Phase morphology effects on the thermoelectric properties of Pb0.25Sn0.25Ge0.5Te

Seeking novel thermoelectric materials for power generation applications, the p-type Pb0.25Sn0.25Ge0.5Te composition is currently being investigated. This composition, lying in the miscibility gap of the quasi-ternary phase diagram of PbTe–GeTe–SnTe, exhibits a tendency for phase separation into fine submicron domains in addition to nearly optimized electronic properties. The maximal figure of merit, ZT, of ∼1.2 was obtained at 450 °C, showing a high thermoelectric potential. Possible routes for further enhancement of ZT up to ∼1.8, upon precise controlling of the morphological alignment of the involved phases, are described.