Abinitio Study on Ti Based Mxene Materials for Solar Cell Applications

This work presents a first-principles study of the structural, electronic, and optical properties of Ti-based MXene-derived compounds TiC₀.₅Si₀.₅, TiC₀.₅Se₀.₅, and TiSi₀.₅Se₀.₅ in bulk and layered forms. Calculations were performed using the FP-LAPW method within density functional theory as implemented in WIEN2k, employing the non-spin-polarized PBE functional. Structural optimization confirms that all compounds crystallize in the stable cubic phase with space group Fm-3m (#225). Electronic band structures and density of states reveal metallic behavior with no band gap at the Fermi level. The dominant contribution near the Fermi energy arises from Ti-3d states, with significant hybridization from C-2p, Si-3p, and Se-4p orbitals. Optical properties including dielectric function, refractive index, reflectivity, and absorption coefficient indicate strong absorption in the visible region. Layered structures exhibit reduced reflectivity and anisotropic optical response, enhancing light absorption. Among the studied materials, TiC₀.₅Si₀.₅ shows a high infrared refractive index, suggesting improved light-matter interaction. These findings highlight the potential of layered Ti materials.