基于电荷和激子分布调控研究高性能有机白光二极管

发布时间：2018-08-08 19:10

【摘要】：由于有机发光二极管(OLED)具有效率高、色纯度好、功耗低、视角广、响应速度快、主动发光、超薄超轻以及可柔性折叠等优异性能,在显示和照明领域有广阔应用前景,受到学者和业界的广泛关注而成为研究热点。为进一步改善OLED性能,提高其在显示与照明市场上的竞争力,OLED(特别是白光OLED,WOLED)的高性能化研究具有重要意义。本文综述了OLED的发展历史、研究现状、器件结构、工作机理和涉及到的相关重要物理概念,重点介绍了四种类型的WOLED(全荧光WOLED、全磷光WOLED、杂化WOLED、延迟荧光WOLED)。通过研究采用不同方法调控器件中电荷和激子的分布,深入阐明WOLED器件中存在的电荷注入与传输、激子形成与扩散、激子俘获与复合等的发光机制,研制了一系列高性能WOLED,主要创新性成果如下:1)采用通过客体调控电荷和激子的分布的思路,设计了简单的单发光层器件结构,研制出了结构简单、效率高、效率滚降低、色稳定性好的全磷光WOLED器件。器件的最大发光效率和功率效率分别为113.6 cd/A和95.5 lm/W。在亮度1000 cd/m2时,发光效率可达111.7 cd/A或75.5 lm/W,为目前公开发表的科学文献中效率最高的单发光层WOLED。该器件色度稳定,在工作亮度范围内它的色坐标基本不变。论文研究了该类器件客体在稳定色坐标方面的作用,证实了通过客体调控电荷和激子的分布能够稳定光色。2)系统研究了n型间隔层对杂化WOLED性能的影响,发现n型间隔层的三线态能级位置较电子迁移率或空穴阻挡能力对器件性能的影响更大。通过选择更为有效的Bepp2(吩基吡啶铍)作为间隔层,实现了长寿命杂化WOLED。在初始亮度1000 cd/m2下,利用加速老化测试方法,估算寿命超过3万小时。这项成果对设计新的器件结构,提高WOLED发光寿命具有一定的借鉴意义。3)研制了高性能深蓝色聚集诱导OLED器件,实现的器件性能为:色度坐标(0.17,0.14),发光峰449 nm,启亮电压2.75 V,最高亮度17721 cd/m2、最高效率为4.3 lm/W,1000 cd/m2亮度下效率为3.6 lm/W,效率滚降低。首次利用蓝色聚集诱导发光材料制备出了一系列高性能杂化WOLED。其中,对于双色杂化WOLED:1)当器件中的间隔层TAPC:TmPyPB比例为1:0时,实现了光色稳定的WOLED,功率效率为32.0 lm/W;2)当间隔层TAPC:TmPyPB比例为0.8:0.2时,实现了光色稳定、高效率、低效率滚降的WOLED器件,功率效率为38.9 lm/W;3)当间隔层TAPC:TmPyPB比例为0.5:0.5时,实现了在10000 cd/m2亮度时,器件效率分别为70.2 cd/A和43.4 lm/W的WOLED器件。最后,利用蓝、黄、红三色发光材料,研发出了首个具有太阳光色温特性的杂化WOLED,其色温可在2328 K到10690 K范围内变化。结果表明,利用蓝色聚集诱导荧光体有希望制备高性能杂化WOLED。4)开发出了一类主客体组合体系实现高效WOLED。首次采用NPB同时作为蓝光发射体和单发光层杂化主体,制备双色WOLED。当发光客体Ir(dmppy)2(dpp)的浓度为1.5%时,单发光层杂化WOLED的最大效率为65.3 lm/W,启亮电压和亮度在1000 cd/m2时的电压分别为2.4 V和3.45 V。论文讨论了高浓度客体(1%)的单发光层杂化WOLED的工作机理。在该类器件中,蓝光由NPB主体本身提供,黄光来自Ir(dmppy)2(dpp)磷光客体,通过不完全的F?rster能量转移和Dexter能量转移同时产生蓝光和黄光获得白光。将该思想用于双发光层杂化WOLED中,得到器件的最大效率为17.2 lm/W和亮度为1000cd/m2时的10.2 lm/W(3.85 V),显色指数CRI值为93,这为研制结构简单、低驱动电压、高CRI的WOLED提供了一种可行方法。5)研制了高效率的柔性有机白光器件。通过优化器件的机械性、电学性和光学性,实现了最大效率为101.3 lm/W的柔性WOLED,在亮度为1000 cd/m2时,其效率为58.2lm/W。该器件亮度从100 cd/m2到10000 cd/m2变化时,色坐标变化范围仅为(0.004,0.005),表明该器件色坐标稳定。此结果为获得高性能柔性WOLED提供了可参考的方法。
[Abstract]:Organic light-emitting diode (OLED) has high efficiency, good color purity, low power consumption, wide angle of view, fast response, active luminescence, ultra-thin ultra light and flexible folding and so on. It has a broad application prospect in the field of display and lighting. It has become a hot topic in the field of attention of scholars and industry. In order to further improve the performance of OLED, improve the performance and improve the performance of the organic light emitting diode The high performance research of OLED (especially the white light OLED, WOLED) is of great significance in the competitiveness of the display and lighting market. The history of the development of OLED, the status of the research, the structure of the device, the working mechanism and the related important physical concepts are summarized in this paper, and the four types of WOLED (full phosphor WOLED, full phosphor WOLED, hybrids) are introduced. WOLED, delayed fluorescence WOLED). Through the use of different methods to regulate the distribution of charge and exciton in devices, the charge injection and transmission, exciton formation and diffusion, exciton capture and recombination in WOLED devices are clarified, and a series of high performance WOLED are developed. The main innovative results are as follows: 1) use the object modulation. In order to control the distribution of charge and exciton, a simple single light layer device is designed. A full phosphor WOLED device with simple structure, high efficiency, low efficiency, low efficiency and good color stability is developed. The maximum luminous efficiency and power efficiency of the device are 113.6 cd/A and 95.5 lm/W. respectively at 1000 cd/m2, and the luminous efficiency can reach 111.7 cd/A or 7. 