KR20210156731A - A semiconductor nanocrystal, a light-emitting film, production method of the light-emitting film, a light emitting device, and a display device - Google Patents

Abstract

The objective of the present invention is to provide a semiconductor nanocrystal capable of improving the efficiency and lifespan of a device and reducing a driving voltage by improving charge carrier mobility and a light-emitting film comprising the same. To this end, the present invention provides a semiconductor nanocrystal comprising an anion of an inorganic metal salt and a first organic ligand, which are bound to a surface thereof, wherein the first organic ligand includes a substituted or unsubstituted C6 to C30 aromatic ring group, a substituted or unsubstituted C3 to C30 aromatic heterocyclic group or a combination thereof, and a carboxylate group.

Description

A semiconductor nanocrystal, a light emitting film, a method of manufacturing a light emitting film, a light emitting element, and a display device

The present invention relates to a semiconductor nanocrystal, a light emitting film, a method for manufacturing a light emitting film, a light emitting device, and a display device.

Semiconductor nanocrystals (quantum dots) may have different energy band gaps by controlling the size and composition of the nanocrystals, and thus may emit light of various emission wavelengths. Semiconductor nanocrystals have a theoretical quantum yield (QY) of 100% and can emit light with high color purity, for example, light with a half maximum width of 40 nm or less. can

In the chemical wet method, an organic material such as a dispersant is coordinated on the surface of a semiconductor nanocrystal during crystal growth. As a result, semiconductor nanocrystals having a uniformly controlled size and exhibiting good light emitting properties and stability can be manufactured.

However, since these organic materials are insulating materials, the flow of electric charges such as electrons or holes may be hindered. Therefore, when semiconductor nanocrystals are applied to a device, the flow of charges is hindered, thereby reducing the efficiency or lifespan of the device and increasing the driving voltage.

One embodiment provides a semiconductor nanocrystal capable of improving the efficiency and lifespan of a device and reducing a driving voltage by improving charge mobility.

Another embodiment provides a light emitting film including the semiconductor nanocrystals.

Another embodiment provides a method of manufacturing the light emitting film.

Another embodiment provides a light emitting device including the light emitting film.

Another embodiment provides a display device including the light emitting device.

According to one embodiment, an anion of an inorganic metal salt and a first organic ligand are included on a surface, wherein the first organic ligand is a substituted or unsubstituted C6 to C30 aromatic ring group, or a substituted or unsubstituted C3 to C30 aromatic heterocyclic ring A semiconductor nanocrystal comprising a group, or a combination thereof, and a carboxylate group is provided.

The semiconductor nanocrystal may include a core including a first semiconductor nanocrystal and a shell including a second semiconductor nanocrystal disposed on the core and having a composition different from that of the first semiconductor nanocrystal.

The semiconductor nanocrystals may include InP, InZnP, ZnSe, ZnSeTe, or a combination thereof.

The semiconductor nanocrystal may include zinc and sulfur in an outermost layer.

The inorganic metal salt may include an inorganic metal halide, an inorganic metal sulfate, an inorganic metal nitrate, an inorganic metal thiocyanate, or a combination thereof.

The metal of the inorganic metal salt is zinc (Zn), indium (In), gallium (Ga), magnesium (Mg), lithium (Li), nickel (Ni), tin (Sn), copper (Cu), silver (Ag) , cobalt (Co), or a combination thereof.

The inorganic metal salt is zinc chloride, zinc bromide, zinc iodide, zinc nitrate, zinc sulfate, zinc thiocyanate, indium chloride, indium bromide, indium iodide, indium nitrate, indium sulfate, indium thiocyanate, gallium chloride. Gallium Bromide, Gallium Iodide, Gallium Nitrate, Gallium Sulphate, Gallium Thiocyanate, Magnesium Chloride, Magnesium Bromide, Magnesium Iodide, Magnesium Nitrate, Magnesium Sulfate, Magnesium Thiocyanate, Lithium Chloride, Lithium Bromide, Lithium Iodide, lithium nitrate, lithium sulfate, lithium thiocyanate, nickel chloride, nickel bromide, nickel iodide, nickel nitrate, nickel sulfate, nickel thiocyanate, tin chloride, tin bromide, tin iodide, tin nitrate, Tin sulfate, tin thiocyanate, copper chloride, copper bromide, copper iodide, copper nitrate, copper sulfate, copper thiocyanate, silver chloride, silver bromide, silver iodide, silver nitrate, silver sulfate, silver thiocyanate acid salts, cobalt chloride, cobalt bromide, cobalt iodide, cobalt nitrate, cobalt sulfate, cobalt thiocyanate, or combinations thereof.

The first organic ligand may be a compound represented by Formula 1 below.

[Formula 1]

In Formula 1, Ar ₁ is a substituted or unsubstituted monocyclic aromatic ring group, a substituted or unsubstituted condensed polycyclic aromatic ring group, or two or more A monocyclic aromatic ring group or two or more condensed polycyclic aromatic ring groups may be an aromatic ring group connected by a linker, wherein L is a single bond, a substituted or unsubstituted C1 to C30 alkylene group, or -CR ^a =CR ^b - or -C≡C- (wherein R ^a and R ^b are each independently hydrogen or a C1 to C10 alkyl group) an unsaturated linker, wherein X is a carboxylate group, and the Y is a hydroxyl group, a halogen group, an amine group, or a nitro group, and n is an integer of 0 to 6.

The aromatic ring group is benzene, biphenyl, naphthalene, anthracene, phenanthrene, pyrene, perylene, fluorene, pentalene, pyrazole, imidazole, thiazole, triazole, carbazole, pyridine, pyridazine , pyrimidine, pyrazine, triazine, indazole, indolizine, benzimidazole, benzthiazole, benzothiophene, benzopurine, isoquinoline, or purine.

The first organic ligand is benzoate, hydroxy benzoate, halo-benzoate, amino-benzoate, nitro-benzoate, 4- biphenyl carboxylate (4-biphenyl carboxylate), cinnamate, or a combination thereof.

The semiconductor nanocrystals are on the surface of the semiconductor nanocrystals, RCOOH, RNH ₂ , R ₂ NH, R ₃ N, RSH, RH ₂ PO, R ₂ HPO, R ₃ PO, RH ₂ P, R ₂ HP, R ₃ P, ROH, RCOOR', RPO(OH) ₂ , RHPOOH, or R ₂ POOH, wherein R and R' are each independently hydrogen, a C1-C40 substituted or unsubstituted aliphatic hydrocarbon, or a C6-C40 substituted or a second organic ligand comprising an anion of an unsubstituted aromatic hydrocarbon, or a combination thereof, wherein at least one R is not hydrogen in each ligand.

A weight ratio of the anion of the inorganic metal salt and the first organic ligand may be 30 to 60: 10 to 30.

A weight ratio of the second organic ligand, the anion of the inorganic metal salt, and the first organic ligand may be 30 to 60:30 to 60:10 to 30.

According to another embodiment, a light-emitting film including a plurality of the semiconductor nanocrystals is provided.

According to another embodiment, disposing a film including a plurality of semiconductor nanocrystals on a substrate, and treating the plurality of semiconductor nanocrystals with a solution containing an inorganic metal salt in a polar solvent to the plurality of semiconductor nanocrystals binding the anions of the inorganic metal salt, and treating the plurality of semiconductor nanocrystals with a solution containing a first organic ligand to bind the first organic ligand to the plurality of semiconductor nanocrystals, The first organic ligand includes a substituted or unsubstituted C6 to C30 aromatic ring group, a substituted or unsubstituted C3 to C30 aromatic heterocyclic group, or a combination thereof and a carboxylate group. .

According to another embodiment, there is provided a light emitting device including a first electrode and a second electrode facing each other, and the light emitting film disposed between the first electrode and the second electrode.

The light emitting device includes an electron injecting layer (EIL), an electron transporting layer (ETL), a hole blocking layer (HBL), or a combination thereof between the second electrode and the light emitting layer. It may further include an electron auxiliary layer selected from.

The electron auxiliary layer may include nanoparticles including zinc metal oxide.

The zinc metal oxide may be represented by Formula 2 below.

[Formula 2]

Zn _1-x M _x O

In Formula 2, M is Mg, Ca, Zr, W, Li, Ti, Y, Al, or a combination thereof, and 0 ≤ x ≤ 0.5.

Another embodiment provides a display device including the light emitting device.

The semiconductor nanocrystal according to the exemplary embodiment may improve charge mobility to improve device efficiency and lifespan, and reduce driving voltage.

The semiconductor nanocrystals are applied to light emitting devices (eg, electroluminescent devices, QD color converters), and various display devices (eg, QD-LEDs), biological labeling (biosensors, bio-imaging), photodetectors, solar cells (eg, , QD optoelectronic devices), polymer composites, or organic-inorganic hybrid composites.

1 is a diagram schematically illustrating a semiconductor nanocrystal according to an embodiment.
2 is a schematic cross-sectional view of an example of a light emitting device according to another embodiment.
3 is a schematic cross-sectional view of another example of a light emitting device according to another embodiment.
4 is a schematic cross-sectional view of another example of a light emitting device according to another embodiment.
5 is a cross-sectional view illustrating a display device according to another exemplary embodiment.
6 and 7 are graphs showing the evaluation results of electron transport (ET) characteristics in Experimental Example 1.
8 and 9 are graphs showing the evaluation results of photoluminescence of the light emitting film in Experimental Example 2;
10 and 11 are graphs showing the hole and electron transport capability evaluation results of the light emitting device in Experimental Example 3;

Advantages and features of the techniques described hereinafter, and methods of achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the implemented form may not be limited to the embodiments disclosed below. Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with meanings commonly understood by those of ordinary skill in the art. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular. In the entire specification, when a part "includes" a certain component, this means that other components may be further included, rather than excluding other components, unless otherwise stated.

The singular also includes the plural, unless the phrase specifically dictates otherwise.

In order to clearly express various layers and regions in the drawings, the thicknesses are enlarged. Throughout the specification, like reference numerals are assigned to similar parts.

