喷墨打印技术制备PLED显示屏及相关研究

发布时间：2018-01-24 15:16

本文关键词： 聚合物发光显示器喷墨打印技术超疏水界面分子自组装　出处：《华南理工大学》2016年博士论文　论文类型：学位论文

【摘要】：有机电致发光显示器(Organic Light-emitting Diode Display,OLED Display)因具有低能耗、宽视角、高开关速率和高对比度等特点而显示出巨大的应用潜力。聚合物发光显示器(Polymer Light-emitting Diode Display,PLED Display)因其材料发光颜色在全可见光区内可调、可溶液简单加工及适用于柔性大面积器件的生产而吸引了更多的目光。旋涂法无疑是最简便快捷并且成膜质量好的溶液加工方式,但一般只能用于单色显示屏制备,不能进行不同颜色的聚合物薄膜的图案化来实现全彩显示,而且材料浪费大。在聚合物发光薄膜图案化技术中,喷墨打印因为具有加工过程简单高效、材料利用率高、适用于溶液加工、适用于柔性衬底、易于卷对卷工艺的整合和自动化等优点,被认为是最具有应用潜力的技术。高质量聚合物薄膜的制备是PLED器件制作的关键,但喷墨打印液滴在干燥过程中通常伴随着“咖啡环”现象,造成薄膜不均匀沉积。我们以聚芴蓝光材料PFSO为研究对象,系统地研究了溶剂类型、墨水浓度、基底温度、打印参数等因素对其成膜形貌的影响。实验表明,这些影响因素都能间接地影响液滴三相接触线的钉扎时间和钉扎后形成的毛细流动强弱,从而影响液滴的干燥形貌。延迟或者抑制接触线的钉扎有利于点状薄膜的形成。而在接触线钉扎后,可以通过减弱由于溶剂挥发不均匀而形成的毛细流动,使得溶剂蒸发速率与溶质的迁移速率相平衡,实现溶质的均匀沉积。我们通过对溶剂和浓度的系统调控,成功地利用单溶剂墨水在室温条件的无处理基板上打印出边界清晰、表面均匀的薄膜。在喷墨打印制备PLED显示屏过程中,如何配制可打印的墨水得到稳定的液滴,如何实现液滴的精确定位,如何调控薄膜成膜质量和分辨率以及如何优化器件结构,都是制备高性能显示屏时需要考虑的重要因素。我们通过调整打印参数和打印方式来调控液滴打印稳定性、尺寸大小以及精确定位,实现打印液滴在对应高分辨率的像素内均匀沉积而无溢出。此外,我们设计了新型的线型像素结构基板,成功简化了操作工艺,同时提高了像素内薄膜的均匀性;最后通过进一步优化缓冲层(Buffer Layer)厚度和发光层的厚度,实现了打印器件效率达到对比器件(对应旋涂器件)效率的75%。在解决一系列工艺问题后,我们成功打印出无缺陷的3英寸、120ppi的聚合物蓝光显示屏。固体表面的浸润性对溶液加工薄膜的均匀性和打印分辨率有一定的影响,是全溶液加工技术面临的一项重要科学问题。通过对固体表面结构及液体行为的研究,调控固体表面的浸润性,对实验研究和实际应用都有着重要的意义。特别地,超疏水作为浸润性的一个极端现象,有着广泛的应用前景。我们利用全溶液加工的方法,制备了独立自支撑、柔性、透明、具有荧光发射特性的有机超疏水复合薄膜。其中,通过有机化合物1的分子自组装得到的分等级微/纳结构实现了薄膜的表面液体浸润状态由Wenzel态向Cassia态的转变。制备的复合薄膜表现出了优异的超疏水性,而且对从强酸到强碱整个PH范围内的水溶液都表现出了同样的超疏水性能,更兼有良好的环境稳定性。更特别的是固体材料分子本身属于共轭分子,具有显著的荧光特性,这也预示着其在新型智能、光电传感等领域的应用潜力。
[Abstract]:Organic electroluminescent display (Organic Light-emitting Diode Display, OLED Display) because of its low energy consumption, wide viewing angle, high speed switching and high contrast and showed great potential in application. The polymer light-emitting display (Polymer Light-emitting Diode Display, PLED Display) as the material in the whole visible light color adjustable. The solution can be simple processing and is suitable for flexible production and large area devices have attracted more attention. The spin coating method is undoubtedly the most convenient and solution processing films of good quality, but generally only can be used for the preparation of monochrome display, not patterned polymer films of different colors to achieve full-color display, and materials waste. In polymer light-emitting film patterning technology, inkjet printing because of its processing process is simple and efficient, high material utilization rate, suitable for processing solution, Suitable for flexible substrate, easy integration and automation of roll roll process, is considered to be the most potential technology. High quality polymer film preparation is the key to fabricate PLED devices, but the inkjet droplet in the drying process is usually accompanied by a "coffee ring" phenomenon, caused by uneven deposition of thin film we in polyfluorene blue emitting material PFSO as the research object, systematically studied the type of solvent, ink concentration, substrate temperature, influence of printing parameters and other factors on the film morphology. Experimental results show that these factors can indirectly affect the droplet three contact line pinning time and capillary flow strength of tie nail after the formation, thus affecting the morphology of drying droplets. Delay or inhibition of the contact line pinning is conducive to the formation of films. In the point of contact line pinning, can decrease the solvent evaporation uneven form Capillary flow, the migration rate of solvent evaporation rate and solute equilibrium, realize the uniform deposition of solute. Through systematic regulation of the solvent and the concentration of no substrate successfully by using the single solvent ink at room temperature on the print out a clear boundary, the surface of thin film is uniform. In the preparation of ink-jet printing PLED display process how to prepare, print ink droplet stability, how to achieve precise positioning of the droplet, how to control the film quality and resolution and how to optimize the device structure, are the important factors to be considered in the preparation of high performance display. We adjust the print and print parameters to control droplet print stability. The size and precise positioning, print droplets in pixels in high resolution uniform deposition without overflow. In addition, we design a new type of pixel node The success of the substrate, simplifies the operation process, and improve the uniformity of the pixels inside the film; finally through the further optimization of the buffer layer (Buffer Layer) and the thickness of the emitting layer thickness, the printing device efficiency of contrast devices (corresponding spin devices) efficiency of 75%. in solving a series of technical problems, we successfully print a defect free 3 inches 120ppi screen. Blue polymer has certain effect on solid surface wettability of solution processing uniformity and print resolution, is an important scientific problem facing all solution processing technology. Through the research on the structure of solid surface and liquid behavior, invasive regulation of solid surface. The experimental research and practical application has important significance. In particular, the super hydrophobic as an extreme phenomenon of invasive, has a wide application prospect. We use the solution processing The method of preparation of self support, flexible, transparent, with the fluorescence emission properties of super hydrophobic organic composite films. Among them, 1 organic compounds by molecular self-assembly of hierarchical micro / nano structure of the surface of the liquid film infiltration transition state by Wenzel state to the Cassia state of the prepared composite. The film showed excellent superhydrophobicity, and the aqueous solution from strong acid to alkali the whole range of PH have shown super hydrophobic properties also, with a good environment stability. Especially for the solid material itself belongs to molecular conjugated molecules with fluorescence characteristics significantly, which also indicates that the a new intelligent, potential applications of photoelectric sensing and other fields.

【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】：TN873.3;TP391.73

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