Tuning of electronic bandgap and electronic transport properties of double perovksites A2NaScI6(A = Rb, Cs) for energy device applications


 Non-toxicity, ecosystem stability, and distinct performance are the reasons to make halide-based perovskites suitable for solar cells and thermoelectric applications. This paper studied elastic properties and structural stability of cubic phase A2NaScI6 (A = Rb, Cs) by Born stability criteria and tolerance factor. Moreover, we report a comprehensive examination of these materials' elastic electronics, optical and transport behavior. The bandgap range 2.80-2.70 eV is discerned in the electronic band structure and contributes to opto-electronic devices. Maximum absorption is observed in the visible region, and bandgap is reduced by changing cations from Rb to Cs. The dielectric constants and other optical parameters are used to reveal the optical properties of A2NaScI6 (A = Rb, Cs). In the last, the BoltzTrap code is used to calculate thermoelectric characteristics. The calculated value of the figure of merit intimates that the analyzed compounds are suitable for thermoelectric applications.