Air-Stable flexible organic light-emitting diodes enabled by atomic layer deposition

作者：Lin Yuan Yu^*; Chang Yi Neng; Tseng Ming Hung; Wang Ching Chiun; Tsai Feng Yu

来源：Nanotechnology, 2015, 26(2): 024005.

DOI：10.1088/0957-4484/26/2/024005

• organic light emitting diodes
• lighting
• encapsulation
• atomic layer deposition

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 degrees C resulted in optimal EIL performance from the ZnO film and excellent gas-barrier properties [ water vapor transmission rate (WVTR) < 5 x 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 degrees C encapsulation process was used, while enabling them to achieve an air-storage lifetime of > 10 000 h.

• 出版日期2015-1-16