Hot Carrier Concentration in $n$-Type Germanium —a Suggested Experiment

The anisotropy character of the microwave conductivity of a many-valley semiconductor in the presence of a high dc field is discussed. The propagation of microwave signals through this anisotropic medium is briefly studied and a microwave experiment is suggested for determining the elements of the conductivity tensor. It is shown that an analysis of the data obtainable from the experiment would enable one to find out whether the $〈100〉$ valleys in $n$-type germanium are populated under hot-electron conditions. It is also shown that if the $〈100〉$ valleys are found to be insignificantly populated, one may determine the anisotropy factor $K$ and the carrier population in the different $〈111〉$ valleys from these data.