Chapter 25 - Molecular beam epitaxial growth and exotic electronic structure of topological insulators

Abstract

With the state-of-art molecular beam epitaxy technique, layer-by-layer growth of atomically flat topological insulator Bi 2 Te 3 , Bi 2 Se 3 and Sb 2 Te 3 thin films with few defects has been realised on Si(111), graphene and insulating substrates, respectively. The growth criteria by which high-quality intrinsic topological insulators can readily be obtained is established. By using in situ angle-resolved photoemission spectroscopy and scanning tunnelling microscopy/spectroscopy measurements, the electronic structure and surface morphology of topological insulator thin films of different thickness have be systematically studied. The electronic structure and transport property of the topological insulator films can be regulated by optimising the growth conditions and tuning the gate voltage. Molecular beam epitaxy was shown to not only provide an excellent method to prepare high-quality topological insulator materials but show possibilities of engineering their electronic and spin structures as well, which is of significant importance for potential applications of topological insulators based on well-developed semiconductor technology.