Abstract

Tetrahedraily bonded amorphous semiconductors exhibit a structure suitable for applying the so-called extended Hückel theory (EHT) to determine the electronic density of states by means of the cluster calculation. In the following, a new mathematical model based on EHT is established. The results obtained from this model have sufficient accuracy for applications and provide a useful methodology that combines adequately with the spectrum computations. Density of valence states has been obtained experimentally with monochromatized X-rays and the theoretical results obtained in this paper are in good agreement with these experiments.