CuInGaSe2/CdS thin film solar cells made with new precursors prepared by sputtering

CuInGaSe2/CdS thin film solar cells have been prepared by using only sputtering and selenization in a Se vapour. First of all, a precursor for the formation of a thin film of CuInSe2 is prepared on a one inch square soda-lime glass by sputtering in sequence Mo, In2Se3 and Cu. The staked layers are annealed at 400°C for half an hour and then selenized at 530°C for 10 minutes. In this way, a uniform CuInSe2 film is obtained. In order to get a CuInGaSe2 film, an alloy of Cu-Ga is deposited by sputtering on top of CuInSe2 and the stacked CuInSe2/Cu-Ga is selenized at 530°C for 10 minutes. Solar cells are prepared by depositing in sequence CdS, intrinsic ZnO and Al-doped ZnO. 14% uniform efficiencies on 1 inch square area are easily obtained. Since this process uses only sputtering and selenization techniques, it is suitable to be scaled-up to large area production.