Effect of long alkyl chains of aniline donor on the photovoltaic performance of D-π-A zinc porphyrin for dye-sensitized solar cells

Article abstract of DOI:10.1002/jccs.201900158

Three novel dyes of JJ1, JJ2, and JJ6 featured zinc porphyrin as a basic core structure; N, N-alkyl-4-(prop-1-yn-1-yl)aniline as an electron donor linked to meso-10-position; 4-(prop-1-yn-1-yl)benzoic acid as an electron acceptor linked to meso-20-positio

Full text of DOI:10.1002/jccs.201900158

Received: 25 April 2019
Revised: 9 June 2019
Accepted: 12 June 2019
DOI: 10.1002/jccs.201900158
S P E C I A L I S S U E P A P E R
Effect of long alkyl chains of aniline donor on the photovoltaic
performance of D-π-A zinc porphyrin for dye-sensitized solar
cells
Yu-Hsuan Chen | Jie-Jun Liu | Chen-Yu Yeh
Department of Chemistry, Research Center
for Sustainable Energy and Nanotechnology
Abstract
(
RCSEN), and Innovation and Development
Three novel dyes of JJ1, JJ2, and JJ6 featured zinc porphyrin as a basic core
structure; N, N-alkyl-4-(prop-1-yn-1-yl)aniline as an electron donor linked to
meso-10-position; 4-(prop-1-yn-1-yl)benzoic acid as an electron acceptor linked to
meso-20-position; and 2,6-bis(dodecyloxy)phenyl or 2,6-bis(octyloxy)phenyl
respectively linked to meso-5 and meso-15-positions of zinc porphyrin have been
synthesized and used for dye-sensitized solar cells. Porphyrin JJ6 featured the
shortest alkyl group (─C H ) on the donor, whereas JJ2 contained the longest
Center of Sustainable Agriculture (IDCSA),
National Chung Hsing University, Taichung,
Taiwan
Correspondence
Chen-Yu Yeh, Department of Chemistry and
Research Center for Sustainable Energy and
Nanotechnology, National Chung Hsing
University, Taichung 402, Taiwan.
Email: cyyeh@dragon.nchu.edu.tw
4
9
alkyl groups (─C H ), and JJ1 has a medium length of octyl groups. With these
12 25
new porphyrin sensitizers, we observed that JJ6 has 7.55% power conversion effi-
Funding information
Ministry of Science and Technology, Grant/
Award Number: 107-2113-M-005-010-MY3
2
ciency under simulated one-sun illumination (AM 1.5 G, 100 mW/cm ) with
2
JSC = 18.64 mA/cm , V = 0.66 V, and fill factor (FF) = 0.61, which was higher
OC
2
than the other two; JJ1 (7.35%) with JSC = 18.83 mA/cm , V = 0.68 V, and
OC
2
FF = 0.60; and JJ2 (6.33%) with JSC = 15.69 mA/cm , V
= 0.62 V, and
OC
FF = 0.65. The power conversion efficiency of JJ6 and JJ1 were higher than JJ2,
demonstrating that the lengthy alkyl groups on the aniline cause a decrease in effi-
ciency of the devices.
K E Y W O R D S
alkyl chain, dye, solar cells, zinc porphyrin
1
| INTRODUCTION
cells (DSCs) have attracted much attention from scientists
since being first reported by Michael Grätzel and coworkers
[
4]
The depletion of natural resources and the global warming
crisis have come to the forefront because human beings have
been overconsuming the petrochemical energy of Earth since
the industrial revolution occurred in the 19th century. Thus,
environmental protection awareness, development of renew-
able technology, and alternative energy are urgent issues. In
addition to the fossil fuel, common alternative renewable
energy sources, including wind power, marine energy, geo-
thermal energy, hydroelectric energy and solar power, are all
in 1991. For so many advantages of DSCs, such as simple
manufacture, tunable optical properties, colorful and trans-
parent features, and low cost, much exertion has been dedi-
cated to improving the efficiency of DSCs and stability of
the devices, which can be performed by appropriately modi-
[
5–15]
fying the dye structure.
In 2011, porphyrin dye YD2-o-
[
16]
C8
achieved a record-high conversion efficiency of
11.9%, which is better than that of organic dyes and ruthe-
nium dyes. In 2014, the structurally modified zinc porphyrin
dyes GY50 and SM315 were provided with the highest
[1–3]
viable energy and eco-friendly.
