Quantum dot composition, cured film, and display device

Abstract

Provided are a quantum dot composition, a cured film, and a display device. The quantum dot composition comprises I-III-VI-based quantum dots, wherein the I-III-VI-based quantum dots have two or more types of ligands, and the ligands include: a first ligand that is a reaction product between an aminothiol-based compound and a (meth) acrylate-based compound; and a second ligand that is a metal halide-based compound.

Description

Quantum dot composition, cured film and display device

[0001] The present invention relates to a quantum dot composition, a cured film, and a display device.

[0002] A quantum dot composition comprising quantum dots (QDs) is required to exhibit good patternability, prevent degradation of quantum dot light efficiency during thermal processes (exposure-development-washing-deposition) and additional thermal processes, and increase productivity. A cured film formed from the composition may experience a decrease in the external quantum efficiency and light conversion retention of the quantum dots during subsequent thermal processes.

[0003] As quantum dots, Cd series quantum dots are toxic, so InP series quantum dots are used. However, InP series quantum dots have a low extinction coefficient, so their content must be high to provide the desired amount of light when applied to displays, and the thickness of the single film must be increased when applied to display panels.

[0004] Development of Ag-In-Ga-S (AIGS) quantum dots, a 4-component quantum dot, is in full swing. The high absorbance of AIGS quantum dots allows for significantly reduced dosage in quantum dot compositions and reduced film thickness. However, AIGS quantum dots also require passivation to improve stability, including heat and light resistance, as well as optical properties and efficiency.

[0005] The present invention provides a quantum dot composition having excellent quantum dot dispersibility among photocurable monomers and having a high external quantum efficiency (EQE) and high maintenance rate of external quantum efficiency by minimizing the decrease in quantum efficiency of the quantum dot even after a subsequent process after photocuring.

[0006] According to one embodiment, a quantum dot composition is provided.

[0007] 1. The quantum dot composition includes a I-III-VI quantum dot, and the I-III-VI quantum dot has two or more ligands, wherein the ligands include a first ligand that is a reaction product between an aminothiol compound and a (meth)acrylate compound; and a second ligand that is a metal halide compound.

[0008] In 2.1, the aminothiol compound may include one or more compounds represented by the following chemical formula 1:

[0009] [Chemical Formula 1]

[0010]

[0011] (In the above chemical formula 1,

[0012] L 1 is a substituted or unsubstituted C1 to C10 alkylene group, or a substituted or unsubstituted C1 to C5 alkylene glycol group).

[0013] 3. In 1-2, the (meth)acrylate compound may include at least one of a monofunctional (meth)acrylate and a polyfunctional (meth)acrylate.

[0014] 4. In 1-3, the reaction product may include at least one reaction product of a thiol-ene reaction or a hydroamination reaction between the aminothiol compound and the (meth)acrylate.

[0015] 5. In 1-4, the first ligand may be included in an amount of 50 wt% or more of the total ligands of the I-III-VI quantum dot.

[0016] 6. In 1-5, the metal halide compound may include at least one of the following chemical formulas 6-1 and 6-2:

[0017] [Chemical Formula 6-1]

[0018] MX2

[0019] [Chemical Formula 6-2]

[0020] MX3

[0021] (In the above chemical formulas 6-1 and 6-2,

[0022] M is Ga or Zn,

[0023] X is a halide, F, Cl, Br, or I)

[0024] 7. In 6, the metal halide compound may include at least one of GaCl3 and ZnCl2.

[0025] 8. In 1-7, the second ligand may be included in an amount of 20 wt% or less of the total ligands of the I-III-VI quantum dot.

[0026] 9. In 1-8, the I-III-VI quantum dot may further include an amine compound as a third ligand.

[0027] 10. In 9, the amine compound may include at least one of the compounds of the following chemical formula 7:

[0028] [Chemical Formula 7]

[0029]

[0030] (In the above chemical formula 7,

[0031] L 71 , L 72 are each independently a substituted or unsubstituted C1 to C10 alkyl group.

[0032] x is between 1 and 100,

[0033] y is between 0 and 100).

[0034] 11. In 9-10, the sum of the first ligand, the second ligand, and the third ligand may be comprised at least 95 wt% of the total ligands of the I-III-VI quantum dot.

[0035] 12. In 1-11, the I-III-VI quantum dot may include a quantum dot core composed of group 11, group 13, and group 16.

[0036] 13. In 1-12, the quantum dot core may include Ag, In, Ga, and S.

[0037] 14. In 1-13, the composition may further include at least one of a photocurable monomer having an unsaturated bond, an initiator, a light scattering agent, and a polymerization inhibitor.

[0038] According to another embodiment, a cured film is provided.

[0039] The above cured film includes a cured product of the quantum dot composition.

[0040] In another embodiment, a display device is provided.

[0041] The above display device includes the above cured film.

[0042] A quantum dot composition with high uniformity of light efficiency was provided due to excellent dispersibility of quantum dots among photocurable monomers.

[0043] A quantum dot composition is provided that minimizes the decrease in quantum efficiency of quantum dots even after undergoing a subsequent process after photocuring, thereby increasing the external quantum efficiency and the maintenance rate of the external quantum efficiency of quantum dots, thereby enhancing the reliability of a display device.

[0044] Figure 1 is a conceptual diagram of a display device according to an embodiment.

[0045] Hereinafter, embodiments of the present application will be described in more detail with reference to the attached drawings. However, the technology disclosed in the present application is not limited to the embodiments described herein and may be embodied in other forms. However, the embodiments introduced herein are provided so that the disclosed content can be thorough and complete and so that the spirit of the present application can be sufficiently conveyed to those skilled in the art. In order to clearly express the components of each device in the drawings, the sizes of the components, such as width and thickness, are somewhat enlarged. However, the sizes of the components, such as width and thickness, in the present invention do not limit the scope of the present invention. The same reference numerals in multiple drawings indicate substantially the same components.

[0046] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0047] In this specification, "upper" and "lower" are defined based on the drawing, and depending on the perspective, "upper" may be changed to "lower" and "lower" may be changed to "upper", and reference to "on" or "on" may include not only directly on but also cases where another structure is interposed in between. On the other hand, reference to "directly on" or "directly above" or "directly formed" indicates cases where there is no intervening other structure such as an intermediate body.

