KR102145056B1 - Light conversion film comprising a quantum dot layer, backlight units for display devices including the light conversion film, and method of manufacturing a quantum dot dispersion - Google Patents

Abstract

The present invention provides a light conversion film that comprises a first transparent support layer formed on an upper surface of a quantum dot layer and a second transparent support layer formed on a lower surface of the quantum dot layer and has a thickness of 120 to 400 μm, wherein the quantum dot layer includes, based on the total weight of the quantum dot layer: 0.4 to 2.0 wt% of quantum dot particles containing not less than 5 and less than 35 wt% of cadmium; 0.05 to 0.75 wt% of quantum dot particles not containing cadmium; 0.1 to 10 wt% of a scattering agent; and 75 to 98 wt% of a matrix material. The light conversion film has a cadmium content of 10 to 100 ppm. The present invention also provides a backlight unit for a display device including the light conversion film, the display device, a composition for forming the quantum dot layer, and a method for producing a particle dispersion.

Description

Light conversion film comprising a quantum dot layer, backlight units for display devices including the light conversion film, and a method of manufacturing a light conversion film including a quantum dot layer, a backlight unit for a display device including the light conversion film, and method of manufacturing a quantum dot dispersion}

The present invention relates to a light conversion film including a quantum dot layer, a backlight unit for a display device including the light conversion film, and a method of manufacturing a quantum dot dispersion.

Cadmium is a heavy metal substance and is also the main cause of soil, water and air pollution.It penetrates the human body through various foods that lead to the food chain such as grains, vegetables, meat, fish and shellfish, as well as contaminated drinking water, and mixes with dust in the atmosphere by respiration. It is inhaled and remains in the human body as it is. As such, heavy metals that have penetrated the human body through various pathways cause respiratory disease, vomiting, fatigue, and weakness, and in severe cases it destroys bone tissue and paralyzes muscles, causing itai-itai disease, which is a terrible pollution disease, and even kills life. Moreover, heavy metals have a strong persistence and are afraid that when they accumulate in the tissues inside the body, they cause various harm without being discharged from the body. For this reason, in the European Union's Restriction of Hazardous Substances Directive (RoHS), six items of lead, cadmium, mercury, hexavalent chromium, phthalates and bromine-based flame retardants are used in electronic products and electrical devices. Is limited to being. These materials are suggested as 0.1% (1000 ppm) based on the weight of each material, and in particular, cadmium is more strictly limited to 0.01% (100 ppm).

Quantun Dot (QD) is a semi-conducting nano-sized particle of several nano-sized size with quantum confinement effect, and exhibits excellent optical and electrical properties that general semiconducting materials do not have in a bulk state. . Quantum dots can emit light when stimulated with energy such as light, and the color of the emitted light varies depending on the size of the particles. In the case of using such quantum dots, since it is possible to implement a large-area high-resolution display with good color purity, excellent color reproducibility, and good video characteristics, many studies on quantum dots are being conducted.

For example, cadmium-based quantum dot particles are actually commercialized and applied as a light conversion film to a backlight unit (hereinafter referred to as BLU) of a liquid crystal display. However, among the quantum dot particles containing cadmium, the green emitting quantum dot particles having a core in the form of CdSe or CdS and generally having a maximum absorption wavelength of 515 nm to 535 nm contain cadmium in 35 to 55%, and the particle size is relatively large and the maximum Red emission quantum dot particles having an absorption wavelength of 620nm to 640nm contain 55 to 80% of cadmium. When the cadmium content contained in the quantum dot is high as described above, it is impossible to secure color purity and color reproducibility in the photoconversion film for display by adjusting the content of cadmium to an acceptable range.

In order to solve the above problems, US20170250322A1 describes a method of securing a relatively small amount of cadmium-content quantum dot particles by coating a thick shell on a nanostructure having a CdSe core. However, when a thick shell is formed, the optical density is lowered, resulting in a decrease in quantum efficiency, and the particle size distribution of the quantum dots is widened, resulting in a relatively large full width at half-maxium (FWHM), resulting in low color purity and color reproducibility. Losing has a problem.

Indium phosphite (hereinafter referred to as InP)-based quantum dot particles, which have been studied recently, are in the spotlight due to their eco-friendly properties. However, the InP-based quantum dot particles have a full half width of 35 to 45 nm and a quantum efficiency of 70 to 85%, which is significantly lowered compared to the full half width of CdSe or CdS-based quantum dot particles of 20 to 30 nm and 85 to 95% quantum efficiency, Moisture and oxygen are also vulnerable, so there is a limitation that it cannot be applied alone to a display, especially a light conversion film for a backlight unit of a liquid crystal display.

US Patent Publication No. US20170250322A1

The present invention was devised to solve the above problems of the prior art,

An object of the present invention is to provide a photoconversion film having a cadmium content of 100 ppm or less while securing the maximum advantage of quantum dot particles containing cadmium, exhibiting excellent luminance and color reproduction characteristics.

In addition, by including the light conversion film, it is an object to provide a display device and a backlight unit for a display device that is safe and has excellent luminance and color reproduction characteristics.

In addition, it is an object of the present invention to provide an efficient method for producing a dispersion of quantum dot particles and quantum dot particles containing cadmium used in the light conversion film.

The present invention

A photoconversion film comprising a first transparent support layer formed on the upper surface of the quantum dot layer and a second transparent support layer formed on the lower surface of the quantum dot layer and has a thickness of 120 to 400 μm,

The quantum dot layer is based on the total weight of the quantum dot layer, 0.4 to 2.0% by weight of quantum dot particles containing cadmium in an amount of 5 to less than 35% by weight; 0.05 to 0.75% by weight of quantum dot particles not containing cadmium; 0.1 to 10% by weight of a scattering agent; And 75 to 98% by weight of the matrix material; and

It provides a light conversion film in which the cadmium content of the film is 10 to 100 ppm.

In addition, the present invention,

It provides a backlight unit for a display device including the light conversion film.

In addition, the present invention,

It provides a display device including the backlight unit.

In addition, the present invention

(a) 0.4 to 2% by weight of cadmium-containing quantum dot particles having a cadmium (Cd) content of 5 to less than 35% by weight;

(b) 0.05 to 0.75% by weight of quantum dot particles not containing cadmium;

(c) 75 to 98% by weight of the matrix material; And

(d) 0.1 to 10% by weight of a scattering agent; containing

It provides a composition for forming a quantum dot layer.

In addition, the present invention

(a) 0.1 to 4.5 moles of a cation precursor containing at least one selected from a group II element and a group III element not containing cadmium (Cd) per 1 mole of the cation precursor containing cadmium (Cd), and V Reacting 0.5 to 6.0 moles of an anion precursor containing at least one selected from a group element and a group VI element;

(b) separating and drying the particles generated in step (a) to prepare quantum dot particles having a cadmium content of 5 to 35% by weight; And

(c) dispersing the quantum dot particles having a cadmium content of 5 to 35% by weight in a solvent or a compound containing a double bond at a concentration of 1 to 20% by weight;

It provides a method for preparing a dispersion of quantum dot particles comprising a.

The photo-conversion film of the present invention provides the effect of substantially controlling the cadmium content to 100 ppm or less while securing the maximum advantage of quantum dot particles including cadmium, exhibiting excellent luminance and color reproduction characteristics.

In addition, the present invention provides a backlight unit and a display device for a display device that is safe and has excellent luminance and color reproduction characteristics by including the light conversion film.

In addition, the present invention provides an efficient method for producing quantum dot particles and a dispersion of quantum dot particles containing cadmium used in the light conversion film.

1 is a diagram schematically showing the structure of a liquid crystal display device,
2 is a diagram schematically showing an embodiment of the light conversion film of the present invention.

The present invention

A photoconversion film comprising a first transparent support layer formed on the upper surface of the quantum dot layer and a second transparent support layer formed on the lower surface of the quantum dot layer and has a thickness of 120 to 400 μm,

The quantum dot layer is based on the total weight of the quantum dot layer, 0.4 to 2.0% by weight of the quantum dot particles containing cadmium in an amount of 5 to less than 35% by weight; 0.05 to 0.75% by weight of quantum dot particles not containing cadmium; 0.1 to 10% by weight of a scattering agent; And 75 to 98% by weight of the matrix material; and

The film has a cadmium content of 10 to 100 ppm, more preferably 10 to 80 ppm, and even more preferably 10 to 60 ppm.

In the quantum dot particles containing 5 or more to less than 35% by weight of cadmium, when the cadmium content is less than 5% by weight, it is difficult to produce quantum dot particles exhibiting sufficient color reproducibility and color purity, and when it is more than 35% by weight, cadmium content This is not preferable because it increases and causes environmental problems. The cadmium content is more preferably 10 to 30% by weight.

Quantum dot particles containing 5 or more to less than 35% by weight of cadmium have a maximum absorption wavelength of 525 to 540 nm, and quantum dot particles not containing cadmium have a maximum absorption wavelength of 625 to 640 nm. When the quantum dot particles having the same wavelength as described above are included in the quantum dot layer, a green photoconversion film having high color reproducibility and color purity can be obtained while minimizing cadmium content.

Quantum dot particles containing 5 or more to less than 35% by weight of cadmium preferably have a half width of 20 to 30 nm. If the half width of the quantum dot particle is less than 20 nm, it is advantageous in terms of color reproduction and color purity, but it is technically difficult to manufacture, and it is preferable in that the yield decreases through repeated purification processes, and the amount of waste solvent generated rapidly increases, thus reducing economic efficiency. However, if it exceeds 30 nm, there may be a problem in that the color reproduction rate and color purity are lowered.

