WO2020209579A1 - Iii-v-based quantum dots and method for manufacturing same - Google Patents

Abstract

Technology disclosed in the present invention provides a groups-III-V-based quantum dots and a method for manufacturing same, the quantum dots having a band gap control layer comprising: a seed comprising a group III element and a group V element; and a growth layer formed on the outer surface of the seed and comprising a group III element and a group V element. The quantum dots comprise an active metal which can have various oxidation numbers in at least one of the seed or growth layer forming the band gap control layer.

Description

Ⅲ-V system quantum dot and its manufacturing method

The present invention relates to a III-V quantum dot and a method of manufacturing the same.

Quantum dots (QD) are semiconducting nano-sized particles having a three-dimensionally limited size, and exhibit excellent optical and electrical properties that semiconducting materials do not have in a bulk state. For example, even if a quantum dot is made of the same material, the color of light emitted may vary depending on the size of the particle. Due to such characteristics, quantum dots are attracting attention as next-generation high-brightness light emitting diodes (LEDs), bio sensors, lasers, and nanomaterials for solar cells.

In addition, quantum dots have various advantages compared to fluorescent dyes of organic materials that are generally used. Through the quantum limiting effect by adjusting the size, it is possible to emit various spectra from quantum dots of the same composition, and it is possible to secure an emission spectrum with very high quantum efficiency and color purity of ~80% compared to dyes of organic materials. . In addition, since the quantum dot is a semiconductor composition of an inorganic material, it can have excellent light stability of about 100 to 1000 times compared to a fluorescent dye of an organic material.

Quantum dots using Ⅱ-VI compound semiconductor composition composed of Ⅱ and Ⅵ elements on the periodic table are materials capable of high luminous efficiency, light stability, and light in the visible region. come.

Research on representative II-VI compound semiconductor quantum dots has attracted a lot of attention due to its advantages such as high luminous efficiency and stability, but it contains Cd2+ and Se2-, which causes serious problems in terms of environmental hazards and toxicity. In addition, since application to the bio field may have a harmful effect on the human body, a lot of researches have recently been conducted on Ⅲ-V-based compound semiconductor quantum dots that can replace Ⅱ-VI quantum dots.

However, conventional group III-V semiconductor nanocrystals are sensitive to oxygen and moisture from precursors to obtained nanocrystals, and the synthesis process is not simple.

In addition, since it is not easy to control the growth rate of nanocrystals, the emission wavelength range is limited, and the color purity is low due to various size distributions, so the application to the light emitting device is limited. Therefore, there is a need for development of a new material capable of lowering the sensitivity to oxygen and moisture. In addition, there is an urgent need to develop a technology capable of controlling the growth rate of nanocrystals and growing them in a uniform size.

Prior art literature

(Patent Document 1) Korean Patent Registration No. 10-1462658 (Registration Date 2014.11.11)

(Patent Document 2) Republic of Korea Patent Publication No. 10-2018-0095955 (published on August 28, 2018)

An aspect of the present invention is to provide an active nanocluster used in the synthesis of III-V-based quantum dots capable of improving the half-width (FWHM) and obtaining high quantum efficiency.

Another aspect of the present invention is to provide a method for preparing the above-described active nanoclusters.

Another aspect of the present invention is to provide a III-V quantum dot having an improved half-width (FWHM) and high quantum efficiency using active nanoclusters.

Another aspect of the present invention is to provide a III-V quantum dot capable of improving the half-width (FWHM) and obtaining high quantum efficiency.

Another aspect of the present invention is to provide a method of manufacturing the aforementioned group III-V quantum dots.

According to an aspect of the present invention, an active metal oxide-carboxylate-containing active nanocluster is provided.

According to another aspect of the present invention, it provides a quantum dot comprising the above-described active nanoclusters.

According to another aspect of the present invention, a seed comprising a Group III element, a Group V element, and an active metal capable of having various oxidation numbers, and wherein the molar ratio of the Group III element and the active metal is 1:3 to 1:30 Branches provide group III-V quantum dots.

According to another aspect of the present invention, an active metal oxide obtained by thermally decomposing an active metal-carboxylate-a precursor step of forming an active nanocluster comprising a carboxylate; And a seed forming step of forming a seed in which an active metal, a group III element, and a group V element are alloyed by injecting a group III element precursor and a group V element precursor solution into the precursor solution prepared in the precursor step. It provides a method of manufacturing foot-based quantum dots.

According to another aspect of the present invention, a seed comprising a group III element and a group V element; And a growth layer including a group III element and a group V element formed on an outer surface of the seed. A group III-V quantum dot including an active metal capable of having various oxidation numbers in at least one of the seed or growth layer constituting the band gap control layer, having a band gap control layer comprising:

According to another aspect of the present invention, a group III element, a group V element, and an active metal capable of having various oxidation numbers are included, and selected from the group consisting of Al, Ga, Ti, Mg, Na, Li, and Cu. The quantum dot has a seed doped with at least one additional element, and the quantum dot provides a III-V group quantum dot having an emission wavelength of 500 nm to 650 nm and a half width of 50 nm or less.

According to another aspect of the present invention, a group III element, a group V element, and an active metal capable of having various oxidation numbers are included, and selected from the group consisting of Al, Ga, Ti, Mg, Na, Li, and Cu. As a group III-V quantum dot having a seed containing at least one additional element, the raw material of the active metal provides a group III-V quantum dot, which is an active nanocluster solution containing a compound represented by the following formula (1).

[Formula 1] T _x O _y (Carboxylate) _z

In Formula 1, T is selected from the group consisting of Zn, Mn, Cu, Fe, Ni, Co, Cr, Ti, Zr, Nb, Mo, Ru, and combinations thereof, and x, y, z are natural numbers, x>y.

According to another aspect of the present invention, an active metal oxide obtained by thermally decomposing an active metal-carboxylate-a precursor step of forming an active nanocluster comprising a carboxylate; And a solution containing a group III element precursor, a group V element precursor, and at least one additional element selected from the group consisting of Al, Ga, Ti, Mg, Na, Li, and Cu to the precursor solution prepared in the precursor step. It provides a method of manufacturing a group III-V quantum dot comprising a seed forming step of alloying an active metal with a group III element and a group V element, and forming a seed containing the additional element.

The active nanocluster according to an aspect of the present invention has an effect of efficiently forming quantum dots and suppressing rapid saturation of the growth of quantum dots, thereby improving half-width and increasing quantum efficiency.

The active nanocluster according to another aspect of the present invention can be effectively prepared by heating an active metal-carboxylate and thermally decomposing it for a predetermined time.

In addition, the III-V-based quantum dots according to another aspect of the present invention suppress rapid precursor depletion, thereby improving the half-width (FWHM) and having high quantum efficiency.

In addition, the method of manufacturing a III-V quantum dot according to another aspect of the present invention has an advantage that it is more suitable for mass production than a conventional method for synthesizing high-efficiency quantum dots by synthesizing a highly reactive reaction medium through simple pyrolysis.

In addition, in the group III-V quantum dots according to another aspect of the present invention, a solution containing one or more additional elements selected from the group consisting of Al, Ga, Ti, Mg, Na, Li, Sn, and Cu is injected to prevent lattice mismatch. There is an effect of improving the half-width (FWHM) and increasing the quantum efficiency by reducing and controlling surface defects inside the seed.

1 is a schematic diagram showing a method of manufacturing an active nanocluster according to an aspect of the present invention.

2 is a graph showing MALDI-TOP (Matris Assisted Laser Desorption-Time of Flight) data obtained from the solution prepared in Example 1 in order to identify the active nanoclusters according to an aspect of the present invention.

3 is a graph measuring UV and PL spectra of the seed of the quantum dots of Example 4 of the present invention and the seed of the quantum dots of Comparative Example 2.

Figure 4 is a graph of measuring UV and PL spectrum by preparing the quantum dot of Example 4 and the quantum dot of Comparative Example 2 of the present invention.

