Utilizing Density Functional Theory and SCAPS Simulations for Modeling High‐Performance MASnI3‐Based Perovskite Solar Cells

This study uses computational analysis to comprehensively investigate lead‐free organic–inorganic CH 3 NH 3 SnI 3 (MASnI 3 )‐based perovskite solar cells (PSCs). The optoelectronic properties of MASnI 3 are investigated using density functional theory with first‐principles calculations, highlighting its potential for photovoltaic applications. Key findings include the determination of a crucial bandgap (0.97 eV), identification of the onset of photon absorption at energies exceeding 2 eV, and characterization of material properties, such as the absorption and extinction coefficients, reflectivity, and refractive index. Device optimization through simulations explores parameters such as layer thickness, defect density, and different charge transport layers, resulting in a remarkable enhancement in the power conversion efficiency to 16.72%. Additionally, this study focuses on the influence of the working temperature, series resistance ( R s ), and shunt resistance ( R sh ) on the photovoltaic device performance. Hence, a high photovoltaic efficiency in MASnI 3 ‐based PSCs can be achieved by carefully optimizing the device performance parameters and effectively managing the defect densities.