Electronic Structure of Silicon-Based Nanostructures

We have developed an unifying tight-binding Hamiltonian that can account for the electronic properties of recently proposed Si-based nanostructures, namely, Si graphene-like sheets and Si nanotubes. We considered the sps and sp models up to firstand second-nearest neighbors, respectively. Our results show that the Si graphene-like sheets considered here are metals or zerogap semiconductors, and that the corresponding Si nanotubes follow the so-called Hamada’s rule [Phys. Rev. Lett. 68, 1579 1992]. Comparison to a recent ab initio calculation is made.