In addition, the quantum dot particles that do not contain cadmium preferably have a half width of 35 to 50 nm. If the half width of the quantum dot particle is less than 35 nm, it is advantageous in terms of color reproduction and color purity, but it is technically difficult to manufacture, and it is preferable in that the yield decreases through repetitive purification processes, and the amount of waste solvent generated rapidly increases, thus reducing economic efficiency. However, if it exceeds 50 nm, a problem of lowering the color reproduction rate and color purity may occur.

Quantum dot particles containing 5 or more to less than 35% by weight of cadmium are characterized by green light emission, and the average particle diameter is preferably 2 to 4 nm. If the average particle diameter is out of the above range, green light emission cannot be characterized.

The quantum dot particles that do not contain cadmium are characterized by red light emission, and the average particle diameter is preferably 5 to 7 nm. If the average particle diameter is outside the above range, red light emission cannot be characterized.

Quantum dot particles containing 5 or more to less than 35% by weight of cadmium are 0.1 to 4.5 moles, more preferably 0.2, of at least one selected from Group II elements and III elements other than cadmium, based on 1 mole of cadmium. To 4 moles, and 0.5 to 6.0 moles, more preferably 1.0 to 5.0 moles, of at least one selected from a group V element and a group VI element.

If at least one selected from the group II and III elements other than cadmium is less than the above-described range, the cadmium content may increase and environmental problems may occur, and if it exceeds the above range, the color reproduction rate of the quantum dot particles and Color purity cannot be guaranteed, and quantum yield may be lowered.

If at least one selected from the group V element and the group VI element is included in the above-described range, the storage stability of the quantum dot particles decreases, and the quantum efficiency decreases with time, and exceeds the above-described range. In this case, the stability is guaranteed, but the initial quantum efficiency decreases and the half value width increases.

At least one selected from group II and III elements other than cadmium may be selected from the group consisting of zinc (Zn), mercury (Hg), indium (In), magnesium (Mg) and aluminum (Al). And, among these, zinc (Zn) may be preferably used.

At least one selected from the group V element and the group VI element is from the group consisting of phosphorus (P), arsenic (As), quality (N), sulfur (S), selenium (Se), and tellurium (Te). It may be selected, among these, it may be preferable to be selected from sulfur (S) and selenium (Se).

Quantum dot particles that do not contain cadmium included in the quantum dot layer are 1 selected from group V elements and VI elements based on 1 mole of at least one selected from group II elements and III group elements excluding cadmium (Cd). Contains more than 0.2 to 4.0 moles of species.

If at least one selected from the group V element and the group VI element is included in the above-described range, the storage stability of the quantum dot particles decreases, and the quantum efficiency decreases with time, and exceeds the above-described range. In this case, stability is guaranteed, but there may be a problem that the initial quantum efficiency decreases and the half value width increases.

At least one selected from group II elements and group III elements excluding cadmium (Cd) may be selected from zinc (Zn) and indium (In), and at least one selected from the group V and VI elements Silver may be selected from sulfur (S), selenium (Se), tellurium (Te), and phosphorus (P).

In particular, at least one selected from group II and III elements excluding cadmium (Cd) is indium (In), and at least one selected from the group V and VI elements is phosphorus (P). It can be preferably used.

The quantum dot layer may have a cadmium content of 400 to 3000 ppm, more preferably 500 to 2600 ppm.

The quantum dot layer may have a thickness of 20 to 100 μm, preferably 40 to 80 μm. When the thickness of the quantum dot layer is less than the above range, it is difficult to express color purity and color reproducibility, and when the thickness of the quantum dot layer exceeds the above range, cadmium content increases, luminance may decrease, and economy is poor.

The light conversion film includes a first transparent support layer formed on the upper surface of the quantum dot layer and a second transparent support layer formed on the lower surface, and the thicknesses of the first transparent support layer and the second transparent support layer are each independently 50 to 150 μm, more preferably May be 80 to 125 μm, even more preferably 80 to 100 μm. If the thickness of the first transparent support layer and the second transparent support layer is less than the above thickness, the quantum dot layer cannot be sufficiently protected, so the efficiency and color purity of the quantum dot may be continuously decreased. As a result, the appearance of the film may be deteriorated, and if it exceeds the above range, the total transmittance may decrease and the quantum dot efficiency of the quantum dot photo-conversion film may decrease, the total thickness of the liquid crystal display may increase, and the economy may decrease. have.

The light conversion film may have a luminance of 700 cd/m ² or more, preferably 730 cd/m ² or more, and more preferably 750 cd/m ² or more.

The light conversion film may have a color reproduction rate of 100% or more, preferably 110% or more, and more preferably 115% or more.

The light conversion film of the present invention

As a photoconversion film having a thickness of 200 to 280 μm, comprising a first transparent support layer formed on the upper surface of the quantum dot layer and a second transparent support layer formed on the lower surface,

The quantum dot layer has a thickness of 40 to 80 μm,

The thickness of the first transparent support layer and the second transparent support layer are each independently 80 to 100 μm,

The cadmium content of the film is 10 to 60 ppm,

The film having a luminance of 760 cd/m ² or more and a color reproducibility of 115% or more may be more preferably used.

The matrix material may include at least one (meth)acrylate-based compound and at least one photoinitiator.

The (meth)acrylate-based compound is selected from the group consisting of (meth)acrylated monomers, urethane (meth)acrylate oligomers, polyester (meth)acrylate oligomers, and epoxy (meth)acrylate oligomers. More than one type may be used.

The matrix material may further include a polythiol-based compound.

The content of the matrix material will be described in more detail below.

In addition, the present invention

It relates to a backlight unit for a display device including the light conversion film.

The backlight unit for the display device may include a light guide plate, a reflective plate disposed under the light guide plate, a plurality of light-emitting elements disposed on one side of the light guide plate, a light conversion film disposed on the light guide plate, and a luminance enhancing film disposed on the light conversion film. I can.

The light emitting device may be a blue light emitting diode.

The backlight unit for the display device will be described in more detail below.

In addition, the present invention

It relates to a display device including the display unit.

The display device is not particularly limited, but may be a liquid crystal display device. The display device will be described in more detail below.

In addition, the present invention

(a) 0.4 to 2% by weight of cadmium-containing quantum dot particles having a cadmium (Cd) content of 5 to less than 35% by weight;

(b) 0.05 to 0.75% by weight of quantum dot particles not containing cadmium;

(c) 75 to 98% by weight of the matrix material; And

(d) 0.1 to 10% by weight of a scattering agent; containing

It relates to a composition for forming a quantum dot layer.

The content of the invention constituting the composition for forming the quantum dot layer may be applied in all ranges applicable to the above-described quantum dot layer.

The matrix material may preferably include one or more (meth)acrylate-based compounds, polythiol-based compounds, and one or more photoinitiators.

The matrix material may preferably include 30 to 70 parts by weight of a (meth)acrylate compound, 10 to 50 parts by weight of a polythiol compound, and 1 to 6 parts by weight of one or more photoinitiators.

The composition for forming a quantum dot layer may have a cadmium content of 400 to 3000 ppm, more preferably 500 to 2,600 ppm.

Examples of the (meth)acrylate-based compound include isobornyl (meth)acrylate, ethylhexyl (meth)acrylate, lauryl (meth)acrylate, octyldecyl (meth)acrylate, isooctyl (meth)acrylate, At least one selected from the group consisting of trimethylcyclohexyl (meth)acrylate, isodecyl (meth)acrylate, stearic (meth)acrylate, and tricyclodecane dimethanol di (meth)acrylate, etc. will be used. I can.

The (a) quantum dot particles containing cadmium (Cd) content of 5 or more to less than 35% by weight are green light emitting particles, have a maximum absorption wavelength of 525 to 540 nm, a half width of 20 to 30 nm, and a quantum yield of 90% To 99%, and (b) the quantum dot particles not containing cadmium are red light emitting particles, the maximum absorption wavelength is 625 to 640 nm, the half width is 35 to 50 nm, and the quantum yield is more preferably 70% to 85% Can be used.

The composition for forming the quantum dot layer will be described in more detail below.

In addition, the present invention

(a) 0.1 to 4.5 moles of a cation precursor containing at least one selected from a group II element and a group III element not containing cadmium (Cd) per 1 mole of the cation precursor containing cadmium (Cd), and V Reacting 0.5 to 6.0 moles of an anion precursor containing at least one selected from a group element and a group VI element; And

(b) separating the particles generated in the step (a); it relates to a method for producing quantum dot particles containing 5 or more to less than 35% by weight of cadmium.

In addition, the present invention

(a) 0.1 to 4.5 moles of a cation precursor containing at least one selected from a group II element and a group III element not containing cadmium (Cd) per 1 mole of the cation precursor containing cadmium (Cd), and V Reacting 0.5 to 6.0 moles of an anion precursor containing at least one selected from a group element and a group VI element;

(b) separating and drying the particles generated in step (a) to prepare quantum dot particles having a cadmium content of 5 to 35% by weight; And

(c) dispersing the quantum dot particles having a cadmium content of 5 to 35% by weight in a solvent or a compound containing a double bond at a concentration of 1 to 20% by weight;

It relates to a method for producing a dispersion of quantum dot particles comprising a.

It is preferable that the cadmium content of the quantum dot particle dispersion is 0.1 to 7.0% by weight.

The contents described below can be applied to the method of manufacturing the quantum dot particle and the method of manufacturing a dispersion of the quantum dot particle.

