Thermopower and conductivity activation energies in hydrogenated amorphous silicon

Measurements of the dark conductivity activation energy are compared to that of the thermoelectric effect measured in both open-circuit and short-circuit conditions for doped hydrogenated amorphous silicon. The activation energy of the thermopower is much less than that obtained from the conductance measurements. However, the short-circuit Seebeck-current activation energy agrees exactly with the conductivity activation energy, consistent with the difference in activation energies between conductivity and thermopower arising from long-ranged disorder at the mobility edges.