Thermoelectric properties of CVD boron carbide

Boron carbide is expected to be applied to high-temperature thermoelectric energy conversion because it shows low thermal conductivity--caused by its unique crystal structure--as well as comparatively large thermoelectric power. In the present study, thick and dense polycrystals of boron carbide with various compositions were prepared by a thermal chemical vapor deposition (CVD) method, and their thermoelectric properties were systematically measured. As a consequence, slightly different results with regard to the composition dependence of thermoelectric properties and the conduction mechanism were obtained. A significant effect of microstructure on the Seebeck coefficient of B[sub 4]C also was found.