5 is a graph of measuring a PL spectrum by preparing the quantum dots of Example 5 and Comparative Example 3 of the present invention.

6 is a graph measuring a PL spectrum for each step of seed, growth, and shell formation in the quantum dot of Example 5 of the present invention.

Hereinafter, a method of manufacturing an active nanocluster and a quantum dot according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

In order to clearly describe the present invention, portions irrelevant to the description have been omitted, and the sizes and thicknesses of each component shown in the drawings are arbitrarily shown for convenience of description, so the present invention is not necessarily limited to what is shown. In the drawings, the thicknesses are enlarged to clearly express various layers and regions. And in the drawings, for convenience of description, the thickness of some layers and regions is exaggerated.

In addition, when a part such as a layer, film, region, plate, etc. is said to be "on" or "on" another part, this includes not only "directly over" another part, but also a case where another part is in the middle. . Conversely, when one part is "right above" another part, it means that there is no other part in the middle. In addition, to say "on" or "on" the reference part means that it is located above or below the reference part, and means that it is located "above" or "on" in the direction opposite to gravity. no.

In addition, throughout the specification, when a certain part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated.

In addition, throughout the specification, the term "on a plane" means when the target part is viewed from above, and when "on a cross-sectional view", it means when the target part is viewed from the side.

In the present invention, "active metal precursor" refers to a chemical substance prepared in advance to react an active metal, and refers to all compounds including an active metal.

<The first aspect of the present invention>

The first aspect of the present invention is an active nanocluster including an active metal oxide-carboxylate. In the present invention, the active metal refers to a metal that can be used as a metal in a metal oxide-carboxylate having an activity that is included in a seed, an active layer, a shell, etc. during the manufacture of a quantum dot to improve the half width and contribute to the improvement of quantum efficiency.

As the active metal, at least one selected from the group consisting of Zn, Mn, Cu, Fe, Ni, Co, Cr, Ti, Zr, Nb, Mo, Ru, and combinations thereof that may have various oxidation numbers may be used.

In addition, the active metal oxide is an oxide of an active metal selected from the group consisting of Zn, Mn, Cu, Fe, Ni, Co, Cr, Ti, Zr, Nb, Mo, Ru, and combinations thereof, and is active in the present invention. The nanocluster may include the active metal oxide alone or in combination of two or more.

In the present invention, "cluster" refers to a particle in which a single atom, molecule, or other type of atom is agglomerated or bound within hundreds to thousands of atoms. The particle average particle diameter of such a cluster is preferably 1.5 nm or less, for example, and the lower limit of the average particle diameter is 0.5 nm, which is more preferable because it can suppress rapid saturation of the growth of quantum dots.

The active nanocluster includes an active metal oxide-carboxylate. In this case, the active metal oxide-carboxylate includes a compound represented by the following formula (1).

[Formula 1] T _x O _y (Carboxylate) _z

In the above formula, T is an active metal, and carboxylate is a salt or ester of a carboxylic acid, the salt of a carboxylic acid has the general formula M(RCOO)n, and the carboxylate ester is a general formula of RCOOR'. With the formula, M is a metal, n is a natural number, and R and R'are organic groups other than hydrogen.

At this time, x, y, z are natural numbers, x>y, and x+y=z or 2x=2y+z.

In addition, the active metal oxide-carboxylate may include two or more active metal oxides having different values of x.

For example, the value of x of the two or more different active metal oxides may be 2 to 10.

Two or more active metal oxides having different x values may each satisfy a relationship of x+y=z. For example, it may include Zn ₄ O (carboxylate) ₅ , Zn ₇ O ₂ (carboxylate) ₉ , and the like.

Two or more active metal oxides having different x values may each satisfy a relationship of 2x=2y+z. For example, it may include Zn ₄ O (carboxylate) ₆ , Zn ₇ O ₂ (carboxylate) ₁₀ and the like.

The term "active nanocluster" used in the present invention refers to an active metal oxide-carboxylate.

For reference, the active metal oxide reacts with an active metal precursor and a carboxylic acid to synthesize an active metal-carboxylate, and thermally decomposes the active metal oxide to convert all of the active metal oxide particles through the form of an active metal oxide-carboxylate. Therefore, such an active metal oxide is usually used.

Meanwhile, in the present invention, a solution containing an active metal oxide-carboxylate (hereinafter, referred to as an active nanocluster solution) is formed through multi-stage control of the thermal decomposition temperature, and the active nanocluster solution is used as a raw material of the active metal oxide. It can provide one technical feature for what you use.

Unlike the prior art, by using the active nanocluster solution, a quantum dot having an alloy bond between a group III element and a group V element can be prepared, and as a result, the half width (FWHM) is improved and the quantum efficiency is increased, By suppressing the rapid saturation of the quantum dot growth, it is possible to provide an effect of efficiently growing the quantum dot.

In this case, the active nanocluster solution includes the active metal oxide-carboxylate and the active metal-carboxylate.

For example, when zinc is used as the active metal, Zn oleate is first synthesized by the reaction of oleic acid as a carboxylate with Zn acetate, which is an active metal precursor. When this is pyrolyzed by two-step temperature control, active nanoclusters such as Zn ₄ O (carboxylate) ₅ , Zn ₇ O ₂ (carboxylate) ₉ , Zn ₄ O (carboxylate) ₆ , and Zn ₇ O ₂ (carboxylate) ₁₀ are synthesized. And ZnO nanoparticles are obtained as a final reactant. Therefore, before all Zn oleate is converted into ZnO nanoparticles, active metal oxide-carboxylate as an active nanocluster exists in a solution in which unreacted Zn oleate (corresponding to the aforementioned active metal-carboxylate) is mixed. .

In fact, the content ratio of the active metal oxide-carboxylate and the active metal-carboxylate contained in the active nanocluster solution can be confirmed by measuring the weight change according to the activation of the active metal precursor. For example, referring to Figure 2, which shows the measurement results using MALDI-TOP (Matris Assisted Laser Desorption-Time of Flight), when activated, 1683 m/z as well as 975 m/z appearing in the existing black graph as well as the red graph , Peak at 3020 m/z, and as a result of calculating the abundance ratio by integrating each peak and comparing the areas, 1683 m/ which represents Zn ₄ O(carboxylate) ₆ and Zn ₇ O ₂ (carboxylate) ₁₀ , respectively, among all peaks. It was confirmed that the mass distribution occupied by the z and 3020m/z peaks was about 80%.

That is, in this aspect, the active metal oxide-carboxylate has a higher mass distribution than the active metal-carboxylate, and is preferably included in a ratio of 60:40 to 99:1.

That is, the active nanocluster improves the half-width (FWHM) and increases the quantum efficiency during quantum dot manufacturing. In addition, quantum dots grow efficiently by suppressing rapid saturation of the growth of quantum dots. That is, the half width of the quantum dot is, for example, 50 nm or less, preferably 30 nm to 45 nm, more preferably 34 nm to 45 nm.

<Second aspect of the present invention>

A second aspect of the present invention shows a method for producing an active nanocluster containing an active metal oxide-carboxylate obtained using an active metal-carboxylate.

In other words, the active nanocluster is prepared by reacting an active metal precursor with a carboxylic acid to prepare an active metal oxide-carboxylate and then thermally decomposing it. Specifically, the manufacturing method includes step 1-1, step 1-2, step 1-3, and step 1-4. The name of each step is a name given to distinguish each step from other steps, and does not include all the technical meanings of each step.

Step 1-1 is a step of reducing pressure by mixing an active metal precursor and a carboxylic acid.

Active metal precursors include, for example, dimethyl zinc, diethyl zinc, zinc acetate, zinc acetate dihydrate, and zinc acetylacetonate when the active metal is zinc. (Zinc acetylacetonate), Zinc acetylacetonate hydrate, Zinc iodide, Zinc bromide, Zinc chloride, Zinc fluoride, Zinc fluoride Zinc fluoride tetrahydrate, Zinc carbonate, Zinc cyanide, Zinc nitrate, Zinc nitrate hexahydrate, Zinc oxide, Zinc Zinc peroxide, Zinc perchlorate, Zinc perchlorate hexahydrate, Zinc sulfate, Diphenyl zinc, Zinc naphthenate, Zinc oleate (Zinc oleate) and zinc stearate (Zinc stearate) may be at least one selected from the group consisting of.

