KR20220106015A - Quantum dot, and ink composition, optical member and electronic device including the same - Google Patents

Abstract

The present invention relates to a quantum dot and a light-emitting device, electronic device, and optical member including the same, the quantum dot comprising: a core including a crystal of a first semiconductor; a shell including one or more crystals of a second semiconductor disposed on the core; a first region including a first ligand provided on the shell; and an outer layer that is provided on the first region and includes an oligomer or polymer containing metal and polar organic groups.

Description

Quantum dot, ink composition including same, optical member and electronic device {Quantum dot, and ink composition, optical member and electronic device including the same}

It relates to a quantum dot, an ink composition including the same, an optical member, and an electronic device.

A quantum dot is a nanocrystal of a semiconductor material, and is a material exhibiting a quantum confinement effect. When the quantum dot receives light from an excitation source and reaches an energy excited state, it emits energy according to a corresponding energy band gap. At this time, even in the case of the same material, since the wavelength varies depending on the particle size, light in a desired wavelength region can be obtained by controlling the size of the quantum dot, and characteristics such as excellent color purity and high luminous efficiency can be exhibited. Therefore, it can be applied to various devices.

In addition, quantum dots may be used as materials that perform various optical functions (eg, light conversion functions) among optical members. Quantum dots, as nano-sized semiconductor nanocrystals, may have different energy band gaps by controlling the size and composition of the nanocrystals, and thus may emit light of various emission wavelengths.

The optical member including such quantum dots may have a thin film form, for example, a thin film patterned for each sub-pixel. Such an optical member may be utilized as a color conversion member of a device including various light sources.

An object of the present invention is to provide a quantum dot having excellent dispersibility and improved efficiency in a polar solvent without desorption of the nonpolar ligand with respect to the quantum dot surface-coordinated with the non-polar ligand, and to provide an ink composition, an optical member, and an electronic device including the same do.

According to one aspect, a core including a first semiconductor crystal; a shell comprising one or more second semiconductor crystals disposed on the core; a first region comprising a first ligand provided on the shell; and an outer layer provided on the first region and including a polymer including a metal and a polar organic group; including, a quantum dot is provided.

According to another aspect, an ink composition including the quantum dots is provided.

According to another aspect, an optical member including the quantum dots is provided.

According to another aspect, the first electrode; a second electrode opposite the first electrode; and an intermediate layer interposed between the first electrode and the second electrode, and a color conversion member provided outside of at least one of the first electrode and the second electrode opposite to the intermediate layer, wherein the color conversion member is An electronic device including a quantum dot is provided.

The present invention not only increases the dispersibility of the quantum dots in a polar solvent without desorption of the non-polar ligand by introducing a coating layer containing a polar ligand to the quantum dots surface-coordinated with a non-polar ligand, but also increases the dispersibility of the quantum dots from the introduction of the coating layer. It has the advantage that the efficiency is improved by blocking the loss of the semiconductor metal.

1 is a schematic diagram of a quantum dot according to an embodiment of the present invention.
2 is a diagram schematically showing the structure of a light emitting device according to an embodiment of the present invention.
3 is a diagram schematically showing the structure of a light emitting device according to an embodiment of the present invention.
4 is a graph showing the measurement of photoluminescence quantum efficiency of Reference Examples 1 and 2 and Controls 1 and 2;
5 is a photograph showing quantum dot dispersibility with respect to Controls 1 and 2.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. Effects and features of the present invention, and a method for achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and when described with reference to the drawings, the same or corresponding components are given the same reference numerals, and the overlapping description thereof will be omitted. .

In the following embodiments, terms such as first, second, etc. are used for the purpose of distinguishing one component from another, not in a limiting sense.

In the following examples, the singular expression includes the plural expression unless the context clearly dictates otherwise.

In the following embodiments, terms such as include or have means that the features or components described in the specification are present, and the possibility that one or more other features or components may be added is not excluded in advance.

In the following embodiments, when various components such as layers, films, regions, plates, etc. are “on” other components, this is not only when they are “on” other components, but also when other components are interposed therebetween. including cases where In addition, in the drawings for convenience of description, the size of the components may be exaggerated or reduced. For example, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar.

[Quantum dot]

1 is a schematic diagram schematically showing the structure of a quantum dot according to an embodiment of the present invention.

Referring to FIG. 1 , a quantum dot 1 includes a core 11 including a first semiconductor crystal; a shell (12) comprising at least one second semiconductor crystal disposed on said core; a first region (13) comprising a first ligand provided on the shell; and an outer layer 14 provided on the first region and comprising a polymer or oligomer comprising a metal and a polar organic group.

The quantum dot has a core/shell structure including a semiconductor crystal, a first region including a non-polar ligand is disposed on a surface of the shell, and surrounds the first region on the first region, and is represented by Chemical Formula 1 By including the outer layer including the polymer of the monomer to be used, the loss of the semiconductor metal and the desorption of the first ligand are prevented, thereby preventing deterioration of the quantum dots.

In addition, the quantum dot includes an outer layer including a polymer including a metal and a polar organic group, so that a part of the metal lost from the shell surface is supplemented, so that quantum efficiency can be improved, as well as containing a metal organic group The polymer improves dispersibility and compatibility in a polar solvent, thereby improving workability.

According to one embodiment, the metal may include Cd, Zn, Hg, Mg, Ga, Al, In, Sn, Pb, Si, Ge, Si, Ag, Cu, or a combination thereof, but must be limited thereto it's not going to be

For example, the metal may be Zn, In, Cd, or Ga.

According to an embodiment, the metal may include the same metal as the metal included in the second semiconductor crystal.

For example, when the second semiconductor crystal includes a combination of two or more metals, the second semiconductor crystal may include the same metal as any one of the two or more metals.

According to one embodiment, the polar organic group may include a hydroxyl group, a carbonyl group, an acryl group, an ester group, an ether group, a carboxyl group, an epoxy group, a halogen group, or a combination thereof, but is not limited thereto. Any group that provides polarity to

For example, the polar organic group may be an acryl group, an epoxy group, an ether group, or a carboxyl group.

