The Electrical Properties Dependence on the Annealing of Flashed GaAs Films

GaAs films have prepared by flash evaporation technique on glass substrate with thickness of about 1mm and substrate temperature of about 373 K under vacuum of about 10 super( -5) mbar. The prepared films have been annealed at different annealing temperatures 423, 473, 523, 573 K. The structures of GaAs films have been studied by X-Ray diffraction technique and show a polycrystalline structure of cubic phase with strong oriented at (111) direction, the annealing process enhance the structural improvement. The prepared films have two activation energies, which increased with increasing the annealing temperature. The electrical D.C. conductivity decreased with increasing the annealing temperature. Hall Effect showed that all prepared films are n-type, Hall mobility increased after annealing. The carriers concentrations decrease from 7.7910 super( 14)cm super( -3) to 310 super( 14)cm super( -3). The carrier's life times increased after annealing. The correlated barrier hopping model is the most consistent mechanism to describe the sigma ( omega ) behavior of GaAs films.