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The Hall coefficients R, Seebeck coefficients S, and electrical resistivities ρ of two undoped samples of p-type GaSb were measured over the temperature ranges 20–300 K for R and ρ and 40–300 K for S. The theoretical transport coefficients R, S, and ρ were fitted in a self-consistent way to the experimental data by adjusting the material parameters. The temperature range of the analysis (80–300 K) was found to be in the transition region between a multiellipsoidal valence band structure at low temperatures and a warped sphere structure at higher temperatures. The value deduced for the heavy hole conductivity effective mass was found to be about one third of the heavy hole density-of-states effective mass md1≊0.9 m0 which was used from the theory of Kolodziejczak.

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The Hall coefficient R H , Seebeck coefficient, and electrical resistivity have been measured on hot-pressed SiGe alloys (80 at.% Si) from 4 to 300 K. The alloys were doped with As, P, or As+P from 5XlO 18 to 1.75 X 10 20 cm-J • Only slight differences in transport properties with dopant type were observed. Studies of dopant solubilities were pursued, and the results suggest that the limiting electrically active As concentrations are below those of P. In the analysis of the transport data the standard treatment of ionized impurity scattering was found to be inadequate. The theory, when modified to include the energy dependence of the screening factor, gives an adequate description of our data. Hall factors were determined from RH data and dopant concentrations obtained from chemical analysis. Hall factors were also determined from analysis of the transport data and were about 20% smaller than those based on dopant concentrations deduced from chemical analysis.

The effect of the space-charge scattering mechanism on the Seebeck coefficient of n GaAs was examined in the temperature range 4–300 K. The measured Seebeck coefficient was combined with the Hall coefficient and conductivity to determine the dominant electron scattering mechanism from 100 to 300 K. Impurity-band conduction dominated at lower temperatures. The measurements were performed on highly compensated samples with electron carrier concentrations in the range 1015−1018 cm−3. The measured transport properties are compared to theoretical predictions based on polar, ionized impurity, and space-charge scattering mechanisms. Satisfactory agreement with theory is obtained if the space-charge mechanism is included in the Seebeck coefficient as well as in mobility calculations. The experimental results indicate that the space-charge mechanism can dominate at room temperature and below for highly compensated n GaAs.