When a part, such as a layer, film, region, plate, etc., is said to be “on” another part, it includes not only cases where it is “directly on” another part, but also cases where there is another part in between. Conversely, when we say that a part is "just above" another part, we mean that there is no other part in the middle.

Unless otherwise defined below, "substitution" means that, instead of hydrogen, a compound or a corresponding moiety is a C1 to C30 alkyl group, a C2 to C30 alkynyl group, a C6 to C30 aryl group, a C7 to C30 alkylaryl group , C1 to C30 alkoxy group, C1 to C30 heteroalkyl group, C3 to C30 heteroalkylaryl group, C3 to C30 cycloalkyl group, C3 to C15 cycloalkenyl group, C6 to C30 cycloalkynyl group, C2 to C30 of heterocycloalkyl group, halogen (-F, -Cl, -Br or -I), hydroxyl group (-OH), nitro group (-NO ₂ ), cyano group (-CN), amino group (-NRR' where R and R ' is independently of each other hydrogen or a C1 to C6 alkyl group), an azido group (-N ₃ ), an amidino group (-C(=NH)NH ₂ )), a hydrazino group (-NHNH ₂ ), a hydrazono group ( =N(NH ₂ )), aldehyde group (-C(=O)H), carbamoyl group (-C(O)NH ₂ ), thiol group (-SH), ester group (-C(=O) )OR, where R is a C1 to C6 alkyl group or a C6 to C12 aryl group), a carboxyl group (-COOH) or a salt thereof (-C(=O)OM, where M is an organic or inorganic cation), a sulfonic acid group (- SO ₃ H) or a salt thereof (-SO ₃ M, where M is an organic or inorganic cation), a phosphoric acid group (-PO ₃ H ₂ ) or a salt thereof (-PO ₃ MH or -PO ₃ M ₂ , where M is an organic or inorganic cation) and a combination thereof means substituted with a substituent.

As used herein, the term "monocyclic aromatic ring group" refers to a cyclic group providing a conjugated structure (eg, a C6 to C12 aryl group or a C6 to C8 aryl group) or a heterocyclic group providing a conjugated structure (eg, C2 to C12 heteroaryl group or C2 to C4 heteroaryl group).

As used herein, the term "condensed polycyclic aromatic ring group" is a ring group formed by fusion of two or more monocyclic aromatic ring groups with each other, and a C8 to C20 aryl group, for example, a C8 to C15 aryl group or C4 to C20 hetero It means an aryl group, for example, a C4 to C15 heteroaryl group.

As used herein, the term “hetero” refers to including 1 to 3 heteroatoms that may be N, O, S, Si, P, or a combination thereof.

Here, the term “group” refers to a group on the periodic table.

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

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

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

"Group I" may include Groups IA and IB, including but not limited to Li, Na, K, Rb, Cs.

“Group V” includes Group VA and includes, but is not limited to, nitrogen, phosphorus, arsenic, antimony, and bismuth.

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

Semiconductor nanocrystals (hereinafter, also referred to as “quantum dots (QDs)”) may absorb light from an excitation source and emit light corresponding to its energy bandgap. For example, a semiconductor nanocrystal may have a narrow energy bandgap and an emission wavelength may increase as the particle size increases. Since semiconductor nanocrystals have advantages such as high quantum yield, high color purity, high stability, and spectral tenability, they are attracting attention as light emitting materials in various fields such as display devices, energy devices, or bioluminescent devices. .

A semiconductor nanocrystal light emitting device (QD-LED) is a self-luminous device using a semiconductor nanocrystal with high quantum efficiency as a light emitting center of the light emitting layer. When light emission occurs in semiconductor nanocrystals, which are inorganic semiconductors, compared to organic light emitters, there is an advantage in that it is possible to develop a self-luminous LED having a very narrow emission spectrum with high efficiency.

QD-LED has a structure similar to OLED and is a light emitting diode using inorganic QD instead of organic material as the light emitting layer. The basic operating principle is the same as that of OLED. However, in order to drive the QD-LED with high efficiency, high luminance, and long lifespan, not only the number of holes and electrons entering the light emitting layer are increased, but also the quantitative balance between the two carriers is very important. It is important.

To this end, the barrier injected into the semiconductor nanocrystals from the hole transporting layer (HTL) should be low, and similarly, the barriers injected into the semiconductor nanocrystals from the electron transporting layer (ETL) should be low.

To this end, in the case of the hole side, efforts are being made to develop an HTL material with high hole mobility or to match the HOMO level of the HTL layer with the semiconductor nanocrystal. On the other hand, in the case of the former, in order to control the conductivity of the ETL layer, metal doping or an additive is mixed to improve and/or control the conductivity of the ETL layer.

According to one embodiment, an anion of an inorganic metal salt and a first organic ligand are included on a surface, wherein the first organic ligand is a substituted or unsubstituted C6 to C30 aromatic ring group, or a substituted or unsubstituted C3 to C30 aromatic heterocyclic ring A semiconductor nanocrystal comprising a carboxylate group with a group, or a combination thereof, is provided.

That is, in the semiconductor nanocrystal, the surface ligand of the semiconductor nanocrystal is mixed and substituted with an anion of an inorganic metal salt and a first organic ligand, and the conduction property of the light emitting film including the semiconductor nanocrystal is controlled to improve device properties and improve lifespan A light emitting device can be provided.

The semiconductor nanocrystal is a group II-VI compound, a group III-V compound, a group IV-VI compound, a group IV element or compound, a group I-III-VI compound, a group I-II-IV-VI compound, or these may include a combination of

The group II-VI compound is a binary compound selected from ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and mixtures thereof; ternary compounds selected from ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS and mixtures thereof; and HgZnTeS, HgZnSeS, HgZnSeTe, HgZnSTe, and mixtures thereof. The group II-VI compound may further include a group III metal.

The group III-V compound is a binary compound selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; a ternary compound selected from GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb and mixtures thereof; and GaAlNPs, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof. The group III-V compound may further include a group ± element. An example of such a semiconductor nanocrystal is InZnP.

The group IV-VI compound is a diatomic compound selected from SnS, SnSe, SnTe, and mixtures thereof; ternary compounds selected from SnSeS, SnSeTe, SnSTe, and mixtures thereof; and quaternary compounds such as SnSSeTe.

Examples of the group I-III-VI compound include, but are not limited to, _{CuInSe 2} , CuInS _{2 , CuInGaSe, and CuInGaS.}

Examples of the group I-II-IV-VI compound include, but are not limited to, CuZnSnSe and CuZnSnS.

The group IV element or compound is a single element compound selected from Si, Ge, and mixtures thereof; and a binary compound selected from SiC, SiGe, and mixtures thereof.

The binary, ternary, or quaternary compound may be present in the particle at a uniform concentration, or may be present in the same particle because the concentration distribution is partially different. The semiconductor nanocrystal comprises a core comprising a first semiconductor nanocrystal and a shell comprising a second semiconductor nanocrystal disposed on at least a portion (eg, all of the surface) of a surface of the core and having a composition different from that of the first semiconductor nanocrystal; can have An alloyed layer may or may not be present at the interface between the core and the shell. The alloying layer may be a homogeneous alloy or may be a gradient alloy. In the gradient alloy, the concentration of elements present in the shell may have a concentration gradient that changes in the radial direction (eg, decreases or increases toward the center). In addition, the shell may be a multi-layered shell including two or more layers, and the two adjacent layers have different compositions. In a multilayer shell, one or more layers, independently of each other, may comprise semiconductor nanocrystals of a single composition. In a multi-layer shell, one or more layers may include, independently of each other, alloyed semiconductor nanocrystals. In a multilayer shell, one or more layers may have a radially varying concentration gradient in the composition of the semiconductor nanocrystals.

In the semiconductor nanocrystal of the core-shell structure, the bandgap energy of the shell material may be greater than that of the core material, but is not limited thereto. The bandgap energy of the shell material may be smaller than that of the core material. In the case of a multilayer shell, the outermost layer material may have a larger energy bandgap than the material of the core and inner layers of the shell (ie, layers closer to the core). In the multilayer shell, the bandgap of the semiconductor nanocrystals in each layer can be appropriately selected to efficiently exhibit the quantum confinement effect.

For example, the semiconductor nanocrystals may include indium, zinc, or a combination thereof. The semiconductor nanocrystals may include InP, InZnP, ZnSe, ZnSeTe, or a combination thereof. The semiconductor nanocrystals may include zinc and sulfur in the outermost layer of the shell.

The emission wavelength of the semiconductor nanocrystal can be appropriately selected. For example, the maximum photoluminescence peak of the semiconductor nanocrystal may exist in a wavelength range from an ultraviolet region to a near-infrared region. The maximum photoluminescence peak wavelength of the semiconductor nanocrystal may be in the range of 420 nm to 750 nm (460 nm to 700 nm). In the case of a green light emitting semiconductor nanocrystal, it may exhibit a maximum emission peak wavelength within a range of 500 nm (eg, 510 nm) to 550 nm. In the case of a red light-emitting semiconductor nanocrystal, it may exhibit a maximum emission peak wavelength within a range of 600 nm (eg, 610 nm) to 650 nm. In the case of a blue light emitting semiconductor nanocrystal, it may exhibit a maximum emission peak wavelength within the range of 440 nm (eg, 450 nm) to 470 nm (eg, 480 nm).

The semiconductor nanocrystal may exhibit a photoluminescence spectrum having a relatively narrow full width at half maximum. In one example, the semiconductor nanocrystals, in their photoluminescence spectrum, about 45 nm or less, for example, about 44 nm or less, about 43 nm or less, about 42 nm or less, about 41 nm or less, about 40 nm or less, about 39 nm or less It may have a full width at half maximum of about 38 nm or less, about 37 nm or less, about 36 nm or less, or about 35 nm or less. The semiconductor nanocrystals are about 10% or more, such as about 20% or more, about 30% or more, about 40% or more, about 50% or more, about 60% or more, about 70% or more, about 80% or more, about 90% or more. It can have a quantum yield of more than, or even about 100%.

