Design and simulation of Sb2S3 solar cells based on monolayer graphene as electron transport layer

Abstract In Sb2S3 solar cells, the p-n junction are generally formed by combination of p-type Sb2S3 absorber layer and n-type materials, such as CdS and TiO2. In this study, the design and simulation of the Sb2S3 solar cells with graphene as electron transport layer were performed. The device performance parameters with respect to the electron affinity of monolayer graphene, the doping concentration, thickness and bulk defect density of Sb2S3 layer were examined and optimized. The simulation results revealed that the performance of Sb2S3 solar cells could be improved by using a monolayer graphene with lower value of electron affinity. The optimum doping concentration of Sb2S3 absorber layer was found to be 1017 cm−3. Also, the optimum Sb2S3 absorber layer thickness was found to be 0.7 μm when the bulk defect density and the corresponding carrier diffusion length were 1015 cm−3 and 1.6 μm, respectively. According to the optimum values of different variables, the conversion efficiency of the Sb2S3 solar cells could be achieved as high as 23.30%. These results showed that the monolayer graphene could be served as an efficient and inexpensive electron transport layer.