Enviroament friendly thermoelectric

Enviroament friendly thermoelectric materials have attactedwidespread interest for potential applications in space explora-tion. exhaust recycling, and clean cooling1 The energyconversion efficiency is related to the materials intrinsic prop-erties which can be characterized by the dimensionless figure ofmerit ZT = where 7 is & absolute temperature, 5 is theSeebeck coefficient, a is the electrical coiductivity, and k is thetttennal conductivity. The three parameters S, Gt and k arecorrelated to each other. Therefore, it is difficult to optimize allpaiametcrs simultaneously. The good thermoelectric perfor-mance needs high power fector （PF,鈿）,and low thennalconductivity x. Normally, alloy semkonductofs, such as Bijltej,PbTc and SiGe14_7,1 their ZT values can exceed 1.0, and show agood practical prospects. For oxides-based theimoelectrics, theirhigh chemical and thennal stability makes them to be promisingcandidates at high temperature application. Recently, variousoxides such as CajCo^18*91, SrTiOj,,0,» ZnO11'1 and BiCu-SeO112,111 have been investigated in detail to enhance the ZTvalue.