Quintuple-layer epitaxy of thin films of topological insulator Bi2Se3

Atomically smooth, single crystalline Bi2Se3 thin films were prepared on Si(111) by molecular beam epitaxy. Scanning tunneling microscopy, low-energy electron diffraction, x-ray photoelectron emission spectroscopy, and Raman spectroscopy were used to characterize the stoichiometry and crystallinity of the film. The films grow in a self-organized quintuple layer by quintuple-layer mode, and atomically smooth films can be obtained, with controllable thickness down to one quintuple layer (similar to 1 nm).