LAUSR

Abstract Antimony sulfide (Sb2S3) solar cell is considered to be an emerging photovoltaic device technology. However, the conversion efficiency of Sb2S3 solar cell remains limited to lower than 8%. To boost the conversion efficiency, a device structure consists of FTO/ZnS/Sb2S3/Cu2O/Au was proposed and the device photovoltaic performance has been numerical simulated by wxAMPS. The initial values of bulk defect density in Sb2S3 layer and interface defect density at ZnS/Sb2S3 and Sb2S3/Cu2O interfaces are set to be 1016 cm−3, 1010 cm−2 and 1010 cm−2, respectively. The conversion efficiency increases from 6.24% to 16.65% by incorporating a Cu2O layer into the solar cell. The influence of Sb2S3 bulk material quality on device photovoltaic performance was also analyzed. It is important to note that a proper higher carrier diffusion length than the thickness of Sb2S3 layer should be guaranteed to facilitate the conversion of photogenerated electron-hole pairs to photogenerated current. It is feasible to achieve a value of 1015 cm−3 for bulk defect density in Sb2S3 layer (corresponding diffusion length is calculated to 1.6 μm) in further experimental work, then the optimized conversion efficiency of 21.99% at an optimized Sb2S3 layer thickness of 0.8 μm could be arrived. Furthermore, the influence of interface defects at ZnS/Sb2S3 and Sb2S3/Cu2O interfaces on device photovoltaic performance were also analyzed. It is feasible to achieve a value of 109 cm−2 for interface defect density at ZnS/Sb2S3 and Sb2S3/Cu2O interfaces and a best conversion efficiency of 22.78% can be obtained.