Prediction of two dimensional topological insulators in honeycomb structure

Abstract

Band topology of strained buckled honeycomb consisted of different elements (IV, V and III-V) as well as those placed on a variety of semiconducting and insulating substrates are systematically investigated using first-principles calculations. Topological phase diagrams of these free-standing bilayers are generated to help guide the selection of suitable substrates. The insulating hexagonal-BN is identified as the best candidate substrate material for supporting nontrivial topological insulating phase of bilayer thin films. In addition, some metal induced reconstructed substrates which have the metallic bonding and are semiconducting can be used as templates to grow 2D topological insulators. Furthermore, the bonding between honeycomb structures and substrates can be realized as H-passivation to 2D TIs. This opens up new opportunities for the scientists in the field of surface science.