Accordingly, the same can be applied even when the active metal is not zinc.

Carboxylic acid is required to react with the active metal precursor to make an active metal-carboxylate, and palmitic acid, myristate acid, oleic acid, stearic acid, and the like may be used.

In the first step 1-1, the active metal precursor and the carboxylic acid are mixed in a molar ratio of 1:1 to 1:3 to prepare a mixed solution. If it is out of the above range, there is a problem in that unreacted excess salt or acid may unintentionally participate in the subsequent process.

At this time, the pressure to be reduced is preferably 100 torr to 0.001 torr, for example. If it is out of the above range, there occurs a problem that the removal of impurities or additionally generated products is not smooth.

Step 1-2 is a step of first reacting the mixed solution after raising the temperature of the mixed solution after step 1-1 to a first temperature. The range of the first temperature varies depending on the type of carboxylic acid to be used, but is preferably room temperature (25°C) to 200°C as an example. At this time, the pressure is maintained as it is. In this case, the heating time is, for example, 10 minutes to 1 hour, and the reaction time is preferably 10 minutes to 3 hours, for example.

Step 1-3 is a step in which the mixed solution after step 1-2 is heated to a second temperature higher than the first temperature, and then the mixed solution is subjected to a secondary reaction. The range of the second temperature may be in the range of 200°C to 500°C, for example, and is preferably a temperature higher than the first temperature. At this time, the pressure is maintained as it is. In this case, the heating time is, for example, 10 minutes to 1 hour, and the reaction time is preferably 10 minutes to 3 hours, for example.

Steps 1-4 are steps of injecting the mixed solution into the solvent in an inert atmosphere and then lowering the temperature to the third temperature (decreasing temperature). The solvent is for controlling the concentration of the mixed solution, and both a coordinating solvent and a non-coordinating solvent may be used, and in general, octadecene may be used. The range of the third temperature may be room temperature, and the pressure may maintain normal pressure. The temperature reduction time is preferably 20 minutes to 2 hours.

After steps 1-4, an active nanocluster solution containing [Formula 1] T _x O _y (Carboxylate) _z is prepared. 1 is a schematic diagram in which an active nanocluster of the present embodiment is generated. According to this, it can be seen that the active metal-stearate in the solid state obtained by reacting the active metal precursor with the carboxylic acid was dissolved at 140°C, and then activated at 320°C to form an active nanocluster.

In the present invention, quantum dots can be prepared using active nanoclusters. The quantum dot includes a seed and a shell, wherein the shell may be selectively included, and the seed is alloyed with an active metal derived from the above-described active nanocluster.

In another aspect, the present invention can prepare an active nanocluster using a method for producing an active nanocluster, through which quantum dots can be manufactured.

<The third aspect of the present invention>

A third aspect of the present invention is a group III-V quantum dot synthesized using the active nanocluster according to the first aspect.

The quantum dot on the third side includes a seed and a shell. In this case, the shell may be selectively included, and the active metal derived from the aforementioned active nanocluster is alloyed and included in the seed.

Here, the active metal may be at least one selected from the group consisting of Zn, Mn, Cu, Fe, Ni, Co, Cr, Ti, Zr, Nb, Mo, Ru, and combinations thereof, which may have various oxidation numbers. have.

In the present invention, the molar ratio of the group III element: active metal in the present invention may be, for example, 1:3 to 1:30, preferably 1:3 to 1:20, more preferably 1:4 It may be from 1:15, and more preferably from 1:5 to 1:10. When the concentration of the active metal exceeds the above range, there is a problem in that the growth of the quantum dots is limited. When the concentration of the active metal exceeds the above range, the growth of the quantum dots is rapidly saturated and the stability of the crystal lattice is deteriorated, thereby reducing the efficiency of the quantum dots.

The activated active metal precursor may be an active nanocluster including the active metal oxide-carboxylate of Formula 1 described in the first aspect of the present invention.

Seeds are Group III elements Al, Ga, In, Ti or a combination thereof and group V elements P, As, Sb, Bi, or a combination thereof, for example, GaN, GaP, GaAs, GaSb, AlN, AlP , AlAs, AlSb, InN, InP, InAs, InSb, and a binary compound selected from the group consisting of a mixture thereof; A three-element compound selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, InGaP, and mixtures thereof; And GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, GaAlNP, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and a quaternary compound selected from the group consisting of mixtures thereof. The active metal is alloyed.

When the active metal is alloyed with a group III element or a combination thereof, a group V element, or a combination thereof, the active metal appears to play a role in stabilizing the crystal lattice in the seed and complementing the defect. In this case, the active metal is an active metal derived from an active nanocluster.

In addition, the molar ratio of the group III element and the group V element of the seed may be, for example, 1: 0.5 to 1: 1.2, and preferably 1: 0.7 to 1: 1. When the molar ratio of the group III element and the group V element exceeds the above range, there is a problem that it is difficult to obtain a quantum dot in a desired wavelength band, and if it is less than the above range, there is a problem that even growth is suppressed.

Additionally, the seed may contain additional elements. Additional elements are included in the seed to change the properties of the quantum dot depending on the content. When additional elements such as Al, Ga, Ti, Mg, Na, Li, and Cu are included in the seed, there is an effect of increasing quantum efficiency by reducing surface defects by preventing lattice mismatch.

In this case, the molar ratio of the group III element of the seed: the additional element may be, for example, 1: 0.2 to 1: 0.8, and preferably 1: 0.3 to 1: 0.6. When the molar ratio of the group III element and the additional element of the seed exceeds or is less than the above range, the quantum efficiency may not be changed because the lattice mismatch cannot be effectively prevented.

The shell is formed by surrounding the outer surface of the seed. The shell may be one selected from the group consisting of a II-VI semiconductor, a III-V semiconductor, and a IV-VI semiconductor material. The shell can increase stability by coating the outer surface of the seed to prevent surface defects of the nanocrystals.

As the Group II element, one selected from the group consisting of Zn, Cd, Hg, Mg, or a combination thereof may be used, and as the Group III element, one selected from the group consisting of Al, Ga, In, Ti or a combination thereof , And as a Group IV element, one selected from the group consisting of Si, Ge, Sn, Pb, or a combination thereof may be used, and as a Group VI element, in the group consisting of O, S, Se, Te or a combination thereof Any one of your choice can be used.

In the present invention, the shell is preferably a group II-VI semiconductor. At this time, the molar ratio of the group III element of the seed and the group VI element of the precursor used to form the shell may be, for example, 1: 3 to 1: 20, preferably 1: 5 to 1: 15, and , More preferably, it may be 1: 8 to 1: 10. When the molar ratio of the precursor used for shell coating is greater than or less than the above ratio, there is a problem in that uniform shell coating is not achieved.

In this aspect, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, PbS, PbSe, PbSeS, PbTe, GaAs, GaP, InP, InGaP, InZnP, InAs, CuS, InN, GaN, InGaN, AlP, AlAs, InAs , GaAs, GaSb, InSb, AlSb, HgS, HgTe, HgCdTe, ZnCdS, ZnCdSe, CdSeTe, CuInSe2, CuInS2, AgInS2, SnTe, etc. can be used as shell materials.

In active metal alloy III-V quantum dots, the average diameter of the quantum dots is, for example, 1.5 nm to 5 nm, and the thickness of the shell alone is preferably 0.5 nm to 5 nm, or 0.5 nm to 1 nm, for example. If it is out of the above range, the emission wavelength does not match or the efficiency is deteriorated.

The quantum dot according to this aspect has a light emission wavelength of 500 nm to 650 nm, or 540 nm to 650 nm, for example, and a half width of 50 nm or less, 30 nm to 45 nm, or 34 to 45 nm, for example.

