Epitaxial growth of topological insulator <b> <i>β</i> </b> -Ag2Te thin films

Abstract

We report epitaxial growth of β-Ag2Te thin films by molecular beam epitaxy. β-Ag2Te, recently identified as a topological insulator, was grown by depositing Ag on an InP substrate at room temperature, followed by Te supply at an elevated temperature. X-ray diffraction measurements and transmission electron microscopy analyses confirmed the (002) crystal orientation and the epitaxial atomic arrangement of β-Ag2Te thin films. Electrical transport measurements revealed that the β-Ag2Te thin film exhibits two-dimensional metallic conduction while the bulk remains insulating. The epitaxial β-Ag2Te thin films obtained here provide a viable platform for investigating emergent phenomena arising from surface Dirac states and for designing heterojunction-based device structures.