Study of inorganic double perovskites Cs₂RbZI₆ (Z = Ga, In) as energy harvesting aspirant: a DFT approach

The increasing boost of clean and green energy increase the demand of double perovskites for solar cells and thermoelectric energy converters. In recent article, thermoelectric, thermodynamic, optical, and mechanical characteristics of Cs₂RbZI₆ (Z = Ga, In) are studied systematically by WIEN2K code. The problem of stability has been resolved by tolerance factor, Born criteria, and formation energy findings. The ductile nature, hardness, Navier sound velocities, Debye and melting temperature are debated thoroughly. The diverse optoelectronic and solar cells executions are recommended on the bases of direct band gaps 1.80 eV and 2.10 eV for Cs₂RbGaI₆ and Cs₂RbInI₆ in the span of visible to ultraviolet zones. The absorption bands 400–564 nm and 365–517 nm for Ga and In Based DPs covers the visible region. The losses and reflection of energy is small in the visible range. Thermoelectric proficiency is assessed in the temperature range 100–500 K by figure of merit (ZT). The ZT is approaches to unity and ultralow lattice thermal conductivity increases the importance of studied DPs for thermoelectric generators.