The cation precursors containing cadmium (Cd) include dimethyl cadmium, diethyl cadmium, cadmium oxide, cadmium carbonate, cadmium acetate dihydrate. , Cadmium acetylacetonate, cadmium fluoride, cadmium chloride, cadmium iodide, cadmium bromide, cadmium perchlorate, cadmium Phosphide (cadmium phosphide), cadmium nitrate (cadmium nitrate), cadmium sulfate (cadmium sulfate), cadmium carboxylate (cadmium carboxylate), and at least one selected from the group consisting of cadmium oleate (cadmium oleate) to be used. I can.

The precursor containing at least one selected from a group II element and a group III element that does not contain cadmium (Cd) may be added to the reaction in an amount of 0.1 to 4.5 mol, preferably 0.2 to 4.0 mol. If the amount of the cation precursor containing at least one selected from the group II element and the group III element not containing cadmium (Cd) is less than the above-described range, the cadmium content may increase, thereby causing environmental problems. If it exceeds the range, the color reproduction rate and color purity of the quantum dot particles cannot be guaranteed, and the quantum yield may be lowered.

The anion precursor including at least one selected from the group V element and the group VI element may be added to the reaction in an amount of 0.5 to 6.0 mol, preferably 1.0 to 4.0 mol. When the anion precursor containing at least one selected from the group V and VI elements is added in an amount less than the above-described content, the storage stability of the quantum dot particles decreases, resulting in a problem that the quantum efficiency decreases over time. In addition, when added in excess of the above-described content, stability is guaranteed, but the initial quantum efficiency decreases and the half value width increases.

The manufacturing method will be described in detail below.

<Display device>

Hereinafter, a liquid crystal display device will be described as an example.

1 is a diagram schematically showing a structure of a liquid crystal display device 1. The liquid crystal display device 1 includes a liquid crystal display panel 100, a pair of polarizing films 11 and 12 disposed above and below the liquid crystal display panel 100, and a backlight unit 200.

The liquid crystal display panel 100 includes a lower panel 13 and an upper panel 14 and a liquid crystal layer 10 sandwiched between the two display panels 13 and 14. The lower display panel 13 may include a transparent substrate, a thin film transistor that is formed on the substrate through a thin film process, and switches voltage application to the pixel electrode, and a pixel electrode connected to the thin film transistor. The upper display panel 14 may include a transparent substrate, a light blocking layer and a color filter formed on the transparent substrate, a planarization layer formed to cover the light blocking layer and the color filter, a common electrode formed to cover the planarization layer, and the like. . The pixel electrodes are formed at positions corresponding to each color filter.

The backlight unit 200 includes a light-emitting element that emits blue light or ultraviolet light and a photoconversion layer that converts blue light or ultraviolet light into white light including quantum dots. The backlight unit 200 serves as a light source that supplies light to the liquid crystal display device.

The light supplied from the backlight unit 200 is linearly polarized by the lower polarizing film 11, and the phase of the linearly polarized light is selectively changed while passing through the liquid crystal layer 10. Light passing through the liquid crystal layer 10 is filtered into red, green, and blue light while passing through the color filter to reach the upper polarizing film 12, and the upper polarized light according to the degree of phase change in the liquid crystal layer 10. The amount of light transmitted through the film 12 varies. The amount of light transmitted through the upper polarizing film 12 can be controlled by adjusting the voltage applied to each of the pixel electrodes, and thus the amount of red, green, and blue light transmitted through the upper polarizing film 12 can be independently controlled. I can. The liquid crystal display device may display a color image through this process. In this case, the color gamut displayed by the liquid crystal display device is determined according to the color purity of red, green, and blue light components of white light supplied from the backlight unit 200. That is, since the white light supplied by the backlight unit 200 is filtered by the color filter to extract red, green, and blue light and use it for display, the red light, green light, and blue light included in the white light supplied by the backlight unit 200 The color purity that can be displayed by the liquid crystal display device is diversified when the color purity is high, and thus a wide color gamut can be displayed.

The white light supplied by the backlight unit 200 includes a red light component, a green light component, and a blue light component. The white light supplied from the backlight unit 200 passes through a red filter to extract a red component, a green filter is passed to extract a green component, and a blue filter is passed through a blue component to extract a color coordinate corresponding to each color component. By drawing a triangle with the position of the image as each vertex, you can get the triangle color area defined above. When the backlight unit 200 is combined with the liquid crystal display panel 100 to form a liquid crystal display device and the spectrum is measured, the measurement can be performed using a color filter formed in the liquid crystal display panel 100.

The red spectrum is obtained by measuring only the red pixel of the liquid crystal display device with the red pixel turned on and the remaining pixels turned off, the green spectrum is obtained by measuring with only the green pixel turned on and the remaining pixels turned off, and the measurement with the blue pixel turned on and the remaining pixels turned off. A blue spectrum can be obtained. Alternatively, the spectrum of the white light emitted by the backlight unit 200 may be measured using a spectroscope, and the position on the color coordinates of each color component may be calculated using the peak wavelength and half width of the measured spectrum. Here, since the blue light component is generally light emitted by the blue light emitting diode, it is determined according to the characteristics of the blue light emitting diode, and there may be little room for change. Therefore, there is an advantage of considering only the characteristics of the red light component and the green light component.

The backlight unit 200 includes a light guide plate 22, a reflective plate 20 disposed under the light guide plate 22, a light-emitting element 21 disposed on one side of the light guide plate 22, and a light guide plate 22. It may include a light conversion film 23. In addition, a luminance enhancing film 24 and a reflective polarizing plate 25 may be included on the light conversion film 23. The light guide plate 22 serves to convert light (point light source) generated from the light emitting element 21 to the front of the backlight and convert it into a surface light source. The light guide plate 22 may optionally be an inclined type light guide plate whose thickness gradually decreases in the opposite direction from the vicinity of the light emitting element 21 or a general type light guide plate having the same thickness, and the light guide plate 22 is a polymer composite having high transmittance and excellent heat resistance. For example, polymethyl meta acrylate resin (PMMA), polycarbonate resin (PC), polyethylene telephthalate resin (PET) can be selected and manufactured by melt extrusion method. In addition, the reflective plate 20 disposed under the light guide plate 22 may be used to reduce light loss by reflecting and raising the light emitted from the light emitting element 21 to the lower side of the backlight. As mentioned above, the light-emitting element 21 is preferably a blue light-emitting diode, and the blue light-emitting diode is converted into a red light component and a green light component while passing through the photoconversion film 23 , It has the advantage of increasing color purity. Light passing through the light conversion film 23 may pass through the luminance improving film 24 to increase luminance. The luminance enhancing film 24 serves to condense light by producing a cured layer having a high refractive index on a transparent support layer in a prism shape, and can increase energy efficiency.

<Light conversion film>

2 is a diagram schematically showing an embodiment of the light conversion film 23 of the present invention. In the present invention, the light conversion film 23 may be, for example, a quantum dot layer formed in the first transparent support layer 30 and the second transparent support layer 31, but is not limited thereto. The quantum dot layer 40 includes a matrix material 40 that is a curable material, a quantum dot particle 41 containing 5 to less than 35 wt% cadmium, a quantum dot particle 42 not containing cadmium, and a scattering agent 43. It characterized in that it is produced by curing a material consisting of a mixture. The total thickness of the light conversion film may be determined according to the thickness of the first transparent support layer, the second transparent support layer, and the quantum dot layer of the light conversion film 23. Preferably it may be 120 to 400μm, more preferably 150 to 350μm. If the above range is exceeded, the design design may be limited due to the thick thickness of the backlight unit, and the overall luminance may be lowered by falling from the transmittance, and if it is less than the above range, the durability decreases, making it difficult to continuously maintain the light conversion role, or Deformation may occur due to heat generated from the backlight unit, and wrinkles may be visually recognized or distortion of the display screen may occur. Hereinafter, the components of the light conversion film of the present invention will be described.

(1) the first transparent support layer and the second transparent support layer

As the first transparent support layer and the second transparent support layer, high transparency is required, and a film-type substrate having excellent heat resistance is used. Examples of the film-type substrate include polyesters such as poly(meth)acrylate, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polyarylate; Polycarbonate, polyvinyl chloride, polyethylene, polypropylene, polystyrene, aliphatic or aromatic polyamide (e.g., nylon, aramid, etc.), polyetheretherketone, polysulfone, polyethersulfone, polyimide, polyamideimide, polyetherimide , A cyclic olefin polymer (COP), a film including a resin such as polyvinylidene chloride, but is not limited thereto.

In addition, as the first transparent support layer and the second transparent support layer, a film-type substrate subjected to a separate surface treatment may be used. Nano-sized quantum dots are susceptible to external factors such as moisture or oxygen and have a short lifespan, so when the quantum dot layer is applied to a light emitting diode or a quantum dot photoconversion film, passivation of the quantum dot surface is required to ensure the efficiency and color purity of the quantum dot. It is important to keep the layers. Accordingly, in addition to the first transparent support layer and the second transparent support layer, a barrier film (coating) for protecting the quantum dots of the quantum dot layer from an external environment (eg, moisture or oxygen) may be further formed. The barrier film (coating) may be, for example, a vapor-deposited metal oxide layer formed by sputtering or the like.

(2) quantum dot layer

In the present invention, the quantum dot layer is, for example, after coating a composition for forming a quantum dot layer on at least one surface of the first transparent support layer or the second transparent support layer, and laminating the first transparent support layer or the second transparent support layer, It may be prepared by curing by heat or ultraviolet rays, and the composition for forming a quantum dot layer may include the following (A) to (D).

(A) quantum dot particles containing 5 or more to less than 35% by weight of cadmium

(B) quantum dot particles that do not contain cadmium

(C) matrix material

(D) a scattering agent having a particle size of 0.01 to 10 μm

The composition for forming a quantum dot layer may be uniformly dispersed and prepared through a known mixing process. Mixing the compounds of (A) to (D) at a stirring speed of 100 to 1000 rpm in a dispersion equipment equipped with ITT (Intensive Type with Teeth) Dispersion Blade, using a filter of 5 microns or less, preferably a filter made of Teflon By doing so, you can get rid of large particles.

