Temperature dependence of the thermoelectric properties of Si doped SiC.

Abstract

Thermoelectric properties of the Si doped SiC were measured. It is intended to reduce the thermal conductivity by addition of isoelectric element Si. Measurements of electrical resistivity, thermoelectric power and thermal conductivity were made on SiC thermoelectric semiconductor as a function of both Si doping concentration (over the range of 1.0 wt.%-40.0 wt.%) and temperature (from room temperature to 750°C). Measurements of Hall coefficient, X-ray crystallography and EPMA were also made on these samples. The thermal conductivity decreases with increase of Si concentration. At Si concentration of 40.0 wt.%, minimum thermal conductivity reached to 13 W/mK. The figure of merit Z was calculated from electrical resistivity, thermoelectric power and thermal conductivity. The maximum value of the figure of merit reaches 2×10-4K-1 at 750°C and Si concentration of 40.0 wt.%.