Bulk nanostructured thermoelectric materials: current research and future prospects

TLDR

Thermoelectrics can convert heat to electricity, yet their low efficiency limits use to niche markets; nanostructuring has markedly improved performance, and bulk nanostructured materials—fabricable at scale and compatible with existing devices—offer the most promise for commercial deployment. This review aims to chart the first generation’s progress toward commercialization while highlighting the need for a deeper understanding of carrier transport to enable a second generation of bulk nanostructured thermoelectrics. The authors survey current principles and status, identify unresolved carrier‑transport questions, and explain how contemporary research is addressing these gaps.

Abstract

Thermoelectrics have long been recognized as a potentially transformative energy conversion technology due to their ability to convert heat directly into electricity. Despite this potential, thermoelectric devices are not in common use because of their low efficiency, and today they are only used in niche markets where reliability and simplicity are more important than performance. However, the ability to create nanostructured thermoelectric materials has led to remarkable progress in enhancing thermoelectric properties, making it plausible that thermoelectrics could start being used in new settings in the near future. Of the various types of nanostructured materials, bulk nanostructured materials have shown the most promise for commercial use because, unlike many other nanostructured materials, they can be fabricated in large quantities and in a form that is compatible with existing thermoelectric device configurations. The first generation of these materials is currently being developed for commercialization, but creating the second generation will require a fundamental understanding of carrier transport in these complex materials which is presently lacking. In this review we introduce the principles and present status of bulk nanostructured materials, then describe some of the unanswered questions about carrier transport and how current research is addressing these questions. Finally, we discuss several research directions which could lead to the next generation of bulk nanostructured materials.