Conduction phenomena in dielectrics

For consistency with the title, the coverage of this chapter is limited to those materials which are regarded as insulators. The. decision as to where to draw the line between insulators and semiconductors is necessarily quite arbitrary and, in the present case, has been made so as to include ZnS and CdS but to exclude CdSe and PbS and other materials with a smaller energy band gap. The decision to include ZnS and CdS is very important in view of the large amount of work that has been done with these materials.