FTIR Investigation of EVA Chemical Bonding Environment and Its Impact on Debond Energy

Journal Article · Tue Apr 02 00:00:00 EDT 2019 · IEEE Journal of Photovoltaics

DOI:https://doi.org/10.1109/JPHOTOV.2019.2904219· OSTI ID:1514845

Spinella, Laura ^[1]; Bosco, Nick ^[1]

---

1. National Renewable Energy Lab. (NREL), Golden, CO (United States)

The chemical makeup of ethylene vinyl acetate (EVA) interfaces in photovoltaic (PV) modules is probed via Fourier-transform infrared spectroscopy (FTIR) to determine the impact of the EVA formulation on the adhesion degradation. EVA samples laminated with glass particles are used to demonstrate the effect of damp heat exposure on the glass-EVA interface, showing that increasing silane content increases chemical stability. Delamination interfaces created in one cell modules demonstrate a high correlation between the siloxane bonding at the silicon cell-EVA interface and the debond energy. A significant decrease in debond energy after UV exposure is also shown to be due in part to decreasing siloxane bond density at the interface. However, FTIR results indicated contributions to the adhesion beyond the chemical interface, and a basic tensile test indicates increasing bulk mechanical properties with increasing silane. These results demonstrate the importance of the EVA formulation on its adhesion performance and long-term reliability. Furthermore, it is shown that FTIR is a capable technique for assessing and quantifying chemical mechanisms within PV modules. These results can then be used to more effectively model module lifetimes and to better design polymer systems for PV modules.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 1514845
• Report Number(s): NREL/JA--5K00-72531
• Journal Information: IEEE Journal of Photovoltaics, Journal Name: IEEE Journal of Photovoltaics Journal Issue: 3 Vol. 9; ISSN 2156-3381
• Publisher: IEEE
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
Fourier-transform infrared spectroscopy
adhesion
degradation
delamination
encapsulant
reliability