Antireflection (AR) coatings on photovoltaic glass with high transparency and long-term durability are highly desired not only for conventional crystalline silicon modules, but also thin-film modules. Researchers at the Ningbo Institute of Industrial Technology, the Chinese Academy of Sciences (CNITECH, CAS) have made continuous progress in developing such AR coatings.
The establishment of the 1st generation AR coating technologies dates back to 2008. In essence, these AR coatings were single-layered porous silica thin films (Chinese Journal of Materials Research 24, 478-482 (2010)). To further improve the durability, the 2nd generation AR coatings were invented. These 2nd generation AR coatings consisted of two-layered non-porous thin-films, which were very stable under extreme environments with certain improvement of transparency (Journal of Applied Physics 112, 093517 (2012), Solar Energy 89, 134-142 (2013)). Yet this double-layered structure introduced many difficulties in industrial production compared with the single layer structure.
To make single-layered AR coatings highly transparent and long-term durable, the 3rd generation AR coatings were developed. These novel AR coatings feature hollow nanostructures. That is to say, the pores in thin films were sealed by SiO2 shells. We turned the open pores of the 1st generation coatings into the closed pores of the 3rd generation coatings, which reduced the possibility of glass exposure to external aqueous attack. Although the form of pores was changed, the porosity was still well preserved, which resulted in a low refractive index and high transparency. Further details can be found in ACS Applied Materials & Interfaces 6, 1415-1423 (2014).
Three generations of AR coatings for photovoltaic applications
The 3rd generation AR coatings exhibit high transmittance which is close to the theoretical limit. Such novel AR coatings have hollow nanostructures and their surfaces are antifogging.
Prof. Weijie Song weijiesong@nimte.ac.cn
Research Group Url: http://english.nimte.cas.cn/rh/rd/newenergy/stfsc/stfsc_research_fields/
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