Berlin 2005 – scientific programme

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VA: Vakuumphysik und Vakuumtechnik

VA 3: Vakuumverfahren und Komponenten 1

VA 3.1: Invited Talk

Monday, March 7, 2005, 14:00–14:30, TU E20

Gated Electron Source with CNT Field Emitter for Vacuum Triode Application — •Wolfram Knapp and Detlef Schleußner — Otto-von-Guericke-Universität Magdeburg, Abteilung Vakuumphysik, Universitätsplatz 2, D-39106 Magdeburg

One main topic of our current investigations is the development of a micro electron source based on a CNT field emitter with an emission current control gate for vacuum microelectronic devices with triode structure. Our low-cost gated micro electron source consists of CNT field-emitter cathode, insulation spacer (thickness in the range of 25 µm - 60 µm), and metal micro-grids as gate. In correspondence with international studies the high current long-term electron-emission stability of carbon nanotube field emitters indicates excellent and reproducible emission properties (after conditioning). But the fabrication of gated electron sources with CNT field emitter is technologically difficult. In our contribution we discuss the influence of different electron-source parameters on electron-emission properties (triode curves, electron transmission) and long-term stability. The advantages of our gated electron source with CNT field emitter are anode currents of about 1 mA and gate voltages below 100 V for regulation of emission current. Therefore, many vacuum electronic applications are possible for this current range by substitution of thermionic cathodes.