Electron-Phonon Scattering in Te-Doped GaSb at Low Temperatures

Abstract

The reduction in the thermal conductivity of Te-doped GaSb samples at temperatures below the maximum conductivity temperature is explained in detail by considering the scattering of phonons by conduction electrons. The Ziman model has been used to fit the phonon-conductivity results on Te-doped GaSb samples with excess donor-electron concentrations in the range 1.6-1.8 \ifmmode\times\else\texttimes\fi{} ${10}^{17}$ ${\mathrm{cm}}^{\ensuremath{-}3}$, where the impurity levels merge with the conduction band. At low concentrations of the order 1.6 \ifmmode\times\else\texttimes\fi{} ${10}^{17}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ the phonons are scattered by electrons in the 000> minima band and at concentrations exceeding 1 \ifmmode\times\else\texttimes\fi{} ${10}^{18}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ the phonons are scattered by electrons in the 111> minima band. At intermediate concentrations phonons are scattered by electrons in both the bands.