Dye-sensitized solar
©
2019 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
J Chin Chem Soc. 2019;1–7.
http://www.jccs.wiley-vch.de
1

2
CHEN ET AL.
power conversion efficiencies (PCEs) of 12.5 and 13.0%,
obtain the desired products JJ1, JJ2, and JJ6 in 24, 25, and
20% yields, respectively. These JJ series dyes are stable in air
and easily soluble in common organic solvents such as
CH Cl , ethanol (EtoH), and tetrahydrofuran (THF).
[
17,18]
respectively.
Therefore, understanding the structure–
property relationship of zinc porphyrin dyes is desirable for
further improvement of the cell performance of DSCs. In
2
2
2016, we reported a series of porphyrin-based sensitizers,
YD22-YD28, and YD24, among which the porphyrin dye
featuring a triarylaminophenylethynyl with long carbon
alkyl groups achieved a PCE of 9.19%. The introduction of
long carbon alkyl groups into triarylamine functional groups
significantly reduces molecular aggregation and contributes
2
.2 | Photophysical and electrochemical
properties
The ultraviolet (UV)–vis absorption spectra for JJ series
dyes in THF solution are displayed in Figure 1 and summa-
rized in Table 1. All these dyes have an intense Soret band
at ca. 455–458 nm and a weak Q band at ca. 658–670 nm;
JJ2 has the best molar absorptivity (ε) at Soret band, which
[19]
to the improved PCE.
Here, we developed and synthe-
sized three zinc porphyrin dyes, JJ1, JJ2, and JJ6. All of
them have zinc porphyrin as a core structure, with N, N-
alkyl-substituted aniline as a donor and benzoic acid as an
anchoring group. Implementation of aryl moieties with
ortho-substituted alkoxy chains to meso-5, 15-positions of
porphyrin ring (Scheme 1). Based on our previous studies,
alkyl chains of the triphenylamine donor at meso-position
5
5
is 4.9 × 10 and 0.7 × 10 M/cm at the Q band. For JJ1 and
JJ6, their molar absorptivity of Soret band and Q band are
5
5
5
2
0
.7 × 10 and 0.8 × 10 M/cm (JJ1) and 2.3 × 10 and
.6 × 10 M/cm (JJ6), respectively. On the other hand, the
5
optical bandgap (E0-0) of JJ2 is slightly larger than JJ1 and
JJ6 (from 1.84 to 1.88 eV), which was measured from the
intersection of emission and absorption spectra in the THF
solution at room temperature, although blue-shifted absorp-
tion at Q band was observed for JJ2 compared to JJ1 and
JJ6. To understand the electrochemical behavior of these
porphyrin dyes, cyclic voltammetry measurements were
can inhibit the electron transfer from TiO conduction band
2
[20,21]
to electrolyte and can lessen dye aggregation.
Here, we
would like to elucidate the effects of the lengths of alkyl
chains attached to the meso-phenyl and donor on their elec-
trochemical, optical, and photovoltaic properties.
taken in THF solution containing ferrocene/ferrocenium
2
2
| RESULTS AND DISCUSSION
.1 | Synthesis and characterizations
+
(Fc/Fc ) as an internal standard with 0.1 M tetrabutylammonium
hexafluorophosphate (TBAPF ) as the supporting electrolyte. As
6
shown in Figure 2 and collected data in Table 1, the potentials
of Ehighest occupied molecular orbital (HOMO) were estimated from E1/2
for their first oxidation potential (EHOMO), +0.97 V for JJ2 that
was anodically shifted as compared to JJ1 and JJ6. The
excited-state oxidation potentials (ELUMO) were calculated
from EHOMO − E0-0, in which E0-0 is the zero–zero excitation
energy calculated from the crossing point of normalized emis-
sion and absorption spectra, respectively, −0.90, − 1.08, and
The synthesis of the push–pull zinc porphyrin dyes with the
donor and acceptor attached to meso-positions via ethynylene
[19,22–24]
bridges has been described earlier.
The synthetic pro-
tocol for these JJ-series dyes were displayed in Scheme 2, the
details of which are described in the Experimental Section.
