Structural and electronic properties of Bi2Se3 topological insulator thin films grown by pulsed laser deposition

We report on epitaxial growth of topological insulator Bi2Se3 thin films by Pulsed Laser Deposition (PLD) in the new UHV facility NFFA-APE at IOM-CNR and Elettra (Trieste). X-ray dffraction investigation confirms that Bi2Se3 with single (001)-orientation can be obtained on several substrates in a narrow (i.e. 20 C) range of deposition temperatures. However, onlyfilms grown on (0001)-Al2O3 substrates show an almost-unique in-plane orientation. X-ray photoemission spectroscopy reveals a slight Se deficiency (i.e. Se : Bi 1.34) as also demonstrated by the metallic bahaviour of the resistivity as a function of the temperature. In-situ spin resolved ARPES data show a single Dirac cone with a the Dirac point at 63 eV located in the center of the Brillouin zone and the spin polarization of the topological surface states. These results demonstrate that topological surface state can be obtained in PLD-grown Bi2Se3 thin films.