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Core and valence exciton formation in x-ray absorption, x-ray emission and x-ray excited optical luminescence from passivated Si nanocrystals at the Si L-2,L-3 edge

Siller, L.; Krishnamurthy, S.; Kjeldgaard, Lisbeth LU ; Horrocks, B. R.; Chao, Y.; Houlton, A.; Chakraborty, A. K. and Hunt, M. R. C. (2009) In Journal of Physics: Condensed Matter1990-01-01+01:00 21(9).
Abstract
Resonant inelastic x-ray scattering (RIXS), x-ray absorption spectroscopy and x-ray excited optical luminescence (XEOL) have been used to measure element specific filled and empty electronic states over the Si L-2,L-3 edge of passivated Si nanocrystals of narrow size distribution ( diameter 2.2 +/- 0.4 nm). These techniques have been employed to directly measure absorption and luminescence specific to the local Si nanocrystal core. Profound changes occur in the absorption spectrum of the nanocrystals compared with bulk Si, and new features are observed in the nanocrystal RIXS. Clear signatures of core and valence band exciton formation, promoted by the spatial confinement of electrons and holes within the nanocrystals, are observed,... (More)
Resonant inelastic x-ray scattering (RIXS), x-ray absorption spectroscopy and x-ray excited optical luminescence (XEOL) have been used to measure element specific filled and empty electronic states over the Si L-2,L-3 edge of passivated Si nanocrystals of narrow size distribution ( diameter 2.2 +/- 0.4 nm). These techniques have been employed to directly measure absorption and luminescence specific to the local Si nanocrystal core. Profound changes occur in the absorption spectrum of the nanocrystals compared with bulk Si, and new features are observed in the nanocrystal RIXS. Clear signatures of core and valence band exciton formation, promoted by the spatial confinement of electrons and holes within the nanocrystals, are observed, together with band narrowing due to quantum confinement. XEOL at 12 K shows an extremely sharp feature at the threshold of orange luminescence (i.e., at similar to 1.56 eV ( 792 nm)) which we attribute to recombination of valence excitons, providing a lower limit to the nanocrystal band gap. (Less)
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type
Contribution to journal
publication status
published
subject
in
Journal of Physics: Condensed Matter1990-01-01+01:00
volume
21
issue
9
publisher
IOP Publishing
external identifiers
  • wos:000263414800006
  • scopus:65449172385
ISSN
1361-648X
DOI
10.1088/0953-8984/21/9/095005
language
English
LU publication?
yes
id
d2ec8e7c-54be-4966-9d4e-46b019f832fa (old id 1372142)
date added to LUP
2009-05-08 13:19:36
date last changed
2017-11-12 03:43:25
@article{d2ec8e7c-54be-4966-9d4e-46b019f832fa,
  abstract     = {Resonant inelastic x-ray scattering (RIXS), x-ray absorption spectroscopy and x-ray excited optical luminescence (XEOL) have been used to measure element specific filled and empty electronic states over the Si L-2,L-3 edge of passivated Si nanocrystals of narrow size distribution ( diameter 2.2 +/- 0.4 nm). These techniques have been employed to directly measure absorption and luminescence specific to the local Si nanocrystal core. Profound changes occur in the absorption spectrum of the nanocrystals compared with bulk Si, and new features are observed in the nanocrystal RIXS. Clear signatures of core and valence band exciton formation, promoted by the spatial confinement of electrons and holes within the nanocrystals, are observed, together with band narrowing due to quantum confinement. XEOL at 12 K shows an extremely sharp feature at the threshold of orange luminescence (i.e., at similar to 1.56 eV ( 792 nm)) which we attribute to recombination of valence excitons, providing a lower limit to the nanocrystal band gap.},
  author       = {Siller, L. and Krishnamurthy, S. and Kjeldgaard, Lisbeth and Horrocks, B. R. and Chao, Y. and Houlton, A. and Chakraborty, A. K. and Hunt, M. R. C.},
  issn         = {1361-648X},
  language     = {eng},
  number       = {9},
  publisher    = {IOP Publishing},
  series       = {Journal of Physics: Condensed Matter1990-01-01+01:00},
  title        = {Core and valence exciton formation in x-ray absorption, x-ray emission and x-ray excited optical luminescence from passivated Si nanocrystals at the Si L-2,L-3 edge},
  url          = {http://dx.doi.org/10.1088/0953-8984/21/9/095005},
  volume       = {21},
  year         = {2009},
}