有机光电子器件的柔性透明电极的初步研究

发布时间：2018-04-17 20:35

本文选题：银纳米线 + 银网格　；参考：《吉林大学》2017年硕士论文

【摘要】：透明导电电极在有机光电子器件的发展中起着非常重要的作用,比如有机电致发光器件(Organic Light Emitting Diode,OLED)、有机光伏电池(Organic Photovoltaic Cell,OPVC)等。同时柔性透明导电电极的发展也推动着以可穿戴设备为首的下一代柔性显示技术的发展。在透明导电电极的性能表征中,透过率和电导率是所有衡量透明导电电极的性能参数中两个最重要的参数。氧化铟锡(Indium Tin Oxide,ITO)电极为现在应用最广泛的透明导电电极,但是由于铟材料的短缺以及ITO电极制备成本过高,现在越来越多的研究者着手寻找一种合适的ITO替代材料。银纳米线在有机柔性光电子的应用中因为其优良的电学、光学和机械性能被当作最有前景的ITO电极材料的替代材料之一。银纳米线在应用中显示出了高透过率、高导电率和优良的机械性能。但是,银纳米松散的特性以及由于银纳米线之间的空隙导致的绝缘性阻碍了银纳米线性能的进一步提高。因此本文提出在银纳米线上混合金属网格结构来提高银纳米线薄膜的导电性并允许近100%的光传输通过网格中的“漏洞”。本文通过喷墨打印技术打印银网格然后结合银纳米线薄膜来制作混合透明导电电极。通过喷墨打印的银网格连接了银纳米线之间的空隙提高了整个混合电极的导电性,同时银网格固化了松散的银纳米线,加强了纳米线与纳米线之间的连接,提高了整个银纳米线薄膜的机械稳定性。这样使得银纳米线薄膜从硅片上剥离得更加完全从而使混合电极得到一个更加平整的表面。该打印的银网格和银纳米线混合电极的方块电阻低至22.5Ω/□,同时透过率达到了87.5%。这个特性相较于单独银纳米线电极45.7Ω/□的方块电阻有了很大提高,同时与玻璃ITO电极20Ω/□的方块电阻和89%的透过率也非常接近。此外,该电极利用了旋涂和剥离光交联聚合物的方法制备柔性衬底,因此具有非常优良的机械性能和表面平整性。我们还通过将此混合透明导电电极用来作为有机发光器件的阳极来测试该电极的实用性。该OLED器件的亮度最高达到10000cd/m2,同时电流效率最高达到了12 cd/A,另外该器件还表现出了非常优良的柔性特点,该柔性发光器件在弯曲测试半径达到2mm的情况下依然能够保持非常稳定电学特性和光学特性。最后我们得出结论Ag-grid/AgNW混合电极制备的柔性器件的优良性能充分体现了利用喷墨打印银纳米粒子结合银纳米线制成的混合透明电极能够应用于高质量的有机光电子器件的制备。
[Abstract]:Transparent conductive electrodes play an important role in the development of organic photoelectron devices, such as organic Light Emitting devices, organic Photovoltaic cells, organic photovoltaic cells, and so on.At the same time, the development of flexible transparent conductive electrodes also promotes the development of the next generation flexible display technology, led by wearable devices.In the performance characterization of transparent conductive electrode, transmittance and conductivity are the two most important parameters to measure the performance of transparent conductive electrode.Indium tin oxide (Indium Tin oxide) electrode is the most widely used transparent conductive electrode. However, due to the shortage of indium material and the high cost of preparing ITO electrode, more and more researchers are looking for a suitable alternative material for ITO.Silver nanowires are considered as one of the most promising ITO electrode materials for their excellent electrical, optical and mechanical properties in the application of organic flexible photoelectron.Silver nanowires show high transmittance, high conductivity and excellent mechanical properties.However, the loose properties of silver nanowires and the insulation caused by the gap between silver nanowires hinder the further improvement of silver nanowires.Therefore, a new method is proposed to improve the electrical conductivity of silver nanowire films by mixing metal mesh structures on silver nanowires and to allow nearly 100% of optical transmission through the "holes" in the grid.In this paper, the silver grid is printed by inkjet printing technique, and then the silver nanowire film is combined to fabricate the mixed transparent conductive electrode.The gap between the silver nanowires is connected by inkjet printing, and the conductivity of the mixed electrode is improved. Meanwhile, the silver mesh solidifies the loose silver nanowires, which strengthens the connection between the nanowires and nanowires.The mechanical stability of the whole silver nanowire film is improved.This allows the silver nanowire film to be stripped more completely from the silicon wafer, resulting in a smoother surface for the mixed electrode.The printed silver grid and silver nanowire hybrid electrode have a square resistance as low as 22.5 惟 /-and a transmittance of 87.5%.This property is much better than the 45.7 惟 /-block resistance of the silver nanowire electrode alone, and is very close to the glass ITO electrode's 20 惟 /-square resistance and 89% transmittance.In addition, the electrode has excellent mechanical properties and surface smoothness due to the preparation of flexible substrates by spin-coating and peeling of photocrosslinked polymers.We also tested the practicability of the hybrid transparent conductive electrode by using it as an anode for organic luminescent devices.The brightness of the OLED device is up to 10000cdr / m2, and the current efficiency is up to 12cd/ m2.In addition, the device also shows excellent flexibility.The flexible luminescent device can maintain very stable electrical and optical properties even when the bending radius reaches 2mm.Finally, we conclude that the excellent performance of flexible devices fabricated with Ag-grid/AgNW hybrid electrode fully shows that the hybrid transparent electrode made of inkjet printing silver nanoparticles combined with silver nanowires can be used in the preparation of high quality organic optoelectronic devices.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN383.1

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