The semiconductor nanocrystals may have a size of about 1 nm or more and about 100 nm or less (eg, a particle diameter or a particle diameter calculated from a two-dimensional area confirmed by electron microscopic analysis in the case of non-spherical particles). For example, the semiconductor nanocrystals may have a size of about 1 nm to about 50 nm, for example, 2 nm (or 3 nm) to 35 nm. For example, the size of the semiconductor nanocrystals is about 1 nm or more, about 2 nm or more, about 3 nm or more, about 4 nm or more, about 5 nm or more, 6 nm or more, 7 nm or more, 8 nm or more, 9 nm or more , or 10 nm or more. For example, the size of the semiconductor nanocrystals is about 50 nm or less, about 40 nm or less, about 30 nm or less, about 25 nm or less, about 20 nm or less, about 19 nm or less, about 18 nm or less, about 17 nm or less, It can be about 16 nm or less, or about 15 nm or less.

The semiconductor nanocrystals may have any shape. For example, the shape of the semiconductor nanocrystal is a sphere, a polyhedron, a pyramid, a multi-pod, a cube, a nanotube, a nanowire, a nanofiber, a nanosheet, a nanoplate, or a combination thereof. may include

The semiconductor nanocrystals may be synthesized by any method. For example, semiconductor nanocrystals having a size of several nanometers may be synthesized through a wet chemical process. In the chemical wet method, crystal grains are grown by reacting precursor materials in an organic solvent, and the organic solvent or the second organic ligand compound is coordinated to the surface of the semiconductor nanocrystal to control the crystal growth.

The organic solvent and the second organic ligand compound may be appropriately selected.

The organic solvent is a C6 to C22 primary amine such as hexadecylamine, a C6 to C22 secondary amine such as dioctylamine, a C6 to C40 tertiary amine such as trioctylamine, a nitrogen-containing heterogeneous amine such as pyridine Cyclic compounds, C6 to C40 olefins such as octadecene, C6 to C40 aliphatic hydrocarbons such as hexadecane, octadecane, and squalane, C6 to C30 alkyl groups such as phenyldodecane, phenyltetradecane, and phenylhexadecane substituted aromatic hydrocarbons, primary, secondary, or tertiary phosphines (eg, trioctylphosphine) substituted with at least one (eg, 1, 2, or 3) C6 to C22 alkyl groups, such as , C12 to C22 aromatic ethers such as phosphine oxide (eg trioctylphosphine oxide) substituted with 1, 2, or 3 C6 to C22 alkyl groups, phenyl ether, benzyl ether, or a combination thereof can

The second organic ligand compound is RCOOH, RNH ₂ , R ₂ NH, R ₃ N, RSH, RH ₂ PO, R ₂ HPO, R ₃ PO, RH ₂ P, R ₂ HP, R ₃ P, ROH, RCOOR ', RPO(OH) ₂ , RHPOOH, or R ₂ POOH, wherein R and R' are each independently hydrogen, a C1 to C40 substituted or unsubstituted aliphatic hydrocarbon, or a C6 to C40 substituted or unsubstituted aromatic hydrocarbon , or combinations thereof, wherein at least one R in each ligand is not hydrogen. The second organic ligand may include an anion of the second organic ligand compound. For example, when the second organic ligand compound is oleic acid, the second organic ligand may be oleate.

The prepared semiconductor nanocrystals may be recovered by pouring into an excess of non-solvent to remove excess organic matter not coordinated on the surface, and centrifuging the resulting mixture. Specific types of the non-solvent include, but are not limited to, acetone, ethanol, and methanol.

The recovered semiconductor nanocrystals include an organic material (eg, a second organic ligand) bound to a surface, and the amount of the organic material may be generally 20% by weight or more and 35% by weight or less based on the total weight of the semiconductor nanocrystals. For the dispersibility of the semiconductor nanocrystals, the presence of an organic material in the above-described content may be required. However, according to the research of the present inventors, since the above-mentioned organic material actually acts as a barrier for electron and hole injection, it can bring about a significant decrease in luminous efficiency.

Accordingly, the semiconductor nanocrystal includes an anion of an inorganic metal salt on the surface of the semiconductor nanocrystal. For example, the anion of the inorganic metal salt may be bound to the semiconductor nanocrystal as an inorganic metal salt itself, or only the anion of the inorganic metal salt may be bound to the semiconductor nanocrystal.

The anion of the inorganic metal salt may be strongly bound to the surface of the semiconductor nanocrystals and instead of (eg, replacing) the second organic ligand (eg, oleate) originally present on the surface of the semiconductor nanocrystals. can passivate them. While not wishing to be bound by a particular theory, the semiconductor nanocrystals may include an anion of an inorganic metal salt strongly bound to the surface instead of at least a portion of the second organic ligand serving as an insulator, and the anion of the inorganic metal salt is the semiconductor nanocrystal. It is thought that it is possible to provide improved passivation to the crystal, to improve the charge injection characteristics for the semiconductor nanocrystal, and to lower the driving voltage of the device.

The inorganic metal salt may be in the form of an inorganic metal halide, an inorganic metal sulfate, an inorganic metal nitrate, an inorganic metal thiocyanate, or a combination thereof, and the metal of the inorganic metal salt is zinc (Zn), indium (In), gallium ( Ga), magnesium (Mg), lithium (Li), nickel (Ni), tin (Sn), copper (Cu), silver (Ag), cobalt (Co), or a combination thereof.

For example, the inorganic metal salt is zinc chloride, zinc bromide, zinc iodide, zinc nitrate, zinc sulfate, zinc thiocyanate, indium chloride, indium bromide, indium iodide, indium nitrate, indium sulfate, indium thiocyanate. Acid salt, gallium chloride, gallium bromide, gallium iodide, gallium nitrate, gallium sulfate, gallium thiocyanate, magnesium chloride, magnesium bromide, magnesium iodide, magnesium nitrate, magnesium sulfate, magnesium thiocyanate, lithium chloride, lithium Bromide, lithium iodide, lithium nitrate, lithium sulfate, lithium thiocyanate, nickel chloride, nickel bromide, nickel iodide, nickel nitrate, nickel sulfate, nickel thiocyanate, tin chloride, tin bromide, tin iodide , tin nitrate, tin sulfate, tin thiocyanate, copper chloride, copper bromide, copper iodide, copper nitrate, copper sulfate, copper thiocyanate, silver chloride, silver bromide, silver iodide, silver nitrate, silver sulfate , silver thiocyanate, cobalt chloride, cobalt bromide, cobalt iodide, cobalt nitrate, cobalt sulfate, cobalt thiocyanate, or combinations thereof.

For example, the metal included in the inorganic metal salt may be the same as the metal included in the outermost layer of the semiconductor nanocrystal. The outermost layer of the semiconductor nanocrystal may include zinc, and the inorganic metal salt may be a zinc halide.

On the other hand, as described above, in the case of the second organic ligand (eg, oleate, C18) present on the surface of the semiconductor nanocrystal after synthesis, the amount of organic material in the light emitting film including the semiconductor nanocrystal is increased and the insulating property is improved. This prevents current injection. Therefore, a semiconductor nanocrystal in which the amount of organic matter is reduced through anion substitution of the inorganic metal salt is used. However, when the organic material content is reduced, there must be no decrease in the photoluminescence quantum yield (PLQY) of the semiconductor nanocrystals, and if an excess is substituted, the semiconductor nanocrystals may be precipitated. However, when only the anion of the inorganic metal salt is substituted, the problem of further improving PLQY while reducing the content of the insulator organic material and preventing the semiconductor nanocrystal from precipitating at the same time is not solved. In particular, in the case of a blue light emitting device based on a cadmium-free ZnSe core, the overall band level is higher than that of a cadmium-based semiconductor nanocrystal (HOMO ~ -5.8 eV, LUMO ~ -3.1 eV), When a metal oxide (eg, zinc magnesium oxide) is used for the ETL layer (CB (conduction band) ~ -4.3 eV), the electron block becomes severe.

In addition, even when the second organic ligand is substituted with a short organic ligand (eg, dodecanethiol (DDT) or zinc-dodecanthiol (ZnDDT)) or substituted with an anion of the inorganic metal salt alone, electron transport (ET) characteristics This does not improve.

In the semiconductor nanocrystal according to an embodiment, the surface second organic ligand of the semiconductor nanocrystal is replaced with the anion of the inorganic metal salt and the first organic ligand to improve ET, increase PLQY and thermal stability, and improve actual device performance You can even get the results you want.

That is, by coordinating the first organic ligand including an aromatic ring group, an aromatic heterocyclic group, or a combination thereof, having a conjugated structure capable of moving electrons or holes well to the surface of the semiconductor nanocrystal, flow can be improved.

The first organic ligand includes a substituted or unsubstituted C6 to C30 aromatic ring group, a substituted or unsubstituted C3 to C30 aromatic heterocyclic group, or a combination thereof and a carboxylate group.

As an example, the first organic ligand may be represented by Formula 1 below.

[Formula 1]

In Formula 1, Ar ₁ is a substituted or unsubstituted monocyclic aromatic ring group, a substituted or unsubstituted condensed polycyclic aromatic ring group, or two or more It may be an aromatic ring group in which a monocyclic aromatic ring group or two or more condensed polycyclic aromatic ring groups are connected by a linker.

The linker is a single bond, -(CR ^a R ^b ) _n1 -, -O-, -S-, -Se-, -C(=O)-, -C(=O)O-, -OC(=O )-, -N=, -NR ^c -, -SiR ^d R ^e - and -GeR ^f R ^g - may be selected from, and R ^a to R ^g are each independently hydrogen, substituted or unsubstituted C1 to a C30 alkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C3 to C30 heteroaryl group, a substituted or unsubstituted C1 to C6 alkoxy group, a halogen group or a cyano group.

