Effects of annealing on localized states in amorphous Ge films

Annealing behaviors of the activation energy for the electrical conduction E_σ, that for the thermoelectric power E_s, the optical gap E^opt_g, and the spin density in evaporated amorphous Ge are investigated. E_σ is independent of E_s and E^opt_g, and the rates of variation of E^opt_g and E_s with annealing temperature are connected by △E^opt_g = 2.5△E^opt_s. It is suggested that the position of the Fermi level does not change with annealing in contrast with amorphous Si, and the edge of the localized tail state shifts with annealing.