<Fourth aspect of the present invention>

The manufacturing method of group III-V quantum dots includes a precursor step, a seed formation step, a shell formation step, and a purification step. The name of each step is a name given to distinguish each step from other steps, and does not include all the technical meanings of each step.

The precursor step is a step of preparing an active nanocluster of Formula 1 defined in the second aspect of the present invention. Active nanoclusters are prepared by pyrolyzing an active metal-carboxylate. The precursor step is the same as step 1-1, step 1-2, step 1-3, and step 1-4 as described in the second aspect of the present invention, and detailed descriptions are omitted.

The seed formation step is a step of injecting a group III element precursor and a group V element precursor solution into the precursor solution prepared in the precursor step to form a seed in which an active metal, a group III element, and a group V element are alloyed. The seed formation step includes step 2-1, step 2-2, step 2-2, and step 2-4.

Step 2-1 is a step of mixing and stirring the active nanocluster solution, the group III element precursor solution, and the solvent. The active nanocluster solution is as described above.

The Group III element precursor solution contains a Group III element precursor, a solvent, and a surfactant. As the Group III element precursor, all precursors containing Group III elements, such as a halogen salt of a Group III element, may be used.

When the group III element is indium, the indium precursor may be, for example, indium acetylacetonate, indium chloride, indium acetate, and trimethyl indium. indium), Alkyl Indium, Aryl Indium, Indium(III) Myristate, Indium(III) Myristate Acetate and Indium Myristate 2 acetate (Indium(III) Myristate) ) Myristate 2 Acetate) may be any one selected from the group consisting of, preferably indium acetylacetonate (Indium(III) acetylacetonate).

The solvent is 2,6,10,15,19,23-hexamethyltetrachoic acid (Squalane), 1-octadecene (ODE), trioctylamine (TOA), tributylphosphine oxide, octadecene, octadecylamine, It may be at least one selected from the group consisting of trioctylphosphine (TOP) and trioctylphosphine oxide (TOPO).

The surfactant may be selectively used, and may be a carboxylic acid-based compound, a phosphonic acid-based compound, or a mixture of these two compounds.

Carboxylic acid-based compounds include, for example, oleic acid, palmitic acid, stearic acid, linoleic acid, myristic acid, and lauric acid. It may be one or more selected from the group consisting of, and the phosphonic acid-based compound is for example hexylphosphonic acid, octadecylphosphonic acid, tetradecylphosphonic acid, hexadecylphosphonic acid ( It may be at least one selected from the group consisting of hexadecylphosphonic acid), decylphosphonic acid, octylphosphonic acid, and butylphosphonic acid.

Step 2-2 is a step of reacting for 50 to 100 minutes after raising the temperature to A temperature for 5 to 20 minutes while decompressing the solution of step 2-1. A temperature is, for example, 100 ℃ to 150 ℃. At a temperature lower than the above range, there is a possibility that impurities in the precursor may not be removed, and when the temperature is higher than the temperature range, the concentration of the solution changes, which may hinder efficient quantum dot growth.

Step 2-3 is a step of raising the temperature of the solution of step 2-2 to the B temperature for several seconds to 1 hour in an inert atmosphere, and injecting the group V element precursor solution. The B temperature is higher than the A temperature and is preferably 200°C to 400°C. When the temperature is lower than the temperature range, quantum dot formation does not occur effectively, and when it is higher than the temperature, it is difficult to control the emission wavelength.

The Group V element precursor solution contains a Group V element precursor and a solvent. Group V element precursors are, for example, tris(trimethylsilyl)phosphine ((Tris(trimethylsilyl)phosphine, TMSP), aminophosphine, white phosphorus, tris(pyrazolyl)phosphane), Organometallic phosphorus such as calcium phosphide may be used.

At this time, an alkylphosphine-based surfactant can be added to the group V element precursor solution, and when added together, the group V element and the alkylphosphine-based surfactant are combined to form a new organic complex. Stable reaction is possible, making it more suitable for mass production. The size of the quantum dots may be adjusted according to the type of the alkylphosphine surfactant. The alkylphosphine-based surfactant is not limited thereto, but triethyl phosphine, tributyl phosphine, trioctyl phosphine, triphenyl phosphine, and triphenyl phosphine. It may be one or more selected from the group consisting of cyclohexyl phosphine.

The solvent of the group V element precursor solution may include, for example, trioctylphosphine (TOP), tributylphosphine (TBP), octadecene (ODE), amines (primary amine, secondary amine, third amine), etc., The molar concentration of the group V element precursor solution is preferably 0.001M to 2M, for example.

In this case, it is preferable that the molar ratio of the active metal and the group V element is, for example, 1: 0.02 to 1: 0.006, and 1: 0.03 to 1: 0.005. If it is out of the above range, a problem of forming non-uniform quantum dots may occur.

The shell formation step is a step of forming a shell on the seed surface after the seed formation step. The shell forming step includes steps 4-1, 4-2, and 4-3.

In step 4-1, the shell is formed by injecting one or both of a group III element precursor solution and a group V element precursor solution, or one or both of a group II element precursor solution and a group VI element precursor solution. That is, the shell is formed by injecting a group II element precursor or/and a group VI element precursor or a group III element precursor or/and a group V element precursor.

It is preferable that the shell is made of a II-VI group semiconductor.

In this case, the molar ratio of the group III element of the seed and the group VI element of the precursor used to form the shell may be, for example, 1: 3 to 1: 20, preferably 1: 5 to 1: 15, and , More preferably, it may be 1: 8 to 1: 10. When the molar ratio of the precursor used for shell coating is greater than or less than the above ratio, there is a problem in that uniform shell coating is not achieved.

On the other hand, when a shell is formed from a group II element and a group VI element, the group II element remains unreacted group II element involved in the formation of the active nanocluster, so that the group II element can be included without a separate injection.

Step 4-2 is a step of heating the solution in step 4-1 to X° C. for 10 to 30 minutes and reacting for 2 to 4 hours. The range of X temperature is preferably 200°C to 400°C. If it is out of the above temperature range, there is a problem that effective shell coating is not performed.

Step 4-3 is a step of cooling to room temperature while blowing the solution in step 4-1 with an inert gas. If the inert gas is not blown, there is a problem that the surface of the quantum dot is oxidized due to the injection of air at a high temperature.

The purification step includes step 5-1, step 5-2, and step 5-3.

In the 5-1 step, the solution after the shell formation step is placed in a container capable of centrifugation, and for example, an alcohol solvent and a polar solvent (eg, 2-propanol) are added and centrifuged to discard the supernatant to obtain a precipitate. Step.

In addition, the number of rotations during centrifugation is preferably 1000 rpm to 20000 rpm, for example.

Step 5-2 is a step of dissolving the precipitate in an organic solvent such as hexane, toluene, octadecane, and heptane.

Step 5-3 is a step of repeating steps 5-1 and 5-2 at least once, and then storing them in a dissolved state in a non-polar solvent.

<Fifth aspect of the present invention>

The fifth aspect of the present invention is a group III-V quantum dot synthesized using the active nanocluster according to the first aspect.

The fifth side of the quantum dot is a seed containing a group III element and a group V element; And a growth layer including a group III element and a group V element formed on the outer surface of the seed, and a variety of oxidation numbers are applied to at least one of the seed and the growth layer constituting the bandgap control layer. It is a group III-V quantum dot containing an active metal that may have.

The term “band gap control layer” used in the present invention refers to a layer that has a seed and a growth layer and provides improved half width and light emission efficiency by controlling the band gap.

The growth layer is a semiconductor layer grown on the outer surface of the seed, and the growth layer is a III-V semiconductor layer composed of a group III element or a combination thereof and a group V element or a combination thereof, and the group III elements and group V included in the seed It may be made of the same type of semiconductor material as the element, and may contain an active metal. In addition, at least one of the seed and the growth layer should be included in the active metal.