For example, Ar ₁ may be a substituted or unsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2 to C20 heteroaryl group. For example, Ar ₁ is benzene, biphenyl, naphthalene, anthracene, phenanthrene, pyrene, perylene, fluorene, pentalene, pyrazole, imidazole, thiazole, triazole, carbazole, pyridine , pyridazine, pyrimidine, pyrazine, triazine, indazole, indolizine, benzimidazole, benzthiazole, benzothiophene, benzopurine, isoquinoline or purine.

L is a single bond, a substituted or unsubstituted C1 to C30 alkylene group, or -CR ^a =CR ^b - or -C≡C- (wherein R ^a and R ^b are each independently hydrogen, or C1 to C10 of an alkyl group) may be an unsaturated linker.

Wherein X is a carboxylate group bonded to the surface of the semiconductor nanocrystal, Y is a hydroxyl group, a halogen group, an amine group, or a nitro group, and n may be an integer of 0 to 6.

For example, the first organic ligand may be benzoate, hydroxy benzoate, halo-benzoate, amino-benzoate, or nitro-benzoate. , 4-biphenyl carboxylate, cinnamate, or a combination thereof.

The first organic ligand including the aromatic ring group or the aromatic heterocyclic group can improve the current injection characteristics and lifespan of the semiconductor nanocrystal, improve electron and hole mobility, and lower the resistance to increase the driving voltage of the device. can be lowered, and the efficiency and lifespan can be greatly improved.

The semiconductor nanocrystal may further include a carboxylate group on its surface. The carboxylate group may be the second organic ligand originally present on the surface of the semiconductor nanocrystals. The carboxylate group may include an anion of an aliphatic carboxylic acid compound of C6 or higher, such as C8 or higher, C12 or higher, C15 or higher, C16 or higher, or C18 or higher and C30 or lower. The plurality of semiconductor nanocrystals may include a ligand derived from a compound represented by RCOOH (wherein R is an alkyl group of C12 or more or an alkenyl group of C12 or more) in a limited amount.

The second organic ligand may be derived from a second organic ligand compound. Specific examples of the second organic ligand compound include thiol compounds such as methane thiol, ethane thiol, propane thiol, butane thiol, pentane thiol, hexane thiol, octane thiol, dodecane thiol, hexadecane thiol, octadecane thiol, and benzyl thiol ; Methanamine, Ethanamine, Propanamine, Butanamine, Pentylamine, Hexylamine, Octylamine, Nonylamine, Decylamine, Dodecylamine, Hexadecylamine, Octadecylamine, Dimethylamine, Diethylamine, Dipropylamine, amines such as tributylamine and trioctylamine; carboxylic acid compounds such as methanic acid, ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, dodecanoic acid, hexadecanoic acid, octadecanoic acid, oleic acid, and benzoic acid; phosphine compounds such as methyl phosphine, ethyl phosphine, propyl phosphine, butyl phosphine, pentyl phosphine, octylphosphine, dioctyl phosphine, tributyl phosphine, trioctylphosphine, and the like; Phosphines such as methyl phosphine oxide, ethyl phosphine oxide, propyl phosphine oxide, butyl phosphine oxide, pentyl phosphine oxide, tributyl phosphine oxide, octyl phosphine oxide, dioctyl phosphine oxide, trioctyl phosphine oxide, etc. compound or an oxide compound thereof; diphenyl phosphine, triphenyl phosphine compound or oxide compound thereof; hexylphosphinic acid, octylphosphinic acid, dodecanephosphinic acid, tetradecanephosphinic acid, hexadecanephosphinic acid, octadecanephosphinic acid, etc. C5-C20 alkyl C5-C20 alkyl phosphonic acids; and the like, but is not limited thereto.

The weight ratio of the anion of the inorganic metal salt and the first organic ligand may be 30 to 60: 10 to 30, for example, the weight ratio of the anion of the inorganic metal salt to 30: 10 to 30, 35: 10 to 30, 40: 10 to 30, 45: 10 to 30, 50: 10 to 30, 55: 10 to 30, or 60: 10 to 30, for example, the weight ratio of the first organic ligand is 30 to 60: 10, 30 to 60:15, 30 to 60:20, 30 to 60:25, or 30 to 60:30.

The weight ratio of the second organic ligand, the anion of the inorganic metal salt, and the first organic ligand may be 30 to 60: 30 to 60: 10 to 30, for example, the weight ratio of the second organic ligand to 30: 30 to 60: 10 to 30, 35: 30 to 60: 10 to 30, 40: 30 to 60: 10 to 30, 45: 30 to 60: 10 to 30, 50: 30 to 60: 10 to 30, 55: 30 to 60: 10 to 30, or 60: 30 to 60: 10 to 30, for example, the weight ratio of the anion of the inorganic metal salt is 30 to 60: 30: 10 to 30, 30 to 60: 35: 10 to 30, 30 to 60: 40: 10 to 30, 30 to 60: 45: 10 to 30, 30 to 60: 50: 10 to 30, 30 to 60: 55: 10 to 30, 30 to 60: 60: 10 to 30, for example, the weight ratio of the first organic ligand is 30 to 60: 30 to 60: 10, 30 to 60: 30 to 60: 15, 30 to 60: 30 to 60: 20, 30 to 60: 30 to 60: 25, or 30 to 60: 30 to 60: 30.

1 is a diagram schematically illustrating a semiconductor nanocrystal according to an embodiment. 1 shows that the semiconductor nanocrystal contains zinc as an outermost layer, chloride as an anion of the inorganic metal salt, benzoate as the first organic ligand, and oleate as the second organic ligand. This is an example of a case where

Referring to FIG. 1 , the anion of the inorganic metal salt and the first organic ligand substitute for the second organic ligand originally present on the surface of the semiconductor nanocrystal, ^{and combine with Zn +} on the surface of the semiconductor nanocrystal to form the semiconductor The nanocrystals are passivated.

The light emitting film according to another embodiment includes a plurality of the above-described semiconductor nanocrystals.

The light emitting layer may be disposed on a substrate. The light emitting layer may be in contact with the substrate. The substrate may include a hole auxiliary layer (eg, a hole injection layer, a hole transport layer, or a combination thereof) or an electron auxiliary layer (eg, an electron injection layer, an electron transport layer, or a combination thereof) in a light emitting device to be described later. . The substrate may be a light-transmitting or transparent substrate.

The thickness of the light emitting film is 5 nm or more, for example, 6 nm or more, 7 nm or more, 8 nm or more, 9 nm or more, 10 nm or more, 11 nm or more, 12 nm or more, 13 nm or more, 14 nm or more, 15 nm or more, 16 nm or more, 17 nm or more, 18 nm or more, 19 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, or 35 nm or more. The light emitting film may include two or more monolayers of semiconductor nanocrystals, for example, three or more layers, or four or more layers. The thickness of the emission layer may be 100 nm or less, for example, 90 nm or less, 80 nm or less, 70 nm or less, 60 nm or less, 50 nm or less, or 40 nm or less. The light emitting layer according to an exemplary embodiment may exhibit improved charge injection characteristics, and thus may have a relatively increased thickness.

Another embodiment relates to the above-described method for manufacturing the light emitting film, the method comprising disposing a film including a plurality of semiconductor nanocrystals on a substrate, and a solution containing an inorganic metal salt in a polar solvent to the plurality of semiconductor nanocrystals processing the crystals to bind the anions of the inorganic metal salt to the plurality of semiconductor nanocrystals; binding the first organic ligand.

The semiconductor nanocrystal, the anion of the inorganic metal salt, the first organic ligand, or the substrate are the same as described above.

The binding of the anion of the inorganic metal salt and/or the first organic ligand to the plurality of semiconductor nanocrystals may be performed before and/or after forming the layer.

Before treatment with the solution, the plurality of semiconductor nanocrystals may include a native ligand on the surface. The native ligand may include the above-described second organic ligand (eg, carboxylate).

A method of disposing the plurality of semiconductor nanocrystals on the substrate is not particularly limited and may be appropriately selected. The arrangement method may include spin coating, contact printing, or a combination thereof. The specific manner of the arrangement can be appropriately selected.

The method may further include washing the treated film at least once with a polar solvent not containing the inorganic metal salt. In the cleaning step, the inorganic metal salt not bound to the plurality of semiconductor nanocrystals may be removed.

The disposed (and optionally cleaned) luminescent film is at least 50°C, such as at least 60°C, at least 70°C, or at least 75°C and at most 150°C, such as at or below 120°C, or at most 100°C. It may be heat-treated at a temperature of 1 minute or more, for example, 2 minutes or more, 3 minutes or more, 4 minutes or more, 5 minutes or more, 10 minutes or more, 15 minutes or more, or 20 minutes or more and 1 hour or less.

The polar solvent may include an alcohol having a C1 to C10 straight-chain or branched hydrocarbon group, or a combination thereof. For example, the polar solvent may include methanol, ethanol, propanol, isopropanol, butanol, pentanol, hexanol, heptanol, or a combination thereof.

The treatment may include contacting the solution with the membrane. The contacting may include, but is not limited to, spraying, dipping, or a combination thereof.

Another embodiment provides a light emitting device including the above-described light emitting film.

In the light emitting device, the light emitting film is disposed between two electrodes facing each other, for example, a first electrode and a second electrode (or an anode and a cathode).

For example, at least one of the anode and the cathode may include a metal oxide-based transparent electrode (eg, ITO). At least one of the anode and the cathode may include a metal (eg, Mg, Al, etc.) having a predetermined (eg, relatively low) work function. For example, TFB and/or PVK may be disposed as a hole transport layer, and/or PEDOT:PSS and/or a p-type metal oxide or the like may be disposed between the electrode and the light emitting layer as a hole injection (transport) layer. In addition, an electron auxiliary layer (eg, an electron transport layer, etc.) may be disposed between the light emitting film and the cathode (see FIG. 2 ).

