10.1021/jp4125364.s001
Andreas F. Bartelt
Andreas F.
Bartelt
Robert Schütz
Robert
Schütz
Christian Strothkämper
Christian
Strothkämper
Joachim Schaff
Joachim
Schaff
Stephan Janzen
Stephan
Janzen
Paja Reisch
Paja
Reisch
Ivo Kastl
Ivo
Kastl
Manuel Ziwritsch
Manuel
Ziwritsch
Rainer Eichberger
Rainer
Eichberger
Gerda Fuhrmann
Gerda
Fuhrmann
David Danner
David
Danner
Lars-Peter Scheller
Lars-Peter
Scheller
Gabriele Nelles
Gabriele
Nelles
Efficient
Electron Injection from Acyloin-Anchored
Semisquarylium Dyes into Colloidal TiO<sub>2</sub> Films for Organic
Dye-Sensitized Solar Cells
American Chemical Society
2014
indoline dye D 131
semisquarylium dye SY 404
TiO 2 surface
electron injection properties
carboxylic acid
nanocrystalline TiO 2
novel acyloin anchor group
TiO 2 semiconductors
Efficient acyloin anchor
carboxylic acid anchor group
semisquarylium dyes
semisquarylium dye DD 1
Efficient Electron Injection
acyloin anchor
TiO 2 conduction band
SY 404 dye
Colloidal TiO 2 Films
IPCE
2014-04-03 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Efficient_Electron_Injection_from_Acyloin_Anchored_Semisquarylium_Dyes_into_Colloidal_TiO_sub_2_sub_Films_for_Organic_Dye_Sensitized_Solar_Cells/2309602
Semisquarylium
dyes use a novel acyloin anchor group to strongly
bind to TiO<sub>2</sub> semiconductors. Efficient acyloin anchor mediated
electron injection into nanocrystalline TiO<sub>2</sub> is demonstrated,
allowing highly efficient dye-sensitized solar cells with IPCEs >
80%. The acyloin anchor can thus be viewed as a true alternative to
the standard carboxylic acid anchor group. The opto-electronic and
electron injection properties of the most basic semisquarylium dye
<b>SY404</b> are compared to the modified semisquarylium
dye <b>DD1</b> and the carboxylic acid anchored indoline dye
<b>D131</b> using a combination of ultrafast and photoemission
spectroscopy. For <b>SY404</b>, ultrafast injection times of
∼50 fs are found despite a small energetic driving force between
dye excited states and TiO<sub>2</sub> conduction band minimum. This
is possible due to the strong electronic coupling of the semisquarylium
dyes to the TiO<sub>2</sub> surface mediated by the acyloin anchor.
For a better overlap with the solar spectrum, the semisquarylium dyes
are modified by substitution with a larger donor moiety (<b>DD1</b>). While for <b>DD1</b> the overall absorption increases, the
injection process slightly slows down; however, it still proves fast
enough for very efficient injection. Compared to the carboxylic acid
anchored indoline dye <b>D131</b>, the <b>SY404</b> dye
injects more than seven times faster despite a ∼150 meV smaller
driving force.