The activated active metal precursor may be an active nanocluster including the active metal oxide-carboxylate of Formula 1 described in the first aspect of the present invention.

The description of the seed overlapping with the seed disclosed in the third aspect of the present invention will be omitted. The seed may further include additional elements. Additional elements are included in the seed to change the properties of the quantum dot depending on the content. When additional elements such as Al, Ga, Ti, Mg, Na, Li, and Cu are included in the seed, there is an effect of increasing quantum efficiency by reducing surface defects by preventing lattice mismatch.

In this case, the molar ratio of the group III element of the seed: the additional element may be, for example, 1: 0.2 to 1: 0.8, and preferably 1: 0.3 to 1: 0.6. When the molar ratio of the group III element and the additional element of the seed exceeds or is less than the above range, it does not effectively prevent lattice mismatch, and thus there may be no change in quantum efficiency.

The growth layer is a semiconductor layer grown on the outer surface of the seed. The growth layer is a group III-V semiconductor layer composed of a group III element or a combination thereof and a group V element or a combination thereof, and the group III element and group V element included in the seed It may be made of the same type of semiconductor material and contains an active metal. The active metal at this time may also be made of the same type as the active metal included in the seed.

When the active metal is alloyed with a group III element or a combination thereof and a group V element or a combination thereof, the active metal serves to stabilize the crystal lattice in the seed and compensate for defects.

At this time, the molar ratio of the group III element of the bandgap control layer and the active metal of the bandgap control layer may be, for example, 1: 0.2 to 1: 2, preferably 1: 0.2 to 1: 1, more Preferably, it may be 1:0.5 to 1:1. When the concentration of the active metal exceeds the above range, growth of the growth layer is suppressed, and it is difficult to control the wavelength of the nanocrystal, and when the concentration is less than the above range, luminous efficiency may be lowered.

In addition, the molar ratio of the group III element of the band gap control layer and the group V element of the band gap control layer may be, for example, 1: 0.5 to 1: 2, preferably 1: 0.5 to 1: 1, More preferably, it may be 1:0.6 to 1:1. When the concentration of the group V element in the bandgap control layer exceeds the above range, the stability of the synthesized quantum dots may be lowered.

In this case, the thickness of the growth layer included in the bend gap control layer may be, for example, 0.5 nm to 2.5 nm, and preferably 1 nm to 2 nm. If it exceeds the above range, there is a problem of red shifting than the desired wavelength band, and if it is less than the above range, there is a problem that the stability of the quantum dot is deteriorated.

When an active metal is included in the growth layer included in the bandgap control layer, the molar ratio of the group III element and the active metal of the bandgap control layer may be, for example, 1:0.2 to 1:2, and preferably 1:0.2. It may be from 1: 1, more preferably from 1: 0.3 to 1: 0.8. When the concentration of the active metal exceeds the above range, growth of the growth layer is suppressed, and it is difficult to control the wavelength of the nanocrystal, and when the concentration is less than the above range, luminous efficiency may be lowered.

The growth layer included in the band gap control layer may further include an additional element. Additional elements are included in the growth layer to change the properties of the quantum dot depending on the content. When the growth layer contains additional elements other than the active metal, for example, Al, Ga, Ti, Mg, Na, Li, and Cu, the growth of the growth layer may be promoted and the emission wavelength may be changed.

Accordingly, in an embodiment, the molar ratio of each element in the seed may be, for example, In: Zn: P = 1: 8: 0.7, and the molar ratio of each element in the bandgap control layer is In: Zn: It may be P = 1: 0.7: 0.9.

The shell is formed by surrounding the outer surface of the seed and the growth layer, that is, the band gap control layer. The shell is as described in the second aspect of the present invention.

The quantum dot according to this aspect has a light emission wavelength of 500 nm to 650 nm, or 540 nm to 650 nm, for example, and a half width of 50 nm or less, 30 nm to 45 nm, or 34 nm to 45 nm, for example.

<The sixth aspect of the present invention>

The method of manufacturing an active metal alloy III-V quantum dot includes a precursor step, a seed formation step, a growth layer formation step, a shell formation step, and a refining step. Here, the step of forming the seed and the step of forming the growth layer may be referred to as a step of forming a band gap control layer. The name of each step is a name given to distinguish each step from other steps, and does not include all the technical meanings of each step. In particular, the precursor step is interpreted as a concept separate from the active metal precursor.

The precursor step may be a step of preparing an active nanocluster of Formula 1 defined in the second aspect of the present invention. The precursor step is the same as step 1-1, step 1-2, step 1-3, and step 1-4 as described in the second aspect of the present invention, and a detailed description thereof will be omitted.

The seed formation step is a step of injecting a group III element precursor and a group V element precursor solution into the precursor solution prepared in the precursor step to form a seed in which an active metal, a group III element, and a group V element are alloyed. The seed formation step may be the same as step 2-1, step 2-2, step 2-2, and step 2-4, and detailed descriptions will be omitted.

The growth layer formation step is a step of forming a growth layer on the outer surface of the seed after the seed formation step. The growth layer is a semiconductor layer grown on the outer surface of the seed. The growth layer is a group III-V semiconductor layer composed of a group III element or a combination thereof and a group V element or a combination thereof, and the group III and group V elements included in the seed It may be made of the same type of semiconductor material and contains an active metal. The active metal at this time may also be made of the same type as the active metal included in the seed.

The growth layer is formed by injecting a group III element-active metal-group V element (hereinafter referred to as 3-M-5) complex solution to the solution in the seed formation step.

In the 3-M-5 complex solution, the molar ratio of the group III element and the active metal is preferably 1: 0.2 to 1: 0.8, and the molar ratio of the active metal and the group V element is, for example, 1: 1 to 1: 1.5 It is preferable to be. In the case of a molar ratio outside the above range, there is a problem in that non-uniform quantum dots are synthesized because the growth of the growth layer does not occur evenly.

The 3-M-5 complex solution is injected into the solution at temperature B after the seed formation step, and reacted, and the temperature is reduced to temperature C in an inert atmosphere. The range of the C temperature is preferably 130°C to 170°C, for example. The reason for reducing the temperature to the C temperature is to inject the shell precursor, and when the temperature is higher than the above temperature range, uniform shell coating is not formed, and the half width is widened.

On the other hand, the 3-M-5 complex solution is a solution in which a group III element, an active metal, and a group V element are mixed, and the preparation method of the 3-M-5 complex solution includes steps 3-1, 3-2, and It includes steps 3-3, 3-4 and 3-5.

Step 3-1 is a step of injecting and stirring a group III element precursor, an active metal precursor, and a solvent.

As the Group III element precursor, any precursor containing a Group III element such as a halogen salt of a Group III element may be used. When the group III element is indium, the indium precursor is, for example, indium acetylacetonate, indium chloride, indium acetate, trimethyl indium indium), Alkyl Indium, Aryl Indium, Indium(III) Myristate, Indium(III) Myristate Acetate and Indium(III) Myristate Acetate and Indium(III) ) Myristate 2 Acetate) may be any one selected from the group consisting of, preferably indium acetylacetonate (Indium(III) acetylacetonate).

As the active metal precursor, a compound containing an active metal may be used without limitation, and the active metal is selected from the group consisting of Zn, Mn, Cu, Fe, Ni, Co, Cr, Ti, Zr, Nb, Mo, and Ru. At least one or more metals to be used may be used. For example, when the active metal is Zn, zinc acetate, Zn (acac) (Zn (acetylacetonate)) or the like may be used. In this case, there is an advantage in that In-Zn carboxylate is easily synthesized when an acac-based precursor is used than zinc acetate (Zn acetate).

The solvent of step 3-1 is, for example, 2,6,10,15,19,23-hexamethyltetracoic acid (Squalane), 1-octadecene (ODE), trioctylamine (TOA), tributylphosphine It may be at least one selected from the group consisting of oxide, octadecene, octadecylamine, trioctylphosphine (TOP), and trioctylphosphine oxide (TOPO).

