Encapsulant polymer blend films for bifacial heterojunction photovoltaic modules: Formulation, characterization and durability

In this work, polymer blends based on ethylene vinyl acetate (EVA) and polyolefin (PO) at different weight ratios, also in the presence of a crosslinking agent (CA) and stabilizers (STAB), were investigated as potential encapsulants for PV modules. The EVA/PO blends were processed by melt mixing and then subjected to compression moulding following industrial lamination processing conditions. The EVA/PO films were characterized by mechanical tensile tests and thermogravimetric analysis, and the obtained results highlight the beneficial effect of PO at low amounts on the mechanical behaviour and thermal resistance at high temperatures (>300°C). All EVA/PO films were subjected to UVB exposure, and the photoaging extent was monitored by FTIR and UV-visible spectroscopies. Therefore, EVA-rich blends can be considered as good candidates for PV module encapsulants, given a compromise in the behaviour before and after photoaging.