Tuning the electronic properties of molybdenum di-sulphide monolayers via doping using first-principles calculations


 In 2D semiconductors, doping offers an effective approach for modulating their structural and electronic properties-owing to the creation of newly formed chemical bonds and bond relaxation. By means of density functional theory (DFT), we systematically explored the electronic properties of monolayer MoS2 doped with X-atoms (X comprises of metals Li, Be, Al; metalloids B, Si; non-metals (NMs) C, N, P, O and the NM atoms belonging to halogen group (F, Cl)). The bonding nature of the host structures with the doped elements have been determined using electron localization function (ELF). Phonon spectra calculations are performed to distinguish between the dynamically stable and unstable systems. The band gap of MoS2 stands divided into smaller values in a variety of magnitude depending on the dopant site and the nature of the substituted atom. The results show that halogen non-metals exhibit n-type conduction in both the (Mo- and S-rich) environments. Thus, substitutional doping of impurity atoms belonging to different groups can successfully tune the band gap of MoS2 to the desired level for its useful applications in semiconducting electronic devices in addition to other interesting information on the nature of doping, which could be adopted to dope other 2D-TMDs to tailor their electronic and optical characteristics for more efficient electronic devices.