Numerical simulation and performance optimization of Sb2S3 solar cell with a hole transport layer

Abstract

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.