Electron States and Disorder in Amorphous Ge Films Studied by Secondary-Electron Emission Spectroscopy

Structure in the secondary-electron emission spectrum of amorphous Ge films is interpreted as due to features in the density of conduction states, the magnitude of which is shown to be sensitive to disorder effects determined by substrate deposition and annealing temperatures. Activation energies for the reordering processes are determined for deposition and annealing temperatures from 20 to 500^∘{}C. The results provide evidence for density-of-states features associated with a random-network, metastable phase.