Enhanced and Stable Field Emission from in Situ Nitrogen-Doped Few-Layered Graphene Nanoflakes
| Autor: | D. S. Misra, Susanta Sinha Roy, Navneet Soin, Kiran Shankar Hazra, C. J. D. Hetherington, Soumyendu Roy, James McLaughlin, Teck H. Lim |
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| Rok vydání: | 2011 |
| Předmět: |
Atoms
Materials science Silicon Analytical chemistry chemistry.chemical_element Chemical vapor deposition Electron cyclotron resonance law.invention symbols.namesake law Arc-Discharge Physical and Theoretical Chemistry Deposition Films Raman-Spectroscopy Graphene Spectra Ion source Surfaces Coatings and Films Electronic Optical and Magnetic Materials Field electron emission Amorphous-Carbon General Energy chemistry Amorphous carbon Multiwalled Carbon Nanotubes symbols Graphite Raman spectroscopy Photoemission |
| Zdroj: | The Journal of Physical Chemistry C. 115:5366-5372 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/jp110476m |
| Popis: | Vertically aligned few-layered graphene (FLG) nanoflakes were synthesized on bare silicon (Si) substrates by a microwave plasma enhanced chemical vapor deposition method. In situ nitrogen (N(2)) plasma treatment was carried out using electron cyclotron resonance plasma, resulting in various nitrogen functionalities being grafted to the FLG surface. Compared with pristine FLGs, the N(2) plasma-treated FLGs showed significant improvement in field emission characteristics by lowering the turn-on field (defined at 10 mu A/cm(2)) from 1.94 to 1.0 V/mu m. Accordingly, the field emission current increased from 17 mu A/cm(2) at 2.16 V/mu m for pristine FLGs to about 103 mu A/cm(2) at 1.45 V/mu m for N-doped FLGs. Furthermore, N-doped FLG samples retained 94% of the starting current over a period of 10 000 s, during which the fluctuations were of the order of +/- 10.7% only. The field emission behavior of pristine and N(2) plasma-treated FLGs is explained in terms of change in the effective microstructure as well as a reduction in the work function as probed by X-ray photoelectron valence band spectroscopy. |
| Databáze: | OpenAIRE |
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