Investigation of non-Ohmic hopping conduction by methods of percolation theory

Abstract
Using methods of percolation theory the field dependence of the hopping conductivity is investigated. For not too high electrical fields the conductivity is shown to decrease with increasing field. This is due to segments of the first percolation paths directed oppositely to the external field. At higher fields the conductivity increases exponentially with the field. These results agree qualitatively with experimental results obtained on doped semiconductors.