PbTe-based quantum-dot thermoelectric materials with high ZT

Following the experimentally observed Seebeck coefficient enhancement in PbTe quantum wells in Pb/sub 1-x/Eu/sub x/Te/PbTe multiple-quantum-well structures which indicated the potential usefulness of low dimensionality, we have investigated the thermoelectric properties of PbSe/sub x/Te/sub 1-x//PbTe quantum-dot superlattices for possible improved thermoelectric materials. We have again found enhancements in Seebeck coefficient and thermoelectric figure of merit (ZT) relative to bulk values, which occur through the various physics and materials science phenomena associated with the quantum-dot structures. To date, we have obtained ZT values approximately double the best bulk PbTe values, with ZT as high as about 0.9 at 300 K and conservatively estimated values as high as 2.0 at higher temperatures.