First, bis-protected, triisopropylsilyl-capped zinc porphyrin
was desilylated by fluoride to obtain bis(ethynyl)-substituted
zinc porphyrin, and was then reacted with N, N-dioctyl-, N,
N-didodecyl-, or N, N-dibutyl-4-iodobenzamide and
−1.09 V for JJ2, JJ1, and JJ6, respectively (Figure 3). The
derivated ELUMO potential for these dyes is all higher than the
4-iodobenzoic acid via Sonogashira cross-coupling reaction to
conduction-band level of TiO , assuring an ample driving
2
[
25–27]
force for electron injection.
the oxidation potential of iodide/triiodide (I /I ) redox cou-
As the E
is lower than
LUMO
−
−
3
ple, this indicates that the effective regeneration of JJ series
dyes in a DSC system is all thermodynamically favorable.
2.3 | Photovoltaic performances
The DSC devices of zinc porphyrin-based dyes JJ1, JJ2,
and JJ6 using iodide/triiodide redox mediators in
THF/C H OH (1:4) were studied. The current–voltage (J-V)
2
5
characteristics of these porphyrin-sensitized devices under
2
simulated one-sun illumination (AM 1.5 G, 100 mW/cm )
were displayed in Figure 4, and corresponding photovoltaic
data were collected and are shown in Table 1. The solar-to-
SCHEME 1 Molecular structures of JJ1, JJ2, and JJ6

CHEN ET AL.
3
SCHEME 2 Synthetic procedure for
JJ1, JJ2, and JJ6. (i) TBAF, THF.
(
ii) 4-iodobenzoic acid, N, N-dioctyl-
-iodobenzamide, cat. AsPh , Pd (dba)
Et N, THF. (iii) 4-iodobenzoic acid, N, N-
didodecyl-4-iodobenzamide, cat. AsPh
Pd (dba) , Et N, THF. (iv) 4-iodobenzoic
acid, N, N-dibutyl-4-iodobenzamide, cat.
AsPh , Pd (dba) , Et N, THF. The
synthesis of compound 1 and compound
4
3
2
3
,
3
3
,
2
3
3
3
2
3
3
2
followed the procedure reported
[
16,22–24]
earlier
electric PCEs of DSC devices with 0.4 mM
chenodeoxycholic acid (CDCA) as a coabsorbent additive
2
were 7.35% for JJ1 (JSC = 18.83 mA/cm , V = 0.68 V,
OC
2
fill factor [FF] = 0.60), 6.33% for JJ2 (JSC = 15.69 mA/cm ,
VOC = 0.62 V, FF = 0.65), and 7.55% for JJ6
2
(
JSC = 18.64 mA/cm , V = 0.66 V, FF = 0.61). The Voc
OC
of the DSCs is decided by the potential difference between
the quasi-Fermi level of the electrons at the TiO film and
2
[
28]
the redox potential of electrolyte.
ves, JJ2 has a lower VOC value and short-circuit current
JSC) than those of JJ1 and JJ6, leading to poorer cell per-
Based on the J-V cur-
(
formance. Most likely, the N, N-dodecyl chains on the ani-
FIGURE 1 UV–vis absorption spectra of zinc porphyrin dyes,
JJ1, JJ2, and JJ6 in THF at 25 C
line donor of JJ2 become aggregated due to hydrophobic
interaction in the ionic medium.
ꢀ
[29]
TABLE 1 Electrochemical, photophysical, and photovoltaic properties of JJ1, JJ2, and JJ6 sensitizers
a
c
d
e
λ
max (ε), nm
Emission
E
0-0
,
E
(V)
HOMO
E
(V)
LUMO
J
SC
V
(V)
OC
Efficiency
(%)
5
b
2
(
10 M/cm)
λ
max, (nm)
(eV)
1.84
1.88
1.85
(mA/cm )
18.83
FF
JJ1 458 (2.7), 670 (0.8)
JJ2 455 (4.9), 659 (0.7)
JJ6 456 (2.3), 668 (0.6)
679
667
677
ꢀ
+0.76
+0.97
+0.76
−1.08
−0.90
−1.09
0.68
0.62
0.66
0.60 7.35
0.65 6.33
0.61 7.55
15.69
18.64
a
Absorptions were measured in THF at 25 C.
Measured in THF at 25 C.
The optical bandgap (E0-0) was measured from the intersection of emission and absorption spectra in THF solution.
