Synthesis and electrical characterization of n -type carbon nanowalls

Kungen Teii, Shozaburo Shimada, Masahiro Nakashima, Alfred T.H. Chuang

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

Nitrogen-incorporated carbon nanowalls are prepared by microwave plasma-enhanced chemical vapor deposition using acetylene and methane. n -type conduction in the nanowalls is confirmed by Hall- and Seebeck-effect measurements. We show that increasing the amount of C2 radicals by adding Ar enables catalyst-free growth of nanowalls at a high rate up to about 1 μm/min and reduces the deposition temperature (TD) down to around 650 °C. A substrate pretreatment using diamond powder results in a composite of nanowalls and nanocrystalline diamond films, suggesting that the nanowall growth is limited by gas-phase conditions rather than surface conditions. The low conductivity nanowalls for low TD exhibit thermal activation in the Arrhenius plot, indicative of semiconducting conduction, while the high conductivity nanowalls for high TD are almost temperature independent, indicative of quasimetallic conduction. The high conductivity is attributed to a global increase in the s p2 cluster size and crystallinity, which is responsible for increasing delocalization of defect states associated with π bonding and, hence, quasimetallic character.

Original languageEnglish
Article number084303
JournalJournal of Applied Physics
Volume106
Issue number8
DOIs
Publication statusPublished - Nov 10 2009

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conduction
carbon
synthesis
conductivity
low conductivity
Seebeck effect
diamond films
acetylene
pretreatment
Hall effect
crystallinity
methane
plots
diamonds
vapor deposition
activation
vapor phases
microwaves
nitrogen
catalysts

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Synthesis and electrical characterization of n -type carbon nanowalls. / Teii, Kungen; Shimada, Shozaburo; Nakashima, Masahiro; Chuang, Alfred T.H.

In: Journal of Applied Physics, Vol. 106, No. 8, 084303, 10.11.2009.

Research output: Contribution to journalArticle

Teii, Kungen ; Shimada, Shozaburo ; Nakashima, Masahiro ; Chuang, Alfred T.H. / Synthesis and electrical characterization of n -type carbon nanowalls. In: Journal of Applied Physics. 2009 ; Vol. 106, No. 8.
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