Co-sputtered oxide thin film encapsulated organic electronic devices with prolonged lifetime

Effective top-side thin film encapsulation for organic light-emitting devices (OLEDs) was achieved by deposition of a multi-layer water diffusion barrier stack to protect the device against moisture permeation. The barrier stack was formed by alternative depositions of co-oxide and fluorocarbon (CF_x) films. The co-oxide layer was fabricated by magnetron co-sputtering of silicon dioxide (SiO₂) and aluminum oxide (Al ₂O₃). While the CF_x layer was formed by plasma enhanced chemical vapor deposition. The water vapor transmission rate of the optimized diffusion barrier stack can be down to 10^-6 g/m ²/day. The OLEDs encapsulated with the multilayer stack have been shown to have operation lifetime of over 18,000 h which is nearly the same as devices with conventional glass-cover encapsulation. © 2011 Elsevier B.V. All rights reserved.