柔性有机发光器件的某些关键问题研究

Flexible organic light emitting device（FOLED）has attracted considerable interest due to their potential application in high value-added display commodities. However, the development of FOLED is still limited by the key issues of flexible encapsulation and transparent electrode. The primary aim of this proposal is to develop technologies of thin-film encapsulation (TFE) and ultrathin film metal electrodes (UFME) suitable for FOLED. (1) TFE section: By using MLD combined with ALD at the same chamber to fabricate high qualities organic-inorganic hybrid films. With the accurate controlling of film thickness according to fracture mechanics modeling, the higher critical strains can be achieved. Therefore, gas barrier and mechanical properties will be both improved by this method. (2) UFME section：UFME possess the potential to meet the low sheet resistance, high transparency and flexibility requirements of FOLED's electrodes applicatin. However, ultrathin film metal is not amenable to deposit on polymer substrate directly. Here, we will use MLD to fabricate an interlayer between UFME and polymer substrate as molecular adhesive additive to suppress the layers delamination and improve the UFME quality.

柔性有机电致发光器件（FOLED）可实现高附加值的显示产品，在很多领域具有广阔的应用前景。但达到FOLED显示的实用化，亟待解决器件柔性封装和柔性透明电极这两个关键问题。因此，本计划提出研究：（1）柔性薄膜封装新方法：根据水氧渗透理论和膜系断裂模型，利用原子层（ALD）/分子层（MLD）沉积技术制备有机层/无机层交叠结构封装薄膜，通过精确控制每个封装单元中有机层/无机层厚度，使薄膜获得较高的开裂临界应力，即保障封装薄膜有效阻隔水氧前提下，同时改善它的柔韧性。（2）超薄膜金属电极：超薄金属具有高电导率，可见光透明以及优良柔韧性的特点。利用MLD沉积有机分子作为柔性衬底的衍生薄膜（即分子粘合剂），使之与柔性衬底和金属分子之间产生有效附着，以抑制界面分层，促进金属薄膜在低厚度时连续性成膜，从而实现高质量的FOLED超薄膜金属电极。

有机电致发光器件(Organic Light-Emitting Diode，OLED)由于同时具备全固态、超薄、自发光、高亮度、高对比度、可应用于柔性器件等优异特性，被认为是下一代的照明和平面显示器新兴应用技术，但OLED的实用化目前还存在着诸多问题,其中器件在空气中的稳定性和可弯曲电极是制约柔性OLED发展的重要瓶颈。通过本课题的实施，我们实现了柔性OLED的原型器件，并在器件封装和透明电极制备研究中取得了突破：（1） 水气透过率（water vapor transmittation rate, WVTR）小于10^-6g/(m^2·day)；（2）柔性透明电极达到了方块电阻小于20Ω/□, 并且在550nm 波长光透过率大于83%；（3）围绕本工作发表SCI检索论文25篇，申请专利8项，其中6项已获得授权。