5.5 lm/W, for the most efficient single light layer WOLED. in the published scientific literature, the chromaticity of the device is stable and its color coordinates are basically unchanged in the working luminance range. The paper studies the role of the object in stabilizing the color coordinates, and confirms that the distribution of the charge and exciton can stabilize the light color.2 system through the object control. The effect of N spacer layer on the performance of hybrid WOLED was investigated. It was found that the three line state energy level of the N interlayer has greater influence on the performance of the device than the electron mobility or hole blocking ability. By choosing a more effective Bepp2 (phenylpyridine beryllium) as the spacer layer, the long life hybrid WOLED. is utilized under the initial brightness of 1000 cd/m2. The accelerated aging test method has estimated life over 30 thousand hours. This achievement has a certain reference for designing new device structure and improving WOLED luminescence life.3). A high-performance deep blue aggregation induced OLED device has been developed. The performance of the device is: chromaticity coordinates (0.17,0.14), luminescence peak 449 nm, bright voltage 2.75 V, and maximum brightness 17721 Cd/m2, the maximum efficiency is 4.3 lm/W, the efficiency of 1000 cd/m2 is 3.6 lm/W, and the efficiency is reduced. A series of high performance hybrid WOLED. is prepared by using the blue aggregation induced luminescent material for the first time. For the dual color hybrid WOLED:1), when the TAPC:TmPyPB ratio of the spacer is 1:0 in the device, the light color stable WOLED is realized and the power efficiency is 32.. 0 lm/W; 2) when the TAPC:TmPyPB ratio of the interlayer is 0.8:0.2, the WOLED device with stable light color, high efficiency and low efficiency rolling down, the power efficiency is 38.9 lm/W; 3) when the TAPC:TmPyPB ratio of the interlayer is 0.5:0.5, the device efficiency is 70.2 cd/A and 43.4 lm/W respectively, when the 10000 cd/m2 brightness is respectively. Finally, blue, yellow and red are used. Three color luminescent materials have developed the first hybrid WOLED with the characteristics of the solar and color temperature. The color temperature can vary from 2328 K to 10690 K. The results show that the use of blue aggregation induced fluorescence is expected to produce high performance hybrid WOLED.4. A class of host and guest combinations have been developed to achieve high efficiency WOLED. for the first time to use NPB as blue. The maximum efficiency of the single luminescent WOLED hybrid WOLED is 65.3 lm/W and the voltage and brightness at 1000 cd/m2 are respectively 2.4 V and 3.45 V., respectively, when the concentration of the dual color WOLED. (dmppy) 2 (DPP) is 1.5%, and the voltage and brightness at 1000 cd/m2, respectively, are 2.4 V and 3.45 V., respectively, to discuss the work of the single light layer hybrid WOLED. In this kind of device, the blue light is provided by the NPB body itself, and the yellow light comes from the Ir (dmppy) 2 (DPP) phosphorescent object. The blue light and the yellow light are produced by the incomplete F? Rster energy transfer and the Dexter energy transfer. The idea is used in the double luminescent layer hybrid WOLED, and the maximum efficiency of the device is 17.2 lm/W and the luminance is 1000cd/m. 10.2 lm/W (3.85 V) at 2 and a color index CRI value of 93, which provides a feasible way to develop a simple structure, low driving voltage, and a high CRI WOLED. A flexible organic white light device is developed. By optimizing the mechanical, electrical and optical properties of the device, the maximum efficiency of the flexible WOLED with a maximum efficiency of 101.3 lm/W is realized, and the brightness is 1000. When cd/m2, the efficiency of the device is 58.2lm/W., when the brightness of the device varies from 100 cd/m2 to 10000 cd/m2, the variation range of color coordinates is only (0.004,0.005), indicating that the color coordinates of the device are stable. This result provides a reference for obtaining high performance flexible WOLED.
【学位授予单位】：华南理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN383.1

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