First-principles calculations for fundamental and spectroscopic screening of hybrid perovskite (HC(NH2)2PbI3) formamidinium lead iodide

Formamidinium lead iodide [(HC(NH2)2PbI3] material has generated significant interest in their inherent properties and extensive scope of prospective applications. Here, we have successfully computed the structural, electronic, optical, thermal, thermoelectric and elastic properties with the framework of density functional theory over the PBE-sol and WC potential approximations using the WIEN2K code. These explorations show that this material is a direct bandgap semiconductor (1.30 eV), with high absorption coefficients and better thermal stability. The dielectric function and absorption spectra peaks reveal in the IR-visible-UV energy region show the significant future of this material to be used in photovoltaic (PV) devices. Thermal properties have been calculated by GIBBS2 at different temperatures (0–800 K) and pressures (0–8 GPa). Boltztrap with constant relaxation time approximation has been used for computing the thermoelectric parameters at different temperatures (300–800 K). Seebeck coefficient decreases with increasing temperature, electrical conductivity nearly constant in the whole temperature ranges, electrical thermal conductivity increases with increasing temperature, power factor and figure of merit's are also increasing with increasing temperature at a given electron and hole concentration (1018-1019 cm−3). We have also carried out the calculations of spectroscopic limited maximum efficiency (SLME) parameter (39.09%). Moreover, for mechanical stability, we have determined the elastic properties (C11, C12, C44), bulk modulus (B), Young's modulus (Y), shear modulus (G) and stability constants B/G ratio, and Poisson's ratio (ν). These computed results show that the FAPbI3 is a relevant material to be used as an alert substance in photovoltaic device fabrications and proposed outcomes are in good acceptance with the experimental and other theoretical data.