Effect of Weight Percent Graphene on Barrier Properties of Ethelyne Vinyl Acetate (EVA) for Improved Photovoltaic Module Packaging Reliability

As the use of appropriate weight percent (wt%) filler in composites is critical in achieving optimal barrier properties, this research develops graphical model for predicting the right wt% graphene (GNP) filler in Ethelyne Vinyl Acetate (EVA) matrix to achieve its optimal water vapour transmission rate (WVTR). Laboratory test vehicles are four 0.16 mm thick films of EVA-GNP composites of composition 0wt%GNP, 4wt%GNP, 8wt%GNP and 12wt%GNP in EVA matrix. ASTM E96 wet-cup method is used to study composites’ WVTR. FEA tool is COMSOL Multiphysics software. Modelled geometry is Glass-xwt%GNP-Glass perovskite cell of dimensions 26 x 26 x 0.1 mm thick. The amount of wt%GNP in EVA-GNP composite and ambient temperature are found to influence its barrier properties. Increasing temperature increases composites’ diffusivity, permeability, porosity and WVTR, but increase in wt%GNP causes the diffusivity, permeability, porosity and WVTR to decrease to a minimum at 8wt%GNP and increase afterwards. Conversely, increasing wt%GNP and temperature decrease composite’s solubility. Although 8wt%GNP composite has the lowest steady state WVTR, the 12wt%GNP composite accumulates the lowest moisture concentration of magnitude 6.03 kg/m3 . It is concluded that increasing wt%GNP in EVA-GNP composite above critical 8wt%GNP results in decrease in moisture accumulation but not further decrease in WVTR.