A hopping model for activated charge transport in amorphous silicon

A variable‐range hopping model is examined for transport in a band tail. For an exponential density of states the difference of the activation energies of conductivity and thermoelectric power, ΔE, is essentially determined by the steepness of the tail. ΔE varies slowly with tempera ture and depends little on the localization length α of the wave functions and on the magnitude of the density of states. From comparison of the results with experimental data it is suggested that this model applies to activated transport in n‐type amorphous silicon.