Electric field modulation of the band gap, dielectric constant and polarizability in SnS atomically thin layers

• The band gap of SnS film can be tuned effectively by electric field.
• Electric field can induce a phase transition from semiconductor to semi-metal for multilayer SnS films.
• We found SnS film is more sensitive to electric field than many transition metal dichalcogenides.

The band structure and dielectric properties of multilayer SnS films have been investigated by density-functional theory total-energy calculations. It shows that electric field can tune the band gap of SnS multilayer and induce a phase transition from semiconductor to semi-metal. The critical electric field of phase transition for SnS bilayer is 0.09 V/Å, which is lower than MoS2(0.3 V/Å), MoSe2(0.25 V/Å), MoTe2(0.2 V/Å), WS2(0.27 V/Å) and WSe2(0.20 V/Å). Combining the electric structure with dielectric properties, we explain the reason why multilayer SnS films are more sensitive to the electric field. The sensitive response character to electric field makes SnS multilayer as a potential material for the nano-electronic and nano-optical devices.