Reliable thin film encapsulation for organic light emitting diodes grown by low-temperature atomic layer deposition

We report on highly efficient gas diffusion barriers for organic light emitting diodes (OLEDs). Nanolaminate (NL) structures composed of alternating Al2O3 and ZrO2 sublayers grown by atomic layer deposition at 80 degrees C are used to realize long-term stable OLED devices. While the brightness of phosphorescent p-i-n OLEDs sealed by a single Al2O3 layer drops to 85% of the initial luminance of 1000 cd/m(2) after 1000 h of continuous operation, OLEDs encapsulated with the NL retain more than 95% of their brightness. An extrapolated device lifetime substantially in excess of 10 000 h can be achieved, clearly proving the suitability of the NLs as highly dense and reliable thin film encapsulation of sensitive organic electronic devices.