According to one embodiment, the polymer or oligomer may include an oligomer or polymer of a monomer represented by the following Chemical Formula 1:

<Formula 1>

In Formula 1,

M includes Cd, Zn, Hg, Mg, Ga, Al, In, Sn, Pb, Si, Ge, Si, Ag, Cu, or a combination thereof,

Y is selected from ionic groups,

A ₁ and A ₂ are each independently selected from a C ₁ -C ₂₀ alkylene group unsubstituted or substituted with at least one R _10a , and a C ₂ -C ₂₀ alkenylene group unsubstituted or substituted with at least one R _10a can be,

a1 and a2 are each independently an integer selected from 0 to 10,

When a1 is an integer of 2 or more, A ₁ of 2 or more are the same as or different from each other, and when a2 is an integer of 2 or more, A ₂ of 2 or more are the same or different from each other,

P ₁ and P ₂ are independently of each other *-O-*', *-S-*', *-C(=O)-*', *-S(=O) ₂ -*', *-C( =O)(O)-*', *-C(R ₁ )=C(R ₂ )-C(=O)OR ₃ -*', *-OC(=O)-C(R ₁ )=C (R ₂ )-*', *-C(R ₁ )(R ₂ )-*' is selected from;

b1 and b2 are each independently an integer selected from 1 to 10,

When b1 is an integer of 2 or more, P ₁ of 2 or more is the same as or different from each other, and when b2 is an integer of 2 or more, P ₂ of 2 or more are the same or different from each other,

c1 and c2 are integers selected from 0 to 10;

When c1 is an integer of 2 or more, *-(A ₁ ) _a1 -(P ₁ ) _b1 -*' of 2 or more are the same as or different from each other, and when c2 is an integer of 2 or more, 2 or more *-(A ₂ ) _a2 -(P ₂ ) _b2 -*' are the same as or different from each other,

R ₁ and R ₂ are each independently selected from hydrogen, a hydroxyl group, an alkoxy group, an epoxy group and a halogen group,

R _10a is selected from hydrogen, a C ₁ -C ₂₀ alkyl group, and a C ₁ -C ₂₀ alkenyl group,

n is an integer selected from 1 to 5,

는 서로 동일하거나 상이하고,2 or greater if n is an integer greater than or equal to 2

are the same or different from each other,

Z is a crosslinkable group including at least one of an ethylenically unsaturated group, an epoxy group, an alkoxy group, and an isocyanate group.

According to one embodiment, the ionic group may be an anionic group. For example, the ionic group may be a thiol group, a carboxyl group, an amine group, a phosphoric acid group, a sulfuric acid group, or a nitric acid group. Herein, the term “ionic group” refers to a group capable of forming a salt with a metal by being in the form of an ion in an aqueous solution.

According to one embodiment, the ionic group may be a carboxyl group.

According to one embodiment, the polymer may further include an ionic group, and the ionic group may be combined with a metal to exist in the form of a metal salt.

According to one embodiment, the outer layer may further include the above-mentioned monomer.

According to one embodiment, M in Formula 1 may include the same metal as the metal included in the second semiconductor crystal. Thereby, a portion of the monomer that does not form a polymer among the monomers may be dispersed into the first region to heal defects on the shell surface, thereby improving quantum efficiency of quantum dots.

According to an embodiment, the polymer may include a cross-linked polymer linked by cross-linking with light of the cross-linkable group, for example, UV light, heat, or cross-linking by a cross-linking group.

For example, the crosslinked polymer may be a network crosslinked polymer.

According to one embodiment, when a1 is 0, A ₁ may be directly bonded to a single bond, a group adjacent to Y may be directly bonded, and when a2 is 0, A ₂ may be bonded to a single bond, and a group adjacent to P ₁ may be directly bonded. .

According to one embodiment, A ₁ and A ₂ may be each independently a C ₁ -C ₁₀ alkylene group. For example, A ₁ and A ₂ may each be an ethylene group.

According to an embodiment, the P ₁ and P ₂ are each independently *-O-*', *-S-*', *-C(=O)-*', or *-C(=O)( O)-*'. For example, P ₁ and P ₂ may each be *-O-*'.

According to one embodiment, Z may be a group selected from the following Chemical Formulas 1-1 to 1-6:

In Formulas 1-1 to 1-6,

R ₁₁ to R ₁₅ may be each independently selected from hydrogen, -F, -Cl, -Br, -I, a C ₁ -C ₂₀ alkyl group, and a C ₁ -C ₂₀ alkenyl group.

For example, R ₁₁ to R ₁₅ are each independently

Hydrogen, -F, -Cl, -Br, -I, methyl group, ethyl group, n -propyl group, isopropyl group, n -butyl group, sec -butyl group, isobutyl group, tert -butyl group, n -pentyl group , tert -pentyl group, neopentyl group, isopentyl group, sec -pentyl group, 3-pentyl group, sec -isopentyl group, n -hexyl group, isohexyl group, sec -hexyl group, tert -hexyl group, n -heptyl group, isoheptyl group, sec -heptyl group, tert -heptyl group, n -octyl group, isooctyl group, sec -octyl group, tert -octyl group, n -nonyl group, isononyl group, sec -nonyl group, It may be selected from a tert -nonyl group, n -decyl group, isodecyl group, sec -decyl group, and tert -decyl group, but is not limited thereto.

For example, R ₁₁ to R ₁₃ are each independently hydrogen, methyl group, ethyl group, n -propyl group, isopropyl group, n -butyl group, sec -butyl group, isobutyl group, tert -butyl group, n -pentyl group, tert -pentyl group, neopentyl group, isopentyl group, sec -pentyl group, 3-pentyl group, sec -isopentyl group, n -hexyl group, isohexyl group, sec -hexyl group, and tert- It may be selected from a hexyl group.

According to one embodiment, the first ligand may include a C ₁ -C ₂₀ hydrocarbon group.

For example, the first ligand may include a C ₁ -C ₂₀ hydrocarbon group including at least one ethylenically unsaturated group.

According to one embodiment, the first ligand may further include an ionic group. For example, the ionic group may be a thiol group, a carboxyl group, an amine group, a phosphoric acid group, a sulfuric acid group, or a nitric acid group.

According to one embodiment, the first ligand may be composed of an ionic group and a C ₁ -C ₂₀ hydrocarbon group. For example, the ionic group may be coordinated to the surface of the shell, and the C ₁ -C ₂₀ hydrocarbon group may be oriented toward the outer layer. For example, the first ligand may be oleic acid.

According to an embodiment, the first semiconductor and the second semiconductor are each independently selected from a group III-VI semiconductor compound; group II-VI semiconductor compounds; III-V semiconductor compounds; III-VI semiconductor compounds; Group I-III-VI semiconductor compounds; group IV-VI semiconductor compounds; Group IV element or compound; or any combination thereof.

Examples of the group II-VI semiconductor compound include binary compounds such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS and the like; triatomic compounds such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgZnTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, etc.; quaternary compounds such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe and the like; or any combination thereof; may include.

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

Examples of the group III-VI semiconductor compound include binary compounds such as GaS, GaSe, Ga ₂ Se ₃ , GaTe, InS, InSe, In ₂ Se ₃ , InTe, and the like; ternary compounds such as InGaS ₃ , InGaSe ₃ and the like; or any combination thereof; may include.

Examples of the group I-III-VI semiconductor compound include ternary compounds such as AgInS, AgInS ₂ , CuInS, CuInS ₂ , CuGaO ₂ , AgGaO ₂ , AgAlO ₂ ; or any combination thereof; may include.

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

The group IV element or compound may be a single element compound such as Si or Ge; binary compounds such as SiC, SiGe, and the like; or any combination thereof.

Each element included in the multi-element compound such as the di-element compound, the ternary compound, and the quaternary compound may be present in the quantum dot particles at a uniform or non-uniform concentration.

Meanwhile, the quantum dot may have a single structure or a core-shell double structure in which the concentration of each element included in the quantum dot is uniform. For example, the material included in the core and the material included in the shell may be different from each other.

