Numerical Optimization of Lead Free Perovskite Solar Cell

Abstract

Alternative perovskite solar cells are emerging rapidly to compete with other conventional photovoltaic materials. However, toxic lead content of organic-inorganic perovskite is an issue to be addressed briefly. In this work, we propose to use organo-tin halide perovskite absorber layer to replace toxic Pb-based light harvester. We perform a numerical optimization of the layer thicknesses both from the optical and electrical points of view, using SCAPS (Solar Cell Capacitance Simulator) and analytical calculations. We study two types of electron conducting materials (n-ZnO and n-TiO₂). Both ZnO/CH₃NH₃SnI₃/Spiro-OMETAD and TiO₂/CH₃NH₃SnI₃/Spiro-OMETAD structures show the conversion efficiencies above 15% of (respectively 15.44% and 15.64%). Accordingly, we present a fully optimized device architecture. The analyzed results indicate the feasible fabrication of high efficiency Pb-free perovskite solar cells.