Surface plasmon-mediated enhanced field electron emission based on metasurfaces with a nano-gap driven by LEDs

Abstract

Vacuum electronic devices have the advantages of no scattering, anti-irradiation, and extreme operating temperatures. With their superiorities, light-assisted field emission can be utilized to drive ultrafast micro-/nano-vacuum electronic devices. However, traditional multiphoton or optical field emission is limited by the access of the lasers with high power and energy. In this Letter, an asymmetric non-semiconductor nanostructure may be applied to reduce cost with a nano-level gas or vacuum channel. We find that the basic LED may be a candidate to enhance the electron emission current by utilizing the multi-stage field enhancement consisting of tip effects and plasmon-based enhancement. By designing a field electron emission device with LEDs in standard atmospheric environment, we realize a 25% increase in field electron emission current at the resonance frequency with the light intensity under W cm−2 and the voltage less than 5 V. By comparing with lasers, simple LEDs are beneficial to increase the scope of applications with low-energy requirements. Meanwhile, the structure paves the way to the application of microelectronic and nano-electronic components in the on-chip electronic devices, such as switches and modulators.