Thin films of copper antimony sulfide: A photovoltaic absorber material

In this work, we report preparation and characterization of CuSbS2 thin films by heating glass/Sb2S3/Cu layers and their use as absorber material in photovoltaic structures: glass/SnO2:F/n-CdS/p-CuSbS2/C/Ag. The Sb2S3 thin films of 600 nm were prepared by chemical bath deposition on which copper thin films of 50 nm were thermally evaporated, and the glass/Sb2S3/Cu multilayers were heated in vacuum at different temperatures. X-ray diffraction analysis showed the formation of orthorhombic CuSbS2 after heating the precursor layers. Studies on identification and chemical state of the elements were done using X-ray photoelectron spectroscopy. The optical band gap of the CuSbS2 thin films was 1.55 eV and the thin films were photoconductive. The photovoltaic parameters of the devices using CuSbS2 as absorber and CdS as window layer were evaluated from the J–V curves, yielding Jsc, Voc, and FF values in the range of 0.52–3.20 mA/cm2, 187–323 mV, and 0.27–0.48, respectively, under illumination of AM1.5 radiation.