Abstract
Dependences of gas-barrier performance on the deposition temperature of atomic-layer-deposited (ALD) Al <sub>2</sub> O <sub>3</sub> , HfO <sub>2</sub> , and ZnO films were studied to establish low-temperature ALD processes for encapsulating organic light-emitting diodes (OLEDs). By identifying and controlling the key factors, i.e. using H <sub>2</sub> O <sub>2</sub> as an oxidant, laminating Al <sub>2</sub> O <sub>3</sub> with HfO <sub>2</sub> or ZnO layers into AHO or AZO nanolaminates, and extending purge steps, OLED-acceptable gas-barrier performance (water vapor transmission rates ∼ 10 <sup>-6</sup> gm <sup>-2</sup> d <sup>-1</sup> ) was achieved for the first time at a low deposition temperature of 50 °C in a thermal ALD mode. The compatibility of the low-temperature ALD process with OLEDs was confirmed by applying the process to encapsulate different types of OLED devices, which were degradation-free upon encapsulation and showed adequate lifetime during accelerated aging tests (pixel shrinkage <5% after 240 h at 60 °C/90% RH).