一种用于光电/光热综合利用的光谱选择性金属网格涂层

A SPECTRALLY SELECTIVE METAL MESH COATING FORPHOTOVOLTAIC/THERMAL APPLICATIONS

针对光电/光热综合利用(PV/T),提出一种纳米级金属(银)网格涂层,在太阳辐射波段(0.3~2.5μm)具有高透过率,在红外波段(2.5~25μm)具有高反射率,与全波段(0.3~25μm)高吸收/发射的PV/T吸收器结合可产生太阳辐射波段高吸收、红外低发射的光谱选择特性,从而显著降低PV/T的辐射热损。基于时域有限差分方法,模拟分析网格周期、宽度和厚度对金属网格涂层光谱特性的影响。结果表明:当纳米金属网格的周期为500 nm,厚度为50 nm、宽度为30 nm时,其太阳波段透过率达到0.90,红外反射率达到0.88。与已有ITO光谱选择性涂层相比,金属网格涂层的太阳辐射透过率提高20%,红外反射率提高24%,同时薄层电阻(5.3Ω/Sq)降低47%。

In this paper,a nano-scale metal(silver)grid coating was proposed for the photovoltaic/thermal applications(PV/T),it has high transmittance in the solar radiation band(0.3-2.5μm),and high reflectivity in the infrared band(2.5-25μm).When combined with PV/T absorber with high absorption/emission in the full band(0.3-25μm),it can guarantee the spectral selection characteristics of high absorptivity in solar band and low emissivity in infrared band,which can significantly reduce the radiation heat loss of PV/T.Based on the finite-difference time domain method,the effects of grid period,width and height on the spectral characteristics of metal grid coatings were simulated and analyzed.The results show that when the period of the nano-metal grid is 500nm,the height is 50 nm,and the width is 30 nm,the transmittance in the solar band reaches 0.90,and the mid-infrared reflectance reaches 0.88.Compared with the existing ITO coating,the solar radiation transmittance of the metal mesh coating is increased by 20%,the infrared reflectance is increased by 24%,and the sheet resistance(5.3Ω/Sq)is reduced by 47%.