Organic materials based electronics have been candidate for the commercialization of flexible electronics and flexible photovoltaics. Organic materials have many advantages such as light weight, impact resistance, low cost, solution and dry-processable. Nowadays, displays featuring in an ultra-thin thickness, comfort, flexible form, high contrast ratio and brightness have been spotlight in the mobile telecommunication. Especially, a next-generation OLED display is possible for a bendable, foldable, stretchable and changeable like a paper-type display. However, the encapsulation technology is necessary in order to ensure the stability of the device because an organic materials used in the OLEDs easily oxidized by moisture and oxygen. For existing technology, using a metal can or glass lid is used to protect the OLED display, but in the future thin film encapsulation (TFE) is an essential to protect the flexible display. Recently, TFE made of organic/inorganic or inorganic/inorganic gas barrier for display has been studied actively on a low moisture permeability (water vapor transmission rate, WVTR) and a low permeation rate of oxygen (oxygen transmission rate, OTR).
In this study, we applied the plasma enhanced chemical vapor deposition (PECVD) method and initiated-chemical vapor deposition (i-CVD) on the deposition of a gas barrier film for flexible displays. In PECVD, we used a various monomers such as HMDSO, n-hexane and furan coated on poly(ethylene naphthalate) (PEN) substrate. Especially, we evaluated for HMDSO polymerized film properties under flow rate of the carrier gas. The film higher the proportion of oxygen was a hydrophilic property and Si-O bond increased. However, the WVTR value of Ar:O2=1:9 does not low value due to formation of dust particle.
Second, we estimated i-CVD polymerized films. The i-CVD process is a single-step, solvent free and low energy. Thin film made of i-CVD process has an uniformity and avoiding undesirable side reaction. We confirmed polymer films retained functional group by FT-IR, morphology of film by SEM and AFM. The moisture barrier property of WVTR value was measured by electrical Calcium test under 85℃ and 85% RH.