In another embodiment, the light emitting device may have an inverted structure. Here, the cathode disposed on the transparent substrate may include a metal oxide-based transparent electrode (eg, ITO, FTO), and the anode has a predetermined (eg, relatively high) work function of a metal (Au, Ag) may include For example, an n-type metal oxide (ZnO) or the like may be disposed between the cathode and the light emitting layer as an electron auxiliary layer (eg, an electron transport layer). Between the metal anode and the semiconductor nanocrystal light emitting film, a hole auxiliary layer (eg, a hole transport layer including TFB and/or PVK and/or _{a hole injection layer including MoO 3} or other p-type metal oxide) may be disposed ( See Fig. 3).

Hereinafter, the light emitting element and a display device including the same will be described in detail with reference to FIGS. 4 and 5 . 4 is a cross-sectional view of a light emitting device according to an exemplary embodiment, and FIG. 5 is a cross-sectional view illustrating a display device according to an exemplary embodiment.

Although the structure of the display device 200 shown in FIG. 5 is described with a driving thin film transistor and a light emitting element, the structure of the display device 200 may include a switching thin film transistor, a signal line, and the like.

Referring to FIG. 4 , a light emitting device 100 according to a non-limiting embodiment includes a first electrode 160 , a hole auxiliary layer 172 , a light emitting layer 173 , and an electron auxiliary (eg, transport) layer 174 . ) and the second electrode 180 are sequentially stacked. The light emitting device layer 170 of FIG. 4 to be described later includes a hole auxiliary layer 172 , a light emitting layer 173 , and an electron transport layer 174 .

When the first electrode 160 is an anode, it may include a material having a high work function to facilitate hole injection.

According to a non-limiting embodiment, the first electrode 160 is a transparent electrode, indium tin oxide (ITO), indium zinc oxide (IZO), zinc tin oxide (ZTO), copper indium oxide (CIO), copper zinc oxide Conductive oxides, such as (CZO), gallium zinc oxide (GZO), aluminum zinc oxide (AZO), tin oxide (SnO ₂ ), zinc oxide (ZnO), or combinations thereof, calcium (Ca), ytterbium (Yb), aluminum A metal such as (Al), silver (Ag), or magnesium (Mg), a conductive carbon such as graphene or carbon nanotubes, or a conductive polymer such as PEDOT:PSS may be used, for example, to have a thin thickness.

In addition, the first electrode 160 is not limited thereto, and may be formed in a stacked structure of two or more layers.

The hole auxiliary layer 172 may be positioned between the first electrode 160 and the emission layer 173 . In this case, the hole auxiliary layer 172 may be a hole injection layer that facilitates injection of holes from the first electrode 160 into the emission layer 173 and/or a hole transport layer that facilitates transport of holes.

In addition, the hole auxiliary layer 172 may further include an electron blocking layer for blocking the movement of electrons, a hole blocking layer for blocking the movement of holes, or a combination thereof.

The hole transport layer and/or the hole injection layer may be, for example, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), PEDOT:PSS), poly (9,9-dioctyl-fluorene-co-N-(4-butylphenyl)-diphenylamine) (Poly(9,9-dioctyl-fluorene-co-N-(4-butylphenyl)-diphenylamine), TFB), polyarylamine, poly(N-vinylcarbazole) (poly(N-vinylcarbazole, PVK), polyaniline, polypyrrole, N,N,N',N'-tetrakis (4- Methoxyphenyl)-benzidine (N,N,N',N'-tetrakis(4-methoxyphenyl)-benzidine, TPD), 4,4'-bis[N-(1-naphthyl)-N-phenyl-amino ]biphenyl (4-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl, α-NPD), m-MTDATA (4,4',4''-Tris[phenyl(m-tolyl) amino]triphenylamine), 4,4',4''-tris(N-carbazolyl)-triphenylamine (4,4',4''-tris(N-carbazolyl)-triphenylamine, TCTA), 1,1 -bis[(di-4-toylamino)phenylcyclohexane (TAPC) and combinations thereof may include, but is not limited thereto.

The hole blocking layer is, for example, 1,4,5,8-naphthalene-tetracarboxylic dianhydride (1,4,5,8-naphthalene-tetracarboxylic dianhydride, NTCDA), vasocuproin (BCP), tris [ 3-(3-pyridyl)-mesityl] borane (3TPYMB), LiF, Alq3, Gaq3, Inq3, Znq2, Zn(BTZ)2, BeBq2, and may include at least one selected from combinations thereof, The present invention is not limited thereto.

Meanwhile, in FIG. 4 , the hole auxiliary layer 172 is illustrated as having a structure formed as a single layer, but the present invention is not limited thereto, and the hole auxiliary layer 172 may be formed as a plurality of layers in which two or more layers are stacked.

Although not intending to be bound by a particular theory, when the light emitting film according to an embodiment is employed as the light emitting layer 173, hole injection is improved to provide an improved balance between the electrons and holes to be combined, and the light emitting device 100 . It is also thought that the stability and luminescent properties of the can be increased.

Next, the emission layer 173 is positioned on the hole auxiliary layer 172 . The light emitting layer 173 includes the semiconductor nanocrystals. For example, the light emitting layer 173 may display a basic color such as blue, green, or red or a color combining them. The light emitting layer 173 may be formed by applying a dispersion solution in which the semiconductor nanocrystals are dispersed in a solvent by a method such as spin coating, inkjet or spray coating, and then drying. The emission layer 173 may have a thickness of about 5 nm or more, for example, about 10 nm to about 100 nm, for example, about 10 nm to about 50 nm, or about 15 nm to about 30 nm.

An electron auxiliary layer 174 may be positioned on the emission layer 173 . The electron auxiliary layer 174 may be positioned between the second electrode 180 and the emission layer 173 . In this case, the electron auxiliary layer 174 may be an electron injection layer that facilitates injection of electrons from the second electrode 180 into the emission layer 173 and/or an electron transport layer that facilitates the transport of electrons.

In addition, the electron auxiliary layer 174 may further include a hole blocking layer that blocks the movement of holes.

The electron transport layer and / or the electron injection layer is, for example, 1,4,5,8-naphthalene-tetracarboxylic dianhydride (1,4,5,8-naphthalene-tetracarboxylic dianhydride, NTCDA), vasocuproin ( bathocuproine, BCP), tris [3- (3-pyridyl) mesityl] borane _{(3TPYMB), LiF, Alq 3} , Gaq 3, Inq 3, Znq 2, Zn (BTZ) 2, BeBq 2 , and their It may include at least one selected from a combination, but is not limited thereto.

For example, the electron auxiliary layer 174 (eg, an electron transport layer) may include a plurality of nanoparticles. The nanoparticles may include a metal oxide including zinc.

As described above, when a metal oxide (eg, zinc magnesium oxide) is used for the electron auxiliary layer 174, the electron block has a more severe structure. By configuring , it is possible to maximize the result of improving ET while increasing PLQY and thermal stability, and improving actual device performance.

The metal oxide may be represented by Formula 2 below.

[Formula 2]

Zn _1-x M _x O

In Formula 2, M is Mg, Ca, Zr, W, Li, Ti, or a combination thereof, and may be 0 ≤ x ≤ 0.5. For example, in Formula 2, M may be magnesium (Mg). For example, in Formula 2, x may be 0 or more and 0.5 or less, such as 0.01 or more and 0.3 or less, 0.25 or less, 0.2 or less, or 0.15 or less.

The metal oxide may include zinc oxide, zinc magnesium oxide, or a combination thereof. The absolute value of the LUMO of the semiconductor nanocrystals included in the emission layer 173 may be smaller than the absolute value of the LUMO of the metal oxide. For example, the absolute LUMO value of the semiconductor nanocrystal may be greater than the absolute LUMO value of the metal oxide ETL. In the blue QD, an absolute value of LUMO may be smaller than an absolute value of LUMO of the metal oxide ETL. The electron injection in the electroluminescent device including the blue QD may be different from that of the light emitting device including red or green semiconductor nanocrystals.

The average size of the nanoparticles is 1 nm or more, for example, 1.5 nm or more, 2 nm or more, 2.5 nm or more, or 3 nm or more and 10 nm or less, 9 nm or less, 8 nm or less, 7 nm or less, 6 nm or less , or 5 nm or less. The nanoparticles may not be rod-shaped. The nanoparticles may not be in the form of nanowires.

Although the electron auxiliary layer 174 is illustrated as a single layer structure in FIG. 4 , the present invention is not limited thereto, and the electron auxiliary layer 174 may include a plurality of layers in which two or more layers are stacked.

The second electrode 180 is positioned on the electron auxiliary layer 174 . In the light emitting device 100 according to an embodiment, the first electrode 160 may be an anode and the second electrode 180 may be a cathode, but is not limited thereto. The electrode 160 may be a cathode, and the second electrode 180 may be an anode.

The second electrode 180 is also a transparent electrode, indium tin oxide (ITO), indium zinc oxide (IZO), zinc tin oxide (ZTO), copper indium oxide (CIO), copper zinc oxide (CZO), gallium zinc oxide Conductive oxides such as (GZO), aluminum zinc oxide (AZO), tin oxide (SnO ₂ ), zinc oxide (ZnO), or combinations thereof, calcium (Ca), ytterbium (Yb), aluminum (Al), silver (Ag) ), a metal such as magnesium (Mg) and a metal alloy, graphene, conductive carbon such as carbon nanotubes, or a conductive polymer such as PEDOT:PSS may be used to form a thin layer.

Hereinafter, the display device 200 including the above-described light emitting device 100 will be described with reference to FIG. 5 .

Referring to FIG. 5 , the buffer layer 126 may be positioned on the substrate 123 . The buffer layer 126 may prevent penetration of impurities and may planarize the surface of the substrate 123 .

A semiconductor layer 137 is positioned on the buffer layer 126 . The semiconductor layer 137 is formed of a polysilicon film.

The semiconductor layer 137 includes a channel region 135 not doped with impurities, a source region 134 and a drain region 136 positioned on both sides of the channel region 135 , and the source region 134 . ) and the drain region 136 may each be doped. Here, the doped ionic impurities may vary depending on the type of the thin film transistor.

A gate insulating layer 127 is positioned on the semiconductor layer 137 , and a gate wiring including a gate electrode 133 is positioned on the gate insulating layer 127 . In this case, the gate electrode 133 is positioned to overlap a portion of the semiconductor layer 137 , in particular, the channel region 135 .

