Field Emission Current and Electrical Breakdown by a Pointed Cathode Coated with Carbon-Nano-Tube

Abstract

Feature of field emission current and electrical breakdown was experimentally investigated for very short gap in the range of 0.1μm to 3μm between a pointed cathode coated with Carbon-Nano-Tube (CNT) and a plane anode in vacuum environment. The experimental setup, which consists of the CNT coated cathode, the stainless steel anode and the precise positioning mechanisms actuated by piezoelectric devices, was installed in scanning electron microscope (SEM). The pointed cathode coated with CNT was confirmed to emit electrons by field emission through F-N plots of voltage and current between both electrodes. The minimum voltage required for detecting field emission current decreases with decrease of gap length. The breakdown voltage was higher than the minimum voltage for emission current when the gap length was kept constant.