Stability, bonding and electronic structures of halogenated MoS2 monolayer: A first-principles study

Surface decoration is a convenient and effective way to tune the properties of two dimensional (2D) materials. Here we performed a first-principles study of the functionalization of MoS2 monolayer by halogen atoms (F, Cl, Br and I). The adsorption of halogen monomer, halogen dimer on MoS2 monolayer, and the halogenation of one side of MoS2 were studied. Halogen monomers can adsorb stably on MoS2 inducing impurity states and magnetic moment of 1.0 μB per supercell. Long range antiferromagnetic (AFM) couplings are found between halogen adatoms. Semihalogenated Cl- and Br-MoS2 can be in nonbonding or bonding state, with the nonbonding state being more energetic favorable. Semihalogenated I-MoS2 can only be in nonbonding state. Semifluorinated F-MoS2 can stabilize in bonding state with a titled configuration and large binding energy. MoS2 monolayer is transferred from a semiconductor to metal upon semifluorination.