Alkali-metal-embedded in monolayer MoS 2 : optical properties and work functions

Embedding alkali-metal in monolayer MoS 2 has been investigated by using first principles with density functional theory. The calculation of the electronic and optical properties indicates that alkali-metal was embedded in monolayer MoS 2 appearing almost metallic behavior, and the MoS 2 layer shows clear p-type doping behavior. The covalent bonding appears between the alkali-metal atoms and defective MoS 2 . More importantly, embedding alkali-metal can increase the work function for monolayer MoS 2 . Furthermore, the absorption spectrum of monolayer MoS 2 is red shifted because of alkali metal embedding. Accordingly, this study will provide the theoretical basis for producing the alkali-metal-doped monolayer MoS 2 radiation shielding and photoelectric devices.