Extensive investigation of structural, electronic, optical, and thermoelectric properties of hybrid perovskite (CH3NH3PbBr3) with mechanical stability constants

Summary Recently, Organometallic halide based perovskites have emanated as an auspicious candidate as a solar cell absorber layer. In this article, we have explored the fundamental properties such as structural, electronic, optical, elastic, and thermoelectric parameters of CH3NH3PbBr3 through first‐principles calculations, because it has accomplished the entire criterion to use in photovoltaic and thermoelectric applications. We have used full‐potential linearized augmented plane wave method (FP‐LAPW) within DFT and implemented in Wien2k. The generalized gradient approximation (GGA) parameterized by Wu‐Cohen (WC) has been used to optimize the lattice parameter, while for band gap calculations different exchange‐correlation potentials (LDA/GGA) have been used. The band gap up to 2.26 eV has been achieved by doing some appropriate changes in the parameter of TB‐mBJ exchange‐correlation potential. The nature of band gap is direct and exist at R (0.5 0.5 0.5) symmetry point of the Brillouin zone. All the optical spectral response between 2 and 5 eV is due to the transition of Br 5p with little contribution Pb 5s orbital electrons of VBM to Pb 6p orbitals in CBM and a minor contribution of second band gap components also incorporate. As well as, a high absorption coefficient shows that it may be strongly applied in photovoltaic devices. The orientation of organic cations (CH3NH3)+ has no considerable impact on the band structure formation. To render a solid foundation about the application in the thermoelectric device up to the high‐temperature region, the thermoelectric parameters have been discussed at optimal carrier concentration and definite temperature range. The measurement of elastic constants, B/G and Poisson's ratio indicates the ductile nature of CH3NH3PbBr3. To the best of my knowledge, most of the investigations have been discussed first time for this material. CH3NH3PbBr3 is an auspicious candidate as a solar cell absorber layer with ductile nature. It has solid foundation about the application in the thermoelectric device up to the high‐temperature region