The shell of the quantum dot may serve as a protective layer for maintaining semiconductor properties by preventing chemical modification of the core and/or a charging layer for imparting electrophoretic properties to the quantum dots. The shell may be single-layered or multi-layered. The interface between the core and the shell may have a concentration gradient in which the concentration of elements present in the shell decreases toward the center.

According to one embodiment, the first semiconductor is GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb , AlPAs, AlPSb, InGaP, InAlP, InNP, InNAs, InNSb, InPAs, InPSb, InZnP, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlPSb, InAlNAs or any combination thereof,

The second semiconductor is CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgS, MgSe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeZnTe, ZnSTe, HgSeTe, HgST , CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe MgZnS, MgZnSe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSe, HgZnSe, any combination of, including but not limited to, any combination thereof not.

According to one embodiment, the shell may be a single layer or multiple layers.

According to one embodiment, the shell may be a composite single-layer shell including two different types of second semiconductor crystals. In this case, the first region including the above-described first ligand may be provided on at least a portion of the composite single-layer shell or may be provided to cover the entire outer surface of the composite single-layer shell.

According to one embodiment, the shell may include two different types of second semiconductor crystals including Zn metal.

According to one embodiment, the shell may include two different types of group II-IV semiconductor compounds. For example, the shell may include ZnSe and ZnS.

According to an embodiment, the shell may include a double-layered shell including a first shell and a second shell, and the first shell may be disposed between the core and the second shell. In this case, the first shell and the second shell may include different second semiconductor crystals.

For example, the first shell may include ZnSe, and the second shell may include ZnS.

The quantum dots emit visible light. For example, the quantum dots may emit light having various maximum emission wavelengths according to the size of the diameter. As an example, the quantum dots may emit light having a maximum emission wavelength of 430 nm to 800 nm. Therefore, when the quantum dots are applied to the color conversion member, high luminance and high color purity may be realized.

According to one embodiment, the average diameter of the quantum dots may be 1 nm to 15 nm. For example, the average diameter of the quantum dots may be 2 nm to 13 nm or 2 nm to 10 nm.

According to one embodiment, the shape of the quantum dot is not particularly limited, and may have a shape generally used in the art. For example, the quantum dots may have a shape such as a spherical, pyramidal, multi-arm or cubic nanoparticle, nanotube, nanowire, nanofiber, or nanoplate shape.

[ink composition]

According to another aspect, an ink composition including the above-described quantum dots is provided.

According to one embodiment, the ink composition may be a solvent-free type ink composition that does not substantially include a solvent. For example, the ink composition may include a solvent that inevitably remains after the quantum dot is manufactured, and the content of the solvent may be about 5% by weight or less based on the total weight of the composition. The solvent remaining in the quantum dots may be removed through an additional purification process.

Since the ink composition does not include a solvent, the process simplification and economic advantages may be achieved by omitting the solvent removal step.

According to one embodiment, the content of the quantum dots in the ink composition is 0.1 wt% to 50 wt%, specifically 10 wt% to 50 wt%, or 10 wt% to 45 wt% based on the total weight of the composition can

The viscosity of the ink composition may be 1 cP to 30 cP at room temperature (eg, 25° C.). For example, the viscosity of the ink composition may be 5 cp to 30 cp, 10 cp to 30 cp, or 20 to 25 cp. The ink composition satisfying the above viscosity range may be suitable for manufacturing a color conversion member positioned outside the light emitting device or manufacturing a quantum dot light emitting layer.

According to one embodiment, the ink composition may further include a polymerization initiator. The polymerization initiator may include a thermal polymerization initiator and/or a photoinitiator.

As the thermal polymerization initiator, compounds capable of forming radicals by heat may be used without limitation, and as the thermal polymerization initiator, a persulfate-containing acid-based compound, for example, sodium persulfate (Sodium persulfate; Na ₂ S ₂ 0 ₈ ) , potassium persulfate (Potassium persulfate; K ₂ S ₂ 0 ₈ ), ammonium persulfate (Ammonium persulfate; (NH ₄ ) ₂ S ₂ 0 ₈ ), azo-based compounds, for example 2,2-azobis-(2 -Amidinopropane)dihydrochloride (2,2-azobis(2-amidinopropane) dihydrochloride), 2,2-azobis-(N,N-dimethylene)isobutyramide dihydrochloride (2,2-azobis- (N,N-dimethylene)isobutyramidine dihydrochloride), 2-(carbamoylazo)isobutyronitrile (2-(carbamoylazo)isobutylonitril), 2,2-azobis[2-(2-imidazolin-2-yl) ) propane] dihydrochloride (2,2-azobis [2- (2- imidazolin-2-yl) propane] dihydrochloride), 4,4-azobis- (4-cyanovaleric acid ) (4,4- azobis-(4-cyanovaleric acid)), hydrogen peroxide, or a combination thereof.

When the thermal polymerization initiator is used, 0.01 to 15 parts by weight based on the total weight of the ink composition may be used.

As the photopolymerization initiator, any compound capable of forming radicals by ultraviolet light having a maximum emission wavelength of 200 nm to 400 nm may be used without limitation, and the photopolymerization initiator may include, for example, arylsulfonium and aryldiazonium. or a compound or organosilane compound comprising a combination of any one of cations containing arylammonium and any one of anions containing AsF ₆ ^- , SbF ₆ ^- , PF ₆ ^- , or tetrakis (pentafluorophenyl) borate may include

When the photopolymerization initiator is used, it may be used in an amount of 0.01 to 15 parts by weight based on the total weight of the ink composition.

According to one embodiment, the ink composition may further include various additives in order to improve the ejection and applicability of the ink composition in a range that does not affect the physical properties of the quantum dots, and to improve the optical properties of the thin film cured therefrom. .

For example, the ink composition may further include a well-known dispersing agent, a viscosity modifier, etc. to improve ejection properties and coating properties, and a well-known surfactant, a scattering agent, an antifoaming agent, and the like to improve optical properties of the cured thin film. It may further include a UV stabilizer, a moisture absorbent, an antioxidant, and the like. In this case, the additive may be used in an amount in a range that does not affect the physical properties of the quantum dots.

According to one embodiment, the ink composition may further include a diacrylate-based monomer. For example, the diacrylate-based monomer may include an alkyldiol diacrylate monomer. For example, the alkyldiol diacrylate monomer may include a hexanediol diacrylate monomer.

According to another aspect, the ink composition may optionally further include a solvent.

The solvent is not particularly limited as long as it can uniformly disperse the quantum dots. For example, the solvent may be an organic solvent.

Specifically, the solvent may be selected from chlorine-based, ether-based, ester-based, ketone-based, aliphatic hydrocarbon-based and aromatic hydrocarbon-based solvents, but is not limited thereto.