In order to minimize the dispersion of particles and the amount of large particles of the composition for forming the quantum dot layer, an additional dispersant may be added. Dispersants are commercially available dispersants such as DisperBYK-111, DisperBYK-110, DisperBYK-161, DisperBYK-162, DisperBYK-170, DisperBYK-181, DisperBYK-2000, DisperBYK-2009, DisperBYK-2200, Evonik WET-250, WET-260, WET-270, WET-280 from BASF, Efka® PU 4010 from BASF, Efka® PU 4015, Efka® PU 4046, Efka® PU 4050, Efka® PU 4055, Efka® PU 4063, Efka ® PU 4080, Efka® PX 4300, Efka® PX 4330, Efka® PX 4350, Efka® PX 4700 can be purchased and used in one or more groups.

(A) quantum dot particles containing 5 or more to less than 35% by weight of cadmium used in the composition for forming a quantum dot layer and (B) quantum dot particles not containing cadmium are 1 to 1 in a solvent or a compound containing a double bond It is preferable to use it by dispersing in 20% by weight. It is preferable to obtain the quantum dot particles by a method of purifying through precipitation using a non-solvent. However, if the particles are stored in a dry state, there is a problem that the stability is lowered and the quantum yield is lowered.If the dried quantum dots are directly added to the composition for forming a quantum dot layer, a phenomenon of agglomeration of the quantum dot particles may occur. Since it is difficult to secure a problem, a problem occurs only when the amount of quantum dot particles is increased. In the present invention, in order to solve this problem, it is proposed to disperse the dried quantum dot particles in a solvent or a compound containing a double bond in an amount of 1 to 20% by weight to store and apply to the composition for forming the quantum dot layer. The quantum dot particles used in the present invention may contain a saturated or unsaturated aliphatic compound containing an aliphatic alkyl on the surface (the alkyl is a straight chain or branched chain having the number of carbon atoms indicated below), and in order to disperse it, a hydrophobic solvent Or it is preferable to disperse in a compound containing a hydrophobic double bond. The hydrophobic solvent is preferably an aromatic hydrocarbon solvent such as benzene, toluene, and xylene, and an aliphatic hydrocarbon solvent such as hexane, heptane and octane. However, when the quantum dot particles dispersed in a solvent are mixed with the composition for forming the quantum dot layer, the composition for forming the quantum dot layer is cured only after removing the solvent through a process for removing a separate solvent, for example, a high-temperature distillation process. After the process, problems such as adhesion, appearance, and brightness of the light conversion film do not occur.

Therefore, in order to avoid the process of removing the solvent through a high-temperature vacuum distillation process, etc., a compound including a hydrophobic double bond as a compound capable of curing reaction with the matrix layer, for example, a hydrophobic (meth)acrylate-based compound It is good to use a compound to disperse the quantum dot particles.

Examples of the hydrophobic (meth)acrylate-based compound include isobornyl (meth)acrylate, ethylhexyl (meth)acrylate, lauryl (meth)acrylate, octyldecyl (meth)acrylate, isooctyl (meth)acrylic At least one selected from the group consisting of acrylate, trimethylcyclohexyl (meth)acrylate, isodecyl (meth)acrylate, stearic (meth)acrylate, tricyclodecane dimethanol di (meth)acrylate, etc. It is good to disperse in.

Through the curing process of the composition for forming the quantum dot layer, a quantum dot layer having a thickness of 20 to 100 μm, preferably 40 to 80 μm may be formed. The thickness of the quantum dot layer may be adjusted by the amount of the composition for forming the quantum dot layer, the viscosity of the composition for forming the quantum dot layer, and the laminating pressure applied when laminating the first transparent support layer or the second transparent support layer.

(2-1) quantum dot particles

Quantum dots can contain a core, a shell and a ligand. Quantum dots, for example, may have a size of about 10 nm or more, and may have a high quantum efficiency proportionally.

The core may have a three-dimensional shape such as a substantially spherical shape at the center of the quantum dot, and may include at least one cation and at least one anion. The cation may include a group II element or a group III element, and may include, for example, cadmium (Cd), zinc (Zn), and indium (In). The anion may include a group V element or a group VI element, and may include, for example, sulfur (S), selenium (Se), tellurium (Te), and/or phosphorus (P). Accordingly, the core is a binary core containing CdSe, CdTe, CdS, ZnSe, ZnTe, InP, etc., a ternary core containing ZnCdS, ZnSeTe, CdSeS, ZnCdSe, ZnCdTe, etc. It may be a containing four-component core.

Meanwhile, the core may exhibit various colors according to its composition ratio, that is, the contents of the cation and/or the anion. Accordingly, the quantum dots may have various emission colors such as blue, red, and green. Typically, the quantum dot may be a blue quantum dot or a green quantum dot.

The shell may substantially surround the surface of the core, and may include at least one cation and at least one anion. The cation may include, for example, a group II element such as zinc (Zn) and cadmium (Cd). The anion may include, for example, a group VI element such as sulfur (S) and seledium (Se). The shell may be a binary shell containing ZnS, ZnSe, or the like, or a ternary shell containing ZnCdS, ZnCdSe, or the like. The shell may have a layered gradient composition. That is, the shell may have different anion contents and/or different cation contents from the innermost layer to the outermost layer thereof. For example, when the shell contains zinc (Zn), cadmium (Cd) and sulfur (S), the concentration of zinc (Zn) inside the shell may be substantially lowest in its innermost layer, and substantially lowest in the outermost layer. Can be the highest. That is, the zinc (Zn) concentration inside the first shell may substantially increase as the distance from the core increases. The shell may have a certain composition, for example, the cation content and/or the anion content uniform from the innermost layer to the outermost layer thereof. Meanwhile, the quantum dot may further include a second shell that substantially surrounds the surface of the shell. In this case, the size of the quantum dot may be further increased, and in particular, bonding between electrons and holes inside the core may be further protected. In addition, accordingly, the quantum dot can have a higher quantum efficiency, and can continuously maintain it.

The ligand may contain, for example, an organic functional group, and chemically bonded to the shell surface by the organic functional group. However, it is not limited thereto. The ligand may be introduced to the surface of the quantum dot particle through a ligand exchange reaction of a compound containing a group II element used during the shell manufacturing process, and the structure of the organic functional group of the ligand is closely related to compatibility with the matrix resin. .

(2-2) Quantum dots containing 5 or more to less than 35% by weight of cadmium

Quantum dots having a cadmium content of 5 to less than 35% by weight may be prepared using at least one cation precursor and at least one anion precursor.

The at least one cation precursor is 0.1 to 4.5 moles of a precursor containing at least one selected from a group II element and a group III element not containing cadmium (Cd) per 1 mole of the cation precursor including cadmium (Cd) , Preferably 0.2 to 4.0 moles.

When the content of the cation precursor containing at least one selected from the group II element and the group III element that does not contain cadmium (Cd) is used below the above range, the cadmium content may increase, thereby causing environmental problems, and the above range When used in excess of, the color reproduction and color purity of the quantum dot particles cannot be guaranteed, and the quantum yield may be lowered.

At least one selected from the group II element and the group III element may be selected from, for example, zinc (Zn), mercury (Hg), indium (In), magnesium (Mg) and aluminum (Al), The use of zinc (Zn) may be preferable in terms of core manufacturing and physical properties of the core.

The cation precursors containing cadmium (Cd) include dimethyl cadmium, diethyl cadmium, cadmium oxide, cadmium carbonate, cadmium acetate dihydrate. , Cadmium acetylacetonate, cadmium fluoride, cadmium chloride, cadmium iodide, cadmium bromide, cadmium perchlorate, cadmium force Pide (cadmium phosphide), cadmium nitrate (cadmium nitrate), cadmium sulfate (cadmium sulfate), cadmium carboxylate (cadmium carboxylate), cadmium oleate (cadmium oleate), and the like, and select one or more of them. Can be used.

Cationic precursors containing at least one selected from the group II element and group III element not containing cadmium (Cd) include zinc acetate, dimethylzinc, diethyl zinc, Zinc carboxylate, zinc acetylacetonate, zinc iodide, zinc bromide, zinc chloride, zinc fluoride, zinc Carbonate (zinc carbonate), zinc cyanide (zinc cyanide), zinc nitrate (zinc nitrate), zinc oxide (zinc oxide), zinc peroxide (zinc peroxide), zinc perchlorate (zinc perchlorate), zinc sulfate (zinc sulfate) , Zinc oleate, mercury iodide, mercury bromide, mercury fluoride, mercury cyanide, mercury nitrate, mercury Perchlorate, mercury sulfate, mercury oxide, mercury carbonate, mercury carboxylate, aluminum phosphate, aluminum acetylacetonate ), aluminum chloride, aluminum fluoride, aluminum oxide, aluminum nitrate, aluminum sulfate , Gallium acetylacetonate, gallium chloride, gallium fluoride, gallium oxide, gallium nitrate, gallium sulfate, indium chloride (gallium acetylacetonate), gallium chloride (gallium chloride), gallium fluoride, gallium oxide, gallium nitrate, gallium sulfate, indium chloride indium chloride), indium oxide, indium nitrate, indium sulfate, indium acetate, indium carboxylate, and precursor compounds based on the precursors One or more selected from the group consisting of may be used.

