An effective combination reaction involved with sputtered and selenized Sb precursors for efficient Sb2Se3 thin film solar cells

Sputtering followed by post annealing is extensively used for fabrication of copper indium gallium selenide (CIGS), copper zinc tin sulfide (CZTS) and copper zinc tin sulfur selenide (CZTSSe) thin film solar cells. In this work, Sb 2 Se 3 as an emerging alternative absorber was fabricated by an effective combination reaction of annealing sputtered Sb metallic precursors under Se vapor. Self-assembled growth of Sb 2 Se 3 thin films consist of large grains that across the whole films have been successfully fulfilled via this combination reaction. Sb 2 Se 3 thin films with desired orientation, stoichiometric composition and high-quality Sb 2 Se 3 /CdS heterojunction could be achieved once a proper selenization scenario was employed. Further, by selecting Sb films as precursors, the thickness of interfacial MoSe 2 located at the back-contact region can be well controlled, leading to a significant enhancement in fill factor (FF) of the devices. This is in good accordance with our DFT simulation results which demonstrated Se vapor would be prone to react with the Sb lattice thermodynamically and thus limiting the thickness of the MoSe 2 layer. Finally, a champion Sb 2 Se 3 thin film solar cell with power conversion efficiency of 6.15% was achieved, which represents the highest efficiency of sputtered Sb 2 Se 3 solar cells.