Abstract:
The present invention provides a CIGS film production method which ensures that a CIGS film excellent in conversion efficiency can be produced at lower costs with higher reproducibility, and a CIGS solar cell production method using the CIGS film production method. The CIGS film production method includes: a stacking step of stacking an (A) layer containing indium, gallium and selenium and a (B) layer containing copper and selenium in this order in a solid phase over a substrate while heating at a temperature of higher than 250° C. and not higher than 400° C.; and a heating step of further heating the resulting stack of the (A) layer and the (B) layer to melt a compound of copper and selenium in the (B) layer into a liquid phase, whereby copper is diffused from the (B) layer into the (A) layer to cause crystal growth to provide a CIGS film.