KR20190136881A - METHOD FOR MANUFACTURING InP/ZnS CORE-SHELL QUANTUM DOTS AND InP/ZnS CORE-SHELL QUANTUM DOTS USING THEREOF - Google Patents

Abstract

The present invention relates to a method for producing InP/ZnS core-shell quantum dots and the InP/ZnS core-shell quantum dots produced thereby and, more specifically, to a method for producing InP/ZnS core-shell quantum dots through a single precursor injection. The InP/ZnS core-shell quantum dot producing method by an embodiment of the present invention includes: a first precursor solution producing step of, to a preset temperature, heating first precursor solution produced by dissolving first and second precursors forming the core of quantum dots and a third precursor forming the shell of quantum dots in a first solvent; a second precursor solution producing step of producing second precursor solution by dissolving a fourth precursor forming shells with the third precursor in a second solvent; a mixed solution producing step of producing mixed solution by mixing the heated first precursor solution with the second precursor solution; and a mixed solution heating step of producing quantum dots formed with an InP core and a ZnS shell by heating the mixed solution at a preset temperature. The present invention is able to produce the InP/ZnS core-shell quantum dots by a simple process.

Description

METHOD FOR MANUFACTURING INP / ZnS CORE-SHELL QUANTUM DOTS AND InP / ZnS CORE-SHELL QUANTUM DOTS USING THEREOF}

The present invention relates to a method for manufacturing quantum dots, and more particularly, to a method for manufacturing InP / ZnS core-shell quantum dots through a single injection of a precursor.

Quantum dots are self-illuminating nano-sized semiconductor materials, in which electrons within the quantum dots quantum jump to higher energy levels when they absorb energy and fall to lower energy levels when they emit energy. By repeating this, various colors are emitted at wavelengths in the form of energy. The quantum dots can control the energy band gap by controlling the size, shape, and chemical composition, and can control the factors to obtain quantum dots of various emission wavelengths. Accordingly, quantum dots have been applied to various industrial fields requiring light emitting devices such as ultra-fine semiconductors, disease diagnosis reagents, and displays.

Meanwhile, in order to form a shell on an outer circumferential surface of a quantum dot core, a precursor material for forming a shell is added to a solution obtained by mixing and heating a precursor material for forming a core to synthesize a core. After the quantum dot of the core-shell structure was prepared. However, in the prior art, since a cleaning process for removing reaction by-products after synthesis of a core is required, the process is complicated.

Republic of Korea Patent Publication No. 10-1788786 (Name: Semiconductor quantum dots alloyed with III-V / zinc chalcogen compound) Republic of Korea Patent Publication No. 10-1088108 (Name: InP / ZnS core / shell quantum dot synthesis method using a solvent heat method)

The present invention is to solve the problems of the prior art as described above, the object of the present invention, InP / ZnS core-shell InP / ZnS core-shell is configured to prevent surface defects (defect) on the surface of the quantum dot It is to provide a quantum dot manufacturing method and the InP / ZnS core-shell quantum dot produced thereby.

It is another object of the present invention to provide an InP / ZnS core-shell quantum dot manufacturing method and InP / ZnS core-shell quantum dot manufactured thereby, which are configured to produce InP / ZnS core-shell quantum dots in a simpler process. .

Another object of the present invention is to prepare an InP / ZnS core-shell quantum dot that can be prepared for long-term preservation without the solidification of the quantum dot InP / ZnS core-shell quantum dot and InP / ZnS core-shell quantum dot produced thereby To provide.

A method of manufacturing an InP / ZnS core-shell quantum dot and an InP / ZnS core-shell quantum dot produced thereby to achieve the above object, the first and second precursor and a shell of the quantum dot forming the core of the quantum dot Preparing a first precursor solution in which the third precursor to be formed is dissolved in a first solvent and heated to a predetermined temperature; Preparing a second precursor solution in which a fourth precursor forming a shell together with the third precursor is dissolved in a second solvent to prepare a second precursor solution; A mixed solution preparation step of mixing the heated first precursor solution and the second precursor solution to prepare a mixed solution; A mixed solution heating step in which the mixed solution is heated to a predetermined temperature to produce a quantum dot composed of an InP core and a ZnS shell; It includes.

In the preparing of the first precursor solution, the first precursor may include Indium (II) chloride, Indium (III) iodide, Indium (I) bromide, Indium (I) iodide, Indium (III) oxide, Indium (III) ) Nitride, Indium (III) acetate, Indium (III) acetylacetonate, Indium (III) chloride tetrahydrate, Indium (III) nitrate hydrate, Indium (III) chloride hydrate, Indium (III) sulfate, Indium (III) acetate hydrate It may be any one selected from the group.

