Large‐Area Flexible Thin Film Encapsulation with High Barrier and Super‐Hydrophobic Property

Abstract With the development of optoelectronic devices toward miniaturization, flexibility, and large‐scale integration, conventional submillimeter rigid encapsulation techniques rarely achieve conformational functionality while blocking water and oxygen. At the same time, the sensitivity of electronic devices with organic/metal/semiconductor components to humidity and oxygen severely impairs their operational stability and lifetime. Here, a nanometer to micrometer scale organic/inorganic hybrid thin film encapsulation (TFE) with the self‐cleaning ability for flexible encapsulation is developed. The water vapor transmittance rate of polyethylene terephthalate substrate coated with the TFE is as low as 1.65 × 10−4 g m−2 day−1, and the barrier improvement factor reaches 104 at 38 °C and 90% relative humidity. This value is equivalent to 9.81 × 10−6 g m−2 day−1 at ambient conditions, sufficient to improve the lifetime of water‐sensitive electronic devices. Meanwhile, this TFE shows a super‐hydrophobic performance, with a water contact angle of 168.4°. In addition, the resulting barrier films exhibit outstanding optical properties, with an average optical transmittance of 86.88% in the visible region. This versatile TFE can promote the development of optoelectronic devices toward miniaturization and large‐scale integration in the future.