Opto-electronic and magnetic properties of light transition metal elements doped buckled monolayer LiF: A systematic DFT and MD study

Adopting first-principles density functional theory (FPS-DFT) and molecular dynamics (MD), calculations on 3d transition metal (TM) doped buckled Lithium Fluoride (LiF) monolayer are performed to modify its structural, opto-electronic and spintronic properties. Through negative binding energy (E_b) and MD calculations, it can be postulated that 3d TM atom doping in LiF is a thermodynamically stable. 3d TM dopants can be considered as donor and accepter impurities depending upon 3d TM atom doped in the lattice, as in band structure diagrams energy bands appear either above the valence band or just below the conduction band. Almost all 3d TM atoms generate magnetic moments in range of ∼1.00 μ_B–∼5.00 μ_B except Cu in non-magnetic buckled monolayer LiF. Through band structure and density of states (DOS) calculations, it can be stated that, 3d TM atom doping produces a Fermi surface into a wide band gap (∼7 eV) insulating LiF material, since most of dopants induced straight impurity bands at or nearby the Fermi energy level. From optical properties perspective, blue shift is obtained in absorption and extinction coefficient parameters after 3d TM atom doping in buckled monolayer LiF. Similarly, reflectivity parameter is also enhanced in lower energy range.