PVDF-Based Solution for Use as a Dielectric Layer in Backsheet Crackings

Backsheet cracking is a critical reliability issue in photovoltaic (PV) modules, often leading to leakage currents and module failure. This study presents the development and characterization of a PVDF-based fluoropolymer solution designed to act as a dielectric repair layer for damaged backsheets. Various formulations using N-Methyl-2-pyrrolidone (NMP) as the main solvent and acetone or diethyl ether as cosolvents were prepared and evaluated. The most promising formulation (PVDF:NMP:Ac = 21.5:48.7:29.7 wt%) demonstrated good stability, adhesion, and ease of application. Morphological analysis revealed a porous structure with embedded air bubbles and gaps ranging from 20 μm up to several millimeters. Initial electrical insulation tests showed resistance values exceeding 100 MΩ. However, due to the material’s porosity, localized dielectric breakdown occurred under high-voltage stress tests. To enhance performance, several strategies are proposed, such as multilayer deposition, the incorporation of hydrophobic additives, and the application of superhydrophobic protective topcoats. This approach offers a practical, field-deployable method for extending the service life of PV modules affected by backsheet degradation.