantum dots may be 60 wt% or less, 55 wt% or less, 50 wt% or less, 45 wt% or less, 40 wt% or less, or 35 wt% or less, based on the total solid content of the composition. The ink composition of one embodiment may exhibit an increased inorganic content due to improved dispersion characteristics.

[0126] The content ratio between the second quantum dots and the first quantum dots in the ink composition can be appropriately selected. In one embodiment, the weight ratio between the first quantum dots and the second quantum dots may be in the range of 1:99 to 99:1, 5:95 to 95:5, 10:90 to 90:10, 15:85 to 85:15, 20:80 to 80:20, 25:75 to 75:25, 30:70 to 70:30, 35:65 to 65:35, 40:60 to 60:40, 45:55 to 55:45, or a combination thereof.

[0127] In the ink composition of one embodiment, the liquid monomer contains carbon-carbon double bonds and has a vapor pressure of 10 -4 mmHg or less, e.g., 10 -5 It may include compounds with a value of mmHg or less. In this specification, vapor pressure, viscosity, surface tension, etc., may be values ​​measured at room temperature or ambient temperature, e.g., 20°C to 25°C (e.g., 20°C, 23°C, 25°C).

[0128] The above liquid monomer may include a C3 to C100 monoacrylate compound, a C6 to C150 diacrylate compound, a C9 to C200 triacrylate compound, a C12 to 250 tetraacrylate compound, a pentaacrylate compound, or a C18 to 300 hexaacrylate compound, or a combination thereof. The above liquid monomer may form a polymer (e.g., electrically insulating) by polymerization, and the quantum dot complex described below may include the polymer as a matrix, for example.

[0129] The above liquid monomer may include an acrylate compound. The above acrylate compounds are alkyl (meth)acrylates, ethylene glycol di(meth)acrylates, triethylene glycol di(meth)acrylates, diethylene glycol di(meth)acrylates, 1,4-butanediol di(meth)acrylates, 1,6-hexanediol di(meth)acrylates, neopentyl glycol di(meth)acrylates, pentaerythritol di(meth)acrylates, pentaerythritol tri(meth)acrylates, pentaerythritol tetra(meth)acrylates, dipentaerythritol di(meth)acrylates, dipentaerythritol tri(meth)acrylates, dipentaerythritol penta(meth)acrylates, pentaerythritol hexa(meth)acrylates, bisphenol A di(meth)acrylates, It may include bisphenol A epoxyacrylate, trimethylolpropane tri(meth)acrylate, ethylene glycol monomethyl ether (meth)acrylate, novolac epoxy (meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, tris(meth)acryloyloxyethyl phosphate, or a combination thereof. In one embodiment, the monomer may include, but is not limited to, a di(meth)acrylate compound, a tri(meth)acrylate compound, a tetra(meth)acrylate compound, a penta(meth)acrylate compound, a hexa(meth)acrylate compound, or a combination thereof.

[0130] In one embodiment, the liquid monomer may include hexamethylene di(meth)acrylate, tetraethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, or a combination thereof.

[0131] In the above ink composition, the content of the liquid monomer may be 1 wt% or more, 5 wt% or more, 10 wt% or more, 15 wt% or more, 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, or 40 wt% or more, based on the total solid content of the composition. In the above ink composition, the content of the liquid monomer may be 60 wt% or less, 55 wt% or less, 50 wt% or less, 45 wt% or less, 40 wt% or less, 35 wt% or less, 30 wt% or less, 25 wt% or less, 20 wt% or less, or 15 wt% or less, based on the total solid content of the composition.

[0132] The ink composition may further include an organic solvent. The organic solvent may be a solvent capable of dispersing the first quantum dot. The organic solvent may include a C3 to C40 substituted or unsubstituted aliphatic hydrocarbon solvent, a C6 to 40 substituted or unsubstituted aromatic hydrocarbon solvent, a C3 to C40 substituted or unsubstituted alicyclic hydrocarbon solvent, an alkylene glycol alkyl ether acetate solvent, an alkylacetamide solvent, or a combination thereof. The organic solvent may have a vapor pressure of 5 mmHg or less, 4 mmHg or less, 3.5 mmHg or less, 3 mmHg or less, 2.5 mmHg or less, or 1 mmHg or less. The organic solvent may include dipropylene glycol monomethyl ether acetate (DPMA), polyglycidyl methacrylate (PGMA), diethylene glycol monoethyl ether acetate (EDGAC), propylene glycol methyl ether acetate (PGMEA), dialkylacetamide (e.g., dimethylacetamide DMA), cyclohexyl acetate (CHA), or a combination thereof. The organic solvent may include or not include chloroform, chlorobenzene (or halogenated aromatics), cyclohexane, hexane, heptane, octane, hexadecane, undecane, decane, dodecane, xylene, toluene, benzene, octadecane, tetradecane, butyl ether, ethanol, or a combination thereof.

[0133] In the above ink composition, the content of the organic solvent may be 0.01 wt% or more, 0.05 wt% or more, 0.1 wt% or more, 0.5 wt% or more, 1 wt% or more, 2 wt% or more, 3 wt% or more, 4 wt% or more, 5 wt% or more, 6 wt% or more, 7 wt% or more, 8 wt% or more, 9 wt% or more, 10 wt% or more, 12 wt% or more, 15 wt% or more, based on the total weight of the ink composition.

[0134] In the above ink composition, the content of the organic solvent may be 50 wt% or less, 40 wt% or less, 30 wt% or less, 25 wt% or less, 20 wt% or less, 19 wt% or less, 18 wt% or less, 17 wt% or less, 16 wt% or less, 15 wt% or less, 14 wt% or less, 13 wt% or less, 12 wt% or less, 10 wt% or less, 9 wt% or less, 8 wt% or less, 7 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, 3 wt% or less, 2 wt% or less, or 1 wt% or less, based on the total weight of the ink composition.

[0135] In the ink composition of one embodiment, the initiator is a compound capable of initiating the polymerization (e.g., radical polymerization) of the aforementioned monomers, etc., by energy (e.g., heat or light). The initiator may include a thermal initiator and / or a photoinitiator. The types of the thermal initiator include, but are not limited to, azobis-isobutyronitrile. The photoinitiator may include, but is not limited to, triazine compounds, acetophenone compounds, benzophenone compounds, thioxanthone compounds, benzoin compounds, oxime ester compounds, aminoketone compounds, phosphine or phosphine oxide compounds, carbazole compounds, diketone compounds, sulfonium borate compounds, diazo compounds, nonimidazole compounds, or combinations thereof. The types of each of the aforementioned initiators are known and are not particularly limited. In the above ink composition, the content of the initiator may be 0.1 wt% or more, 0.5 wt% or more, 1 wt% or more, 1.5 wt% or more, 2 wt% or more, 2.5 wt% or more, or 3 wt% or more based on the total solid content of the composition. In the above ink composition, the content of the initiator may be 10 wt% or less, 5 wt% or less, 4 wt% or less, 3 wt% or less, 2 wt% or less, 1 wt% or less, or 0.5 wt% or less based on the total solid content of the composition.

[0136] The ink composition may further comprise a dispersant. The dispersant may disperse quantum dots and / or metal oxide microparticles as described below. The dispersant may comprise a polymer. The dispersant may comprise a substituted or unsubstituted urethane polymer (e.g., polyurethane), a substituted or unsubstituted alkylene polymer (e.g., PE, PP, etc.), a substituted or unsubstituted poly(meth)acrylate, a substituted or unsubstituted epoxy polymer, a substituted or unsubstituted polyester, or a combination thereof. The dispersant or the polymer may, for example, comprise a carboxylic acid group, an amine group, or a combination thereof in its main chain. The dispersant may comprise a carbon-carbon double bond and may participate in the polymerization described below. The dispersant may be a compound (e.g., a polymer such as polyurethane) comprising a repeating unit represented by Formula A-1, Formula A-2, or Formula A-3:

[0137] [Chemical Formula A-1]

[0138]

[0139] [Chemical Formula A-2]

[0140]

[0141] [Chemical Formula A-3]

[0142]

[0143] In the above formulas, R1 and R2 are each independently substituted or unsubstituted alkylenes, and R3 is an organic group comprising an amine group, a carboxylic acid group, or a combination thereof.

