Ulster University Logo

Ulster Institutional Repository

Metal free, end-opened, selective nitrogen-doped vertically aligned carbon nanotubes by a single step in situ low energy plasma process

Biomedical Sciences Research Institute Computer Science Research Institute Environmental Sciences Research Institute Nanotechnology & Advanced Materials Research Institute

Iyer, GRS and Maguire, PD (2011) Metal free, end-opened, selective nitrogen-doped vertically aligned carbon nanotubes by a single step in situ low energy plasma process. Journal of Materials Chemistry , 21 . pp. 16162-16169. [Journal article]

[img]
Preview
PDF - Accepted Version
451Kb

URL: http://pubs.rsc.org/en/content/articlelanding/2011/jm/c1jm12829a

DOI: 10.1039/C1JM12829A

Abstract

We report a novel single step in situ process of growth and nitrogen-electron cyclotron resonance plasma treatment of vertically aligned multi walled carbon nanotubes (VA-MWCNTs) that leads to concurrent end opening by metal cap removal, nitrogen incorporation and intercalation along with substitution at graphitic sites resulting in n-type electronic doping. Microscopic and spectroscopic evaluations of the nitrogen treated MWCNTs reveal negligible iron content with significant conservation of both structure and alignment. The nitrogen induced electronic change increases distinct π* states as evidenced by Near Edge X-ray Absorption Fine Structure (NEXAFS) and 5 cm−1 downshift of G-band, as observed from Raman spectroscopy, confirm n-type doping. The combined effect of plasma activation (both cavities and surface of the end opened VA-MWCNTs) and n-type doping enhances the field emission performance of the CNTs resulting in high current density (15 mA cm−2) at low applied voltage of 1.5 V μm−1 with low turn on and threshold electric fields (Eto-0.52 and Eth-0.76 V μm−1). This low energy highly controllable plasma has great implications not only in the fabrication of various n-type materials and bio related application but also many other interesting areas for cost effective energy related applications.

Item Type:Journal article
Faculties and Schools:Faculty of Computing & Engineering
Faculty of Computing & Engineering > School of Engineering
Research Institutes and Groups:Engineering Research Institute
Engineering Research Institute > Nanotechnology & Integrated BioEngineering Centre (NIBEC)
ID Code:20738
Deposited By:Professor Paul Maguire
Deposited On:10 Jan 2012 10:11
Last Modified:10 Jan 2012 10:11

Repository Staff Only: item control page