Preparation of III-V semiconductor nanocrystals

• US 5,505,928 A
• Filed: 04/21/1994
• Issued: 04/09/1996
• Est. Priority Date: 11/22/1991
• Status: Expired due to Term

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Olshavsky, Michael A., Alivisatos, A. Paul
• Primary Examiner(s): Straub, Gary P.
• Application Number:
  US08/231,345
• Time in Patent Office: 719 Days
• Field of Search: 423/299, 423/290, 423/289, 420/528, 420/555, 420/576, 420/579
• US Class Current: 423/299
• CPC Class Codes: C01B 25/087 of gallium or indium
• CPC Class Codes: C01B 25/088 containing plural metal
• CPC Class Codes: C22C 1/047 comprising intermetallic compounds C22C1/0441 takes precedence
• CPC Class Codes: Y10S 977/815 Group III-V based compounds, e.g. AlaGabIncNxPyAsz
• CPC Class Codes: Y10S 977/826 Nonstoichiometric semiconductor compounds, e.g. IIIxVy; x does not equal y

Abstract

Nanometer-scale crystals of III-V semiconductors are disclosed, They are prepared by reacting a group III metal source with a group V anion source in a liquid phase at elevated temperature in the presence of a crystallite growth terminator such as pyridine or quinoline.

Claims

1. Particles of III-V semiconductor, said particles being crystalline, being soluble in quinoline or pyridine, and being sized such that at least about 50% are between 1 nanometer and 6 nanometers across.

2. The particles of claim 1 wherein the III-V semiconductor is GaAs.

3. The particles of claim 1 wherein the III-V semiconductor is GaP.

4. The particles of claim 1 wherein the III-V semiconductor is GaAs--P.

5. The particles of claim 1 wherein the III-V semiconductor is GaSb.

6. The particles of claim 1 wherein the III-V semiconductor is InAs.

7. The particles of claim 1 wherein the III-V semiconductor is InP.

8. The particles of claim 1 wherein the III-V semiconductor is InSb.

9. The particles of claim 1 wherein the III-V semiconductor is AlAs.

10. The particles of claim 1 wherein the III-V semiconductor is AlP.

11. The particles of claim 1 wherein the III-V semiconductor is AlSb.

12. A process for forming particles of a III-V semiconductor comprising

a) reacting, in a nonwater reaction medium comprising a nitrogen-containing aromatic heterocyclic material, a reaction medium-soluble group III metal source with a reaction medium-soluble group V nonmetal source at a temperature above 100°

,

b) removing the reaction medium thereby forming a reaction product comprising particles of III-V semiconductor, and

c) recovering the particles.

13. The process of claim 12 wherein the nitrogen-containing aromatic heterocyclic material is a liquid.

14. The process of claim 13 wherein the nitrogen-containing aromatic heterocyclic liquid material is quinoline.

15. The process of claim 13 wherein the nitrogen-containing aromatic heterocyclic liquid material is pyridine.

16. The process of claim 12 wherein the group III metal source is a group III metal salt or alkyl.

17. The process of claim 16 wherein the group III metal is gallium.

18. The process of claim 17 wherein the gallium source is a gallium III halide.

19. The process of claim 18 wherein the gallium III halide is GaCl₃.

20. The process of claim 17 wherein the nitrogen-containing aromatic heterocyclic material is a liquid.

21. The process of claim 20 wherein the nitrogen-containing aromatic heterocyclic liquid material is quinoline.

22. The process of claim 12 wherein the group V nonmetal source is selected from the group consisting of arsine, phosphine, stibine, trialkylarsine, trialkyphosphine, trialkylstibine, tris(tri-C₁ C₆ alkylsylyl) arsine, tris(tri-C₁ -C₆ alkylsilyl phosphine and tris(tri-C₁ -C₆ alkylsilyl) stibine.

23. The process of claim 12 wherein the group V nonmetal source is tris(tri-C₁ -C₆ alkyl-silyl)arsine.

24. The process of claim 23 wherein the group V nonmetal source is tris(trimethylsilyl)arsine.

25. A process for preparing particles of gallium arsenide comprising the steps of

(a) reacting gallium chloride with tri(trimethylsilyl)arsine in an about 1:

1 molar ratio in a quinoline reaction phase at a temperature of from 200°

-300°

C. thereby forming a GaAs-containing reaction product, and

(b) removing the quinoline from the reaction product thereby yielding GaAs particles as a dry red powder.