Investigation of structural, opto-electronic, mechanical and thermoelectric properties of Rb-based fluoro-perovskites RbXF3 (X = Rh, Os, Ir) via first-principles calculations

A theoretical study on Rb-based fluorperovskites RbXF3(X = Rh, Os, Ir) is performed for the first time to explore their structural, electronic, optical and thermoelectric properties. The compounds are stable in cubic perovskite type structures with lattice spacing in the range of 4.30 4.35 Å. RbRhF3 and RbIrF3 exhibit half-metallic character with indirect band gaps of 4.2 eV and 2.1 eV, respectively, at R-Γ, whereas RbOsF3 possesses entirely semiconducting nature. The calculation of elastic properties revealed that under study compounds are mechanically stable, having ionic bonding. Furthermore, all compounds show ductile nature. Optical properties were also calculated in the broad energy range 0–40 eV.