Field‐Emission Characteristics of Individual Carbon Nanotubes with a Conical Tip: The Validity of the Fowler–Nordheim Theory and Maximum Emission Current

Using the field-emission (FE)-induced evaporation technique, carbon-nanotube (CNT) caps with continuously varying radii from subnanometer to 2.5 nm are obtained on individual CNTs with a conical tip. It is found that 1 nm may be considered as a practical critical radius for the applicability of the Fowler–Nordheim theory for capped CNTs, and the maximum stable FE current is dominated by the CNT cap structure. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.