Recent Advances in Superlattice-Based Thermoelectrics.

Superlattices (SLs) stand out for their unique periodic structure and allow for nuanced tuning of their properties via structural designs and interface feature modification, which have gained broad attention across diverse domains. Particularly, in the thermoelectric field, encouragingly, its existence provides a novel strategy to solve the central issue in the research of thermoelectric materials, namely, the decoupling of thermal transport and electrical transport. The extra phonon scattering at the interface, coupled with charge transfer and energy filtering in the interface, makes it possess extremely low thermal transport properties and excellent electrical transport properties simultaneously. These characteristics position the superlattices as alternatives to traditional thermoelectric materials. Herein, we heavily focus on the intricate relationship between thermal transport tailoring and element selection as well as interface features in the SLs. Then, recent advances in the research of various SL-based thermoelectric material systems and their electric transport modulation mechanisms are reviewed with carefully selected examples, subsequently emphasizing their contributions to energy harvesting and refrigeration. The review culminates in summarizing the challenges and opportunities for the future development of materials, devices, and applications. Overall, this review is expected to contribute to the research and development of high-performance thermoelectric materials and expand their application areas for researchers.