| Summary: | 碩士 === 國立臺灣科技大學 === 電子工程系 === 98 === Carbon nanotubes (CNTs) are promising candidates for cold cathode electron field emitters in the next generation of field emission displays (FED). Some critical properties such as emission current density, stability and uniformity should be guaranteed before they can become commercial products. In order to construct a useful device, this study discusses two methods to modify the field emission performance. One is to set up an optimum arrangement of carbon nanotube arrays, and the other is to coat RuO2 on CNTs. These two methods could reduce the screening effect and elongate the lifetime of CNT based emitters, respectively. The optimum inter-bundle distance was found to be twice their height: the possible cause being that the number density of bundles compared to the screening effect generated a greater effect on field emission. However, a relatively stable emission current was measured from the samples whose inter-bundle distance was triple their height. It is assumed that the reason for this is that the bundles suffered less Joule heating per unit area during the measurement. Moreover, the process of covering the tips of CNTs with a thin film of RuO2 eventually obtained the best matching of these two elements. The study not only enhanced the field emission performance of CNTs, but also extended field emission lifetime by applying a thin film of RuO2 on the CNT tips.
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