Preparation And Properties Of Silica Antireflection Coatings

The energy crisis and environmental pollution problems are becoming more and more serious,and it is imperative to develop green and pollution-free renewable energy.Solar energy is considered to be the most important energy source in the 21st century due to its advantages of being renewable,non-polluting and inexhaustible.In recent years,photovoltaic power generation technology based on solar energy has attracted worldwide attention.Crystalline silicon solar cells have become the leading products in the photovoltaic market due to their advantages of mature technology and easy mass production,and have shown potential application value in Building-Integrated Photovoltaics（BIPV）systems.However,crystalline silicon solar cells still face the problems of low photoelectric conversion efficiency and high cost.In this dissertation,focusing on the above key issues,based on the antireflection principle and the light conversion principle of rare earth complexes,antireflection coatings and luminescent solar concentrators with high transparency were prepared,and their effects on the photoelectric conversion efficiency of solar cells and the application of luminescent solar concentrators with high transparency as solar windows in BIPV systems were studied.（1）Acid-catalyzed silica sol（ACSS）and base-catalyzed silica sol（BCSS）were prepared by sol-gel method,and the acid-base composite catalytic sol（ACSS@BCSS）was prepared by mixing ACSS and BCSS in a volume ratio of 1:5.The anti-reflection coating with high transmittance and good mechanical stability was prepared by dip-coating method.The anti-reflection coating has excellent anti-reflection performance,and the highest transmittance in the visible light region is about 99%.Compared with the blank photovoltaic glass substrate,the transmittance can be increased by about 8%.At the same time,the anti-reflection coating has good mechanical stability.After repeatedly rubbing the coated glass with a cotton ball soaked in alcohol for 100 times,the UV transmittance of the coated glass before and after the rubbing was tested.The experimental results showed that the UV transmittance only decreased slightly（<1%）;at the same time,the UV transmittance of the coated glass was tested before and after exposure at room temperature for 80 days,and the UV transmittance almost did not decrease.The above results all prove that the anti-reflection coating has good mechanical stability.In addition,the photoelectric conversion efficiency test of solar photovoltaic modules coated with anti-reflection coating was carried out.The test results proved that the anti-reflection coating can increase the photoelectric conversion efficiency of the module by about 4%.（2）Using polymethyl methacrylate（PMMA）doped Eu（2m CND）₄Na complexes as optical waveguide materials and acrylic glass as substrates,luminescent solar concentrators with different complexes were prepared（Eu（2m CND）₄Na/PMMA@LSC）.Eu（2m CND）₄Na/PMMA@LSC exhibits excellent luminescence properties,and side-emission red light can be seen even under daylight.The Eu（2m CND）₄Na/PMMA@LSCs with different contents of complexes（0.5%,1%,2.5%,4%,5%）exhibited high transmittance（91%）in the visible region.In addition,the photoelectric conversion efficiency test was carried out on the side-coupled solar cell.When the doped Eu（2m CND）₄Na complex was 4%,the photoelectric conversion efficiency of the solar cell was 0.61%.（3）The anti-reflection coating prepared in（1）was coated on the surface of Eu（2m CND）₄Na/PMMA@LSC to construct a high-transparency solar window.The luminescence spectrum test and ultraviolet transmission spectrum test of the system prove that the antireflection coating not only does not impair the luminescence properties of Eu（2m CND）₄Na/PMMA@LSC,but also increases its transmittance by about 7%.In addition,after 35 h of UV aging test at 365 nm（～200 m W/cm²）,the luminescence intensity of the material did not change much,proving that Eu（2m CND）₄Na/PMMA@LSC has good photostability.At the same time,the photoelectric properties of the system were studied,and it was proved that although the anti-reflection coating did not affect the photoelectric conversion efficiency of solar cells,it improved the transparency of Eu（2m CND）₄Na/PMMA@LSC,making it more aesthetically pleasing as a solar window quality.The design and research of this system provides new insights for the faster realization of photovoltaic building integration.