More specifically, the solvent is dichloromethane, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, o-dichlorobenzene, cyclohexylbenzene; tetrahydrofuran, dioxane, anisole, 4-methylanisole, butyl phenylether; toluene, xylene, mesitylene, ethylbenzene, n-hexylbenzene, cyclohexylbenzene, trimethylbenzene, tetrahydronaphthalene; cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, dodecane, hexadecane, oxadecane; acetone, methyl ethyl ketone, cyclohexanone, acetophenone; ethyl acetate, butyl acetate, methylsolvate acetate, ethylsolveacetate, methyl benzoate, ethyl benzoate, butyl benzoate, 3-phenoxy benzoate, or any combination thereof.

The content of the solvent in the ink composition may be 80 parts by weight to 99.9 parts by weight, specifically 90 parts by weight to 99.8 parts by weight, based on the total weight of the composition, but is not limited thereto. When the above-described range is satisfied, the quantum dots may be appropriately dispersed in the ink composition, and may have a solid concentration suitable for a solution process.

According to one embodiment, the ink composition including the above-described quantum dots may be provided on the outside of the light emitting device to form an optical member. In this case, the optical member may be a color conversion member having a function of absorbing light emitted from the light emitting device and emitting light having a different wavelength band.

[Electronic Device]

Hereinafter, an electronic device including the above-described quantum dots will be described.

The electronic device may include: the quantum dots and a first electrode; a second electrode; and a light emitting device including an intermediate layer interposed between the first electrode and the second electrode.

According to an embodiment, the electronic device may include a liquid crystal display device, an organic light emitting display device, or an inorganic light emitting display device.

For example, when the electronic device further includes a liquid crystal, the electronic device may be a liquid crystal display device. In this case, the light emitting device may serve as a light source, and the quantum dots may be included outside the light emitting device and the liquid crystal to serve as a color conversion member.

As another example, when the intermediate layer of the light emitting device includes an emission layer, and the emission layer includes an organic material, the electronic device may be an organic light emitting display device. In this case, the light emitting device may serve as a light source, and the quantum dots may be included outside the light emitting device to serve as a color conversion member.

As another example, when the intermediate layer of the light emitting device includes an emission layer, and the emission layer includes an inorganic material, for example, the quantum dots, the electronic device may be an inorganic light emitting display device.

The electronic device may further include a thin film transistor in addition to the above-described light emitting device. The thin film transistor may include a source electrode, a drain electrode, and an active layer, and any one of the source electrode and the drain electrode and any one of the first electrode and the second electrode of the light emitting device may be electrically connected.

The thin film transistor may further include a gate electrode, a gate insulating layer, and the like.

The active layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, or the like.

The electronic device may further include a sealing unit sealing the light emitting device. The sealing part allows light from the light emitting device to be taken out, while at the same time blocking the penetration of external air and moisture into the light emitting device. The sealing part may be a sealing substrate including a transparent glass substrate or a plastic substrate. The encapsulation unit may be a thin film encapsulation layer including one or more organic and/or inorganic layers. When the encapsulation part is a thin film encapsulation layer, the electronic device may be flexible.

Various functional layers may be additionally disposed on the sealing part according to the purpose of the electronic device. Examples of the functional layer may include the color filter, color conversion layer, touch screen layer, polarization layer, and the like. The touch screen layer may be a pressure-sensitive touch screen layer, a capacitive touch screen layer, or an infrared touch screen layer.

Hereinafter, the electronic device 3 including the light emitting device 320 according to an embodiment will be described in detail with reference to FIG. 2 .

The electronic device 3 includes a first substrate 310 , a light emitting device 320 , and a second substrate 340 .

The quantum dots may be included outside the light emitting device 320 (ie, on the first electrode and/or the second electrode). Specifically, the quantum dots may be included in the second substrate 340 positioned outside the light emitting device 320 . The second substrate 340 may serve as a color conversion member, and the light emitting device 320 may serve as a light source.

The light emitting device 320 includes a first electrode 321 , a second electrode 323 , and an intermediate layer 322 interposed between the first electrode 321 and the second electrode 323 .

The electronic device 3 may be an organic light emitting diode display. Accordingly, the light emitting device 320 may include an organic light emitting layer in the intermediate layer 322 .

A pixel defining layer 330 may be disposed on the first electrode 321 . The pixel defining layer 330 exposes a predetermined area of the first electrode 321 , and an intermediate layer 322 may be disposed in the exposed area.

In an embodiment, one region 341 of the second substrate 340 may include the semiconductor nanoparticles. In this case, the second substrate 340 may be positioned in the traveling direction of the light emitted from the light emitting device 320 .

The quantum dots may absorb blue light to emit visible light. Accordingly, the second substrate 340 may be designed to absorb blue light and emit wavelengths of various color ranges. Accordingly, the light emitting device 320 emits blue light, for example, blue light having a maximum emission wavelength of 400 nm to 490 nm, and the thin film absorbs the blue light to provide visible light, for example, a maximum emission wavelength of 445 nm. to 650 nm visible light.

In an embodiment, the second substrate 340 may further include a scatterer.

In an embodiment, the second substrate 340 further includes another region (not shown) distinct from the one region 341 , the other region does not include the semiconductor nanoparticles, and the other region is a light emitting device. Blue light from (not shown) may be transmitted. Specifically, only one region 341 may include the semiconductor nanoparticles, and the other region may include only scatterers.

In an embodiment, in the second substrate 340 , a light blocking pattern 344 may be further formed between the one region and the other region.

Hereinafter, an electronic device 4 according to another exemplary embodiment will be described in detail with reference to FIG. 3 .

The electronic device 4 includes a first substrate 410 and a light emitting device 420 .

The light emitting device 420 includes a first electrode 421 , a second electrode 423 , and an intermediate layer 422 interposed between the first electrode 421 and the second electrode 423 .

The quantum dots may be included in the intermediate layer 422 , and specifically, may be included in the light emitting layer included in the intermediate layer 422 .

The quantum dots may emit visible light. Accordingly, the light emitting device 420 may be designed to emit wavelengths of various color ranges. For example, the quantum dots may emit visible light having a maximum emission wavelength of 445 nm to 650 nm.

The intermediate layer 422 may further include an auxiliary layer between the emission layer and the first electrode and/or between the emission layer and the second electrode. The auxiliary layer may be in direct contact with the light emitting layer. The auxiliary layer may improve thin film characteristics of the light emitting layer.

The intermediate layer 422 may further include a first charge transport region interposed between the emission layer and the first electrode and/or a second charge transport region interposed between the emission layer and the second electrode.

[Manufacturing method of quantum dots]

A method of manufacturing the quantum dots will be described in detail.

The manufacturing method of the quantum dot includes: forming a core particle made of a first semiconductor compound; contacting the core particle with a second semiconductor compound precursor to form a core/shell particle including a shell made of a second semiconductor compound; , and forming an outer layer on the core/shell particles.

The first semiconductor compound may contain indium (In), gallium (Ga), and phosphorus (P), and the second semiconductor compound may contain zinc (Zn), selenium (Se), and sulfur (S).

According to one embodiment, the second semiconductor compound precursor may include a second semiconductor compound first precursor and a second precursor. For example, the first precursor may contain zinc (Zn) and selenium (Se), and the second precursor may contain zinc (Zn) and sulfur (S).

