Quantum dot and method for producing the same

Patent metadata

Field	Value
Publication number	US-12545838-B2
Application number	US-202418601397-A
Country	US
Kind code	B2
Filing date	Mar 11, 2024
Priority date	Sep 20, 2019
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

An object is to provide a quantum dot that has a narrow fluorescence half-width and a high fluorescence quantum yield, and emits blue fluorescence. A quantum dot ( 5 ) according to the present invention includes at least Zn and Se and does not include Cd, and has a particle diameter of 5 nm or more and 20 nm or less. In addition, the quantum dot ( 5 ) according to the present invention includes at least Zn and Se and does not include Cd, and has a fluorescence quantum yield of 58 or more and a fluorescence half-width of 25 nm or less. In the present invention, the fluorescence lifetime can be made 50 ns or less.

First claim

The invention claimed is:

1 . A quantum dot having a core-shell structure comprising:
a core formed from Zn, Se, and Te; and a shell that covers the core and is formed from Zn and S, wherein a particle diameter of the quantum dot is 5 nm or more and 20 nm or less, and wherein a nonzero residual amount of Cu is 100 ppm or less relative to Zn.

2 . The quantum dot according to claim 1 , wherein a fluorescence lifetime of the quantum dot is 50 ns or less.

3 . The quantum dot according to claim 1 , wherein the quantum dot has a fluorescence wavelength of 410 nm or more and 490 nm or less.

4 . The quantum dot according to claim 1 , wherein the quantum dot has a surface covered with a ligand.

5 . The quantum dot according to claim 4 , wherein the ligand is at least one selected from aliphatic amine-based ligands, phosphine-based ligands, and aliphatic carboxylic acid-based ligands.

6 . A manufacturing method for a quantum dot, comprising:
synthesizing a copper chalcogenide precursor from an organic copper compound or an inorganic copper compound, and an organic chalcogen compound; forming a core from Zn, Se, and Te by using the copper chalcogenide precursor; and covering the core with a shell that is formed from Zn and S.

7 . The manufacturing method for a quantum dot according to claim 6 , wherein Zn and Cu of the copper chalcogenide precursor are metal-exchanged.

8 . The manufacturing method for a quantum dot according to claim 7 , wherein the metal exchange reaction is performed at 150° C. or more and 300° C. or less.

9 . The manufacturing method for a quantum dot according to claim 6 , wherein the copper chalcogenide precursor is synthesized at a reaction temperature of 140° C. or more and 250° C. or less.

Assignees

• Ns Mat Inc
• Toppan Inc

Inventors

• Nikata Soichiro
• Ogura Yuko
• Takasaki Mikihiro
• Takamizuma Yuka

Classifications

• C01P2004/80

  Particles consisting of a mixture of two or more inorganic phases · CPC title

• C09K11/02

  Use of particular materials as binders, particle coatings or suspension media therefor · CPC title

• C09K11/88

  containing selenium, tellurium or unspecified chalcogen elements · CPC title

• C01P2006/60

  Optical properties, e.g. expressed in CIELAB-values · CPC title

• C01P2004/64

  Nanometer sized, i.e. from 1-100 nanometer · CPC title