P‐183: The Barrier Problem in Flexible OLED Display: A Modeling Approach

One of the major challenges in the development of flexible OLED display is the protection of the OLED materials from damage by ambient moisture and oxygen. This requires the use of polymeric substrates with exceedingly low levels of moisture and oxygen permeabilities. This problem is typically addressed through the use of multi‐layer barrier coatings comprising alternating organic/inorganic layers, an approach developed and promoted by Vitex Corp. The multi‐layer approach is critically examined through a numerical model based on a defect‐dominated diffusion process combined with experiments involving face‐to‐face lamination of two barrier films. The modeling results identify two regimes that correspond to two distinct permeation mechanisms, and provide general scaling relationships and design criteria for producing multi‐layered coatings with superior barrier performance. The results suggest that the most significant gain in barrier performance can be realized when the thickness of the organic/adhesive layer(s) is less than the average pinhole (defect) size in the inorganic barrier layer(s).