High field electronic conduction in insulators

Electronic transport processes that take place in insulators are examined in two different temperature regimes. At high temperatures, field-assisted thermal ionization is considered and previous theories are reexamined on the basis of a recently proposed model that includes the role of the internal electric field. As a low-temperature transport mechanism, electron hopping in an impurity band is examined, taking into account the formation of correlated structures due to electron-electron interactions. The theoretical analysis is compared with the experimental electrical conductivity results obtained in CdF₂-doped crystals over a wide range of applied electric fields and temperatures