POSTECH Organic Electronics Laboratory, Polymer Research Institute, Department of Chemical Engineering, Pohang University of Science and Technology , Pohang, 790-784, Korea.
ACS Appl Mater Interfaces. 2012 Jun 27;4(6):3247-53. doi: 10.1021/am300600s. Epub 2012 Jun 8.
Silicon monoxide (SiO) thin films were introduced as an efficient interlayer for achieving plasma-based organic light-emitting diode (OLED) surface passivation. The SiO thin films could be consecutively formed via thermal evaporation, without breaking the vacuum, after deposition of the OLED cathode. The plasma resistivity and UV-blocking characteristics of the SiO interlayer protected the OLED devices against electrical and optical degradation during the plasma-enhanced atomic layer deposition (PEALD) and plasma-enhanced chemical vapor deposition (PECVD) passivation processes. In addition, the nonconformal deposition and hydroxyl group-rich surface characteristics of the SiO thin films yielded enhanced surface pinhole coverage and a higher initial film density in the subsequently deposited PEALD-based Al2O3 barrier film. As a result, the OLEDs with a SiO/Al2O3 bilayer passivation layer displayed a remarkably increased device shelf life compared to devices prepared using Al2O3-only passivation. A MOCON test showed that the water vapor transmission rate (WVTR) of the SiO/Al2O3 bilayer film was 0.0033 g/(m(2) day), 2.3 times lower than the rate of a single Al2O3 barrier film. The results of our study demonstrated the multipurpose role of a SiO interlayer in plasma-based OLED passivation. The layer acted as a damage-free protective layer for the underlying OLED devices and an assistant layer to improve the upper barrier film performance.
氧化硅（SiO）薄膜作为一种有效的层间材料，用于实现基于等离子体的有机发光二极管（OLED）表面钝化。SiO 薄膜可以通过热蒸发在不破坏真空的情况下连续形成，之后再沉积 OLED 阴极。SiO 层间层的等离子体电阻率和紫外线阻挡特性可以保护 OLED 器件免受等离子体增强原子层沉积（PEALD）和等离子体增强化学气相沉积（PECVD）钝化过程中的电和光降解。此外，SiO 薄膜的非共形沉积和富含羟基的表面特性使得在随后沉积的基于 PEALD 的 Al2O3 阻挡膜中，表面针孔覆盖率得到增强，初始膜密度更高。结果，与仅使用 Al2O3 钝化的器件相比，具有 SiO/Al2O3 双层钝化层的 OLED 器件的器件货架寿命显著增加。MOCON 测试表明，SiO/Al2O3 双层膜的水蒸气透过率（WVTR）为 0.0033 g/（m^2 天），比单层 Al2O3 阻挡膜低 2.3 倍。我们的研究结果表明，SiO 层间层在基于等离子体的 OLED 钝化中具有多种用途。该层充当了对底层 OLED 器件无损伤的保护层，并且是改善上层阻挡膜性能的辅助层。