[0144] The above-mentioned dispersant may exhibit an acid value and / or an amine value. In this specification, the acid value refers to the number of milligrams of KOH required to neutralize free fatty acids contained in 1 g of a given compound. Methods for determining the acid value are known. In this specification, the amine value refers to the amine content contained in a given compound. The amine value may be a value representing the titrated KOH consumption in mg per 1 g of amine. The amine value can be determined by known methods. An ink composition of one embodiment may exhibit a desired acid value and / or amine value by including the above-mentioned dispersant and / or the aforementioned first organic ligand and second organic ligand.

[0145] In one embodiment, the dispersant (or the first or second organic ligand, or the ink composition) may have an acid value of 5 mg KOH / g or less. In one embodiment, the dispersant (or the first or second organic ligand, or the ink composition) may have an acid value of 35 mg KOH / g or more, 40 mg KOH / g or more, 45 mg KOH / g or more, 50 mg KOH / g or more, 55 mg KOH / g or more, 60 mg KOH / g or more, 65 mg KOH / g or more, 70 mg KOH / g or more, 75 mg KOH / g or more, 80 mg KOH / g or more, 85 mg KOH / g or more, 90 mg KOH / g or more, 95 mg KOH / g or more, or 100 mg KOH / g or more. In one embodiment, the dispersant may have an acid value of 300 mg KOH / g or less, 250 mg KOH / g or less, 200 mg KOH / g or less, 180 mg KOH / g or less, 150 mg KOH / g or less, or 130 mg KOH / g or less, 110 mg KOH / g or less, 100 mg KOH / g or less, 90 mg KOH / g or less, 80 mg KOH / g or less, 70 mg KOH / g or less, 60 mg KOH / g or less, 50 mg KOH / g or less, or 45 mg KOH / g or less.

[0146] In one embodiment, the dispersant (or the first or second organic ligand or the ink composition) may have an amine value of 5 mg KOH / g or less. In one embodiment, the dispersant (or the first or second organic ligand or the ink composition) may have an amine value of 35 mg KOH / g or more.

[0147] In one embodiment, the dispersant (or the first or second organic ligand or the ink composition) may have an amine value of 35 mg KOH / g or more, 40 mg KOH / g or more, 45 mg KOH / g or more, 50 mg KOH / g or more, 55 mg KOH / g or more, 60 mg KOH / g or more, 65 mg KOH / g or more, 70 mg KOH / g or more, 75 mg KOH / g or more, 80 mg KOH / g or more, 85 mg KOH / g or more, 90 mg KOH / g or more, 95 mg KOH / g or more, or 100 mg KOH / g or more. In one embodiment, the dispersant may have an amine value of 300 mg KOH / g or less, 250 mg KOH / g or less, 200 mg KOH / g or less, 180 mg KOH / g or less, 150 mg KOH / g or less, or 130 mg KOH / g or less, 110 mg KOH / g or less, 100 mg KOH / g or less, 90 mg KOH / g or less, 80 mg KOH / g or less, 70 mg KOH / g or less, 60 mg KOH / g or less, or 50 mg KOH / g or less.

[0148] The above ink composition has both an acid value and an amine value, and the difference between the acid value and the amine value may be less than 5 mg KOH / g. The above ink composition has both an acid value and an amine value, and both the acid value and the amine value may be 35 mg KOH / g or higher.

[0149] The above ink composition may have an acid value in the range of 5 - 200 mg KOH / g, 10 - 180 mg KOH / g, 15 - 170 mg KOH / g, 20 - 160 mg KOH / g, 25 - 150 mg KOH / g, 30 - 140 mg KOH / g, 35 - 130 mg KOH / g, 40 - 120 mg KOH / g, 45 - 110 mg KOH / g, 50 - 100 mg KOH / g, 55 - 90 mg KOH / g, 60 - 80 mg KOH / g, 65 - 70 mg KOH / g, or a combination thereof.

[0150] The ink composition may have an amine value in the range of 5 - 200 mg KOH / g, 10 - 180 mg KOH / g, 15 - 170 mg KOH / g, 20 - 160 mg KOH / g, 25 - 150 mg KOH / g, 30 - 140 mg KOH / g, 35 - 130 mg KOH / g, 40 - 120 mg KOH / g, 45 - 110 mg KOH / g, 50 - 100 mg KOH / g, 55 - 90 mg KOH / g, 60 - 80 mg KOH / g, 65 - 70 mg KOH / g, or a combination thereof.

[0151] The dispersant capable of providing the aforementioned acid / amine value may include any dispersant used in the ink composition. Such dispersants (e.g., BYK-Chemie’s DisperByk series, Ajinomoto-Fine-Techno Co., Inc.’s EFKA series, etc.) are commercially available and can be appropriately selected considering the liquid vehicle, quantum dots, metal oxide microparticles, etc. to be used.

[0152] In the above ink composition, the content of the dispersant can be selected by taking into account the acid value / amine value of the final ink composition, the first / second organic ligand, the type of quantum dot, etc. In the above ink composition, the content of the dispersant may be 1 wt% or more, 5 wt% or more, 10 wt% or more, 15 wt% or more, 20 wt% or more, 25 wt% or more, 30 wt% or more, 35 wt% or more, or 40 wt% or more based on the total solid content. In the above ink composition, the content of the dispersant may be 70 wt% or less, 60 wt% or less, 55 wt% or less, 50 wt% or less, 45 wt% or less, 40 wt% or less, 35 wt% or less, 30 wt% or less, 25 wt% or less, 20 wt% or less, 15 wt% or less, 10 wt% or less, or 5 wt% or less based on the total solid content of the composition.

[0153] The ink composition may further include a plurality of metal oxide microparticles. The metal oxide microparticles may contribute to the improvement of optical properties (e.g., brightness improvement) of the quantum dot composite described below. The metal oxide microparticles may include titanium oxide, silicon oxide, barium oxide, zinc oxide, hafnium oxide, zirconium oxide, aluminum oxide, gallium oxide, indium oxide, germanium oxide, tin oxide, antimony oxide, scandium oxide, yttrium oxide, lanthanum oxide, ruthenium oxide, cerium oxide, tantalum oxide, niobium oxide, or a combination thereof. The average size of the metal oxide microparticles may be 150 nm or more, 180 nm or more, or 200 nm or more. The average size of the metal oxide microparticles may be 500 nm or less, 400 nm or less, 350 nm or less, or 300 nm or less.

[0154] In the above ink composition, the content of the metal oxide fine particles may be 1 weight% or more, 5 weight% or more, 10 weight% or more, 15 weight% or more, or 18 weight% or more based on the total solid content. In the above ink composition, the content of the metal oxide fine particles may be 25 weight% or less, 20 weight% or less, 15 weight% or less, 10 weight% or less, or 5 weight% or less based on the total solid content.

[0155] In another embodiment, the method for preparing the ink composition is,

[0156] A step of preparing a first solution comprising the first quantum dot and the organic solvent,

[0157] The method comprises the steps of: preparing a second solution comprising the second quantum dot and the liquid monomer; and mixing the first solution and the second solution substantially without precipitation (e.g., while maintaining a colloidal dispersion state).

[0158] The initiator, the dispersant, and the metal oxide microparticles may be included in the first solution, the second solution, or both.

[0159] Unlike organic pigments, the dispersion state of quantum dots (and, if present, metal oxide microparticles) in an ink composition can have a substantial effect on the luminescence properties and inkjet processability of the ink composition and the quantum dot composite produced therefrom. An ink composition of one embodiment can achieve a desired dispersion state (e.g., a colloidal dispersion state). As confirmed by the inventors, the acid value and amine value of the first solution and the second solution can have a substantial effect on the dispersion state of the final ink composition.

