Chen Zhiwei, Zhang Xinyue, Zhang Shuxian, Luo Jun, Pei Yanzhong
Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, China.
Nat Mater. 2025 Jan;24(1):34-38. doi: 10.1038/s41563-024-02039-z. Epub 2024 Oct 29.
In the 1850s, Lord Kelvin predicted the existence of a thermoelectric cooling effect inside a whole material (the Thomson effect) according to thermodynamics, in addition to the Peltier effect that enables cooling at the junction between dissimilar materials. However, the Thomson effect is usually negligible (ΔT/T < 2%) in conventional thermoelectric materials because the entropy change in charge carriers is fairly small, leading to the guiding principles for advancing thermoelectric cooling to be based on the framework of the Peltier effect and that the figure of merit ZT should be maximized to optimize performance. Here, we demonstrate a Thomson-effect-enhanced thermoelectric cooler using a large Thomson coefficient (τ) induced by the direct manipulation of charge entropy through an electronic phase transition in YbInCu. The devices achieve a steady temperature span (ΔT) of >5 K from T = 38 K. Our findings suggest not only another approach to advance thermoelectric coolers in addition to improving ZT but also technologically opens opportunities for solid-state cryogenic cooling applications.
在19世纪50年代，开尔文勋爵根据热力学预测，除了能在不同材料的交界处实现冷却的珀耳帖效应外，在整个材料内部还存在热电冷却效应（汤姆逊效应）。然而，在传统热电材料中，汤姆逊效应通常可以忽略不计（ΔT/T < 2%），因为电荷载流子的熵变相当小，这导致推进热电冷却的指导原则基于珀耳帖效应的框架，并且优值ZT应最大化以优化性能。在此，我们展示了一种利用通过YbInCu中的电子相变直接操纵电荷熵所诱导的大汤姆逊系数（τ）的汤姆逊效应增强型热电冷却器。这些器件在T = 38 K时实现了>5 K的稳定温度跨度（ΔT）。我们的研究结果不仅表明了除了提高ZT之外推进热电冷却器的另一种方法，而且在技术上为固态低温冷却应用开辟了机会。
