Halogenated monolayer SnS: a first-principles studies

The electronic and structural properties of a halogenated monolayer SnS is investigated by using first-principles calculations. The preferred adsorption sites for F, Cl and Br are found to be on top of the Sn atom while I atom prefers to adsorb on top of the SnS ring. All the halogenated monolayers SnS exhibit metallic behavior with charge transfer from the monolayer SnS to the halogen adatom. In the relaxed system, a larger halogen atom is located further away from the monolayer SnS which results in smaller charger transfer and thus weaker binding energy. Compared to the pristine monolayer SnS, the work function of the F, Cl or Br functionalized monolayer SnS is increased by 22 %, while for the case of I adsorption, the work function is further increased by 30%.