Transport properties of heavily doped n-type CoSb/sub 3/

The transport properties of heavily Te-doped n-type CoSb/sub 3/ polycrystalline samples have been studied. We performed measurements of the electrical conductivity, the Seebeck coefficient and the Hall coefficient. The Seebeck coefficient was compared with the calculated results. The observed temperature dependence of the Seebeck coefficient was in good agreement with the calculated result assuming two conduction bands. The values of the second band effective mass and the ratio of the carrier mobilities in their bands were estimated. From this result, it was found that the second band played an important role of the large Seebeck coefficient and therefore the large figure of merit.