Alternative Energy Technology Laboratory, Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India.
Nanoscale Res Lett. 2007 Jun 21;2(7):331-6. doi: 10.1007/s11671-007-9067-3.
Multi-walled carbon nanotubes (MWNT) have been synthesized by chemical vapour decomposition (CVD) of acetylene over Rare Earth (RE) based AB2(DyNi2) alloy hydride catalyst. The as-grown carbon nanotubes were purified by acid and heat treatments and characterized using powder X-ray diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy, Thermo Gravimetric Analysis and Raman Spectroscopy. Fully carbon based field emitters have been fabricated by spin coating a solutions of both as-grown and purified MWNT and dichloro ethane (DCE) over carbon paper with and without graphitized layer. The use of graphitized carbon paper as substrate opens several new possibilities for carbon nanotube (CNT) field emitters, as the presence of the graphitic layer provides strong adhesion between the nanotubes and carbon paper and reduces contact resistance. The field emission characteristics have been studied using an indigenously fabricated set up and the results are discussed. CNT field emitter prepared by spin coating of the purified MWNT-DCE solution over graphitized carbon paper shows excellent emission properties with a fairly stable emission current over a period of 4 h. Analysis of the field emission characteristics based on the Fowler-Nordheim (FN) theory reveals current saturation effects at high applied fields for all the samples.
多壁碳纳米管 (MWNT) 通过乙炔在基于稀土 (RE) 的 AB2(DyNi2) 合金氢化物催化剂上的化学气相分解 (CVD) 合成。生长的碳纳米管通过酸和热处理进行纯化，并使用粉末 X 射线衍射、扫描电子显微镜、透射电子显微镜、热重分析和拉曼光谱进行表征。通过在碳纸上旋涂生长的和纯化的 MWNT 以及二氯乙烷 (DCE) 的溶液，制备了全碳场发射器，有和没有石墨化层。使用石墨化碳纸作为基底为碳纳米管 (CNT) 场发射器提供了多种新的可能性，因为石墨层的存在提供了纳米管和碳纸之间的强附着力并降低了接触电阻。使用自制的装置研究了场发射特性，并讨论了结果。通过在石墨化碳纸上旋涂纯化的 MWNT-DCE 溶液制备的 CNT 场发射器在 4 小时的时间内表现出优异的发射性能，发射电流相当稳定。基于 Fowler-Nordheim (FN) 理论的场发射特性分析表明，所有样品在高应用场下都存在电流饱和效应。
