Enhanced thermoelectric properties in Co4Sb12−xTex alloys prepared by HPHT

Abstract Skutterudite compounds Co 4 Sb 12 − x Te x with bcc crystal structure were prepared by high pressure and high temperature (HTHP) method. The study explored chemical doping with Te at the Sb site in an attempt to optimize the thermoelectric figure of merit ZT in the system Co 4 Sb 12 − x Te x . The electrical resistivities, Seebeck coefficients and thermal conductivities of the samples were measured in the temperature range of 300–710 K. We found that the presence of Te substantially decreased the electrical resistivity without any detrimental effect on the Seebeck coefficients, which improved the power factor. Among all the samples, Co 4 Sb 11.5 Te 0.5 shows the highest power factor of 35.3 µw/(cmK 2 ) at 710 K, and the maximum ZT value reaches 0.67 at 710 K.