Enhanced stability analysis of nano-SiO 2 modified ethylene vinyl acetate (EVA) laminate modules based on TOPCon solar cells

Abstract Reliable encapsulation materials are essential for ensuring the long-term stability of high-efficiency Tunnel oxide passivated contact (TOPCon) photovoltaic (PV) modules. In this work, a nano-engineered EVA (nano-EVA) encapsulant incorporating 2 wt% SiO 2 nanoparticles was developed and systematically compared with conventional EVA and Polyolefin Elastomer (POE). The SiO 2 incorporation reduced the water-vapor transmission rate to 38% of its original value, effectively suppressing moisture ingress and mitigating electrode corrosion. As a result, nano-EVA encapsulated modules exhibited only 0.65% power loss after 2000 h of damp-heat aging (85 °C/85% RH) and a potential-induced degradation (PID) efficiency loss of 0.8%, significantly lower than that of EVA and POE counterparts. Mechanical testing revealed a tensile strength of 26.3 MPa, representing an improvement of approximately 32.8% over EVA, while maintaining high adhesion and optical transparency. These results demonstrate that nano-EVA achieves a favorable balance between mechanical reinforcement, barrier performance, and light transmittance, offering a cost-effective and high-performance alternative encapsulant for next-generation TOPCon PV modules.