Emergence Of Topological Edge States In Oxidized Alpha-In2se3 Nanosheets: Implications For Field-Effect Transistors

Interest in the coexistence of intrinsic polarization and nontrivial band topology in a single material has grown rapidly in recent years. Although some progress has been made in this regard, in many cases, oxygenation has been reported to lead to degradation of one or both properties. In this scenario, employing first-principles calculations, we demonstrate that oxygen adsorption onto the surface of the noncentrosymmetric structure of two-dimensional (2D) In2Se3 results in the coexistence of innate electronic polarization and topologically protected edge states, rendering In2Se3O a stable topological insulator with conventional and topological band gaps greater than the thermal energy at room temperature. Furthermore, the feasibility of controlling the topological phase by field-effect switching is also demonstrated.