Numerical analysis of Al/Gr/ETL/MoS2/Sb2S3/Ni solar cell using non-toxic In2S3/SnS2/ZnSe electron transport layer

Abstract

In this study, Molybdenum disulfide (MoS2) based thin film solar cells (TFSCs) of the structure Al/Gr/ETL/MoS2/Sb2S3/Ni have been simulated using SCAPS-1D software. Due to their remarkable properties, three Cd-free and non-toxic (In2S3, SnS2, and ZnSe) electron transport layer (ETL) materials were suggested for MoS2-based TFSCs. The effect of various layer parameters on the performance of the cells was investigated for various ETL materials. The considered parameters are the MoS2 absorber layer thickness, the carrier density and thickness of the ETL, and the ETL/MoS2 interface defect density, as well as the impact of the working temperature, series resistance, and shunt resistance. The simulation results show that the highest power conversion efficiency is achieved for the MoS2 absorber layer thickness of 1.0 µm, and the thickness and carrier density of different ETLs of 0.05 µm and 1016 cm-3, respectively. We found that the defect density of the ETL/MoS2 interface should be controlled under 1012 cm-2. The optimized power conversion efficiencies of MoS2-based TFSCs are found by simulation 27.88%, 28.22%, and 28.29% for the cell with In2S3, SnS2, and ZnSe ETL, respectively. Among the three ETL materials used, zinc selenide (ZnSe) shows the best results due to its wider band gap. We have found that the cells with the FTO window layer show slightly better performance than those with the graphene. Maximum photovoltaic efficiency of 28.54% has been achieved for the solar cell of the structure Al/FTO/ZnSe/MoS2/Sb2S3/Ni. The results of simulations reveal that high-efficiency MoS2 solar cells with non-toxic (In2S3, SnS2, and ZnSe) ETLs can be obtained. Overall, the numerical simulation conducted in this study could contribute to the manufacture of Cd-free non-toxic and highly efficient MoS2-based solar cells.