Step 3-2 is a step of reacting for 50 to 100 minutes after raising the temperature to α temperature for 5 to 20 minutes while decompressing the solution of step 3-1. α temperature may be, for example, 100 ℃ to 150 ℃, is preferably 110 ℃ to 130 ℃. The reason for raising the temperature and reducing the pressure in this step is to remove a small amount of impurities remaining in the precursor and simultaneously synthesize In-Zn carboxylate. If the temperature is higher than the above temperature range, the concentration of the solvent may change due to a different amount of the solvent. If the temperature is lower than the above temperature, impurities may not be properly removed.

Step 3-3 is a step of replacing the solution of step 3-2 with an inert atmosphere and then raising the temperature to β temperature. The β temperature is preferably around 250°C to 300°C in consideration of the reactivity of the group V precursor to be added later for instant seed generation.

Step 3-4 is a step of injecting a group V element precursor solution into the solution of step 3-3 and reacting for 10 to 100 minutes at room temperature (25°C). This room temperature condition is to prevent In-Zn-P from becoming particles due to the high reactivity of the group V element precursor.

The Group V element precursor solution in Step 3-3 contains a Group V element precursor and a solvent. Group V element precursors are, for example, organometallics such as tris(trimethylsilyl)phosphine (TMSP), amino phosphine, white phosphorus, tri(pyrazolyl)phosphane), and calcium phosphide. Organometallic phosphorus can be used.

At this time, an alkylphosphine-based surfactant can be added to the group V element precursor solution, and when used together, a new organic complex is formed by combining the group V element and the alkylphosphine-based surfactant. The reaction is possible, making it more suitable for mass production. The size of the quantum dots may be adjusted according to the type of the alkylphosphine surfactant.

An alkylphosphine surfactant can be added to the group V element precursor solution, and when used together, a new organic complex is formed by combining the group V element and the alkylphosphine surfactant, thereby enabling a more stable reaction and mass production. Becomes more suitable for The size of the quantum dots may be adjusted according to the type of the alkylphosphine surfactant.

The alkylphosphine-based surfactant is not limited thereto, but triethyl phosphine, tributyl phosphine, trioctyl phosphine, triphenyl phosphine, and triphenyl phosphine. It may be one or more selected from the group consisting of cyclohexyl phosphine.

In addition, the solvent for the group V element precursor solution may be, for example, TOP, TBP, ODE, amines (primary amine, secondary amine, third amine), etc., and the molar concentration of the group V element precursor solution is 0.001M to 2M Is preferred.

At this time, it is preferable that the molar ratio of the group III element and the active metal is 1:0.2 to 1:0.8. Preferably, it may be 1:0.3 to 1:0.6. If the molar ratio of the group III element and the active metal does not satisfy the above range, it may not be able to effectively prevent lattice mismatch and thus provide a change in quantum efficiency.

The molar ratio of the active metal to the group V element is preferably 1:1 to 1:1.5, for example. In the case of a molar ratio outside the above range, there may be a problem in that non-uniform quantum dots are synthesized because the growth of the growth layer does not occur evenly.

The additional elements included in the growth layer may be separately included, or additional elements in which the additional elements included during seed formation may be unreacted may be included. For example, when an additional element is to be injected into the growth layer, 1) a precursor containing the additional element is injected before the growth layer is injected, or 2) a seed is formed with a group V element. An example of the latter is a method of forming a seed by mixing a GaCl3-toluene solution with a TOP-TMSP solution.

The shell formation step is a step of forming a shell on the surface of the growth layer after the growth layer formation step. The shell forming step includes steps 4-1, 4-2, and 4-3. The shell forming step may be the same as step 4-1, step 4-2, and step 4-3 as described in the fourth aspect of the present invention, and a detailed description thereof will be omitted.

The purification step includes step 5-1, step 5-2, and step 5-3. The refining step may also be the same as step 5-1, step 5-2, and step 5-3, as described in the fourth aspect of the present invention, and a detailed description will be omitted.

Hereinafter, embodiments of the present invention will be described in more detail. Examples to be described later are intended to illustrate the present invention, but are not intended to limit the present invention.

<Example>

<Example 1: Preparation of Zn-OXO>

Preparation of active nanocluster solution

1.Zn acetate and oleic acid are put in a 250ml three neck flask, heated to 120 ^o C under reduced pressure at room temperature, and filled with an inert gas after 1 hour to create a Zn (Oleate) ₂ solution. I did.

2. The resulting Zn (Oleate) ₂ solution was heated to a high temperature to prepare an active nanocluster.

3. Then, Octadecene was injected and the temperature was reduced to room temperature, and the concentration of the mixed solution was 0.5M.

<Example 2: Cu-OXO preparation>

Preparation of active nanocluster solution

1. Put copper acetate (Cu(Ⅱ) acetate) and oleic acid in a 250ml three neck flask, heat it to 120 ^o C under reduced pressure at room temperature, and fill it with an inert gas after 1 hour to make Cu(Oleate) ₂ A solution was created.

2. The resulting Cu (Oleate) ₂ solution was heated to a high temperature to prepare an active nanocluster.

3. Then, Octadecene was injected and the temperature was reduced to room temperature, and the concentration of the mixed solution was 0.5M.

<Example 3: Preparation of InZnP Composite Solution Used for Growth Layer>

1. Indium acetate, Zn acetate, oleic acid, and octadecene were added to the three neck flask and stirred.

2. The solution was heated to 120 ^o C while reducing pressure to react.

3. After replacing the solution with an inert gas, the temperature was reduced.

4. Tris (trimethylsilyl) phosphine (Tris (trimethylsilyl) phosphine, TMSP) was injected into the solution, and the solution thus prepared is referred to as an In-Zn-P complex solution.

<Example 4: InZnP@ZnSeS quantum dots using Zn-OXO>

InZnP@ZnSeS quantum dots were prepared as follows using the Zn-OXO activated nanocluster solution synthesized in Example 1.

1. In a three neck flask, octadecene (ODE), an active nanocluster, and an In precursor were added and stirred. At this time, the concentration of each precursor was 0.1mmol In and 2mmol Zn.

2. The solution was reacted at 120 ^o C for 1 hour under reduced pressure.

3. After filling the solution with an inert gas, tris(trimethylsilyl)phosphine (TMSP) was injected at 280 ^° C. At this time, the molar ratio of In and P was 1:0.7.

4. After reacting the solution at 280 ^° C for 1 hour, the temperature was reduced to prepare InZnP seeds.

5. The above InZnP seed was reacted by injecting a TOP-Se solution in which selenium was dissolved in trioctylphosphine as a shell material and a TOP-S solution in which sulfur was dissolved in trioctylphosphine.

6. The obtained quantum dots were put in acetone or ethanol and centrifuged.

7. After centrifugation, the precipitate was dispersed in hexane (1-Hexane) to obtain a quantum dot solution.

<Example 5: InZnP/InZnP growth@ZnSeS quantum dots using Zn-OXO>

InZnP/InZnP growth@ZnSeS quantum dots were prepared as follows using the Zn-OXO activated nanocluster solution synthesized in Example 1.

1. In a three neck flask, octadecene (ODE), an active nanocluster, and an In precursor were added and stirred. At this time, the concentration of each precursor was 0.1mmol In and 2mmol Zn.

2. The solution was reacted at 120 ^o C for 1 hour under reduced pressure.

3. After filling the solution with an inert gas, tris(trimethylsilyl)phosphine (TMSP) was injected at 280 ^° C. At this time, the molar ratio of In and P was 1:0.7.

4. After reacting the solution at 280 ^° C for 1 hour, the temperature was reduced to prepare InZnP seeds.

5. 5 mL of the In-Zn-P complex solution prepared in (Preparation Example 4) was injected into the InZnP seed.

6. When the injection was replaced with an inert gas, quantum dots having an InZnP growth layer included in the band gap control layer on the InZnP seed included in the band gap control layer were manufactured.

