Enhancement in the efficiency of Sb2Se3 solar cells by adding low lattice mismatch CuSbSe2 hole transport layer

Abstract

As an excellent light absorbing material, antimony selenide (Sb2Se3) has attracted researchers to explore its application in solar cells. At present, the efficiency of Sb2Se3 solar cells is still too low because of the low carrier concentration and high back surface recombination. In this study, we prepared an additional CuSbSe2 film as hole transport layer by co-sputtering Sb2Se3 and Cu targets. It reduced the surface roughness of the absorption layer and the back surface recombination, which was beneficial to the collection of carriers. Due to the higher carrier concentration of CuSbSe2 film and proper diffusion of Cu, the carrier concentration of the absorption layer is greatly improved, thereby effectively increasing the Voc of the Sb2Se3 thin film solar cells. Finally, we obtained a 5.87% efficiency for the FTO/CdS/Sb2Se3/CuSbSe2/Au solar cell, which is more than 25% higher than the basic efficiency.