光学功能层在柔性封装OLED中的应用

发布时间：2018-11-14 10:33

【摘要】：近年来,柔性顶发射有机电致发光器件(OLED)以其白发光器件特有的高对比度、宽色域、低功耗以及轻、薄、可弯曲等优点,在移动显示领域表现出优势,取得了越来越大的市场份额,也成为了显示领域的理论研究和技术开发的热点。然而,顶发射OLED器件的视角、出光效率的提升等仍是尚未得到满意解决的问题。柔性结构的带入使其又出现了新的问题。和以往采用(玻璃、金属)平板封装的刚性器件相比,虽然薄膜封装具有良好的弯折特性,但与水氧隔绝性能极佳的玻璃封装盖板相比,薄膜层的封装效果首先成为了大家的关注热点。薄膜封装逐渐发展出有机无机多层叠加的复合封装层结构,大大提高了 OLED器件的寿命,达到了可以应用的水平。但是,与(玻璃)平板封装相比,薄膜封装层对器件出光特性有负面影响,从而影响到了器件的效率和功耗,这会对OLED在移动显示应用的优势有一定的削弱。因此改善薄膜封装对器件出光特性造成的影响具有重要作用。本文重点针对与薄膜封装相关的光学功能层对柔性顶发射OLED器件出光特性影响进行研究。首先从薄膜封装以及器件结构入手,在理论方面分析了器件出光特性受封装相关结构的影响,认为主要是由于封装薄膜层影响了器件出光通路的相关光学结构,从而改变了之前按玻璃平板封装优化的光学结构和相关参数引起的,这种假设通过实验和分析得到了证实。之后我们利用光学模型针对光学功能层的参数进行模拟分析,根据结果我们采用通过在原有刚性器件结构内最上层的覆盖层(capping layer)和柔性封装薄膜之间加入一层低折射率间隔层对器件出光效率进行改善的方案,通过模拟优化实验方案,最后进行实验验证。在我们的实验中,薄膜封装顶发射OLED器件的效率从玻璃盖板封装参照器件的64%提升到了 84%,证实了这是一种切实有效的改善柔性封装OLED器件出光特性的方法,并为柔性封装的光学改善提供了思路。
[Abstract]:In recent years, flexible top emitting organic electroluminescent devices (OLED) have shown their advantages in the field of mobile display due to their unique advantages of high contrast, wide color gamut, low power consumption, light, thin and flexible, etc. It has gained more and more market share, and has also become a hot spot in theory research and technology development in display field. However, the angle of view of top emitting OLED devices and the improvement of optical efficiency are still not solved satisfactorily. The introduction of flexible structure makes it appear new problems. Compared with the rigid devices used in the (glass, metal) flat packaging in the past, although the thin film packaging has good bending characteristics, it is compared with the glass packaging cover plate which has excellent water-oxygen isolation performance. The packaging effect of thin film layer has become the focus of attention. The composite packaging layer structure of organic and inorganic multilayer superposition has been developed in thin film packaging, which greatly improves the life of OLED devices and reaches the applicable level. However, compared with the (glass) flat panel packaging, the film packaging layer has a negative impact on the optical characteristics of the device, thus affecting the efficiency and power consumption of the device, which will weaken the advantage of OLED in mobile display applications. Therefore, it is important to improve the effect of film packaging on the output characteristics of the device. In this paper, the effects of optical functional layers related to film packaging on the output characteristics of flexible top emitting OLED devices are studied. Firstly, from the aspects of film packaging and device structure, the paper analyzes theoretically that the optical characteristics of the device are affected by the packaging structure, which is mainly due to the influence of the packaging film layer on the optical structure of the output path of the device. Therefore, the optical structure and related parameters optimized for glass plate packaging are changed. This hypothesis is confirmed by experiments and analysis. Then we use the optical model to simulate and analyze the parameters of the optical functional layer. According to the results, we adopt a scheme to improve the output efficiency of the device by adding a layer of low refractive index spacer between the top layer of (capping layer) and the flexible packaging film in the original rigid device structure, and optimize the experimental scheme by simulation. Finally, experimental verification is carried out. In our experiment, the efficiency of top-emitting OLED devices in thin film packaging has increased from 64% to 84% of the reference devices for glass cover packaging, which proves that this is a practical and effective method to improve the output characteristics of flexible packaging OLED devices. It also provides ideas for the optical improvement of flexible packaging.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN383.1

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