Thermophotovoltaic Emitters Based on a One-Dimensional Metallic-Dielectric Multilayer Nanostructures

Abstract

In this paper, a one-dimensional multilayer is optimized for potential applications as thermophotovoltaic (TPV) selective emitter. The proposed TPV emitter was fabricated through a magnetron sputtering process by using the radio frequency (RF) magnetron sputtering system. The spectral emittance of the proposed TPV emitter is measured by using spectral transmittance and reflectance measurement system at wavelength from 0.3 μm to 2.5 μm at near-normal incident 8˚. The bidirectional reflectance distribution function BRDF is measured by three axis automated scatterometer (TAAS). The effect of the diffraction orders and plane of incidence on the spectral emittance of the proposed TPV emitter is calculated numerically by using the rigorous coupled-wave analysis (RCWA). The emittance spectrum of the proposed TPV selective emitter shows three close to unity emission peaks which are explained by the surface plasmon polariton (SPP), gap plasmon polariton (GPP) and magnetic polariton (MP) excitation. The results show that the proposed emitter has high emittance value in the spectral range of 0.69 < λ <1.97 μm and low reflectance distribution BRDF·cosθ value. It also has multi-reflection points and it works as a mirror. The measured results are in good agreement with the simulation results. The results show that the proposed TPV emitter, if used as a selective emitter with a low band gap photovoltaic cell (GaSb), would lead to high TPV overall efficiency and high electrical output power.