At least one selected from the group II element and the group III element may be prepared through a ligand exchange reaction to form an appropriate precursor. The compound that can be used as the ligand may be, for example, a monovalent alkyl carboxylic acid compound, and the alkyl is a linear or branched chain, saturated or unsaturated chain having the number of carbon atoms indicated below. It may be an aliphatic compound. The alkyl is an alkyl having 5 to 25 carbon atoms, and more preferably may be an alkyl having 10 to 20 carbon atoms. Specifically, at least one selected from the group consisting of lauric acid, palytic acid, tritecylic acid, mystic acid, steric acid, pentadecylic acid, oleic acid, and the like may be used.

The ligand exchange reaction may include, for example, mixing and dissolving the group II element and/or the group III element and the alkyl carboxylic acid compound (90 to 120° C.); Increasing the temperature to proceed with a ligand exchange reaction (140 to 170°C); It may comprise the step of removing the by-products generated by the ligand exchange reaction with high vacuum.

The at least one anion precursor may be an anion precursor including at least one selected from a group V element and a group VI element. Specifically, the group V element may be, for example, phosphorus (P), arsenic (As) or nitrogen (N), and the group VI element, for example, sulfur (S), selenium (Se), or It may be tellurium (Te) or the like.

Group V cationic precursors containing the group V element include alkyl phosphine, tristrialkylsilyl phosphine (tris (trialkylsilyl phosphine)), tris dialkylsilyl phosphine (tris (dialkylsilyl phosphine)), tris Dialkylamino phosphine (tris), arsenic oxide, arsenic chloride, arsenic sulfate, arsenic bromide, arsenic iodide (arsenic iodide), nitric oxide (nitric oxide), nitric acid (nitric acid), it may be one or more selected from the group consisting of ammonium nitrate (ammonium nitrate).

In addition, as Group VI cationic precursors containing the Group VI element, sulfur, trioctylphosphine sulfide, trialkylphosphine sulfide, trialkenylphosphine sulfide, trialkenylphosphine sulfide ), alkylamino sulfide, alkenylamino sulfide, alkylthiol, trioctylphosphine selenide, trialkylphosphine selenide, trialkylphosphine selenide Alkenylphosphine selenide, alkylamino selenide, alkenylamino selenide, trialkylphosphine telluride, trialkenylphosphine telluride, trialkenylphosphine telluride), alkylamino telluride (alkylamino telluride), alkenylamino telluride (alkenylamino telluride), and the like, and one or more selected from the group consisting of precursor compounds based on the precursors may be used.

In the present invention, the cadmium-containing quantum dots

(a) preparing a solution comprising a core comprising at least one cation precursor and at least one anion precursor;

(b) preparing a compound to be used in a shell including particles and an organic solvent including at least some of the elements constituting the cation precursor and the anion precursor included in the core; And

(c) injecting a solution containing the prepared core into a solution containing a compound to be used in a high-temperature shell to form quantum dot particles.

More specifically, preparing a first solution including at least one cation precursor and a second solution including at least one anion precursor; Preparing a solution including a core by mixing the first solution and the second solution; Preparing a solution containing a compound to be used in a shell including particles and an organic solvent containing at least some of the elements constituting the cation precursor and the anion precursor included in the core; Gradually heating the solution containing the compound to be used in the shell to 200 to 350°C; And injecting a solution containing a core into a solution containing a compound to be used in the heated shell within 0.1 to 5 minutes.

In the following, each step will be described in more detail.

A first solution including at least one cation precursor and a second solution including at least one anion precursor are prepared. At this time, the first solution is 1 selected from at least two or more precursors, that is, one or more cationic precursors including cadmium (Cd) among the group II elements, and group II elements and group III elements not including cadmium (Cd). It contains one or more kinds of precursors containing more than one species.

The first solution is 0.1 to 4.5 moles of a precursor containing at least one selected from a group II element and a group III element not containing cadmium (Cd) per 1 mole of the cation precursor containing cadmium (Cd) , Preferably, 0.2 to 4.0 mol can be used to adjust the cadmium (Cd) content in the quantum dot particles. The first solution includes two or more cation precursors including a cation precursor including cadmium (Cd), and the second solution may also include two or more anion precursors, but is not limited thereto. In at least one selected from a group II element and a group III element that do not contain cadmium (Cd) in the cation precursor, the group II element may be selected from zinc (Zn) and mercury (Hg), and a group III element May be selected from indium (In), magnesium (Mg) and aluminum (Al). In particular, zinc (Zn) may be preferably used as at least one selected from a group II element and a group III element.

The anion precursor may be a precursor including at least one selected from a group V element and a group VI element. Specifically, the group V element may be selected from phosphorus (P), arsenic (As), and quality (N), and the group VI element is from sulfur (S), selenium (Se), and tellurium (Te). Can be chosen.

The step of preparing the first solution may include mixing the first cation precursor, the second cation precursor, and the saturated/unsaturated fatty acid to form an appropriate cation precursor, and then raising the temperature; Removing by-products by vacuum; And it may include performing a ligand exchange reaction.

In an embodiment of the present invention, in order to prepare a first solution containing zinc oleate and cadmium oleate, mixing zinc acetate, cadmium oxide and oleic acid, and raising the temperature to 100 to 160°C; Performing a ligand exchange reaction at 140 to 180°C; Removing the low molecular weight acid generated by the ligand exchange reaction with high vacuum; can be carried out.

Next, a solution including a core is prepared by mixing the first solution and the second solution. Specifically, a reaction may be performed between a first solution containing a cation precursor and a second solution containing an anion precursor at 200 to 400°C. More preferably, the reaction may proceed at 250 to 350°C. The composition ratio of the first solution and the second solution in the mixed solution may be appropriately adjusted according to the emission wavelength of the finally formed quantum dot. For example, the molar ratio of the first solution and the second solution may be 1:4 to 4:1, but is not limited thereto.

When preparing the mixed solution containing the core, an organic solvent may be used. An organic solvent capable of mixing the cation precursor of the first solution and the anion precursor of the second solution is used. Examples of such organic solvents include primary alkylamines having 6 to 22 carbon atoms such as hexadecylamine, secondary alkylamines having 6 to 22 carbon atoms such as dioctylamine, tertiary alkylamines having 6 to 40 carbon atoms such as trioctylamine, Nitrogen-containing heterocyclic compounds such as pyridine, aliphatic hydrocarbons having 6 to 40 carbon atoms such as hexadecane, octadecane, octadecene, and squalene (alkanes, alkenes, alkynes, etc.), phenyldodecane, phenyltetradecane, phenyl hexa Aromatic hydrocarbons having 6 to 30 carbon atoms such as decane, phosphine substituted with an alkyl group having 6 to 22 carbon atoms such as trioctylphosphine, phosphine oxide substituted with an alkyl group having 6 to 22 carbon atoms such as trioctylphosphine oxide, phenyl It may be any one of aromatic ethers having 12 to 22 carbon atoms, such as ether and benzyl ether, and combinations thereof, but is not limited thereto.

The organic solvent is decompressed at about 100 to 150°C, undergoes a water removal process, and then heated at 200 to 350°C.

Through the above reaction, the elements of the cation precursor and the anion precursor are combined to form a quantum dot having an alloy form. In the method of manufacturing a quantum dot of the present invention, since one solution contains at least two or more precursors, and the second solution contains at least one or more precursors, a core of quantum dot particles containing a total of three or more elements is formed. do. The quantum dot manufactured by the manufacturing method of the present invention may have a single core shape including three or more elements such as Zn-Cd-S, Zn-Cd-Se, and Zn-Cd-S-Se, but is not limited thereto. . At this time, the optical density, half width, etc. may vary depending on the amount of the precursor containing Cd. Finally, the product formed from the core is cooled and purified. Specifically, the resultant quantum dot formed through the reaction step is first cooled to room temperature, and then purified and washed to obtain a core of quantum dot particles having a desired purity. Purification may include the step of separating the core of the quantum dot particles by adding a nonsolvent to the resulting product. Non-solvent is mixed with the organic solvent used in the reaction, but is a polar solvent that cannot disperse the quantum dots.Acetone, ethanol, butanol, isopropanol, ethanol, water, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), di It may be ethyl ether, formaldehyde, etc., but is not limited thereto. In addition, purification may include separating the quantum dots through a method such as centrifugation, precipitation, chromatography, or distillation.

The core alloy may secure sufficient stability even if it does not include a separate shell structure, but may include a shell structure according to a maximum emission spectrum determined by conditions of use or particle size. However, it is not essential.

In order to manufacture a quantum dot having a core-shell structure, a manufacturing method including a step-by-step synthesis process may be used to first form the core and then secondly form the shell.

In the shell formation, a cation precursor and an anion precursor used to construct the core may be used at the same time. The cation precursor is preferably a compound that does not contain cadmium (Cd) element. When a compound containing a cadmium (Cd) element is used, the cadmium (Cd) content of the quantum dot particles increases, and environmental problems may occur. As in the case of manufacturing the core, a group II element or a group III element that does not contain cadmium (Cd), for example, zinc (Zn), mercury (Hg), indium (In), magnesium (Mg) or aluminum (Al) Although a precursor containing may be used, it is preferable to use a precursor containing zinc (Zn) in consideration of the properties or manufacturing convenience of the quantum dot particles. The cation precursor may be prepared through a ligand exchange reaction in the same manner as in the production of the core. Mixing the cation precursor and the saturated/unsaturated fatty acid, and then raising the temperature, removing the by-product by vacuum, and a ligand exchange reaction may be further included.

The anion precursor may be a precursor including at least one selected from a group V element and a group VI element in the same manner as the core preparation. Specifically, the group V element may be selected from phosphorus (P), arsenic (As) or nitrogen (N), and the group VI element may be selected from sulfur (S), selenium (Se), and tellurium (Te). I can.

