Field emission from self-catalyzed GaAs nanowires

TL;DR

This study demonstrates stable field emission from self-catalyzed GaAs nanowires, analyzing emission characteristics and effects of catalyst droplets, with implications for vacuum electronic devices.

Contribution

First detailed analysis of field emission from self-catalyzed GaAs nanowires, including effects of catalyst droplets and emission from sidewalls.

Findings

Stable emission current up to 10^{-7} A from single nanowire

Field enhancement factor up to 112 at 350 nm distance

Presence of Ga catalyst droplet suppresses tip emission

Abstract

We report observation of field emission from self-catalyzed GaAs nanowires grown on Si (111). The measurements are realized inside a scanning electron microscope chamber with nano-controlled tungsten tip functioning as anode. Experimental data are analyzed in the framework of Fowler-Nordheim theory. We demonstrate stable current up to 10$^{-7}$ A emitted from the tip of single nanowire, with field enhancement factor $\beta$ up to 112 at anode-cathode distance d=350 nm. A linear dependence of $\beta$ on the anode-cathode distance is experimentally found. We also show that the presence of a Ga catalyst droplet suppresses the emission of current from the nanowire tip. This allows detection of field emission from the nanowire sidewalls, which occurs with reduced field enhancement factor and stability. This study further extends the GaAs technology to vacuum electronics applications.