The Anisotropy of the Conductivity of Hot Electrons and their Temperature in Germanium

By making certain simplifying assumptions a method of analysing the anisotropy of the conductivity of electrons in germanium at high electric fields is presented. The method is applied to Koenig's data on a specimen having a free carrier concentration of 6.5 × 1014 cm-3. The electron temperatures in each valley are obtained and the mobility and population of carriers within the valleys are calculated. These electron temperatures are compared with electron temperatures calculated from an energy balance equation applied to each valley as though it existed independently of the other valleys. The comparison shows that there is interaction between electrons in different valleys. Estimates are made of the rate of energy transfer between valleys.