The cation precursor and the anion precursor may be added at the same time to form a shell structure in the form of an alloy, or may be separately added to give a gradient to the shell, but is not limited thereto.

A ligand capable of improving compatibility with a matrix material may be additionally introduced to the surface of the prepared core or the quantum dot particle having a core/shell structure, but the cation precursor used in the manufacture of the core and shell Since the ligand can bind to the surface of the quantum dot particle, it is not an essential process. This may be appropriately changed through a ligand exchange reaction depending on the matrix material, or quantum dot particles may be prepared without a separate ligand exchange process after the shell process.

Nanoparticles containing cadmium having a cadmium content of 5 or more to less than 35% by weight prepared by the above method are preferably CdS/ZnS, CdSe/ZnSe, CdS/ZnSe, CdS/CdSe/ZnS, CdS/CdSe/ZnSe, CdSe /ZnS/ZnSe, CdS/ZnS/ZnSe, and CdS/CdSe/ZnS/ZnSe alloys may be formed, but are not limited thereto.

The quantum dot particles containing cadmium may be nanoparticles having a maximum absorption wavelength in a green wavelength range of 525 to 540 nm, a half width of 20 to 30 nm, and a quantum yield of 90% to 99%. The quantum dot particles in the wavelength band have a relatively small particle size so that the amount of cadmium can be reduced to a minimum, and the quantum dot particles in the wavelength band need to be injected in a relatively large amount into the quantum dot particles, which is the advantage of quantum dot particles containing cadmium. It has the advantage of being able to reflect the half-width and high quantum yield as much as possible.

In the present invention, the quantum dot particles containing 5 or more to less than 35% by weight of cadmium are 0.4 to 2 parts by weight, preferably 0.6 parts by weight to 1.5 parts by weight, even more, based on 100 parts by weight of the pre-curing composition of the entire quantum dot layer It is preferably included in an amount of 0.7 parts by weight to 1.0 parts by weight. If it is less than the above range, the color reproducibility and color purity are lowered, and if it exceeds the above range, the cadmium (Cd) content increases, and economical efficiency may decrease.

(2-3) quantum dot particles that do not contain cadmium

The quantum dot particles not containing cadmium may include at least one cation and at least one anion. The cation may include one or more selected from Group II and III elements excluding cadmium (Cd), and may include, for example, zinc (Zn) and/or indium (In). The anion may include at least one selected from a group V element and a group VI element, for example, sulfur (S), selenium (Se), tellurium (Te), and/or phosphorus (P). It may be prepared by a method similar to the method for producing cadmium-containing nanoparticles having a cadmium content of 5 to less than 35% by weight, except for excluding a cation precursor containing a cadmium atom. The quantum dot particles not containing cadmium are preferably InP/ZnS, InP/ZnSe, InP/ZnS/ZnSe alloy type quantum dot particles, but are not limited thereto.

The quantum dot particles not containing cadmium may be nanoparticles having a photoluminescence spectrum having a maximum emission in a red wavelength range of 625 to 640 nm, a half width of 35 to 50 nm, and a quantum yield of 75 to 85%. Since quantum dot particles in the wavelength band have a relatively large particle size, the amount of cadmium is relatively increased when they are manufactured in cadmium form, so it is not preferable to use quantum dot particles containing cadmium. In addition, since the quantum dot particles in the wavelength band are introduced into the quantum dot layer in a relatively small amount, even when quantum dot particles that do not contain cadmium are used, problems of high half width and low quantum yield, which are disadvantages of such quantum dots, can be minimized.

The quantum dot particles not containing cadmium are 0.05 to 0.75 parts by weight, preferably 0.10 parts by weight to 0.45 parts by weight, and even more preferably 0.15 parts by weight to 0.35 parts by weight based on 100 parts by weight of the pre-curing composition of the entire quantum dot layer. Good to include. If it is less than the above range, the color reproducibility and color purity are lowered, and if it is more than the above range, hardness may decrease.

(2-4) matrix material

The matrix material can be used regardless of the liquid composition, as long as it has good compatibility with the core-shell structured quantum dot particles. The matrix material may be included in 75 to 98% by weight, preferably 88 to 98% by weight, based on the total weight of the quantum dot layer.

The liquid composition is preferably a resin that can be cured by ultraviolet rays or heat, and after curing, a resin that can exist as a matrix of a solid quantum dot layer. In particular, considering processability or process convenience, an ultraviolet curing composition may be preferable. The ultraviolet curing composition may include a (meth)acrylate-based compound, a photoinitiator, and an antioxidant in the molecule. In addition, a polythiol-based compound may be used to accelerate curing and reduce cure shrinkage.

The (meth)acrylate-based compound is 1 selected from the group consisting of (meth)acrylated monomers, urethane (meth)acrylate oligomers, polyester (meth)acrylate oligomers, and epoxy (meth)acrylate oligomers. More than one species may be mentioned, but the present invention is not limited thereto, and any (meth)acrylate-based compound commonly used in the art may be used without limitation.

The (meth)acrylated monomer may be prepared by an ester condensation reaction of an aliphatic alcohol and (meth)acrylic acid. Depending on the number of aliphatic alcohols, it may be a monofunctional, bifunctional, trifunctional, tetrafunctional, pentafunctional, or 6functional (meth)acrylate monomer. Representative examples include (meth)acrylic acid, ethylene glycol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate ester, isosorbide di(meth)acrylate, tris(2-hydroxyethyl)isocyanu Rate tri(meth)acrylate and di(meth)acrylate, alkyl of acrylic or methacrylic acid (such as isobornyl, isodecyl, isobutyl, n-butyl, t-butyl, methyl, ethyl, tetrahydrofurfuryl , Cyclohexyl, n-hexyl, iso-octyl, 2-ethylhexyl, n-lauryl, octyl or decyl) ester, hydroxyalkyl (such as 2-hydroxyethyl and hydroxypropyl) ester (meth)acrylate, Phenoxyethyl (meth)acrylate, nonylphenolethoxylate mono (meth)acrylate, 2-(-2-ethoxyethoxy)ethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, Butylene glycol di(meth)acrylate and tri(meth)acrylate, 1,6-hexanediol di(meth)acrylate, ethoxylated and/or propoxylated hexanediol di(meth)acrylate, ethoxylated bisphenol A diacrylate, sorbitol di(meth)acrylate, glycerol tri(meth)acrylate and its ethoxylated and/or propoxylated derivatives, bisphenol A di(meth)acrylate and its ethoxylated and/or propoxylated Derivatives, tricyclodecanedi(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, pentaerythritol di(meth)acrylate and tri(meth)acrylate and tetra(meth)acrylate and ethoxy thereof Sylated and/or propoxylated derivatives, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, propylene glycol Di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, neopentylglycol di(meth)acrylate, ethoxylated and/or propoxylated neopentylglycol di( Meth)acrylate, hexamethylene glycol di(meth)acrylate, 4,4'-bis(2-acryloyloxyethoxy ) Diphenylpropane, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate and its ethoxylated and/or propoxylated derivatives, dipentaerythritol tetra(meth)acrylate and penta(meth) ) Acrylate and hexa (meth) acrylate and ethoxylated and/or propoxylated derivatives thereof, and the like may be used.

In addition, the urethane (meth)acrylate generally has 2 to 15 (meth)acrylate functional groups. Urethane (meth)acrylates are generally capable of reacting with one or more polyisocyanates, one or more (meth)acrylate functional groups containing one or more (usually one) reactive groups capable of reacting with isocyanate groups and, optionally, isocyanate groups. Is obtained from the reaction of one or more compounds containing two or more reactive groups. The reactive group capable of reacting with an isocyanate group is generally a hydroxyl group. Examples include Miramer®PU240, Miramer®PU256, Miramer®PU2100, Miramer®UA5095, Miramer®PU3200, Miramer®PU3210, Miramer®PU330, Miramer®PU340, Miramer®PU370, Miramer®PU3410, Miramer®PU664, Miramer®SC2100 , Miramer®SC2153, Miramer®SC2152 (above Miwon Speciality Chemical), EBECRYL®4883, EBECRYL®9384, EBECRYL®1290, EBECRYL 220® (Alex), UV-3510TL, UV3000B, UV3310B, UV-7510B, Products such as UV-7600B and UV-1700B (above Nippon Gosei) can be purchased and used selectively.

In addition, the polyester (meth)acrylate can generally be obtained from an ester reaction with one or more polyols and one or more (meth)acrylic acid. It is preferable that acrylic acid and methacrylic acid are used alone or in combination. Suitable polyester (meth)acrylates include, for example, aliphatic or aromatic polyhydric polyols that are all esterified with (meth)acrylic acid and may contain residual hydroxyl functionality in the molecule, and characterize the product. An easy and suitable way for this is to measure its hydroxyl number (mgKOH/g). Suitable are partially or wholly esterified products of (meth)acrylic acid and di-hexavalent polyols and mixtures thereof. In addition, a reaction product of the polyol and ethylene oxide and/or propylene oxide or a mixture thereof, or a reaction product of the polyol and lactone and lactide as described above may be used. Examples include Miramer®PS420, Miramer®PS430, Miramer®PS460, Miramer®PS610 (above Miwon Specialty Chemical), EBECRYL®870, EBECRYL®657, EBECRYL®450, EBECRYL® 800, EBECRYL®884, EBECRYL®885 , EBECRYL®810, EBECRYL® 830 (above Alex), etc. can be purchased and used selectively.

