Structural, Electronic, Optical, Photovoltaic, and Thermoelectric Properties of MgCu 2 F 8 by Ab initio Calculations

The growing demand for materials with tailorable electronic and optical properties has spurred interest in fluoride compounds due to their large band gaps, high transparency, and chemical stability. Here, the electronic, optical, photovoltaic, and thermoelectric properties of the MgCu 2 F 8 compound are studied using density functional theory (DFT) with the Generalized Gradient Approximation (GGA). To properly consider electron-electron interactions in Cu d-orbitals, Hubbard U corrections (GGA+SOC+U) are combined with spin-orbit coupling (SOC), providing a reliable description of the electronic structure. The investigation covers essential characteristics, namely the electronic band structure and density of states, together with optical parameters featuring the refractive index, dielectric response, and absorption spectrum, for assessing their potential for optoelectronic and photovoltaic technologies. Thermoelectric behavior has been explored through the Seebeck coefficient, electrical and thermal conductivities, as well as the unit-less figure of merit (ZT). The findings reveal that MgCu 2 F 8 possesses a moderate band gap, exhibits efficient charge carrier transport, and demonstrates intense absorption in the UV region, features that make it a promising candidate for integration into optoelectronic devices. Furthermore, its possible applicability underscores its use in waste-heat recovery and thermal regulation. Overall, the analysis provides valuable insights into the intrinsic properties of MgCu 2 F 8 and underscores its potential for use in multifunctional energy-related applications.