Field emission from a periodic amorphous silicon pillar array fabricated by modified nanosphere lithography

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Field emission displays and sources require efficient electron emitters.
• Amorphous silicon (a-Si) is a promising material for microelectronic applications.
• Nanostructuring can significantly enhance the field emission properties of materials.

Purpose of the Study:

• To fabricate an array of amorphous silicon nanopillars.
• To investigate the field emission characteristics of these nanopillars.
• To correlate the structure and morphology with field emission performance.

Main Methods:

• Modified nanosphere lithography was employed for fabrication.
• A 70 nm a-Si film was deposited on a crystalline silicon substrate.
• Reactive ion etching was used to create the nanopillar array.

Main Results:

• Low turn-on electrical field of approximately 4.5 V/µm at 10 µA/cm² was observed.
• High current density exceeding 0.2 mA/cm² at 9 V/µm was achieved.
• A field enhancement factor of about 1240 was calculated using the Fowler-Nordheim relationship.

Conclusions:

• The fabricated amorphous silicon nanopillars exhibit excellent field emission properties.
• The observed performance is attributed to the nanopillars' morphology, crystal structure, and high density.
• These results highlight the potential of nanostructured amorphous silicon for field emission devices.