Papers by Author: Alessandra Caboni

Abstract: We present the growth and characterization of epitaxial Graphene on the (000-1) and (11-20) planes. In both cases, the growth was carried out in a RF furnace, by implementing our technique of confined atmosphere, covering the SiC substrate with a graphitic cap during the growth. The grown material was investigated by means of AFM, SEM, Raman spectroscopy and magneto transport. Contrary to the (0001) face, in both faces (000-1) and (11-20), almost free standing Graphene monolayers of very high quality are grown. These Graphene sheet are uniform, continuous, almost strain-free and lightly doped. In both faces, Hall bars were fabricated and Shubnikov-de Haas oscillations typical of Graphene, as well as the Half Integer Quantum Hall Effect are observed.

Abstract: Epitaxial graphene growth is significantly different depending on the polarity of the 6H-SiC surface: Si- or C-face. On the Si-face, a uniform coverage of few layers on the whole sample can be obtained, but with electrical properties disturbed by the presence of a Carbon-rich buffer layer at the interface. On the contrary, on the C-face, we demonstrated that almost free-standing very large monolayers of graphene can be obtained by covering the sample with a graphitic cap during the growth.