Abstract
The results of field emission (FE) studies are reported for three different forms of carbon: smooth amorphous carbon (a-C) films with both low and high sp3 content prepared by pulsed-laser deposition (PLD), nanostructured carbon prepared by hot-filament chemical-vapor deposition (HFCVD), and vertically aligned carbon nanofibers (VACNFs). The studies reveal that smooth PLD carbon films are poor field emitters regardless of their sp3 content. Conditioning of the films, which resulted in films' modification, was required to draw FE current and the emission turn-on fields were relatively high. In contrast, HFCVD carbon films exhibit very good FE properties, including low-emission turn-on fields, relatively high emission site density, and excellent durability. Finally, VACNFs also were found to possess quite promising FE properties that compete with those of HFCVD films. We believe that the latter two forms of carbon are among the most promising candidates for use as cold cathodes in commercial devices.
Original language | English |
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Pages (from-to) | 949-956 |
Number of pages | 8 |
Journal | Solid-State Electronics |
Volume | 45 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2001 |
Funding
We are grateful to E.A. Kenik and the SHaRE facility for providing the microscope for SEM measurements. We also thank P.H. Fleming for assistance with sample preparation. This research was conducted at Oak Ridge National Laboratory (ORNL), with support from DARPA/MTO under contract no. 1868HH26X1 and from the ORNL LDRD program. ORNL is managed by UT-Battelle, LLC, for the US Department of Energy under contract no. DE-AC05-00OR22725.
Keywords
- Amorphous carbon
- Carbon nanotubes and nanofibers
- Diamond
- Field emission
- Nanostructure