Near-Edge X-ray Absorption Fine-Structure Study on Hydrogenated Boron-Doped Ultrananocrystalline Diamond/Amorphous Carbon Composite Films Prepared by Coaxial Arc Plasma Deposition
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2015-01-01 |
| Journal | Transactions of the Materials Research Society of Japan |
| Authors | YÅ«ki Katamune, Satoshi Takeichi, Shinya Ohmagari, Hiroyuki Setoyama, Tsuyoshi Yoshitake |
| Institutions | National Institute of Advanced Industrial Science and Technology, Synchrotron Light Research Institute |
| Citations | 6 |
Abstract
Section titled āAbstractāBoron-doped ultrananocrystalline diamond/amorphous carbon composite films were deposited in the hydrogen pressure range up to 26.7 Pa by coaxial arc plasma deposition with a boron-blended graphite target, and the effects of hydrogenation on the electrical properties and chemical bonding structures of the films were discussed by near-edge X-ray absorption fine structure (NEXAFS) studies. The electrical conductivity decreased with increasing hydrogen pressure. Whereas the nonhydrogenated films showed a semimetallic behavior in the temperature dependence of the electrical conductivity, the hydrogenated films exhibited semiconducting behavior. The boron content estimated from X-ray photoelectron spectroscopic measurements hardly changed with the hydrogen pressure. NEXAFS spectra showed that Ļ* resonance related to sp2-bonded carbon is evidently enhanced with decreasing hydrogen pressure, which is accompanied by a selective etching of sp2 carbon. The results indicate that the carrier transports in UNCD/a-C films are strongly influenced by chemical bonding structure at a-C or grain boundaries.