Group III-V/Zinc chalcogenide alloyed semiconductor quantum dots

Patent metadata

Field	Value
Publication number	US-10351767-B2
Application number	US-201615275659-A
Country	US
Kind code	B2
Filing date	Sep 26, 2016
Priority date	Mar 15, 2013
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

A scalable method for the manufacture of narrow, bright, monodisperse, photo-luminescent quantum dots prepared in the presence of a Group II-VI molecular seeding cluster fabricated in situ from a zinc salt and a thiol or selenol compound. Exemplary quantum dots have a core containing indium, phosphorus, zinc and either sulfur or selenium.

First claim

What is claimed is:

1. A method of forming a quantum dot (QD), the method comprising:
forming a zinc chalcogenide molecular cluster compound in situ from a zinc precursor and a chalcogen precursor; and
growing a semiconductor core in the presence of the zinc chalcogenide molecular cluster compound from a group III precursor and a group V precursor by
heating a mixture comprising the group III precursor, the group V precursor, the zinc precursor and the chalcogen precursor at a first temperature sufficient to dissolve the group III precursor, the group V precursor, the zinc precursor and the chalcogen precursor, and
heating the mixture to a second temperature sufficient to initiate growth of a QD core, wherein

the zinc precursor is zinc acetate or zinc stearate,
the chalcogen precursor is 1-dodecanethiol, thiophenol or 1-octane selenol,
the group III precursor comprises a phosphine, an alkyl, an aryl, an acetate, an acetylacetonate, a carbonate, a beta-diketonate, an oxide, or a nitrate.

2. A method as recited in claim 1 , wherein the semiconductor core is formed on the molecular cluster compound.

3. A method as recited in claim 1 , wherein the first temperature is between 25° C. and 100° C., and the second temperature is between 100° C. and 350° C.

4. A method as recited in claim 3 , further comprising maintaining the second temperature for at least 24 hours.

5. A method as recited in claim 1 , wherein the zinc precursor and the chalcogen precursor provide a zinc:chalcogen molar ratio between about 10:4 and about 10:16.

6. A method as recited in claim 5 , wherein the zinc and chalcogen increase the band gap of the QD.

7. A method as recited in claim 2 , wherein the group III precursor is indium myristate and the group V precursor is tris(trimethylsilyl)phosphine.

8. A method as recited in claim 1 , wherein the group V precursor comprises a phosphide, phosphine, an arsenide, arsine, an alkyl, an aryl, an amine, hydrazine, dimethylhydrazine, ethyl azide, a carbonate, a beta-diketonate, an acetylacetonate, an oxide, or a nitrate.

9. A method of forming photo-luminescent InPZnS quantum dot (QD) cores comprising:
dissolving indium myristate, myristic acid, a zinc salt, tris(trimethylsilyl)phosphine, a pre-formed molecular cluster compound comprising zinc and sulfur, and an alkyl or aryl thiol in a solvent to form a mixture;
adding additional tris(trimethylsilyl)phosphine to the mixture;
raising the temperature of the mixture to a temperature sufficient to initiate growth of the QD cores; and
maintaining the mixture at the temperature for at least 24 hours, wherein
the zinc salt is zinc acetate or zinc stearate,
the alkyl or aryl thiol is 1-dodecanethiol or thiophenol, and
the pre-formed molecular cluster compound is formed in situ prior to formation of the mixture.

10. A method as recited in claim 9 , wherein the molar ratio of zinc salt to alkyl or aryl thiol is between about 10:4 and about 10:16.

11. A method as recited in claim 9 , wherein the pre-formed molecular cluster compound has the formula [Zn 10 S 4 (S(C 6 H 5 )) 16 ][NH(C 2 H 5 ) 3 ] 4 .

12. A method as recited in claim 9 , wherein the temperature to initiate growth of the QD cores is between 100° C. and 350° C.

13. A method of forming a quantum dot (QD), the method comprising:
forming a zinc chalcogenide molecular cluster compound in situ from a zinc precursor and a chalcogen precursor; and
growing a semiconductor core in the presence of the zinc chalcogenide molecular cluster compound from a group III precursor and a group V precursor by
heating a mixture comprising the group III precursor, the group V precursor, the zinc precursor and the chalcogen precursor at a first temperature sufficient to dissolve the group III precursor, the group V precursor, the zinc precursor and the chalcogen precursor, and
heating the mixture to a second temperature sufficient to initiate growth of a QD core, wherein

the zinc precursor is zinc acetate or zinc stearate,
the chalcogen precursor is 1-dodecanethiol, thiophenol or 1-octane selenol, and
the group V precursor comprises a phosphide, phosphine, an arsenide, arsine, an alkyl, an aryl, an amine, hydrazine, dimethylhydrazine, ethyl azide, a carbonate, a beta-diketonate, an acetylacetonate, an oxide, or a nitrate.

14. A method as recited in claim 13 , wherein the semiconductor core is formed on the molecular cluster compound.

15. A method as recited in claim 14 , wherein the group III precursor is indium myristate and the group V precursor is tris(trimethylsilyl)phosphine.

16. A method as recited in claim 13 , wherein the first temperature is between 25° C. and 100° C., and the second temperature is between 100° C. and 350° C.

17. A method as recited in claim 16 , further comprising maintaining the second temperature for at least 24 hours.

18. A method as recited in claim 13 , wherein the zinc precursor and the chalcogen precursor provide a zinc:chalcogen molar ratio between about 10:4 and about 10:16.

19. A method as recited in claim 18 , wherein the zinc and chalcogen increase the band gap of the QD.

20. A method as recited in claim 18 , wherein the group III precursor comprises a phosphine, an alkyl, an aryl, an acetate, an acetylacetonate, a carbonate, a beta-diketonate, an oxide, or a nitrate.

Assignees

• Nanoco Technologies Ltd

Inventors

• Daniels Steven
• Harris James
• Glarvey Paul
• Orchard Katherine
• Narayanaswamy Arun

Classifications

• C09K11/02

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

• B01J2/003

  followed by coating of the granules (to prevent the granules sticking together B01J2/30) · CPC title

• C09K11/703 Primary

  with zinc or cadmium · CPC title

• H01L33/06

  Electricity · mapped topic

• H10H20/812 Primary

  within the light-emitting regions, e.g. having quantum confinement structures · CPC title