Photovoltaic anti-reflection glass refers to coated glass
Coated glass is to coat one or more layers of metal, alloy or metal compound film on the surface of the glass to change the optical properties of the glass to meet certain specific requirements.
In order to reduce the reflection loss on the surface of the photovoltaic module after packaging and improve the conversion efficiency, an anti-reflection film can be prepared on the surface of the panel glass, as shown in Figure 1. This layer of anti-reflection film can be a single-layer film or a multilayer film. The single-layer film is relatively simple, but the anti-reflection effect is general, while the multi-layer film can achieve a better anti-reflection effect in a wider spectral region. The principle is that when the thickness of the anti-reflective coating is 1/4 of a certain wavelength, the two beams of light incident on the surface of the panel glass interfere with each other to cancel out the reflected light and achieve the anti-reflective effect. The reflection mechanism of light on the anti-reflection film is shown in Figure 2.
The porous SiO2 film has become an ideal material for the anti-reflection film of photovoltaic modules due to its high light transmittance and high thermal resistance. The commonly used coating methods include magnetron sputtering, chemical vapor deposition, physical vapor deposition, sol-gel and so on. Magnetron sputtering and vapor deposition methods use expensive equipment, high production costs, and are not suitable for large and large deposition coatings. The anti-reflective coating photovoltaic glass is mainly produced by the sol-gel method. The method has simple production process, low equipment price, and film refractive index can be adjusted in the range of 1.15 to 1.45, which is very suitable for industrial production. Porous SiO2, anti-reflection film is shown in Figure 3. In addition, MgF2, TiO2, Al2O3, ZrO2 and other thin films are also often used in solar glass anti-reflection film.
Although the anti-reflection coating can effectively improve the conversion efficiency of photovoltaic modules, since the use time of anti-reflection coated glass in the photovoltaic industry is relatively short, there are still fewer studies on its reliability. Therefore, the anti-reflection coated glass has been used for a period of time There will be a decrease in light transmittance and rainbow markings on the surface. How to avoid the failure of the anti-reflection film and prolong its service life is an important research topic for the development of photovoltaic modules in the future.