DFT Approach for Improving the Electronic and Optical Properties of Kznf3 Perovskite:

This study investigates the structural, electronic and optical properties of cubic perovskite KZnF3, in its pure state and doped with copper (Cu) at a concentration of 12.5%, using the full-potential linearized augmented plane wave (FP-LAPW) method within the framework of density functional theory (DFT) which is implemented in the Wien2k code. Density-of-state (DOS) analysis reveals that doping significantly alters electronic properties, notably through the emergence of 3d-Cu impurity states near the Fermi level, resulting in a shift towards the valence band and a decrease of the band gap to 2.72 eV. Optical properties were also analyzed through dielectric functions (real and imaginary parts), absorption coefficient, optical conductivity, refractive index and reflectivity. Cu doping enhances absorption in the visible spectrum, increases electron polarization and optimizes charge carrier mobility, boosting the material's performance in optoelectronic devices. These results highlight the key role of doping in engineering perovskite properties for advanced applications, including photovoltaic technologies, optical sensors and next-generation electronic systems.