Using Anodic Aluminum Oxide (AAO) as a Template to Fabricate Carbon Nanotube Field Emitter Arrays

• Main Authors: Chang Kai Chun, 張凱鈞
• Other Authors: Pan Fu Ming
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/56479953918375812461

碩士 === 國立交通大學 === 材料科學與工程系所 === 94 === For the practical field emission display (FED) applications, growth of vertically aligned carbon nanotubes (CNTs) as field emitters is very essential. However, with the traditional synthesis methods, CNTs usually show poor arrangement and disordered direction. To grow CNTs as field emitters for FED applications, we utilize nanoporous anodic aluminum oxide (AAO) with highly ordered pore channels to template the growth of CNT field emitter arrays. The AAO template is prepared by two-step anodization of the Al film on the silicon substrate. After electro-deposition of the Co catalyst on the bottom of the AAO pore channel, multiwall CNTs were synthesized in electron-cyclotron-resonance chemical-vapor-deposition (ECR-CVD) system using the gas mixture of CH4 and H2. CNTs thus prepared were highly aligned because the nanopore channels of the AAO template constrained the CNTs growth along the axis of the pore channels, and CNTs overgrown out of the pore surface remained in the vertical growth direction due to the applied DC bias and the plasma self-bias under the ECR plasma condition. The growth rate of CNTs in the AAO template by ECR-CVD is considerably low, and therefore, the tube length can be suitably controlled by tuning the growth time. In addition, the CNTs tube number density was found to be a function of the Co electro-deposition time. The number of CNTs extending out of AAO nanopores increases linearly with the Co electro- deposition time. On the contrary, the tube number density of CNTs on the Al film decreases with reducing the Co electro-plating time. The field emission property of CNT arrays was investigated in an electrical measurement system under a vacuum condition of 10-6 torr. The electrical measurement showed that the field emission of the AAO-CNT emitter arrays followed Fowler-Nordheim (F-N) field emission behavior. In this work, the carbon nanotube field emission triode was fabricated by two methods, which will be described in the thesis. With the assistant of the AAO template, the mono-dispersed CNTs array in triode structures showed good alignment and well controlled tube number density. The fabrication methods of the CNT-triode structure used in our research are suitable for large-area substrates. The large-area fabrication capability is essential for the implementation of this AAO-CNT triode structure in the FED technology for industrial purpose.