碳量子点基有机电致发光器件关键制造技术研究

发布时间：2018-07-15 20:13

【摘要】：有机电致发光二极管(OLED)经过数十年的发展已经取得了令人瞩目的突破和成就,无论是在研究领域还是在商业化的道路中都取得了极大的进步。但是,OLED器件目前仍存在一些问题,例如可供选择的发光材料较少并且普遍比较昂贵、稳定性和寿命较低、制备工艺繁琐等。针对以上问题,论文提出了一些新的想法和思路,使用了清洁、环保和廉价的碳量子点材料应用在OLED器件中,旨在提高器件发光性能、降低制备成本以及减少环境污染。制备了碳量子点基有机电致发光器件。通过微波法制备了碳量子点纳米材料,并且对所制得的碳量子点进行了TEM表征。论文中采用真空镀膜技术和旋转涂覆技术相结合的方法将碳量子点制备在OLED器件的有机结构中,并分别研究了碳量子点材料对结构为ITO/m-MTDATA/NPB/CDs/BCP/Alq3/Al的蓝光OLED器件、结构为ITO/m-MTDATA/NPB/CDs/Alq3:Rubrene:DCJTB/Alq3/Al的红光OLED器件和结构为ITO/m-MTDATA/NPB/CDs/MADN:Rubrene/Alq3/Al的黄光OLED器件性能的影响。实验结果表明,加入碳量子点功能层的OLED器件在发光亮度、发光效率等方面明显优于典型的OLED器件。制备了碳量子点生物荧光粉,研究了以碳量子点作为荧光粉的转化发光器件。基于淀粉对碳量子点发光猝灭的抑制作用,制备了以淀粉为基质的碳量子点荧光粉。论文中制备了发光波长为463 nm的蓝光OLED器件,在OLED器件的激发下,荧光粉呈现出了稳定的绿光发射。另外,通过改变荧光粉涂层厚度,研究了荧光粉厚度对器件光谱和色度的影响。最终在荧光粉厚度为1 mm时,所制备的荧光粉器件表现为色坐标为(0.35,0.46)的绿光发射。实验证明碳量子点荧光粉可以有效地改变器件的光谱和色度,实现光的调制作用。研究了氧化镍纳米结构阳极缓冲层对蓝光OLED器件性能的影响。通过对NiO颗粒形貌的测量和表征发现,电化学沉积法所制备的NiO颗粒具有良好的纳米结构。根据Ni薄膜沉积时间的不同,论文中制备了四组对比实验。实验结果表明,纳米结构NiO缓冲层能够有效地提高空穴注入效率,从而增加空穴-电子对的产生和复合效率。最终,当Ni薄膜的沉积时间为30 s时,器件的发光性能最佳。分别制备了基于PET衬底和玻璃衬底的OLED器件,研究了柔性衬底材料对器件性能的影响。实验结果表明,基于PET衬底的多层结构器件展现出了良好的发光特性。但是,相比于刚性衬底器件,柔性器件在发光亮度、发光效率和电流密度上仍有不足。针对柔性器件目前所存在的问题,论文提出了在柔性衬底材料和阳极材料之间加入SiO_2改善层的措施。论文最后介绍了两种柔性OLED器件封装技术,一种方法是在器件上制备薄膜阻挡层;另一种方法是在基板和功能层上加入柔性盖板。两种封装技术都是为提高柔性显示性能提供参考。
[Abstract]:Organic electroluminescent diodes (OLED) have made remarkable breakthroughs and achievements after decades of development, both in the field of research and in the road of commercialization has made great progress. However, there are still some problems in OLED devices, such as less and more expensive luminescent materials available, low stability and lifetime, cumbersome fabrication process and so on. Aiming at the above problems, this paper puts forward some new ideas and ideas, using clean, environmentally friendly and cheap carbon quantum dot materials in OLED devices to improve the luminescence performance of the devices, reduce the cost of preparation and reduce environmental pollution. Organic electroluminescent devices based on carbon quantum dots were fabricated. Carbon quantum dots were prepared by microwave method and characterized by TEM. In this paper, carbon quantum dots are fabricated in the organic structure of OLED devices by the combination of vacuum coating technology and rotating coating technology. The blue OLED devices with ITO / m-MTDATAP / NPB / CDsP / BCPP / Alq3 / Al structure are studied respectively. The red OLED with the structure of ITO / m-MTDATA-NPB / CDsAlq3: Rubrene-DCJTB / Alq3 / Al and the yellow OLED with ITO / m-MTDATA-NPB / NPB / MADN / Rubrene-R / Alq3 / Al has an effect on the performance of yellow OLED devices. The experimental results show that the OLED device with carbon quantum dot function layer is superior to the typical OLED device in luminance and luminous efficiency. Carbon quantum dots (QDs) as phosphors were prepared and the conversion luminescent devices with carbon QDs as phosphors were studied. Based on the inhibition of starch on the luminescence quenching of carbon quantum dots, the phosphors based on starch were prepared. Blue OLED devices with a wavelength of 463 nm have been fabricated in this paper. Under the excitation of OLED devices, the phosphors exhibit stable green emission. In addition, the influence of phosphor thickness on the spectrum and chromaticity of the device was studied by changing the thickness of phosphor coating. Finally, when the phosphor thickness is 1 mm, the phosphor exhibits green emission with a color coordinate of (0.35 ~ 0.46). Experimental results show that carbon quantum dot phosphors can effectively change the spectrum and chroma of the device and realize the modulation of light. The effect of nickel oxide nanostructure anode buffer layer on the performance of blue light OLED devices was investigated. By measuring and characterizing the morphology of nio particles, it is found that the nio particles prepared by electrochemical deposition have good nanostructures. According to the different deposition time of Ni film, four groups of comparative experiments were prepared in this paper. The experimental results show that the nio buffer layer of nanostructure can effectively improve the efficiency of hole injection and thus increase the generation and recombination efficiency of hole electron pairs. Finally, when the deposition time of Ni film is 30 s, the luminescence performance of the device is the best. OLED devices based on PET and glass substrates were fabricated, and the effects of flexible substrate materials on the properties of the devices were investigated. The experimental results show that the multilayer devices based on PET substrate exhibit good luminescence characteristics. However, compared with rigid substrate devices, flexible devices still lack luminance, luminous efficiency and current density. Aiming at the existing problems of flexible devices, the measures of adding SiO2 layer between flexible substrate material and anode material are put forward in this paper. Finally, two kinds of flexible OLED device packaging techniques are introduced, one is to fabricate thin film barrier layer on the device, the other is to add flexible cover plate to the substrate and functional layer. The two packaging technologies provide reference for improving the performance of flexible display.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN383.1

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