CZTS nanoparticles as an effective hole-transport layer for Sb2Se3 thin-film solar cells

Abstract Sb2Se3 is an emerging and promising thin-film photovoltaic absorber material. However, for commonly CdS/Sb2Se3 heterojunction device structure, low carrier concentration and back contact barrier will prevent the further improvement of device efficiency. Here we have successfully applied Cu2ZnSnS4 (CZTS) nanoparticles (NPs) as a hole-transport layer (HTL) to construct a low-cost n-i-p Sb2Se3 solar cell with FTO/CdS/Sb2Se3/CZTS/Carbon configuration. We found that CZTS HTL can effectively suppress the back interface carrier recombination and improve carrier collection efficiency in the Sb2Se3 solar cells. The average Jsc, FF, and efficiency of Sb2Se3 solar cells with an optimum CZTS HTL are increased by 10.64%, 7.91%, and 17.14%, respectively, compared with Sb2Se3 solar cells without a HTL. Consequently, with CZTS NPs as HTL and carbon as electrode, the n-i-p Sb2Se3 solar cells have achieved a champion efficiency of 6.06%.