First principle investigation of some physical properties of narrow band-gap vacancy ordered double perovskite In₂PdBr₆ (IPB) semiconductor

Results from theoretical study of structural, mechanical, thermodynamic and electronic properties of the vacancy ordered double perovskite In₂PdBr₆ (IPB) have been reported. Calculated Goldschmitd tolerance factor confirms its stability in rock-salt structured cubic phase, while formation enthalpy of the specimen ensures its thermodynamic stability. Calculated elastic stiffness constants and allied mechanical parameters of the cubic In₂PdBr₆ have predicted its mechanically stability, ductility and elastically anisotropic nature with dominance of ionic bonding and fairly high melting temperature. Study of electronic band structure and density of states have shown that the specimen In₂PdBr₆ is a direct (X-X) band-gap semiconductor with a fundamental energy band-gap of 1.29 eV. Such band-gap value is very much important regarding the absorption and detection of infrared wave by the IBP. The calculated band-gap would also project the IBP as a suitable material for infrared photovoltaic cell.