Quantum dots and devices including the same

Patent metadata

Field	Value
Publication number	US-11624027-B2
Application number	US-202117366429-A
Country	US
Kind code	B2
Filing date	Jul 2, 2021
Priority date	Jul 3, 2020
Publication date	Apr 11, 2023
Grant date	Apr 11, 2023

Abstract

A quantum dot according to an embodiment includes a core including a first semiconductor nanocrystal including zinc, selenium, and tellurium and a semiconductor nanocrystal shell on the core, the semiconductor nanocrystal shell including a zinc chalcogenide, wherein the quantum dot does not include cadmium, the zinc chalcogenide includes zinc and selenium, the quantum dot further includes gallium and a primary amine having 5 or more carbon atoms, and the quantum dot is configured to emit light having a maximum emission peak in a range of greater than about 450 nanometers (nm) and less than or equal to about 480 nm by excitation light. A method of producing the quantum dot and an electronic device including the same are also disclosed.

First claim

What is claimed is:

1. A quantum dot, comprising:
a core comprising a first semiconductor nanocrystal comprising zinc, selenium, and tellurium, and
a semiconductor nanocrystal shell on the core, the semiconductor nanocrystal shell comprising a zinc chalcogenide,
wherein the quantum dot does not comprise cadmium,
the zinc chalcogenide comprises zinc and selenium,
the quantum dot further comprises gallium and a primary amine having 5 or more carbon atoms, and
the quantum dot is configured to emit light having a maximum emission peak in a range of greater than about 450 nanometers and less than or equal to about 480 nanometers by excitation light.

2. The quantum dot of claim 1 , wherein the maximum emission peak has a full width at half maximum of less than about 33 nanometers.

3. The quantum dot of claim 1 , wherein a maximum emission peak wavelength of the quantum dot is greater than or equal to about 453 nanometers.

4. The quantum dot of claim 1 , wherein the first semiconductor nanocrystal or the quantum dot does not comprise a Group III-V compound.

5. The quantum dot of claim 1 , wherein in the quantum dot, a mole ratio of tellurium to selenium is greater than or equal to about 0.0053:1.

6. The quantum dot of claim 1 , wherein in the quantum dot, a mole ratio of gallium to zinc is greater than or equal to about 0.1:1.

7. The quantum dot of claim 1 , wherein
the zinc chalcogenide further comprises sulfur, and
in the quantum dot, a mole ratio of selenium to zinc is greater than or equal to about 0.46:1 and a mole ratio of sulfur to selenium is less than or equal to about 0.93:1.

8. The quantum dot of claim 1 , wherein the quantum dot has an average decay time for the excitation light of less than or equal to about 50 nanoseconds, as determined by a time-resolved photoluminescence analysis.

9. The quantum dot of claim 1 , wherein the quantum dot has a tellurium relative emission of less than or equal to about 50%, as determined by a time-resolved photoluminescence analysis.

10. The quantum dot of claim 1 , wherein in a gas chromatography mass spectrometry, the quantum dot exhibits a peak of a primary carboxylic acid compound having 10 or more carbon atoms and a peak of the primary amine, and a peak intensity ratio of the peak of the primary amine to the peak of the primary carboxylic acid compound is greater than or equal to about 0.5:1.

11. The quantum dot of claim 10 , wherein a peak intensity ratio of the peak of the primary amine to the peak of the primary carboxylic acid compound is greater than or equal to about 1:1.

12. The quantum dot of claim 1 , wherein the quantum dot has a quantum efficiency of greater than or equal to about 75%.

13. The quantum dot of claim 1 , wherein the quantum dot has a 5% weight loss temperature of less than about 400° C., as determined by a thermogravimetric analysis.

14. The quantum dot of claim 1 , wherein in a thermogravimetric analysis, the quantum dot has an organic material content of less than or equal to about 12 weight percent, as determined by a thermogravimetric analysis.

15. A method of producing the quantum dot of claim 1 , comprising
adding a quantum dot comprising
a core comprising a first semiconductor nanocrystal comprising zinc, selenium, and tellurium, and
a semiconductor nanocrystal shell on the core, the semiconductor nanocrystal shell comprising a zinc chalcogenide to an organic solvent to prepare a mixture; and

adding a gallium treatment agent comprising a gallium compound and a primary amine, and optionally a sulfur treatment agent, to the mixture, and
heating the mixture to a temperature of greater than or equal to about 180° C.

16. The method of claim 15 , wherein the gallium compound comprises alkyl gallium and the gallium treatment agent does not comprise oxygen.

17. The method of claim 15 , comprising adding the sulfur treatment agent to the mixture, wherein the sulfur treatment agent comprises a trialkylsilyl sulfide compound.

18. A quantum dot comprising:
zinc,
selenium,
tellurium, and
sulfur
and not comprising cadmium,
wherein the quantum dot further comprises gallium and a primary amine having 5 or more carbon atoms,
the quantum dot is configured to emit light having a maximum emission peak in a range of greater than or equal to about 453 nanometers and less than or equal to about 480 nanometers by excitation light, and
in the quantum dot, a mole ratio of gallium to zinc is greater than or equal to about 0.1:1 and less than about 1:1.

19. The quantum dot of claim 18 , wherein the quantum dot has a full width at half maximum of less than or equal to about 30 nanometers and a quantum efficiency of greater than or equal to 80%.

20. The quantum dot of claim 18 , wherein the primary amine comprises an alkenyl group having 10 or more carbon atoms.

21. The quantum dot of claim 18 , wherein the quantum dot does not comprise a semiconductor nanocrystal of a Group III-V compound.

22. An electroluminescent device comprising
a first electrode and a second electrode facing each other; and
a quantum dot emission layer between the first electrode and the second electrode, the quantum dot emission layer comprising a plurality of quantum dots,
wherein the plurality of quantum dots comprise the quantum dot of claim 1 .

23. A quantum dot, comprising:
a core comprising a first semiconductor nanocrystal comprising zinc, selenium, and tellurium;
a semiconductor nanocrystal shell on the core, the semiconductor nanocrystal shell comprising zinc and selenium; and
a ligand comprising gallium and a primary amine having 5 or more carbon atoms on a surface of the quantum dot,
wherein the quantum dot does not comprise cadmium,
the quantum dot is configured to emit light having a maximum emission peak in a range of greater than about 450 nanometers and less than or equal to about 480 nanometers by excitation light, and
the maximum emission peak has a full width at half maximum of less than about 33 nanometers.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kim Sung Woo
• Jang Eun Joo
• Jang Hyo Sook
• Kim Hwea Yoon
• Won Yuho

Classifications

• C01P2004/64

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

• C09K11/02 Primary

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

• B82Y20/00

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

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C09K11/54

  containing zinc or cadmium · CPC title