The Spectral Control Properties Of Representative Microstructure And Their Application

Due to coupled effects, some new electromagnetic effect are showed in the course of interplay between electromagnetic wave and microstructure when the characteristic length of structure becomes comparable to the wavelength of electromagnetic wave, such as surface plasmon polaritons (SPPs), microcavity effect and photonic band gap (PBG) effect. Based on these electromagnetic effects, the spectral radiative properties of representative structures can be adjusted.In this research, the numerical model of thermal radiation transmission in microscale is constructed to solve the spectral control of thermal radiation problems. The effects of influencing factors on spectral radiative properties are investigated, and the numerical results can be theoretical instructions for thermal spectral control of thermophotovoltaic(TPV) system. The detailed contents are as follows:(1) Taking TM model in simplicity with no magnetic or electric loss medium as illustrations, the numerical dispersion of FDTD algorithm was analyzed. Besides, the Lorentz-Drude model of tungsten (W) and the Sellmeier dispersive equation of silicon (Si) were also constructed in this manuscript.(2) This research constructed the dispersion relation of SPPs at surface grating, and the effects of microcavity effect and PBG effect to the spectral radiative properties were discussed. Based on SPPs and microcavity effects, microstructure thermal radiators for TPV system with GaSb cell were designed. The results showed that the emissivity of complex gratings and microcavity arrays structure were higher than the emissivity of others within the response wave band of GaSb cell. Besides, a one-dimensional Si/SiO2 photonic crystal was designed based on the PBG effect, and the spectral transmittance was calculated using the FDTD algorithm.(3) The spectral control properties of microstructure were discussed to enhance the performance of solar cells by improving the light trapping. The electromagnetic energy in the solar cell with different microstructure surface was investigated. Besides, the antireflection performance of Si solar cell with tapered microstructure was also discussed.