In addition, in the preparing of the first precursor solution, the second precursor is any one selected from the group consisting of trioctylphosphine oxide, hexylphosphonic acid, trioctylphosphine, tris (trimethylsilyl) phosphine, diphenylpropylphosphine, tributylphosphine, triphenylphosphite, and tetradecylphosphonic acid. Can be.

In the preparing of the first precursor solution, the third precursor may be sulfur in a powder form.

In addition, in the first precursor solution manufacturing step, the first solvent is Oleylamine, octadecylamine, hexadecylamine, dodecylamine, oleic acid, 1-octadecene, 1-hexadecene, 1-eicosene, eicosane, octadecane, hexadecane, tetradecane, squalene, It may be any one selected from the group consisting of dodecanethiol.

In the preparing of the first precursor solution, the first precursor solution may be heated to a temperature ranging from 140 ° C. to 220 ° C.

Also, in the preparing of the second precursor solution, the fourth precursor may be zinc undecylenate.

In the preparing of the second precursor solution, the second solvent is Oleylamine, octadecylamine, hexadecylamine, dodecylamine, oleic acid, 1-octadecene, 1-hexadecene, 1-eicosene, eicosane, octadecane, hexadecane, tetradecane, squalene, It may be any one selected from the group consisting of dodecanethiol.

In addition, in the mixed solution heating step, the mixed first and second precursor solutions may be heated to a temperature of 280 ℃.

According to the InP / ZnS core-shell quantum dot manufacturing method and InP / ZnS core-shell quantum dot produced by the embodiment of the present invention, the following effects can be expected.

First, in the embodiment of the present invention, the first precursor solution is a mixture of the first and second precursors forming the core of the quantum dots and the third precursor forming the shell is heated to form the core of the quantum dots. Therefore, according to the embodiment of the present invention, by forming a shell composed of the third precursor on the outer peripheral surface of the core, it is possible to manufacture an InP / ZnS core-shell quantum dot that can prevent the surface defect (defect).

In an embodiment of the present invention, after the first precursor solution in which In and P precursors forming the core of the quantum dots and the S precursor forming the shell are heated, a quantum dot having a Sulfur ligand bonded to the InP core is prepared. In addition, a Zn precursor solution forming a shell together with the S precursor in the quantum dot is mixed and reheated to prepare an InP / ZnS core-shell quantum dot. Therefore, according to the embodiment of the present invention, InP core without a separate cleaning process to remove the reaction by-products that may react with the S and Zn precursor solution added to synthesize the shell in the solution after the synthesis of InP core / ZnS core-shell quantum dots can be prepared.

In the embodiment of the present invention, as a fourth precursor constituting the shell of the quantum dots, Zinc Undecylenate having a low viscosity is used. Therefore, according to the embodiment of the present invention, InP / ZnS core-shell quantum dots capable of long term storage without solidification can be prepared.

1 is a flow chart showing a method of manufacturing an InP / ZnS core-shell quantum dot according to an embodiment of the present invention.
Figure 2 is a graph analyzing the ΔG ° value according to the temperature according to the preparation example of the present invention.
3 to 5 are PL (Photo Luminescence) graphs of the emission intensity of InP / ZnS core-shell quantum dots prepared by Preparation Examples and Comparative Examples 1 and 2 of the present invention.
Figure 6 is a photograph showing the degree of solidification after 90 days storage of the InP / ZnS core-shell quantum dots prepared by Preparation Example and Comparative Example 3 of the present invention.

Hereinafter, an InP / ZnS core-shell quantum dot manufacturing method according to an embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

Referring to Figure 1, InP / ZnS core-shell quantum dot manufacturing method according to the present embodiment, the first precursor solution manufacturing step (S100), the second precursor solution manufacturing step (S200), the mixed solution manufacturing step (S300) and Mixed solution heating step (S400) is included.

