Method of fabricating copper indium gallium selenide (cigs) thin film for solar cell using simplified co-vacuum evaporation and copper indium gallium selenide (cigs) thin film for solar cell fabricated by the same

Abstract

A method of fabricating a CIGS thin film for solar cells using a simplified co-vacuum evaporation process and a CIGS thin film fabricated by the method are disclosed. The method includes: (a) depositing Cu, Ga and Se on a substrate having a substrate temperature ranging from 500° C. to 600° C. through co-vacuum evaporation, (b) depositing Cu, Ga, Se and In through co-vacuum evaporation while maintaining the same substrate temperature as in step (a), and (c) depositing Ga and Se through co-vacuum evaporation, followed by depositing Se alone through vacuum evaporation while lowering the temperature of the substrate. The method can realize crystal growth and band-gap grading by Ga composition distribution while simplifying process steps and significantly reducing a film-deposition time, as compared with a conventional co-vacuum evaporation process, thereby providing improvement in process efficiency.