# US 2025/0084306 A1 · Quantum dot and method for preparing the quantum dot

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- Number: US 2025/0084306 A1
- Document ID: US20250084306A1
- Status: Published application
- Kind: A1
- Application number: 18/774,800
- Filed: 2024-07-16
- Published: 2025-03-13
- Earliest claimed: 2023-09-11
- Assignees: Samsung Display Co., Ltd.
- Applicants: Samsung Display Co., Ltd.
- Inventors: JUNEHYUK JUNG; SUNGJAE KIM; Youngsik KIM; Bitna YOON; DONGHEE LEE; TAEKJOON LEE
- Web page: https://patentgrep.com/patent/US20250084306A1

## CPC

- C09K 11/621: {Chalcogenides}
- C09K 11/02: Use of particular materials as binders, particle coatings or suspension media therefor
- C09K 11/565: {with zinc cadmium}
- C09K 11/623: {with zinc or cadmium}
- C09K 11/883: {with zinc or cadmium}
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

A method for preparing a quantum dot and a quantum dot are provided. The method for preparing a quantum dot includes supplying a first mixture including a first precursor containing gallium oleate, a second precursor containing indium oleate, and a third precursor containing a sulfur atom, forming a second mixture by adding a first solvent to the first mixture, and forming a fourth mixture including a core containing a copper atom, an indium atom, a gallium atom, and a sulfur atom by adding a third mixture containing copper to the second mixture.

## Claims

### Claim 1

A method for preparing a quantum dot, the method comprising:
supplying a first mixture comprising
a first precursor comprising gallium oleate,
a second precursor comprising indium oleate, and
a third precursor comprising a sulfur atom;
forming a second mixture by adding a first solvent to the first mixture; and
forming a fourth mixture comprising a core comprising a copper atom, an indium atom, a gallium atom, and a sulfur atom by adding a third mixture comprising copper to the second mixture.

### Claim 2 (depends on 1)

The method of claim 1, wherein the core has a diameter of about 3 nm to about 6 nm.

### Claim 3 (depends on 1)

The method of claim 1, wherein the first solvent comprises at least one selected from among 1-octadecene and trioctylamine.

### Claim 4 (depends on 1)

The method of claim 1, further comprising reacting the fourth mixture at a first temperature for about 5 minutes to about 15 minutes,
wherein the first temperature is about 250° C. to about 350° C.

### Claim 5 (depends on 1)

The method of claim 1, wherein, in the second mixture, a number of moles of gallium atoms is greater than a number of moles of indium atoms.

### Claim 6 (depends on 1)

The method of claim 1, further comprising forming a first shell around the core by reacting the core with a fourth precursor containing zinc oleate and a fifth precursor containing a sulfur atom.

### Claim 7 (depends on 6)

The method of claim 6, wherein:
a mass of gallium atoms is about 5 wt % to about 50 wt % with respect to a total mass of 100 wt % the quantum dot; and
a ratio of the mass of gallium atoms with respect to the mass of the quantum dot is greater than a ratio of a mass of indium atoms with respect to the mass of the quantum dot in the quantum dot.

### Claim 8 (depends on 6)

The method of claim 6, wherein:
the first solvent comprises 1-octadecene and trioctylamine; and
the method further comprises degassing trioctylamine at 120° C. before the forming of the first shell.

### Claim 9 (depends on 6)

The method of claim 6, wherein:
the forming of the first shell is performed at a second temperature for about 15 minutes to about 25 minutes; and
the second temperature is about 280° C. to about 350° C.

### Claim 10 (depends on 6)

The method of claim 6, wherein a molar ratio of the fourth precursor to the fifth precursor is about 1:1.

### Claim 11 (depends on 6)

The method of claim 6, wherein, in the forming of the first shell, the fourth precursor and the fifth precursor are each independently provided in an amount of about 0.4 mmol to about 1.6 mmol.

### Claim 12 (depends on 6)

The method of claim 6, wherein the first shell has a thickness of about 0.5 nm to about 3 nm.

### Claim 13 (depends on 6)

The method of claim 6, further comprising forming a second shell around the first shell by adding a first element precursor and a second element precursor to a first particle comprising the core and the first shell.

### Claim 14 (depends on 13)

The method of claim 13, wherein the second shell comprises at least one selected from among ZnSe, ZnS, ZnTe, ZnO, ZnMg, ZnMgSe, ZnMgS, ZnMgAl, GaSe, GaTe, GaP, GaAs, GaSb, InAs, InSb, AlP, AlAs, AlSb, MnS, MnSe, MgS, and MgSe.

### Claim 15 (depends on 13)

The method of claim 13, wherein the second shell has a thickness of about 0.5 nm to about 3 nm.

### Claim 16 (depends on 13)

The method of claim 13, wherein a thickness of the second shell is greater than a thickness of the first shell.

### Claim 17

A quantum dot comprising:
a core comprising a copper atom, an indium atom, a gallium atom, and a sulfur atom, and
a first shell around the core and comprising a zinc atom, and a sulfur atom,
wherein the core has a diameter of about 3 nm to about 6 nm.

### Claim 18 (depends on 17)

The quantum dot of claim 17, wherein in the quantum dot:
a mass of gallium atoms is about 5 wt % to about 50 wt % with respect to a total mass of 100 wt % of the quantum dot; and
a ratio of the mass of gallium atoms with respect to the mass of the quantum dot is greater than a ratio of a mass of indium atoms with respect to the mass of the quantum dot.

### Claim 19 (depends on 17)

The quantum dot of claim 17, further comprising:
a second shell around the first shell and comprising at least one selected from among ZnSe, ZnS, ZnTe, ZnO, ZnMg, ZnMgSe, ZnMgS, ZnMgAl, GaSe, GaTe, GaP, GaAs, GaSb, InAs, InSb, AlP, AlAs, AlSb, MnS, MnSe, MgS, and MgSe.

### Claim 20 (depends on 19)

The quantum dot of claim 19, wherein a thickness of the second shell is greater than a thickness of the first shell.