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

Abstract

CuSbS2, a ternary I–V–VI2 chalcogenide material, has recently drawn great attention for use as a promising light absorber for photovoltaics. However, the low open circuit voltage (VOC) remains as a bottleneck for CuSbS2 solar cells which is the limitation of its power conversion efficiency. This could be caused by the severe recombination losses at the interface between CuSbS2 and CdS buffer layers. This work aims to explore the effect of CdS, In2S3, and the In/Cd-based hybrid buffer layers on the device performance of CuSbS2 solar cells. Device parameters, such as current density-voltage (J–V) and spectral response, were measured and compared, band alignment was extrapolated for CuSbS2 with different buffer materials. With the highest measured VOC and short circuit current density (Jsc), reduced series resistance (Rs) and improved shunt resistances leading to the highest fill factor (FF), it has been concluded that the CuSbS2 device with combined CdS/In2S3 buffer layers exhibits the best performance compared to those with other buffer layers.