Lessons from the IEC Durability of Adhesion Accelerated Test Sequence
- National Laboratory of the Rockies, Golden, CO (United States)
The IEC 62788-1-1 and IEC 63209-2 standards use aging sequences for durability of adhesion in photovoltaic (PV) modules, which may be evaluated using the single cantilever beam (SCB) test. Because the encapsulant forms critical interfaces with the front glass and solar cells, degradation at those interfaces under ultraviolet (UV) exposure, elevated temperature, and humidity can lead to interfacial delamination - compromising the long-term reliability. In this work, adhesion durability of UV-transmitting poly(ethylene-co-vinyl acetate) (EVA) encapsulant to glass and to silicon solar cells is evaluated after sequenced UV and damp heat aging (85C/85%RH). Laminates were prepared using StarPhire solar front glass with thin glass or PERC cells, and two EVA formulations with different concentrations of siloxane coupling agent. Adhesion was quantified by measuring critical debond energy using the SCB method. Both formulations exhibit similar qualitative trends, while different adhesion is observed at the periphery despite the use of low-shrink manufacturing. The results show that while glass/EVA adhesion remains stable or increases after UV exposure and shows only moderate changes after damp heat, the EVA/cell interface exhibits an irreversible loss of adhesion following UV and then damp heat exposure. Although glass/EVA interfaces generally exhibit lower debond energies, the EVA/cell interface is significantly more vulnerable to UV-driven degradation, identifying it as the dominant reliability risk location through early- and intermediate-module life. These results demonstrate that accelerated aging sequences can expose large, interface-specific losses in adhesion durability and underscore the importance of interface engineering for long-term PV module reliability.
- Research Organization:
- National Laboratory of the Rockies (NLR), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
- DOE Contract Number:
- AC36-08GO28308;
- OSTI ID:
- 3027553
- Report Number(s):
- NLR/PO-5K00-98784
- Resource Type:
- Conference poster
- Conference Information:
- Presented at the PV Reliability Workshop (PVRW) 2026, 24-26 February 2026, Lakewood, CO
- Country of Publication:
- United States
- Language:
- English
Similar Records
FTIR Investigation of EVA Chemical Bonding Environment and Its Impact on Debond Energy
Materials Testing for PV Module Encapsulation
Journal Article
·
Mon Apr 01 20:00:00 EDT 2019
· IEEE Journal of Photovoltaics
·
OSTI ID:1514845
Materials Testing for PV Module Encapsulation
Conference
·
Wed Apr 30 20:00:00 EDT 2003
·
OSTI ID:15004262