%0 Journal Article
%A Sil, Manik
Chandra
%A Sudhakar, Vediappan
%A Kavungathodi, Munavvar Fairoos Mele
%A Punitharasu, Vellimalai
%A Nithyanandhan, Jayaraj
%D 2017
%T Orthogonally
Functionalized Donor/Acceptor Homo- and
Heterodimeric Dyes for Dye-Sensitized Solar Cells: An Approach to
Introduce Panchromaticity and Control the Charge Recombination
%U https://acs.figshare.com/articles/journal_contribution/Orthogonally_Functionalized_Donor_Acceptor_Homo-_and_Heterodimeric_Dyes_for_Dye-Sensitized_Solar_Cells_An_Approach_to_Introduce_Panchromaticity_and_Control_the_Charge_Recombination/5459227
%R 10.1021/acsami.7b09010.s001
%2 https://ndownloader.figshare.com/files/9440866
%K TiO 2 surface
%K chromophore
%K monomeric D 1
%K π- framework forms
%K attenuated charge recombination
%K TiO 2 film
%K power conversion efficiency
%K PCE
%K Charge Recombination Organic dyes
%K Dye-Sensitized Solar Cells
%K D 2
%K D 1
%K V oc
%K TiO 2
%K DSSC
%K spiroBiProDOT π- spacer
%K J sc
%K FT-IR
%K homodimeric spiro-dye D 1
%X Organic dyes possessing conjugated
π-framework forms closely
packed monolayers on photoanode in dye-sensitized solar cell (DSSC),
because of the limitation to control the orientation and the extend
of intermolecular π–π interaction, self-aggregation
of dyes leads to reduced cell performance. In this report, a series
of homodimeric (D1-D1 and D2-D2) and heterodimeric (D1-D2 and D2-D4) donor/acceptor (D/A) dyes containing spiroBiProDOT
π-spacer were designed and synthesized by utilizing Pd-catalyzed
direct arylation reaction and correlates the device performance with
monomeric dyes (D1 and D2). Both the thiophenes (π-spacer)
of spiroBiProDOT were functionalized with same or different donor
groups which led to homodimeric and heterodimeric chromophores in
a single sensitizer. The homodimeric spiro-dye D1-D1 showed
higher power conversion efficiency (PCE), of 7.6% with a Voc and Jsc of 0.672 V and
16.16 mA/cm2, respectively. On the other hand, the monomeric D1 exhibited a PCE of 3.2% (Voc of 0.64 V and Jsc of 7.2 mA/cm2), which is lower by 2.4 fold compared to
dimeric analogue. The spiro-unit provides flexibility between the
incorporated chromophores to orient on TiO2 due to four
sp3-centers, which arrest the molecular motions after chemisorption.
This study shows a new molecular approach to incorporate two chromophores
in the dimeric dye possessing complementary absorption characteristics
toward panchromatic absorption. The attenuated charge recombination
at TiO2/Dye/redox couple interface in case of D1-D1, owing to better passivation of TiO2 surface, was elucidated
through impedance analysis. The FT-IR spectrum of D1-D1 adsorbed
on TiO2 film indicated both the carboxylic units were involved
in chemisorption which makes strong coupling between dye and TiO2.
%I ACS Publications