Electronic band structure of (001)--semiconductor surfaces: the frontier--induced semi--infinite--medium states.

Abstract

In previous work we have discussed the valence band electronic structure of the (001) oriented semi--infinite medium of the II--VI wide band gap zinc--blende semiconductor compounds. We have found three characteristic surface resonances besides the known bulk bands (heavy hole, light hole and spin--orbit bands). Two of these resonances correspond to the anion--terminated surface and the third one to the cation terminated surface. Furthermore, we have shown that three non dispersive (001)--surface--induced bulk states, in the $\Gamma-K$ direction of the 2D Brillouin zone, are also characteristic of these systems. To identify these states, from other known surface states, we have called them frontier--induced semi--infinite--medium states. In order to continue with the description of these systems, we review the main characteristics of the electronic structure of the (001)--surfaces and we present a detailed theoretical discussion of the frontier--induced semi--infinite--medium states. We use tight binding Hamiltonians and the well--known Surface Green's Function Matching method to calculate the electronic surface band structure.