Amorphous films were prepared from their constituents by using the co-evaporation technique. The temperature dependence of direct-current conductivity for the as-deposited (fresh) As-rich and that of films thermally annealed at 373 to 553K was measured. Results of the characteristic electrical parameters indicated non-monotonic behavior during thermal annealing at 373 to 423K, and a monotonic one at 423 to 553K. The results of the density of structural defect states, using the space-charge-limited current model, were considered in relation to the nature and distribution of defect states regarding their dependence upon the heat treatment.

Thermal Annealing Effect on the Electrical Properties and Structural Defect Density of Non-Stoichiometric a-GaAs Films. F.A.Abdel-Wahab, M.F.Kotkata: Physica B, 2005, 368[1-4], 209-14