Nonreciprocal Thermophotovoltaic Systems

Thermophotovoltaic systems, like all thermal engines, are constrained by the trade-off between efficiency and power density. Standard thermophotovoltaic systems can have efficiency approaching the Carnot limit only when the power density approaches zero. Here, we propose a nonreciprocal thermophotovoltaic system consisting of multiple nonreciprocal photovoltaic layers. With an infinite number of nonreciprocal photovoltaic layers, our engine can operate at the Carnot efficiency while generating nonzero power. Furthermore, we show that with a finite number of layers, nonreciprocal thermophotovoltaic systems can significantly outperform their reciprocal counterparts. Our work points to the opportunities of exploiting nonreciprocity in thermophotovoltaic systems.