Optical properties of 2D pristine and doped Janus WSSe using first-principles study

This paper explores the electronic (optical) properties of pristine and p-type doped (boron (B), aluminum (Al), gallium (Ga)) tungsten (W), sulfur (S) and selenium (Se) (WSSe) monolayers (MLs) through first-principles calculation. The electronic properties total density of states and band gap are investigated; the results confirm that magnetic attributes are induced after doping of p-type (boron, aluminum, gallium) materials in the system. Further, the optical properties of the studied system – namely, the dielectric function (real (ϵ ₁) and imaginary (ϵ ₂)), absorption index (α) and refractive index (η) – are extracted systematically. The real part ϵ ₁ has negative values, which indicates that the material is opaque to light through that region. The imaginary part ϵ ₂ shows that the boron-doped WSSe ML has the highest light-absorbing capacity. Moreover, the absorption index shows that the peaks align in the ultraviolet (UV) range for both pristine and p-type doped systems. The refractive index (η) is investigated, and the peaks are located in the UV region. Again, the boron-doped system has the maximum value, which agrees with the reported results. Thus, it is concluded from the study of the optical properties of p-type doped systems that the boron-doped system is more suitable for designing optoelectronic devices.