Lin Yuan-Yu, Chang Yi-Neng, Tseng Ming-Hung, Wang Ching-Chiun, Tsai Feng-Yu
Department of Materials Science and Engineering, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei, Taiwan, People's Republic of China.
Nanotechnology. 2015 Jan 16;26(2):024005. doi: 10.1088/0957-4484/26/2/024005. Epub 2014 Dec 19.
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) g m(-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.
有机发光二极管（OLED）是一种节能光源，除了是一项重要的显示技术外，还具有许多理想特性，但其实际应用因空气稳定性低而受到限制。本研究通过利用两种原子层沉积（ALD）薄膜展示了空气稳定的柔性OLED：（1）ZnO薄膜，作为稳定的电子注入层（EIL），同时作为基于塑料的OLED器件中的气体阻挡层；（2）Al2O3/ZnO（AZO）纳米层压薄膜，用于封装器件。通过对薄膜的形态和电/气体渗透性能进行分析，我们确定70°C的低温ALD可使ZnO薄膜获得最佳的EIL性能，并且ZnO EIL和AZO封装薄膜都具有出色的气体阻挡性能[水蒸气透过率（WVTR）<5×10（-4）g m（-2）day（-1）]。低温ALD工艺消除了对OLED器件的热损伤，当采用90°C封装工艺时，热损伤很严重，同时使它们能够实现>10,000小时的空气储存寿命。
