CuSbSe2 as a Potential Photovoltaic Absorber Material: Studies from Theory to Experiment

CuSbSe2 appears to be a promising absorber material for thin-film solar cells due to its attractive optical and electrical properties, as well as earth-abundant, low-cost and low-toxic constituent elements. However, no photovoltaic device has been reported based on this material so far, and little information on physical properties such as defect properties, Raman spectrum and temperature-dependent band gap energy is available. Here we report the first CuSbSe2 thin film solar cell (FTO/CuSbSe2/CdS/ZnO/ITO/Al) through a hydrazine-based solution process, achieving a solar power conversion efficiency (PCE) of 1.32%. Using density functional theory (DFT) calculations, we show that CuSbSe2 has benign defect properties, i.e., free of recombination-center defects, and flexible defect and carrier concentration which can be tuned through the control of growth condition. Next, deeply systematic material, optical and electrical characterization indicates that CuSbSe2 is a very promising solar cell absorber. Finally, the obtained 1.32% preliminary efficiency further confirms the great potential of CuSbSe2 for thin-film solar cell applications.