Electronic Spectrum,kConservation, and Photoemission in Amorphous Germanium

The electronic energy spectrum of amorphous Ge is computed. Energy distributions of photoemitted electrons are determined, and the results are in excellent accord with experiment. Our analysis shows that the short-range order is primarily responsible for the observed spectral structure. Long-range disorder, however, has a strongly perturbing influence on some of the spectra. It appears that there is little difference between the valence-band density of states in the amorphous and crystalline forms, but increased disordering can cause a red shift of the ${\epsilon }_2\left(\omega \right)$ peak.