Plasma etched PMMA/CaF₂ anti-reflection coating for light weight PV module

Polymethylmethacrylate (PMMA) is an ideal replacement of glass where impact of weight is a serious issue. PMMA surface can be modified to make it highly transparent substrate. PMMA substrate was etched using a plasma etching system with oxygen plasma. CaF₂ was deposited on to the etched PMMA via vacuum thermal evaporation to create anti-reflection coating. The effects of the treated PMMA were analysed using different characterisation techniques. An average increase in transmittance of approximately 4% was observed on 50 W RF power treated PMMA, compared to untreated PMMA in the broadband spectrum of 400–1100 nm. An enhancement in short circuit current from 36.71 to 37.62 mA/cm² and an increase in efficiency of 2.35% was achieved when the treated PMMA was placed on a solar cell as a front cover sheet to model a lightweight photovoltaic module. These findings indicate the possibility of improving the surface morphology, optical and electrical characteristics of PMMA via treatment for photovoltaic applications.