According to an embodiment, the contacting of the core particle with the second semiconductor compound precursor includes (i) contacting the core particle and the second semiconductor compound with the first precursor compound and (ii) followed by the second semiconductor compound preparation contacting the biprecursor compound.

Step (i) may be performed at a temperature of 290°C to 350°C, for example, at a temperature of 300°C to 340°C for 30 minutes to 90 minutes, for example, 50 minutes to 70 minutes, wherein step (ii) is It may be carried out at a temperature of 290 °C to 350 °C, for example, at a temperature of 300 °C to 340 °C for 60 minutes to 120 minutes, for example 80 minutes to 100 minutes.

Accordingly, a composite single-layer shell or a double-layer shell including two kinds of second semiconductor compounds may be formed on the core particle.

According to an embodiment, the forming of the outer layer may include providing an oligomer or polymer including a metal and a polar organic group on the core/shell particle. In this case, the metal may be a metal constituting the second semiconductor compound, for example, Zn.

In one embodiment, after the step of forming the core particles, a purification step and/or a separation step may be further included, which may be omitted.

In one embodiment, the solvent may be an organic solvent. For example, the solvent may be trioctylamine, oleylamine, 1-octadecene (ODE), or the like.

Details of the method for manufacturing the semiconductor nanoparticles can be recognized by those skilled in the art with reference to the Examples to be described later.

[Definition of Terms]

In the present specification, a C ₃ -C ₆₀ carbocyclic group refers to a cyclic group having 3 to 60 carbon atoms and consisting only of carbon, and the C ₁ -C ₆₀ heterocyclic group is, in addition to carbon, a carbon number including 1 to carbon atoms further including a hetero atom. It means a cyclic group of 60.

In the present specification, the cyclic group includes both the C ₃ -C ₆₀ carbocyclic group and the C ₁ -C ₆₀ heterocyclic group.

In the present specification, the term cyclic group, C ₃ -C ₆₀ carbocyclic group, or C ₁ -C ₆₀ heterocyclic group is condensed to any cyclic group according to the structure of the formula in which the term is used. It may be a group, a monovalent group, or a polyvalent group (eg, a divalent group, a trivalent group, a tetravalent group, etc.). For example, the "benzene group" may be a benzo group, a phenyl group, a phenylene group, etc., which can be easily understood by those skilled in the art according to the structure of the chemical formula including the "benzene group".

For example, examples of the monovalent C ₃ -C ₆₀ carbocyclic group and the monovalent C ₁ -C ₆₀ heterocyclic group include a C ₃ -C ₁₀ cycloalkyl group, a C ₁ -C ₁₀ heterocycloalkyl group, C ₃ -C ₁₀ cycloalkenyl group, C ₁ -C ₁₀ heterocycloalkenyl group, C ₆ -C ₆₀ aryl group, C ₁ -C ₆₀ heteroaryl group, monovalent non-aromatic condensed polycyclic group, and monovalent non-aromatic hetero may include a condensed polycyclic group, and examples of a divalent C ₃ -C ₆₀ carbocyclic group and a monovalent C ₁ -C ₆₀ heterocyclic group include a C ₃ -C ₁₀ cycloalkylene group, C ₁ -C ₁₀ Heterocycloalkylene group, C ₃ -C ₁₀ cycloalkenylene group, C ₁ -C ₁₀ heterocycloalkenylene group, C ₆ -C ₆₀ arylene group, C ₁ -C ₆₀ heteroarylene group, divalent non-aromatic condensed polycyclic ring group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group.

In the present specification, the C ₁ -C ₆₀ alkyl group refers to a linear or branched aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, n -propyl group, an isopropyl group, n -butyl group, sec -butyl group, isobutyl group, tert -butyl group, n -pentyl group, tert -pentyl group, neopentyl group, isopentyl group, sec -pentyl group, 3-pentyl group, sec -iso pentyl group, n -hexyl group, isohexyl group, sec -hexyl group, tert -hexyl group, n -heptyl group, isoheptyl group, sec -heptyl group, tert -heptyl group, n -octyl group, isooctyl group, sec -octyl group, tert -octyl group, n -nonyl group, isononyl group, sec -nonyl group, tert -nonyl group, n -decyl group, isodecyl group, sec -decyl group, tert -decyl group, etc. are included. . In the present specification, the C ₁ -C ₆₀ alkylene group refers to a divalent group having the same structure as the C ₁ -C ₆₀ alkyl group.

In the present specification, the C ₂ -C ₆₀ alkenyl group refers to a monovalent hydrocarbon group including one or more carbon-carbon double bonds in the middle or terminal of the C ₂ -C ₆₀ alkyl group, and specific examples thereof include an ethenyl group, a propenyl group , a butenyl group, and the like. In the present specification, the C ₂ -C ₆₀ alkenylene group refers to a divalent group having the same structure as the C ₂ -C ₆₀ alkenyl group.

In the present specification, the C ₂ -C ₆₀ alkynyl group refers to a monovalent hydrocarbon group including one or more carbon-carbon triple bonds in the middle or at the terminal of the C ₂ -C ₆₀ alkyl group, and specific examples thereof include an ethynyl group, a propynyl group etc. are included. In the present specification, the C ₂ -C ₆₀ alkynylene group refers to a divalent group having the same structure as the C ₂ -C ₆₀ alkynyl group.

In the present specification, the C ₁ -C ₆₀ alkoxy group refers to a monovalent group having the formula of -OA ₁₀₁ (here, A ₁₀₁ is the C ₁ -C ₆₀ alkyl group), and specific examples thereof include a methoxy group, an ethoxy group , an isopropyloxy group, and the like.

In the present specification, the C ₃ -C ₁₀ cycloalkyl group refers to a monovalent saturated hydrocarbon cyclic group having 3 to 10 carbon atoms, and specific examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclohep group. It means a tyl group, a cyclooctyl group, and the like.

In the present specification, the C ₁ -C ₁₀ heterocycloalkyl group refers to a monovalent cyclic group having 1 to 10 carbon atoms and further including at least one hetero atom as a ring-forming atom in addition to a carbon atom. In the present specification, the C ₁ -C ₁₀ heterocycloalkylene group refers to a divalent group having the same structure as the C ₁ -C ₁₀ heterocycloalkyl group.

In the present specification, the C ₃ -C ₁₀ cycloalkenyl group is a monovalent cyclic group having 3 to 10 carbon atoms, and has at least one carbon-carbon double bond in the ring, but refers to a group that does not have aromaticity, Specific examples thereof include a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group, and the like. In the present specification, the C ₃ -C ₁₀ cycloalkenylene group refers to a divalent group having the same structure as the C ₃ -C ₁₀ cycloalkenyl group.

In the present specification, the C ₁ -C ₁₀ heterocycloalkenyl group is a monovalent cyclic group having 1 to 10 carbon atoms that further includes at least one hetero atom as a ring-forming atom in addition to a carbon atom, and comprises at least one double bond in the ring. have Specific examples of the C ₁ -C ₁₀ heterocycloalkenyl group include 4,5-dihydro-1,2,3,4-oxatriazolyl group, 2,3-dihydrofuranyl group, 2,3-dihydro A thiophenyl group and the like are included. In the present specification, the C ₁ -C ₁₀ heterocycloalkenylene group refers to a divalent group having the same structure as the C ₁ -C ₁₀ heterocycloalkenyl group.

