First principles quantum analysis of essential physical properties of indium based stable delafossites XInO2 (X = Li, Rb) as an energy harvesting material

Abstract

The study investigates the optical properties and thermal stability of indium-based delafossites, specifically XInO₂ oxides. It found that RbInO₂ has a direct band gap at the Γ-point, while LiInO₂ has an indirect band gap. Substituting Li with Rb reduced the band gap from 3.42 eV to 1.02 eV. The study of TDOS and PDOS offers a valuable understanding of the active involvement of different atoms and their electronic state in the transitions. The dielectric function analysis showed negative ε₁(ω) above 9 eV, indicating reflective properties. The change from Li to Rb altered the absorption spectrum, revealing potential for optoelectronic applications. The study also confirmed the compounds strong thermoelectric performance at various temperatures.