Low-temperature thermoelectric materials and applications

Low-temperature thermoelectric (TE) materials and devices gaining traction in the field of heat management for optical communication chips and integrated circuits, owing to their exceptional qualities such as high response speed, precise temperature control, and absence of mechanical moving parts. However, despite several decades of research on TE materials, the focus has primarily been on temperatures above 300 K, and enhancing the performance of low-temperature TE materials remains a huge challenge. With the recent emergence of competitive low-temperature TE materials, such as SnSe, α-MgAgSb, Mg3Bi2, etc., it has become imperative to extract universal strategies to improve the performance of TE materials at low temperatures. Consequently, this review aims to comprehensively summarize the working mechanisms of TE devices and uncover the common requirement of high electrical transport for TE material at low temperatures. Additionally, we introduce the fundamental theory and improvement strategies of low-temperature electrical properties. Furthermore, we overview the research progress of low-temperature thermoelectric materials and propose the potential research efforts of single crystal and polycrystal with high texture degrees to further enhance their performance.