A telluride-free way to improve the performance of thermoelectric systems

Researchers report they have boosted the performance of a thermoelectric device using an approach that doesn’t require tellurium. The findings reveal a path toward more efficient and sustainable commercial applications of thermoelectric cooling based on Earth-abundant compounds. Efficient and sustainable cooling is crucial to modern living, particularly in our warming world. However, current cooling strategies require substantial energy, which can exacerbate anthropogenic climate impacts. Thermoelectric cooling is an attractive solid-state heat-pump technology that could reduce energy consumption through precise and localized cooling, particularly for high-powered electronics or computing, without the need for hazardous liquids or gasses required by vapor compression refrigeration. Currently, the only commercial thermoelectric cooling material is the bismuth telluride (Bi₂Te₃)-based alloy. However, the tellurium (Te) used in Bi₂Te₃ is a scarce element on Earth, and the material overall suffers from poor efficiency, poor cooling capability, high cost, and manufacturing difficulties, which has hindered the widespread use of thermoelectric cooling technology. Thus, there is an unmet need for thermoelectric coolers that use more efficient alternative materials. Here, Yongxin Qin and colleagues show that a relatively simple lead-selenide (PbSe)-based material can become an attractive thermoelectric cooler. By minimizing an atomic defect known as a vacancy in Lead (Pb) using a strategy the authors call grid-plainification, Qin et al. were able to closely achieve the ideal PbSe lattice within a single crystal, which had numerous effects on electron transport, thus greatly improving the material’s thermoelectric efficiency. To demonstrate their proof-of-concept, the authors developed a cooling device that outperformed many other tellurium-based thermoelectric materials in both cooling and room-temperature electrical conductivity. In a related Perspective, Navita Jakhar and Maria Ibáñz discuss the study – and limitations of the approach – in greater detail.