Performance analysis of three-body near-field thermophotovoltaic systems with an intermediate modulator

Abstract

Near-field thermophotovoltaic devices are attractive energy conversion systems. In the present study, three-body near-field thermophotovoltaic systems are designed by introducing an intermediate modulator between thermal emitters and photovoltaic cells. The slab/grating emitter and modulator are made from Ga-doped ZnO, while the slab/grating cell is made from gallium antimonide. The scattering matrix method is used to calculate the radiative exchange between the emitter and the cell. The performances of three-body systems of slab-slab-slab/slab-slab-grating/ grating-grating-grating are investigated. The numerical results show that the output power of the three-slab system is significantly higher than that of the corresponding two-slab system. The output power improvement is attributed to the introduction of the modulator which enables the plasmon polaritons at two GZO surfaces to be coupled. The one-dimensional grating on the surface of the photovoltaic cell can serve as an anti-reflection pattern and improve the conversion efficiency and output power of the three-body system. Grating emitters and modulators can support hyperbolic modes and enhance the radiative heat flux of the whole system. The results prove that the three-body system can provide the possibility to improve the performance of a near-field thermophotovoltaic device.