Metasurface absorber enhanced thermoelectric conversion

TL;DR

This paper demonstrates that metasurfaces significantly improve photo-thermoelectric conversion efficiency by enhancing thermal energy collection and heat conduction, outperforming traditional materials like carbon black.

Contribution

It reveals the critical role of metasurface optical thickness and structure in boosting thermoelectric performance, a novel insight for device design.

Findings

Metasurface-attached thermoelectric devices generate higher voltages than black carbon-coated electrodes.

Metasurfaces enhance thermal conductance and energy collection in thermoelectric applications.

Traditional materials like carbon black show lower performance despite higher infrared absorption.

Abstract

Metasurfaces are artificial thin materials that achieve optical thickness through thin geometrical structure. This feature of metasurfaces results in unprecedented benefits for enhancing the performance of optoelectronic devices. In this study, we report that this metasurface feature is also essential to drive photo-thermoelectric conversion, which requires the accumulation of thermal energy and effective heat conduction. For example, a metasurface-attached thermoelectric device placed in an environment with uniform thermal radiation generates an output voltage by gathering the thermal energies existing in the environment and creating an additional thermal gradient across the thermoelectric element. In contrast, when a 100-um-thick-carbon-black-coated electrode was used instead of the metasurface, the device showed low-er thermoelectric performance than that of the metasurface-attached device although carbon black exhibits higher infrared absorption than the metasurface. These results indicate that metasurface characteristics of optical thickness and thin geometrical structure for achieving the high thermal conductance are essential in enhancing the performance of photo-thermoelectric devices in terms of the effective collection of thermal energies and conduction of local heating.