[0160] In one embodiment, the above method may have a first solution and a second solution corresponding to one of the following in order to maintain the dispersed state of the ink composition:

[0161] At least one of the first solution and the second solution does not exhibit both acid value and amine value;

[0162] If the first solution exhibits only one of the acid value and the amine value, the second solution also exhibits only one of the acid value and the amine value;

[0163] If the first solution exhibits both an acid value and an amine value, the second solution also exhibits both an acid value and an amine value;

[0164] In the case where one of the first solution and the second solution exhibits both acid value and amine value (i.e., amphoteric) and the other has only acid value or only amine value, in the amphoteric solution, the difference between the acid value and the amine value may be less than 5 mg KOH / g, or both the acid value and the amine value may be 35 mg KOH / g or more.

[0165] The acid value and amine value of the first solution and the second solution can be controlled to a desired value (e.g., to correspond to one of the aforementioned conditions) by the dispersant and / or the first and second organic ligands contained in each.

[0166] The content of the first quantum dot (or second quantum dot), if present, the initiator, dispersant, or metal oxide microparticles in the first solution (or second solution) can be appropriately selected in consideration of each component contained in the solution and the final ink composition.

[0167] In the ink composition of one embodiment, by having the aforementioned features, a quantum dot (composite) film or a pattern thereof can be provided, for example, by an inkjet method, and the manufactured film (or pattern) can exhibit improved physical properties (e.g., luminous efficiency or driving reliability when applied to a device). In the ink composition of one embodiment, quantum dots and, if present, metal oxide microparticles can exhibit an improved dispersion state. The ink composition can maintain a colloidal dispersion state. In the ink composition of one embodiment (or in the quantum dot composite described below), the dispersed phase is a solid, and the continuous medium can be a liquid (or solid). Here, "colloidal dispersion" may be a dispersion having dimensions of 1 nm or more (e.g., 10 nm or more, 50 nm or more, or 100 nm or more) and several μm or less (e.g., 5 μm or less, 4 μm or less, 3 μm or less, 2 μm or less, 1 μm or less, 900 nm or less, 800 nm or less, 700 nm or less, 600 nm or less, or 500 nm or less).

[0168] The ink composition of one embodiment can exhibit physical properties (e.g., viscosity) that are more suitable for an inkjet process by being prepared by mixing a first solution and a second solution.

[0169] In one embodiment, the ink composition may have a viscosity of 1 cPs or more, 3 cPs or more, 5 cPs or more, 7 cPs or more, 9 cPs or more, 11 cPs or more, 13 cPs or more, or 15 cPs or more. The viscosity may be 43 cPs or less, 40 cPs or less, 35 cPs or less, 30 cPs or less, 25 cPs or less, 20 cPs or less, 18 cPs or less, 15 cPs or less, 12 cPs or less, 10 cPs or less, or 7 cPs or less.

[0170] The above ink composition may have a surface tension of 15 mN / m or more, 20 mN / m or more, 25 mN / m or more, or 30 mN / m or more. The above surface tension may be 100 mN / m or less, 90 mN / m or less, 80 mN / m or less, 70 mN / m or less, 60 mN / m or less, 50 mN / m or less, 40 mN / m or less, or 35 mN / m or less. The above ink composition may have a vapor pressure of 2.5 mmHg or less, 2 mmHg or less, 1.5 mmHg or less, or 1 mmHg or less.

[0171] The above ink composition may have a residual film rate of 90% or more, for example, 91% or more, 92% or more, 93% or more, 94% or more, or 95% or more. The above residual film rate may be the residual film rate after 30 minutes have elapsed since polymerization (or curing) in, for example, an inkjet process. The above residual film rate may be the residual film rate after a predetermined time (e.g., 30 minutes) has elapsed since the ink was ejected into the atmosphere at room temperature.

[0172] The above residual film rate can be calculated by the following formula.

[0173] Residual film rate = [(Volume of ink film) / (Volume of ink filled in pixel area)] x 100

[0174] The volume of the ink film can be measured by a 3D surface profiler.

[0175] The ink volume can be calculated from the volume of ink dispensed.

[0176] The ink composition may exhibit enhanced quantum efficiency. In one embodiment, quantum dots within the ink composition (or the composite described below) may exhibit a quantum efficiency of 30% or more, 40% or more, 50% or more, 60% or more, or 65% or more. Quantum efficiency can be measured, for example, by the absolute or relative method, using a commercially available spectrophotometer.

[0177] The film percentage can be measured at room temperature. The film percentage can be measured in an atmospheric environment.

[0178] The above ink composition can relatively mitigate the overshoot phenomenon of luminescence properties (e.g., luminescence efficiency) compared to a composition containing only ligand-exchanged quantum dots (e.g., by including different ligands as described above). Accordingly, the ink composition of one embodiment can be configured such that the relative luminescence efficiency to the initial luminescence efficiency of the quantum dot composite is 104% or less, e.g., 103% or less, or 102% or less, when irradiated with excitation light of a wavelength of 450 nm at a temperature of 60°C for 100 hours (in a solid state, e.g., in the state of a quantum dot (composite) film or pattern formed by polymerization).

[0179] The above ink composition may take the form of a film (or its pattern) through any coating process (e.g., spin coating, slit coating, or inkjet coating). A quantum dot composite film (or pattern) may be provided by an inkjet printing (or coating) method of one embodiment. When using an inkjet method, the ink composition of one embodiment is discharged onto a substrate (or a pixel area). The ink composition of one embodiment may form a film or pattern using the inkjet equipment (refer to the manual provided by the equipment manufacturer) (e.g., at 20-30 degrees Celsius or room temperature without increasing the temperature).

[0180] The obtained film (or pattern) can be subjected to polymerization (or curing) (optional drying and) to provide a solid-state quantum dot composite (or pattern). Equipment for the inkjet process is known and commercially available. Polymerization (or curing) conditions (temperature, time, atmosphere, etc.) can be appropriately selected in consideration of the types of liquid monomers and initiators contained in the ink and are not limited. In one embodiment, polymerization (or curing) may involve thermal polymerization or photopolymerization.

[0181] A quantum dot complex of one embodiment comprises a matrix and a plurality of quantum dots dispersed within the matrix, wherein the plurality of quantum dots comprises a first quantum dot comprising a first ligand and a second quantum dot comprising a second ligand different from the first ligand, and wherein the quantum dot complex is configured to emit light of a predetermined wavelength (e.g., by photoexcitation) and to exhibit a relative EQE with respect to the initial external quantum efficiency (EQE) of 104% or less while irradiating with excitation light of a wavelength of 450 nm at a temperature of 60 degrees Celsius for 100 hours.

[0182] The light of the aforementioned predetermined wavelength may be green light or red light. The matrix may comprise a cross-linked polymer (e.g., a polymer product of the aforementioned liquid monomer). The matrix may or may not comprise a linear polymer having carboxylic acid groups in repeating units (e.g., a polymer having a relatively high acid value of 50 mg KOH / g to 200 mg KOH / g), a cardo binder resin, or a combination thereof. The quantum dot complex may be prepared from the aforementioned ink composition. Accordingly, the matrix may further comprise the aforementioned dispersant. The quantum dot complex may further comprise the aforementioned metal oxide microparticles.

[0183] The quantum dot composite may be in the form of a (patterned) film. The thickness of the film may be 1 micrometer (um) or more, 5 um or more, 6 um or more, 7 um or more, 8 um or more, or 9 um or more. It may be up to 20 um or less, 6 um or less, 10 um or less, or 8 um or less.

[0184] The quantum dot composite may have a vaporized inorganic content. In one embodiment, the quantum dot composite may have an inorganic content of 50 wt% or more, 55 wt% or more, 57 wt% or more, 58 wt% or more, 59 wt% or more, 60 wt% or more, 61 wt% or more, 62 wt% or more, 63 wt% or more, 64 wt% or more, 65 wt% or more, 66 wt% or more, 67 wt% or more, 68 wt% or more, 69 wt% or more, or 70 wt% or more, based on the total weight of the composite.

