Boosting the Electron Beam Transmittance of Field Emission Cathode Using a Self-Charging Gate

Authors

Dongyang Xiao
Huanhuan Du
Leimeng Sun
Xiaochen Suo
Yurong Wang
Yili Zhang
Shaolin Zhang
Shuangyang Kuang
Fangjing Hu
Liangcheng Tu
Daren Yu
Peiyi Song

Publication Date

1-26-2024

Journal

Nature Communications

Abstract

The gate-type carbon nanotubes cathodes exhibit advantages in long-term stable emission owing to the uniformity of electrical field on the carbon nanotubes, but the gate inevitably reduces the transmittance of electron beam, posing challenges for system stabilities. In this work, we introduce electron beam focusing technique using the self-charging SiN_x/Au/Si gate. The potential of SiN_x is measured to be approximately −60 V quickly after the cathode turning on, the negative potential can be maintained as the emission goes on. The charged surface generates rebounding electrostatic forces on the following electrons, significantly focusing the electron beam on the center of gate hole and allowing them to pass through gate with minimal interceptions. An average transmittance of 96.17% is observed during 550 hours prototype test, the transmittance above 95% is recorded for the cathode current from 2.14 μA to 3.25 mA with the current density up to 17.54 mA cm⁻².

Keywords

Carbon nanotubes and fullerenes, Electronic devices