Performance optimization of lead-free MASnBr3 based perovskite solar cells by SCAPS-1D device simulation

Perovskites are at the forefront of research into potential alternatives for bulky and costly silicon-based solar cells. In recent years, lead-based organic and inorganic perovskite solar cells have broken efficiency records. However, these have stability issues and may pose health risks in the long-term. Hence, there has been ideally inorganic perovskite solar cells and parallel search for lead-free to match and eventually surpass the achievements of lead perovskite analogues. This study reports a modelling-guided device optimization process to design highly efficient lead-free n-i-p methyl ammonium tin bromide (MASnBr3) perovskite solar cells. We have studied the effect of the various hole and electron transport layers on the performance of MASnBr3 devices. The influence of different parameters, such as doping concentration of optimized HTLs/ETLs, the thickness of the perovskite layer, NA/ND of the absorption layer, and the defect density, is thoroughly investigated using numerical simulations. An optimized device FTO/SnO2/MASnBr3/NiO/Au is proposed here with an open circuit voltage of 1.1214 V, a short circuit current density of 34.8654 mA/cm2, fill factors of 88.30%, a theoretical power conversion efficiencies of 34.52%, and quantum efficiencies of 98%. This work reveals the potential of the MASnBr3 material as a perovskite for toxicity-free renewable energy.