Quantum dot and method for producing the same

Patent metadata

Field	Value
Publication number	US-12577464-B2
Application number	US-202318383091-A
Country	US
Kind code	B2
Filing date	Oct 24, 2023
Priority date	Aug 23, 2019
Publication date	Mar 17, 2026
Grant date	Mar 17, 2026

Abstract

To provide Cd-free chalcopyrite-based quantum dots with a narrow fluorescence FWHM and a high fluorescence quantum yield. The quantum dots of the present invention contain AgIn x Ga 1−x S y Se 1−y or ZnAgIn x Ga 1−x S y Se 1−y (where 0≤x<1 and 0≤y≤1) and exhibit fluorescence properties including a fluorescence FWHM of less than or equal to 45 nm and a fluorescence quantum yield of greater than or equal to 35% in the green wavelength range to the red wavelength range.

First claim

The invention claimed is:

1 . A method for synthesizing quantum dots, comprising:
synthesizing
a composition including
an organic silver compound,
an organic gallium compound, and
sulfur or selenium, or

a composition including
an organic silver compound,
an organic indium compound,
an organic gallium compound,
and sulfur or selenium, and

thereafter, adding an organic zinc compound or an inorganic zinc compound, each quantum dot containing ZnAgIn x Ga 1−x S y Se 1−y (wherein 0≤x<1 and 0≤y≤1),
wherein the quantum dot contains at least silver (Ag), gallium (Ga), and selenium (Se), or contains at least silver (Ag), gallium (Ga), and sulfur(S), and does not contain cadmium (Cd).

2 . The method for synthesizing the quantum dots according to claim 1 , wherein:
the synthesizing the quantum dots includes forming particles in an initial stage of a reaction and adding a predetermined element later, and the particles do not contain In in the initial stage of the reaction.

3 . The method for synthesizing the quantum dots according to claim 2 , wherein Zn is not added in the initial stage of the reaction and is added later.

4 . The method for synthesizing the quantum dots according to claim 1 , wherein thiuram, disulfide, S-ODE obtained by dissolving S in octadecene, or S-OLAm/DDT obtained by dissolving S in oleylamine and dodecanethiol is used as a S source.

5 . The method for synthesizing the quantum dots according to claim 1 , wherein Se-OLAm/DDT obtained by dissolving Se in oleylamine and dodecanethiol is used as a Se source.

6 . The method for synthesizing the quantum dots according to claim 1 , wherein gallium acetylacetonate (Ga(acac)3) or gallium chloride (GaCl3) is used as a Ga source.

7 . The method for synthesizing the quantum dots according to claim 1 ,
further comprising adding TOP to a reaction solution obtained by
mixing an Ag source, a Ga source and a S source, or
mixing an Ag source, a Ga source, and a Se source, or
further comprising performing a dispersion process using TOP for the reaction solution.

8 . The method for synthesizing the quantum dots according to claim 1 , further comprising centrifuging a reaction solution synthesized by
mixing an Ag source, a Ga source, and a S source, or mixing an Ag source, a Ga source, and a Se source.

9 . The method for synthesizing the quantum dots according to a claim 8 , wherein the centrifugation is performed by adding as a solvent toluene, methanol, ethanol, or acetone to the reaction solution synthesized by
mixing the Ag source, the Ga source, and the S source, or mixing the Ag source, the Ga source, and the Se source.

Assignees

• Ns Mat Inc
• Toppan Inc

Inventors

• Nikata Soichiro
• Michiwaki Yoko
• Hieda Tomoaki
• Ogura Yuko
• Mishima Akio
• Kalousek Vit

Classifications

• C01P2006/60

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

• C01P2004/64

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

• C01G15/006

  Compounds containing gallium, indium or thallium, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• B82Y20/00

  Nanooptics, e.g. quantum optics or photonic crystals · CPC title