Silica nanoparticle-embedded sol–gel organic/inorganic hybrid nanocomposite for transparent OLED encapsulation

We report a transparent moisture barrier coating fabricated with a silica nanoparticle-embedded organic/inorganic hybrid (S–H) nanocomposite. We used a photo-curable, cyclo-aliphatic epoxy based hybrid material (hyrimer) as the matrix and a solvent-less, monodisperse silica nanoparticles as the reinforcement responsible for creating tortuous diffusive path for moisture penetrants. The S–H nanocomposite barrier coating exhibits a single layer WVTR of 0.24 g/m2 day (Ca-test) and an optical transparency of 90% in the visible range. The performance of the barrier coating was also verified in an OLED lifetime measurement test, in which an OLED encapsulated with an S–H nanocomposite barrier coating showed significantly extended lifetime.

OLED lifetime measurement using a transparent, silica nanoparticle-embedded sol–gel hybrid (S–H nanocomposite) barrier coating is introduced. A significant improvement in the OLED lifetime is demonstrated.Figure optionsDownload as PowerPoint slideHighlights
► We introduce a moisture barrier coating for transparent encapsulation of OLED.
► The barrier coating is based on silica nanoparticle-embedded hybrid material.
► A single layer WVTR of ∼0.24 g/m2 day was confirmed in a Ca-test.
► Extended OLED lifetime with the barrier coating was demonstrated.