Low-temperature thermal conductivity of heavily doped p-type semiconductors

A theoretical and experimental investigation of the low-temperature thermal conductivity of heavily doped p-type semiconductors has been carried out. The concentration dependence of the thermal conductivity for GaSb and Si obtained here is found to be similar to that for other heavily doped p-type semiconductors. Calculations of the thermal conductivity for various p-type semiconductors including GaSb and Si have been done by using the expression for the phonon relaxation rate obtained in the authors' previous paper (see ibid. vol.17, p.2661 (1984)). They can semiquantitatively explain the thermal conductivity of semiconductors with the large spin-orbit splitting. It is shown that the essential features of the concentration dependence of the thermal conductivity are due to the concentration dependence of the shear terms arising from a multiband structure of the valence bands and of the cut-off frequency in the hole-phonon interaction.