In the present specification, the C ₆ -C ₆₀ aryl group refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms, and the C ₆ -C ₆₀ arylene group is a carbocyclic aromatic system having 6 to 60 carbon atoms. It means a divalent (divalent) group having Specific examples of the C ₆ -C ₆₀ aryl group include a phenyl group, a pentalenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group , triphenylenyl group, pyrenyl group, chrysenyl group, perylenyl group, pentaphenyl group, a heptalenyl group, a naphthacenyl group, a picenyl group, a hexacenyl group, a pentacenyl group, a rubycenyl group, a coronenyl group, an ovalenyl group, and the like. When the C ₆ -C ₆₀ aryl group and the C ₆ -C ₆₀ arylene group include two or more rings, the two or more rings may be condensed with each other.

In the present specification, the C ₁ -C ₆₀ heteroaryl group refers to a monovalent group having, in addition to carbon atoms, at least one hetero atom as a ring-forming atom and having a heterocyclic aromatic system having 1 to 60 carbon atoms, and C ₁ The -C ₆₀ heteroarylene group refers to a divalent group having, in addition to carbon atoms, at least one hetero atom as a ring-forming atom and having a heterocyclic aromatic system having 1 to 60 carbon atoms. Specific examples of the C ₁ -C ₆₀ heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, a benzoquinolinyl group, an isoquinolinyl group, benzo an isoquinolinyl group, a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, a benzoquinazolinyl group, a cinolinyl group, a phenanthrolinyl group, a phthalazinyl group, a naphthyridinyl group, and the like. When the C ₁ -C ₆₀ heteroaryl group and the C ₁ -C ₆₀ heteroarylene group include two or more rings, the two or more rings may be condensed with each other.

In the present specification, a monovalent non-aromatic condensed polycyclic group has two or more rings condensed with each other, contains only carbon as a ring-forming atom, and the entire molecule is non-aromatic. means a monovalent group having (eg, having 8 to 60 carbon atoms). Specific examples of the monovalent non-aromatic condensed polycyclic group include an indenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, an indenophenanthrenyl group, an indenoanthracenyl group, and the like. In the present specification, the divalent non-aromatic condensed polycyclic group refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

In the present specification, a monovalent non-aromatic condensed heteropolycyclic group includes at least one hetero atom in addition to a carbon atom as a ring-forming atom, wherein two or more rings are condensed with each other, and the entire molecule is means a monovalent group having non-aromatic properties (eg, having 1 to 60 carbon atoms). Specific examples of the monovalent non-aromatic condensed heteropolycyclic group include a pyrrolyl group, a thiophenyl group, a furanyl group, an indolyl group, a benzoindolyl group, a naphthoindolyl group, an isoindoleyl group, a benzoisoindolyl group, a naphthoisoindolyl group , benzosilolyl group, benzothiophenyl group, benzofuranyl group, carbazolyl group, dibenzosilolyl group, dibenzothiophenyl group, dibenzofuranyl group, azacarbazolyl group, azafluorenyl group, azadibenzosilolyl group, azadi Benzothiophenyl group, azadibenzofuranyl group, pyrazolyl group, imidazolyl group, triazolyl group, tetrazolyl group, oxazolyl group, isoxazolyl group, thiazolyl group, isothiazolyl group, oxadiazolyl group, thia Diazolyl group, benzopyrazolyl group, benzoimidazolyl group, benzooxazolyl group, benzothiazolyl group, benzooxadiazolyl group, benzothiadiazolyl group, imidazopyridinyl group, imidazopyrimidinyl group, imidazo Triazinyl group, imidazopyrazinyl group, imidazopyridazinyl group, indenocarbazolyl group, indolocarbazolyl group, benzofurocarbazolyl group, benzothienocarbazolyl group, benzosilolocarbazolyl group, Benzoindolocarbazolyl group, benzocarbazolyl group, benzonaphthofuranyl group, benzonaphthothiophenyl group, benzonaphthosilolyl group, benzofurodibenzofuranyl group, benzofurodibenzothiophenyl group, benzothienodibenzothiophenyl group , etc. are included. In the present specification, the condensed divalent non-aromatic heteropolycyclic group refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

In the present specification, the C ₆ -C ₆₀ aryloxy group refers to -OA ₁₀₂ (here, A ₁₀₂ is the C ₆ -C ₆₀ aryl group), and the C ₆ -C ₆₀ arylthio group is -SA ₁₀₃ (here , A ₁₀₃ represents the above C ₆ -C ₆₀ aryl group).

In the present specification, "R _10a " is,

deuterium (-D), -F, -Cl, -Br, -I, a hydroxyl group, a cyano group, or a nitro group;

Deuterium, -F, -Cl, -Br, -I, hydroxyl group, cyano group, nitro group, C ₃ -C ₆₀ carbocyclic group, C ₁ -C ₆₀ heterocyclic group, C ₆ -C ₆₀ aryl Oxy group, C ₆ -C ₆₀ arylthio group, -Si(Q ₁₁ )(Q ₁₂ )(Q ₁₃ ), -N(Q ₁₁ )(Q ₁₂ ), -B(Q ₁₁ )(Q ₁₂ ), - C(=O)(Q ₁₁ ), -S(=O) ₂ (Q ₁₁ ), -P(=O)(Q ₁₁ )(Q ₁₂ ), or unsubstituted or substituted with any combination thereof, C ₁ -C ₆₀ alkyl group, C ₂ -C ₆₀ alkenyl group, C ₂ -C ₆₀ alkynyl group, or C ₁ -C ₆₀ alkoxy group;

Deuterium, -F, -Cl, -Br, -I, hydroxyl group, cyano group, nitro group, C ₁ -C ₆₀ alkyl group, C ₂ -C ₆₀ alkenyl group, C ₂ -C ₆₀ alkynyl group, C ₁ - C ₆₀ alkoxy group, C ₃ -C ₆₀ carbocyclic group, C ₁ -C ₆₀ heterocyclic group, C ₆ -C ₆₀ aryloxy group, C ₆ -C ₆₀ arylthio group, —Si(Q ₂₁ )( Q ₂₂ )(Q ₂₃ ), -N(Q ₂₁ )(Q ₂₂ ), -B(Q ₂₁ )(Q ₂₂ ), -C(=O)(Q ₂₁ ), -S(=O) ₂ (Q ₂₁ ), -P(=O)(Q ₂₁ )(Q ₂₂ ), C ₃ -C ₆₀ carbocyclic group, C ₁ -C ₆₀ heterocyclic group, substituted or unsubstituted with any combination thereof, C ₆ -C ₆₀ aryloxy group, or C ₆ -C ₆₀ arylthio group; or

