Cadmium-free quantum dot nanoparticles

Patent metadata

Field	Value
Publication number	US-10483440-B2
Application number	US-201715725768-A
Country	US
Kind code	B2
Filing date	Oct 5, 2017
Priority date	Jan 6, 2014
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

Quantum dot semiconductor nanoparticle compositions that incorporate ions such as zinc, aluminum, calcium, or magnesium into the quantum dot core have been found to be more stable to Ostwald ripening. A core-shell quantum dot may have a core of a semiconductor material that includes indium, magnesium, and phosphorus ions. Ions such as zinc, calcium, and/or aluminum may be included in addition to, or in place of, magnesium. The core may further include other ions, such as selenium, and/or sulfur. The core may be coated with one (or more) shells of semiconductor material. Example shell semiconductor materials include semiconductors containing zinc, sulfur, selenium, iron and/or oxygen ions.

First claim

What is claimed is:

1. A quantum dot nanoparticle comprising:
a core having an etched surface and comprising indium, phosphorus, magnesium, zinc, and sulfur;
a first shell disposed on the etched surface of the core; and
a second shell disposed on the first shell,
wherein the quantum dot nanoparticle emits light in the green region of the visible spectrum.

2. The quantum dot nanoparticle of claim 1 , wherein the first shell is ZnS.

3. The quantum dot nanoparticle of claim 1 , wherein there is a gradient of materials at a boundary between the core and the first shell.

4. The quantum dot nanoparticle of claim 1 , wherein there is a gradient of materials at the boundary between the first shell and the second shell.

5. The quantum dot nanoparticle of claim 1 , further comprising at least one capping ligand.

6. The quantum dot nanoparticle of claim 1 , wherein the second shell is ZnO.

7. The quantum dot nanoparticle of claim 1 , wherein the quantum dot nanoparticle exhibits a quantum yield of at least 74%.

8. The quantum dot nanoparticle of claim 1 , wherein the emitted light has an emission maximum of 523 nm with a full-width at half-maximum (FWHM) of 57 nm.

Assignees

• Nanoco Technologies Ltd

Inventors

• Glarvey Paul Anthony
• Harris James
• Daniels Steven
• Pickett Nigel
• Narayanaswamy Arun

Classifications

• B22F1/054

  Nanosized particles · CPC title

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title

• C09K11/70

  containing phosphorus · CPC title

• C09K11/623

  with zinc or cadmium · CPC title

• C09C3/063

  Coating · CPC title