An interlayer insulating layer 128 is positioned on the gate insulating layer 127 and the gate electrode 133 . The gate insulating layer 127 and the interlayer insulating layer 128 have a first contact hole 122a and a second contact hole 122b overlapping the source region 134 and the drain region 136 of the semiconductor layer 137 . have

A data line including a source electrode 131 and a drain electrode 132 is positioned on the interlayer insulating layer 128 .

The source electrode 131 and the drain electrode 132 are respectively connected to the semiconductor through the first contact hole 122a and the second contact hole 122b formed in the interlayer insulating layer 128 and the gate insulating layer 127 , respectively. It is electrically connected to the source region 134 and the drain region 136 of the layer 137 .

The above-described semiconductor layer 137 , gate electrode 133 , source electrode 131 , and drain electrode 132 form the thin film transistor 130 , and the configuration of the thin film transistor 130 is not limited to the above-described example. , it can be variously changed to a known configuration that can be easily implemented by an expert in the art.

Next, a planarization layer 124 is positioned on the interlayer insulating layer 128 and the data line. The planarization layer 124 serves to eliminate a step difference in order to increase the luminous efficiency of the light emitting device 100 positioned thereon.

The planarization layer 124 may have a third contact hole 122c overlapping the drain electrode 132 .

Here, the exemplary embodiment is not limited to the above-described structure, and in some cases, one of the planarization layer 124 and the interlayer insulating layer 128 may be omitted.

Next, the first electrode 160 included in the light emitting device 100 is positioned on the planarization layer 124 . The first electrode 160 may be a pixel electrode. The first electrode 160 is connected to the drain electrode 132 through the third contact hole 122c of the planarization layer 124 .

A pixel defining layer 125 having an opening overlapping with the first electrode 160 is positioned on the planarization layer 124 . A light emitting device layer 170 may be positioned in each opening of the pixel defining layer 125 . That is, a pixel region in which each light emitting device layer 170 is located may be defined by the pixel defining layer 125 .

A light emitting device layer 170 is positioned on the first electrode 160 . The light emitting device layer 170 may include a hole auxiliary layer 172 , a light emitting layer 173 and an electron auxiliary layer 174 as described with reference to FIG. 4 , and is the same as the above-described components. A description is omitted.

In addition, the second electrode 180 is positioned on the light emitting device layer 170 . The second electrode 180 may be a common electrode. The first electrode 160 , the light emitting device layer 170 , and the second electrode 180 form the light emitting device 100 .

Each of the first electrode 160 and the second electrode 180 may be formed of a transparent conductive material or may be formed of a transflective or reflective conductive material. According to the type of material forming the first electrode 160 and the second electrode 180 , the display device 200 may be a top emission type, a bottom emission type, or a double side emission type.

An overcoat 190 protecting the second electrode 180 is positioned on the second electrode 180 .

In addition, a thin film encapsulation layer 121 is positioned on the overcoat 190 . The thin film encapsulation layer 121 seals and protects the light emitting device 100 and the circuit part (not shown) positioned on the substrate 123 from the outside.

The thin film encapsulation layer 121 includes organic encapsulation films 121a and 121c and inorganic encapsulation films 121b and 121d that are alternately stacked one by one. In FIG. 5 , as an example, two organic encapsulation films 121a and 121c and two inorganic encapsulation films 121b and 121d are alternately stacked one by one to form the thin film encapsulation layer 121 , but the present invention is not limited thereto. , the structure of the thin film encapsulation layer 121 can be variously modified as needed.

Hereinafter, specific embodiments of the invention are presented. However, the examples described below are only for specifically illustrating or explaining the invention, and the scope of the invention is not limited thereto.

[Analysis method]

(1) ET (electron transport) analysis

Evaluate ET (electron transport) characteristics with CS-2000 (manufactured by MacScience) that can measure voltage-current-luminance characteristics of QD-LED and OLED devices.

(2) Photoluminescence analysis

Hitachi F-7000 A photoluminescence (PL) spectrum of the nanocrystals prepared at an irradiation wavelength of 372 nm is obtained using a spectrometer.

(3) hole and electron transport capacity analysis

While applying a voltage, the current according to the voltage is measured with a Keithley 2635B source meter attached to the CS-2000 equipment to evaluate the hole and electron transport ability.

[Preparation Example 1: Preparation of semiconductor nanocrystals]

(Preparation Example 1-1: Preparation of semiconductor nanocrystals containing an oleate ligand (hereinafter also referred to as 'OA-QD'))

(1) Preparation of ZnTeSe core

Selenium and tellurium are dispersed in trioctylphosphine (TOP), respectively, to obtain 2M Se/TOP stock solution and 2M Te/TOP stock solution. Prepare a trioctylamine solution containing 0.125 mmol of zinc acetate and 0.25 mmol of palmitic acid in a 400 mL reaction flask. The solution is heated to 120° C. under vacuum. After 1 hour, the atmosphere in the reactor is switched to nitrogen.

After heating the reactor to 300 °C, the Se/TOP stock solution and the Te/TOP stock solution prepared above are quickly injected, and the reaction is carried out for 1 hour. After completion of the reaction, the reaction solution is cooled to room temperature, acetone is added, and the precipitate obtained by centrifugation is dispersed in toluene to obtain a dispersion of ZnTeSe semiconductor nanocrystal core.

(2) Preparation of ZnTeSe/ZnSeS core/shell semiconductor nanocrystals with blue light emission

0.9 mmol of zinc acetate, 1.8 mmol of oleic acid, and 10 mL of trioctylamine are placed in a reactor and vacuum-treated at 120° C. for 10 minutes. After replacing the inside of the reaction flask with nitrogen, the temperature was raised to 280 °C. Put the toluene dispersion (OD=optical density of 1 ^st excitonic absorption, OD=0.45) of the ZnTeSe core prepared above within 10 seconds, add 0.6 mmol of Se/TOP and 2.0 mmol of S/TOP, and react for 120 minutes to obtain the reaction solution (Crude ) to get After completion of the reaction, ethanol is added to the reaction solution rapidly cooled to room temperature (24 ° C.) to form a precipitate, which is separated by centrifugation and redispersed in cyclohexane to prepare ZnSe/ZnSeS semiconductor nanocrystals. It is confirmed that the PL emission center peak of the crystal is approximately 450 nm and the PLQY is 60%.

(Preparation Example 1-2: Preparation of semiconductor nanocrystals containing chloride (hereinafter also referred to as 'Cl-QD'))

The semiconductor nanocrystals obtained in Preparation Example 1-1 are dispersed in cyclohexane to obtain an organic semiconductor nanocrystal dispersion. Zinc chloride is dissolved in ethanol to obtain a solution of zinc chloride with a concentration of 10% by weight. Add 0.01 mL of zinc chloride solution to the organic dispersion of semiconductor nanocrystals prepared above, and stir at 60° C. for 30 minutes for surface exchange reaction. After the reaction, ethanol is added to induce precipitation, and the semiconductor nanocrystals are recovered by centrifugation. The same surface exchange reaction is repeated with respect to the recovered semiconductor nanocrystals to obtain semiconductor nanocrystals containing chloride on the surface.

(Preparation Example 1-3: Preparation of semiconductor nanocrystals containing benzoate (hereinafter also referred to as 'BzA-QD'))

The semiconductor nanocrystals obtained in Preparation Example 1-1 are dispersed in cyclohexane to obtain a semiconductor nanocrystal organic dispersion. Put 0.01 mL of a solution containing benzoic acid (concentration of 10% by weight) into the organic dispersion of semiconductor nanocrystals prepared above, and stir at 60° C. for 30 minutes for a surface exchange reaction. After the reaction, ethanol is added to induce precipitation, and the semiconductor nanocrystals are recovered by centrifugation. The same surface exchange reaction is repeated with respect to the recovered semiconductor nanocrystals to obtain treated semiconductor nanocrystals containing benzoate on the surface.

(Preparation Example 1-4: Preparation of semiconductor nanocrystals containing chloride and benzoate (hereinafter also referred to as 'BzA/Cl-QD'))

A semiconductor nanocrystal containing chloride on the surface obtained in Preparation Example 1-2 is dispersed in toluene to obtain an organic semiconductor nanocrystal dispersion. Put 0.01 mL of a solution containing benzoic acid (concentration of 10% by weight) into the organic dispersion of semiconductor nanocrystals prepared above, and stir at 60° C. for 30 minutes for a surface exchange reaction. After the reaction, ethanol is added to induce precipitation, and the semiconductor nanocrystals are recovered by centrifugation. The same surface exchange reaction is repeated with respect to the recovered semiconductor nanocrystals to obtain semiconductor nanocrystals containing chloride and benzoate on the surface.

[Preparation Example 2: Method for manufacturing a light emitting film]

(Preparation Example 2-1: Preparation of light emitting film)

0.2 mL of each semiconductor nanocrystal dispersion prepared in Preparation Example 1 was spin-coated on a glass substrate to form a film. The formed film is heat-treated at 80° C. for 30 minutes to obtain a light-emitting film.

(Preparation Example 2-2: Spin-dry treatment light emitting film (SPD) preparation)

0.2 mL of each semiconductor nanocrystal dispersion prepared in Preparation Example 1 was spin-coated on a glass substrate to form a film. The formed film is heat-treated at 80° C. for 30 minutes to obtain a light-emitting film.

An ethanol solution of zinc chloride (concentration: 10 mg/mL) was added dropwise onto the light emitting film _{, and reacted for 1 minute to obtain a ZnCl 2 treated light emitting film.} The treated light emitting film is washed 5 times with ethanol, and the washed film is heat treated at 80° C. for 30 minutes to obtain a spin-dry-treated light emitting film (SPD light emitting film).

[Preparation Example 3: Preparation of light emitting device]

A device having a stacked structure of ITO / PEDOT:PSS (30 nm) / TFB (25 nm) / QD light emitting layer (20 nm) / ZnMgO (20 nm) / Al (1000 nm) is manufactured as follows.

