Tailoring the morphology of carbon nanotube assemblies using microgradients in the catalyst thickness

Yosuke Shiratori, Koji Furuichi, Yoshiko Tsuji, Hisashi Sugime, Suguru Noda*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


In addition to the structural control of individual carbon nanotubes (CNTs), the morphological control of their assemblies is crucial to realize miniaturized CNT devices. Microgradients in the thickness of catalyst are used to enrich the variety of available self-organized morphologies of CNTs. Microtrenches were fabricated in gate/spacer/cathode trilayers using a conventional self-aligned top-down process and catalyst exhibiting a microgradient in its thickness was formed on the cathode by sputter deposition through gate slits. CNTs, including single-walled CNTs, of up to 1μm in length were grown within 5-15 s by chemical vapor deposition. The tendency of thin CNTs to aggregate caused interactions between CNTs with different growth rates, yielding various morphologies dependent on the thickness of the catalyst. The field emission properties of several types of CNT assemblies were evaluated. The ability to produce CNTs with tailored morphologies by engineering the spatial distribution of catalysts will enhance their performance in devices.

Original languageEnglish
Article number095101
JournalJapanese journal of applied physics
Issue number9 PART 1
Publication statusPublished - 2011 Sept
Externally publishedYes

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)


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