An explanation of high cation vacancy concentration and p-type conductivity in semiconductors containing a multivalent metal in its lowest valence state

A model is presented which features an explanation for the large deviation from stoichiometry and correspondingly high hole concentration in semiconductors containing a multivalent metal in its lowest valence state. The model is based on the assumption that cation vacancy acceptor states are associated with a band which lies below the highest filled band. The energy of vacancy formation is thereby reduced by a compensating energy, Ec, which is gained as the acceptor states are filled. Using SnTe as an example, its value of Ec is estimated. © 1965.