Computation of the Dielectric and Optical Properties of Dimethylammonium Tin Triiodostanate (II) Perovskite for Solar Cell Application

Abstract

Hybrid halide perovskites are promising photovoltaic materials for use in solar cells. The ongoing research on perovskites have shown that these materials are potential light-harvesting mediums. The optical properties of dimethylammonium triiodostanate (II) (DASnI3) a hybrid halide perovskites needs to be studied because it can be a good light absorber material due to the wide band gap exhibited. The real and the imaginary parts of the dielectric is a measure of the extent of light absorption. The GGA+U exchange-correlation implemented in Quantum ESPRESSO was used basing on density functional theory to obtain the optical properties. The DASnI3 has a direct band gap of 2.7 eV with the real part of the dielectric diagram indicating that the maximum value of ε1 (ω) is in the visible range of (3.0–3.5 eV). High absorption peaks were also observed in the visible spectral region at energy of around (3.5–4.5 eV) with several weak peaks observed in the energy range of (4.5–14.0 eV). The band structure and the dielectric functions are important in the study of optical properties. These properties expresses the interaction of light with the material medium and thus the luminescence of the device which are important in the use of DASnI3 as a solar cell material in photovoltaics.