[0185] The specific details regarding the first and second quantum dots, liquid monomers, dispersants, metal oxide microparticles, etc., are as described above.

[0186] A quantum dot composite (film or pattern) obtained from the ink composition of one embodiment can be used in a color conversion panel and a display panel including the same.

[0187] In one embodiment, the color conversion panel comprises a color conversion layer including a color conversion zone (e.g., disposed on a substrate) and, optionally, a partition defining each zone of the color conversion layer. The color conversion zone includes a first zone comprising a quantum dot (polymer) complex and emitting a first light. The color conversion zone may further include a second zone emitting a second light different from the first light and comprising a quantum dot complex.

[0188] The first light and the second light have different maximum emission peak wavelengths in the photoluminescence spectrum. In one embodiment, the first light may be red light with a maximum emission peak wavelength of 600 nm to 670 nm (e.g., 620 nm to 650 nm), and the second light may be green light with a maximum emission peak wavelength of 500 nm to 580 nm (e.g., 500 nm to 550 nm).

[0189] In another embodiment, the display panel includes a light-emitting panel, a color-converting panel, and a light-transmitting layer located between the light-emitting panel and the color-converting panel. The display panel may further include a bonding material that combines the light-emitting panel and the color-converting panel.

[0190] Below, the display panel and color conversion panel will be described with reference to the drawings.

[0191] Referring to FIGS. 1 and 2, a display panel (1000) according to one embodiment includes a light-emitting panel (100), a color-converting panel (200), a light-transmitting layer (300) located between the light-emitting panel (100) and the color-converting panel (200), and a bonding material (400) that combines the light-emitting panel (100) and the color-converting panel (200).

[0192] The light-emitting panel (100) and the color-converting panel (200) face each other with a light-transmitting layer (300) in between, and the color-converting panel (200) is positioned in the direction in which light is emitted from the light-emitting panel (100). A bonding material (400) is positioned along the edges of the light-emitting panel (100) and the color-converting panel (200), and may be, for example, a sealing material.

[0193] Referring to FIG. 3, a display panel (1000) according to one embodiment includes a display area (1000D) for displaying an image and a non-display area (1000P) located around the display area (1000D) and having a bonding material (400) disposed therein.

[0194] The display area (1000D) includes a plurality of pixels (PX) arranged along a row (e.g., x direction) and / or a column (e.g., y direction), and each pixel (PX) includes a plurality of subpixels (PX1, PX2, PX3) that display different colors. Here, as an example, a configuration in which three subpixels (PX1, PX2, PX3) form a single pixel is illustrated, but it is not limited thereto and may include additional subpixels such as a white subpixel, or one or more subpixels that display the same color. The plurality of pixels (PX) may be arranged, for example, in a Bayer matrix, a PenTile matrix and / or a diamond matrix, but is not limited thereto.

[0195] Each subpixel (PX1, PX2, PX3) can display three primary colors or a combination of three primary colors, for example, red, green, blue, or a combination thereof. For example, the first subpixel (PX1) can display red, the second subpixel (PX2) can display green, and the third subpixel (PX3) can display blue.

[0196] Although the drawings illustrate an example in which all subpixels have the same size, they are not limited thereto, and at least one of the subpixels may be larger or smaller than another subpixel. Although the drawings illustrate an example in which all subpixels have the same shape, they are not limited thereto, and at least one of the subpixels may have a different shape from another subpixel.

[0197] Referring to FIG. 4, the light-emitting panel (100) and the color-converting panel (200) will be described in order.

[0198] A light-emitting panel (100) may include a light-emitting element that emits light in a predetermined wavelength range and a circuit element for switching and / or driving the light-emitting element, and specifically includes a lower substrate (110), a buffer layer (111), a thin-film transistor (TFT), a light-emitting element (180), and an encapsulation layer (190).

[0199] The lower substrate (110) may be a glass substrate or a polymer substrate, and the polymer substrate may include, for example, polyimide, polyamide, polyamideimide, polyethylene terephthalate, polyethylene naphthalene, polymethyl methacrylate, polycarbonate, copolymers thereof or combinations thereof, but is not limited thereto.

[0200] The buffer layer (111) may include organic, inorganic, or organic-inorganic materials, such as oxides, nitrides, or oxynitrides, such as silicon oxide, silicon nitride, silicon oxynitride, or a combination thereof, but is not limited thereto. The buffer layer (111) may be one layer or two or more layers and may cover the entire surface of the lower substrate (110). The buffer layer (111) may be omitted.

[0201] A thin-film transistor (TFT) may be a three-terminal device for switching and / or driving a light-emitting element (180) described later, and may include one or more for each subpixel. The thin-film transistor (TFT) includes a gate electrode (124), a semiconductor layer (154) overlapping with the gate electrode (124), a gate insulating film (140) located between the gate electrode (124) and the semiconductor layer (154), and a source electrode (173) and a drain electrode (175) electrically connected to the semiconductor layer (154). In the drawings, a coplanar top gate structure is shown as an example, but it is not limited thereto and may have various structures.

[0202] The gate electrode (124) is electrically connected to a gate wire (not shown) and may include, but is not limited to, a low-resistance metal such as aluminum (Al), molybdenum (Mo), copper (Cu), titanium (Ti), silver (Ag), gold (Au), alloys thereof, or combinations thereof.

[0203] The semiconductor layer (154) may be an inorganic semiconductor such as amorphous silicon, polycrystalline silicon, or oxide semiconductor; an organic semiconductor; an organic-inorganic semiconductor; or a combination thereof. As an example, the semiconductor layer (154) may include an oxide semiconductor comprising at least one of indium (In), zinc (Zn), tin (Sn), and gallium (Ga), and the oxide semiconductor may include, for example, indium-gallium-zinc oxide, zinc-tin oxide, or a combination thereof, but is not limited thereto. The semiconductor layer (154) may include a channel region and a doping region disposed on both sides of the channel region and electrically connected to the source electrode (173) and the drain electrode (175), respectively.

[0204] The gate insulating film (140) may include organic, inorganic, or organic-inorganic materials, such as oxides, nitrides, or oxynitrides, such as silicon oxide, silicon nitride, silicon oxynitride, or a combination thereof, but is not limited thereto. Although the drawing shows an example in which the gate insulating film (140) is formed on the front surface of the lower substrate (110), it is not limited thereto and may be selectively formed between the gate electrode (124) and the semiconductor (154). The gate insulating film (140) may be one layer or two or more layers.

[0205] The source electrode (173) and the drain electrode (175) may include, but are not limited to, low-resistance metals such as aluminum (Al), molybdenum (Mo), copper (Cu), titanium (Ti), silver (Ag), gold (Au), alloys thereof, or combinations thereof. The source electrode (173) and the drain electrode (175) may each be electrically connected to a doping region of the semiconductor layer (154). The source electrode (173) is electrically connected to a data line (not shown), and the drain electrode (175) is electrically connected to a light-emitting element (180) described later.

[0206] An interlayer insulating film (145) is additionally formed between the gate electrode (124) and the source / drain electrodes (173, 175). The interlayer insulating film (145) may include organic, inorganic, or organic-inorganic materials, such as oxides, nitrides, or oxynitrides, such as silicon oxide, silicon nitride, silicon oxynitride, or a combination thereof, but is not limited thereto. The interlayer insulating film (145) may be one layer or two or more layers.

[0207] A protective film (160) is formed on the thin-film transistor (TFT). The protective film (160) may be, for example, a passivation film. The protective film (160) may include organic, inorganic, or organic-inorganic materials, and may include, for example, polyacrylic, polyimide, polyamide, polyamideimide, or a combination thereof, but is not limited thereto. The protective film (160) may be one layer or two or more layers.

