Liquid precursor for deposition of indium selenide and method of preparing the same

• US 20120094431A1
• Filed: 08/16/2011
• Published: 04/19/2012
• Est. Priority Date: 08/16/2010
• Status: Active Grant

• Current Assignee: Alliance For Sustainable Energy LLC, HelioVolt Corporation
• Original Assignee: HelioVolt Corporation
• Inventors: Curtis, Calvin J., Miedaner, Alexander, Hersh, Peter A., Eldada, Louay, Stanbery, Billy J., Antonius Maria van Hest, Marinus Franciscus, Ginley, David S.
• Granted Patent: US 9,142,408 B2
• Time in Patent Office: Days
• US Class Current: 438/102
• CPC Class Codes: C23C 18/1204 inorganic material, e.g. non-oxide and non-metallic such as sulfides, nitrides based compounds
• CPC Class Codes: H01L 21/02568 Chalcogenide semiconducting materials not being oxides, e.g. ternary compounds
• CPC Class Codes: H01L 21/02628 using solutions
• CPC Class Codes: H01L 31/0322 comprising only AIBIIICVI chalcopyrite compounds, e.g. Cu In Se2, Cu Ga Se2, Cu In Ga Se2
• CPC Class Codes: H01L 31/20 such devices or parts thereof comprising amorphous semiconductor materials
• CPC Class Codes: Y02E 10/541 CuInSe2 material PV cells

Abstract

Liquid precursors containing indium and selenium suitable for deposition on a substrate to form thin films suitable for semiconductor applications are disclosed. Methods of preparing such liquid precursors and method of depositing a liquid precursor on a substrate are also disclosed.

Claims

1. A method of preparing a liquid precursor, said method comprising the steps:

contacting elemental selenium with an amount of at least one nitrogen-containing agent effective to yield a preliminary precursor solution; and

combining the preliminary precursor solution with a solution of an indium salt to yield the liquid precursor.

2. The method of claim 1 wherein the nitrogen-containing agent is selected from the group consisting of hydrazine, primary amines, secondary amines, and combinations thereof.

3. The method of claim 2 wherein the nitrogen-containing agent is selected from the group consisting of ethylene diamine, pyridine, ethanolamine, diethylene triamine, N-methylimidizole, and combinations thereof.

4. The method of claim 1 wherein the nitrogen-containing agent reduces the elemental selenium.

5. The method of claim 4 wherein the nitrogen-containing agent reduces up to about 50% of the elemental selenium.

6. The method of claim 1 further comprising conducting the step of contacting the elemental selenium and at least one nitrogen-containing agent in the presence of a non-nitrogen containing solvent.

7. The method of claim 6 wherein the non-nitrogen containing solvent is a glycol.

8. The method of claim 1 wherein the solution of indium salt comprises a solvent selected from the group consisting of alcohols, glycols, water, dimethylformamide, primary amines, secondary amines and combinations thereof.

9. The method of claim 1 wherein the solvent for the indium salt is selected from the group consisting of methanol, ethanol, butanol, ethylene glycol, dimethylformamide, and combinations thereof.

10. The method of claim 1 wherein the indium salt is selected from the group consisting of indium nitrate, indium chloride, indium triflate, and combinations thereof.

11. The method of claim 1 wherein the liquid precursor comprises an indium concentration in the range of about 0.10 M to about 0.50 M.

12. The method of claim 1 wherein the nitrogen-containing agent has a standard reduction potential less than the standard reduction potential of selenium.

13. A method of depositing a solid precursor on a substrate, said method comprising the steps of:

obtaining a liquid precursor prepared by the following steps;

a) contacting elemental selenium with an amount of at least one nitrogen-containing agent effective to yield a preliminary precursor solution; and

b) combining the preliminary precursor solution with a solution of an indium salt, to yield the liquid precursor;

applying the liquid precursor to the substrate; and

heating the liquid precursor to a temperature and for a time sufficient to yield the deposited solid precursor on the substrate.

14. The method of claim 13 wherein the deposited solid precursor is a thin film.

15. The method of claim 13 wherein the heating step is conducted at a temperature of at least 250°

C.

16. The method of claim 15 wherein the temperature is from about 250°

C. to about 300°

C.

17. The method of claim 13 wherein the deposited solid precursor is indium selenide at least substantially in the form of InSe.

18. The method of claim 13 wherein the deposited solid precursor comprises elemental selenium.

19. The method of claim 13 wherein the applying step is implemented through a process selected from the group consisting of drop coating, dip coating, spin coating, spraying, brushing, air brushing, ink jet application, stamping, printing, pouring, wiping, smearing, spray deposition, slot coating, and combinations thereof.

20. The method of claim 13 wherein the liquid precursor comprises an indium concentration in the range of about 0.10 M to about 0.50 M.

21. A liquid precursor comprising:

a hydrazine-free solvent for a solute comprising indium and selenium; and

a solute comprising indium and selenium.

22. The liquid precursor of claim 21 wherein indium and selenium are present in a molar ratio of about 1:

1 to 2;

3.

23. The liquid precursor of claim 21 wherein the hydrazine-free solvent is selected from the group consisting of alcohols, glycols, dimethylformamide, water, primary amines, secondary amines and combinations thereof.

24. The liquid precursor of claim 21 wherein the indium concentration is in the range of about 0.10 M to about 0.50 M.