Achieving High-Current Carbon Nanotube Emitters

• Published in: Nano letters Vol. 5; no. 11; pp. 2135 - 2138
• Main Authors: Minoux, Eric, Groening, Oliver, Teo, Kenneth B. K, Dalal, Sharvari H, Gangloff, Laurent, Schnell, Jean-Philippe, Hudanski, Ludovic, Bu, Ian Y. Y, Vincent, Pascal, Legagneux, Pierre, Amaratunga, Gehan A. J, Milne, William I
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.11.2005
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Electronics; Exact sciences and technology; Microelectronic fabrication (materials and surfaces technology); Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Structure of solids and liquids; crystallography; Fowler-Nordheim theory; Electric contacts; Voltage drop; Carbon nanotubes; Field emission; Crystallinity; Nanostructures; Electron field emission; Substrates; Rapid thermal annealing; Electric field effects; IV characteristic; Electric fields; Nanotechnology
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl051397d

When a carbon nanotube emitter is operated at high currents (typically above 1 μA per emitter), a small voltage drop (∼few volts) along its length or at its contact generates a reverse/canceling electric field that causes a saturation-like deviation from the classical Fowler−Nordheim behavior with respect to the applied electric field. We present a correction to the Fowler−Nordheim equation to account for this effect, which is experimentally verified using field emission and contact electrical measurements on individual carbon nanotube emitters. By using rapid thermal annealing to improve both the crystallinity of the carbon nanotubes and their electrical contact to the substrate, it is possible to reduce this voltage drop, allowing very high currents of up to 100 μA to be achieved per emitter with no significant deviation from the classical Fowler−Nordheim behavior.