▎ 摘　　要

We study how the electronic structure of the Sb(2)T(e)3 thin films on graphene changes with intrinsic defects and substrate transfer doping using first-principles calculations. We find that for freestanding Sb2Te3 thin films without defects band gap decreases with increasing film thickness, and that the behavior of three-dimensional topological insulators does not appear up to seven quintuple layers. The orbital degeneracy is broken by defects and substrate transfer doping, leading to the Rashba effect and a reduced band gap. By decreasing the defect ratio of Sb vacancies (VSb) as the primary source of p-type conductivity and increasing that of Te-on-Sb antisites (TeSb) as the primary source of n-type conductivity, coupled with a transfer doping using a graphene substrate, the energy band of Sb2Te3 thin films can be tuned from the p-type to the n-type. Differences in the local defects of Sb(2)T(e)3 can result in