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

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^–4g/(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