6
HOMO was determined in THF containing 0.1 M tetrabutylammonium hexafluorophosphate (TBAPF ) as a supporting electrolyte, which was calibrated with
ferrocene/ferrocenium (Fc/Fc ) as an internal reference and converted to that versus NHE by addition of +0.64 V.
Lowest-unoccupied molecular orbitals (LUMO) were obtained from HOMO and optical bandgap (E0-0) using the formula: LUMO = HOMO − E0-0
b
ꢀ
c
d
E
+
e
.

4
CHEN ET AL.
specified. THF was refluxed with sodium/benzophenone
ketyl to remove water and oxygen. CH Cl was refluxed with
2
2
CaH to dry and was freshly distilled before use. Tetra(n-
2
butyl)ammonium hexafluorophosphate ([(n-Bu) N]PF ) was
4
6
recrystallized from absolute ethanol and further dried under
vacuum for 2 days. Column chromatography was performed
1
using silica gel from Merck (70–230 Mesh ASTM). H NMR
13
and C NMR spectra were recorded on a Varian spectrome-
ter operating at 400 MHz. The emission and UV–visible
absorption spectra were measured using the JASCO FP-6000
spectrophotometer and Varian Cary 50 spectrofluorometer,
respectively. Cyclic voltammetric experiments were deter-
mined with a three-electrode system, combined with CHI
Instrument 750A potentiostat in the present of deoxygenated
FIGURE 2 Cyclic voltammograms of JJ1, JJ2, and JJ6 in THF
ꢀ
2
containing 0.1 M TBAPF
6
at 25 C
THF. The BAS glassy carbon (0.07 cm ) disk was used as
the working electrode; the auxiliary and reference electrodes used
platinum wire and Ag/AgCl (saturated), respectively. Potentials
+
are compared with reference to ferrocene/ferrocenium (Fc/Fc )
at E = +0.63 V versus normal hydrogen electrode (NHE) at
1/2
ꢀ
2
3 C in acetonitrile. Before use, the working electrode was
polished with 0.03 μm aluminum on felt pads (Buehler), soaked
in distilled water, and treated ultrasonically for 3 min. The
current–voltage (J-V) characteristics of these JJ series-sensitized
devices were measured with the one-sun illumination
2
(
AM 1.5 G, 100 mW/cm ) using a 700-W short-arc Xenon lamp
equipped in the solar simulator machine (PEC-S20, Peccell
Technologies, Inc. Yokohama, Japan) associated with the volt-
meter (Keithley 2400C). The light intensity was calibrated by
using a Si-KG3 filtered solar cell as a reference cell.
FIGURE 3 Schematic energy levels of JJ series porphyrin dyes
3.2 | Synthesis of JJ1
To a solution of compound 1 (300 mg, 0.2 mmol) in dry
THF (10 mL) was added tetra(n-butyl)ammonium fluoride
(1 M in THF, 2.5 mL, 8.48 mmol). The solution was stirred
for 30 min at room temperature under N2(g). The mixture
was quenched with water and then extracted with CH Cl .
2
2
The organic layer was dried over Na SO , and the solvent
2
4
was removed by high-vacuum rotovapor. After that, N, N-
dioctyl-4-iodobenzenamine (128 mg, 0.29 mmol) and
4
-iodobenzoic acid (72 mg, 0.29 mmol) were added, cata-
lyzed by tris(dibenzylideneacetone)dipalladium (22.98 mg,
.022 mmol) and triphenylarsine (6.8 mg, 0.022 mmol), and
then injected with dry THF (20 mL) and dry triethylamine
4 mL). Futhermore, after refluxing for 16 hr, the residue
0
FIGURE 4 J-V plots spectra of devices fabricated with JJ
series dyes
(
was purified by column chromatography using silica gel and
CH Cl /CH OH (15/1 vol/vol) as the eluent. Removal of the
solvent under reduced pressure and recrystallization from
2
2
3
3
3
| EXPERIMENTAL
.1 | General information
CH Cl /CH OH produced JJ1 as green crystals (81 mg,
2
2
3
1
Yield 24%). H NMR (400 MHz, CDCl3) δ 9.51 (dd,
J = 8.9, 4.5 Hz, 4H), 8.73 (dd, J = 17.3, 4.4 Hz, 4H), 8.22
(d, J = 7.7 Hz, 2H), 7.94 (d, J = 7.8 Hz, 2H), 7.72 (d,
We purchased all solvents and chemicals from commercial
suppliers and used them without further purification unless

CHEN ET AL.
