No abstract

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 a t 80 and 273 K. A phenomenological theory of the warm carrier conductivity for the semiconductor having two degenerate bands a t k = 0 is developed. By applying this theory to the experimental data it is shown that in p-Ge a t 80 K the warm carrier conductivity relaxation process a t microwave frequencies is strongly influenced by the hole interband repopulation effect. The values of the energy relaxation time T, are evaluated for both materials a t both temperatures. It is established that t, 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.kICCJIeAOBaHa YaCTOTHaR 3aBHCHMOCTb 3JIeKTPOIlPOBOAHOCTH TenJIbIX 3JIeHTPOHOB B n-II p-Ge B qaCTOTHOM ~a a n a a o~e

Measurements of the hot electron conductivity anisotropy in germanium are made at lattice temperatures of 78 and 290 °K. The conductivity is measured both parallel and perpendicular to the direction of the high electric field. From the data the products n(i)〈τ〉(i) are obtained for each valley for fields in the 〈110〉 and 〈111〉 crystallographical directions. The electron “temperatures” and relative populations of the valleys are calculated. The results are not in agreement with the theory of Reik and Risken applied to n‐type germanium. The experimental results are compared with the theoretical ones obtained using the electron temperature approximation.