Field Emission from Self-Catalyzed GaAs Nanowires

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Gallium arsenide (GaAs) nanowires are promising for electronic applications.
• Field emission is crucial for vacuum electronic devices.
• Understanding emission properties of nanowires is essential for device integration.

Purpose of the Study:

• To investigate field emission properties of self-catalyzed GaAs nanowires grown on Si (111).
• To analyze the influence of the gallium catalyst on field emission.
• To explore the potential of GaAs nanowires in vacuum electronics.

Main Methods:

• Field emission measurements conducted within a scanning electron microscope.
• Utilized a nano-controlled tungsten tip as the anode.
• Analyzed experimental data using Fowler-Nordheim theory.

Main Results:

• Demonstrated stable current up to 10^-7 A from single GaAs nanowire tips.
• Achieved a field enhancement factor (β) up to 112 at a 350 nm anode-cathode distance.
• Observed suppressed emission from the tip in the presence of a Ga catalyst droplet, enabling sidewall emission with reduced β and stability.

Conclusions:

• The presence of a Ga catalyst droplet on GaAs nanowires significantly impacts field emission characteristics.
• Field emission from GaAs nanowire sidewalls can be achieved and characterized.
• GaAs nanowires show potential for vacuum electronics applications, with implications for device design and fabrication.