[0048] Unless otherwise specified herein, "alkyl group" means a C1 to C20 alkyl group, "alkenyl group" means a C2 to C20 alkenyl group, "cycloalkenyl group" means a C3 to C20 cycloalkenyl group, "heterocycloalkenyl group" means a C3 to C20 heterocycloalkenyl group, "aryl group" means a C6 to C20 aryl group, "arylalkyl group" means a C6 to C20 arylalkyl group, "alkylene group" means a C1 to C20 alkylene group, "arylene group" means a C6 to C20 arylene group, "alkylarylene group" means a C6 to C20 alkylarylene group, "heteroarylene group" means a C3 to C20 heteroarylene group, and "alkoxylene group" means a C1 to C20 It refers to an alkoxylene group.

[0049] Unless otherwise specified herein, "substitution" means that at least one hydrogen atom is substituted with a halogen atom (F, Cl, Br, I), a hydroxy group, a C1 to C20 alkoxy group, a nitro group, a cyano group, an amine group, an imino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamyl group, a thiol group, an ester group, an ether group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C6 to C20 aryl group, a C7 to C20 arylalkyl group, a C3 to C20 cycloalkyl group, a C3 to C20 cycloalkenyl group, a C3 to C20 cycloalkynyl group, a C2 to C20 heterocycloalkyl group, a C2 to C20 It means substituted with a heterocycloalkenyl group, a C2 to C20 heterocycloalkynyl group, a C3 to C20 heteroaryl group, or a combination thereof.

[0050] Additionally, unless otherwise specified herein, “hetero” means that the chemical formula contains at least one heteroatom of at least one of N, O, S, and P.

[0051] Additionally, unless otherwise specified herein, “(meth)acrylate” means both “acrylate” and “methacrylate”, and “(meth)acrylic acid” means both “acrylic acid” and “methacrylic acid”.

[0052] Unless otherwise specified herein, “combination” means mixing or copolymerization.

[0053] Unless otherwise defined in the chemical formulas herein, if a chemical bond is not drawn at a position where a chemical bond should be drawn, it means that a hydrogen atom is bonded at that position.

[0054] When describing a numerical range in this specification, “X to Y” means X or more and Y or less (X≤ and ≤Y).

[0055] According to one embodiment, the quantum dot composition includes I-III-VI series quantum dots. Since the I-III-VI series quantum dots have a high extinction coefficient on their own, the content of quantum dots in the composition can be significantly reduced, and the thickness of the single film within the panel can be reduced, thereby increasing the degree of freedom in panel design.

[0056] The above-mentioned I-III-VI quantum dots generally have oleyl amine as a ligand in a pristine state. In order to produce the quantum dot composition in a solvent-free form, it is necessary to replace the oleyl amine with a different ligand of a different type.

[0057] According to one embodiment, the quantum dot composition comprises a I-III-VI quantum dot, wherein the I-III-VI quantum dot has two or more ligands, wherein the ligands include a first ligand that is a reaction product between an aminothiol-based compound and a (meth)acrylate-based compound; and a second ligand that is a metal halide-based compound.

[0058] The above quantum dot has a reaction product between an aminothiol compound and a (meth)acrylate compound as the first ligand through ligand substitution. Specifically, an alkyl amine in a pristine state, such as oleylamine, is substituted with the reaction product.

[0059] The above reaction product can increase the dispersibility of quantum dots among photocurable monomers, minimize the decrease in quantum efficiency of quantum dots even after photocuring and subsequent processes, thereby increasing the external quantum efficiency (EQE) and the maintenance rate of external quantum efficiency of quantum dots.

[0060] The quantum dot has a metal halide compound as a second ligand through capping. The metal halide compound can improve the optical properties of the quantum dot composition. In particular, the second ligand can minimize the decrease in quantum efficiency of the quantum dot when the I-III-VI quantum dot has the first ligand, thereby facilitating the increase in the external quantum efficiency and the maintenance rate of the external quantum efficiency of the quantum dot.

[0061] Although the above quantum dot composition is a solvent-free composition, the dispersibility of the I-III-VI quantum dots is excellent, so that agglomeration of the I-III-VI quantum dots is prevented, and a cured film in which the I-III-VI quantum dots are uniformly distributed can be manufactured.

[0062] The above quantum dot composition has a high external quantum efficiency of the quantum dot when subjected to a subsequent process after photocuring by exposure, and the external quantum efficiency of the quantum dot can be maintained without decreasing.

[0063] Here, 'photocuring by exposure' means light irradiation at a wavelength of 190 nm to 450 nm, for example 200 nm to 500 nm.

[0064] Here, the 'follow-up process' may include a heat treatment in a nitrogen atmosphere or air at a temperature of 80°C or higher, for example, 180 to 200°C, for 1 to 60 minutes. In the above-described follow-up process, the heat treatment may be performed one or more times, for example, two or more times.

[0065] In this regard, a specimen manufactured with the quantum dot composition may have an external quantum efficiency of 20% or more, for example, 20 to 40%, after being cured (POB) in a nitrogen atmosphere at 180°C for 30 minutes.

[0066] The specimen manufactured with the above quantum dot composition was coated with the above quantum dot composition to a thickness of 10 μm and exposed to 5000 mJ / cm at a wavelength of 395 nm under a nitrogen atmosphere. 2 It can be manufactured by exposure to light.

[0067] Hereinafter, each component of the quantum dot composition will be described in detail.

[0068] quantum dots

[0069] The quantum dot is a I-III-VI quantum dot, and the I-III-VI quantum dot includes two or more ligands, wherein the ligands include a first ligand that is a reaction product between an aminothiol-based compound and a (meth)acrylate-based compound; and a second ligand that is a metal halide-based compound.

[0070] The above aminothiol compound is a compound having an amine group and a thiol group and can react with the (meth)acrylate compound. For example, the aminothiol compound may include one or more compounds represented by the following chemical formula 1:

[0071] [Chemical Formula 1]

[0072]

[0073] (In the above chemical formula 1,

[0074] L 1is a substituted or unsubstituted C1 to C10 alkylene group, or a substituted or unsubstituted C1 to C5 alkylene glycol group).

[0075] For example, the aminothiol compound may include at least one of 2-aminoethanethiol and amine-PEG-thiol. Here, amine-PEG-thiol is a compound in which PEG (polyethylene glycol) has an NH2 group at one terminal and an SH group at the other terminal.

[0076] The above (meth)acrylate compound may include at least one of a monofunctional (meth)acrylate and a polyfunctional (meth)acrylate.

[0077] The above monofunctional (meth)acrylate has one (meth)acrylate group, and thus can undergo the above reaction with the aminothiol-based compound described above. The above monofunctional (meth)acrylate provides only one reaction site for the aminothiol-based compound, compared to the polyfunctional (meth)acrylate described below, thereby preventing the reaction from proceeding excessively, thereby lowering the degree of agglomeration of quantum dots, and thereby enabling the quantum dots to be uniformly dispersed.