5
J = 8.7 Hz, 2H), 7.63 (t, J = 8.4 Hz, 2H), 6.95 (d,
J = 8.5 Hz, 4H), 6.68 (d, J = 8.5 Hz, 2H), 3.78 (t,
J = 6.4 Hz, 8H), 1.58 (s, 6H), 1.34–1.14 (m, 22H),
(1 M in THF, 2.5 mL, 8.48 mmol). The solution was stirred
at room temperature for 30 min under N2(g). The mixture
was quenched with water and then extracted with CH Cl .
2
2
0
0
1
1
1
1
.93–0.78 (m, 22H), 0.66 (s, 9H), 0.52 (t, J = 7.3 Hz, 26H),
The organic layer was dried over anhydrous Na SO , and
2 4
13
.38 (s, 9H). C NMR (101 MHz, CDCl3) δ 160.22 (s),
51.94 (s), 150.49 (s), 149.87 (s), 149.69 (d, J = 27.2 Hz),
49.28 (s), 135.84 (s), 135.59 (s), 135.35 (s), 133.00 (s),
31.13 (s), 130.15 (s), 129.68 (s), 123.58 (s), 123.33 (s),
23.08 (s), 114.98 (s), 111.70 (s), 105.44 (s), 68.81 (s), 51.28
the solvent was removed under vacuum. After that, N, N-
dibutyl-4-iodobenzenamine (106 mg, 0.32 mmol) and
4-iodobenzoic acid (86 mg, 0.35 mmol) were added, cata-
lyzed by tris(dibenzylideneacetone)dipalladium (23 mg,
0.025 mmol) and triphenylarsine (8 mg, 0.026 mmol), and
then injected with dry THF (15 mL) and dry triethylamine
(3 mL). Futhermore, after refluxing for 16 hr, the residue
was purified by column chromatography using silica gel and
(
s), 32.03 (s), 31.64 (s), 29.61 (d, J = 18.1 Hz), 28.91 (d,
J = 4.6 Hz), 27.46 (d, J = 14.2 Hz), 25.46 (s), 22.84 (s),
2.51 (s), 14.28 (s), 14.07 (s). high-resolution mass
2
+
spectrometry-electrospray ionization (HRMS-ESI) (m/z) [M]
calcd for C H O N Zn, 1,519.8916, found 1,519.8904.
CH Cl /CH OH (20/1 vol/vol) as the eluent. Removal of the
2 2 3
solvent under reduced pressure and recrystallization from
97 125 6 5
CH Cl /CH OH provided JJ6 as green crystals (20 mg,
2
2
3
1
Yield 20%). H NMR (400 MHz, CDCl3) δ 9.53 (dd,
J = 7.7, 4.5 Hz, 4H), 8.74 (dd, J = 17.4, 4.5 Hz, 4H), 8.24
(d, J = 8.4 Hz, 2H), 7.98 (d, J = 8.1 Hz, 2H), 7.75 (d,
J = 8.7 Hz, 2H), 7.66 (d, J = 8.4 Hz, 2H), 6.97 (d,
J = 8.4 Hz, 4H), 6.71 (d, J = 8.7 Hz, 2H), 3.81 (t,
J = 6.6 Hz, 8H), 3.32 (d, J = 8.0 Hz, 4H), 1.61 (s, 4H), 1.38
(d, J = 7.2 Hz, 4H), 1.23–0.83 (m, 58H), 0.77–0.67 (m,
3
.3 | Synthesis of JJ2
To a solution of compound 2 (300 mg, 0.18 mmol) in dry
state THF (10 mL) was added, obtaining tetra(n-butyl)ammo-
nium fluoride (1 M in THF, 2.5 mL, 8.48 mmol). The solu-
tion was stirred at room temperature for 30 min under N2(g)
The mixture was quenched with water and then extracted with
CH Cl . The organic layer was dried over anhydrous Na SO ,
.
