Abstract

The water vapor barrier performance of laminated thin‐film encapsulations (TFEs) is crucial for ensuring the stability of flexible organic light‐emitting diode (OLED) devices. In this study, the effects of interfaces and SiON degradation on the water vapor barrier performance of TFEs consisting of SiN x and SiON by finite‐element simulation are investigated. In the results, it is illustrated that the interface can significantly hinder water vapor transmission, and the interfacial phase of SiON/SiN x is found to be more effective in impeding water vapor transmission compared to that of SiN x /SiON. The barrier property of TFEs can be weakened by SiON degradation due to oxidation under high temperature and humidity. Among the analyzed four structures, 450 nm SiN x /50 nm SiON/450 nm SiN x /50 nm SiON exhibits the best barrier performance due to strongest interface effects and minimal SiON degradation. These simulation results correlate well with experimental reliability tests, validating the simulation model's reliability. In this study, valuable insights into optimizing TFEs designs for enhanced barrier performances in flexible OLED devices are provided.