Hole and Electron Transport Layer Optimization for Highly Efficient Lead-Free MASnI2Br Perovskite Solar Cells: A Simulation Study

Lead-free perovskite solar cells have become attractive as they are more environmentally friendly than their lead-based counterparts. Among these lead-free perovskite materials is MASnI2Br, which has attracted considerable attention due to its environmentally friendly advantages and beneficial optoelectronic properties. However, further enhancement is required in order to improve the power conversion efficiencies. In this study, an MASnI2Br-based perovsdkite solar cell is designed and optimized using SCAPS-1D simulations. An extensive iterative simulation approach is carried out to optimize critical parameters such as electron affinity, energy bandgap, layer thickness and doping concentration for both transport layers. In addition, the thickness of the MASnI2Br absorbing layer is optimized. With the improved device setup, the maximum achievable power conversion efficiency is 24%. Furthermore, by matching the optimized electronic structure with realistic transport materials, CBTS and TiO2 are identified as suitable hole and electron transport layers, respectively. The proposed TiO2/MASnI2Br/CBTS perovskite solar cell has a power conversion efficiency of about 23.6%.