Model for the Electronic Transport Properties of Mixed Valency Semiconductors

Abstract
It is shown that the simple ``hopping model'' for the transport processes of mixed valency semiconductors is inadequate for impurity concentrations [similar or greaterthan]1%. In particular, it is necessary to redefine (1) the number of free charge carriers, and (2) the density of available states because of the dominant role played by the impurities in the high concentration range.