Thermodynamics of Light Management in Near-Field Thermophotovoltaics
Georgia T. Papadakis, Meir Orenstein, Eli Yablonovitch, Shanhui Fan
Abstract
Thermophotovoltaic (TPV) systems hold promise for recycling heat into electricity, but a key challenge is to lower the operating temperature to the range of industrial waste heat, at high efficiency. The authors offer a thermodynamic analysis of the open-circuit voltage of TPV systems operating in the far and near fields, and compare to solar PVs. An analytic model shows that although nonradiative losses increase in the near field, luminescence efficiency improves significantly in this range. This work suggests that an ultrathin near-field TPV system can exhibit ultrahigh open circuit voltage and high efficiency, for emitter temperatures much lower than its far-field counterpart.