Effect of Impurity-Core on Carrier Mobility in Heavily Doped Germanium

The effect of the impurity core on the mobility of charge carriers in heavily doped Ge is investigated analyzing the role the core plays in the process of ionized impurity scattering. It is concluded, in agreement with experiments, that at the same doping level the electron mobility in an Sb-doped Ge crystal should be larger than in an As-doped Ge crystal. The dependence of the mobility ratio on the electron concentration is also investigated and found to be due to changes in the screening of the impurity ions.