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

• CZTS nanoparticles were used as the HTL to construct n-i-p Sb 2 Se 3 solar cells. • CZTS HTL can effectively suppress the back interface recombination and improve carrier collection efficiency. • A significant efficiency improvement to 6.06% was obtained. Sb 2 Se 3 is an emerging and promising thin-film photovoltaic absorber material. However, for commonly CdS/Sb 2 Se 3 heterojunction device structure, low carrier concentration and back contact barrier will prevent the further improvement of device efficiency. Here we have successfully applied Cu 2 ZnSnS 4 (CZTS) nanoparticles (NPs) as a hole-transport layer (HTL) to construct a low-cost n-i-p Sb 2 Se 3 solar cell with FTO/CdS/Sb 2 Se 3 /CZTS/Carbon configuration. We found that CZTS HTL can effectively suppress the back interface carrier recombination and improve carrier collection efficiency in the Sb 2 Se 3 solar cells. The average J sc , FF , and efficiency of Sb 2 Se 3 solar cells with an optimum CZTS HTL are increased by 10.64%, 7.91%, and 17.14%, respectively, compared with Sb 2 Se 3 solar cells without a HTL. Consequently, with CZTS NPs as HTL and carbon as electrode, the n-i-p Sb 2 Se 3 solar cells have achieved a champion efficiency of 6.06%. [ABSTRACT FROM AUTHOR]