Oxygen and water barrier performance of the composite thin film of graphene and polydimethylsiloxane (PDMS)

We have demonstrated a new composite thin film for encapsulation consisting of polydimethylsiloxane (PDMS) and graphene. Graphene is a kind of hydrophobic material, causing that moisture could hardly penetrate into the surface of graphene. Graphene is usually fabricated by the method of Chemical Vapor Deposition (CVD). The atomic distance of graphene is very small; thus the water vapor channel from one layer to the nearby layer has been cut off, achieving the barrier of oxygen, water vapor and particle. Graphene and PDMS have high transmittance, making this method be widely used in various photoelectric devices. Meanwhile, graphene owes excellent heat dissipation which can reduce the temperature gradient and the junction temperature, thus improves the comprehensive performance and reliability of the device. Furthermore, PDMS has a good cohesiveness property, by which fit graphene very well and meet the requirement of encapsulation at the same time. Using Ca film test, we have found that the composite thin film has the greatest water oxygen barrier effect among them.