Thickness optimization of the output power and effective thermoelectric figure of merit of thin thermoelectric generator

TL;DR

This paper introduces effective thermoelectric metrics that account for film size, optimizing thickness to enhance power output and efficiency in thin thermoelectric generators.

Contribution

It proposes new size-dependent figures of merit and power factors, providing a framework for optimizing thin film thermoelectric device performance.

Findings

Effective figure of merit increases with optimal thickness.

Thickness dependence studied for Bi2Te3 and PEDOT.

Optimization improves energy conversion efficiency.

Abstract

The conventional thermoelectric figure of merit and the power factor are not sufficient as a measure of thin film quality of thermoelectric materials, where the power conversion efficiency depends on the film dimensions. By considering the film size, the effective thermoelectric figure of merit and effective Seebeck coefficient are introduced to guarantee that the maximum energy conversion efficiency increases as the effective thermoelectric figure of merit increases. Similarly, the effective power factor is defined. By introducing typical material properties for Bi$_2$Te$_3$ and PEDOT, we study the thickness dependence of the effective figure of merit and the effective power factor.