More specifically, in the first precursor solution manufacturing step (S100), the first and second precursors forming the core of the quantum dots and the third precursor forming the shell of the quantum dots is prepared by dissolving in the first solvent One precursor solution is heated to a predetermined temperature. In this case, the first precursor is Indium (II) chloride, Indium (III) iodide, Indium (I) bromide, Indium (I) iodide, Indium (III) oxide, Indium (III) nitride, Indium (III) acetate Any one selected from the group consisting of Indium (III) acetylacetonate, Indium (III) chloride tetrahydrate, Indium (III) nitrate hydrate, Indium (III) chloride hydrate, Indium (III) sulfate, and Indium (III) acetate hydrate The second precursor may be any one selected from the group consisting of trioctylphosphine oxide, hexylphosphonic acid, trioctylphosphine, tris (trimethylsilyl) phosphine, diphenylpropylphosphine, tributylphosphine, triphenylphosphite, and tetradecylphosphonic acid. In addition, the third precursor may be sulfur in powder form, and the first solvent may be Oleylamine, octadecylamine, hexadecylamine, dodecylamine, oleic acid, 1-octadecene, 1-hexadecene, 1-eicosene, eicosane, It may be any one selected from the group consisting of octadecane, hexadecane, tetradecane, squalene, dodecanethiol. In addition, the first precursor solution may be heated to a temperature in the range of 140 ° C to 220 ° C. For example, the first precursor solution manufacturing step (S100), Indium (II) chloride and trioctylphosphine oxide to form a core of the quantum dots, Sulfur (Sulfur) to form a shell of the quantum dots is prepared by dissolving in Oleylamine One precursor solution may be heated to 160 ° C. to prepare a first precursor solution.

In addition, in the second precursor solution manufacturing step (S200), the fourth precursor forming the shell together with the third precursor is dissolved in a second solvent to prepare a second precursor solution. In this case, the fourth precursor may be Zinc undecylenate, and the second solvent may be Oleylamine, octadecylamine, hexadecylamine, dodecylamine, oleic acid, 1-octadecene, 1-hexadecene, 1-eicosene, eicosane, octadecane, hexadecane, It may be any one selected from the group consisting of tetradecane, squalene, dodecanethiol. For example, in the second precursor solution manufacturing step (S200), zinc undecylenate may be dissolved in Oleylamine to prepare a second precursor solution.

In the mixed solution preparing step (S300), the heated first precursor solution and the second precursor solution are mixed to prepare a mixed solution.

Finally, in the mixed solution heating step (S400), the mixed solution is heated to a predetermined temperature to produce a quantum dot composed of an InP core and a ZnS shell. In this case, the mixed first and second precursor solutions may be heated to a temperature of 280 ℃.

Hereinafter, the present invention will be described in more detail with reference to production examples. These preparations are merely for illustrating the present invention in detail, and it will be apparent to those skilled in the art that the scope of the present invention is not limited to these preparations.

Production Example

<Production example>

In Preparation Example 1, the first precursor solution prepared by dissolving Indium (II) chloride, trioctylphosphine oxide and sulfur powder in Oleylamine was heated at 160 ° C. in the first precursor solution preparation step (S100).

Next, in the second precursor solution preparation step (S200), Zinc undecylenate was dissolved in Oleylamine to prepare a second precursor solution.

In the mixed solution preparation step (S300), the first precursor solution and the second precursor solution are mixed to prepare a mixed solution.

Finally, in the mixed solution heating step (S400), the mixed solution was heated to a temperature of 280 ℃ to produce a quantum dot consisting of the InP core and ZnS shell.

Comparative Example 1

In Comparative Example 1, InP / ZnS core-shell quantum dots were prepared in the same manner as in Preparation Example 1, but in the first precursor solution preparing step (S100), the first precursor solution was heated at 120 ° C.

Comparative Example 2

In Comparative Example 2, InS / ZnS quantum dots were prepared in the same manner as in Preparation Example 1, but in the first precursor solution preparation step (S100), the first precursor solution was heated at 240 ° C.

Comparative Example 3

In Comparative Example 3, InS / ZnS quantum dots were prepared in the same manner as in Preparation Example 1, but a second precursor solution was prepared by dissolving zinc stearate in Oleylamine as a second precursor solution preparing step (S200) and a fourth precursor.

Experimental Example

Experimental Example 1

Indium mixed with the first to fourth precursors in the preparation example. ΔG ° (Gibbs free energy change) analysis was performed on the chemical reactions of Phosphorus, Sulfur and Zinc, and the results are attached to FIG. 2.

Referring to FIG. 2, when the first precursor solution is in the range of the heating temperature and the mixed solution heating temperature, 140 ° C. to 280 ° C., the ΔG ° value of the reaction in which InP and Phosphorus react to generate InP produces the highest negative value. Have That is, in the step of preparing the first precursor solution (S100), Indium and Phosphorus added as the first and second precursors were reacted to synthesize an InP quantum dot core, and the Sulfur ligand added as the third precursor was bound to the InP core surface. You can check the status.

