Structural and optoelectronic properties of CsSnBr3 metal halide perovskite as promising materials toward novel-generation optoelectronics

Abstract

In this study, first-principles density functional theory (DFT) calculations of the structural and optoelectronic properties of Sn-based inorganic metal halide perovskite CsSnBr3 are carried out and discussed in details. The Wu-Cohen (WC)-Generalized Gradient Approximation (GGA) based on the full-potential linearized augmented plane-wave (FPLAPW) method is used to optimize the geometry structure of unit cell and then find the accurate optoelectronic properties of CsSnBr3. Analysis of structural optimization results revealed that the lattice parameters (𝑎0 = 5.776 Å) and unit cell volume of CsSnBr3 are exactly consistent with the experiments reports. Based on the results of band structures and density of states, CsSnBr3 is found to be nonmagnetic semiconductor with suitable direct band gap of (Eg = 0.610 eV) along the R symmetry point. In addition, the calculations of optical properties of CsSnBr3, such as the real 𝜀1 (𝜔) and imaginary 𝜀2 (𝜔) parts of the dielectric function, 𝜀(𝜔), absorption coefficient 𝛼(𝜔), reflectivity 𝑅(𝜔) and refractive index 𝑛(𝜔), have been performed in the photonic energy range of (0.0 – 15.0 eV). Finally, the results attained in the present study, which include the stable crystal structure and the high accurate optoelectronic properties such as appropriate direct band gap and high absorption of visible radiation, confirm the possible utilization of CsSnBr3 materials in novel optoelectronics applications as photovoltaic solar cells, photosensors, photodetectors, photodiodes and other related optoelectronics devices