The thermal conductivity of germanium and silicon between 2 an d 300° K

Abstract

The thermal conductivity of single crystals o f pure n -type germanium and of p -type germanium containing from 10 14 to 10 19 group III impurity atoms per cm 3 has been measured from 2 to 90° K . In some cases the readings have been extended up to room temperature. Whereas the low- temperature conductivity of the pure specimens is that which one would expect from a dielectric crystal, the addition of even very amounts of group III impurity decreases the conductivity very considerably and alters its temperature dependence. It is suggested that the extra thermal resistance introduced is due to the scattering of the lattice vibrations by the electrons or holes in the impurity energy levels. The theory of such scattering has been worked out by Ziman, and the experimental results are shown to be in fair agreement with this theory. A pure n -type silicon single crystal and a gold-doped p -type silicon crystal show a behaviour similar to the germanium. The room-temperature conductivity of germanium and silicon is 0⋅64 and 1⋅45 watt units respectively.