Perspectives of new materials research for thermoelectric applications

A possibility of increasing the thermoelectric figure-of-merit of materials has been definitely identified by the use of different fabrication techniques. Put attempt of the rf-plasma processing has been made on to improve the figure-of-merit of iron disilicides beta-FeSi2. In addition, our recent results on the skutterudites CoSb3 and its related-materials are reported The lattice thermal conductivity kappa(L) Of CoSb3 is a factor of 7 to 10 higher than that of state-of-art thermoelectric material such as Bi2Te3/Sb2Te3. This carl be lowered to some degree by mixed - valence alloying. The kappa(L) of a Ir-type Co-0.9(PdPt)(0.1)Sb-3 was 0.025W/cmK, which was one-fifths small than that of CoSb3, which led to a ZT value of 0.9 at 800K. However, there has been limited in reducing the lattice thermal conductivity by the rnixed-valence alloying. The lattice thermal conductivity is strongly affected by the Debye temperature Theta(D) of materials; therefore, the first matter to be settled may be to lower the value of Theta(D) for improving the figure-of-merit.