Amorphous carbon luminescence; excitation and emission in a broad energy range

M. Koós, I. Pócsik, J. Erostyák, A. Buzádi

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Photoluminescence excitation (PLE) spectra at photon energies of 2.47 to 5.63 eV have been obtained for hydrogenated amorphous carbon samples (a-C:H) deposited by radio frequency glow-discharge decomposition of methane at 0 V self bias. A peak in the PLE spectra was observed at ∼ 3.0 eV excitation energy, above which the luminescence intensity slowly decreases with photon energy. Photoluminescence (PL) spectra with a peak at 2.34 eV show similar asymmetric line-shape and peak energy when the excitation photon energy decreases from 5.6 eV to 2.5 eV. The highest photon energy which excites the characteristic PL band is 5.63 eV. Our results demonstrate that light-emitting electron hole pairs remain strongly localized even at excitation energies much higher than the optical gap. A new localization mechanism based on symmetry differences between σ and π bonds is proposed.

Original languageEnglish
Pages (from-to)579-582
Number of pages4
JournalJournal of Non-Crystalline Solids
Volume227-230
Issue numberPART 1
Publication statusPublished - May 1998

Fingerprint

Amorphous carbon
Luminescence
Photoluminescence
Photons
luminescence
Excitation energy
carbon
excitation
photoluminescence
photons
energy
Methane
Glow discharges
Decomposition
Electrons
glow discharges
line shape
radio frequencies
methane
decomposition

Keywords

  • Amorphous carbon
  • Emission
  • Excitation
  • Luminescence

ASJC Scopus subject areas

  • Ceramics and Composites
  • Electronic, Optical and Magnetic Materials

Cite this

Amorphous carbon luminescence; excitation and emission in a broad energy range. / Koós, M.; Pócsik, I.; Erostyák, J.; Buzádi, A.

In: Journal of Non-Crystalline Solids, Vol. 227-230, No. PART 1, 05.1998, p. 579-582.

Research output: Contribution to journalArticle

@article{79dd55f5a9e24543b1b1038aeeba8115,
title = "Amorphous carbon luminescence; excitation and emission in a broad energy range",
abstract = "Photoluminescence excitation (PLE) spectra at photon energies of 2.47 to 5.63 eV have been obtained for hydrogenated amorphous carbon samples (a-C:H) deposited by radio frequency glow-discharge decomposition of methane at 0 V self bias. A peak in the PLE spectra was observed at ∼ 3.0 eV excitation energy, above which the luminescence intensity slowly decreases with photon energy. Photoluminescence (PL) spectra with a peak at 2.34 eV show similar asymmetric line-shape and peak energy when the excitation photon energy decreases from 5.6 eV to 2.5 eV. The highest photon energy which excites the characteristic PL band is 5.63 eV. Our results demonstrate that light-emitting electron hole pairs remain strongly localized even at excitation energies much higher than the optical gap. A new localization mechanism based on symmetry differences between σ and π bonds is proposed.",
keywords = "Amorphous carbon, Emission, Excitation, Luminescence",
author = "M. Ko{\'o}s and I. P{\'o}csik and J. Erosty{\'a}k and A. Buz{\'a}di",
year = "1998",
month = "5",
language = "English",
volume = "227-230",
pages = "579--582",
journal = "Journal of Non-Crystalline Solids",
issn = "0022-3093",
publisher = "Elsevier",
number = "PART 1",

}

TY - JOUR

T1 - Amorphous carbon luminescence; excitation and emission in a broad energy range

AU - Koós, M.

AU - Pócsik, I.

AU - Erostyák, J.

AU - Buzádi, A.

PY - 1998/5

Y1 - 1998/5

N2 - Photoluminescence excitation (PLE) spectra at photon energies of 2.47 to 5.63 eV have been obtained for hydrogenated amorphous carbon samples (a-C:H) deposited by radio frequency glow-discharge decomposition of methane at 0 V self bias. A peak in the PLE spectra was observed at ∼ 3.0 eV excitation energy, above which the luminescence intensity slowly decreases with photon energy. Photoluminescence (PL) spectra with a peak at 2.34 eV show similar asymmetric line-shape and peak energy when the excitation photon energy decreases from 5.6 eV to 2.5 eV. The highest photon energy which excites the characteristic PL band is 5.63 eV. Our results demonstrate that light-emitting electron hole pairs remain strongly localized even at excitation energies much higher than the optical gap. A new localization mechanism based on symmetry differences between σ and π bonds is proposed.

AB - Photoluminescence excitation (PLE) spectra at photon energies of 2.47 to 5.63 eV have been obtained for hydrogenated amorphous carbon samples (a-C:H) deposited by radio frequency glow-discharge decomposition of methane at 0 V self bias. A peak in the PLE spectra was observed at ∼ 3.0 eV excitation energy, above which the luminescence intensity slowly decreases with photon energy. Photoluminescence (PL) spectra with a peak at 2.34 eV show similar asymmetric line-shape and peak energy when the excitation photon energy decreases from 5.6 eV to 2.5 eV. The highest photon energy which excites the characteristic PL band is 5.63 eV. Our results demonstrate that light-emitting electron hole pairs remain strongly localized even at excitation energies much higher than the optical gap. A new localization mechanism based on symmetry differences between σ and π bonds is proposed.

KW - Amorphous carbon

KW - Emission

KW - Excitation

KW - Luminescence

UR - http://www.scopus.com/inward/record.url?scp=0032065127&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032065127&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0032065127

VL - 227-230

SP - 579

EP - 582

JO - Journal of Non-Crystalline Solids

JF - Journal of Non-Crystalline Solids

SN - 0022-3093

IS - PART 1

ER -