Low temperature hopping conduction of a-Ga5Se95−xSbx thin films

DC conductivity measurements were made on amorphous thin films of Ga5Se95−xSbx (where x=0.0, 1, 5, and 10) in the temperature range 225–375 K. The conduction in the low temperature region is found to be due to variable range hopping, while that in the high temperature region is due to thermally assisted tunneling of the carriers in the localized states near the band edge. The effect of the addition of Sb to Ga–Se is to reduce the density of states near the Fermi level. For any given composition, the density of states near the Fermi level decreases with increasing Sb concentration. These results were analyzed in terms of Davis and Mottʹs model.