Solid-state cooling: thermoelectrics

The growing demand of thermal management in various fields such as miniaturized 5G chips has motivated researchers to develop new and high-performance solid-state refrigeration technologies, typically including multicaloric and thermoelectric (TE) cooling. Among them, TE cooling has attracted huge attention owing to its advantages of rapid response, large cooling temperature difference, high stability, and tunable device size. Bi 2 Te 3 -based alloys have long been the only commercialized TE cooling materials, while novel systems SnSe and Mg 3 (Bi,Sb) 2 have recently been discovered as potential candidates. However, challenges and problems still require to be summarized and further resolved for realizing better cooling performance. In this review, we systematically investigate TE cooling from its internal mechanism, crucial parameters, to device design and applications. Furthermore, we summarize the current optimization strategies for existing TE cooling materials, and finally provide some personal prospects especially the material-planification concept on future research on establishing better TE cooling. This review systematically elucidates the thermoelectric cooling technology, and proposes a strategy for boosting the power factor by improving carrier mobility through utilizing the material-planification concept.