(1) After surface treatment with UV-ozone for 15 minutes on a glass substrate on which ITO was deposited, spin-coated with a PEDOT:PSS solution (HC Starks), heat-treated at 150 ° C. for 10 minutes in an air atmosphere, and again N ₂ atmosphere Heat treatment at 150 °C for 10 minutes to form a 30nm-thick hole injection layer. Then, on the hole injection layer, poly[(9,9-dioctylfluorenyl-2,7-diyl-co(4,4'-(N-4-butylphenyl)diphenylamine] solution (TFB)(Sumitomo)) was spin-coated and heat-treated at 150° C. for 30 minutes to form a hole transport layer.

(2) On the obtained hole transport layer, as in the method of Preparation Example 2-1, spin-coated each of the core-shell semiconductor nanocrystals obtained in Preparation Example 1, and heat-treated at 80° C. for 30 minutes to form a light emitting layer on the hole transport layer do.

Alternatively, as in the method of Preparation Example 2-2, each core-shell semiconductor nanocrystal obtained in Preparation Example 1 is spin-coated on the hole transport layer, heat-treated at 80° C. for 30 minutes to form a film, and then zinc on the film A solution in which chloride was dissolved in ethanol (concentration: 0.1 g/mL) was added dropwise and left to stand, then the remaining solution was removed and washed several times with ethanol, and the washed film was dried on a hot plate at 80° C. to form an SPD-treated light emitting layer do.

(3) A solution of ZnMgO nanoparticles (solvent: ethanol, optical density: 0.5 a.u) is spin-coated on the prepared light emitting layer, and heat-treated at 80° C. for 30 minutes to form an electron auxiliary layer. A light emitting device as shown in FIG. 4 is manufactured by vacuum-depositing aluminum (Al) on a part of the surface of the obtained electron auxiliary layer to form a second electrode.

[Experimental example]

(Experimental Example 1: ET (electron transport) characteristic evaluation)

Substituted on the surface of the semiconductor nanocrystals prepared in Preparation Example 1-1 After replacing oleate with dodecanethiol (DDT) or zinc-dodecanethiol (ZnDDT), which are shorter organic ligands, ET (electron transport) characteristics of semiconductor nanocrystals before and after the substitution were measured and the Table 1 summarizes the results.

ZnMgO
(resin aging, D+7) ZnMgO
(no resin) OETL ET@8V ET@8V ET@8V OA 15.6086 1.349 4.30748 DDT 15.3538 3.374 2.62573 ZnDDT 3.47038 1.218 2.44568

Referring to Table 1, it can be seen that ET (electron transport) properties are not improved even when the second organic ligand, oleate (C18), is substituted (OA is replaced with DDT or ZnDDT, which is a short organic ligand). can

In addition, the light emitting film prepared by the method of Preparation Example 2-1 (hereinafter referred to as 'Cl-QD') using the semiconductor nanocrystals containing chloride on the surface of Preparation Example 1-2 and Preparation Example 1 Using the semiconductor nanocrystals prepared in -1 to evaluate the hole and electron transport ability of the spin-dry-treated light emitting film (hereinafter referred to as 'SPD-QD') prepared by the method of Preparation Example 2-2, and , the results are summarized in Table 2, Table 3, FIG. 6, and FIG. 7 .

HOD HT
(3rd sweep J, mA/cm ² ) 20nm single light emitting film Cl-QD SPD-QD 5 V 0.036 0.242 8 V 0.395 2.118 12 V 24.14 101.50

EOD HT
(3rd sweep J, mA/cm ² ) 20nm single light emitting film Cl-QD SPD-QD 5 V 220.2 283.8 8 V 411.6 520.0 12 V 874.4 1221.3

Referring to Tables 2, 3, 6, and 7, it can be seen that the organic material of OA-QD is removed by the spin-dry treatment of the _{inorganic metal salt (ZnCl 2 ), so that the hole conduction properties are improved, but the electon conduction} It can be seen that the properties are not improved. OA-QD and Cl-QD have almost similar ET (electron transport) characteristics.

(Experimental Example 2: Evaluation of photoluminescence of the light emitting film)

After preparing a light emitting film by the method of Preparation Example 2-1 using the semiconductor nanocrystals prepared in Preparation Examples 1-2, Preparation Examples 1-3, and Preparation Examples 1-4, and evaluating the PL characteristics, Table 4, FIG. It is summarized in 8 and FIG.

In Table 4, FIGS. 8 and 9, BzA-QD (x2) is a double increase in the content of BzA compared to BzA-QD (x1), and BzA/Cl-QD (BzA: ZnCl ₂ =1:1) is a case in which _{the weight ratio of BzA to ZnCl 2} is 1:1, and BzA/Cl-QD (BzA:ZnCl ₂ =2:1) is a case in which the weight ratio _{of BzA to ZnCl 2 is 2:1.}

QD type fair Abs. (%) A-QY (%) %QY Preparation 1-2 Cl-QD before heat treatment 9.0% 85.9% 100% 80℃ 30 minutes 9.7% 71.4% 83% Preparation 1-3 BzA-QD (x1) before heat treatment 7.2% 67.6% 100% 80℃ 30 minutes 7.7% 51.1% 76% BzA-QD (x2) before heat treatment 7.4% 75.2% 100% 80℃ 30 minutes 8.1% 50.8% 68% Preparation Example 1-4 BzA/Cl-QD
(BzA:ZnCl ₂ =1:1) before heat treatment 13.3% 91.0% 100% 80℃ 30 minutes 13.8% 84.7% 93% BzA/Cl-QD
(BzA:ZnCl ₂ =2:1) before heat treatment 10.3% 91.3% 100% 80℃ 30 minutes 11.5% 78.4% 86%

Referring to Table 4, 8 and 9, it can be seen that BzA-QD (Preparation Example 1-3) has poor PLQY compared to Cl-QD (Preparation Example 1-2). On the other hand, in the case of BzA/Cl-QD (Preparation Example 1-4), it can be seen that the PLQY is high and the thermal stability is the best in the PL evaluation before and after the thin film heat treatment.

(Experimental Example 3: Evaluation of hole and electron transport ability of light emitting device)

Semiconductor nanoparticles prepared in Preparation Example 1-1 (OA-QD), Preparation 1-2 (Cl-QD), Preparation Example 1-3 (BzA-QD), and Preparation Example 1-4 (BzA/Cl-QD) Using the crystal, a light emitting device was manufactured as in Preparation Example 3, and hole and electron transport ability was evaluated, and then summarized in Tables 5, 6, 10, and 11 .

HOD, 3rd sweep
(mA/cm ² ) Cl-QD BzA-QD BzA/Cl-QD
(BzA:ZnCl ₂ =1:1) @5V 0.01 0.01 0.03 @8V 0.04 0.13 0.13 @12V 1.66 1.76 2.32

EOD, 3rd sweep (mA/cm ² ) OA-QD Cl-QD BzA/Cl-QD
(BzA:ZnCl ₂ =1:1) @5V 0.26 0.18 5.11 @8V 1.88 0.79 31.22 @12V 12.58 4.99 183.2

Referring to Tables 5, 6, 10, and 11, it can be seen that BzA/Cl-QD increases the amount of ET current compared to OA-QD or Cl-QD, and the HT characteristic is also at the same level as that of Cl-QD. can

(Experimental Example 4: Device Performance Evaluation 1 of Light-Emitting Device)

A light emitting device manufactured using the semiconductor nanocrystals prepared in Preparation Example 1-1 (hereinafter referred to as 'OA-QD'), and a light emitting device treated with the same (hereinafter referred to as 'SPD-QD') , and a light emitting device manufactured using the semiconductor nanocrystals prepared in Preparation Example 1-3 (hereinafter referred to as 'BzA-QD', treated with 10 mM BzA), and a light emitting device treated with SPD (hereinafter referred to as 'BzA-QD') , expressed as 'BzA/SPD-QD'), and the results are summarized in Table 7.

In addition, the same experiment was conducted for the case where benzoic acid (BzA) was replaced with oxalic acid (OxA) and citric acid (CtA) (treated with 10 mM), and the results are also summarized in Table 7.

Passive EA (4.4V) OA-QD SPD-QD BzA (10 mM)-QD OxA (10 mM)-QD CtA (10 mM)-QD BzA/SPD-QD OxA/SPD-QD CtA/SPD-QD EQE Max 12.5 12.4 10.5 10.1 12 14.2 11.8 11.7 Lum Max
(Cd/m ² ) 58360 61810 55210 33580 49270 69950 63720 54120 EQE@ 1000nt 12.3 11.7 9.9 9.8 11.9 14.1 11.7 11.6 EQE@ 10000nt 11.7 12.1 10.5 9 11.4 13 11.3 11.1 EQE@ 20000nt 10.1 10.7 9.5 7.5 9.6 11.5 10.6 9.7 Cd/A Max 11.5 11.3 9.3 8.9 11.1 13.9 11.1 11.2 V@5mA 3.6 3.6 3.6 3.2 3.6 2.9 3.2 3.4 Cd/m ² @5mA 543 444 345 429 523 658 511 540 V@1nt 2.6 2.7 2.7 2.6 2.6 2.4 2.5 2.5 Lamda Max 462 462 461 461 461 463 463 463 FWHM 38 38 37 36 38 38 39 39 T90(h) 3.78 4.75 2.9 0.05 0.99 4.59 2.22 1.56 T50(h) 18.5 24.4 17.6 0.5 9.3 33.7 17.4 15.2

Referring to Table 7, it can be seen that when treated alone with benzoic acid (BzA), oxalic acid (OxA) or citric acid (CtA), the performance is worse than when oleic acid (OA) is included, and BzA / SPD treated In this case, it can be seen that the device performance is maximized.

