Pseudo-nanostructure and trapped-hole release induce high thermoelectric performance in PbTe

Thermoelectric materials can realize direct and mutual conversion between electricity and heat. However, developing a strategy to improve high thermoelectric performance is challenging because of strongly entangled electrical and thermal transport properties. We demonstrate a case in which both pseudo-nanostructures of vacancy clusters and dynamic charge-carrier regulation of trapped-hole release have been achieved in p-type lead telluride-based materials, enabling the simultaneous regulations of phonon and charge carrier transports. We realized a peak zT value up to 2.8 at 850 kelvin and an average zT value of 1.65 at 300 to 850 kelvin. We also achieved an energy conversion efficiency of similar to 15.5% at a temperature difference of 554 kelvin in a segmented module. Our demonstration shows promise for mid-temperature thermoelectrics across a range of different applications.