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Separation of excitonic and electron-hole processes in metal tungstates

Nagirnyi, V; Kirm, M; Kotlov, A; Lushchik, A and Jönsson, Leif LU (2003) In Journal of Luminescence 102. p.597-603
Abstract
Absorption, reflection and emission polarization spectra of CdWO4 crystals have been studied in the region 3.5-30 eV in order to distinguish the excitonic and electron-hole processes in the vicinity of the band gap. The following parameters have been defined from the Urbach tail study at 6-300 K: E-0 = 5 eV, sigma(0) = 0.31, homega = 70 meV (565 cm(-1)). Excitonic processes have been shown to dominate at excitation of tungstate crystals in the lower part of the conduction band. Excitons are formed due to the transitions into the tungstate W5d states hybridized with O6p and possess a very strong tendency for self-trapping. Free electrons and holes can be created at the energies 1-2 eV (depending on the crystal) higher than the bottom of the... (More)
Absorption, reflection and emission polarization spectra of CdWO4 crystals have been studied in the region 3.5-30 eV in order to distinguish the excitonic and electron-hole processes in the vicinity of the band gap. The following parameters have been defined from the Urbach tail study at 6-300 K: E-0 = 5 eV, sigma(0) = 0.31, homega = 70 meV (565 cm(-1)). Excitonic processes have been shown to dominate at excitation of tungstate crystals in the lower part of the conduction band. Excitons are formed due to the transitions into the tungstate W5d states hybridized with O6p and possess a very strong tendency for self-trapping. Free electrons and holes can be created at the energies 1-2 eV (depending on the crystal) higher than the bottom of the conduction band due to the transitions into cationic states. (C) 2003 Elsevier Science B.V. All rights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
band structure, urbach rule, tungstates, absorption
in
Journal of Luminescence
volume
102
pages
597 - 603
publisher
Elsevier
external identifiers
  • wos:000182376000109
  • scopus:0037402211
ISSN
0022-2313
DOI
10.1016/S0022-2313(02)00596-3
language
English
LU publication?
yes
id
5c033e2b-a320-459c-98b2-0605ef6f1d2d (old id 313011)
date added to LUP
2007-09-18 14:27:42
date last changed
2018-09-30 04:08:32
@article{5c033e2b-a320-459c-98b2-0605ef6f1d2d,
  abstract     = {Absorption, reflection and emission polarization spectra of CdWO4 crystals have been studied in the region 3.5-30 eV in order to distinguish the excitonic and electron-hole processes in the vicinity of the band gap. The following parameters have been defined from the Urbach tail study at 6-300 K: E-0 = 5 eV, sigma(0) = 0.31, homega = 70 meV (565 cm(-1)). Excitonic processes have been shown to dominate at excitation of tungstate crystals in the lower part of the conduction band. Excitons are formed due to the transitions into the tungstate W5d states hybridized with O6p and possess a very strong tendency for self-trapping. Free electrons and holes can be created at the energies 1-2 eV (depending on the crystal) higher than the bottom of the conduction band due to the transitions into cationic states. (C) 2003 Elsevier Science B.V. All rights reserved.},
  author       = {Nagirnyi, V and Kirm, M and Kotlov, A and Lushchik, A and Jönsson, Leif},
  issn         = {0022-2313},
  keyword      = {band structure,urbach rule,tungstates,absorption},
  language     = {eng},
  pages        = {597--603},
  publisher    = {Elsevier},
  series       = {Journal of Luminescence},
  title        = {Separation of excitonic and electron-hole processes in metal tungstates},
  url          = {http://dx.doi.org/10.1016/S0022-2313(02)00596-3},
  volume       = {102},
  year         = {2003},
}