[0078] The above monofunctional (meth)acrylate may include a (meth)acrylate having an alkylene oxide group (alkylene glycol group), a cycloalkyl group, an aryl group, or a combination thereof in the ester moiety.

[0079] In one specific example, the monofunctional (meth)acrylate may include at least one of the following chemical formulae 2 to 4:

[0080] [Chemical Formula 2]

[0081]

[0082] (In the above chemical formula 2,

[0083] R 1 is a hydrogen or methyl group,

[0084] L 21is a substituted or unsubstituted C1 to C10 alkylene group,

[0085] L 22 is a substituted or unsubstituted C1 to C10 alkyl group

[0086] n is an integer from 1 to 10).

[0087] [Chemical Formula 3]

[0088]

[0089] (In the above chemical formula 3,

[0090] R 1 is a hydrogen or methyl group,

[0091] L 31 is a single bond, a substituted or unsubstituted C1 to C10 alkylene group or a substituted or unsubstituted C6 to C10 arylene group,

[0092] L 32 is a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms).

[0093] [Chemical Formula 4]

[0094]

[0095] (In the above chemical formula 4,

[0096] R 1 is a hydrogen or methyl group,

[0097] L 41 is a substituted or unsubstituted C1 to C10 alkylene group or a substituted or unsubstituted C6 to C10 arylene group,

[0098] L 42 is a substituted or unsubstituted C6 to C10 aryl group or a substituted or unsubstituted C6 to C10 aryloxy group.

[0099] m is an integer from 1 to 10).

[0100] For example, the monofunctional (meth)acrylate may include at least one of isobornyl (meth)acrylate, mono(ethylene glycol) (meth)acrylate, poly(ethylene glycol) (meth)acrylate, phenoxy mono(ethylene glycol) (meth)acrylate, and phenoxy poly(ethylene glycol) (meth)acrylate.

[0101] The reaction between the above aminothiol compound and the (meth)acrylate may include at least one of a thiol-ene reaction and a hydroamination reaction.

[0102] In one specific example, the reaction between the monofunctional (meth)acrylate of the above-described chemical formula 3 and the aminothiol compound can be carried out, for example, by the following reaction scheme 1 (thiol-ene reaction) or reaction scheme 2 (hydroamination):

[0103] [Reaction Formula 1]

[0104]

[0105] [Reaction Formula 2]

[0106]

[0107] (In the above reaction formulas 1 and 2

[0108] L 1 , L 31 , L 32 , R 1 , R 2 are the same as described in the chemical formula 1 and chemical formula 3, respectively).

[0109] The above multifunctional (meth)acrylate can undergo the above reaction with the above-described aminothiol compound by having two or more (meth)acrylate groups.

[0110] The above multifunctional (meth)acrylate may include at least one of the following chemical formula 5:

[0111] [Chemical Formula 5]

[0112]

[0113] (In the above chemical formula 5,

[0114] R 1 and R 2 are each independently a hydrogen or methyl group,

[0115] L 51 , L 53 are each independently a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 monoalkylene oxide group, a substituted or unsubstituted C1 to C10 polyalkylene oxide group, or a combination thereof,

[0116] L 52 is a substituted or unsubstituted C1 to C10 alkylene group, an ether group (*-O-*) or a combination thereof.

[0117] For example, the multifunctional (meth)acrylate may include at least one of the following chemical formulae 5-1 and 5-2, but is not necessarily limited thereto.

[0118] [Chemical Formula 5-1]

[0119]

[0120] [Chemical Formula 5-2]

[0121]

[0122] (In the above chemical formulas 5-1 and 5-2, R 1 , R 2 are each the same as defined in the above chemical formula 5)

[0123] For example, the above-mentioned multifunctional (meth)acrylate, in addition to the compounds represented by the above-mentioned chemical formulas 5-1 and 5-2, includes ethylene glycol diacrylate, triethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, dipentaerythritol diacrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, pentaerythritol hexaacrylate, bisphenol A diacrylate, trimethylolpropane triacrylate, novolac epoxy acrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanedioldimethacrylate or a combination thereof may be further included.

[0124] In one specific embodiment, the reaction product may include one or more of the following formulae A to H:

[0125] [Chemical Formula A]

[0126]

[0127] [Chemical Formula B]

[0128]

[0129] [Chemical Formula C]

[0130]

[0131] [Chemical Formula D]

[0132]

[0133] [Chemical Formula E]

[0134]

[0135] [Chemical formula F

[0136]

[0137] [Chemical formula G]

[0138]

[0139] [Chemical formula H]

[0140]

[0141] (In the above chemical formulas A to H,

[0142] L 1 , L 21 , L 22 , L 31 , L 32 , L 41 , L 42 , L 51 , L 52 , L 53 , R 1 , R 2 , n and m are the same as defined in the above chemical formulas 2 to 5).

[0143] The above reaction product can be introduced into the quantum dot by the method described below:

[0144] According to one embodiment, by mixing a pristine I-III-VI quantum dot with an aminothiol compound and a (meth)acrylate compound and then reacting them, the reaction product can be substituted with the first ligand in the I-III-VI quantum dot.

[0145] According to another embodiment, after the aminothiol compound and the monofunctional (meth)acrylate are reacted, the pristine I-III-VI quantum dot is introduced, so that the reaction product can be substituted with the first ligand in the pristine I-III-VI quantum dot.

[0146] According to another embodiment, the pristine I-III-VI quantum dots are reacted with an aminothiol compound to ligand-substitute the oleyl amine of the pristine I-III-VI quantum dots with the aminothiol compound, and a monofunctional (meth)acrylate is introduced, thereby allowing the above reaction between the ligand-substituted aminothiol compound and the monofunctional (meth)acrylate to be performed.

[0147] The above thiol-ene reaction and hydroamination reaction can each be performed by methods known to those skilled in the art. Catalysts and the like may be used to increase the reaction rate or efficiency in the above reaction.

[0148] According to one embodiment, the first ligand may be included in an amount of 50 wt% or more, for example, 80 wt% or more, for example, 85 to 95 wt%, of the total ligand of the I-III-VI quantum dot. Within this range, it may be easy to realize the effects of the I-III-VI quantum dot described above.

[0149] The above I-III-VI quantum dots contain a metal halide compound as a second ligand.

[0150] The above metal halide compound can enhance the optical properties of the quantum dots by further passivating the I-III-VI quantum dots by providing at least one metal, particularly Ga or Zn, among the I-III-VI quantum dots.

