Characterization of sulfurized CuSbS2 thin films for PV applications

CuSbS₂ is emerging as a novel absorber for sustainable photovoltaics. We fabricated CuSbS₂ thin films by the sulfurization of sputtered metallic layers. Characterization of the morphological, optical, electrical and surface properties is presented. Overpressure of inert gas during sulfurization reduced antimony loss. The largely single-phase films exhibit optimal characteristics for PV applications, including a band gap of about 1.5 eV and p-type conductivity. The carrier concentrations were ~10¹⁷ cm^-3 and the mobility was generally about 10 cm² V^-1 s^-1. Surface property measurements are dominated by Sb₂O₃ and a secondary phase may be responsible for PL emission above the optical gap.