Realization of Thin Film Encapsulation by Atomic Layer Deposition of Al₂O₃ at Low Temperature

Abstract

We investigated Al2O3 atomic layer deposition growth layer for encapsulation of organic light emitting diodes (OLEDs). It was found that surface properties of these O3-based Al2O3 were superior to those of H2O based Al2O3 grown at relative higher temperatures. Therefore, the water vapor transmission rate of ∼60 nm thick Al2O3 films can be reduced from 4.9 × 10–4 g/(m2 day) (80 °C–H2O) to 8.7 × 10–6 g/(m2 day) (80 °C–O3) under a controlled environment of 20 °C and relative humidity of 60%. Besides, the OLEDs integrated with 80 °C–O3 based Al2O3 film were undamaged, and their luminance decay time was altered to a considerable extent.