Controlling topological electronic structure of multifunctional MXene layer

The electric field- and charge transfer-induced topological properties of Sc₂C(OH)₂ MXene layers are reported. The system transforms from a trivial insulator to a topological insulator and to a metal. The s-pd orbitals are exchanged during the topological phase transition. The modification of the bandgap along with the transition to the topological phase reveals that Sc₂C(OH)₂ MXene is a multifunctional material. The nearly free states, which form ideal conduction channels, are responsible for the topological electronic band structures.