Electrical conduction in CdSe near the metal-insulator transition

Abstract

Abstract Strongly compensated samples of CdSe with 10l7–1018 cm−3 have been investi-gated. Two samples exhibit metallic and three non-metallic behaviour. The various regions of impurity-band conductivity have been identified from Hall and resistivity measurements. The density of states at the Fermi level has been estimated and compared with theory. A negative magnetoresistance has been observed in both metallic and non-metallic samples. A strongly temperature-dependent positive magnetoresistance in the variable-range-hopping regime is explained in terms of a simple extension of the Mikoshiba theory.