Effect of Minority Impurities on Impurity Conduction inp-Type Germanium

Hall coefficient R and resistivity ρ of various p-type germanium samples which contained the same concentration of acceptors NA but different amounts of compensating donors ND have been measured between 300^∘{}K and 1.3^∘{}K. The process of impurity conduction at low impurity concentrations differs from that at high concentrations in that it requires the presence of empty majority centers. As in the case of n-type Ge, the two different impurity conduction processes could be distinguished by observing the change of ρ resulting from a change in the degree of compensation in the temperature range of impurity conduction. At large impurity concentrations (NA=2.4×10¹⁷/cc) the resistivity is independent of temperature only if the concentration of mobile carriers is sufficiently large. The resistivity increases with a finite activation energy in strongly compensated samples.