Ab-Initio Calculations of Structural, Optoelectronic, Thermoelectric, and Thermodynamic Properties of Mixed-Halide Perovskites RbPbBr3−xIx (x = 0 to 3): Applicable in Renewable Energy Devices

In the present research work, we have examined the variations in the structural, electronic, optical, thermoelectric, and thermodynamic properties of mixed halide perovskites, RbPbBr 3-x I x (x = 0 to 3) by utilizing the FP-LAPW approach in the WIEN2k code within the GGA-PBE for exchange-correlation functionals. The orthorhombic halides RbPbBr 3-x I x are found to exhibit direct band gap semiconducting character with band gap between 2 and 3 eV, as consensus with available experimental and theoretical results for the RbPbBr 3 and RbPbI 3 compounds. The thermal stability of these materials are confirmed by the thermodynamic results obtained by Gibbs approximations. Moreover, optical parameters for RbPbI 3 are higher than those for other halide perovskites; encouraging its use for photovoltaic applications. The thermoelectric parameters of these materials are investigated at 300, 600, and 900 K, which reveals that RbPbIBr 2 is the most efficient for thermoelectric devices among the other investigated materials.