In addition, the epoxy (meth)acrylate is generally obtained from the reaction of at least one polyepoxy compound and at least one (meth)acrylic acid. It is preferable that acrylic acid and methacrylic acid are used alone or in combination. Examples of suitable epoxy (meth)acrylate oligomers are di(meth)acrylates of the diglycidyl ether of bisphenol A and variants thereof, for example EBECRYL® 3700 or EBECRYL® 600, EBECRYL® 3701, EBECRYL® 3703 , EBECRYL® 3708, EBECRYL® 3720 and EBECRYL® 3639 (above Alex), Miramer® PE210, Miramer® PE2120A, Miramer® PE250 (above Miwon Specialty Chemical), and the like.

The photoinitiator may include at least one type of acylphosphine oxide type photoinitiator and at least one type of photoinitiator other than the acylphosphine oxide type. The acylphosphine oxide-based photoinitiator is bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-tribenzoyldiphenylphosphine oxide, ethyl-2,4,6 -It may be selected from the group consisting of triethylbenzoylphenylphosphinate and the like. In addition, photoinitiators other than the acylphosphine oxide system include, for example, α-hydroxyalkylphenone system, α-aminoalkylphenone system, benzoin ether ( Benzoineether), α,α-dialkoxyacetophenone, phenylglyoxylate, and the like. The α-hydroxyalkylphenone system, α-aminoalkylphenone system, benzoineether system, α,α-dialkoxyacetophenone (α,α-Dialkoxyacetophenone) As a system photoinitiator, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-hydroxy-1-[4-(2-hydroxyethoxy), α,α-dimethoxy-α-phenylacetophenone, 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone, methylbenzoyl formate, oxy -Phenyl-acetic acid 2-[2 oxo-2 phenyl-acetoxy-ethoxy]-ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester mixture selected from the group consisting of One or more can be mentioned.

The polythiol-based compound is a compound having two or more thiol functional groups, and one having one ester functional group per thiol functional group may be preferably used. The compounds having one ester functional group per thiol functional group include, for example, ethylene glycol dimercaptoacetate, trimethylolpropane trimercaptoacetate, pentaerythritol tetramercaptoacetate, dipentaerythritol hexamercaptoacetate, ethylene glycol Di(3-mercaptopropionate), trimethylolpropane tri(3-mercaptopropionate), dipentaerythritol hexa(3-mercaptopropionate), ethoxylated trimethylolpropane tri(3) -Mercaptopropionate), tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate, polycaprolactone tetra(3-mercaptopropionate), pentaerythritol tetrakis(3- Mertaptobutylate), 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2, At least one selected from the group consisting of 4,6(1H,3H,5H)-trione, and trimethylol propane tris (3-mercaptobutyrate), and the like may be used.

(2-5) spawning agent

The scattering agent is included in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the quantum dot layer to increase the optical path by scattering light entering the quantum dot layer, thereby increasing the chance of the light coming into contact with the quantum dot particles, thereby improving the light conversion rate. It plays a role to let. When the amount of the scattering agent is less than the above range, the scattering is lowered and thus the light conversion rate is insufficient. When the amount of the scattering agent is exceeded, the haze increases and the transmittance is lowered, so that sufficient luminance cannot be secured.

The scattering particles (E) are silica (Silica), alumina (Alumina), silicon (Silicon), alumina (Alumina), titanium dioxide (TiO ₂ ), zirconia (ZrO ₂ ), barium sulfate (Barium Sulfate), zinc oxide ( ZnO), poly(methylmethacrylate), PMMA), and may be one or more selected from the group consisting of benzoguanamine-based polymers. In addition, those having an average particle diameter of 0.01 to 10 nanometers may be preferably used.

In the present invention,% means'% by weight' unless otherwise specified. In addition, when the unit of concentration such as ppm is not specifically determined, it means'w/w' concentration.

Hereinafter, the present invention will be described in detail through examples. However, these examples are presented only to more clearly describe the present invention, and are not presented for the purpose of limiting the scope of the present invention. The scope of the present invention will be determined by the technical idea of the claims to be described later.

Synthesis Example 1: Synthesis of cadmium-containing green light emitting quantum dot particles (Cd-G1)

4 mmol of zinc acetate, 1 mmol of cadmium oxide and 10 ml of oleic acid, 15 ml of 1-octadecene (1-ODE), which had been dehydrated under reduced pressure at 120° C. for 30 minutes as a solvent, were added to the reactor, and argon Reacting for 2 hours at 160°C in an atmosphere, and removing acetic acid, a by-product generated during the reaction under reduced pressure conditions of 10 ^-2 torr, containing cadmium oleate (Cd-OA) and zinc oleate (Zn-OA) The first solution was prepared.

Separately, 0.5 mmol of selenium, 4 mmol of sulfur, and 2 mmol of trioctylphosphine were added to a reactor and reacted at 100° C. for 1 hour, and trioctylphosphine selenide (Se-TOP) and trioctylphosphine After preparing a second solution containing octylphosphine sulfide (S-TOP), the second solution was added to the prepared first solution, and a mixture of the first solution and the second solution was prepared. The temperature was raised to 300° C. and reacted for 2 hours. After that, after cooling to room temperature and precipitating with acetone, it was centrifuged using a complex solvent containing hexane and ethanol, and IBXA (Isobornyl Acrylate, Osaka Organic Chemical Co., Ltd.) to a concentration of 10% using UV-VIS equipment. ) To obtain an alloy-type quantum dot particle dispersion composed of selenium-sulfur-zinc-cadmium.

At this time, the content of Cd measured by ICP-MS in the 10% concentration of the quantum dot particle dispersion of Synthesis Example 1 was 7,495 ppm (7.5% by weight of cadmium content of only particles by conversion calculation), and Quantaurus-QY ( The maximum absorption wavelength measured by C11347-11) was 531.5 nm, the half width (FWHM) was 25 nm, and the Quantum Yield (%, internal) measured by Oscar Electronics' QE-2000 was 90.5%.

Synthesis Example 2: Synthesis of green light-emitting quantum dot particles (Cd-G2) containing cadmium

It was prepared in the same manner as in Synthesis Example 1, except that 2 mmol of zinc acetate and 3 mmol of cadmium oxide were used.

At this time, the content of Cd measured by ICP-MS in the 10% concentration of the quantum dot particle dispersion of Synthesis Example 2 was 22,761 ppm (22.8% by weight of cadmium content of particles alone by conversion calculation), and Quantaurus-QY ( The maximum absorption wavelength measured by C11347-11) was 530.5 nm, the half width (FWHM) was 23 nm, and the quantum yield (%, internal) measured by Oscar Electronics' QE-2000 was 93.9%.

Synthesis Example 3: Synthesis of cadmium-containing green light emitting quantum dot particles (Cd-G3)

It was prepared in the same manner as in Synthesis Example 1 except that 1 mmol of zinc acetate and 4 mmol of cadmium oxide were used.

At this time, the content of Cd measured by ICP-MS in the 10% concentration of the quantum dot particle dispersion of Synthesis Example 3 was 31,645 ppm (31.6% by weight of cadmium content of the particle alone by conversion calculation), and Quantaurus-QY ( The maximum absorption wavelength measured by C11347-11) was 530.0 nm, the half width (FWHM) was 21 nm, and the Quantum Yield (%, internal) measured by Oscar Electronics' QE-2000 was 96.8%.

Commercial product 1: Green luminescent quantum dot particles containing cadmium (Cd-G4)

Commercially available cadmium-type green luminescent particles (brand name: SQD-CG100H02, manufacturer: Uniam, IBXA 10% dispersion) were obtained and used. The content of Cd measured by ICP-MS of the 10% concentration of the quantum dot particle dispersion was 49,684 ppm (49.6% by weight of cadmium content of the particle alone by conversion calculation), measured by Hamamatsu's Quantaurus-QY (C11347-11) The maximum absorption wavelength was 522.8nm, the half width (FWHM) was 20nm, and the Quantum Yield (%, internal) measured by Oscar Electronics' QE-2000 was 97.6%.

Commercial product 2: Red light emitting quantum dot particles containing cadmium (Cd-R1)

Commercially available cadmium-type red luminescent particles (brand name: SQD-CR100H01, manufacturer: Uniam, IBXA 10% dispersion) were obtained and used. The content of Cd measured by ICP-MS of the 10% concentration of the quantum dot particle dispersion was 67,982 ppm (67.9% by weight of cadmium content of the particle alone as a conversion calculation), measured by Hamamatsu's Quantaurus-QY (C11347-11) The maximum absorption wavelength was 620.0nm, the half width (FWHM) was 21nm, and the Quantum Yield (%, internal) measured by Oscar Electronics' QE-2000 was 97.1%.

Commercial product 3: non-cadmium green light emitting quantum dot particles (InP-G1)

Commercially available non-cadmium type green light emitting particles (trade name: SQD-FG100H03, manufacturer Uniam, IBXA 10% dispersion) were obtained and used. The content of Cd measured by ICP-MS of the 10% concentration of the quantum dot particle dispersion was ND (Not Detect), and the maximum absorption wavelength measured by Hamamatsu's Quantaurus-QY (C11347-11) was 534.0 nm, half width ( FWHM) was 39 nm, and the Quantum Yield (%, internal) measured by Oscar Electronics' QE-2000 was 76.5%.

Commercial product 4: non-cadmium red light emitting quantum dot particles (InP-R1)

Commercially available non-cadmium type red luminescent particles (brand name: SQD-FR100H07, manufacturer Uniam, IBXA 10% dispersion) were obtained and used. The content of Cd measured by ICP-MS of the 10% concentration of the quantum dot particle dispersion was ND (Not Detect), and the maximum absorption wavelength measured by Hamamatsu's Quantaurus-QY (C11347-11) was 620.0 nm, half width ( FWHM) was 40 nm, and the Quantum Yield (%, internal) measured by Oscar Electronics' QE-2000 was 75.5%.

