Exploring the Structural, Thermodynamic, Optoelectronic, and Mechanical Properties of Nitrogen‐Based Oxohalide Semiconductors for Solar Energy Devices

ABSTRACT Multifunctional properties of nitrogen‐based oxohalide KNOX 2 (X = Br, Cl, and F) compounds are investigated by using GGA‐PBE functional in (Density Functional Theory) DFT. X‐ray diffraction (XRD) analysis reveals that for each compound there exists a characteristic peak at 38.45°, confirming the orthorhombic structure with space group Pnma. According to the obtained results, the electronic band structures of KNOX 2 (X = Br, Cl, and F) compounds indicate semiconductor behavior with indirect bandgaps of 1.507, 2.158, and 3.225 eV respectively, which are convenient for optoelectronic devices. Optical properties of materials are computed and discussed in terms of photon energy in order to comprehend the connection between light and its interaction with matter. Optical topologies predict high absorption, dielectric function and refractive index values in the visible and near ultraviolet (UV) regions indicating that these materials are good for solar energy applications. Furthermore, thermodynamic properties are explored by (Density Functional Perturbation Theory) DFPT method and the zero point energies of compounds are 0.9589, 0.9841, and 1.4478 eV, respectively. The change in zero‐point energies demonstrates that atomic interactions and bond strengths are quite susceptible for all compounds. Mechanical characteristics exhibit anisotropic behavior in XY , YZ , and XZ planes. The mechanical characteristics (B/G >1.75) demonstrate their ductility and suitability for next‐generation photovoltaic solar cell applications.