Near-field three-terminal thermoelectric heat engine

TL;DR

This paper introduces a near-field three-terminal thermoelectric heat engine utilizing quantum dots to convert heat radiation into electrical power, achieving high thermoelectric efficiency and power output by optimizing device parameters.

Contribution

It presents a novel near-field thermoelectric heat engine design with quantum dots, demonstrating enhanced thermoelectric properties and oscillatory behavior dependent on vacuum gap thickness.

Findings

Achieves large thermopower and figure-of-merit.

Shows oscillatory dependence of Seebeck coefficient on gap thickness.

Near-field radiation significantly improves power-factor and conductivities.

Abstract

We propose a near-field inelastic thermoelectric heat engine where quantum-dots are used to effectively rectify the charge flow of photo-carriers. The device converts near-field heat radiation into useful electrical power. Heat absorption and inelastic transport can be enhanced by introducing two continuous spectra separated by an energy gap. The thermoelectric transport properties of the heat engine are studied in the linear-response regime. Using a small band-gap semiconductor as the absorption material, we show that the device achieves very large thermopower and thermoelectric figure-of-merit, as well as considerable power-factor. By analyzing thermal-photo-carrier generation and conduction, we reveal that the Seebeck coefficient and the figure of merit have oscillatory dependence on the thickness of the vacuum gap. Meanwhile, the power-factor, the charge and thermal conductivity are significantly improved by near-field radiation. Conditions and guiding principles for powerful and efficient thermoelectric heat engines are discussed in details.