Doping Strategies for Monolayer MoS₂ via Surface Adsorption: A Systematic Study

Using density functional theory calculations, we have systematically explored the effect of surface adsorption of different atoms on the electronic properties of monolayer molybdenum disulfide (MoS 2 ). We have chosen a few representative members from each group in the periodic table, ranging from alkali metals (group I) to halogens (group VII), and calculated the electronic band structure of the adatom–MoS 2 system for the most energetically stable location of the adatom adsorbed on MoS 2 . The calculated value of charge transfer from the adsorbed adatom to MoS 2 and resultant shifting of the Fermi level to the conduction band suggest that the group I (Li, Na, K) and group II metals (Mg, Ca) are the most effective adatoms to enhance the n-type mobile carrier density in MoS 2 . Our calculation is in good agreement with the experimental observation for K [ Nano Lett. 2013, 13, 1991].