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Field emission from diamond particles studied by scanning field emission microscopy
Akihiko Watanabe1, Masahiro Deguchi, Makoto Kitabatake
1Frontier Carbon Technology Project/JFCC, Center for Advanced Research Projects, 6F, Osaka University, 2-1 Yamada-oka, Suita, 565-0871, Osaka, Japan. nave@cam.hi-ho.ne.jp
Ultramicroscopy
|January 22, 2003
Summary
Diamond particles with negative electron affinity (NEA) exhibit field emission properties. Localized "hot spots" on the diamond surface show significantly higher electron emission, explained by proposed field emission models.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Surface Science
Background:
- Diamond particles (DPs) coated with chemically vapor deposited (CVD) diamond exhibit negative electron affinity (NEA).
- Understanding field emission from nanostructured materials is crucial for advanced electronic devices.
Purpose of the Study:
- To investigate the field emission properties of NEA diamond particles.
- To identify the mechanisms responsible for enhanced electron emission from specific regions on the DP surface.
Main Methods:
- Scanning tunneling microscopy/spectroscopy (STM/STS) for microscopic electrical properties.
- Scanning field emission microscopy (SFEM) for emission current distribution.
- Field emission spectroscopy (FES) for analyzing electron transport.
Main Results:
- DPs exhibit NEA, with field emission currents up to 1mA/cm^2 at 3.5kV/mm.
- Microscopic analysis revealed localized regions with wide-gap, bulk-like diamond properties.
- SFEM identified
- hot spots
- with emission currents orders of magnitude higher than
- normal spots
- .
Conclusions:
- Field emission is localized to specific
- hot spots
- on the DP surface.
- Two models involving electron injection and emission through intrinsic diamond or depletion regions explain
- hot spot
- emission.
- A poorly conducting layer influences electron transport from the electrode to vacuum.