  The structure and electrical properties of a two-dimensional (2D) sheet of
silicon on a graphene substrate are studied using first-principles
calculations. A new corrugated rectangular structure of silicon is proposed to
be the most energetically favorable structure. The shifting of the Fermi energy
level indicates self-doping. Calculation of electron density shows a weak
coupling between the silicon layer and graphene substrate. The 2D silicon sheet
turns to be metallic and has a much higher value of transmission efficiency
(TE) than the underlying graphene substrate.