[0151] The above metal halide compound may include at least one of the following chemical formulas 6-1 and 6-2:

[0152] [Chemical Formula 6-1]

[0153] MX2

[0154] [Chemical Formula 6-2]

[0155] MX3

[0156] (In the above chemical formulas 6-1 and 6-2,

[0157] M is Ga or Zn,

[0158] X is a halide, F, Cl, Br, or I)

[0159] Specifically, the metal halide compound may include at least one of GaCl3 and ZnCl2.

[0160] The above metal halide compound may be introduced as a ligand in a process of purifying or precipitating the pristine I-III-VI quantum dot after oleylamine is ligand-substituted with the first ligand, or the first ligand and the third ligand below, using a solvent containing the metal halide compound. The solvent may include, but is not limited to, one or more of acetone and cyclohexane.

[0161] According to one embodiment, the second ligand may be included in an amount of 50 wt% or less, for example, 20 wt% or less, for example, 5 to 15 wt%, of the total ligand of the I-III-VI quantum dot. Within this range, it may be easy to realize the effects of the I-III-VI quantum dot described above.

[0162] The above I-III-VI quantum dots may further include an amine compound as a third ligand. Among the pristine I-III-VI quantum dots, oleylamine may be further ligand-substituted with the amine compound:

[0163] The above amine compound can further provide a passivation effect by being included as a third ligand in the I-III-VI quantum dot.

[0164] The above amine compound may include at least one compound of the chemical formula 7 below.

[0165] [Chemical Formula 7]

[0166]

[0167] (In the above chemical formula 7,

[0168] L 71 , L 72 are each independently a substituted or unsubstituted C1 to C10 alkyl group.

[0169] x is between 1 and 100,

[0170] y is between 0 and 100).

[0171] According to one embodiment, the third ligand may be included in the I-III-VI quantum dot in an amount of 0 to 50 wt%, for example, 5 to 45 wt%, for example, 20 to 30 wt%.

[0172] According to one embodiment, the total sum of the first ligand and the second ligand may be comprised at least 95 wt%, for example, 95 to 100 wt%, or 100 wt%, of the total ligands of the I-III-VI quantum dot. Within this range, the above-described effects may be easily achieved.

[0173] According to another embodiment, the sum total of the first ligand, the second ligand, and the third ligand may be comprised at least 95 wt%, for example, 95 to 100 wt%, or 100 wt%, of the total ligands of the I-III-VI quantum dot. Within this range, the above-described effects may be easily achieved.

[0174] The above I-III-VI quantum dots include a quantum dot core composed of groups 11-13-16.

[0175] The group 11 element constituting the quantum dot core may be at least one of Cu, Ag, and Au, the group 13 element may be at least one of In, Ga, and Al, and the group 16 element may be at least one of S, Se, and Te.

[0176] The quantum dot core may contain Ag, In, Ga, and S. In this case, it may be referred to as an AIGS core.

[0177] The group 11 element: group 13 element that constitutes the quantum dot core can be in a ratio of 1:1 to 1:10. Within this ratio, the quantum dot core can emit visible light ranging from blue to yellow-green. In addition, the group 13 element that constitutes the quantum dot core is In. 1-x Ga xIt can be composed of, and 0.2≤x≤0.9 can be made. In this way, adjusting the composition ratio between the group 11 elements and the group 13 elements is performed to adjust the wavelength characteristics, but while adjusting the composition ratio between the group 11 elements and the group 13 elements, the composition ratio between the group 13 elements, In and Ga, can be adjusted. In this case, the emission center wavelength of the quantum dot core can be 520-540 nm. This center wavelength corresponds to green emission, and can be, for example, 530 nm. A quantum dot including such a quantum dot core can be used as a display material.

[0178] The quantum efficiency of the above quantum dot core may be greater than 20%. This means that the quantum efficiency is at least 20%.

[0179] The full width at half maximum of the above quantum dot core may be 40 nm or less. In order to apply the I-III-Ⅵ system quantum dots as display materials, they must have a narrow full width at half maximum of 50 nm or less. Since the quantum dot core of the quantum dot according to the present invention may have a full width at half maximum of 40 nm or less, it can be applied as a display material.

[0180] The size of the quantum dot core can range from 3 to 6 nm. For example, the average size can be 5.5 nm. A quantum dot core size outside this range is undesirable in terms of quantum efficiency. The manufacturing method according to the present invention is suitable for synthesizing quantum dot cores of this size.

[0181] Under 450 nm blue light excitation, the quantum dot cores are 1×10 5 M -1 cm -1 It may exhibit the above molar absorption coefficient. This molar absorption coefficient is superior to that of InP quantum dots. In other words, the quantum dot core may be a green quantum dot with high blue absorbance. Thus, according to the present invention, it is possible to secure a quantum dot core, particularly an AIGS core, that exhibits a significantly low level of defect-state luminescence.

[0182] The I-III-VI quantum dots having two or more types of ligands can be prepared by replacing the first ligand and the second ligand described above in the form having the initial ligand formed on the surface of the quantum dot core (pristine quantum dot form).

[0183] The initial ligand may be a thiol series such as 1-dodecanethiol (DDT). In addition to DDT, it may be various alkyl thiol series such as 1-octanethiol, hexadecanethiol, decanethiol, etc. In addition, the initial ligand may be derived from a solvent used in the manufacturing method. Here, the solvent may be one or more of 1-octadecene (ODE), oleylamine (OLA), oleic acid (OA), dodecylamine, trioctylamine (TOA), and trioctylphosphine (TOP).

[0184] When the quantum dot composition according to one embodiment is a solvent-free quantum dot composition, the quantum dots may be included in an amount of 5 to 60 wt%, for example, 10 to 60 wt%, for example, 20 to 60 wt%, for example, 30 to 50 wt%. When the quantum dots are included within the above range, high light retention and light efficiency can be achieved even after curing.

[0185] The above quantum dot composition may further include a photocurable monomer having an unsaturated bond.

[0186] Photocurable monomer with unsaturated bonds

[0187] The quantum dot composition comprises a photocurable monomer containing an unsaturated bond. For example, the photocurable monomer may be a photocurable monomer having a carbon-carbon double bond at the terminal.

[0188] The photocurable monomer may be included in an amount of 30 to 70 wt%, for example, 40 to 70 wt%, for example, 45 to 65 wt%, for example, 45 to 60 wt%, based on the total amount of the quantum dot composition (e.g., based on solid content). Within this range, a composition having a viscosity that enables inkjet jetting of the composition, particularly a solvent-free quantum dot composition, can be produced, and furthermore, the quantum dots in the produced composition, particularly the solvent-free quantum dot composition, can have excellent dispersibility, so that the optical properties can also be improved.

