Role of short-range order in producing an energy gap in amorphous covalent semiconductors

Abstract

The role of short-range order in determining the density of states of disordered covalent semiconductors is investigated using the multiple scattering formalism. Detailed calculations of an approximate density of states for a model consisting of clusters of carbon atoms in configurations found in amorphous and crystalline germanium are reported. These calculations suggest that the energy gap in amorphous covalent semi-conductors is a result of the short-range order.