Theoretical analysis of the effect of conduction band offset of window/CIS layers on performance of CIS solar cells using device simulation

One of the most important factors of CdS leading to high performance in Cu(In,Ga)Se2 (CIGS) solar cells is appropriation of the conduction band offset of CdS/CIGS layers. However, it is not clearly explained. In this study, device modeling and simulation were conducted to explain the effect of conduction band offset of window/CIGS layers on performance of CIGS solar cells. As a result of calculation, excellent performance can be obtained when the conduction band of window layer positions higher by 0–0.4 eV than that of CIGS.