Epitaxial growth of high mobility Bi2Se3 thin films on CdS

Abstract

We report the experiment of high quality epitaxial growth of Bi2Se3 thin films on hexagonal CdS (0001) substrates using a solid source molecular-beam epitaxy system. Layer-by-layer growth of single crystal Bi2Se3 has been observed from the first quintuple layer. The size of surface triangular terraces has exceeded 1 μm. Angle-resolved photoemission spectroscopy clearly reveals the presence of Dirac-cone-shape surface states. Magneto-transport measurements demonstrate a high Hall mobility of ∼6000 cm2/V s for the as-grown Bi2Se3 thin films at temperatures below 30 K. These characteristics of Bi2Se3 thin films promise a variety of potential applications in ultrafast, low-power dissipation devices.