SPLTRAK Abstract Submission
The Effect of Moisture Ingress on Titania Antireflection Coatings in Field-aged Photovoltaic Modules
Oscar Kwame Segbefia, Naureen Akhtar, Tor Oskar Sætre
University of Agder, Department of Engineering Sciences, Grimstad, Norway

Titanium dioxide (TiO2) or titania antireflection coating (ARC) enhances photovoltaic (PV) module efficiency. ARC improves the fraction of incident light reflection and coupling of the absorbed photon within the PV module. However, degraded TiO2 can affect the performance reliability of PV modules. Moisture ingress can strongly influence the refractive index, scattering properties, and extinction coefficient of the TiO2 ARC. Yet, we have not found any publication on the effect of moisture on the TiO2 ARC in PV modules in the field. In the present work, the effect of moisture ingress on the degradation of TiO2 ARC in a field-aged multi-crystalline silicon PV module is investigated. Degradation of the TiO2 ARC was observed in the scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses. Disintegration of the TiO2 nanoparticles (NPs) was also observed. The assumed Ti-O stoichiometry of the degraded TiO2 ARC in the field-aged PV module was found to be higher than 1:2. It turned out that moisture ingress strongly influences the surface morphology and defects, crystallinity, and stoichiometry of TiO2 ARC in PV modules during field operation. These degradation mechanisms affect the optoelectrical properties of the TiO2 ARC in the PV modules.