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Engineering PbTe on the panoscale making it exceptionally efficient at turning waste heat into electricity © Mercouri KanatzidisResearchers in the US claim to have passed a new milestone in thermoelectrics with a material that converts heat to electricity more efficiently than ever before. The new thermoelectric material, which employs ‘panoscale’ structuring to scatter phonons, has a figure of merit (FoM) some 20% better than previously achieved.Thermoelectrics convert heat to electricity and can, therefore, ‘harvest’ waste heat from the environment. When one end of a thermoelectric material is heated, electrons flow to the cooler side, creating a voltage across the material...

Enlarge Image Energized. Spiking a conventional thermoelectric material with sodium and selenium creates regions in the crystal that conduct electricity more readily (blue and gold), boosting the material's performance. Credit: Adapted from Y. Pei et al., Nature, 473 (5 May, 2011) Engineers have come up with a handful of uses for computer chip-like devices that chill objects when plugged in or convert waste heat into electrical power—stuff like car seats that cool drivers on hot days and coolers that chill drinks when plugged in. But by-and-large, these devices, known as thermoelectrics, have remained too inefficient to make much of...