Thermopower of biomorphic silicon carbide

The thermopower coefficients of cubic bio-SiC, a high-porosity semiconductor with cellular pores prepared from the biocarbon template of white eucalyptus wood, and single-crystal β-SiC taken as a reference are measured in the temperature range 5–280 K. It is revealed that, in the low-temperature range, the samples are characterized by a thermopower contribution associated with the electron drag by phonons. The thermopower of the bio-SiC samples is measured both along and across the empty pore channels and is found to be anisotropic. Two models are proposed to account for the anisotropy of the thermopower in cubic bio-SiC.