[0189] The photocurable monomer may have a molecular weight of 150 g / mol to 1,000 g / mol. Within this range, the composition may be advantageous for ink-jetting because the viscosity of the composition may not be increased without impairing the optical properties of the quantum dots.

[0190] The photocurable monomer may be represented by the chemical formula 5, but is not necessarily limited thereto:

[0191] For example, the photocurable monomer may include at least one of the chemical formulas 5-1 and 5-2, but is not necessarily limited thereto.

[0192] For example, the photocurable monomer, in addition to the compounds represented by the chemical formulas 5-1 and 5-2, may be selected from the group consisting of ethylene glycol diacrylate, triethylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, dipentaerythritol diacrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, pentaerythritol hexaacrylate, bisphenol A diacrylate, trimethylolpropane triacrylate, novolac epoxy acrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanedioldimethacrylate or a combination thereof may be further included.

[0193] Initiator

[0194] The curable composition according to one embodiment may further comprise an initiator, for example, a photopolymerization initiator, a thermal polymerization initiator, or a combination thereof.

[0195] The above photopolymerization initiator is an initiator capable of initiating a polymerization reaction by light, and examples thereof include, but are not limited to, acetophenone-based compounds, benzophenone-based compounds, thioxanthone-based compounds, benzoin-based compounds, triazine-based compounds, oxime-based compounds, and aminoketone-based compounds.

[0196] Examples of the above acetophenone compounds include 2,2'-diethoxy acetophenone, 2,2'-dibutoxy acetophenone, 2-hydroxy-2-methylpropiophenone, pt-butyltrichloro acetophenone, pt-butyldichloro acetophenone, 4-chloro acetophenone, 2,2'-dichloro-4-phenoxy acetophenone, 2-methyl-1-(4-(methylthio)phenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, etc.

[0197] Examples of the above benzophenone compounds include benzophenone, benzoyl benzoate, methyl benzoyl benzoate, 4-phenyl benzophenone, hydroxybenzophenone, acrylated benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, 4,4'-dimethylaminobenzophenone, 4,4'-dichlorobenzophenone, 3,3'-dimethyl-2-methoxybenzophenone, etc.

[0198] Examples of the above thioxanthone compounds include thioxanthone, 2-methylthioxanthone, isopropyl thioxanthone, 2,4-diethyl thioxanthone, 2,4-diisopropyl thioxanthone, 2-chlorothioxanthone, etc.

[0199] Examples of the above benzoin compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyldimethyl ketal, etc.

[0200] Examples of the above triazine compounds include 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine, 2-biphenyl-4,6-bis(trichloromethyl)-s-triazine, bis(trichloromethyl)-6-styryl-s-triazine, Examples thereof include 2-(naphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-4-bis(trichloromethyl)-6-piperonyl-s-triazine, and 2-4-bis(trichloromethyl)-6-(4-methoxystyryl)-s-triazine.

[0201] Examples of the above oxime compounds include O-acyloxime compounds, 2-(O-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione, 1-(O-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone, O-ethoxycarbonyl-α-oxyamino-1-phenylpropan-1-one, etc. Specific examples of the O-acyloxime compounds include 1,2-octanedione, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, 1-(4-phenylsulfanylphenyl)-butane-1,2-dione-2-oxime-O-benzoate, 1-(4-phenylsulfanylphenyl)-octane-1,2-dione-2-oxime-O-benzoate, 1-(4-phenylsulfanylphenyl)-octane-1-oneoxime-O-acetate, and 1-(4-phenylsulfanylphenyl)-butan-1-oneoxime-O-acetate.

[0202] Examples of the above aminoketone compounds include 2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1.

[0203] In addition to the above compound, the photopolymerization initiator may also include a carbazole compound, a diketone compound, a sulfonium borate compound, a diazo compound, an imidazole compound, a biimidazole compound, etc.

[0204] The above photopolymerization initiator may also be used together with a photosensitizer that causes a chemical reaction by absorbing light, becoming excited, and then transferring the energy.

[0205] Examples of the above photosensitizer include tetraethylene glycol bis-3-mercapto propionate, pentaerythritol tetrakis-3-mercapto propionate, dipentaerythritol tetrakis-3-mercapto propionate, and the like.

[0206] Examples of the above thermal polymerization initiator include peroxides, specifically benzoyl peroxide, dibenzoyl peroxide, lauryl peroxide, dilauryl peroxide, di-tert-butyl peroxide, cyclohexane peroxide, methyl ethyl ketone peroxide, hydroperoxides (e.g., tert-butyl hydroperoxide, cumene hydroperoxide), dicyclohexyl peroxydicarbonate, 2,2-azo-bis(isobutyronitrile), t-butyl perbenzoate, etc., and 2,2'-azobis-2-methylpropionitrile, etc., but are not necessarily limited thereto, and any one widely known in the art can be used.

[0207] The photopolymerization initiator may be included in an amount of 0.1 to 5 wt%, for example, 1 to 4 wt%, based on the total amount of the quantum dot composition (e.g., based on solid content). When included within the above range, sufficient curing occurs upon exposure to light or thermal curing, thereby achieving excellent reliability, and preventing a decrease in transmittance due to unreacted initiator, thereby preventing a decrease in the optical properties of the quantum dot.

[0208] light scattering agent

[0209] A quantum dot composition according to one embodiment may further include a light scattering agent.

[0210] The above light scattering agent may include barium sulfate (BaSO4), calcium carbonate (CaCO3), titanium dioxide (TiO2), zirconia (ZrO2), or a combination thereof.

[0211] The light-scattering agent reflects light not absorbed by the aforementioned quantum dots and allows the reflected light to be reabsorbed by the quantum dots. In other words, the light-scattering agent can increase the amount of light absorbed by the quantum dots, thereby increasing the photoconversion efficiency of the quantum dot composition.

[0212] The above light scattering agent has an average particle diameter (D 50) may be 150 nm to 250 nm, and specifically, 180 nm to 230 nm. When the average particle diameter of the light diffusing agent is within the above range, it may have a better light diffusing effect and increase the light conversion efficiency.

[0213] The light-scattering agent may be included in an amount of 1 to 20 wt%, for example 2 to 15 wt%, for example 3 to 10 wt%, based on the total amount of the quantum dot composition (e.g., based on solid content). Within this range, an effect of improving the light conversion efficiency due to the use of the light-scattering agent can be expected, and quantum dot sedimentation problems may not occur.

[0214] additives

[0215] In order to improve the stability and dispersibility of the above quantum dots, the solvent-free quantum dot composition according to one embodiment may further include a polymerization inhibitor.