13
2
2
2
4
16H), 0.53 (s, 16H), 0.40 (s, 8H). C NMR (101 MHz,
CDCl3) δ 159.94 (s), 149.52 (s), 149.25 (s), 148.97 (s),
135.63 (s), 135.38 (s), 135.14 (s), 132.76 (s), 130.87 (s),
129.92 (s), 123.34 (s), 123.09 (s), 122.84 (s), 111.39 (s),
105.14 (s), 77.39 (s), 77.07 (s), 76.75 (s), 68.54 (s), 50.73
(s), 31.79 (s), 29.66–28.97 (m), 28.71 (s), 25.22 (s), 22.59
and the solvent was removed under vacuum. After that, N, N-
didodecyl-4-iodobenzenamine (124 mg, 0.22 mmol) and
4
-iodobenzoic acid (55 mg, 0.22 mmol) were added, cata-
lyzed by tris(dibenzylideneacetone)dipalladium (17 mg,
.018 mmol) and triphenylarsine (6.78 mg, 0.019 mmol), and
then injected with dry THF (10 mL) and dry triethylamine
2 mL). Futhermore, after refluxing for 10 hr, the residue was
0
+
(s), 20.32 (s), 14.03 (s). HRMS-ESI (m/z) [M + H] calcd
(
for C105H142O N Zn, 1,633.02461, found 1,633.02473.
6
5
purified by column chromatography using silica gel and
CH Cl /CH OH (20/1 vol/vol) as the eluent. Removal of the
solvent under reduced pressure and recrystallization from
2
2
3
3.5 | Device fabrication
CH Cl /CH OH provided JJ2 as green crystals (88 mg, Yield
All reagents were supplied by commercial resources, and
approximately 99% were purified in the DSC fabrication
process. Besides, all fabricating apparatus and materials
were cleaned with detergent, deionized water, and ethanol
sequentially by supersonication. The complete sandwich-
typed cell was composed of the platinum-deposited counter
electrode and dye-sensitized photoanode and sealed together
2
2
1
3
25%). H NMR (400 MHz, CDCl3) δ 9.53 (dd, J = 8.6,
4.5 Hz, 4H), 8.78 (d, J = 4.4 Hz, 4H), 8.24 (d, J = 8.1 Hz,
2H), 8.13 (d, J = 8.0 Hz, 2H), 7.95 (dd, J = 10.8, 8.4 Hz,
4H), 7.65 (t, J = 8.4 Hz, 2H), 6.96 (d, J = 8.6 Hz, 4H), 4.31
(t, J = 6.5 Hz, 2H), 3.81 (t, J = 6.4 Hz, 9H), 1.82–1.60 (m,
4
H), 1.50–1.16 (m, 21H), 1.17–0.53 (m, 78H), 0.40 (d,
1
3
ꢀ
J = 51.2 Hz, 28H). C NMR (101 MHz, CDCl3) δ 159.85
s), 151.40 (s), 150.65 (d, J = 4.7 Hz), 131.69 (s), 130.98 (s),
by hot melt film (Surlyn, 30 μm) at 125 C. For the details,
(
the photoanode was made by using a cleaned fluorine-doped
tin oxide (FTO) glass (3.1 mm thick, 13 Ω/square, 8% haze)
as substrate and then screen-printing the transparent layer
1
1
29.79 (d, J = 27.9 Hz), 129.36–128.33 (m), 121.07 (s),
15.24 (s), 104.99 (s), 68.43 (s), 65.22 (s), 31.82 (d,
J = 7.7 Hz), 30.15–28.00 (m), 26.02 (s), 25.23 (s), 22.62 (d,
with a TiO
particle size of 20 nm from Eternal Materials
2
J = 4.8 Hz), 14.07 (d, J = 4.5 Hz). ESI-MS (m/z) calcd for
Ltd (Kaohsiung, Taiwan) and scattering layer with a TiO
particle size of 400 nm from CCIC (Osaka, Japan). Then,
2
+
C123H179O N Zn, 1886, found 1887, [M + H] .
6
5
ꢀ
the TiO film was sintered at progressive steps until 500 C
2
under the air flow, and the thickness of the sintered film
was, on average, 10–16 μm determined by using the portable
roughness tester SURFCOM FLEX from ACCRETECH
(Tokyo, Japan). After the thermal post-treatment with
3
.4 | Synthesis of JJ6
To a solution of compound 2 (400 mg, 0.25 mmol) in dry
THF (10 mL) was added tetra(n-butyl)ammonium fluoride

6
CHEN ET AL.
