Dynamic Control of Local Field Emission Current from Carbon Nanowalls

TL;DR

This study demonstrates dynamic control of local field emission current from carbon nanowalls using an AC magnetic field or bias, achieving over two orders of magnitude modulation with good stability and controllability.

Contribution

It introduces a method for modulating emission current from carbon nanowalls using magnetic and electrical means, supported by a theoretical model.

Findings

Achieved over two orders of magnitude current modulation.

Demonstrated stable and controllable emission current.

Effective modulation at smaller anode-cathode distances.

Abstract

We report on a systematic study of modulation of the field emission current from carbon nanowalls using a sharp probe as the anode in an ultrahigh vacuum system. Modulation of the local emission current was achieved by either varying the anode-cathode distance (d) with the aid of an AC magnetic field or superimposing a small AC bias on a DC bias during the field emission measurement. Current modulation ratio of over two orders of magnitude was achieved with the modulation becoming more efficient at a smaller d. The experimental results are discussed using the Fowler-Nordheim theory in combination with a simple cantilever model to account for the modulation effect. The experimental results demonstrated good static stability and dynamic controllability of local field emission current from the carbon nanowalls.