Enhanced and Stable Field Emission from in Situ Nitrogen-Doped Few-Layered Graphene Nanoflakes

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• 作者：Navneet Soin ; Susanta Sinha Roy ; Soumyendu Roy ; Kiran Shankar Hazra ; Devi S. Misra ; Teck H. Lim ; Crispin J. Hetherington ; James A. McLaughlin
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：April 7, 2011
• 年：2011
• 卷：115
• 期：13
• 页码：5366-5372
• 全文大小：976K
• 年卷期：v.115,no.13(April 7, 2011)
• ISSN：1932-7455

文摘

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 (N₂) 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 N₂ plasma-treated FLGs showed significant improvement in field emission characteristics by lowering the turn-on field (defined at 10 渭A/cm²) from 1.94 to 1.0 V/渭m. Accordingly, the field emission current increased from 17 渭A/cm² at 2.16 V/渭m for pristine FLGs to about 103 渭A/cm² at 1.45 V/渭m for N-doped FLGs. Furthermore, N-doped FLG samples retained 94% of the starting current over a period of 10鈥?00 s, during which the fluctuations were of the order of 卤10.7% only. The field emission behavior of pristine and N₂ 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.