2009 Volume 50 Issue 7 Pages 1582-1585
We are paying attention to extremely low thermal conductivity (κ) materials which have a potential to be next generation thermoelectric materials. Most of the extremely low κ materials that have been reported so far are ternary thallium tellurides such as Ag-Tl-Te ternary system. However, as for Tl-Te binary system, the thermoelectric properties have been scarcely reported. In the present study, the Tl-Te binary compounds, Tl2Te, Tl5Te3, TlTe, and Tl2Te3, were prepared and their thermoelectric properties were investigated. The κ of TlTe was relatively high (approximately 4 Wm−1K−1 at 300 K), while those of Tl2Te and Tl2Te3 were extremely low (∼0.5 Wm−1K−1 at 300 K). These compounds indicated relatively high thermoelectric figure of merit ZT, e.g., Tl2Te showed the highest value of 0.2 at 586 K.