The effect of sodium on antimony selenide thin film solar cells
Sodium (Na) has been identified as a benign contaminant in some thin film solar cells. Here, we have studied the impact of sodium on the properties of CdS/Sb2Se3 superstrate thin film solar cells. NaF deposited at the CdS/Sb2Se3 heterojunction severely degraded the device performance, yet NaF introduced into the Sb2Se3 film after the completion of the heterojunction showed a negligible influence on the film conductivity and device performance. We concluded that sodium could easily diffuse into the Sb2Se3 film and probably locates in the gap between (Sb4Se6)n ribbons, being inert in Sb2Se3 solar cells.