Tuning Interfacial Wettability by an Organic Adhesive Layer in an Electrowetting Display Device

Abstract In electrowetting display devices, the weak bonding between the ITO electrode and the organic dielectric layer under continuous electric field and humid heat conditions easily leads to interface delamination and dielectric performance degradation, ultimately causing pixel structure damage and device failure. To improve the interface stability and long-term reliability of electrowetting display devices, two tackifiers, SurPass 3000 and AR 300-80, as organic binders are systematically investigated to enhance interfacial compatibility. By spin-coating between the ITO electrode and the HN-018 photoresist dielectric layer, the active functional groups of the binder are used to achieve chemical bonding with the ITO surface and physical anchoring with the photoresist layer, thereby optimizing the interface adhesion and wettability. This experiment comprehensively evaluates the effects of UV pretreatment and coatings with the two tackifiers on surface wettability, electrowetting driving behavior, leakage current, device capacitance, and electrode corrosion behavior under high-temperature and high-humidity aging. The results show that SurPass 3000 can optimize the ITO surface contact angle to 26.7°, reducing the initial leakage current (Iini) while maintaining excellent electrowetting performance, and effectively suppressing electrochemical corrosion. Controlling interfacial wettability through the adhesive layer is proposed to be an effective way to improve the reliability of electrowetting display devices, providing an important reference for the interface engineering design of high-performance devices.