-Si(Q ₃₁ )(Q ₃₂ )(Q ₃₃ ), -N(Q ₃₁ )(Q ₃₂ ), -B(Q ₃₁ )(Q ₃₂ ), -C(=O)(Q ₃₁ ), -S (=O) ₂ (Q ₃₁ ), or -P(=O)(Q ₃₁ )(Q ₃₂ );

can be

In the present specification, Q ₁ to Q ₃ , Q ₁₁ to Q ₁₃ , Q ₂₁ to Q ₂₃ and Q ₃₁ to Q ₃₃ are each independently selected from hydrogen; heavy hydrogen; -F; -Cl; -Br; -I; hydroxyl group; cyano group; nitro group; C ₁ -C ₆₀ alkyl group; C ₂ -C ₆₀ alkenyl group; C ₂ -C ₆₀ alkynyl group; C ₁ -C ₆₀ alkoxy group; or a C ₃ -C ₆₀ carbocyclic group unsubstituted or substituted with deuterium, -F, a cyano group, a C ₁ -C ₆₀ alkyl group, a C ₁ -C ₆₀ alkoxy group, a phenyl group, a biphenyl group, or any combination thereof or a C ₁ -C ₆₀ heterocyclic group; it may be.

In the present specification, a hetero atom means any atom other than a carbon atom. Examples of the hetero atom include O, S, N, P, Si, B, Ge, Se, or any combination thereof.

In the present specification, "Ph" means a phenyl group, "Me" means a methyl group, "Et" means an ethyl group, "ter-Bu" or "But ^t " means a tert-butyl group, "OMe"" means a methoxy group.

In the present specification, "biphenyl group" means "a phenyl group substituted with a phenyl group". The "biphenyl group" belongs to a "substituted phenyl group" in which the substituent is a "C ₆ -C ₆₀ aryl group".

In the present specification, "terphenyl group" means "a phenyl group substituted with a biphenyl group". The "terphenyl group" belongs to a "substituted phenyl group" in which the substituent is a "C ₆ -C ₆₀ aryl group substituted with a C ₆ -C ₆₀ aryl group".

In the present specification, * and *', unless otherwise defined, refer to binding sites with neighboring atoms in the corresponding chemical formula.

Hereinafter, for example, a compound and a light emitting device according to an embodiment of the present invention will be described in more detail.

[Example]

(Evaluation of quantum efficiency before and after ligand exchange reaction of InGaP-ZnSe-ZnS quantum dots)

For the quantum dot dispersion ("Reference Example 1") containing InGaP-ZnSe-ZnS quantum dots, photoluminescence quantum efficiency (PLQY) was measured using Otsuka's QE-2100 equipment, and then the dispersion was purified once to remove impurities. After removal (“Reference Example 2”), photoluminescence quantum efficiency was measured in the same manner.

Thereafter, a polyethylene glycol (PEG) ligand was added to the quantum dot dispersion in which the quantum dots of InGaP-ZnSe-ZnS were dispersed, so that a part of the quantum dot surface of InGaP-ZnSe-ZnS was substituted with a PEG ligand PEG-modified quantum dots (“control group”). 1") was obtained, and Zn-PEG-modified quantum dots in which a part of the quantum dot surface of InGaP-ZnSe-ZnS were substituted with Zn-PEG ligands by adding Zn-PEG to the quantum dot dispersion in which other identical quantum dots were dispersed (“control group 2") was obtained.

For the control 1 and control 2, the photoluminescence quantum efficiency was measured using QE-2100 equipment.

The measured photoluminescence quantum efficiency is shown in FIG. 4 .

Referring to FIG. 4 , it was confirmed that the quantum efficiency was lowered in Reference Example 2 purified once compared to Reference Example 1, and a significant decrease in quantum efficiency of Control 1 in which the quantum dot surface was substituted with a PEG ligand was confirmed, Zn- In the case of Control 2 substituted with a PEG ligand, it can be confirmed that the quantum efficiency is significantly improved compared to Control 1. Control 2 is confirmed to have a quantum efficiency comparable to that of the quantum dots before the initial ligand substitution.

In the case of Reference Example 2, it is thought that some metals of the quantum dots are desorbed during the purification process and the quantum efficiency is reduced. It is thought that the quantum efficiency is significantly reduced. In contrast, in the case of Control 2, the quantum efficiency of the quantum dots was significantly increased by supplementing the transition metal (eg, Zn) removed in the ligand exchange reaction with the Zn metal of the Zn-PEG ligand, resulting in a substantial decrease in quantum efficiency. It was confirmed that the ligand exchange reaction was possible without

(Evaluation of compatibility by Zn-PEG ligand substitution)

For the previously prepared Control 1 and Control 2, a dispersibility test for hexanediol diacrylate (HDDA) was performed. Hexanediol diacrylate is a reactive diluent used in the quantum dot composition, and through a test on whether the quantum dot can maintain dispersibility with respect to HDDA, the light emitting performance after film formation can be confirmed.

In the experiment, 5 mL of HDDA was added to Controls 1 and 2 and left for 24 hours, and then dispersibility was visually confirmed. The results can be confirmed in FIG. 5, and it was confirmed that the control group 1 maintained dispersibility, but the control group 2 did not maintain the dispersibility.

In the case of Control 2, it is considered that the quantum dots were not dispersed by dissolving Zn-PEG with respect to HDDA.

(Calculation of the solubility of the ligand)

R _a of HDDA for m-PEG5-Zn, acryl-PEG5-Zn, crosslinkedPEG2-Zn, crosslinkedPEG3-Zn as an example of an oligomer or polymer containing a metal and a polar organic group introduced by a ligand exchange reaction on the surface of the quantum dot The values were calculated and are shown in Table 1 below. Here, the Ra value is calculated as a Hansen Solubility Parameter (HSP), and is defined by the following formula. When the value of Ra has a higher value based on HDDA, it means that the solubility is low and the dispersibility is higher.

R _a = (4x(δD _ligand -δD _HDDA ) ² +(δP _ligand -δP _HDDA ) ² +(δH _ligand -δH _HDDA ) ² ) ^1/2

δD _ligand represents the energy (unit: Mpa ^0.5 ) by the dispersion force between the ligand molecules;

δD _HDDA represents the energy due to HDDA intermolecular dispersion force;

δP _ligand represents energy due to dipolar intermolecular force between ligand molecules;

δP _HDDA represents energy due to dipolar intermolecular force between HDDA molecules;

δH _ligand represents the energy by hydrogen bonding between ligand molecules;

δH _HDDA represents energy due to hydrogen bonding between HDDA molecules.

δD δP δH δTot Ra reactive diluent HDDA 16.3 3.9 5.1 17.5 - ligand m-PEG5-Zn 16.4 7.6 8.3 19.9 4.9 acryl-PEG5-Zn 16.4 8.3 8.2 20.1 5.4 crosslinkedPEG2-Zn 15.8 10.2 9.9 21.3 8.0 crosslinkedPEG3-Zn 15.7 11.4 11.6 22.6 10.0

상기 표에서 보는 바와 같이 Ra 값은 아크릴기를 포함하는 acryl-PEG5-Zn의 경우 그렇지 않은 m-PEG5-Zn에 비해 높은 Ra값을 가졌다. 나아가, 가교기를 갖는 경우 HDDA에 대한 용해도가 더 낮아졌으며, 이는 증가된 Ra 값으로 확인된다.

