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

Jani Kallioinen (Corresponding Author), Gabor Benkö, Pasi Myllyperkiö, Leonid Khriachtchev, Björn Skårman, Reine Wallenberg, Markus Tuomikoski, Jouko Korppi-Tommola, Villy Sundström, Arkady P. Yartsev

Research output: Contribution to journalArticleScientificpeer-review

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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.
Original languageEnglish
Pages (from-to)6365 - 6373
Number of pages9
JournalThe Journal of Physical Chemistry B
Volume108
Issue number20
DOIs
Publication statusPublished - 2004
MoE publication typeA1 Journal article-refereed

Fingerprint

Electron injection
preparation
injection
photon density
electrons
Electron beams
Evaporation
Photons
crystallinity
Pumps
Film preparation
evaporation
electron beams
pumps
Kinetics
Air
Acetonitrile
air
Excited states
kinetics

Keywords

  • dye-sensitized solar cell
  • solar cells
  • solar energy
  • electron injection
  • electron transfer

Cite this

Kallioinen, Jani ; Benkö, Gabor ; Myllyperkiö, Pasi ; Khriachtchev, Leonid ; Skårman, Björn ; Wallenberg, Reine ; Tuomikoski, Markus ; Korppi-Tommola, Jouko ; Sundström, Villy ; Yartsev, Arkady P. / Photoinduced ultrafast dynamics of Ru(dcbpy)2(NCS)2-sensitized nanocrystalline TiO2 films : The influence of sample preparation and experimental conditions. In: The Journal of Physical Chemistry B. 2004 ; Vol. 108, No. 20. pp. 6365 - 6373.
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title = "Photoinduced ultrafast dynamics of Ru(dcbpy)2(NCS)2-sensitized nanocrystalline TiO2 films: The influence of sample preparation and experimental conditions",
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.",
keywords = "dye-sensitized solar cell, solar cells, solar energy, electron injection, electron transfer",
author = "Jani Kallioinen and Gabor Benk{\"o} and Pasi Myllyperki{\"o} and Leonid Khriachtchev and Bj{\"o}rn Sk{\aa}rman and Reine Wallenberg and Markus Tuomikoski and Jouko Korppi-Tommola and Villy Sundstr{\"o}m and Yartsev, {Arkady P.}",
year = "2004",
doi = "10.1021/jp037265v",
language = "English",
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pages = "6365 -- 6373",
journal = "The Journal of Physical Chemistry B",
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Kallioinen, J, Benkö, G, Myllyperkiö, P, Khriachtchev, L, Skårman, B, Wallenberg, R, Tuomikoski, M, Korppi-Tommola, J, Sundström, V & Yartsev, AP 2004, 'Photoinduced ultrafast dynamics of Ru(dcbpy)2(NCS)2-sensitized nanocrystalline TiO2 films: The influence of sample preparation and experimental conditions', The Journal of Physical Chemistry B, vol. 108, no. 20, pp. 6365 - 6373. https://doi.org/10.1021/jp037265v

Photoinduced ultrafast dynamics of Ru(dcbpy)2(NCS)2-sensitized nanocrystalline TiO2 films : The influence of sample preparation and experimental conditions. / Kallioinen, Jani (Corresponding Author); Benkö, Gabor; Myllyperkiö, Pasi; Khriachtchev, Leonid; Skårman, Björn; Wallenberg, Reine; Tuomikoski, Markus; Korppi-Tommola, Jouko; Sundström, Villy; Yartsev, Arkady P.

In: The Journal of Physical Chemistry B, Vol. 108, No. 20, 2004, p. 6365 - 6373.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Photoinduced ultrafast dynamics of Ru(dcbpy)2(NCS)2-sensitized nanocrystalline TiO2 films

T2 - The influence of sample preparation and experimental conditions

AU - Kallioinen, Jani

AU - Benkö, Gabor

AU - Myllyperkiö, Pasi

AU - Khriachtchev, Leonid

AU - Skårman, Björn

AU - Wallenberg, Reine

AU - Tuomikoski, Markus

AU - Korppi-Tommola, Jouko

AU - Sundström, Villy

AU - Yartsev, Arkady P.

PY - 2004

Y1 - 2004

N2 - 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.

AB - 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.

KW - dye-sensitized solar cell

KW - solar cells

KW - solar energy

KW - electron injection

KW - electron transfer

U2 - 10.1021/jp037265v

DO - 10.1021/jp037265v

M3 - Article

VL - 108

SP - 6365

EP - 6373

JO - The Journal of Physical Chemistry B

JF - The Journal of Physical Chemistry B

SN - 1520-6106

IS - 20

ER -