Enhanced open circuit voltage of Sb2Se3/CdS solar cells by annealing Se-rich amorphous Sb2Se3 films prepared via sputtering process

Abstract

Thin film solar cells of Sb2Se3 undergo a significant carrier recombination loss, which impedes the further improvement of their efficiency. This is due to the intrinsic defects caused by selenium deficiency, such as the selenium vacancy and SbSe antisite. Therefore, the selenium-enriched precursor film is effective in preventing the formation of this profound defect and improve the performance of the Sb2Se3 thin film solar cells. However, there are only a very few reports that incorporate the use of a precursor to deposit Sb2Se3 films. Herein, we initially prepared selenium-rich Sb2Se3 films by sputtering selenium-rich Sb2Se3 targets, and subsequently prepared the same films by simple annealing. It was observed that the substrate structure of the Sb2Se3 thin film solar cell which was constructed by annealing at 400 °C had the best performance with an efficiency of 4.22% and an open circuit voltage (Voc) of 454 mV; this was a high Voc level for a Sb2Se3 solar cell. The significant improvement of Voc represents a remarkable potential to improve the power conversion efficiency of Sb2Se3 solar cells.