Performance Optimisation of CH3NH3SnI3 Based Perovskite Solar Cells: A Drift-Diffusion Approach
Abstract
This study investigates the drift-diffusion behavior in tin-based perovskite solar cells, specifically focusing on CH3NH3SnI3, with the aim of understanding how ion mobility, hysteresis, recombination mechanisms, and material parameters influence device performance. Tin-based perovskites represent a promising alternative to lead-based compounds due to their reduced toxicity and comparable optoelectronic properties, yet they pose challenges related to stability and efficiency. A numerical model was developed by solving the coupled Poisson and continuity equations, incorporating both electronic and ionic transport phenomena. The simulation framework allows for variation in ion mobility, defect density, recombination rates, and built-in potential, enabling a comprehensive analysis of dynamic and steady-state responses. The results reveal a significant dependence of hysteresis behavior on ion migration and recombination at interfaces, as well as a notable impact of ionic mobility on current–voltage characteristics and power conversion efficiency. Furthermore, the model shows that optimization of material parameters can mitigate hysteresis and enhance device stability and output. These findings provide valuable insights into the physical mechanisms limiting the performance of tin-based perovskite solar cells and suggest strategies for their improvement through targeted material and device engineering.