Transport Properties of Bismuth Single Crystals

Abstract

The absolute Seebeck coefficient, electrical resistivity, and thermal resistivity were simultaneously measured on pure bismuth single crystals of various orientations between approximately 80° and 300°K. Using an overlapping two-band many-valley model, numerical values for the temperature dependence and anisotropy (where appropriate) of the following parameters have been calculated: (1) the overlap energy and the Fermi energy of the electrons and of the holes, (2) the density of states effective mass of the electrons and of the holes, (3) the separate electronic and lattice thermal conductivities, (4) the actual index of thermo-electric efficiency, and (5) the hypothetical ``optimum'' index of thermoelectric efficiency. The calculated electronic thermal conductivity includes a new term due to bipolar diffusion.