The influence of a dye adsorption solvent of an infrared organic dye (NK-6037) on solar cell performance was investigated in a mesoporous TiO2 dye-sensitized solar cell (DSC). Various types of alcohols and a mixture of ethanol and tertiary-butanol (t-butanol) were applied as dye adsorption solvents. It was confirmed that the species of dye adsorption solvent significantly influences the performance of a DSC. Decreasing the specific dielectric constant of the dye adsorption solvent caused the amount of dye adsorbed on the TiO2 photoelectrode to increase dramatically. It is suggested that the specific dielectric constant of the dye adsorption solvent influences the solvation state of the NK-6037 dye in the solvent, thus determining, for instance, whether the dye is in the monomer state or the aggregate state. Interestingly, solar cell performance was not linearly proportional to the adsorbed amount of dye but a precise optimum amount of adsorbed dye was required for the best performance of the DSC. The optimum amount of adsorbed dye was approximately 5.0×108mol/cm2 and it was obtained by using solvents having a dielectric constant of approximately 18. This condition was realized by 1-butanol, 2-propanol, and a mixture of ethanol and t-butanol with a volume ratio of 7:3. The best efficiency obtained for the DSC was 1.7%, using the optimum amount of the adsorbed infrared dye NK-6037. It is speculated that an excess of dye on the TiO2 photoelectrode accelerates the formation of H-type dye aggregates, resulting in a decrease in short circuit photocurrent (Jsc) by unfavorable side reactions of electron loss. It is demonstrated that dye adsorption solvent selection is the critical factor in obtaining high performance in a DSC

1.
O’Regan
,
B.
, and
Graetzel
,
M.
, 1991, “
A Low-Cost, High-Efficiency Solar Cell Based on Dye-Sensitized Colloidal TiO2 Films
,”
Nature (London)
0028-0836,
353
, pp.
737
740
.
2.
Gratzel
,
M.
, 2004, “
Conversion of Sunlight to Electric Power by Nanocrystalline Dye-Sensitized Solar Cells
,”
J. Photochem. Photobiol., A
1010-6030,
164
, pp.
3
14
.
3.
Chiba
,
Y.
,
Islam
,
A.
,
Watanabe
,
Y.
,
Komiya
,
R.
,
Koide
,
N.
, and
Han
,
L.
, 2006, “
Dye-Sensitized Solar Cells With Conversion Efficiency of 11.1%
,”
Jpn. J. Appl. Phys.
0021-4922,
45
, pp.
L638
L640
.
4.
Kim
,
S.
,
Lee
,
J. K.
,
Kang
,
S. O.
,
Ko
,
J.
,
Yum
,
J. -H.
,
Fantacci
,
S.
,
De Angelis
,
F.
,
Di Censo
,
D.
,
Nazeeruddin
,
Md. K.
, and
Graetzel
,
M.
, 2006, “
Molecular Engineering of Organic Sensitizers for Solar Cell Applications
,”
J. Am. Chem. Soc.
0002-7863,
128
,
16701
16707
.
5.
Ito
,
S.
,
Zakeeruddin
,
S. M.
,
Humphry-Baker
,
R.
,
Liska
,
P.
,
Charvet
,
R.
,
Comte
,
P.
,
Nazeeruddin
,
Md. K.
,
Péchy
,
P.
,
Takata
,
M.
,
Miura
,
H.
,
Uchida
,
S.
, and
Graetzel
,
M.
, 2006, “
High-Efficiency Organic-Dye- Sensitized Solar Cells Controlled by Nanocrystalline-TiO2 Electrode Thickness
,”
Adv. Mater.
0935-9648,
18
, pp.
1202
1205
.
6.
Hara
,
K.
,
Kurashige
,
M.
,
Dan-oh
,
Y.
,
Kasada
,
C.
,
Shinpo
,
A.
,
Suga
,
S.
,
Sayama
,
K.
, and
Arakawa
,
H.
, 2003, “
Design of New Coumarin Dyes Having Thiophene Moieties for Highly Efficient Organic-Dye-Sensitized Solar Cells
,”
New J. Chem.
1144-0546,
27
, pp.
783
785
.
7.
Ono
,
T.
,
Yamaguchi
,
T.
, and
Arakawa
,
H.
, 2009, “
Study on Dye-Sensitized Solar Cell Using Novel Infrared
,”
Sol. Energy Mater. Sol. Cells
0927-0248,
93
, pp.
831
835
.
8.
Argazzi
,
R.
,
Bignozzi
,
C. A.
,
Yang
,
M.
,
Hasselmann
,
G. M.
, and
Meyer
,
G. J.
, 2002, “
Solvatochromic Dye Sensitized Nanocrystalline Solar Cells
,”
Nano Lett.
1530-6984,
2
, pp.
625
628
.
9.
Nazeeruddin
,
Md. K.
,
Humphry-Baker
,
R.
,
Liska
,
P.
, and
Graetzel
,
M.
, 2003, “
Investigation of Sensitizer Adsorption and the Influence of Protons on Current and Voltage of a Dye-Sensitized Nanocrystalline TiO2 Solar Cell
,”
J. Phys. Chem. B
1089-5647,
107
, pp.