[0216] The polymerization inhibitor may include, but is not necessarily limited to, a hydroquinone-based compound, a catechol-based compound, or a combination thereof. According to one embodiment, since the solvent-free quantum dot composition further includes the hydroquinone-based compound, the catechol-based compound, or a combination thereof, crosslinking at room temperature can be prevented during exposure after printing (coating) the solvent-free quantum dot composition.

[0217] For example, the hydroquinone-based compound, catechol-based compound, or combinations thereof may include, but are not necessarily limited to, hydroquinone, methyl hydroquinone, methoxyhydroquinone, t-butyl hydroquinone, 2,5-di-t-butyl hydroquinone, 2,5-bis(1,1-dimethylbutyl) hydroquinone, 2,5-bis(1,1,3,3-tetramethylbutyl) hydroquinone, catechol, t-butyl catechol, 4-methoxyphenol, pyrogallol, 2,6-di-t-butyl-4-methylphenol, 2-naphthol, tris(N-hydroxy-N-nitrosophenylaminato-O,O')aluminium, or combinations thereof.

[0218] The above hydroquinone-based compound, catechol-based compound, or a combination thereof may be used in the form of a dispersion, and the polymerization inhibitor in the form of the dispersion may be included in an amount of 0.001 wt% to 3 wt%, for example, 0.1 wt% to 2 wt%, based on the total amount of the solvent-free quantum dot composition. When the polymerization inhibitor is included within the above range, the problem of aging at room temperature can be solved, while at the same time preventing a decrease in sensitivity and surface peeling.

[0219] The solvent in the above composition may be included in an amount of 2 parts by weight or less, for example, 0 to 2 parts by weight, per 100 parts by weight of the solid content of the above composition.

[0220] In addition, the quantum dot composition according to one embodiment may further include malonic acid; 3-amino-1,2-propanediol; a silane coupling agent; a leveling agent; a fluorinated surfactant; or a combination thereof to improve heat resistance and reliability.

[0221] For example, the quantum dot composition according to one embodiment may further include a silane coupling agent having a reactive substituent such as a vinyl group, a carboxyl group, a methacryloxy group, an isocyanate group, or an epoxy group to improve adhesion to a substrate, etc.

[0222] Examples of the above silane coupling agent include trimethoxysilyl benzoic acid, γ-methacryloxypropyl trimethoxysilane, vinyl triacetoxysilane, vinyl trimethoxysilane, γ-isocyanate propyl triethoxysilane, γ-glycidoxy propyl trimethoxysilane, β-epoxycyclohexyl)ethyl trimethoxysilane, etc., and these may be used alone or in combination of two or more.

[0223] The above silane coupling agent may be included in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the quantum dot composition. When the silane coupling agent is included within the above range, adhesion, storability, etc. are excellent.

[0224] In addition, the solvent-free quantum dot composition may further include a surfactant, such as a fluorinated surfactant, to improve coating properties and prevent defect formation, i.e., to improve leveling performance, if necessary. The fluorinated surfactant may have a low weight average molecular weight of 4,000 g / mol to 10,000 g / mol, specifically, a weight average molecular weight of 6,000 g / mol to 10,000 g / mol. In addition, the fluorinated surfactant may have a surface tension of 18 mN / m to 23 mN / m (measured in a 0.1% propylene glycol monomethyl ether acetate (PGMEA) solution). When the weight average molecular weight and surface tension of the above fluorinated surfactant are within the above range, the leveling performance can be further improved, the occurrence of stains can be prevented during high-speed coating, and since the occurrence of bubbles is small and the film defects are small, it provides excellent characteristics to slit coating, which is a high-speed coating method.

[0225] Additionally, the quantum dot composition according to one embodiment may use a silicone-based surfactant together with the aforementioned fluorine-based surfactant. Specific examples of the silicone-based surfactant include, but are not limited to, TSF400, TSF401, TSF410, and TSF4440 from Toshiba Silicone Co., Ltd.

[0226] The surfactant, including the fluorinated surfactant, may be included in an amount of 0.01 to 5 parts by weight, for example, 0.1 to 2 parts by weight, based on 100 parts by weight of the solvent-free quantum dot composition. When the surfactant is included within the above range, the phenomenon of foreign substances occurring in the sprayed composition is reduced.

[0227] In addition, the quantum dot composition according to one embodiment may further include a certain amount of other additives, such as antioxidants, within a range that does not impair physical properties.

[0228] Another aspect provides a cured film manufactured using the quantum dot composition and a display device including the cured film.

[0229] According to one embodiment, the cured film comprises a cured product of the quantum dot composition.

[0230] One of the methods for manufacturing the above-mentioned cured film includes a step (S1) of forming a pattern by applying the above-mentioned quantum dot composition onto a substrate using an inkjet jetting method; and a step (S2) of curing the pattern.

[0231] (S1) Pattern forming step

[0232] The above quantum dot composition is preferably applied to a substrate at a thickness of 0.5 to 20 μm using an inkjet jetting method. The inkjet jetting method can form a pattern by repeatedly spraying only a single color from each nozzle according to the required number of colors. To reduce the process, the pattern can also be formed by simultaneously spraying the required number of colors through each inkjet nozzle.

[0233] The above inkjet jetting method can use an inkjet printer having an inkjet head equipped with a piezo-type nozzle that applies pressure according to voltage.

[0234] More specifically, the quantum dot composition is ejected from a nozzle of an inkjet head onto a substrate. At this time, the ejection amount of the composition may be 1 to 80 pL / time, for example, 1 to 30 pL / time, or as another example, 1 to 20 pL / time.

[0235] The aperture of the inkjet head may be, but is not limited to, 5 to 100 μm, for example, 10 to 80 μm, to minimize clogging of the nozzle and improve ejection precision.

[0236] The ejection pressure of the inkjet head is 1000 to 100000s based on the shear speed. -1 It may be, but is not limited to,

[0237] The temperature at the time of discharge is not particularly limited, but may be 10 to 120°C, for example, 15 to 60°C, as another example, 15 to 40°C, or as another example, 20 to 35°C, from the viewpoint of suppressing crystallization of materials included in the ink composition.

[0238] (S2) Hardening stage

[0239] The pattern obtained above can be cured to obtain pixels. At this time, a photocuring process can be applied as a curing method. The photocuring process irradiates active rays such as UV rays having a wavelength of 190 nm to 450 nm, for example, 200 nm to 500 nm. Light sources used for irradiation include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, argon gas lasers, etc., and in some cases, X-rays, electron beams, etc. can also be used.

