Frequency Dependence of Warm Carrier Conductivity in Germanium

The frequency dependence of the warm carrier conductivity in n‐ and p‐Ge is measured in the frequency range 0.4 to 150 GHz. The experiments are carried out at 80 and 273 K. A phenomenological theory of the warm carrier conductivity for the semiconductor having two degenerate bands at k = 0 is developed. By applying this theory to the experimental data it is shown that in p‐Ge at 80 K the warm carrier conductivity relaxation process at microwave frequencies is strongly influenced by the hole interband repopulation effect. The values of the energy relaxation time τϵ are evaluated for both materials at both temperatures. It is established that τϵ in p‐Ge is isotropic and the anisotropy of the conductivity relaxation time observed is caused by the warping of the constant‐energy surfaces of heavy holes. [Russian Text Ignored].