First-principles study of electronic magnetic and optical properties of black phosphorene adsorbed with Ti and S

The electronic, magnetic and optical properties of phosphorene monolayer adsorbed with Ti, S and co-adsorbed with (Ti,S) atoms were studied using the density functional theory. We utilized two different approaches: Density functional tight binding (DFTB) and full potential linearized augmented plane wave (FP-LAPW) within the generalized gradient approximation (GGA) for the exchange correlation potential. We find that the three cases S, Ti and (Ti,S) adsorbed in the phosphorene monolayer materials exhibit a spin polarization moment due to the hybridization of 3p-S, 3d-Ti and 3p states of the phosphorene material. Moreover, for the case of Ti and (Ti, S) adatoms, a half metallic characteristic with 100% spin polarization at the Fermi level is present, while for S adatoms the Fermi level is located between bands. Furthermore, we show that these materials exhibit outstanding optical properties such as a high absorption and low reflectivity in the visible light range. A higher absorption and reflectivity are denoted for (Ti,S) co-adatoms phosphorene compared to pristine case. Also, we find the largest values of absorption for S adatoms phosphorene from 628 to 675 nm for zigzag direction. These materials have potential for applications in optoelectronic, photoelectric and spintronic devices.