Method for manufacturing CIGS thin film for solar cell

Patent metadata

Field	Value
Publication number	US-10446703-B1
Application number	US-201816023859-A
Country	US
Kind code	B1
Filing date	Jun 29, 2018
Priority date	Apr 17, 2018
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

Methods of manufacturing a CIGS thin film for a solar cell are provided. According to the method, a CIGS thin film having an ideal double band gap grade structure with a large particle size may be obtained by heat-treating a solution-treated CIG oxide thin film by a three-step chalcogenization process. Accordingly, performance of the solar cell may be improved.

First claim

What is claimed is:

1. A method of manufacturing a CIGS thin film for a solar cell, the method comprising:
first heat-treating a CIG oxide thin film coated on a substrate by a solution process, the heat-treating being performed under an inert gas atmosphere;
second heat-treating the CIG oxide thin film while supplying a gaseous phase selenium precursor to the CIG oxide thin film, thereby forming a Cu 2−x Se (0≤x<1) phase; and
third heat-treating the thin film in which the Cu 2−x Se phase is formed under an atmosphere comprising a gaseous phase sulfur precursor, thereby forming a CIGS thin film.

2. The method of claim 1 , wherein the first heat-treating is performed at a temperature of about 200° C. to about 400° C. for about 5 minutes to about 90 minutes.

3. The method of claim 1 , wherein the second heat-treating comprises raising a temperature to a higher temperature than that of the first heat-treating.

4. The method of claim 1 , wherein the second-treating is performed by heat-treating the CIG oxide thin film at a temperature of about 200° C. to about 600° C. for about 5 minutes to about 120 minutes under an inert gas atmosphere while supplying the gaseous phase selenium precursor to the CIG oxide thin film.

5. The method of claim 1 , wherein the gaseous phase selenium precursor is selenium vapor.

6. The method of claim 1 , wherein the third heat-treating comprises raising a temperature to a higher temperature than that of the second heat-treating.

7. The method of claim 1 , wherein the third heat-treating is performed by increasing the temperature stepwise from the temperature of the second heat-treating.

8. The method of claim 1 , wherein the third heat-treating is performed at a temperature about 10° C. to about 100° C. higher than that of the second heat-treating.

9. The method of claim 1 , wherein the gaseous phase sulfur precursor is H 2 S.

10. The method of claim 1 , wherein the CIG oxide thin film is obtained by coating a solution comprising Cu, In, and Ga precursors in an alcohol solvent on the substrate and heat-treating the coated solution under an air atmosphere.

11. The method of claim 10 , wherein the coating is performed by at least one solution process selected from spin coating, doctor blading, and screen printing.

12. The method of claim 1 , wherein the substrate comprises at least one selected from molybdenum, fluorine tin oxide, and indium tin oxide.

13. The method of claim 1 , wherein the CIGS thin film has a double band gap grade structure.

14. A method of manufacturing a junction structure of a buffer layer and a CIGS thin film for a solar cell, the method comprising:
manufacturing a CIGS thin film for a solar cell according to the method of claim 1 ; and
forming a buffer layer comprising cadmium zinc sulfide on the CIGS thin film.

15. A method of manufacturing a solar cell, the method comprising:
forming a CIGS thin film on a first electrode by using the method of claim 1 ; and
forming a second electrode on the CIGS thin film.

16. The method of claim 15 , wherein the first electrode comprises at least one selected from molybdenum, fluorine tin oxide, and indium tin oxide.

17. The method of claim 15 , wherein the second electrode comprises at least one selected from molybdenum, fluorine tin oxide, indium tin oxide, nickel, and aluminum.

18. The method of claim 15 , wherein the solar cell further comprises a buffer layer comprising cadmium zinc sulfide.

Assignees

• Korea Inst Sci & Tech

Inventors

• Min Byoung Koun
• Park Gi Soon
• Oh Hyung Suk
• Hwang Yun Jeong

Classifications

• C23C16/305

  Sulfides, selenides, or tellurides · CPC title

• C23C16/0218

  in a reactive atmosphere (C23C16/0227 takes precedence) · CPC title

• H01L31/0272

  Electricity · mapped topic

• H01L31/0322 Primary

  Electricity · mapped topic

• H01L31/03923

  Electricity · mapped topic