Exploring Packaging Strategies of Nano-embedded Thermoelectric Generators

TL;DR

This paper investigates how embedding nanostructures like nanowires and nanoflakes in bulk thermoelectric generators can enhance power density, analyzing the effects of multi-modality and packing fraction on performance.

Contribution

It provides insights into optimal nano-embedding strategies, introduces the advantage factor metric, and explores the maximum effective width for improved thermoelectric generator design.

Findings

Performance degradation occurs when nanostructures become multi-moded.

Nano-embedded systems with suitable cross-sections outperform pure bulk at higher packing fractions.

The advantage factor quantifies power density enhancement at given efficiencies.

Abstract

Embedding nanostructures within a bulk matrix is an important practical approach towards the electronic engineering of high performance thermoelectric systems. For power generation applications, it ideally combines the efficiency benefit offered by low dimensional systems along with the high power output advantage offered by bulk systems. In this work, we uncover a few crucial details about how to embed nanowires and nanoflakes in a bulk matrix so that an overall advantage over pure bulk may be achieved. First and foremost, we point out that a performance degradation with respect to bulk is inevitable as the nanostructure transitions to being multi moded. It is then shown that a nano embedded system of suitable cross-section offers a power density advantage over a wide range of efficiencies at higher packing fractions, and this range gradually narrows down to the high efficiency regime, as the packing fraction is reduced. Finally, we introduce a metric - \emph{the advantage factor}, to elucidate quantitatively, the enhancement in the power density offered via nano-embedding at a given efficiency. In the end, we explore the maximum effective width of nano-embedding which serves as a reference in designing generators in the efficiency range of interest.