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Photoinduced ultrafast dynamics of Ru(dcbpy)(2)(NCS)(2)-sensitized nanocrystalline TiO2 films: The influence of sample preparation and experimental conditions

Kallioinen, J; Benko, Gabor LU ; Myllyperkio, Pasi LU ; Khriachtchev, L; Skårman, Björn LU ; Wallenberg, Reine LU ; Tuomikoski, M; Korppi-Tommola, J; Sundström, Villy LU and Yartsev, Arkady LU (2004) In The Journal of Physical Chemistry Part B 108(20). p.6365-6373
Abstract
In most of the previous ultrafast electron injection studies of Ru(dcbpy)(2)(NCS)(2)-sensitized nanocrystalline TiO2 films, experimental conditions and sample preparation have been different from study to study and no studies of how the differences affect the observed dynamics have been reported. In the present paper, we have investigated the influence of such modifications. Pump photon density, environment of the sensitized film (solvent and air), and parameters of the film preparation (crystallinity and quality of the film) were varied in a systematic way and the obtained dynamics were compared to that of a well-defined reference sample: Ru(dcbpy)(2)(NCS)(2)-TiO2 in acetonitrile. In some cases, the induced changes in the dynamics were... (More)
In most of the previous ultrafast electron injection studies of Ru(dcbpy)(2)(NCS)(2)-sensitized nanocrystalline TiO2 films, experimental conditions and sample preparation have been different from study to study and no studies of how the differences affect the observed dynamics have been reported. In the present paper, we have investigated the influence of such modifications. Pump photon density, environment of the sensitized film (solvent and air), and parameters of the film preparation (crystallinity and quality of the film) were varied in a systematic way and the obtained dynamics were compared to that of a well-defined reference sample: Ru(dcbpy)(2)(NCS)(2)-TiO2 in acetonitrile. In some cases, the induced changes in the dynamics were uncorrelated to the electron injection process. High pump photon density (not in the linear response region) and exposure of the sensitized film to air altered the picosecond-time- scale kinetics considerably, and the changes were attributed mostly to degradation of the dye. In other cases, changes in the measured kinetics were related to the electron injection processes: reducing the firing temperature of the nanocrystalline film or making the film via electron beam evaporation (EBE) resulted in a decrease of the overall crystallinity of the film, and the electron injection slowed. In the sensitized EBE films, in addition to an increased contribution of triplet excited-state electron injection, a new electron transfer (ET) process with a time constant of 200 fs was observed. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
The Journal of Physical Chemistry Part B
volume
108
issue
20
pages
6365 - 6373
publisher
The American Chemical Society
external identifiers
  • wos:000221455000034
  • pmid:18950123
  • scopus:2642566199
ISSN
1520-5207
DOI
10.1021/jp037265v
language
English
LU publication?
yes
id
22b209dc-b1cc-4bb2-85e6-323a384fcfc4 (old id 139029)
date added to LUP
2007-07-03 13:47:46
date last changed
2017-09-03 04:38:13
@article{22b209dc-b1cc-4bb2-85e6-323a384fcfc4,
  abstract     = {In most of the previous ultrafast electron injection studies of Ru(dcbpy)(2)(NCS)(2)-sensitized nanocrystalline TiO2 films, experimental conditions and sample preparation have been different from study to study and no studies of how the differences affect the observed dynamics have been reported. In the present paper, we have investigated the influence of such modifications. Pump photon density, environment of the sensitized film (solvent and air), and parameters of the film preparation (crystallinity and quality of the film) were varied in a systematic way and the obtained dynamics were compared to that of a well-defined reference sample: Ru(dcbpy)(2)(NCS)(2)-TiO2 in acetonitrile. In some cases, the induced changes in the dynamics were uncorrelated to the electron injection process. High pump photon density (not in the linear response region) and exposure of the sensitized film to air altered the picosecond-time- scale kinetics considerably, and the changes were attributed mostly to degradation of the dye. In other cases, changes in the measured kinetics were related to the electron injection processes: reducing the firing temperature of the nanocrystalline film or making the film via electron beam evaporation (EBE) resulted in a decrease of the overall crystallinity of the film, and the electron injection slowed. In the sensitized EBE films, in addition to an increased contribution of triplet excited-state electron injection, a new electron transfer (ET) process with a time constant of 200 fs was observed.},
  author       = {Kallioinen, J and Benko, Gabor and Myllyperkio, Pasi and Khriachtchev, L and Skårman, Björn and Wallenberg, Reine and Tuomikoski, M and Korppi-Tommola, J and Sundström, Villy and Yartsev, Arkady},
  issn         = {1520-5207},
  language     = {eng},
  number       = {20},
  pages        = {6365--6373},
  publisher    = {The American Chemical Society},
  series       = {The Journal of Physical Chemistry Part B},
  title        = {Photoinduced ultrafast dynamics of Ru(dcbpy)(2)(NCS)(2)-sensitized nanocrystalline TiO2 films: The influence of sample preparation and experimental conditions},
  url          = {http://dx.doi.org/10.1021/jp037265v},
  volume       = {108},
  year         = {2004},
}