A numerical study of CsSnIxBr3-xperovskite material as an electron transport layer (ETL), in the perovskite solar cell of a photovoltaic system by molecular dynamics method with LAMMPS software: The effects of external convective heat transfer

In this study, we first simulated the structure of perovskite by molecular dynamics with LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator) software. Then, by applying temperature to the structure of perovskite, we investigated the impacts of temperature fluctuations on the perovskite layer. We calculated the melting point and volume increase using external heat to the structure. We used the CsSnIxBr3-x perovskite material, widely used in biostructures, inside the perovskite solar cell, acting as an ETL. Then by applying this material to a photovoltaic structure referring to the solar cell made of perovskites, we calculated the efficiency and fill factor; the efficiency of CsSnI3, CsSnI2Br, and CsSnIBr2 perovskite-based solar cell was 26.43%, 26.28%, and 22.47%, respectively. The FF for CsSnI3, CsSnI2Br, and CsSnIBr2 perovskite-based solar cell was 79.37%, 80.34%, 80.58%. Also, after applying 270 K, 300 K, and 330 K temperatures to the CsSnI3, CsSnI2Br, and CsSnIBr2 perovskite atomic structure, the maximum stress was equal to 20.592 GPa, 15.582 GPa, and 13.590 GPa for CsSnI3, CsSnI2Br, and CsSnIBr2, respectively. The mechanical properties of CsSnI3, CsSnI2Br, and CsSnIBr2 perovskites have been investigated theoretically using molecular dynamics computer simulations. By applying a specific tensile load, we successfully obtained the stress-strain behavior of CsSnI3, CsSnI2Br, and CsSnIBr2 pe-rovskites, as well as Young's modulus corresponding to different perovskite materials: The Young's modulus of CsSnI3, CsSnI2Br, and CsSnIBr2 perovskites were 4.615 GPa, 4.160 GPa, and 4.004 GPa, respectively.