[0208] A light-emitting element (180) may be placed in each subpixel (PX1, PX2, PX3), and the light-emitting element (180) placed in each subpixel (PX1, PX2, PX3) may be driven independently. The light-emitting element (180) may be, for example, a light-emitting diode and may include a light-emitting layer located between a pair of electrodes. The light-emitting layer may include a light-emitting body capable of emitting light in a predetermined wavelength range, for example, a light-emitting body that emits light of a first light-emitting spectrum belonging to the visible light wavelength spectrum. The light-emitting body may include an organic light-emitting body, an inorganic light-emitting body, an organic-inorganic light-emitting body, or a combination thereof, and may be one or more of two types.

[0209] The light-emitting element (180) may be, for example, an organic light-emitting diode, an inorganic light-emitting diode, or a combination thereof, and the inorganic light-emitting diode may include, for example, a quantum dot light-emitting diode, a perovskite light-emitting diode, a micro light-emitting diode, an inorganic nano light-emitting diode, or a combination thereof, but is not limited thereto.

[0210] Figure 5 is a cross-sectional view showing a non-limiting example of a light-emitting element.

[0211] Referring to FIG. 5, the light-emitting element (180) includes a first electrode (181) and a second electrode (182) facing each other; a light-emitting layer (183) located between the first electrode (181) and the second electrode (182); and optionally, auxiliary layers (184, 185) located between the first electrode (181) and the light-emitting layer (183) and between the second electrode (182) and the light-emitting layer (183).

[0212] The first electrode (181) and the second electrode (182) may be arranged facing each other along the thickness direction (e.g., z-direction), and either the first electrode (181) or the second electrode (182) may be an anode and the other a cathode. The first electrode (181) may be a light-transmitting electrode, a semi-transparent electrode, or a reflective electrode, and the second electrode (182) may be a light-transmitting electrode or a semi-transparent electrode. The light-transmitting electrode or semi-transmitting electrode may be made of a thin single-layer or multi-layer metal film including, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), tin oxide (SnO), aluminum tin oxide (AlTO), and fluorine-doped tin oxide (FTO), or silver (Ag), copper (Cu), aluminum (Al), magnesium (Mg), magnesium-silver (Mg-Ag), magnesium-aluminum (Mg-Al), or a combination thereof. The reflective electrode may include a metal, a metal nitride, or a combination thereof, and may include, for example, silver (Ag), copper (Cu), aluminum (Al), gold (Au), titanium (Ti), chromium (Cr), nickel (Ni), alloys thereof, nitrides thereof (e.g., TiN), or a combination thereof, but is not limited thereto.

[0213] The light-emitting layer (183) may include a light-emitting body capable of emitting a third light. The emission spectrum of the third light may belong to a relatively short wavelength region of the visible light wavelength spectrum, for example, a blue emission spectrum. The maximum emission peak wavelength of the third light may belong to a wavelength region of about 400 nm or more and less than 500 nm, and within the above range, may belong to a wavelength region of about 410 nm to 490 nm or about 420 nm to 480 nm. The light-emitting body may be one type or two or more types.

[0214] For example, the light-emitting layer (183) may include a host material and a dopant material.

[0215] For example, the light-emitting layer (183) may include a phosphorescent material, a fluorescent material, or a combination thereof.

[0216] For example, the light emitter may include an organic light emitter, and the organic light emitter may be a low-molecular-weight compound, a polymer, or a combination thereof. When the light emitter includes an organic light emitter, the light-emitting element (180) may be an organic light-emitting diode.

[0217] For example, the light emitter may include an inorganic light emitter, and the inorganic light emitter may be an inorganic semiconductor, a quantum dot, a perovskite, or a combination thereof. When the light emitter includes an inorganic light emitter, the light-emitting element (180) may be a quantum dot light-emitting diode, a perovskite light-emitting diode, or a micro light-emitting diode.

[0218] The auxiliary layers (184, 185) may each be located between the first electrode (181) and the light-emitting layer (183) and between the second electrode (182) and the light-emitting layer (183), and may each be a charge auxiliary layer for controlling the injection and / or mobility of charge. The auxiliary layers (184, 185) may each be one layer or two or more layers, and may be, for example, a hole injection layer, a hole transport layer, an electron blocking layer, an electron injection layer, an electron transport layer, a hole blocking layer, or a combination thereof. At least one of the auxiliary layers (184, 185) may be omitted.

[0219] The light-emitting elements (180) placed in each subpixel (PX1, PX2, PX3) may be the same or different from each other. The light-emitting elements (180) placed in each subpixel (PX1, PX2, PX3) may emit light of the same light emission spectrum, for example, each may emit light of a blue light emission spectrum, for example, light of a blue light emission spectrum having a maximum light emission wavelength in the wavelength range of about 400 nm or more and less than 500 nm, about 410 nm to 490 nm, or about 420 nm to 480 nm. The light-emitting elements (180) placed in each subpixel (PX1, PX2, PX3) may be separated by a pixel defining film (not shown).

[0220] Referring again to FIGS. 1 to 4, the encapsulation layer (190) covers the light-emitting element (180) and may include a glass plate, a metal thin film, an organic film, an inorganic film, an organic-inorganic film, or a combination thereof. The organic film may include, for example, an acrylic resin, (meth)acrylic resin, polyisoprene, vinyl resin, epoxy resin, urethane resin, cellulose resin, perylene resin, or a combination thereof, but is not limited thereto. The inorganic film may include, for example, an oxide, a nitride and / or an oxynitride, and may be, for example, silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, aluminum oxynitride, zirconium oxide, zirconium nitride, zirconium oxynitride, titanium oxide, titanium nitride, titanium oxynitride, hafnium oxide, hafnium nitride, hafnium oxynitride, tantalum oxide, tantalum nitride, tantalum oxynitride, lithium fluoride, or a combination thereof, but is not limited thereto. The organic or inorganic membrane may include, for example, polyorganosiloxane, but is not limited thereto. The encapsulation layer (190) may be one layer or two or more layers.

[0221] The color conversion panel (200) can convert light of a third emission spectrum (e.g., blue light) supplied from the light-emitting panel (100) into light of a first or second emission spectrum different from the third emission spectrum (e.g., red light or green light) and emit it toward an observer (not shown), and specifically includes an upper substrate (210), a light-blocking pattern (220), a color filter layer (230), a flattening layer (240), a partition (250), a color conversion layer (270), and an encapsulation layer (290).

[0222] The upper substrate (210) may be a glass substrate or a polymer substrate, and the polymer substrate may include, for example, polyimide, polyamide, polyamideimide, polyethylene terephthalate, polyethylene naphthalene, polymethyl methacrylate, polycarbonate, copolymers thereof or combinations thereof, but is not limited thereto.

[0223] The color conversion layer (270) faces the light-emitting element (180) of the light-emitting panel (100). The color conversion layer (270) may include at least one color conversion zone that converts the light emission spectrum of light supplied from the light-emitting panel (100) into a different light emission spectrum, and the color conversion zone may, for example, convert light of the light emission spectrum supplied from the light-emitting panel (100) into light of the light emission spectrum of a color displayed at each subpixel (PX1, PX2, PX3).

[0224] The color conversion zone can be converted into light of the wavelength spectrum of the color displayed at each subpixel (PX1, PX2, PX3) and emitted, and accordingly, the quantum dots included in each color conversion zone may be different from each other.

[0225] Referring to FIG. 4, at least a portion of the color conversion layer (270) may include quantum dots, and for example, the color conversion layer (270) may include a first color conversion zone (270a) included in a first subpixel (PX1) and including a first quantum dot (271a), a second color conversion zone (270b) included in a second subpixel (PX2) and including a second quantum dot (271b), and a light-transmitting zone (270c).

[0226] The first quantum dot (271a) included in the first color conversion zone (270a) can convert light of the third emission spectrum emitted from the light-emitting panel (100) into light of the first emission spectrum that is the same as the wavelength spectrum of the color displayed in the first subpixel (PX1). The first emission spectrum may be different from the third emission spectrum and may be a longer wavelength spectrum than the third emission spectrum.

