The effect of thickness on the Sb2Se3 superstrate solar cells

In this study, we analyze the impact of different thickness of antimony selenide thin films on the electrical properties of the absorber and on the efficiency of the finished solar cells. Sb2Se3 absorbers have been deposited with different thickness: from 400 nm to 1200 nm, grown by thermal evaporation on CdSe buffer layer in superstrate configuration. The highest efficiency has been delivered by the thinner absorber, with a large absorption spectrum, a higher quantum efficiency response, and a higher carrier concentration. Moreover, a post-annealing treatment in air at 150 °C, improves the efficiency of the cells with a larger impact on the thinnest absorber, increasing the Voc and correcting the rollover effect observed in the current voltage curve of the thicker absorber layers.