Efficiency improvement of antimony selenide solar cells based on S-doped SnO2 buffer layer

Abstract

Antimony Selenide (Sb2Se3) exhibits potential as a solar energy material owing to its optimal bandgap, lack of toxicity, and abundance of earth abundant elements. Currently, cadmium sulfide (CdS) serves as the predominant buffer layer for Sb2Se3 solar cells. However, the use of CdS hinders environmentally friendly advancement due to the toxic properties of the element cadmium. Hence, the quest for non-toxic buffer layers poses a significant challenge to the further advancement of Sb2Se3 solar cells. In prior research, tin oxide (SnO2) has been explored as a buffer layer. Nonetheless, the efficiency of SnO2/Sb2Se3 solar cells was hampered by the rough surface of SnO2 films and the poor crystallinity of Sb2Se3 films. In this investigation, we enhanced device efficiency by improving the uniformity of the SnO2 surface and enhancing the crystallinity of Sb2Se3 through spin-coating sulfur (S) onto the SnO2 film. Detailed examinations were conducted on the structure, optical, and electrical properties of the respective SnO2 and Sb2Se3 thin films. Ultimately, an efficiency of 3.38% was achieved using the spin-coated S:SnO2 film, marking an 85% enhancement compared to the baseline device.