AVS 52nd International Symposium
    Nanometer-Scale Science and Technology Thursday Sessions
       Session NS-ThM

Paper NS-ThM3
Stable Electron Emission from a Multi-Wall Carbon Nanotube in Low Vacuum

Thursday, November 3, 2005, 9:00 am, Room 210

Session: Nanotube-based Devices
Presenter: H. Suga, Nihon University, Japan
Authors: H. Suga, Nihon University, Japan
H. Abe, National Institute of Advanced Industrial Science and Technology (AIST), Japan
M. Tanaka, National Institute of Advanced Industrial Science and Technology (AIST), Japan
T. Ohno, Technex Lab Co., Japan
Y. Nishioka, Nihon University, Japan
H. Tokumoto, AIST, Japan
T. Shimizu, AIST, Japan
Correspondent: Click to Email
Carbon nanotubes have been studied intensively in order to realize functional devices utilizing their unique electrical and mechanical properties. Then we have tried to fabricate the electron emitter using a multi-wall carbon nanotube (MWNT). Electrons are usually emitted applying several kilo volts to tungsten tip apex in ultra high vacuum. Therefore it is necessary to prepare high voltage power supply and expensive vacuum pumps like ion pumps. Then the aim of our research is to realize the MWNT electron emitter, by which electrons can be extracted at voltages lower than 500V in low vacuum around 10@super -3@ to 10@super -5@Pa. MWNT electron emitters are fabricated as follows. Tungsten wire and tungsten loop were spot-welded, the wire was electrochemically etched. Then metal nano particles were smeared on the etched tip. Using a specially designed nano-manipulator combined with SEM (Tiny-SEM (W380mmxD350mmxH600mm) by Technex in Japan), a MWNT was attached on the tip apex, at first by the electron beam induced carbon deposition, and, to further assure the bonding between the MWNT and the tip, smeared metal nano particles were melted by heating tungsten loop. Typical length and diameter of the fabricated emitters are about 5µm and 20nm, respectively. Furthermore, in the SEM, the field emission can be carried out and the emitter-anode plane distance can be easily controlled on a micrometer scale, which is typically about 20µm. We measured turn-on field of 5 V/µm which is lower than conventional tungsten emitter in UHV. The emission current of 0.1 to 0.3µA can be attained at applied voltage of 70 to 160V on the same low vacuum condition. The stability of emission current about 1.5% at 0.3µA can be gained. The new way of high stability and the brightness and lifetime evaluation can be discussed in detail in the presentation. @FootnoteText@ hiroshi-suga@@aist.go.jp, tetsuo-shimizu@@aist.go.jp