有机电致发光器件中有机薄膜的LB法制备技术研究

发布时间：2018-05-02 06:40

本文选题：OLED + Langmuir-Blodgett膜法　；参考：《重庆大学》2015年硕士论文

【摘要】：有机电致发光器件(Organic electroluminescent Device,简称OLED),具有轻薄、面发光、自发光,柔性可弯曲、透明等优势,在照明以及显示领域具有广阔的应用前景。OLED器件有机层为有机化学材料,利用有机材料制备发光层工艺有真空蒸镀、旋涂、喷墨打印、织网印刷等工艺。这几种工艺制备的有机层中分子呈无序排列,而载流子在分子无序排列的有机薄膜中传输效率较低,从而对OLED器件的光致发光效率有一定影响。L-B(Langmuir-Blodgett)膜技术是在适当的条件下,将兼具亲水头和疏水尾的两亲性分子分散在水面上,经逐渐压缩其水面上的占有面积,使其排列成单分子层,再将其转移沉积到固体基底上所得到的一种分子有序性排列薄膜。利用LB膜法制备的有机发光层由于分子有序排列,载流子传输效率增加,进而提高OLED器件的电光效率。目前有研究者将LB膜技术应用在化学领域,利用分子的有序排列提高催化效率;也有研究者将LB膜技术运用到生物半透膜领域。将LB膜技术运用到OLED器件的有机层制备中报道甚少,研究LB膜在有机层中的作用机理更是鲜有报道。本文研究了OLED器件中常见的空穴传输材料-聚乙烯基咔唑(PVK)的LB膜法制备原理和技术。为了明确LB膜中分子有序排列对薄膜光学以及电学性能的影响,同时采用LB膜法和旋涂法制备PVK有机薄膜,并建立LB膜法和旋涂法制备PVK薄膜模型。对两种工艺制备的PVK有机薄膜进行光学和电学性能的测试与比较。本文具体工作如下:①建立了PVK有机薄膜的LB膜法制备模型。包括有PVK的甲苯溶液在超纯水表面分散的均匀性以及稳定性等。分析基片亲水性机理以及薄膜与基片、薄膜与薄膜之间的作用机理。最后从理论上说明了分子有序排列对载流子传输的影响。②研究了LB膜法制备PVK薄膜过程中不同亲水工艺对ITO基片透光率以及面电阻影响。利用自制LB拉膜仪制备PVK LB膜,研究了分散剂比例对PVK薄膜电阻率以及膜厚的影响。制备了单层至多层PVK LB薄膜并测试薄膜的膜厚、紫外-可见吸光光谱、荧光光谱、电阻率等性能参数。③根据旋涂规律,通过旋涂实验中改变不同浓度以及转速得到的数据,建立PVK的旋涂模型。制备与LB膜法相同厚度的PVK薄膜,并测试薄膜膜厚、吸光度、荧光光谱等性能参数。④分析了有序性分子排列促进载流子传输的机理。对比两种工艺制备出相同厚度薄膜的电阻率、吸光度以及荧光光谱。并对有关结果进行探讨。
[Abstract]:Organic electroluminescent devices (OLEDs) have the advantages of lightness, surface luminescence, self-luminescence, flexible bending and transparency, etc. The organic layer of OLED devices has a broad application prospect in the field of lighting and display. The organic layer of OLED devices is an organic chemical material. There are vacuum evaporation, spin coating, inkjet printing, screen printing and so on. The molecules in the organic layers prepared by these processes are disordered, while the carrier transport efficiency is low in the organic films with the molecular disordered arrangement, which has a certain influence on the photoluminescence efficiency of OLED devices. The technology of Langmuir-Blodgetttt. is under the appropriate conditions. The amphiphilic molecules with both hydrophilic head and hydrophobic tail are dispersed on the water surface, and the occupied area on the water surface is gradually compressed to form a monolayer layer, and then transferred to a solid substrate to obtain a molecular ordered arrangement film. Due to the ordered arrangement of molecules, the carrier transport efficiency of the organic luminescent layer prepared by LB film method is increased, thus improving the electro-optic efficiency of OLED devices. At present, some researchers have applied LB film technology to the chemical field to improve the catalytic efficiency by using ordered arrangement of molecules, while others have applied LB film technology to the field of biological semi-permeable film. The application of LB film technology to the preparation of organic layers of OLED devices is rarely reported, and the mechanism of LB films acting in organic layers is rarely reported. In this paper, the preparation principle and technology of the common hole transport material-poly (vinyl carbazolium) PVK in OLED devices by LB film method have been studied. In order to find out the effect of ordered molecular arrangement on optical and electrical properties of LB films, PVK organic films were prepared by LB and spin coating methods, and the PVK film models were established by LB and spin-coating methods. The optical and electrical properties of PVK films prepared by two kinds of processes were tested and compared. The main work of this paper is as follows: 1. The preparation model of PVK organic thin films by LB method has been established. It includes the uniformity and stability of toluene solution with PVK on the surface of ultrapure water. The hydrophilic mechanism of the substrate and the interaction mechanism between the film and the substrate and between the film and the film are analyzed. Finally, the effect of ordered arrangement of molecules on carrier transport is explained theoretically. 2. The effects of different hydrophilic processes on the transmittance and surface resistance of PVK substrates in LB films are studied. The effect of dispersant ratio on the resistivity and thickness of PVK LB films was studied by using a self-made LB film drawing apparatus. Monolayer to multilayer PVK LB thin films were prepared and the film thickness, UV-Vis absorption spectrum, fluorescence spectrum and resistivity were measured. 3. According to the rule of spin coating, the data obtained by changing different concentration and rotational speed in spin-coating experiment were obtained. The spin coating model of PVK was established. PVK thin films of the same thickness as LB films were prepared. The mechanism of ordered molecular arrangement to promote carrier transport was analyzed by measuring the film thickness, absorbance and fluorescence spectrum. The resistivity, absorbance and fluorescence spectra of the films of the same thickness were obtained by comparing the two processes. The results are discussed.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN383.1

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