High‐Reliability Simulation for Prediction Water Vapor Barrier Performance in Thin Film Encapsulation with Broad Application Potential

Thin film encapsulation (TFE) plays a crucial role in protecting flexible organic light‐emitting diode devices from moisture‐related degradation. This research establishes a reliable, holistic prediction model for ultralow water vapor transmission rate (WVTR) in high‐performance TFE by finite element simulation. The model accurately calculates the WVTR for single‐layer SiN x and SiON thin films across a broad range from 1 × 10 −5 to 1 × 10 −2 g m −2 day −1 . The simulated WVTR demonstrates a strong correlation with experimental results, with deviations consistently below 5 × 10 − x g m − 2 day −1 , where X represents the order of magnitude of WVTR. Benefiting from its predictive accuracy, the model is further applied to investigate the WVTR of films with varying thicknesses and under different temperature and humidity conditions, accurately capturing both numerical values and trends. Moreover, it adeptly improves the understanding of the influence of interfaces on water vapor barrier performance in multilayer structure's TFE and the distribution of water vapor within irregularly structural TFE, as revealed by simulation. This model provides highly reliable predictions of TFE performance, offering crucial guidance for the advancement of flexible device packaging and industrial production.