Thomas W. Tombler

The synthesis of massive arrays of monodispersed carbon nanotubes that are self-oriented on patterned porous silicon and plain silicon substrates is reported. The approach involves chemical vapor deposition, catalytic particle size control by substrate design, nanotube positioning by patterning, and nanotube self-assembly for orientation. The mechanisms of nanotube growth and self-orientation are elucidated. The well-ordered nanotubes can be used as electron field emission arrays. Scaling up of the synthesis process should be entirely compatible with the existing semiconductor processes, and should allow the development of nanotube devices integrated into silicon technology.

The electron transport properties of well-contacted individual single-walled carbon nanotubes are investigated in the ballistic regime. Phase coherent transport and electron interference manifest as conductance fluctuations as a function of Fermi energy. Resonance with standing waves in finite-length tubes and localized states due to imperfections are observed for various Fermi energies. Two units of quantum conductance 2G(0) = 4e(2)/h are measured for the first time, corresponding to the maximum conductance limit for ballistic transport in two channels of a nanotube.

Probing the photoelectrical properties of single-walled carbon nanotubes (SWNTs) led to the discovery of photoinduced molecular desorption phenomena in nanotube molecular wires. These phenomena were found to be generic to various molecule–nanotube systems. Photodesorption strongly depends on the wavelength of light, the details of which lead to a fundamental understanding of how light stimulates molecular desorption from nanotubes. The results have important implications to nanotube-based molecular electronics, miniature chemical sensors, and optoelectronic devices.

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTDirected Growth of Free-StandingSingle-Walled Carbon NanotubesAlan M. Cassell, Nathan R. Franklin, Thomas W. Tombler, Emory M. Chan, Jie Han, and Hongjie DaiView Author Information Department of Chemistry, Stanford University Stanford, California 94350 NASA Ames Research Center, M/S T27A-1 Moffett Field, California 94035 Cite this: J. Am. Chem. Soc. 1999, 121, 34, 7975–7976Publication Date (Web):August 10, 1999Publication History Received21 June 1999Published online10 August 1999Published inissue 1 September 1999https://pubs.acs.org/doi/10.1021/ja992083thttps://doi.org/10.1021/ja992083trapid-communicationACS PublicationsCopyright © 1999 American Chemical SocietyRequest reuse permissionsArticle Views1440Altmetric-Citations219LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Carbon nanotubes,Catalysts,Chemical vapor deposition,Materials,Precursors Get e-Alerts