7. The prepared InZnP/InZnP quantum dot solution was reacted by injecting a TOP-Se solution in which selenium was dissolved in trioctylphosphine as a shell material and a TOP-S solution in which sulfur was dissolved in trioctylphosphine.

8. The obtained quantum dots were put in acetone or ethanol and centrifuged.

9. After centrifugation, the precipitate was dispersed in hexane (1-Hexane) to obtain a quantum dot solution.

<Example 6: InZnGaP@ZnSeS quantum dots using Zn-OXO>

InZnGaP@ZnSeS quantum dots were prepared as follows using the Zn-OXO activated nanocluster solution synthesized in Example 1.

1. In a three neck flask, Octadecene (ODE), an active nanocluster solution, and an In precursor were added and stirred. At this time, the concentration of each precursor was 0.1mmol In and 2mmol Zn.

2. The solution was reacted at 120 ^o C for 1 hour under reduced pressure.

3. After filling the solution with an inert gas, tris (trimethylsilyl) phosphine (TMSP) and gallium chloride were injected at 280 ^° C. At this time, the molar ratio of In, P, and Ga was 1:0.7:0.5.

4. After reacting the solution at 280 ^° C. for 1 hour, the temperature was reduced to prepare InZnGaP seeds.

5. The above InZnP seed was reacted by injecting a TOP-Se solution in which selenium was dissolved in trioctylphosphine as a shell material and a TOP-S solution in which sulfur was dissolved in trioctylphosphine.

6. The obtained quantum dots were put in acetone or ethanol and centrifuged.

7. After centrifugation, the precipitate was dispersed in hexane (1-Hexane) to obtain a quantum dot solution.

<Example 7: InZnGaP/InZnP growth@ZnSeS quantum dots using Zn-OXO>

Using the Zn-OXO active nanocluster solution synthesized in Example 1, InZnGaP/InZnP growth@ZnSeS quantum dots were prepared as follows.

1. In a three neck flask, octadecene (ODE), an active nanocluster, and an In precursor were added and stirred. At this time, the concentration of each precursor was 0.1mmol In and 2mmol Zn.

2. The solution was reacted at 120 ^o C for 1 hour under reduced pressure.

3. After filling the solution with an inert gas, tris (trimethylsilyl) phosphine (TMSP) and gallium chloride were injected at 280 ^° C. At this time, the molar ratio of In, P, and Ga was 1:0.7:0.5.

4. After reacting the solution at 280 ^° C. for 1 hour, the temperature was reduced to prepare InZnGaP seeds included in the band gap control layer.

5. 5 mL of the In-Zn-P complex solution prepared in (Preparation Example 4) was injected into the InZnP seed.

6. When the injection was replaced with an inert gas, quantum dots having an InZnP growth layer included in the band gap control layer on the InZnGaP seed included in the band gap control layer were manufactured.

7. The prepared InZnGaP/InZnP quantum dot solution was reacted by injecting a TOP-Se solution in which selenium was dissolved in trioctylphosphine as a shell material and a TOP-S solution in which sulfur was dissolved in trioctylphosphine.

8. The obtained quantum dots were put in acetone or ethanol and centrifuged.

9. After centrifugation, the precipitate was dispersed in hexane (1-Hexane) to obtain a quantum dot solution.

<Example 8: InZnP@ZnSeS quantum dots using Zn-OXO>

InZnP@ZnSeS quantum dots were prepared in the same manner as in Example 4 using the active nanocluster solution synthesized in Example 1. At this time, the concentration of each precursor was all the same as in Example 1 except that the concentration of In: 0.1 mmol, Zn: 0.25 mmol.

<Example 9: InZnP@ZnSeS quantum dots using Zn-OXO>

InZnP@ZnSeS quantum dots were prepared in the same manner as in Example 4 using the active nanocluster solution synthesized in Example 1. At this time, the concentration of each precursor was the same as in Example 1, except that the concentration of In: 0.1 mmol, Zn: 6.25 mmol.

<Example 10: InZnP/InZnP growth@ZnSeS quantum dots using Zn-OXO>

A quantum dot including a band gap control layer was prepared in the same manner as in Example 5, except that an In-P composite solution without Zn acetate was prepared and used in the In-Zn-P composite solution of Example 3.

<Example 11: InZnP/InZnP growth@ZnSeS quantum dots using Zn-OXO>

A band gap control layer was included in the same manner as in Example 5, except that 2.5 mmol of Zn acetate was added to the In-Zn-P composite solution of Example 3 instead of 0.5 mmol to prepare an In-Zn-P composite solution. Quantum dots were prepared.

<Comparative Example>

<Comparative Example 1: Preparation of Zn (Oleate) ₂ >

1.Zn acetate and oleic acid are placed in a 250ml three neck flask, heated to 120 ^o C under reduced pressure at room temperature, and filled with an inert gas after 1 hour to create a Zn (Oleate) ₂ solution. Did

<Comparative Example 2: InZnP@ZnSeS quantum dots using Zn Oleate>

Quantum dots were prepared in the same manner as in Example 4, except that the active nanocluster solution of <Zn-OXO> in Example 4 was replaced with the zinc oleate solution synthesized in Comparative Example 1.

<Comparative Example 3: InZnP/InZnP growth@ZnSeS quantum dots using Zn-Oleate>

Quantum dots were prepared in the same manner as in Example 5, except that the active nanocluster solution of <Zn-OXO> in Example 5 was replaced with the zinc oleate solution synthesized in Comparative Example 1.

<Comparative Example 4: InZnGaP@ZnSeS quantum dots using Zn-Oleate>

Quantum dots were prepared in the same manner as in Example 6, except that the active nanocluster solution of <Zn-OXO> in Example 6 was replaced with the zinc oleate solution synthesized in Comparative Example 1.

<Comparative Example 5: InZnGaP/InZnP growth@ZnSeS quantum dots using Zn oleate>

Quantum dots were prepared in the same manner as in Example 7, except that the active nanocluster solution of <Zn-OXO> in Example 7 was replaced with the zinc oleate solution synthesized in Comparative Example 1.

<Experimental Example>

<Experimental Example 1>

In order to confirm the active nanoclusters according to the activation of the active metal, MALDI-TOP data for the active nanocluster solution prepared in Example 1 was obtained and shown in FIG. 2.

Figure 2 specifically shows the weight change according to the activation of the active metal precursor (Zn (oleate) ₂ ), when activated, at 1683 m/z and 3020 m/z as in the red graph as well as 975 m/z shown in the existing black graph. Peaks are formed, and as a result of analyzing the 1683m/z and 3020m/z peaks at this time, it was found that they correspond to Zn ₄ O (carboxylate) ₆ and Zn ₇ O ₂ (carboxylate) ₁₀ . From this, it was confirmed that active nanoclusters were synthesized by activating the active metal precursor.

In addition, as a result of confirming the ratio of active metal-carboxylate and active metal oxide-carboxylate by the integrated value of each peak, it was found that the active metal oxide-carboxylate was contained in a weight ratio of approximately 20:80. Could

<Experimental Example 2>

The quantum dots of Example 4 and the quantum dots of Comparative Example 2 were prepared, and UV and PL spectra were measured and shown in FIG. 4. In addition, UV and PL spectra of the seed of the quantum dots of Example 4 of the present invention and the seed of the quantum dots of Comparative Example 2 were measured and shown in FIG. 3. In addition, Figure 4 is a graph obtained by measuring the UV and PL spectrum by preparing the quantum dot of Example 4 and the quantum dot of Comparative Example 2 of the present invention.

According to FIGS. 3 and 4, it was confirmed that Example 4 had quantum dots having a smaller size and uniformity and high quantum efficiency compared to Comparative Example 2 due to the use of active nanoclusters.

<Experimental Example 3>

The quantum dots of Example 5 and the quantum dots of Comparative Example 3 were prepared, and UV and PL spectra were measured and shown in FIG. 5. In addition, in the quantum dot of Example 5 of the present invention, a graph measuring the PL spectrum of each step of seed, growth, and shell formation is shown in FIG. 6.

