Preparation And Properties Of Self-cleaning Anti-reflective Film

With the increasingly serious energy and environmental problems,solar energy,as a clean energy,has been widely used.Solar panels are the most direct way to use solar energy.However,when light hits the solar cell panel,about 8%of the sunlight is reflected,which will reduce the conversion efficiency of the solar cell.Therefore,it is very important to design a film that can reduce the reflection of light on the glass surface,and a film with such a function is often called an anti-reflection film.SiO2 is a common low refractive index material,and has good optical properties and stable chemical properties,so it is often used to prepare anti-reflection films.TiO2 has good photocatalytic properties and photo-induced super-hydrophilicity for thin film materials,so it is widely used as a self-cleaning material.For outdoor applications,the anti-reflection effect is greatly reduced due to the adsorption of organic pollutants such as dust.Therefore,the preparation of an anti-reflection film with a self-cleaning function has a wide range of application values.Based on the above considerations,low refractive index SiO2 and high refractive index TiO2 with self-cleaning property were mixed to prepare anti-reflection thin films with self-cleaning function.The specific researches of our work are as fellow:(1)Through numerical simulation,we have studied the influence of the refractive index and thickness of the film on the transmittance,and obtained the film parameters that can be achieved in the experiment.(2)SiO2-TiO2 mixed sol and SiO2-TiO2-PEG mixed sol was prepared by sol-gel method.The effects of TiO2 content,PEG(polyethylene glycol)molecular weight and content on the optical and self-cleaning properties of SiO2-TiO2 and SiO2-TiO2-PEG single layer antireflection coatings were studied.(3)In order to improve the transmittance,SiO2-TiO2/SiO2-TiO2-PEG double-layer antireflective film with antireflective and self-cleaning properties was prepared with the above-mentioned sol under the best experimental conditions obtained during the preparation of a single-layer anti-reflection film.Its peak transmittance is up to 99%,the average transmittance in the visible light range is 97.5%,and it can maintain the self-cleaning performance for a long time.