Experimental Example 2

Photo Luminescence (PL) analysis was performed on the InP / ZnS core-shell quantum dots prepared by Preparation Examples and Comparative Examples 1 and 2, and the results are attached to FIGS. 3 to 5.

Referring to FIGS. 3 to 5, InP / ZnS core-shell quantum dots having a strong luminescence intensity were manufactured in the case of the preparation example, but InP / ZnS core-shell quantum dots having lower strength than the preparation example were prepared in Comparative Examples 1 and 2. It became. Therefore, in the case of the preparation example, it can be seen that the InP / ZnS core-shell quantum dot is stronger than the Comparative Examples 1 and 2.

Experimental Example 3

The viscosity after storing the InP / ZnS core-shell quantum dots prepared by Preparation Example and Comparative Example 3 for three months was compared, and the results are attached to FIG. 6.

Referring to FIG. 6, in the preparation example, coagulation of the quantum dots was hardly achieved, but in the case of Comparative Example 3, coagulation proceeded to increase the viscosity of the quantum dots. Therefore, in the case of the preparation example, solidification of the prepared quantum dots does not proceed as compared with Comparative Example 3, it can be confirmed that the InP / ZnS core-shell quantum dots can be stored for a long time.

Claims (10)

A first precursor solution forming a core of the quantum dots and a third precursor forming a shell of the quantum dots are dissolved in a first solvent and heated to a predetermined temperature to prepare a first precursor solution (S100);
A fourth precursor forming a shell together with the third precursor is dissolved in a second solvent to prepare a second precursor solution (S200);
Mixing the heated first precursor solution with the second precursor solution to produce a mixed solution (S300); And
The mixed solution is heated to a predetermined temperature for the production of quantum dots consisting of InP core and ZnS shell (S400); InP / ZnS core-shell quantum dot manufacturing method comprising a.
The method of claim 1,
In the first precursor solution manufacturing step (S100),
The first precursor is Indium (II) chloride, Indium (III) iodide, Indium (I) bromide, Indium (I) iodide, Indium (III) oxide, Indium (III) nitride, Indium (III) acetate, Indium ( III) InP / which is selected from the group consisting of acetylacetonate, Indium (III) chloride tetrahydrate, Indium (III) nitrate hydrate, Indium (III) chloride hydrate, Indium (III) sulfate, Indium (III) acetate hydrate ZnS core-shell quantum dot manufacturing method.
The method of claim 2,
In the first precursor solution manufacturing step (S100),
The second precursor, InP / ZnS core-shell quantum dot is any one selected from the group consisting of trioctylphosphine oxide, hexylphosphonic acid, trioctylphosphine, Tris (trimethylsilyl) phosphine, diphenylpropylphosphine, tributylphosphine, triphenylphosphite, tetradecylphosphonic acid.
The method of claim 3, wherein
In the first precursor solution manufacturing step (S100),
The third precursor is sulfur in the form of powder (Sulfur) InP / ZnS core-shell quantum dot manufacturing method.
The method of claim 4, wherein
In the first precursor solution manufacturing step (S100),
The first solvent is any one selected from the group consisting of Oleylamine, octadecylamine, hexadecylamine, dodecylamine, oleic acid, 1-octadecene, 1-hexadecene, 1-eicosene, eicosane, octadecane, hexadecane, tetradecane, squalene, dodecanethiol InP / ZnS core-shell quantum dot manufacturing method.
The method of claim 1,
In the first precursor solution manufacturing step (S100),
The first precursor solution is heated to a temperature in the range of 140 ° C to 220 ° C InP / ZnS core-shell quantum dot manufacturing method.
The method of claim 1,
In the second precursor solution manufacturing step (S200),
The fourth precursor is a zinc undecylenate InP / ZnS core-shell quantum dot manufacturing method.
The method of claim 7, wherein
In the second precursor solution manufacturing step (S200),
The second solvent is any one selected from the group consisting of Oleylamine, octadecylamine, hexadecylamine, dodecylamine, oleic acid, 1-octadecene, 1-hexadecene, 1-eicosene, eicosane, octadecane, hexadecane, tetradecane, squalene, dodecanethiol InP / ZnS core-shell quantum dot manufacturing method.
The method of claim 1,
In the mixed solution heating step (S400),
The mixed first and second precursor solution is heated to a temperature of 280 ° C InP / ZnS core-shell quantum dot manufacturing method.
An InP / ZnS core-shell quantum dot prepared by the method of manufacturing an InP / ZnS core-shell quantum dot according to any one of claims 1 to 9.

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