ꢀ
4
0 mM TiCl for half an hour at 70 C and annealing process
Agriculture” from The Featured Areas Research Center Pro-
gram within the framework of the Higher Education Sprout
Project by the Ministry of Education (MOE) in Taiwan.
4
ꢀ
at 450 C for 1 hr, the TiO electrodes were soaked in
.15 mM JJ series dyes solution and half concentration of
2
0
CDCA as an additive in an equal volumetric ratio of THF
and EtOH (vol/vol, 1:4) for 8-hr dye loading. For the photo-
cathode, the platinum (Pt) counter electrode was man-
ufactured by operating the two-step dip-coating process,
interpreted such that the cleaned FTO glass (2.2 mm thick,
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2
8
Ω/square) was subsequently dipping into the surfactant
and H PtCl solution. The Pt counter was sintered for 1 hr at
2
6
ꢀ
3
25 C after rinsing with deionized water and was
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| CONCLUSIONS
This study reported the synthesis and the optical, electro-
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longest alkyl chain on donor and did not improve the PCE
effectively compared to JJ1 and JJ6. Interestingly, JJ2
showed the highest molar absorptivity (ε) at 455 nm for
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2
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tion in the ionic environment. Therefore, lengthening of the
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The authors acknowledge the financial support for this work
from the Ministry of Science and Technology (MOST) in
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Chen-Yu Yeh was born in 1968. He received his BS in
chemistry from National Chung Hsing University
(NCHU) in 1990, his MS from National Taiwan Univer-
sity (NTU) in 1992, and his Ph.D. from Michigan State
University in 1999 under the guidance of professor Chi-
Kwong Chang. After postdoctoral studies at MIT with
Professor Daniel G. Nocera and at NTU with Professor
Shie-Ming Peng, he joined NCHU in 2002, where he is
currently a Professor in Chemistry. His research covers
the synthesis of porphyrins for use in solar cells. He has
been recognized with various awards, including the
BauFamily Award, Academia Sinica Award for Junior
Research Investigators. Chen-Yu Yeh received his BS in
Chemistry (1990) from National Chung-Hsing Univer-
sity, MS in Chemistry (1992) from National Taiwan Uni-
versity and Ph.D. (1999) from Michigan State
University. After postdoctoral research at Massachusetts
Institute of Technology (1999) and National Taiwan Uni-
versity (2000), he moved to National Chung-Hsing Uni-
versity as an Assisted Professor of Chemistry in 2002
and is now a Distinguished Professor. His research activ-
ity has been focused on the design and study of porphy-
rins that can be used as materials for the new generation
of solar cells such as dyesensitized solar cells (DSSC),
organic photovoltaics (OPV), and perovskite solar cells
6
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S. Suga, K. Sayama, H. Sugihara, H. Arakawa, J. Phys. Chem. B
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AUTHOR BIOGRAPHIES
Yu-Hsuan Chen received her BS in Chemistry (2008)
from Soochow University, MS degree in Chemistry
(2010) and Ph.D. (2016) from National Chung-Hsing
(PSC). He is also interested in the synthesis and studies
University. She is now working as a postdoctoral fellow
in Prof. Chen-Yu Yeh's group at National Chung-Hsing
University. During her Ph.D. program, she had worked
on tri-copper clusters to process methane oxidation
which were inspired by Particulate Methane Mono-
oxygenase (pMMO) enzyme. Now, her research interest
focus on the synthesis and application of porphyrin-
based material for solar energy conversion in dye-sensi-
tized solar cells (DSSC) and perovskite solar cells (PSC).
of metalloporphyrins as catalysts for small molecules
activation.
How to cite this article: Chen Y-H, Liu J-J,
Yeh C-Y. Effect of long alkyl chains of aniline donor
on the photovoltaic performance of D-π-A zinc
porphyrin for dye-sensitized solar cells. J Chin Chem
Soc. 2019;1–7. https://doi.org/10.1002/jccs.
Jie-Jun Liu received her BS in Chemistry (2014) from
Fu-Jen Catholic University and MS in Chemistry (2016)
from National Chung-Hsing University. Her research
focused on synthesis and study of porphyrins and applied
in dye-sensitized solar cells (DSSC).
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