Fabrication of graphene nanogap with crystallographically matching edges and its electron emission properties

TL;DR

This paper reports the fabrication of graphene nanogaps with matching edges on SiO2 substrates and investigates their electron emission properties, revealing space-charge-limited flow at low biases and Fowler-Nordheim behavior at high voltages.

Contribution

It introduces a method to create graphene nanogaps with crystallographically aligned edges and studies their electron emission characteristics.

Findings

Current-voltage behavior governed by space-charge-limited flow at low biases.

Fowler-Nordheim model fits high-voltage I-V curves.

Electrostatic gating influences electron emission properties.

Abstract

We demonstrate the fabrication of graphene nanogap with crystallographically matching edges on SiO2Si substrates by divulsion. The current-voltage measurement is then performed in a high-vacuum chamber for a graphene nanogap with few hundred nanometers separation. The parallel edges help to build uniform electrical field and allow us to perform electron emission study on individual graphene. It was found that current-voltage characteristics are governed by the space-charge-limited flow of current at low biases while the FN model fits the I-V curves in high voltage regime. We also examined electrostatic gating effect of the vacuum electronic device. Graphene nanogap with atomically parallel edges may open up opportunities for both fundamental and applied research of vacuum nanoelectronics.