Interpretation of the Hall coefficient, electrical resistivity and Seebeck coefficient of p-type lead telluride

Abstract

The Hall coefficient and electrical resistivity have been measured from 77 to 450°K for the carrier concentration range 4.3 × 1017 to 1.6 × 1020 cm-3. A hitherto undetected maximum in the variation of Hall coefficient with temperature due to heavy hole conduction has been observed. The results were analysed using a simple two-valence-band model and it was confirmed that the heavy mass valence band was always unoccupied at very low temperatures. From the Hall coefficient measurements, the temperature and carrier concentration dependence of Fermi energy was calculated for different temperature-dependent valence band edge separations and carrier-concentration-dependent density-of-states effective mass and mobility ratios. Best values were decided from the agreement between calculated and experimental Seebeck coefficients. The density-of-states effective mass of the light mass holes was calculated and found to explain qualitatively the low-temperature variation of Hall mobility. The variation at high temperature was explained by multi-band conduction.