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Inter- and intra- component processes essential for interfacial electron transfer dynamics

Yartsev, Arkady LU ; Benko, Gabor LU and Sundström, Villy LU (2004) Meeting Abstracts - 205th Meeting of The Electrochemical Society, MA 2004 01 In Meeting Abstracts p.594-594
Abstract
Interfacial electron transfer is one of the key processes in the novel type of photovoltaic cells-dye sensitized solar cells (DSSC). By means of transient absorption spectroscopy we have studied the dynamics of the initial photo-induced processes in dye-sensitized nano-porous thin films of wide-band gap semiconductor microcrystallines, which represent the main photoactive part of DSSC. In the most efficient combination of dye and semiconductor, RuN3 (Ru(4,4 prime -dicarboxy-2,2 prime -bipyridine)<sub>2</sub>(NCS)<sub>2</sub>) attached to a nanocrystalline TiO<sub>2</sub> film we have resolved two phases of the photo-induced electron injection that occur on distinctly different time scales. The primary... (More)
Interfacial electron transfer is one of the key processes in the novel type of photovoltaic cells-dye sensitized solar cells (DSSC). By means of transient absorption spectroscopy we have studied the dynamics of the initial photo-induced processes in dye-sensitized nano-porous thin films of wide-band gap semiconductor microcrystallines, which represent the main photoactive part of DSSC. In the most efficient combination of dye and semiconductor, RuN3 (Ru(4,4 prime -dicarboxy-2,2 prime -bipyridine)<sub>2</sub>(NCS)<sub>2</sub>) attached to a nanocrystalline TiO<sub>2</sub> film we have resolved two phases of the photo-induced electron injection that occur on distinctly different time scales. The primary electron injection occurs on sub-hundred fs time scale from a non-thermolized excited state of the dye in competition with intra-molecular energy relaxation processes. The rest of the injection proceeds significantly slower from a quasy-thermolized excited state. The dynamics of the slower part of the injection is essentially non-exponential and can be approximated by a three-exponential process with 1,10, and 50 ps time constants. These two stages of electron injection are separated by a "silent" time interval of 0.1-0.5 ps. We believe that these distinct "modes" of electron injection are different not only by the relative energetics and coupling of the donor and acceptor states of the dye and semiconductor respectively but also by essentially different types of intra-molecular excited state dynamics that influence the injection process. This view is supported by our studies of electron injection dynamics in photoactive RuN3 sensitized SnO2 porous film, in TiO<sub>2</sub> films sensitized by a modified RuN3 dye as well as by the results on the RuN3 photo-induced dynamics in solution. (Less)
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author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Electron injection, Energy relaxation, Dye sensitized solar cells (DSSC), Interfacial electron transfer
in
Meeting Abstracts
pages
594 - 594
publisher
Electrochemical Society
conference name
Meeting Abstracts - 205th Meeting of The Electrochemical Society, MA 2004 01
ISSN
1091-8213
language
English
LU publication?
yes
id
03e25989-8b96-477e-81b1-0453074846aa (old id 613986)
date added to LUP
2007-11-29 14:14:00
date last changed
2016-04-16 03:34:11
@inproceedings{03e25989-8b96-477e-81b1-0453074846aa,
  abstract     = {Interfacial electron transfer is one of the key processes in the novel type of photovoltaic cells-dye sensitized solar cells (DSSC). By means of transient absorption spectroscopy we have studied the dynamics of the initial photo-induced processes in dye-sensitized nano-porous thin films of wide-band gap semiconductor microcrystallines, which represent the main photoactive part of DSSC. In the most efficient combination of dye and semiconductor, RuN3 (Ru(4,4 prime -dicarboxy-2,2 prime -bipyridine)&lt;sub&gt;2&lt;/sub&gt;(NCS)&lt;sub&gt;2&lt;/sub&gt;) attached to a nanocrystalline TiO&lt;sub&gt;2&lt;/sub&gt; film we have resolved two phases of the photo-induced electron injection that occur on distinctly different time scales. The primary electron injection occurs on sub-hundred fs time scale from a non-thermolized excited state of the dye in competition with intra-molecular energy relaxation processes. The rest of the injection proceeds significantly slower from a quasy-thermolized excited state. The dynamics of the slower part of the injection is essentially non-exponential and can be approximated by a three-exponential process with 1,10, and 50 ps time constants. These two stages of electron injection are separated by a "silent" time interval of 0.1-0.5 ps. We believe that these distinct "modes" of electron injection are different not only by the relative energetics and coupling of the donor and acceptor states of the dye and semiconductor respectively but also by essentially different types of intra-molecular excited state dynamics that influence the injection process. This view is supported by our studies of electron injection dynamics in photoactive RuN3 sensitized SnO2 porous film, in TiO&lt;sub&gt;2&lt;/sub&gt; films sensitized by a modified RuN3 dye as well as by the results on the RuN3 photo-induced dynamics in solution.},
  author       = {Yartsev, Arkady and Benko, Gabor and Sundström, Villy},
  booktitle    = {Meeting Abstracts},
  issn         = {1091-8213},
  keyword      = {Electron injection,Energy relaxation,Dye sensitized solar cells (DSSC),Interfacial electron transfer},
  language     = {eng},
  pages        = {594--594},
  publisher    = {Electrochemical Society},
  title        = {Inter- and intra- component processes essential for interfacial electron transfer dynamics},
  year         = {2004},
}