Lim Yu Dian, Grapov Dmitry, Hu Liangxing, Kong Qinyu, Tay Beng Kang, Labunov Vladimir, Miao Jianmin, Coquet Philippe, Aditya Sheel
Centre for Micro-/Nano-electronics (NOVITAS), School of Electrical and Electronics Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore.
Nanotechnology. 2018 Feb 16;29(7):075205. doi: 10.1088/1361-6528/aaa1bb.
It has been widely reported that carbon nanotubes (CNTs) exhibit superior field emission (FE) properties due to their high aspect ratios and unique structural properties. Among the various types of CNTs, random growth CNTs exhibit promising FE properties due to their reduced inter-tube screening effect. However, growing random growth CNTs on individual catalyst islands often results in spread out CNT bundles, which reduces overall field enhancement. In this study, significant improvement in FE properties in CNT bundles is demonstrated by confining them in microfabricated SiO pits. Growing CNT bundles in narrow (0.5 μm diameter and 2 μm height) SiO pits achieves FE current density of 1-1.4 A cm, which is much higher than for freestanding CNT bundles (76.9 mA cm). From the Fowler Nordheim plots, confined CNT bundles show a higher field enhancement factor. This improvement can be attributed to the reduced bundle diameter by SiO pit confinement, which yields bundles with higher aspect ratios. Combining the obtained outcomes, it can be conclusively summarized that confining CNTs in SiO pits yields higher FE current density due to the higher field enhancement of confined CNTs.
据广泛报道，碳纳米管（CNTs）由于其高纵横比和独特的结构特性而表现出优异的场发射（FE）性能。在各种类型的碳纳米管中，随机生长的碳纳米管由于其降低的管间屏蔽效应而表现出有前景的场发射性能。然而，在单个催化剂岛上生长随机生长的碳纳米管通常会导致碳纳米管束分散，从而降低整体场增强。在本研究中，通过将碳纳米管束限制在微加工的SiO坑中，证明了其场发射性能有显著改善。在狭窄的（直径0.5μm，高度2μm）SiO坑中生长碳纳米管束，实现了1-1.4A/cm的场发射电流密度，这比独立的碳纳米管束（76.9mA/cm）高得多。从福勒-诺德海姆图来看，受限的碳纳米管束显示出更高的场增强因子。这种改善可归因于SiO坑限制导致的束直径减小，从而产生具有更高纵横比的束。综合所得结果，可以得出结论，将碳纳米管限制在SiO坑中会由于受限碳纳米管的更高场增强而产生更高的场发射电流密度。