[0227] The second quantum dot (271b) included in the second color conversion zone (270b) can convert light of the third emission spectrum emitted from the light-emitting panel (100) into light of the second emission spectrum that is identical to the wavelength spectrum of the color displayed in the second subpixel (PX2). The second emission spectrum may be different from the third and first emission spectra, respectively, and may be a longer wavelength spectrum than the third emission spectrum.

[0228] For example, when the light-emitting element (180) of the light-emitting panel (100) emits light of a blue light emission spectrum and the first subpixel (PX1), the second subpixel (PX2), and the third subpixel (PX3) each display red, green, and blue, the first quantum dot (271a) included in the first color conversion zone (270a) can convert light of a blue light emission spectrum into light of a red light emission spectrum, and the second quantum dot (271b) included in the second color conversion zone (270b) can convert light of a blue light emission spectrum into light of a green light emission spectrum. At this time, since the first quantum dot (271a) emits light of a longer wavelength spectrum than the second quantum dot (271b), the size of the first quantum dot (271a) may be larger than the size of the second quantum dot (271b). Since the blue color displayed in the third subpixel (PX3) can be displayed by light of a blue light emission spectrum emitted from the light-emitting element (180) of the light-emitting panel (100), the third subpixel (PX3) can be displayed through the light-emitting area (270c) without a separate color converter (quantum dot). However, the third subpixel (PX3) may also include a color converter, such as a quantum dot, that emits light of a blue light emission spectrum.

[0229] The first color conversion zone (270a), the second color conversion zone (270b), and the light transmission zone (270c) may each further include scattering particles (272a, 272b, 272c). The scattering particles (272a, 272b, 272c) may scatter and / or reflect light emitted from quantum dots (271a, 271b) and / or light-emitting elements (180) of the light-emitting panel (100) to guide it to the color filter layer (230). The scattering particles (272a, 272b, 272c) may be low-refractive-index nanoparticles, such as silicon oxide, titanium oxide, or a combination thereof, but are not limited thereto.

[0230] The first color conversion zone (270a), the second color conversion zone (270b), and the light-transmitting zone (270c) may each further include a light-transmitting resin (273a, 273b, 273c). The light-transmitting resin (273a, 273b, 273c) may be a dispersion medium that disperses quantum dots (271a, 271b) and / or scattering particles (272a, 272b, 272c), and may be, for example, an acrylic resin, a urethane resin, a silicone resin, an epoxy resin, a cardo-based resin, an imide resin, a derivative thereof, or a combination thereof, but is not limited thereto.

[0231] The partition wall (250) can define each zone of the color conversion layer (270) and can be located between adjacent zones. For example, the partition wall (250) can define the aforementioned first color conversion zone (270a), second color conversion zone (270b), and light transmission zone (270c), respectively, and can be located between adjacent first color conversion zone (270a) and second color conversion zone (270b), between adjacent second color conversion zone (270b) and light transmission zone (270c), and between adjacent first color conversion zone (270a) and light transmission zone (270c), respectively. The partition wall (250) provides a space to supply a composition for the color conversion layer (270) and, at the same time, prevents the compositions of each of the first color conversion zone (270a), the second color conversion zone (270b), and the light transmission zone (270c) from overflowing and mixing into adjacent first color conversion zone (270a), second color conversion zone (270b), and light transmission zone (270c) during the process of forming the first color conversion zone (270a), the second color conversion zone (270b), and the light transmission zone (270c).

[0232] The partition wall (250) may be in direct contact with the first color conversion zone (270a), the second color conversion zone (270b), and the light-transmitting zone (270c), and there may not be any separate layers interposed between the partition wall (250) and the first color conversion zone (270a), between the partition wall (250) and the second color conversion zone (270b), and between the partition wall (250) and the light-transmitting zone (270c).

[0233] In the drawing, a column-shaped partition (250) having the same width is shown as an example, but it is not limited thereto and the partition (250) can have various sizes and shapes. For example, the partition (250) can have a trapezoidal cross-sectional shape.

[0234] The color filter layer (230) is positioned in the direction in which light passing through the color conversion layer (270) is emitted. The color filter layer (230) may include color filters (230a, 230b, 230c) that selectively transmit light of different wavelength spectra placed in each subpixel (PX1, PX2, PX3). The color filters (230a, 230b, 230c) may selectively transmit light of the same wavelength spectra as the color displayed in each subpixel (PX1, PX2, PX3), and may selectively transmit light of the emission spectra converted in each section of the color conversion layer (270).

[0235] For example, when a first subpixel (PX1), a second subpixel (PX2), and a third subpixel (PX3) each display red, green, and blue, and light of a red emission spectrum, a green emission spectrum, and a blue emission spectrum is emitted in a first color conversion zone (270a), a second color conversion zone (270b), and a light-emitting zone (270c), respectively, a first color filter (230a) superimposed on the first color conversion zone (270a) may be a red filter, a second color filter (230b) superimposed on the second color conversion zone (270b) may be a green filter, and a third color filter (230c) superimposed on the light-emitting zone (270c) may be a blue filter. The first color filter (230a), the second color filter (230b), or the third color filter (230c) may each include a pigment or dye that selectively transmits light of a red wavelength spectrum, a green wavelength spectrum, or a blue wavelength spectrum and absorbs and / or reflects light of the remaining wavelength spectrum.

[0236] The color filter layer (230) can more precisely filter the light emitted from the color conversion layer (270) to increase the color purity of the light emitted toward the upper substrate (210). For example, the first color filter (230a) located in overlap with the first color conversion zone (270a) can increase the color purity of light, for example, of a red emission spectrum by blocking light that passes through without being converted by the first quantum dot (271a) of the first color conversion zone (270a). For example, the second color filter (230b) located in overlap with the second color conversion zone (270b) can increase the color purity of light, for example, of a green emission spectrum by blocking light that passes through without being converted by the second quantum dot (271b) of the second color conversion zone (270b). For example, a third color filter (230c) located overlapping with the light-emitting area (270c) can increase the color purity of the light of the blue light-emitting spectrum by blocking light other than the light of the blue light-emitting spectrum. For example, at least some of the first, second, and third color filters (230a, 230b, 230c) may be omitted, and for example, the third color filter (230c) located overlapping with the light-emitting area (270c) may be omitted.

[0237] The light-blocking pattern (220) can partition each subpixel (PX1, PX2, PX3) and can be located between adjacent subpixels (PX1, PX2, PX3). The light-blocking pattern (220) can be, for example, a black matrix. The light-blocking pattern (220) can overlap with the edges of adjacent color filters (230a, 230b, 230c).

[0238] The flattening layer (240) may be located between the color filter layer (230) and the color conversion layer (270) and may reduce or eliminate the step difference caused by the color filter layer (230). The flattening layer (240) may include organic materials, inorganic materials, organic-inorganic materials, or a combination thereof, such as oxides, nitrides, or oxynitrides, such as silicon oxide, silicon nitride, silicon oxynitride, or a combination thereof, but is not limited thereto. The flattening layer (240) may be one layer or two or more layers and may cover the entire surface of the upper substrate (210).

[0239] The encapsulation layer (290) covers the color conversion layer (270) and the partition (250) and may include a glass plate, a metal thin film, an organic film, an inorganic film, an organic-inorganic film, or a combination thereof. The organic film may include, for example, an acrylic resin, (meth)acrylic resin, polyisoprene, vinyl resin, epoxy resin, urethane resin, cellulose resin, perylene resin, or a combination thereof, but is not limited thereto. The inorganic film may include, for example, an oxide, a nitride and / or an oxynitride, and may be, for example, silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, aluminum oxynitride, zirconium oxide, zirconium nitride, zirconium oxynitride, titanium oxide, titanium nitride, titanium oxynitride, hafnium oxide, hafnium nitride, hafnium oxynitride, tantalum oxide, tantalum nitride, tantalum oxynitride, lithium fluoride, or a combination thereof, but is not limited thereto. The organic or inorganic membrane may include, for example, polyorganosiloxane, but is not limited thereto. The encapsulation layer (290) may be one layer or two or more layers.

