Graphene-based photovoltaic cells for near-field thermal energy conversion

TL;DR

This paper demonstrates that graphene-based hybrid photovoltaic cells can greatly improve near-field thermal energy conversion efficiency, enabling more effective electricity generation from waste heat sources.

Contribution

The study introduces a novel graphene-based hybrid photovoltaic cell design that enhances power output in near-field thermophotovoltaic systems.

Findings

Significant increase in power generation using graphene-based cells.

Potential for efficient waste heat energy conversion.

Enhanced near-field heat transfer due to surface polaritons.

Abstract

Thermophotovoltaic devices are energy-conversion systems generating an electric current from the thermal photons radiated by a hot body. In far field, the efficiency of these systems is limited by the thermodynamic Schockley-Queisser limit corresponding to the case where the source is a black body. On the other hand, in near field, the heat flux which can be transferred to a photovoltaic cell can be several orders of magnitude larger because of the contribution of evanescent photons. This is particularly true when the source supports surface polaritons. Unfortunately, in the infrared where these systems operate, the mismatch between the surface-mode frequency and the semiconductor gap reduces drastically the potential of this technology. Here we show that graphene-based hybrid photovoltaic cells can significantly enhance the generated power paving the way to a promising technology for an intensive production of electricity from waste heat.