(Experimental Example 5: Device Performance Evaluation 2 of Light-Emitting Device)

Using the semiconductor nanocrystals prepared in Preparation Example 1-2, a light emitting film stacked in two layers was prepared, one layer of which was subjected to SPD treatment by the method of Preparation Example 2-2 (hereinafter, 'Cl/SPD-QD /Cl'), using the semiconductor nanocrystals prepared in Preparation Example 1-3, to prepare a light emitting film stacked in two layers, one layer of which is SPD-treated by the method of Preparation Example 2-2 ( Hereinafter, denoted as 'BzA/SPD-QD/Cl'), using the semiconductor nanocrystals prepared in Preparation Example 1-4, a light emitting film stacked in two layers is prepared, one layer of which is Preparation Example 2- The light emitting device is manufactured by performing SPD treatment in the method of 2 (hereinafter referred to as 'BzA/Cl/SPD-QD/Cl').

The device performance of the manufactured light emitting device was measured, and the results are summarized in Table 8. In Table 8 below, BzA (x1) is a 10-fold increase in the content of BzA compared to BzA-QD (x0.1).

Top/bottom layer (20nm/20nm) Cl/SPD-QD/Cl BzA (x0.1)/SPD-QD/Cl BzA(x1)/SPD-QD/Cl BzA(x0.1)/Cl/SPD-QD/Cl BzA(x1)/Cl/SPD-QD/Cl EQE Max 12.2 14.4 14.5 13.1 14.1 Lum(Max)(Cd/m ² ) 56760 68120 72920 69370 73220 EQE@1000nt 12.1 12.9 12.5 12.1 11.9 EQE@10000nt 9.5 11.4 11.9 10.3 11.2 EQE@20000nt 8 9.6 10.4 8.9 9.6 Cd/A Max 13.4 15.2 14.8 14.6 14.6 V@5mA 3.5 3.4 3.4 3.4 3.4 Cd/m ² @5mA 660 693 649 678 635 V@1nt 2.6 2.5 2.5 2.6 2.5 Lamda Max 465 464 464 465 464 FWHM 41 42 41 41 41 CIE x 0.131 0.132 0.132 0.131 0.132 CIE y 0.146 0.142 0.138 0.153 0.143 T95(h) 9.79 16.94 14.6 17.67 16.04 T50(h) 75.6h@63% 75.6h@70% 75.6h@66% 75.5h@74% 62h@74% OVS (%) 101 102 102 102 102

Referring to Table 8, it can be seen that the device performance is increased when the BzA content is increased 10 times from x0.1 to x1 at 150 ° C. Luminance 70500nit -> 77400nit).

(Experimental Example 6: FT-IR measurement of the light emitting film)

FT-IR measurement of the light emitting film (hereinafter referred to as 'BzA/Cl/SPD-QD') treated with SPD in the method of Preparation Example 2-2 using the semiconductor nanocrystals prepared in Preparation Example 1-4 .

As a result, it can be confirmed that benzoate remains in the thin film during the BzA/Cl/SPD mixed treatment. That is, according to the BzA/Cl/SPD mixing treatment, BzA is adsorbed to benzoate (carboxylate (COO-) terminus), which results in 1413 cm ^-1 and 1596 cm ^-1 peaks compared to the SPD membrane.

Although preferred embodiments of the invention have been described in detail above, the scope of the invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the invention as defined in the following claims are also provided. will belong to

100: light emitting element 123: substrate
200: display device 130: thin film transistor
160: first electrode 172: hole auxiliary layer
173: light emitting layer 174: electron auxiliary layer
180: second electrode

Claims (20)

An anion of an inorganic metal salt and a first organic ligand are included on the surface,
The first organic ligand comprises a substituted or unsubstituted C6 to C30 aromatic ring group, a substituted or unsubstituted C3 to C30 aromatic heterocyclic group, or a combination thereof and a carboxylate group,
semiconductor nanocrystals. In claim 1,
The semiconductor nanocrystal includes a core including a first semiconductor nanocrystal and a shell including a second semiconductor nanocrystal disposed on the core and having a composition different from that of the first semiconductor nanocrystal. In claim 1,
The semiconductor nanocrystal is a semiconductor nanocrystal comprising InP, InZnP, ZnSe, ZnSeTe, or a combination thereof. In claim 1,
The semiconductor nanocrystal is a semiconductor nanocrystal comprising zinc and sulfur in an outermost layer. In claim 1,
The inorganic metal salt is a semiconductor nanocrystal comprising an inorganic metal halide, an inorganic metal sulfate, an inorganic metal nitrate, an inorganic metal thiocyanate, or a combination thereof. In claim 1,
The metal of the inorganic metal salt is zinc (Zn), indium (In), gallium (Ga), magnesium (Mg), lithium (Li), nickel (Ni), tin (Sn), copper (Cu), silver (Ag) , cobalt (Co), or a semiconductor nanocrystal comprising a combination thereof. In claim 1,
The inorganic metal salt is zinc chloride, zinc bromide, zinc iodide, zinc nitrate, zinc sulfate, zinc thiocyanate, indium chloride, indium bromide, indium iodide, indium nitrate, indium sulfate, indium thiocyanate, gallium chloride. Gallium Bromide, Gallium Iodide, Gallium Nitrate, Gallium Sulphate, Gallium Thiocyanate, Magnesium Chloride, Magnesium Bromide, Magnesium Iodide, Magnesium Nitrate, Magnesium Sulphate, Magnesium Thiocyanate, Lithium Chloride, Lithium Bromide, Lithium Iodide, lithium nitrate, lithium sulfate, lithium thiocyanate, nickel chloride, nickel bromide, nickel iodide, nickel nitrate, nickel sulfate, nickel thiocyanate, tin chloride, tin bromide, tin iodide, tin nitrate, Tin sulfate, tin thiocyanate, copper chloride, copper bromide, copper iodide, copper nitrate, copper sulfate, copper thiocyanate, silver chloride, silver bromide, silver iodide, silver nitrate, silver sulfate, silver thiocyanate A semiconductor nanocrystal comprising an acid salt, cobalt chloride, cobalt bromide, cobalt iodide, cobalt nitrate, cobalt sulfate, cobalt thiocyanate, or a combination thereof. In claim 1,
The first organic ligand is a compound represented by the following formula (1),
Semiconductor nanocrystals:
[Formula 1]

In Formula 1,
Wherein Ar ₁ is a substituted or unsubstituted monocyclic aromatic ring group, a substituted or unsubstituted condensed polycyclic aromatic ring group, or two or more monocyclic aromatic rings a group or an aromatic ring group in which two or more condensed polycyclic aromatic ring groups are linked by a linker,
L is a single bond, a substituted or unsubstituted C1 to C30 alkylene group, or -CR ^a =CR ^b - or -C≡C- (wherein R ^a and R ^b are each independently hydrogen, or C1 to C10 is an alkyl group of) an unsaturated linker,
wherein X is a carboxylate group,
Y is a hydroxyl group, a halogen group, an amine group, or a nitro group, and n is an integer of 0 to 6. In claim 8,
The aromatic ring group is benzene, biphenyl, naphthalene, anthracene, phenanthrene, pyrene, perylene, fluorene, pentalene, pyrazole, imidazole, thiazole, triazole, carbazole, pyridine, pyridazine , pyrimidine, pyrazine, triazine, indazole, indolizine, benzimidazole, benzthiazole, benzothiophene, benzopurine, isoquinoline, or purine. In claim 1,
The first organic ligand is benzoate, hydroxy benzoate, halo-benzoate, amino-benzoate, nitro-benzoate, 4- A semiconductor nanocrystal comprising 4-biphenyl carboxylate, cinnamate, or a combination thereof. In claim 1,
The semiconductor nanocrystals are on the surface of the semiconductor nanocrystals, RCOOH, RNH ₂ , R ₂ NH, R ₃ N, RSH, RH ₂ PO, R ₂ HPO, R ₃ PO, RH ₂ P, R ₂ HP, R ₃ P, ROH, RCOOR', RPO(OH) ₂ , RHPOOH, or R ₂ POOH, wherein R and R' are each independently hydrogen, a C1-C40 substituted or unsubstituted aliphatic hydrocarbon, or a C6-C40 substituted or a second organic ligand comprising an anion of an unsubstituted aromatic hydrocarbon, or a combination thereof, wherein at least one R in each ligand is not hydrogen. In claim 1,
The weight ratio of the anion of the inorganic metal salt and the first organic ligand is 30 to 60: 10 to 30 of the semiconductor nanocrystal. In claim 11,
The weight ratio of the second organic ligand, the anion of the inorganic metal salt, and the first organic ligand is 30 to 60: 30 to 60: 10 to 30 of a semiconductor nanocrystal. A light-emitting film comprising a plurality of semiconductor nanocrystals according to claim 1 . disposing a film comprising a plurality of semiconductor nanocrystals on a substrate; and
Treating the plurality of semiconductor nanocrystals with a solution containing an inorganic metal salt in a polar solvent to bind the anions of the inorganic metal salt to the plurality of semiconductor nanocrystals; processing the semiconductor nanocrystals to bind the first organic ligand to the plurality of semiconductor nanocrystals;
The first organic ligand includes a substituted or unsubstituted C6 to C30 aromatic ring group, a substituted or unsubstituted C3 to C30 aromatic heterocyclic group, or a combination thereof and a carboxylate group, a method of manufacturing a light emitting film . a first electrode and a second electrode facing each other, and
A light emitting device comprising the light emitting film according to claim 14 disposed between the first electrode and the second electrode. 17. In claim 16,
The light emitting device includes an electron injecting layer (EIL), an electron transporting layer (ETL), a hole blocking layer (HBL), or a combination thereof between the second electrode and the light emitting layer. A light emitting device further comprising an electron auxiliary layer selected from. 17. In claim 16,
The electron auxiliary layer is a light emitting device including nanoparticles including zinc metal oxide. In claim 18,
The zinc metal oxide is a light emitting device represented by the following Chemical Formula 2:
[Formula 2]
Zn _1-x M _x O
In Formula 2,
M is Mg, Ca, Zr, W, Li, Ti, Y, Al, or a combination thereof,
0 ≤ x ≤ 0.5. A display device comprising the light emitting element according to claim 16 .

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