Thermal Conductivity of III-V Compounds at High Temperatures

The thermal conductivity of intrinsic and heavily doped InAs crystals was determined between 300 and 900°K using the diffusivity technique. The electronic contribution was computed using the measured electrical conductivity and the Seebeck coefficient. Adding 3×${10}^{19}$ donors and acceptors ${\mathrm{cm}}^{-3\mathrm{}}$ to the intrinsic InAs increases the lattice thermal resistivity appreciably. Thermal conductivity data are given also for GaAs and InP. The anharmonicity parameters $\chi$ of the III-V compounds, obtained by comparing the experimental thermal conductivities with the theoretical values of Leibfried and Schlömann for 3-phonon processes, are found to be temperature- and mass-ratio-dependent. The temperature dependence is believed to be caused by higher order processes. The correlation between the anharmonicity parameters and the mass ratios of the constituent elements of the compounds is ascribed to an effect of optical-mode scattering on the lattice thermal resistivity.