Changes in the Density of States of Germanium on Disordering as Observed by Photoemission

Abstract

An optical density of states in amorphous Ge derived from photoemission measurements shows that the maximum in the valence-band density of states is shifted 1.5 eV to higher energy with respect to the crystalline density of states. No structure is observed in the conduction-band density of states for the amorphous material, whereas strong structure is present in the crysalline density of states. Changes observed in the optical properties of Ge on disordering can be explained using these results.