A comprehensive theoretical analysis of Cs2KGaX6 (X = Cl, Br, I): For green energy solutions

Researchers have identified double perovskites as promising materials for thermoelectric and optoelectronic technologies, owing to their versatility in energy-related applications. This research is mostly about the compounds Cs 2 KGaX 6 [X = Cl, Br, I]. It uses advanced computer programs called Wien2K and BoltzTraP to investigate their structure, electronic, optical, and thermoelectric properties. Structural analysis confirms the stability of these compounds through energy versus volume curve evaluations. The calculated band gaps for Cs 2 KGaCl 6 , Cs 2 KGaBr 6 , and Cs 2 KGaI 6 are 4.938 eV, 3.449 eV, and 2.924 eV, respectively. These values indicate that the materials can absorb light in both the visible and ultraviolet regions. The study of optical properties shows that Cs 2 KGaX 6 [X = Cl, Br, I] has strong light absorption , high electrical conductivity , interesting dielectric constants, optical reflectivity , and interesting refractive indices . These properties make it a great choice for photovoltaic uses. We meticulously evaluated the transport properties, including the Seebeck coefficient , as well as the thermal and electrical conductivities. The results highlight the strong potential of these materials for thermoelectric generators . The Cs 2 KGaX 6 [X = Cl, Br, I] compounds demonstrate exceptional properties, solidifying their viability as sustainable energy materials, particularly for photovoltaic and thermoelectric applications. • Cs2KGaX6 compounds have a cubic crystal structure in the Fm3m space group. • The atomic positions are distributed across the octahedral formed by K and Ga atoms, coordinated with Cl, Br, or I ions. • The lattice constants increase with the atomic number of X, resulting in an increase in cell volume and resistance to compression. • The bulk modulus decreases across the series from Cs2KGaCl6 to Cs2KGaI6, reflecting the increasing lattice parameter and cell volume. • The study investigates the electronic properties of Cs 2 KGaCl 6 , Cs 2 KGaBr 6 , and Cs 2 KGaI 6 using the GGA + U computational method. • The optical and dielectric properties of Cs 2 KGaX 6 compounds make them strong candidates for optoelectronic and solar applications. • The thermoelectric properties of Cs 2 KGaX 6 compounds were analyzed using Boltzmann transport theory and the BoltzTrap tool. • The combination of tunable Seebeck coefficients, electrical conductivity, and thermal conductivity indicates strong potential for use in waste heat recovery, power generation, and thermoelectric cooling systems.