Semiconductor nanoparticles and method of producing semiconductor nanoparticles

Patent metadata

Field	Value
Publication number	US-2022017819-A1
Application number	US-202117449255-A
Country	US
Kind code	A1
Filing date	Sep 28, 2021
Priority date	Mar 18, 2016
Publication date	Jan 20, 2022
Grant date	—

Abstract

A semiconductor nanoparticle includes a core and a shell covering a surface of the core. The shell has a larger bandgap energy than the core and is in heterojunction with the core. The semiconductor nanoparticle emits light when irradiated with light. The core is made of a semiconductor that contains M1, M2, and Z. M1 is at least one element selected from the group consisting of Ag, Cu, and Au. M2 is at least one element selected from the group consisting of Al, Ga, In and Tl. Z is at least one element selected from the group consisting of S, Se, and Te. The shell is made of a semiconductor that consists essentially of a Group 13 element and a Group 16 element.

First claim

What is claimed is:

1 . A semiconductor nanoparticle comprising:
a core comprising a semiconductor being adapted to emit photoluminescence upon being irradiated with light; and a shell covering a surface of the core and having a bandgap energy larger than a bandgap energy of the core, the shell being in heterojunction with the core, wherein the semiconductor contains M 1 , M 2 , and Z, wherein M 1 is at least one element selected from the group consisting of Ag, Cu, and Au, and comprises at least Ag,
M 2 is at least one element selected from the group consisting of Al, Ga, In, and Tl, and comprises at least In,
and Z is at least one element selected from the group consisting of S, Se, and Te, and comprises at least S,
wherein the shell comprises a semiconductor containing a Group 13 element and a Group 16 element, and wherein a photoluminescence lifetime of the semiconductor nanoparticles is 200 ns or less.

2 . The semiconductor nanoparticle according to claim 1 , wherein the shell contains In as the Group 13 element.

3 . The semiconductor nanoparticle according to claim 2 , wherein the shell contains S as the Group 16 element.

4 . The semiconductor nanoparticle according to claim 1 , wherein the shell contains Ga as the Group 13 element.

5 . The semiconductor nanoparticle according to claim 4 , wherein the shell contains S as the Group 16 element.

6 . The semiconductor nanoparticle according to claim 1 , wherein the core contains Ag as M 1 , In as M 2 , and S as Z.

7 . The semiconductor nanoparticle according to claim 1 , wherein the core further contains M 3 , wherein M 3 is at least one element selected from the group consisting of Zn and Cd.

8 . The semiconductor nanoparticle according to claim 1 , wherein a photoluminescence spectrum of the semiconductor nanoparticle has a peak with a full width at half maximum of 50 nm or less.

9 . The semiconductor nanoparticle according to claim 1 , wherein the semiconductor nanoparticle has an average particle size of from 1 nm to 20 nm.

10 . The semiconductor nanoparticle according to claim 1 , wherein the core has an average particle size of from 2 nm to 10 nm.

11 . The semiconductor nanoparticle according to claim 1 , wherein a thickness of the shell is in a range of 0.1 nm to 20 nm.

12 . The semiconductor nanoparticle according to claim 1 , wherein an excitation spectrum or an absorption spectrum of the semiconductor nanoparticles exhibits an exciton peak.

13 . A light-emitting device comprising a light conversion member and a semiconductor light-emitting element, wherein the light conversion member contains a plurality of the semiconductor nanoparticle according to claim 1 .

14 . The light-emitting device according to claim 13 , wherein the semiconductor light-emitting element is a light-emitting diode chip.

15 . A method of producing semiconductor nanoparticles, comprising:
providing a dispersion by dispersing primary semiconductor nanoparticles into a solvent, each of the primary semiconductor nanoparticles comprising a semiconductor that contains M 1 , M 2 , and Z, wherein M 1 is at least one element selected from the group consisting of Ag, Cu, and Au, and comprises at least Ag, M 2 is at least one element selected from the group consisting of Al, Ga, In, and Tl, and comprises at least In, and Z is at least one element selected from the group consisting of S, Se, and Te, and comprises at least S; and adding, to the dispersion, a compound containing a Group 13 element, and an elemental substance of a Group 16 element or a compound containing the Group 16 element to form a semiconductor layer comprising the Group 13 element and the Group 16 element on a surface of each of the primary semiconductor nanoparticles, wherein a photoluminescence lifetime of the semiconductor nanoparticles is 200 ns or less.

16 . The method of producing semiconductor nanoparticles according to claim 15 , wherein the compound containing the Group 16 element is dibenzyldisulfide.

17 . The method of producing semiconductor nanoparticles according to claim 15 , further comprising, after the adding:
heating the dispersion at a predetermined rate up to a peak temperature that is in a range of 200° C. to 290° C., and holding the dispersion at the peak temperature for a predetermined period of time.

18 . The method of producing semiconductor nanoparticles according to claim 17 , wherein the elemental substance of the Group 16 element is an elemental sulfur, and the predetermined period of time for holding the dispersion at the peak temperature is not less than 40 minutes and not more than 60 minutes.

19 . The method of producing semiconductor nanoparticles according to claim 15 , wherein the dispersion contains n-tetradecylamine.

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
• Niki Kenta

Classifications

• H10H20/8512

  Wavelength conversion materials · CPC title

• Y10S977/95

  Electromagnetic energy · CPC title

• Y10S977/774

  Exhibiting three-dimensional carrier confinement, e.g. quantum dots · CPC title

• G02F1/133614

  using photoluminescence, e.g. phosphors illuminated by UV or blue light · CPC title

• G02F1/133617

  Illumination with ultraviolet light; Luminescent elements or materials associated to the cell · CPC title