[0240] A light-transmitting layer (300) may be interposed between the light-emitting panel (100) and the color-converting panel (200). The light-transmitting layer (300) may be, for example, a filler material and may include, for example, an organic material, an inorganic material, an organic-inorganic material, or a combination thereof, and may include, for example, an epoxy resin, a silicone compound, a polyorganosiloxane, or a combination thereof, but is not limited thereto.

[0241] The aforementioned display panel (1000) can be applied to various electronic devices including display devices, such as display devices such as TVs, monitors, computers, tablet PCs, and mobile phones, or lighting devices such as light sources.

[0242] Specific embodiments of the invention are presented below. However, the embodiments described below are merely for the purpose of specifically illustrating or explaining the invention and should not limit the scope of the invention.

[0243] [Example]

[0244] Analysis method

[0245] [1] Measurement of external quantum efficiency (EQE) of quantum dot complexes

[0246] External quantum efficiency is measured according to the following formula using commercially available quantum efficiency measuring equipment (e.g., equipped with an integrating sphere) (e.g., QY meter manufactured by Hamamatsu Corporation). When measuring quantum efficiency, the excitation light can be arbitrarily selected within the range of 400 nm to 680 nm (e.g., 450 nm), taking into account the optical properties of the given quantum dots:

[0247] External Quantum Efficiency = [A / B] x 100 (%)

[0248] A: Number of photons emitted from the complex

[0249] B: Number of photons of excitation light (provided to the complex)

[0250] [2] Viscosity of the composition

[0251] The viscosity of the composition is measured using a viscometer or rheometer at room temperature (e.g., 25°C).

[0252] [3] Residual film rate measurement

[0253] The residual film rate is measured at room temperature and in the atmosphere using the following formula.

[0254] [(Volume of ink film) / (Volume of ink filled in pixel area)] x 100

[0255] Reference Example 1

[0256] Quantum dots are prepared according to a known method. Indium acetate and tris(trimethylsilyl)phosphine are reacted in 1-octadecene in the presence of palmitic acid to synthesize an InP core. The obtained core is dispersed in toluene. Zinc acetate, oleic acid, and trioctylamine are vacuum-treated in a reaction flask under elevated temperature to obtain a zinc precursor. A toluene dispersion of the InP core and a predetermined amount of S precursor are placed in the reaction flask and reacted at 280°C, after which the reaction solution is rapidly cooled to room temperature to obtain a reaction product containing InP / ZnS core-shell quantum dots.

[0257] Excess ethanol is added to the above reaction mixture and centrifuged. After centrifugation, the supernatant is discarded, and the precipitate is dried to obtain a quantum dot having oleic acid as an organic ligand on its surface (hereinafter referred to as the first quantum dot). It is confirmed that the first quantum dot emits red light.

[0258] Reference Example 2

[0259] A first quantum dot prepared in Reference Example 1 is subjected to a ligand exchange reaction under known conditions to obtain a second quantum dot comprising a second ligand represented by the following formula:

[0260]

[0261] Comparative Example 1

[0262] (1) Preparation of ink composition:

[0263] A second solution is prepared comprising a liquid monomer containing hexamethylene diacrylate, tetraethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, or tripropylene glycol diacrylate, and a second quantum dot and titanium oxide microparticles (average particle size approximately 200 nm) dispersed in said liquid monomer. The total solid content of the second solution is 100%.

[0264] Based on the total solid content in the second solution, the content of quantum dots is 43 wt% and the content of titanium oxide is 10 wt%.

[0265] (2) The prepared ink composition is ejected using an inkjet device at a predetermined temperature, and a photograph thereof is shown in FIG. 6a. It is confirmed that the jetting characteristics are poor even when the temperature is raised.

[0266] A film was manufactured using an inkjet method from the manufactured ink composition and left in the atmosphere at room temperature for 30 minutes to measure the residual film rate, and the results are shown in Figure 7.

[0267] (3) The prepared ink composition is ejected using an inkjet device and cured after exposure to obtain a solid-state quantum dot (polymer) composite. The external quantum efficiency of the obtained quantum dot composite is measured at 60°C using 450 nm light, and the change in external quantum efficiency over time is graphed in FIG. 8. From the results in FIG. 8, it is confirmed that the prepared composite can exhibit significant overshoot under device operating conditions.

[0269] Example 1:

[0270] (1) Preparation of ink composition:

[0271] A first solution is obtained containing a first quantum dot dispersed in an organic solvent (cyclohexyl acetate (CHA, vapor pressure 1.295 mmHg at 25°C) or propylene glycol monomethyl ether acetate (PGMEA, vapor pressure 3.7 mmHg at 20°C)).

[0272] An ink composition (hereinafter referred to as the second solution) is obtained in the same manner as Comparative Example 1.

[0273] An ink composition is prepared by mixing the first solution and the second solution in a weight ratio of 20:80. It is confirmed that the obtained composition maintains a good (colloidal) dispersion state without precipitation.

[0274] The viscosity of the manufactured ink composition is 17.9 cPs, and the vapor pressure at 20°C is 10 -3 The surface tension at 23°C is 35 mmHg or less. The acid value and amine value of the prepared ink composition are each 30-50 mg KOH / g.

[0275] (2) The prepared ink composition is ejected using an inkjet device, and a photograph of it is shown in FIG. 6b.

[0276] The first solution and the ink composition were extruded using an inkjet device to obtain a film, and the obtained film was left in an atmospheric environment at room temperature for 30 minutes to measure the residual film rate, and the results are shown in FIG. 7. From the results in FIG. 7, it is confirmed that the ink composition of the example can achieve a residual film rate equivalent to that of the composition of Comparative Example 1, which is liquid monomer-based (solvent-free). In contrast, it is confirmed that the first solution exhibits a significantly reduced residual film rate within a short period of time.

[0277] (3) The prepared ink composition is ejected using an inkjet device and cured after exposure to obtain a solid-state quantum dot (polymer) composite. The external quantum efficiency of the obtained quantum dot composite is measured, and the change in external quantum efficiency over time relative to the initial efficiency (100%) is graphed in FIG. 8. From the results of FIG. 8, it is confirmed that the quantum dot composite prepared from the ink composition of the example can significantly mitigate the overshoot phenomenon under device operating conditions.

[0278] Experimental Example 1:

[0279] Compositions (Compositions 1 to 8) are prepared in a manner similar to Example 1, while adjusting the dispersant so that the first solution and the second solution exhibit acid and amine values ​​satisfying the conditions of the table below. The dispersion state of each prepared composition is visually inspected, and the results are summarized together in Table 1.

[0280] Solution 1 Solution 2 Distributed state Composition 1 Only acid value or amine value exists Only acid value or amine value exists No sedimentation Composition 2 Ambidextrous 주1) Ambidextrous No sedimentation Composition 3 Only acid value or amine value exists It is amphoteric, with a difference between them of 5 mg KOH / g or more, and acid value and / or amine value less than 35 mg KOH / g. sedimentation Composition 4 Only acid value or amine value exists Amphoteric, with a difference between acid value and amine value of less than 5 mg KOH / g No sedimentation Composition 5 Amphoteric, with an acid value of 35 mg KOH / g or higher and an amine value of 35 mg KOH / g or higher No sedimentation Composition 6 It is amphoteric, with a difference between them of 5 mg KOH / g or more, and acid value and / or amine value less than 35 mg KOH / g. Only acid value or amine value exists sedimentation Composition 7 Amphoteric, with a difference between acid value and amine value of less than 5 mg KOH / g Only acid value or amine value exists No sedimentation Composition 8 Amphoteric, with an acid value of 35 mg KOH / g or higher and an amine value of 35 mg KOH / g or higher Only acid value or amine value exists No sedimentation

[0281] 주1) Amphoteric: When possessing both acid and amine values

[0282] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention. Explanation of the symbols

