Improving the physical properties of polyolefin elastomer encapsulants by radical initiators for reliable photovoltaic modules

Polyolefin elastomer (POE) has emerged as a promising encapsulant material for crystalline silicon photovoltaic (PV) modules due to its superior moisture resistance and enhanced thermal stability compared to conventional ethylene vinyl acetate (EVA). However, its inherently low adhesion strength—particularly in bifacial crystalline silicon PV modules that demand robust glass bonding—has hindered its widespread application. In this study, a novel strategy is proposed to improve the adhesion performance of POE by incorporating a radical initiator (Luperox 101) in conjunction with a silane coupling agent (VTMS). By optimizing the initiator concentration, the formulation containing 0.2 % achieved a significant enhancement in adhesion strength (294.0 N/10 mm), surpassing commercial standards, while preserving key physical properties such as light transmittance (>90 %), elongation (>400 %), and shrinkage (<1.5 %). Thermal and structural analyses via DSC and FTIR confirmed that the material’s thermal stability and chemical integrity. The enhanced encapsulant also exhibited excellent durability under damp heat and solar simulator tests, highlighting its potential as a high-performance alternative to EVA for next-generation bifacial crystalline silicon PV modules.