Atomically flat thin films of topological insulator Bi2 Se 3 have been grown on double-layer graphene formed on 6H-SiC(0001) substrate by molecular beam epitaxy. By a combined study of reflection high energy electron diffraction and scanning tunneling microscopy, we identified the Se-rich condition and temperature criterion for layer-by-layer growth of epitaxial Bi2 Se3 films. The as-grown films without doping exhibit a low defect density of 1.0±0.2× 1011 /cm2, and become a bulk insulator at a thickness of ten quintuple layers, as revealed by in situ angle resolved photoemission spectroscopy measurement.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)