8981
8987
.
10.
Barbé
,
C. J.
,
Arendse
,
F.
,
Comte
,
P.
,
Jirousek
,
M.
,
Lenzmann
,
F.
,
Shklover
,
V.
, and
Graetzel
,
M.
, 1997, “
Nanocrystalline Titanium Oxide Electrodes for Photovoltaic Applications
,”
J. Am. Ceram. Soc.
0002-7820,
80
, pp.
3157
3171
.
11.
Wang
,
Z. -S.
,
Kawauchi
,
H.
,
Kashima
,
T.
, and
Arakawa
,
H.
, 2004, “
Significant Influence of TiO2 Photoelectrode Morphology on the Energy Conversion Efficiency of N719 Dye-Sensitized Solar Cell
,”
Coord. Chem. Rev.
0010-8545,
248
, pp.
1381
1389
.
12.
Sayama
,
K.
,
Tukagoshi
,
T.
,
Mori
,
T.
,
Hara
,
K.
,
Ohga
,
Y.
,
Shinpo
,
A.
,
Abe
,
Y.
,
Suga
,
S.
, and
Arakawa
,
H.
, 2003, “
Efficient Sensitization of Nanocrystalline TiO2 Films With Cyanine and Merocyanine Organic Dyes
,”
Sol. Energy Mater. Sol. Cells
0927-0248,
80
, pp.
47
71
.
13.
Hara
,
K.
,
Dan-oh
,
Y.
,
Kasada
,
C.
,
Ohga
,
Y.
,
Shinpo
,
A.
,
Suga
,
S.
,
Sayama
,
K.
, and
Arakawa
,
H.
, 2004, “
Effect of Additives on the Photovoltaic Performance of Coumarin-Dye-Sensitized Nanocrystalline TiO2 Solar Cells
,”
Langmuir
0743-7463,
20
, pp.
4205
4210
.
14.
Kurashige
,
Y.
,
Nakajima
,
T.
,
Kurashige
,
S.
,
Hirao
,
K.
, and
Nishikitani
,
Y.
, 2007, “
Theoretical Investigation of the Excited States of Coumarin Dyes for Dye-Sensitized Solar Cells
,”
J. Phys. Chem. A
1089-5639,
111
, pp.
5544
5548
.
15.
Caspar
,
J. V.
, and
Meyer
,
T. J.
, 1983, “
Photochemistry of tris(2,2′-bipyridine)ruthenium(2+) ion (Ru(bpy)32+). Solvent Effects
,”
J. Am. Chem. Soc.
0002-7863,
105
, pp.
5583
5590
.
16.
Janssens
,
G.
,
Tochari
,
F.
,
Gerritsen
,
J. W.
,
van Kempen
,
H.
,
Callant
,
P.
,
Deroover
,
G.
, and
Vandenbroucke
,
D.
, 2001, “
Chemical Structure, Aggregate Structure and Optical Properties of Adsorbed Dye Molecuels Investigated by Scanning Tunnelling Microscopy
,”
Chem. Phys. Lett.
0009-2614,
344
, pp.
1
6
.
17.
Sayama
,
K.
,
Tsukagoshi
,
S.
,
Hara
,
K.
,
Ohga
,
Y.
,
Shinpo
,
A.
,
Abe
,
Y.
,
Suga
,
S.
, and
Arakawa
,
H.
, 2002, “
Photoelectrochemical Properties of J Aggregates of Benzothiazole Merocyanine Dyes on a Nanostructured TiO2 Film
,”
J. Phys. Chem. B
1089-5647,
106
, pp.
1363
1371
.
18.
Reichardt
,
C.
, 1988,
Solvents and Solvent Effects in Organic Chemistry
,
2nd ed.
,
Wiley-VCH
,
Weinheim, Germany
.
19.
Weng
,
Y. -X.
,
Li
,
L.
,
Liu
,
Y.
,
Wang
,
L.
, and
Yang
,
G. -Z.
, 2003, “
Surface-Binding Forms of Carboxylic Groups on Nanoparticulate TiO2 Surface Studied by the Interface-Sensitive Transient Triplet-State Molecular Probe
,”
J. Phys. Chem. B
1089-5647,
107
, pp.
4356
4363
.
20.
Kern
,
R.
,
Sastrawan
,
R.
,
Ferber
,
J.
,
Stangl
,
R.
, and
Luter
,
J.
, 2002, “
Modeling and Interpretation of Electrical Impedance Spectra of Dye Solar Cells Operated Under Open-Circuit Conditions
,”
Electrochim. Acta
0013-4686,
47
, pp.
4213
4225
.
21.
Han
,
L.
,
Koide
,
N.
,
Chiba
,
Y.
, and
Mitate
,
T.
, 2004, “
Modeling of an Equivalent Circuit for Dye-Sensitized Solar Cells
,”
Appl. Phys. Lett.
0003-6951,
84
, p.
2433
.
22.
Onsager
,
L.
, 1936, “
Electric Moments of Molecules in Liquids
,”
J. Am. Chem. Soc.
0002-7863,
58
, pp.
1486
1493
.
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