[0240] Another method of manufacturing the above-mentioned cured film is to manufacture the cured film using the above-mentioned quantum dot composition using lithography, and the manufacturing method is as follows.

[0241] (1) Application and film formation stage

[0242] The above-described quantum dot composition is applied to a substrate that has undergone a predetermined pretreatment using a spin or slit coating method, a roll coating method, a screen printing method, an applicator method, or the like to a desired thickness, for example, 2 μm to 10 μm, and then heated at a temperature of 70°C to 90°C for 1 to 10 minutes to remove the solvent, thereby forming a film.

[0243] (2) Exposure stage

[0244] In order to form a necessary pattern on the obtained film, a mask of a predetermined shape is interposed, and then an active ray such as UV light of 190 nm to 450 nm, for example, 200 nm to 500 nm, is irradiated. Light sources used for irradiation include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, argon gas lasers, etc., and in some cases, X-rays, electron beams, etc. can also be used.

[0245] The exposure dose varies depending on the type, mixing amount, and dry film thickness of each component of the quantum dot composition, but for example, when using a high-pressure mercury lamp, it is 500 mJ / cm 2　 Below (based on 365 nm sensor).

[0246] (3) Phenomenon stage

[0247] Following the above exposure step, an alkaline aqueous solution is used as a developer to dissolve and remove unnecessary portions, leaving only the exposed portions to form an image pattern. That is, when developing with an alkaline developer, the unexposed portions are dissolved, and an image color filter pattern is formed.

[0248] (4) Post-processing stage

[0249] The image pattern obtained by the above phenomenon can be cured by reheating or irradiating with active rays, etc., to obtain a pattern superior in terms of heat resistance, light resistance, adhesion, crack resistance, chemical resistance, high strength, storage stability, etc.

[0250] Another viewpoint is the display device, which includes the cured film.

[0251] According to one embodiment, the display device includes a color filter layer including the cured film. According to one embodiment, the display device may be a light-emitting element display device including an organic light-emitting display device.

[0252] Figure 1 is a cross-sectional view of a light-emitting display device according to an embodiment.

[0253] Referring to FIG. 1, a display device (11) according to one embodiment includes a first substrate (111), two or more first electrodes (112) formed on the first substrate (111), a pixel defining film (113) formed between adjacent first electrodes (112), and a light source (10) including an organic light-emitting layer (120) formed on each of the first electrodes (112) and emitting a first light, a second electrode layer (114) formed on the organic light-emitting layer (120), and a first planarization layer (115) formed on the second electrode layer (114), a sealing layer (119) formed on the first planarization layer (115), a second planarization layer (118) formed on the sealing layer (119), and a quantum dot (3, 3r, 3g) formed on the second planarization layer (118) and converting the first light into at least one of different second light and third light. It includes a color filter layer (130) and a second substrate (116) formed on the color filter layer (130).

[0254] In a display device (11) according to one embodiment, the organic light-emitting layer (120) can be defined as a first pixel area, a second pixel area, and a third pixel area, and each pixel area is spaced apart at a predetermined interval by a pixel definition film (113). In one embodiment, unit layers belonging to the first to third pixel areas of the organic light-emitting layer (120) are defined as first to third organic light-emitting layers (120a to 120c), respectively.

[0255] The color filter layer (130) is formed to cover the space between adjacent light-blocking members (117). The color filter layer (130) includes first to third color filters (130r, 130g, 130b) formed at positions that overlap the first to third pixel areas described above, respectively.

[0256] In one embodiment, the first color filter (130r) can emit a second light different from the first light, the second color filter (130g) can emit a third light different from the first light, and the third color filter (130b) can emit the first light. For example, the first light can be blue light, the second light can be red light, and the third light can be green light.

[0257] Although not shown in FIG. 1, the display device may further include a color conversion layer.

[0258]

[0259] Hereinafter, the structure and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, these are presented as preferred examples of the present invention and should not be construed as limiting the present invention in any way.

[0260] Comparative Example 1

[0261] To 5 g of AIGS quantum dot solution (solvent: heptane, Nanosys, AIGS quantum dots having oleyl amine as a ligand) was added 10 g of cyclohexyl acetate as a solvent, 0.6 g of M-1000, 0.13 g of 2-aminoethanethiol, and 0.4 g of HDDA (1,6-hexanediol diacrylate). A ligand substitution reaction was performed at 75°C under inert conditions for 10 hours, to form oleyl amine with the thiol-ene reaction product of 2-aminoethanethiol and HDDA; and a ligand substitution reaction with M-1000 (step 1).

[0262] Then, the mixture was cooled, acetone was added, and the mixture was stirred at room temperature for 30 minutes. The ligand-substituted AIGS quantum dots were precipitated using cyclohexane. After centrifugation, the clear filtrate was removed, and the wet cake was vacuum-dried for 24 hours (step 2).

[0263] The manufactured quantum dot powder was dispersed in a photocurable monomer, HDDA, and titanium dioxide as a light diffusing agent and TPO-L as a photopolymerization initiator were mixed to manufacture a quantum dot ink composition. The quantum dot ink composition contains 15 wt% of quantum dots, 80 wt% of HDDA, 4 wt% of light diffusing agent, and 0.1 wt% of photopolymerization initiator and is solvent-free (step 3).

[0264] Example 1

[0265] Quantum dot powder was prepared in the same manner as in Comparative Example 1, except that acetone containing dissolved GaCl3 was used instead of acetone after cooling in step 2 above. The prepared quantum dot powder has a thiol-ene reaction product of 2-aminoethanethiol and HDDA; M-1000; and GaCl3 as ligands.

[0266] A quantum dot composition was prepared using the manufactured quantum dot powder in the same manner as in step 3 of Comparative Example 1.

[0267] Example 2

[0268] Quantum dot powder was prepared in the same manner as in Comparative Example 1, except that acetone containing ZnCl2 dissolved therein was used instead of acetone after cooling in step 2 above. The prepared quantum dot powder has a thiol-ene reaction product of 2-aminoethanethiol and HDDA; M-1000; and ZnCl2 as ligands.

[0269] A quantum dot composition was prepared using the same method as step 3 in Comparative Example 1 using the manufactured quantum dot powder.

[0270] Example 3

[0271] Quantum dot powders manufactured by the same method as in Example 1 except that ETGA (tri(ethylene glycol) ethyl ether acrylate) was used instead of HDDA in Example 1, had a thiol-ene reaction product of 2-aminoethanethiol and ETGA; M-1000; and ZnCl2 as ligands.

[0272] A quantum dot composition was prepared using the same method as step 3 in Comparative Example 1 using the manufactured quantum dot powder.

