Ultra‐thin flexible nano‐composite encapsulation layer consists of graphene oxide and PDDA bi‐layer was prepared using layer‐by‐layer processing method. The encapsulation layer on PET substrate decreased WVTR of the substrate by more than three orders of magnitude and lifetime of OLED on the PET substrate was similar to that on glass substrate.

Ultra-thin flexible encapsulation layer consists of graphene oxide/polymeric multilayer were prepared using layer-by-layer processing method. The encapsulation layer on a PET substrate reduced the substrate WVTR by more than five orders of magnitude.