电泳法制备碳纳米管冷阴极及其场发射特性研究

发布时间：2018-02-01 11:43

本文关键词： 碳纳米管场发射电泳冷阴极　出处：《电子科技大学》2011年硕士论文　论文类型：学位论文

【摘要】：平板显示器是电视,电脑,手机以及一些移动终端的一个非常重要的部件。而当前平板显示器主要为LCD和LED,但他们的性能跟CRT还有差距,而随着真空微电子学的发展,FED(场发射平面显示器)的已经成功研制,并在性能上有明显的优势,但工艺复杂,生产成本过高,还未大规模应用。1991碳纳米管被发现,因其具有良好的导电性,较大的长径比,高的机械强度,稳定的化学性质,从而表现出良好的场发射性能,而热CVD(化学气相沉积)法实现了碳纳米管的大规模制备,使得碳纳米管成为FED阴极一个非常好的选择。因而本文一个主要的研究内容就是: 通过电泳的方法来制备FED用碳纳米管薄膜冷阴极,并通过对工艺条件的对比实验来优化电泳实验中电泳液配比,沉积基底,电泳电压,电泳时间等重要参数,来实现电泳沉积的薄膜一个相对较好的场发射性能。在优化结果条件下沉积多壁碳纳米管薄膜的阈值场为3.4v/um,最大电流密度为2mA/cm2,是能够满足FED对电流密度的要求的。为了进一步提高沉积碳纳米管薄膜的场发射性能,我们对沉积的碳纳米管薄膜进行了退火处理,电流处理,等离子体处理等后处理实验,并对处理前后的薄膜做了场发射对比实验,结果表明三种方法都在一定程度上降低了开启场,阈值场,提高了碳纳米管薄膜的场发射性能。相对于直接生长法和丝网印刷法制备碳纳米管薄膜,电泳法的一个优点就是可以很轻松地在曲面上实现电泳沉积。因此,我们可以通过电泳沉积碳纳米管在柱面上,制备曲面型的碳纳米管冷阴极,将可以应用于曲面显示设备和荧光灯上。当前磁控管启动慢,阴极热损耗较大的缺点,冷阴极磁控管将可以克服这两个缺点,而磁控管阴极工作时电子是从其圆柱侧面发射的,如果制备圆柱面结构的场发射阴极将有可能实现冷阴极的磁控管。而本文的一个研究点就是: 在圆柱面上电泳沉积碳纳米管薄膜,将能应用于曲面的显示设备和荧光灯上,也有可能作为磁控管的冷阴极。而为了利用到磁控管阴极的二次电子,便对碳纳米管电泳沉积在磁控管阴极进行了研究。
[Abstract]:Flat panel displays are a very important component of televisions, computers, mobile phones, and some mobile devices. Currently, flat panel displays are mainly LCD and LEDs, but their performance still lags behind the CRT. With the development of vacuum microelectronics, FED( Field Emission plane display) has been successfully developed, and has obvious advantages in performance, but the process is complex and the production cost is too high. No large-scale application of .1991 carbon nanotubes has been found, because of its good electrical conductivity, large aspect ratio, high mechanical strength, stable chemical properties, thus showing good field emission performance. Thermal CVD (Chemical Vapor deposition) method has realized the large-scale preparation of carbon nanotubes, which makes carbon nanotubes become a very good choice for FED cathode. Therefore, one of the main research contents of this paper is: The carbon nanotube thin film cold cathode for FED was prepared by electrophoretic method, and the electrophoretic solution ratio, deposition substrate and electrophoretic voltage were optimized by contrast experiment. Electrophoretic time and other important parameters to achieve the electrophoretic deposition of the film a relatively good field emission performance. Under the optimized conditions the threshold field of multi-walled carbon nanotube film deposition is 3.4 v / um. The maximum current density is 2 Ma / cm 2, which can meet the requirements of FED for current density. In order to further improve the field emission performance of deposited carbon nanotube films, we have carried out annealing, current treatment, plasma treatment and other post-treatment experiments. The results show that the three methods reduce the open field and threshold field to a certain extent and improve the field emission performance of carbon nanotube films. Compared with direct growth method and screen printing method, one of the advantages of electrophoretic method is that electrophoretic deposition on the surface can be easily realized. We can prepare curved carbon nanotubes cold cathode by electrophoretic deposition of carbon nanotubes on the cylinder, which can be used in curved surface display devices and fluorescent lamps. At present, the magnetron starts slowly and the cathode heat loss is large. The cold cathode magnetron can overcome these two shortcomings, and the electrons are emitted from the cylindrical side when the magnetron cathode works. If the field emission cathode with cylindrical structure is prepared, it will be possible to realize the magnetron of the cold cathode. Electrophoretic deposition of carbon nanotube films on a cylindrical surface will be used in curved display devices and fluorescent lamps, and may also be used as a cold cathode of magnetron, and in order to make use of secondary electrons of magnetron cathode. The electrophoretic deposition of carbon nanotubes on magnetron cathode was studied.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TB383.1

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