A study of single-/multi-layer structures of CH3NH3SnI3 by density functional theory

Two-dimensional perovskites are promising candidates in optoelectronic applications due to their good optical properties and high stability. In this work, we report the results of our studies on the structural, electronic, and optical properties of the single-/multi-layer structures of CH3NH3SnI3 by density functional theory. The electronic calculation predicts that the single-/multi-layer structures of CH3NH3SnI3 have the direct band gaps of 1.34 and 1.23 eV, respectively. These energy band gap values are in good agreement with the sunlight absorption zones. The densities of states for these structures show that the elements Sn and I play an important role in the electronic properties of the layered perovskites. Furthermore, the results obtained from calculation of the optical properties depict that a large static dielectric constant is important and prohibits electron-hole recombination in the solar cell applications. Finally, the absorption, reflectivity, and loss function of single-/multi-layered structures of CH3NH3SnI3 show the high potentials of these structures in the production of perovskite-based solar cells.