Air-stable flexible organic light-emitting diodes enabled by atomic layer deposition
Journal
Nanotechnology
Journal Volume
26
Journal Issue
2
Date Issued
2015
Author(s)
Abstract
Organic light-emitting diodes (OLED) are an energy-efficient light source with many desirable attributes, besides being an important display of technology, but its practical application has been limited by its low air-stability. This study demonstrates air-stable flexible OLEDs by utilizing two atomic-layer-deposited (ALD) films: (1) a ZnO film as both a stable electron-injection layer (EIL) and as a gas barrier in plastics-based OLED devices, and (2) an Al2O3/ZnO (AZO) nano-laminated film for encapsulating the devices. Through analyses of the morphology and electrical/gas-permeation properties of the films, we determined that a low ALD temperature of 70°C resulted in optimal EIL performance from the ZnO film and excellent gas-barrier properties [water vapor transmission rate (WVTR) <5 × 10-4 gm-2 day-1] from both the ZnO EIL and the AZO encapsulating film. The low-temperature ALD processes eliminated thermal damage to the OLED devices, which were severe when a 90°C encapsulation process was used, while enabling them to achieve an air-storage lifetime of >10 000 h. © 2015 IOP Publishing Ltd.
Subjects
Atomic layer deposition; Encapsulation; Lighting; Organic light emitting diodes
SDGs
Other Subjects
Atomic layer deposition; Atoms; Deposition; Diodes; Encapsulation; Energy efficiency; Gas permeable membranes; Light sources; Lighting; Metallic films; Temperature; Zinc oxide; Atomic layer deposited; Electron-injection layers; Encapsulation process; Energy efficient; Flexible organic light - emitting diodes; Low temperatures; Nano-laminated films; Water vapor transmission rate; Organic light emitting diodes (OLED)
Type
journal article