CuSbS2 Solar Cells Using CdS, In2S3 and the In/Cd-based Hybrid Buffers

CuSbS 2 , a ternary I–V–VI 2 chalcogenide material, has recently drawn great attention for use as a promising light absorber for photovoltaics. However, the low open circuit voltage ( V OC ) remains as a bottleneck for CuSbS 2 solar cells which is the limitation of its power conversion efficiency. This could be caused by the severe recombination losses at the interface between CuSbS 2 and CdS buffer layers. This work aims to explore the effect of CdS, In 2 S 3 , and the In/Cd-based hybrid buffer layers on the device performance of CuSbS 2 solar cells. Device parameters, such as current density-voltage ( J–V ) and spectral response, were measured and compared, band alignment was extrapolated for CuSbS 2 with different buffer materials. With the highest measured V OC and short circuit current density ( J sc ), reduced series resistance ( R s ) and improved shunt resistances leading to the highest fill factor (FF), it has been concluded that the CuSbS 2 device with combined CdS/In 2 S 3 buffer layers exhibits the best performance compared to those with other buffer layers.