A Detailed Study of Cu(In,Ga)Se_2 Thin Films by Electron-Beam-Induced-Current and Cathodoluminescence

摘要

Cu(In,Ga)Se_2 (CIGS) thin films were deposited using the three-stage process. At the third stage, an amount of Indium was added to the CIGS that is greater than the standard used in processing high-efficient CIGS solar cells. The effects of Indium excess and substrate temperature were then investigated by electron-beam-induced-current (EBIC) and Cathodoluminescence (CL). The addition of more indium compared to the standard noticeably affects the ZnO/CdS/CIGS heterojunction. On the other hand, the substrate temperature primarily affects the luminescence behavior of these films. It is suggested than In enrichment and Na incorporation play a main role in the electronic properties of the film. From these results, the efficiencies obtained for this set of CIGS cells are finally understood.