Lead-Free Double Halide Perovskite Compounds: Unveiling the Structural, Optoelectronic, and Transport Properties of A2TlRhF6 (A = K, Rb) for Robust and Sustainable Green Energy Applications

The structural, optoelectronic, and thermoelectric features of A₂TlRhF₆ (A = K, Rb) have been computed using the most versatile DFT-dependent FP-LAPW method. The calculated structural parameters, including formation energy, tolerance factor, and energy versus optimized volume plots, provide clear evidence of the structural and thermodynamic stability of the studied compounds. The results of band structure and density of states (DOS) reveal that studied compounds are semiconducting materials. The energy band gap of 2.98 eV and 2.97 eV has been found for K₂TlRhF₆ and Rb₂TlRhF₆ respectively. The optical properties of the compounds are studied with incident photon energy. The maximum absorption and minimum reflectivity and loss explore its effective application in optical devices. The compounds absorption in the UV-visible range makes them ideal candidates for solar cells. In addition, transport properties are examined in detail, demonstrating significant dependence on temperature and chemical potential as demonstrated by the assessed thermoelectric parameters. In order to evaluate the transport features versus the chemical potential and temperature, the power factor (PF), thermal conductivity, figure of merit, electrical conductivity, and Seebeck coefficient are computed. Our outcomes can be useful for future experimental studies to evaluate A₂TlRhF₆ (A = K, Rb) for applications involving energy from renewable sources.