Structural, electronic, magnetic, and optical properties of new TiXY (X = F and Cl; Y = S, Se and Te) Janus monolayers: A first-principles study

Abstract Extensive investigations have been carried out to search for new multifunctional two-dimensional (2D) materials with intriguing electronic and magnetic properties. In this paper we investigate novel Janus monolayers using first-principles calculations, which may be created by halogenation of the titanium dichalcogenide (TiCh2) single layers. We employ the full-potential linearized augmented plane wave (FP-LAPW) method to solve the self-consistent Kohn–Sham equations. The exchange–correlation potentials are described with the Wu–Cohen scheme. Our simulations assert that the TiFSe, TiClS, and TiClSe monolayers show the half-metallicity, resulting from the metallic spin-up channel and semiconductor spin-down channel. In contrast the TiFS, TiFTe, and TiClTe layers exhibit metallic nature in both spin channels. Significant magnetization with total spin magnetic moments ranging from 0.812 to 1.010 μ B may be obtained, which are produced mainly by the spin-polarization of the Ti-3d orbital. The absorption coefficient spectra suggest a wide band absorption from infrared to ultraviolet regimes, with large values of the order of 105/cm. Results obtained herein suggest that the TiXCh (X = F and Cl; Ch = S, Se and Te) may be prospective candidates for applications in nano spintronic and optoelectronic devices.