A two-dimensional Sb/InS van der Waals heterostructure for electronic and optical related applications.

Stable configurations with excellent optical adsorption are crucial for photovoltaics or photocatalysis. Two-dimensional materials with intrinsic electric fields have been proposed as suitable for electric and optical devices. Here, we have performed DFT calculations on the electronic and optical properties of a bilayer Sb/InS van der Waals heterostructure, which consists of Sb and InS monolayers, by studying the band structures, charge density difference and distribution. Interestingly, the Sb/InS bilayer exhibits typical type-II band alignment character with a direct energy gap of 0.44 eV, and the electrons and holes are separated on different surfaces. Furthermore, applying an external E-field and biaxial strain is proved to be an effective way to modify the energy gap, the same as the electronic and optical properties. These theoretical predictions pave the way for high performance electronic and optical devices based on new two-dimensional van der Waals structures.