Fundamentals and advances in transverse thermoelectrics

TL;DR

This review explores the principles, phenomena, and recent advances in transverse thermoelectrics, highlighting their potential for simplified energy harvesting and cooling applications due to their unique charge-heat current interconversion.

Contribution

It provides a comprehensive overview and unified classification of transverse thermoelectric effects, including performance formulations and recent material developments.

Findings

Transverse thermoelectric effects enable simple device structures.

Thermal boundary conditions critically influence device performance.

Recent material innovations show promising applications.

Abstract

Transverse thermoelectric effects interconvert charge and heat currents in orthogonal directions due to the breaking of either time-reversal symmetry or structural symmetry, enabling simple and versatile thermal energy harvesting and solid-state cooling/heating within single materials. In comparison to the complex module structures required for the conventional Seebeck and Peltier effects, the transverse thermoelectric effects provide the complete device structures, potentially resolving the fundamental issue of multi-module degradation of thermoelectric conversion performance. This review article provides an overview of all currently known transverse thermoelectric conversion phenomena and principles, as well as their characteristics, and reclassifies them in a unified manner. The performance of the transverse thermoelectric generator, refrigerator, and active cooler is formulated, showing that thermal boundary conditions play an essential role in discussion on their behaviors. Examples of recent application research and material development in transverse thermoelectrics are also introduced, followed by a discussion of future prospects.