有机电致发光二极管的性能改善研究

发布时间：2018-07-17 03:48

【摘要】：有机电致发光器件(Organic Light-Emitting Devices,OLED)由于其驱动电压低、高亮度以及宽视角等优点在显示与固态照明领域(Displays and Solid-state lighting)引起了强烈的关注~([1-3]),越来越多的科研工作者逐渐投入到了OLED器件的研究,并相继取得了许多优异的成果,推动了OLED器件的产业化发展。但就商业化应用来说,OLED器件依然存在一些问题,如对载流子平衡的调控、简化器件结构及光谱稳定性的研究等方面依然有待解决,针对OLED器件的这些问题,本文基于对获得高效稳定的有机电致发光器件进行了研究。(1)采用溶胶-凝胶法(Sol-gel)制备Cu O_x薄膜,引入双空穴注入层Cu O_x/PEDOT:PSS来修饰器件的阳极,并通过对各种空穴注入材料的注入空穴能力进行分析,发现Cu O_x/PEDOT:PSS双空穴注入层不但能够增强电子与空穴的平衡,而且能够有效的降低器件的滚降效应,获得一个高效率稳定的蓝色磷光OLED器件,器件的最大亮度与最大电流效率分别达到17180 cd·m~(-2),28.6 cd·A~(-1)。(2)在空穴传输层TCTA与电子传输层TPBi之间引入磷光染料Ir(ppy)_3的超薄发光层,制备了结构为ITO/Mo O_3(2 nm)/NPB(40 nm)/TCTA(10 nm)/Ir(ppy)_3(x nm)/TPBi(40nm)/Li F(1 nm)/Al(80 nm)的非掺杂磷光有机电致发光器件。通过调控非掺杂发光层的厚度,详细研究了Ir(ppy)_3层厚度对器件性能的影响。实验结果表明,当非掺杂发光层厚度为0.2 nm时,器件的性能最好,器件的亮度、效率和外量子效率分别达到26350 cd·m~(-2),42.9 cd·A~(-1)和12.9%。研究结果表明采用超薄的非掺杂发光层可以简化器件的结构与制备过程,提高OLED器件的效率。(3)在聚合物发光二极管(PLED)中,通过将PFO掺杂到PVK与PBD宽带隙的主体混合物中可以获得一个稳定的纯蓝光发射。从PFO掺杂薄膜的电致发光光谱可以发现,纯PFO器件可以观察到明显的绿光带发射,而PFO掺杂器件则有效的抑制了绿光带的发射。而且通过观察不同退火温度下(从80℃到150℃)PFO掺杂器件的电致发光光谱可以发现,光谱的稳定性及色纯度均提高了。这些结果表明将PFO掺杂到该主体混合物中能够减弱PFO分子的聚集与氧化,是抑制绿光带的一种简单有效的方法。
[Abstract]:Organic Light-Emitting Devices (OLED) has attracted much attention in the field of display and solid-state lighting (Displays and Solid-state lighting) because of its advantages of low driving voltage, high brightness and wide angle of view (Displays and Solid-state lighting). Many excellent results have been achieved, which promote the industrialization of OLED devices. But for commercial applications, there are still some problems in OLED devices, such as the control of the carrier balance, the study of the structure of the device and the stability of the spectrum, and so on. For these problems of OLED devices, this paper is based on the high efficiency and stability. The organic electroluminescent devices were studied. (1) the Cu O_x film was prepared by the sol-gel method (Sol-gel), and the two cavity injection layer Cu O_x/PEDOT:PSS was introduced to modify the anode of the device. By analyzing the injection cavitation capacity of various cavity injection materials, it was found that the Cu O_x/PEDOT:PSS double hole injection layer not only enhanced the electron and the electron hole. The hole balance, and can effectively reduce the roll drop effect of the device, obtain a high efficiency and stable blue phosphorescent OLED device, the maximum luminance and maximum current efficiency of the device reach 17180 CD. M~ (-2), 28.6 CD. A~ (-1). (2) the ultra thin hair of the phosphorescent dye Ir (PPy) _3 is introduced between the hole transport layer TCTA and the electronic transport layer TPBi. A non doped phosphorescent organic electroluminescent device with a structure of ITO/Mo O_3 (2 nm) /NPB (40 nm) /TCTA (10 nm) /Ir (PPy) /Ir (PPy) _3 (PPy) _3 (x nm) was prepared. The effect of the thickness of the non doped luminescent layer on the performance of the device was investigated in detail. The experimental results showed that the thickness of the undoped layer was the thickness of the light layer. For 0.2 nm, the device has the best performance, the device brightness, efficiency and external quantum efficiency are 26350 CD. M~ (-2), 42.9 CD. A~ (-1) and 12.9%. research results show that the use of ultra-thin non doped luminescent layer can simplify the structure and preparation process of the device and improve the efficiency of the OLED device. (3) in polymer light-emitting diode (PLED), PF by the PF O doped into the main mixture of PVK and PBD broadband gap can obtain a stable pure blue light emission. From the electroluminescent spectrum of the PFO doped thin film, it is found that the pure PFO device can observe the obvious emission of green light band, and the PFO doping device effectively inhibits the emission of the green band. And by observing different annealing temperatures (from 80) The electroluminescence spectra of PFO doped PFO devices can be found that the stability and color purity of the spectra are improved. These results show that the incorporation of PFO into the main mixture can weaken the aggregation and oxidation of PFO molecules, which is a simple and effective method to suppress the green band.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN383.1

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