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Preparing a Celadonite Electron Source and Estimating Its Brightness
Published on: November 5, 2019
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A high-brightness large-diameter graphene coated point cathode field emission electron source.
Xiuyuan Shao1, Avinash Srinivasan1, Wei Kean Ang1
1Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore.
Nature Communications
|March 31, 2018
Summary
A novel graphene-coated nickel cathode overcomes limitations in cold field emission sources. This advancement enables stable electron emission in high vacuum for electron microscopy and lithography applications.
Area of Science:
- Materials Science
- Surface Science
- Electron Optics
Background:
- Cold field emission (CFE) sources are crucial for electron microscopy and lithography.
- Widespread adoption of CFE sources is hindered by requirements for ultrahigh vacuum (<10-9 torr), poor current stability, and rapid emission decay.
Purpose of the Study:
- To develop a novel cold field emission electron source that addresses the limitations of conventional sources.
- To investigate the performance of a graphene-coated nickel point cathode for improved electron emission characteristics.
Main Methods:
- Fabrication of a cold field emission source utilizing a graphene-coated nickel point cathode.
- Experimental evaluation of emission stability, operating vacuum conditions, and work function.
- Measurement of reduced brightness and energy spread for various tip radii.
Main Results:
- The graphene-coated nickel cathode operates effectively in high vacuum conditions (>10-8 torr).
- Achieved an ultralow work function of 1.10 ± 0.07 eV.
- Demonstrated stable emission with relatively large tip diameters (micron sizes) and comparable performance to state-of-the-art sources.
Conclusions:
- The graphene-coated nickel cathode represents a significant advancement in cold field emission technology.
- This new source overcomes key challenges, paving the way for broader applications in electron microscopy and lithography.
- The demonstrated stability and performance in less stringent vacuum conditions offer practical advantages for future electron-based technologies.
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