Computational determination of the physical-thermoelectric parameters of tin-based organomatallic halide perovskites (CH3NH3SnX3, X = Br and I): Emerging materials for optoelectronic devices

The promising material hybrid Organic-Inorganic Perovskites (HOIP) has been frequently a subject of comprehensive and intensive experimental and theoretical studies. As Because of noxiousness and longtime environmental stability of heavy metal lead, since last few years non-lead based perovskites compounds either organic or inorganic are attracting attention in the solar cell formation. In this work, we have studied the fundamental properties of CH3NH3SnI3 and CH3NH3SnBr3 like structural, electronic, optical and thermoelectric. We have been used full-potential linearized augmented plane wave method (FP-LAPW) within density functional theory (DFT) and implement it in Wien2k. The generalized gradient approximation (GGA) of Perdew-Burke-Ernzerhof (PBE) for the exchange-correlation functional has been used to relax the structural parameters of these materials. The electronic properties have been evaluated by using different GGA and LDA (Local density approximation) exchange correlation potential. We have obtained the values of band gap 1.172 eV and 1.902 eV for CH3NH3SnI3 and CH3NH3SnBr3 respectively by TB-mBJ exchange-correlation potential. According the optical properties, we have seen that because of high absorption coefficient of CH3NH3SnI3 and CH3NH3SnBr3 perovskites, they may be strongly applied in photovoltaic device for the visible to ultra-violet wavelength region. Thermoelectric properties have shown that at room temperature they also may be used as thermoelectric device. Based on my knowledge, the investigations on tin based perovskites have been discussed for first time.