The conversion of heat to electricity by thermoelectric devices may play a key role in the future for energy production and utilization. However, in order to meet that role, more efficient thermoelectric materials are needed that are suitable for high-temperature applications. We show that the material system AgPb(m)SbTe(2+m) may be suitable for this purpose. With m = 10 and 18 and doped appropriately, n-type semiconductors can be produced that exhibit a high thermoelectric figure of merit material ZTmax of approximately 2.2 at 800 kelvin. In the temperature range 600 to 900 kelvin, the AgPb(m)SbTe(2+m) material is expected to outperform all reported bulk thermoelectrics, thereby earmarking it as a material system for potential use in efficient thermoelectric power generation from heat sources.

Energy conversion Energy conversion V 1650Cubic AgPb m SbTe 2+m : Bulk Thermoelectric Materials with High Figure of Merit.-The title materials with m = 10 and 18 are n-type semiconductors exhibiting a high thermoelectric figure of merit of about 2.2 at 800 K. They are expected to outperform all reported bulk thermoelectrics in the temperature range 600-900 K and to find applications in thermoelectric power generation from heat sources, such as vehicle exhaust, coal-burning installations, or electric power utilities. With a hot source of 900 K and a temperature difference of about 500 K, a conversion efficiency of more than 18% may be achieved. -(HSU, K. F.; LOO, S.; GUO, F.; CHEN, W.; DYCK, J. S.; UHER, C.; HOGAN, T.; POLYCHRONIADIS, E. K.; KANATZIDIS*, M. G.;

Thermoelectric (Peltier) heat pumps are capable of refrigerating solid or fluid objects, and unlike conventional vapor compressor systems, they can be miniaturized without loss of efficiency. More efficient thermoelectric materials need to be identified, especially for low-temperature applications in electronics and devices. The material CsBi(4)Te(6) has been synthesized and its properties have been studied. When doped appropriately, it exhibits a high thermoelectric figure of merit below room temperature (ZT(max) approximately 0.8 at 225 kelvin). At cryogenic temperatures, the thermoelectric properties of CsBi(4)Te(6) appear to match or exceed those of Bi(2-x)Sb(x)Te(3-y)Se(y) alloys.