According to FIG. 5, it was confirmed that in Example 5, due to the use of active nanoclusters, quantum dots including a bandgap control layer having a smaller size and uniformity and an improved half-value width compared to Comparative Example 3 were prepared.

In addition, as shown in FIG. 6, the maximum change in emission was confirmed by a right shift.

<Experimental Example 4>

The quantum dots obtained by Examples 4 to 7 and the quantum dots obtained by Comparative Examples 2 to 5 were dissolved in Toluene, respectively, and analyzed by light irradiation at a wavelength of 450 nm using Otsuka Electronics QE-2000 [luminescence Wavelength peak (Emission peak), quantum efficiency (Quantum Yield), full width at half maximum (FWHM)] was confirmed. The measurement results are shown in Table 1 and FIGS. 4 to 6.

division	Emission peak (nm)	FWHM (nm)	Q.Y.(%)
Example 4	530	39	94
Example 5	621	45	84
Example 6	535	38	96
Example 7	625	44	88
Comparative Example 2	535	56	75
Comparative Example 3	622	60	72
Comparative Example 4	541	56	80
Comparative Example 5	627	57	80

As can be seen from the results of Table 1, the quantum dots of Examples 4 to 7 using an active nanocluster have a narrow half width compared to the quantum dots of Comparative Examples 2 to 5 using zinc oleate instead of the active nanocluster, and have excellent luminous efficiency. . Specifically, in the case of the quantum dots of Example 4 using active nanoclusters but not including additional elements, the half width was significantly improved compared to the quantum dots of Comparative Example 2, which did not contain additional elements and used zinc oleate instead of the active nanocluster. Has increased. That is, when the active nanocluster was used, it was confirmed that the half width was remarkably improved and the luminous efficiency was increased.

In addition, both the quantum dots of Example 4 and the quantum dots of Comparative Example 2 showed emission maximums of 500 nm to 550 nm, of which, in the case of Example 4, the emission maximum shifted to the right compared to the quantum dots of Comparative Example 2 It was confirmed that the half width and luminous efficiency were also improved.

In addition, the quantum dots of Example 6 containing an additional element and using an active nanocluster according to the present invention have a narrow half width compared to the quantum dots of Comparative Example 4 that contain the additional element and use zinc oleate instead of the active nanocluster, and have excellent light emission. Showed efficiency.

For reference, in the case of the quantum dots of Comparative Example 4 in which zinc oleate was used instead of the active nanocluster, although the additional element was included, only the luminous efficiency was small compared to the quantum dots of Comparative Example 2 in which zinc oleate was used instead of the active nanocluster without including the additional element Increasing results were confirmed.

In addition, when comparing the quantum dots of Example 7 of the present invention using each of the active nanoclusters and the quantum dots of Example 4, there is a difference that Example 7 contains an additional element, and looking at the measurement results, the luminous efficiency is slightly improved. Can be confirmed.

In addition, when comparing the quantum dots of Example 5 of the present invention including the growth layer and the quantum dots of Example 7, there is a difference that Example 7 contains an additional element, and the measurement results show that the luminous efficiency is slightly improved. I can confirm.

As a result, it can be seen that, in the case of the quantum dots of Examples 4 to 7 according to the present invention, remarkably excellent results in terms of half width and luminous efficiency compared to the quantum dots of Comparative Examples 2 to 5.

<Experimental Example 5>

The photoluminescence data analyzed by dissolving the quantum dots of Example 8 and Example 9 prepared by varying the content of the group III element and the active metal in the seed in Toluene and irradiating with light at 450 nm wavelength using Otsuka Electronics QE-2000 [luminescence Wavelength peak (Emission peak), quantum efficiency (Quantum Yield), full width at half maximum (FWHM)] was confirmed. The measurement results are shown in Table 2.

division	In:Zn content ratio of seed	Emission peak (nm)	FWHM (nm)	Q.Y.(%)
Example 4	1:8	530	39	94
Example 8	1:1	545	45	20
Example 9	1:25	527	43	80

As can be seen from the results of Table 2, when comparing the quantum dots of Example 4 and the quantum dots of Examples 8 and 9, the difference in half width and luminous efficiency due to the difference in the content ratio of the group III element and the active metal constituting the seed It could be confirmed that it occurred.

<Experimental Example 6>

Photoluminescence analyzed by dissolving the quantum dots of Example 10 and Example 11 prepared by varying the content of the group III element and the active metal in the bandgap control layer in Toluene and irradiating with light at 450 nm wavelength using Otsuka Electronics QE-2000 The data [emission peak, quantum efficiency, full width at half maximum, FWHM] were confirmed. The measurement results are shown in Table 3.

division	In:Zn content ratio of the band gap control layer	Emission peak (nm)	FWHM (nm)	Q.Y.(%)
Example 5	1:0.7	621	45	84
Example 10	1:0.1	626	52	61
Example 11	1:2.6	620	50	72

As can be seen from the results of Table 3, when comparing the quantum dots of Example 5 and the quantum dots of Examples 10 and 11, due to the difference in the content ratio of the group III element and the active metal constituting the bandgap control layer, the half width and luminous efficiency were increased. It was confirmed that there was a difference.

Features, structures, effects, and the like illustrated in each of the above-described embodiments may be combined or modified for other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Accordingly, contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

Claims (11)

1. A seed containing a Group III element and a Group V element; And a growth layer including a group III element and a group V element formed on an outer surface of the seed. It has a bandgap control layer comprising a,

   A group III-V quantum dot comprising an active metal capable of having various oxidation numbers in at least one of the seed or growth layer constituting the bandgap control layer.
2. The group III-V quantum dot according to claim 1, wherein the active metal is selected from the group consisting of Zn, Mn, Cu, Fe, Ni, Co, Cr, Ti, Zr, Nb, Mo, Ru, and combinations thereof.
3. The group III-V quantum dot according to claim 1, wherein the molar ratio of the active metal to the group III element in the bandgap control layer is 1:0.2 to 1:2.
4. The group III-V quantum dot according to claim 1, wherein the molar ratio of the active metal to the group III element in the band gap control layer is 1:0.2 to 1:1.
5. The group III-V quantum dot according to claim 1, wherein the molar ratio of the active metal and the group V element in the bandgap control layer is 1:1 to 1:1.5.
6. The group III-V quantum dot according to claim 1, wherein the thickness of the growth layer included in the band gap control layer is 0.5 nm to 2.5 nm.
7. The group III-V quantum dot according to claim 1, wherein the growth layer included in the band gap control layer further includes at least one additional element selected from the group consisting of Al, Ga, Ti, Mg, Na, Li, and Cu. .
8. The group III-V quantum dot according to claim 1, comprising at least one shell on an outer surface of the growth layer included in the band gap control layer.
9. The method of claim 8, wherein the shell is CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, PbS, PbSe, PbSeS, PbTe, GaAs, GaP, InP, InGaP, InZnP, InAs, CuS, InN, GaN, InGaN , AlP, AlAs, InAs, GaSb, InSb, AlSb, HgS, HgTe, HgCdTe, ZnCdS, ZnCdSe, CdSeTe, CuInSe2, CuInS2, AgInS2, and at least one group III-V quantum dot selected from the group consisting of SnTe.
10. A seed forming step of injecting a group III element precursor and a group V element precursor solution into a solution containing an active metal oxide-carboxylate to form a seed in which the active metal, the group III element, and the group V element are alloyed; And a growth layer forming step of forming a growth layer of a group III element-active metal-group V element complex solution after the seed formation step; and a method of manufacturing a group III-V quantum dot having a band gap control layer comprising: a.
11. 11. The method of claim 10, wherein the active metal oxide-carboxylate has a band gap control layer comprising a compound of Formula 1 below.

    [Formula 1]

    T _x O _y (Carboxylate) _z

    In Formula 1, T is an active metal, x, y, and z are natural numbers, and x>y.

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