As shown in the table above, the Ra value of acryl-PEG5-Zn containing an acryl group was higher than that of m-PEG5-Zn without it. Furthermore, when it has a crosslinking group, the solubility in HDDA is lower, which is confirmed by the increased Ra value.

Therefore, when the surface of the quantum dot is covered with cross-linked Zn-PEG, it is expected that it will be possible to prepare quantum dots with high compatibility due to the low solubility and high dispersibility resulting from the cross-linked Zn-PEG.

1: Quantum dots
11: core
12: shell
13: first area
14: outer layer
10: light emitting element
150: second electrode
110: first electrode
130: middle layer

Claims (20)

a core including a first semiconductor crystal;
a shell comprising one or more second semiconductor crystals disposed on the core;
a first region comprising a first ligand provided on the shell; and
an outer layer provided on the first region and comprising an oligomer or polymer comprising a metal and a polar organic group;
Including, quantum dots. According to claim 1,
The metal is Cd, Zn, Hg, Mg, Ga, Al, In, Sn, Pb, Si, Ge, Si, Ag, Cu, or a quantum dot comprising a combination thereof. According to claim 1,
The metal includes the same metal as the metal included in the second semiconductor crystal, quantum dots. According to claim 1,
The polar organic group comprises a hydroxyl group, a carbonyl group, an acryl group, an ester group, an ether group, a carboxyl group, an epoxy group, a halogen group, or a combination thereof, quantum dots. According to claim 1,
The oligomer or polymer is a quantum dot comprising a polymer of a monomer represented by the following formula (1):
<Formula 1>

In Formula 1,
M includes Cd, Zn, Hg, Mg, Ga, Al, In, Sn, Pb, Si, Ge, Si, Ag, Cu, or a combination thereof,
Y is selected from ionic groups,
A ₁ and A ₂ are each independently selected from a C ₁ -C ₂₀ alkylene group unsubstituted or substituted with at least one R _10a , and a C ₂ -C ₂₀ alkenylene group unsubstituted or substituted with at least one R _10a can be,
a1 and a2 are each independently an integer selected from 0 to 10,
When a1 is an integer of 2 or more, A ₁ of 2 or more are the same as or different from each other, and when a2 is an integer of 2 or more, A ₂ of 2 or more are the same or different from each other,
P ₁ and P ₂ are independently of each other *-O-*', *-S-*', *-C(=O)-*', *-S(=O) ₂ -*', *-C( =O)(O)-*', *-C(R ₁ )=C(R ₂ )-C(=O)OR ₃ -*', *-OC(=O)-C(R ₁ )=C (R ₂ )-*', *-C(R ₁ )(R ₂ )-*' is selected from;
b1 and b2 are each independently an integer selected from 1 to 10,
When b1 is an integer of 2 or more, P ₁ of 2 or more is the same as or different from each other, and when b2 is an integer of 2 or more, P ₂ of 2 or more are the same or different from each other,
c1 and c2 are integers selected from 0 to 10;
When c1 is an integer of 2 or more, *-(A ₁ ) _a1 -(P ₁ ) _b1 -*' of 2 or more are the same as or different from each other, and when c2 is an integer of 2 or more, 2 or more *-(A ₂ ) _a2 -(P ₂ ) _b2 -*' are the same as or different from each other,
R ₁ and R ₂ are each independently selected from hydrogen, a hydroxyl group, an alkoxy group, an epoxy group and a halogen group,
R _10a is selected from hydrogen, a C ₁ -C ₂₀ alkyl group, and a C ₁ -C ₂₀ alkenyl group,
n is an integer selected from 1 to 5,
2 or greater if n is an integer greater than or equal to 2

are the same or different from each other,
Z is a crosslinkable group including at least one of an ethylenically unsaturated group, an epoxy group, an alkoxy group, and an isocyanate group. 6. The method of claim 5,
The ionic group is a thiol group, a carboxyl group, an amine group, a phosphoric acid group, a sulfuric acid group, or a nitric acid group, quantum dots. 6. The method of claim 5,
The polymer comprises a cross-linked polymer linked by light, heat, or cross-linking by a cross-linking group of the cross-linkable group. According to claim 1,
The first ligand comprises a C ₁ -C ₂₀ hydrocarbon group, quantum dots. 9. The method of claim 8,
The first ligand further comprises an ionic group, quantum dots. According to claim 1,
The first ligand is a quantum dot coupled to the shell by a coordination bond. According to claim 1,
The first semiconductor and the second semiconductor may be each independently selected from a group III-VI semiconductor compound; group II-VI semiconductor compounds; III-V semiconductor compounds; III-VI semiconductor compounds; Group I-III-VI semiconductor compounds; group IV-VI semiconductor compounds; Group IV element or compound; or any combination thereof. According to claim 1,
The first semiconductor and the second semiconductor are independently of each other, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSTe, HgSe, ZnSTe, HgSe , HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, CdZnSeS, CdZnSeTe, CdZnSeTe, CdZnSSe, CdHSe;
GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP, InNP, InAlP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, InZnP, InGaZnP;
GaS, GaSe, Ga ₂ Se ₃ , GaTe, InS, InSe, In ₂ Se ₃ , InTe, InGaS ₃ , InGaSe _{3 ,}
AgInS, AgInS ₂ , CuInS, CuInS ₂ , CuGaO ₂ , AgGaO ₂ , AgAlO _{2 ;}
SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe
Si, Ge, SiC, SiGe;
or any combination thereof. According to claim 1,
The first semiconductor is GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InGaP , InAlP, InNP, InNAs, InNSb, InPAs, InPSb, InZnP, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb or any combination thereof, including,
The second semiconductor is CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgS, MgSe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeZnTe, ZnSTe, HgSeTe, HgST , CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnS, MgZnSe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, any combination of quantum dots including HgZnSe, HgZnSe, HgZnS. According to claim 1,
The shell is a double-layer shell including the first shell and the second shell,
A quantum dot provided with a first shell interposed between the core and the second shell. 15. The method of claim 14,
Wherein the first shell and the second shell include a second semiconductor crystal different from each other, quantum dots. 16. An ink composition comprising the quantum dots according to any one of claims 1 to 15. An optical member comprising the quantum dots according to any one of claims 1 to 15. 18. The method of claim 17,
The optical member is a color conversion member, an optical member. a first electrode;
a second electrode opposite the first electrode;
an intermediate layer interposed between the first electrode and the second electrode;
and a color conversion member provided on the outside of at least one of the first electrode and the second electrode, opposite the intermediate layer,
The electronic device, wherein the color conversion member includes the quantum dots according to any one of claims 1 to 15. 20. The method of claim 19,
Further comprising a thin film transistor,
The thin film transistor includes a source electrode and a drain electrode,
and a first electrode of the light emitting element is electrically connected to at least one of a source electrode and a drain electrode of the thin film transistor.

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