O2 and H2O barrier materials suitable for the protection of LCDs and flexible OLEDs are fabricated on a polymer substrate using dense inorganic barrier layers. A polymer surface having a low surface roughness has an inorganic layer of aluminum or silicon oxides deposited thereupon using ion-assisted vacuum deposition with an argon ion gun, which treatment surprisingly provides a smoothing effect on the surface of the polymer. By pretreatment of prefabricated polymeric film with ion-gun enhanced plasma in the presence of oxygen, commercially available heat-stabilized PET and PEN films can be directly employed as substrates. Protective polymer layers are optionally coated upon the thin inorganic barrier layer.
