Critical weight percent of graphene nanoplatelets (GNPs) that optimizes water barrier and transport properties of ethylene vinyl acetate (EVA) for improved photovoltaic module packaging reliability

Ethelyne Vinyl Acetate (EVA) is used to encapsulate crystalline silicon photovoltaic module, but its poor water barrier property (WBP) limits its deployment in encapsulating and edge sealing of perovskite solar cells (PSC). As composites demonstrate boost in WBP when infused with the appropriate weight percentage (wt%) nano-filler, this research improves WBP of EVA by impregnating it with graphene nanoplatelets (GNPs). This investigation delivers a chart for determining the magnitude of water vapour transmission rate (WVTR) of wt%EVA-GNP composites within the composition range of 0–14 wt%GNP at 19°C, 36°C and 50°C temperatures. Eight film samples were developed and used as test vehicles. SEM with EDX attachment, FT-IR and Raman spectroscopies were deployed to investigate the microstructural properties while ASTM E96 wet-cup method was used to study the WVTR of the vehicles. The vehicles’ mass transport properties were computed using relevant constitutive models while water ingress into them are modeled with COMSOL Multiphysics software. The water barrier properties of EVA are improved through GNP loading. Loading EVA with 8 wt%GNP at 19°C decreased its WVTR from 2.4 g m−2 day−1 to 0.37 g m−2 day−1. Increasing wt%GNP loading above 8 wt% results in a decrease in the amount of moisture accumulated in the composite but no further decrease in its WVTR. Results from FT-IR demonstrate that at about 10 wt%GNP loading, interfacial bond between GNP and EVA is maximum owing to even dispersion of GNP. Findings from Raman Spectra demonstrate that exfoliation, dispersion and interfacial adhesion are maximum in composite in the domain of 6 wt% to 10 wt% GNP infusion. Consequently, 8 wt%-EVA-GNP composite is found optimal and proposed a good composite for sealing the edges of photovoltaic module.