Effect of one-dimensional superlattice potentials on the band gap of two-dimensional materials

Using the tight-binding approach, we analyze the effect of a one-dimensional superlattice (1DSL) potential on the electronic structure of black phosphorene and transition metal dichalcogenides. We observe that the 1DSL potential results in a decrease of the energy band gap of the twodimensional (2D) materials. An analytical model is presented to relate the decrease in the directband gap to the different orbital characters between the valence band top and conduction band bottom of the 2D materials. The direct-to-indirect gap transition, which occurs under a 1DSL potential with an unequal barrier width, is also discussed. Published by AIP Publishing.