A wavelength selective emitter design method using hyperbolic tangent level set-based shape optimization

A wavelength selective emitter is one of the key elements of the TPV generation system. Recently, a wavelength selective emitter with periodic microstructure on the surface has attracted attention. In this study, we propose a nonparametric design method of the wavelength selective emitter, which utilizes a shape optimization technique. The proposed method provides a design example of a 1D grating wavelength selective emitter that shows near unity emissivity at target wavelength. The obtained optimal configuration utilizes two physical mechanisms for the emissivity improvement: the excitation of the surface plasmon polariton and the cavity resonance. Furthermore, by considering multiple wavelengths, the proposed method can also provide an emitter configuration which has higher wavelength selectivity performance.