Investigating the band gap on the performance of tin-based perovskite solar cells by device simulation

In recent years, perovskite solar cells (PSCs) have been developed rapidly, and non-toxic tin-based perovskite solar cells have become a hot spot for research in order to achieve rapid commercialization of solar energy. In the present work, the effect of band gap on the device performance of CH 3 NH 3 SnI 3 (MASnI 3 ) tin-based perovskite solar cells was investigated using SACPS-1D (Solar Cell Capacitance Simulator). The results show that the absorber layer band gap is taken between 1.2 and 1.56 eV, and the open-circuit voltage V OC tends to increase as the band gap increases, while other device performance parameters short-circuit current J SC , fill factor FF and photoelectric conversion efficiency PCE tend to decrease. To explain the reasons, this work analyzes the changes of external quantum efficiency, valence band highest energy level E V , hole carrier density, potential barrier, and recombination rate when the band gap is changed using SCAPS, and explores the internal mechanism affecting each device performance parameter. Finally, it is verified that the band gap can be tuned by doping to achieve the stability of each parameter of the material.