Interface Investigation of ZnO/CdS/CuIn 1−x Ga x Se 2 /Mo Solar Cells

Graded-band-gap CuIn 1−x Ga x Se 2 (CIGS) absorbers with Ga/Ga+In value in the 20%–30% range have a demonstrated efficiency of 18.8%. For CdS-containing devices, the shortcircuit current density (J sc ) has almost reached its expected maximum. However, the open-circuit voltage of CIGS solar cells is limited by the surface microstructure and chemistry. In this work, we examine the microstructural properties and chemistry of CIGS. We also attempted to correlate the above observations and device performance.