[0283] 100: Light-emitting panel 110: Lower substrate 111: Buffer layer 124: Gate electrode 140: Gate insulating film 154: Semiconductor layer 160: Protective layer 173: Source electrode 175: Drain electrode 200: Color conversion panel 210: Upper substrate 220: Light-shielding pattern 230: Color filter layer 250: Partition wall 270: Color conversion layer 270a: First color conversion zone 270b: Second color conversion zone 270c: Floodlight zone 271a: First quantum dot 271b: Second quantum dot 272a, 272b, 272c: Spawners 273a, 273b, 273c: Translucent resin 190, 290: Encapsulation layer 300: Transparency layer 1000: Display panel

Claims

Claim 1 An ink composition comprising a plurality of quantum dots, a liquid monomer, an initiator, and optionally an organic solvent, wherein the plurality of quantum dots comprises a first quantum dot comprising a first ligand and a second quantum dot comprising a second ligand different from the first ligand, and the ink composition is configured to emit a first light, and the ink composition has both an acid value and an amine value, wherein both the acid value and the amine value are 35 mg KOH / g or higher, or the difference between the acid value and the amine value is 5 mg KOH / g or lower. Claim 2 An ink composition according to claim 1, wherein the first light is green light, red light, or blue light, and the maximum emission peak of the first light has a full width at half maximum of 45 nm or less. Claim 3 In claim 1, the first ligand or the second ligand comprises RCOOH, RNH2, R2NH, R3N, RSH, R3PO, R3P, ROH, RCOOR', RPO(OH)2, RHPOOH, R2POOH, a polymer organic ligand, or a combination thereof, wherein R and R' are each independently a substituted or unsubstituted C1 to C100 aliphatic hydrocarbon group, a substituted or unsubstituted C6 to C50 aromatic hydrocarbon group, or a combination thereof, and optionally, one or more methylenes within the aliphatic hydrocarbon group are sulfonyl (-SO2-), carbonyl (CO), ether (-O-), sulfide (-S-), sulfoxide (-SO-), ester (-C(=O)O-), amide (-C(=O)NR-) (where R is hydrogen or a C1 to C10 alkyl group), or their Ink composition that can be replaced by a combination. Claim 4 An ink composition according to claim 1, wherein the first ligand comprises a monocarboxylic acid compound having a C10 to C40 substituted or unsubstituted hydrocarbyl group. Claim 5 An ink composition according to claim 1, wherein the second ligand comprises a functional group selected from an amine group, a thiol group, a carboxylic acid group, a phosphine group, or a combination thereof, and an organic compound having a residue connected to said functional group and represented by the following formula: In the above formula, L is a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C2 to C30 alkenylene group, a substituted or unsubstituted C3 to C30 cycloalkylene group, a substituted or unsubstituted C3 to C30 heterocycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a substituted or unsubstituted C3 to C30 heteroarylene group, sulfonyl (-SO2-), carbonyl (CO), ether (-O-), sulfide (-S-), sulfoxide (-SO-), ester (-C(=O)O-), amide (-C(=O)NR-) (where R is hydrogen or a C1 to C10 alkyl group), or a combination thereof, A is hydrogen, -COOH, -NR3 (where R is each independently hydrogen or a C1 to C10 alkyl group), or a combination thereof, and * is a functional group It is the connecting part. Claim 6 In claim 1, the liquid monomer comprises a carbon-carbon double bond and has a vapor pressure of 10 -4 Ink composition comprising a compound with a value of mmHg or less. Claim 7 An ink composition according to claim 1, wherein the organic solvent comprises a C3 to C40 substituted or unsubstituted aliphatic hydrocarbon solvent, a C6 to 40 substituted or unsubstituted aromatic hydrocarbon solvent, a C3 to C40 substituted or unsubstituted alicyclic hydrocarbon solvent, an alkylene glycol alkyl ether acetate solvent, an alkylacetamide solvent, or a combination thereof. Claim 8 An ink composition according to claim 1, wherein the liquid monomer comprises a monoacrylate compound, a diacrylate compound, a triacrylate compound, a tetraacrylate compound, a pentaacrylate compound, or a hexaacrylate compound or a combination thereof, and the organic solvent comprises propylene glycol monomethyl ether acetate, dimethylacetamide, cyclohexyl acetate, or a combination thereof. Claim 9 In claim 1, the ink composition has a viscosity of 40 cPs or less and a vapor pressure of 10 -3 Ink composition with a g / mmHg or less. Claim 10 delete Claim 11 In claim 1, the ink composition is an ink composition having a residual film rate of 90% or more after 30 minutes in film form. Claim 12 In claim 1, the ink composition is configured such that the relative EQE with respect to the initial external quantum efficiency (EQE) is 104% or less during irradiation with excitation light of a wavelength of 450 nm at a temperature of 60°C for 100 hours in a solid state after polymerization. Claim 13 A method for preparing an ink composition of claim 1, comprising the steps of: preparing a first solution comprising the first quantum dot and the organic solvent; preparing a second solution comprising the second quantum dot and the liquid monomer; and mixing the first solution and the second solution to maintain a colloidal dispersion state. Claim 14 In paragraph 13, the first solution and the second solution satisfy one of the following conditions: at least one of the first solution and the second solution does not exhibit both acid value and amine value; if the first solution exhibits either acid value or amine value, the second solution exhibits either acid value or amine value; if the first solution is amphoteric, exhibiting both acid value and amine value, the second solution is also amphoteric; or if one of the first solution and the second solution is amphoteric and the other exhibits acid value or amine value, in the amphoteric solution, the difference between the acid value and the amine value may be less than 5 mg KOH / g, or both the acid value and the amine value may be 35 mg KOH / g or more. Claim 15 An ink composition comprising a liquid vehicle comprising an organic solvent and a liquid monomer; and a plurality of quantum dots dispersed within the liquid vehicle and optionally metal oxide microparticles, wherein the content of the organic solvent in the ink composition is 20% by weight or less based on the total weight of the composition, and the ink composition is configured such that the relative EQE relative to the initial external quantum efficiency (EQE) is 104% or less during 100 hours of irradiation with excitation light of a wavelength of 450 nm at a temperature of 60°C in a solid state after polymerization, and the ink composition has both an acid value and an amine value, wherein both the acid value and the amine value are 35 mg KOH / g or more, or the difference between the acid value and the amine value is 5 mg KOH / g or less. Claim 16 In claim 15, the ink composition is configured to emit a first light, and the maximum emission peak of the first light has a full width at half maximum of 45 nm or less. Claim 17 In claim 15, the ink composition wherein the content of the organic solvent in the ink composition is 1 weight% or more and 10 weight% or less. Claim 18 A quantum dot complex comprising a matrix and a plurality of quantum dots dispersed within the matrix, wherein the plurality of quantum dots comprises a first quantum dot comprising a first ligand and a second quantum dot comprising a second ligand different from the first ligand, wherein the quantum dot complex emits light of a predetermined wavelength, and the quantum dot complex is configured such that the relative EQE relative to the initial external quantum efficiency (EQE) is 104% or less during irradiation with excitation light of a wavelength of 450 nm at a temperature of 60°C for 100 hours, and wherein the matrix has both an acid value and an amine value, and the acid value and the amine value are both 35 mg KOH / g or greater, or the difference between the acid value and the amine value is 5 mg KOH / g or less. Claim 19 delete Claim 20 A color conversion panel comprising a color conversion layer including a color conversion zone and a partition defining each zone of the color conversion layer according to selection, wherein the color conversion zone includes a first zone configured to emit a first light, and the first zone includes a quantum dot complex of claim 18. Claim 21 In claim 20, the color conversion zone further comprises a second zone configured to emit a second light different from the first light, and the second zone comprises a color conversion panel including the quantum dot complex. Claim 22 A display panel comprising a light-emitting panel, a color-converting panel of claim 20, and a light-transmitting layer located between the light-emitting panel and the color-converting panel.

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