[0273] The chemical formulas of 2-aminoethanethiol, M-1000, HDDA and ETGA used in the examples and comparative examples are as follows.

[0274] <2-Aminoethanethiol (2-AET)>

[0275]

[0276] <m-1000>

[0277]

[0278] (R is CH3)

[0279] <hdda>

[0280]

[0281] <etga>

[0282]

[0283] The following physical properties were evaluated using the quantum dot ink compositions manufactured in the examples and comparative examples.

[0284] (1) Absorbance (unit: %), EQE (external quantum efficiency, unit: %), λmax (unit: nm), FWHM (full width at half maximum) (unit: nm): Each quantum dot composition corresponding to the examples and comparative examples was applied to a bare glass with a thickness of 10 μm using a spin coater (Mikasa, opticoat MS-A150, 1050 rpm, 5 seconds), and exposed to light (wavelength 395 nm) at 5000 mJ / cm in a nitrogen atmosphere. 2 Exposure (EXP) was performed. Afterwards, the optical properties (absorption rate, optical properties) of a single film (2 cm x 2 cm) of the manufactured specimen were measured for a single extraction wavelength of 450 nm using an integrating hemisphere quantum efficiency meter (Otsuka, QE-2100).

[0285] (2) Absorbance (unit: %) and EQE (external quantum efficiency, unit: %): Each quantum dot composition corresponding to the examples and comparative examples was applied to a thickness of 10 μm on bare glass using a spin coater (Mikasa, opticoat MS-A150, 1050 rpm, 5 seconds), and exposed to 5000 mJ / cm2 in an exposure device (wavelength 395 nm) under a nitrogen atmosphere. 2 Exposure (EXP) was performed. Afterwards, EQE was measured for a single film (2 cm x 2 cm) of the manufactured specimen using an integral hemisphere quantum efficiency meter (Otsuka, QE-2100).

[0286] Afterwards, the above-mentioned short film is cured (POB) in a nitrogen atmosphere at 85°C for 30 minutes, and then cooled for 1 hour.

[0287] (1) Single-film optical properties (absorption rate, optical properties, wavelength, half-width) were measured using the same method.

[0288] The retention rate was calculated as the percentage of the EQE measured in the POB relative to the EQE measured after exposure. A higher retention rate indicates a lower rate of decrease in the optical efficiency of the cured film formed with the quantum dot ink composition.

[0289] (3) THK: THK (thickness, unit: ㎛) was measured using a profiler (KLA-Tencor, P-6).

[0290] Post-exposure POB AbsorbanceEQE AbsorbanceEQE RetentionλmaxFWHMTHK Comparative Example 187.326.387.225.396.2530.230.010.0 Example 186.228.986.127.996.5530.430.210.0 Example 286.827.986.827.598.4530.230.410.0 Example 386.929.686.828.596.3530.530.210.0

[0291] According to Table 1 above, it can be confirmed that the quantum dot composition containing the quantum dot powder of the example exhibits superior EQE compared to the comparative example.

[0292] The metal content of the quantum dot powders manufactured in the examples and comparative examples was analyzed using ICP-OES (inductively coupled plasma-optical spectroscopy), and the Cl content was analyzed using IC (ion chromatography). The results are shown in Table 2 below.

[0293] ICP-OES(%)IC(%)InSAgGaClComparative Example 10.42.91.01.20.74Example 10.43.01.01.61.46

[0294] According to Table 2 above, it can be confirmed that the Ga and Cl contents in the quantum dot powder increased when precipitated with an acetone solution containing GaCl3 according to Example 1. This means that the quantum dot powder manufactured according to Example 1 is passivated with a metal halide compound.

[0295]

[0296] Simple modifications or changes of the present invention can be easily implemented by a person having ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.< / etga> < / hdda>

Claims

1. Contains quantum dots of the I-III-VI series, The above I-III-VI quantum dots have two or more types of ligands, A quantum dot composition comprising a first ligand which is a reaction product between an aminothiol-based compound and a (meth)acrylate-based compound; and a second ligand which is a metal halide-based compound.

2. In the first paragraph, the aminothiol compound is a quantum dot composition comprising at least one compound represented by the following chemical formula 1: [Chemical Formula 1] (In the above chemical formula 1, L 1 is a substituted or unsubstituted C1 to C10 alkylene group, or a substituted or unsubstituted C1 to C5 alkylene glycol group).

3. A quantum dot composition in the first paragraph, wherein the (meth)acrylate compound comprises at least one of a monofunctional (meth)acrylate and a polyfunctional (meth)acrylate.

4. A quantum dot composition according to claim 1, wherein the reaction product comprises at least one reaction product of a thiol-ene reaction or a hydroamination reaction between the aminothiol compound and the (meth)acrylate.

5. A quantum dot composition according to claim 1, wherein the first ligand comprises at least 50 wt% of the total ligands of the I-III-VI quantum dot.

6. In the first paragraph, the metal halide compound is a quantum dot composition comprising at least one of the following chemical formulas 6-1 and 6-2: [Chemical Formula 6-1] MX2 [Chemical Formula 6-2] MX3 (In the above chemical formulas 6-1 and 6-2, M is Ga or Zn, X is a halide, which is F, Cl, Br, or I.

7. A quantum dot composition according to claim 6, wherein the metal halide compound comprises at least one of GaCl3 and ZnCl2.

8. A quantum dot composition according to claim 1, wherein the second ligand comprises 20 wt% or less of the total ligands of the I-III-VI quantum dot.

9. A quantum dot composition according to claim 1, wherein the I-III-VI quantum dot further comprises an amine compound as a third ligand.

10. In the 9th paragraph, the quantum dot composition comprising at least one compound of the following chemical formula 7: [Chemical Formula 7] (In the above chemical formula 7, L 71 , L 72 are each independently a substituted or unsubstituted C1 to C10 alkyl group. x is between 1 and 100, y is between 0 and 100).

11. A quantum dot composition in claim 9, wherein the sum of the first ligand, the second ligand, and the third ligand comprises 95 wt% or more of the total ligands of the I-III-VI quantum dot.

12. A quantum dot composition according to claim 1, wherein the I-III-VI quantum dot comprises a quantum dot core composed of group 11, group 13, and group 16.

13. A quantum dot composition according to claim 12, wherein the quantum dot core comprises Ag, In, Ga, and S.

14. A quantum dot composition according to claim 1, wherein the composition further comprises at least one of a photocurable monomer having an unsaturated bond, an initiator, a light scattering agent, and a polymerization inhibitor.

15. A cured film comprising a cured product of the quantum dot composition of any one of claims 1 to 14.

16. A display device including the cured film of Article 15.

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