Cd-G1 Cd-G2 Cd-G3 Cd-G4 Cd-R1 InP-G1 InP-R1 Manufacturing method Synthesis Example 1 Synthesis Example 2 Synthesis Example 3 Commercial product 1 Commercial product 2 Commercial product 3 Commercial product 4 Cd content (%) 7.5 22.8 31.6 49.6 67.9 0.0 0.0 Maximum absorption wavelength (nm) 531.5 530.5 530.0 522.8 620.2 534.1 623.9 Half width (nm) 25 23 21 20 21 39 40 Quantum yield (%) 90.5 93.9 96.8 97.6 97.1 76.5 75.5

Preparation Example 1: Preparation of a composition for forming a quantum dot layer

M300 (Miwon Specialty Chemical, trimethylpropane triacrylate) 30 parts by weight, IBXA (Osaka Yuki, Isoborneol acrylate) 20 parts by weight, PEMP (SC Organic Chemical, Pentaerythritol Tetrakis (3-mercapto) Propionate)) 30 parts by weight, zinc oxide (Sakai Chemical Company FINEX 30, average particle diameter 35 nm) 6 parts by weight, 1-hydroxy-cyclohexyl-phenyl-ketone (IGM Corporation Igacure 184) 2 parts by weight, 2,4 ,6-tribenzoyldiphenylphosphine oxide (IGM's Darocure TPO) 2 parts by weight, Synthesis Examples 1 to 3, commercial products 1, and commercial products 2 8 parts by weight of each green light emitting quantum dot particle dispersion, commercial product 2 and commercial product 5 2 parts by weight of each red light emitting quantum dot particle dispersion is administered in a combination according to Table 2 below, and after high-speed stirring at a stirring speed of 500 rpm in a dispersion equipment equipped with an ITT (Intensive Type with Teeth) Dispersion Blade, pressurized with a 1um Teflon filter. Filtering and reducing pressure for 30 minutes to completely remove air bubbles in the resin to prepare a composition for forming a quantum dot layer.

Preparation Example 2: Preparation of a light conversion film including a quantum dot layer

The first transparent support layer is coated with the composition for forming each quantum dot layer prepared in Preparation Example 1 using a micro bar, and the second transparent support layer is laminated on the second transparent support layer using a rubber roll so that bubbles do not occur, and UV curing is performed. I did. At this time, the ultraviolet curing device was a Litgen's UV curing machine (UVMH1001) equipped with a metal halide lamp, and the amount of light in the UVA region measured using the EIT's UV Puck II was 1500 mJ. At this time, the thickness of the green light-emitting quantum dot particles, the red light-emitting quantum dot particles, the first transparent support layer, the second transparent support layer, and the quantum dot layer are shown in Examples and Comparative Examples in Table 2 below.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 1st transparent mechanism
(Material/Thickness μm) PET/
100 PET/
100 PET/
100 PET/
80 PET/
50 PET/
125 PET/
100 PET/
100 PET/
50 2nd transparent base (material/thickness μm) PET/
100 PET/
100 PET/
100 PET/
80 PET/
50 PET/
125 PET/
100 PET/
100 PET/
50 Green light-emitting particles Cd-G1 Cd-G2 Cd-G3 Cd-G3 Cd-G3 Cd-G3 InP-G1 Cd-G4 Cd-G3 Red light-emitting particles InP-R1 InP-R1 InP-R1 InP-R1 InP-R1 InP-R1 InP-R1 Cd-R1 InP-R1 Cadmium content of quantum dot composition
(ppm) 592 1822 2533 2533 2533 2533 0 5335 2533 Quantum dot layer thickness (μm) 80 80 80 40 80 100 80 100 125

Experimental Example: Evaluation of the characteristics of a light conversion sheet

(1) Optical characteristics

After cutting the quantum dot film to fit A4 size, attach it to the center of the backlight of the Samsung Electronics SUHD TV JS6500 model, apply power, and measure the luminance and color gamut of 13 points using a luminance meter (CS-2000, Minolta). The average value is shown in Table 3 below.

(2) cadmium content

After cutting the quantum dot film into 10 x 10 cm, the cadmium content was measured using ICP-MS, and the cadmium content was shown in Table 3 by 100 times the measured cadmium content.

Example
One Example
2 Example
3 Example
4 Example
5 Example
6 Comparative example
One Comparative example
2 Comparative example
3 Luminance (cd/m ² ) 761 796 776 771 821 768 650 899 862 Color reproduction rate (%) 117.5 125.3 137.4 120.6 137.4 129.4 107.4 147.2 140.1 (ppm) 12 42 57 20 98 74 N.D 154 176

1: liquid crystal display 10: liquid crystal
11: lower polarizing film 12: upper polarizing film
13: lower panel 14: upper panel
20: reflector 21: light-emitting element
22: light guide plate 23: light conversion film
24: luminance enhancing film 25: reflective polarizing plate
30: first transparent support layer 31: second transparent support layer
40: matrix material 41: quantum dot particles containing cadmium
42: quantum dot particles not containing cadmium 43: scattering agent
100: liquid crystal display panel, 200: backlight unit

Claims (15)

(a) 0.4 to 2% by weight of cadmium-containing quantum dot particles having a cadmium (Cd) content of 5 to less than 35% by weight;
(b) 0.05 to 0.75% by weight of quantum dot particles not containing cadmium;
(c) 75 to 98% by weight of the matrix material; And
(d) 0.1 to 10% by weight of a scattering agent; and,
The cadmium-containing quantum dot particles having a cadmium (Cd) content of 5 to less than 35 wt% have a maximum absorption wavelength of 525 to 540 nm,
The quantum dot particle not containing cadmium is a composition for forming a quantum dot layer, characterized in that the maximum absorption wavelength is 625 to 640nm. The method of claim 1,
The cadmium-containing quantum dot particles having a cadmium content of 5 to less than 35% by weight have a half width of 20 to 30 nm,
The composition for forming a quantum dot layer, characterized in that the quantum dot particle does not contain cadmium has a half width of 35 to 50nm. The method of claim 2,
The cadmium-containing quantum dot particles having a cadmium content of 5 to less than 35% by weight have an average particle diameter of 2.0 to 4.0 nm,
The composition for forming a quantum dot layer, characterized in that the quantum dot particles not containing cadmium have an average particle diameter of 5.0 to 7.0 nm. The method of claim 1,
The cadmium-containing quantum dot particles having a cadmium content of 5 or more to less than 35 wt% contain 0.1 to 4.5 mol of at least one selected from group II elements and III elements other than cadmium, based on 1 mol of cadmium, and a group V element And 0.5 to 6.0 moles of at least one selected from Group VI elements. The method of claim 4,
At least one selected from group II elements and III group elements other than cadmium is selected from the group consisting of zinc (Zn), mercury (Hg), indium (In), magnesium (Mg) and aluminum (Al),
At least one selected from the group V and VI elements is selected from the group consisting of phosphorus (P), arsenic (As), quality (N), sulfur (S), selenium (Se), and tellurium (Te). Composition for forming a quantum dot layer, characterized in that the. The method of claim 5,
The composition for forming a quantum dot layer, characterized in that at least one selected from among the group II and III elements other than cadmium is zinc (Zn). The method of claim 5,
At least one selected from the group V element and the group VI element is a composition for forming a quantum dot layer, characterized in that selected from sulfur (S) and selenium (Se). The method of claim 1,
The quantum dot particles that do not contain cadmium are at least one selected from Group V elements and VI elements based on 1 mole of at least one selected from Group II and III elements excluding cadmium (Cd) 0.2 to 4.0 A composition for forming a quantum dot layer, comprising a mole. The method of claim 8,
At least one selected from among Group II elements and Group III elements excluding cadmium (Cd) is selected from zinc (Zn) and indium (In), and at least one selected from the Group V and VI elements is sulfur (S), selenium (Se), tellurium (Te), and a composition for forming a quantum dot layer, characterized in that selected from phosphorus (P). The method of claim 9,
At least one selected from the group II and III elements excluding cadmium (Cd) is indium (In), and at least one selected from the group V and VI elements is phosphorus (P). A composition for forming a quantum dot layer. The method of claim 1,
The matrix material is a composition for forming a quantum dot layer, characterized in that it contains at least one (meth) acrylate-based compound, a polythiol-based compound, and at least one photoinitiator. The method of claim 11,
The matrix material comprises the (meth)acrylate-based compound, the polythiol-based compound, and the one or more photoinitiators in a weight ratio of 30 to 70:10 to 50:1 to 6 . The method of claim 1,
The composition for forming a quantum dot layer is a composition for forming a quantum dot layer, characterized in that the content of cadmium is 400 to 3000 ppm. The method of claim 11,
The (meth)acrylate-based compound is isobornyl (meth)acrylate, ethylhexyl (meth)acrylate, lauryl (meth)acrylate, octyldecyl (meth)acrylate, isooctyl (meth)acrylate, trimethyl Cyclohexyl (meth) acrylate, isodecyl (meth) acrylate, stearic (meth) acrylate, and tricyclodecane dimethanol di (meth) acrylate, characterized in that at least one selected from the group consisting of acrylate A composition for forming a quantum dot layer. The method of claim 1,
The (a) quantum dot particles containing a cadmium (Cd) content of 5 to less than 35% by weight are green light emitting particles, a maximum absorption wavelength of 525 to 540 nm, a half width of 20 to 30 nm, and a quantum yield of 90% to 99%, wherein (b) the quantum dot particles not containing cadmium are red light emitting particles, the maximum absorption wavelength is 625 to 640 nm, the half width is 35 to 50 nm, and the quantum yield is 70% to 85%. A composition for forming a quantum dot layer.

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