Self-assembled growth, microstructure, and field-emission high-performance of ultrathin diamond nanorods.
Self-assembled growth, microstructure, and field-emission high-performance of ultrathin diamond nanorods.
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DOI：
10.1021/nn900167p
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发表时间：
2009-04
期刊：
影响因子：
17.1
通讯作者：
N. Shang;P. Papakonstantinou;Peng Wang;A. Zakharov;U. Palnitkar;I. Lin;M. Chu;A. Stamboulis
中科院分区：
文献类型：
--
作者：
N. Shang;P. Papakonstantinou;Peng Wang;A. Zakharov;U. Palnitkar;I. Lin;M. Chu;A. Stamboulis
报道了在氮气和甲烷混合气体中用微波等离子体辅助化学气相沉积方法生长超薄金刚石纳米棒。DNRs的直径只有2.1 nm，这不仅小于已报道的一维金刚石纳米结构(4-300 nm)，也小于能量稳定的DNRs的理论值。以(111)金刚石/(0002)石墨为取向关系的锥形碳纳米管(CNTs)包覆了超薄的DNR。与金刚石纳米团簇和多层石墨烯纳米线/纳米洋葱一起，DNR自组装成孤立的电子发射球体，具有低阈值、高电流密度(平板显示阈值：2.9V/microm时为10 mA/cm2)场发射性能，优于所有其他常规的场发射性能(Mo和Si针尖等)。和流行的纳米结构(氧化锌纳米结构和纳米金刚石等)场发射体，定向碳纳米管除外。基于非均相自催化气-固过程，提出了DNRs的形成机理。这种基于DNRs的新型集成纳米结构不仅具有理论意义，而且具有作为低功率冷阴极的潜力。
We report the growth of ultrathin diamond nanorods (DNRs) by a microwave plasma assisted chemical vapor deposition method using a mixture gas of nitrogen and methane. DNRs have a diameter as thin as 2.1 nm, which is not only smaller than reported one-dimensional diamond nanostructures (4-300 nm) but also smaller than the theoretical value for energetically stable DNRs. The ultrathin DNR is encapsulated in tapered carbon nanotubes (CNTs) with an orientation relation of (111)diamond//(0002)graphite. Together with diamond nanoclusters and multilayer graphene nanowires/nano-onions, DNRs are self-assembled into isolated electron-emitting spherules and exhibit a low-threshold, high current-density (flat panel display threshold: 10 mA/cm2 at 2.9 V/microm) field emission performance, better than that of all other conventional (Mo and Si tips, etc.) and popular nanostructural (ZnO nanostructure and nanodiamond, etc.) field emitters except for oriented CNTs. The forming mechanism of DNRs is suggested based on a heterogeneous self-catalytic vapor-solid process. This novel DNRs-based integrated nanostructure has not only a theoretical significance but also has a potential for use as low-power cold cathodes.