A Core-Shell MWCNT-Pt Nanowire Electron Source with Anomalously Long-Term Stable Field Emission

Area of Science:

• Materials Science
• Nanotechnology
• Electron Emission

Background:

• Electron sources are crucial for various applications, but long-term stability, especially under non-ideal conditions, remains a challenge.
• Conventional electron sources often degrade due to oxidation and excessive heating, limiting their operational lifetime.
• Developing robust and stable electron sources is essential for advancing technologies requiring reliable electron emission.

Purpose of the Study:

• To develop a novel hybrid core-shell nanowire structure for a long-term stable electron source.
• To investigate the influence of a platinum (Pt) shell on the stability and performance of multi-walled carbon nanotube (MWCNT) based electron sources.
• To demonstrate the enhanced durability and operational capabilities of the Pt/MWCNT electron source under challenging conditions.

Main Methods:

• Fabrication of a Pt/MWCNT hybrid nanowire using field-emission-induced deposition (FEID).
• In situ characterization and testing within a scanning electron microscope (SEM) equipped with nanorobotic manipulators (NRMs).
• In situ fatigue testing at high current intensity (500 nA) and relatively high pressure (3.6×10-3 Pa).

Main Results:

• The Pt/MWCNT hybrid nanowire electron source exhibited a lifetime hundreds of times longer than bare MWCNTs.
• Continuous operation for up to 48 hours was achieved without significant changes in structure or emission current.
• The Pt shell effectively shielded the MWCNT from oxygen and reduced heating, attributed to work function lowering.

Conclusions:

• The Pt/MWCNT hybrid nanowire represents a significant advancement in stable electron source technology.
• The core-shell structure provides exceptional stability and tolerance to poor working environments.
• This development holds promise for applications demanding reliable and long-lasting electron emission.