AVS 51st International Symposium
    Nanometer-scale Science and Technology Monday Sessions
       Session NS-MoM

Paper NS-MoM7
Field Electron Emission from Aligned Carbon Nanotube Bundles at an Ultra-Low Threshold of 1 V/µm

Monday, November 15, 2004, 10:20 am, Room 213D

Session: Carbon Nanotubes-Electrical Properties
Presenter: K.-Y. Lee, Osaka University, Japan
Authors: K.-Y. Lee, Osaka University, Japan
M. Katayama, Osaka University, Japan
N. Hayashi, Osaka University, Japan
Y. Terao, Osaka University, Japan
T. Miyake, Osaka University, Japan
K. Himuro, Osaka University, Japan
S. Honda, Osaka University, Japan
J.-G. Lee, Osaka University, Japan
T. Hirao, Kochi University of Technology, Japan
H. Mori, Osaka University, Japan
K. Oura, Osaka University, Japan
Correspondent: Click to Email
To realize a practically applicable field electron emitter made of carbon nanotubes (CNTs), it is desirable to enhance the electric field concentration determined by the aspect ratio and number density of the individual CNT. As predicted theoretically, the field emission from an aligned CNT array becomes maximum when the ratio of intertube distance to the height of each individual CNT is about 2. We have succeeded in fabricating an architecture that satisfies such an optimal condition by using pillars of aligned CNT bundles. This provides a promising method of obtaining the optimal ratio of interpillar distance (R) to pillar height (H). Patterns of 50 µm diameter and 250 µm pitch of the Fe(5 nm)/Al(10 nm) multilayer catalyst were fabricated on a Si substrate by photolithography and sputtering. The pillars of aligned CNT bundles were grown on the patterns at 700°C by thermal chemical vapor deposition with C@sub 2@H@sub 2@ under a pressure of 600 Pa. Each pillar was composed of CNTs with a number density of about 10@super 10@ cm@super -2@. To obtain the optimal R/H of 2, the pillar height of about 125 µm was adopted. The pillar array exhibited a striking field emission characteristic. The threshold field needed to produce a current density of 10 mA/cm@super 2@, E@sub th@, was 1.0 V/µm. The obtained E@sub th@ is extremely low compared with those for other materials that have been reported so far. Monitoring the electron field emission by means of a fluorescent screen demonstrated the emission uniformity. More details of the results on field emission characteristics, and SEM, TEM observations of the carbon nonotube bundles will be presented.@footnote 1@ This work was partly supported by the Handai Frontier Research Center, and a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology. @FootnoteText@ @footnote 1@M. Katayama, K.-Y. Lee, S. Honda, T. Hirao, and K. Oura, Jpn. J. Appl. Phys. (in press).