Low density of defect states in hydrogenated amorphous carbon thin films grown by plasma-enhanced chemical vapor deposition

K. M. Krishna, H. Ebisu, K. Hagimoto, Yasuhiko Hayashi, T. Soga, T. Jimbo, M. Umeno

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

The density of electronic defect states in most forms of amorphous carbon deposited at room temperature is found so far to be very high (1018-1022 spins cm-3). In this letter, we demonstrate that the radio-frequency plasma-enhanced chemical vapor deposited hydrogenated amorphous carbon (a-C:H) thin film exhibits the lowest spin density of the order of 1016 cm-3, investigated by using electron spin resonance (ESR) spectroscopy, a very promising reproducible result comparable with high-quality a-Si:H. In addition, the optical gap of a-C:H has been tailored between a wide range, 1.8-3.1 eV. The ESR spectra of all the films reveal a single Lorentzian line whose linewidth ΔHpp varies strongly with the optical gap. Also, there is a strong dependence of spin density on the optical gap, and we show that this dependency is a direct result of structural changes due to sp3/sp2 carbon bonding network.

Original languageEnglish
Pages (from-to)294-296
Number of pages3
JournalApplied Physics Letters
Volume78
Issue number3
DOIs
Publication statusPublished - Jan 15 2001
Externally publishedYes

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vapor deposition
carbon
defects
electron paramagnetic resonance
thin films
radio frequencies
vapors
room temperature
electronics
spectroscopy

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Low density of defect states in hydrogenated amorphous carbon thin films grown by plasma-enhanced chemical vapor deposition. / Krishna, K. M.; Ebisu, H.; Hagimoto, K.; Hayashi, Yasuhiko; Soga, T.; Jimbo, T.; Umeno, M.

In: Applied Physics Letters, Vol. 78, No. 3, 15.01.2001, p. 294-296.

Research output: Contribution to journalArticle

Krishna, K. M. ; Ebisu, H. ; Hagimoto, K. ; Hayashi, Yasuhiko ; Soga, T. ; Jimbo, T. ; Umeno, M. / Low density of defect states in hydrogenated amorphous carbon thin films grown by plasma-enhanced chemical vapor deposition. In: Applied Physics Letters. 2001 ; Vol. 78, No. 3. pp. 294-296.
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