CuSbSe2 photovoltaic devices with 3% efficiency

Abstract

Recent technical and commercial successes of existing thin-film solar cell technologies encourage the exploration of next-generation photovoltaic (PV) absorber materials. Of particular scientific interest are compounds that do not exhibit conventional tetrahedral semiconductor bonding, such as CuSbSe2. CuSbSe2 has a 1.1 eV optical absorption onset, a 105 cm-1 absorption coefficient, and a hole concentration of 1017 cm-3. Here, we demonstrate CuSbSe2 PV prototypes with efficiencies >3%, prepared by a self-regulated sputtering process using a conventional substrate device architecture. Bulk recombination, device engineering issues, and a nonideal CuSbSe2/CdS band offset likely limit the promising initial result.