Semiconductor nanoparticles, production method thereof, and light-emitting device

Patent metadata

Field	Value
Publication number	US-12074253-B2
Application number	US-202218053057-A
Country	US
Kind code	B2
Filing date	Nov 7, 2022
Priority date	Feb 15, 2018
Publication date	Aug 27, 2024
Grant date	Aug 27, 2024

Abstract

Provided is a method of producing semiconductor nanoparticles that exhibit a band-edge emission, and are superior in quantum yield. The method includes raising the temperature of a first mixture containing a silver (Ag) salt, a salt containing at least one of indium (In) and gallium (Ga), a solid compound that serves as a supply source of sulfur (S), and an organic solvent to a temperature in a range of from 125 □C to 175 □C, and heat-treating, subsequent to the raising of the temperature, the first mixture at a temperature in a range of from 125 □C to 175 □C for three seconds or more to obtain a solution containing semiconductor nanoparticles, and decreasing the temperature of the solution containing semiconductor nanoparticles. The solid compound that serves as a supply source of S contains thiourea.

First claim

What is claimed is:

1. Core-shell semiconductor nanoparticles, each comprising:
a core; and
a shell disposed on a surface of the core, and
emitting light when irradiated with light,

wherein the core contains Ag, at least one of In and Ga, and S,
the shell contains a semiconductor essentially composed of a Group 13 element and a Group 16 element, and having a greater band-gap energy than the core,
the core-shell semiconductor nanoparticles have an essentially tetragonal crystal structure, and an emission peak with a half bandwidth of 70 nm or less, and
a compound containing a Group 15 element disposed on a surface of the shell, and the Group 15 element contains at least P with a negative oxidation number.

2. The core-shell semiconductor nanoparticles according to claim 1 , having an average particle diameter of from 1.5 nm to 7.5 nm.

3. The core-shell semiconductor nanoparticles according to claim 1 , wherein the shell contains Ga as the Group 13 element.

4. The core-shell semiconductor nanoparticles according to claim 1 , wherein the shell contains S as the Group 16 element.

5. The core-shell semiconductor nanoparticles according to claim 1 , having an emission lifetime of 200 ns or less.

6. The core-shell semiconductor nanoparticles according to claim 1 , having an excitation spectrum or an absorption spectrum with an exciton peak.

7. The core-shell semiconductor nanoparticles according to claim 1 , having an emission spectrum with a band-edge emission component with a purity of 40% or more.

8. The core-shell semiconductor nanoparticles according to claim 1 , having an emission peak wavelength in a range of from 500 nm to 600 nm.

9. The core-shell semiconductor nanoparticles according to claim 1 , exhibiting a band-edge emission with a quantum yield of 40% or more.

10. A light-emitting device, comprising:
a light conversion member including the core-shell semiconductor nanoparticles according to claim 7 ; and
a semiconductor light-emitting element.

11. The light-emitting device according to claim 10 , wherein the semiconductor light-emitting element is an LED chip.

Assignees

• Univ Osaka
• National Univ Corporation Tokai National Higher Education And Research System
• Nichia Corp

Inventors

• Kuwabata Susumu
• Uematsu Taro
• Wajima Kazutaka
• Torimoto Tsukasa
• Kameyama Tatsuya
• Oyamatsu Daisuke

Classifications

• H10H20/851

  Wavelength conversion means · CPC title

• H10H20/01

  Manufacture or treatment · CPC title

• H10H20/822 Primary

  Materials of the light-emitting regions · CPC title

• H10H20/0361

  of wavelength conversion means · CPC title

• H10H20/8514

  characterised by their shape, e.g. plate or foil · CPC title