| The theoretical upper limit of light energy utilization of solar thermal photovoltaic cells is very high,but the actual efficiency is very low.This is due to the mismatch between the emission spectrum of the thermal radiator and the absorption spectrum of the photovoltaic cell in the thermal photovoltaic(TPV)system,so that the radiation energy can not be completely converted into electric energy.In order to match the emission spectrum with the absorption spectrum,a filter can be added between the radiator and the PV battery to achieve high transmission at a specific band.Based on the surface plasmon resonance effect,the porous gold film(SPR),has abnormal permeability and high permeability in the infrared band,so the porous gold film is suitable for thermal photovoltaic system.The high transmission characteristics of specific bands can be achieved by adjusting the hole size and its periodic structure.In this paper,based on FDTD simulation,the effects of structural parameters such as gold film thickness,hole diameter and hole center spacing on optical properties are systematically studied,and the effects of various parameters on filtering performance are summarized:with the increase of hole center spacing,the center wavelength increases and the center wavelength transmittance decreases.With the increase of the aperture,the open area of the gold film increases,the corresponding transmission intensity increases,the transmittance of the central wavelength increases,the half-peak width increases,and the central wavelength decreases,and the thickness of the gold film has little effect on the filtering performance.The approximate range of the corresponding parameters of the required optical properties is determined.When the hole center spacing is 1000 nm,and the aperture is 600 nm,the center wavelength of the porous gold film is 1.38,the transmittance is 0.85.The purpose of this study is to provide theoretical guidance for the subsequent preparation process of gold film.Subsequently,the ordered porous gold membrane was prepared by optimizing the preparation process of porous gold membrane.It is mainly divided into the following four steps:self-assembly of polystyrene(PS)microspheres,reactive ion etching of monolayer closely packed PS spheres,hot evaporation of colloidal crystal templates and removal of residual PS by organic solvents.Eight groups of porous gold films with different structural parameters were obtained,and the effects of pore center spacing and pore diameter on the optical properties were verified.By comparing the optical properties of the samples with the simulated spectra,it is found that there is a great difference between the actual properties and the simulation,but combined with the surface morphology of the samples,it is found that the closer the surface morphology is to the ideal state,the closer it is to the simulated properties.Among them,two groups have better performance and can be used in thermal photovoltaic system.One is a round-hole gold film with a hole center spacing of 580 nm,and an aperture of 429 nm,and its central wavelength transmittance is up to 68%,which is suitable for photovoltaic cells with a band gap of 0.81-1.24 ev;the other is a porous gold film with a hole center spacing of 1000 nm,and a particle size of 489 nm,which can be used as a GaSb photovoltaic cell filter with a transmittance higher than 41%in the 1-1.8 ?m band.In order to explore the influence of the incident light angle on the filtering performance,the variable angle reflection of the porous gold film is tested.it is found that the filtering performance is not sensitive to the angle change,the peak position changes little,and the maximum reflectivity is only 10%different. |
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