Corrosion Behavior Analysis and Panel Properties Protection in Flexible OLEDs

Flexible organic light-emitting diodes (OLEDs) are of increasing attention to improve the flexibility of wearable and foldable displays. However, the inevitable issues like electrochemical corrosion due to high temperature-high humidity and operating state is causing serious concern. In this paper, we have discussed the electrochemical corrosion behaviors in flexible OLEDs and presented the formation mechanism systematically. The focused-ion-beam (FIB) pictures show puffy metal reaction resultant and adhesive peeling appearance, which made passageways between the two adjacent trace lines in panel and caused electric short. To address the electrochemical corrosion concern, several techniques were presented for panel properties protection, including interface adhesion improving, ultraviolet rays (UV) hard baking and passivation layer coating. It was demonstrated that the suppression of puffy metal and the elimination of adhesive peeling were obtained after high temperature-high humidity experiments. The research opens the possibility of considering more influences on reliabilities improvements in flexible OLEDs.