Ethynyl thiophene-appended unsymmetrical zinc porphyrin sensitizers for dye-sensitized solar cells

Reeta, P. Silviya; Giribabu, Lingamallu; Sundaram, S.; Hsu, Min Hung; Kumar, Dinesh; Upadhyaya, Hari M.; Robertson, Neil; Hewat, Tracy

doi:10.1039/c3ra47948j

Cited by 21 publications

(21 citation statements)

References 47 publications

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“…Owing to its resemblance to the natural photosynthetic chlorophyll pigment and relatively easy synthetic manipulations, porphyrin as the primary photoactive molecule has dominated this area of research . Its functions include panchromatic light harvesting through most of the visible part of the solar spectrum and electron transport.…”

Section: Introductionmentioning

confidence: 99%

“…Its functions include panchromatic light harvesting through most of the visible part of the solar spectrum and electron transport. In order to tap UV light of the solar spectrum by using porphyrin‐based sensitizers, one has to introduce an organic molecule that absorbs in this region to achieve broad‐band capture . Such type of systems are not only useful for bio‐mimicking natural photosynthesis but also for designing efficient sensitizers for optoelectronic applications …”

Section: Introductionmentioning

confidence: 99%

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Ultrafast Photoinduced Charge Separation Leading to High‐Energy Radical Ion‐Pairs in Directly Linked Corrole–C₆₀ and Triphenylamine–Corrole‐C₆₀ Donor–Acceptor Conjugates

Sudhakar

Gokulnath

Giribabu

et al. 2015

Chemistry An Asian Journal

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Closely positioned donor-acceptor pairs facilitate electron- and energy-transfer events, relevant to light energy conversion. Here, a triad system TPACor-C60 , possessing a free-base corrole as central unit that linked the energy donor triphenylamine (TPA) at the meso position and an electron acceptor fullerene (C60) at the β-pyrrole position was newly synthesized, as were the component dyads TPA-Cor and Cor-C60. Spectroscopic, electrochemical, and DFT studies confirmed the molecular integrity and existence of a moderate level of intramolecular interactions between the components. Steady-state fluorescence studies showed efficient energy transfer from (1) TPA* to the corrole and subsequent electron transfer from (1) corrole* to fullerene. Further studies involving femtosecond and nanosecond laser flash photolysis confirmed electron transfer to be the quenching mechanism of corrole emission, in which the electron-transfer products, the corrole radical cation (Cor(⋅+) in Cor-C60 and TPA-Cor(⋅+) in TPACor-C60) and fullerene radical anion (C60(⋅-)), could be spectrally characterized. Owing to the close proximity of the donor and acceptor entities in the dyad and triad, the rate of charge separation, kCS , was found to be about 10(11) s(-1), suggesting the occurrence of an ultrafast charge-separation process. Interestingly, although an order of magnitude slower than kCS , the rate of charge recombination, kCR , was also found to be rapid (kCR ≈10(10) s(-1)), and both processes followed the solvent polarity trend DMF>benzonitrile>THF>toluene. The charge-separated species relaxed directly to the ground state in polar solvents while in toluene, formation of (3) corrole* was observed, thus implying that the energy of the charge-separated state in a nonpolar solvent is higher than the energy of (3) corrole* being about 1.52 eV. That is, ultrafast formation of a high-energy charge-separated state in toluene has been achieved in these closely spaced corrole-fullerene donor-acceptor conjugates.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Ultrafast Photoinduced Charge Separation Leading to High‐Energy Radical Ion‐Pairs in Directly Linked Corrole–C₆₀ and Triphenylamine–Corrole‐C₆₀ Donor–Acceptor Conjugates

Sudhakar

Gokulnath

Giribabu

et al. 2015

Chemistry An Asian Journal

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“…It also undergoes two reductions at -0.95, corresponding to the reduction of ancillary bipyridine ligands. The excited oxidation potential of m-HRD-1 is 1.27 V, which is above the conduction band of TiO 2 (41).…”

Section: Electrochemical Propertiesmentioning

confidence: 92%

“…0.28 cm2) preparation was described in our earlier studies. 41,42 Briefly, nanocrystalline TiO 2 films of 8-8.5 μm thickness were deposited onto transparent conducting glass (fluorine-doped stannic oxide layer, sheet resistance of 8-10 Ω/ cm 2 ). Then a scattering layer of ~4 µm thickness of 400 nm anatase TiO 2 particles was deposited by screen-printing method.…”

Section: Dye Cell Preparationmentioning

confidence: 99%

Untitled

2017

MOJSP

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A new extended π-conjugate heteroleptic ruthenium(II) complex (m-HRD-1) that contains a 4,4'-bis-2-(5(3,5-di-tert-butylphenyl)thiophene-2-yl)vinyl)2,2'-bipyridine as ancillary ligand, 4,4'-dicaboxy-2,2'-bipyridine as anchoring group, and two thiocyanate ligands in its molecular structure have been designed, synthesized and characterized by CHN, Mass, 1H-NMR, UV-Vis, and fluorescence spectroscopies as well as cyclic voltammetry. Electrochemical and theoretical studies showed that the LUMO of the sensitizer is above TiO 2 conduction band and the HOMO is below the redox potential of the electrolyte. This new sensitizer was tested in dye-sensitized solar cells using liquid redox couple (I-/I 3-) and its performance was compared to the standard sensitizer N719.

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“…[1][2][3][4][5][6][7] These molecules are great importance in fundamental theoretical researches as well as device applications such as field-effect transistors, 3,[8][9][10][11][12][13][14] solar cells, [15][16][17][18][19][20] lightemitting diodes. [21][22][23][24] PAH derivatives have various structural isomers based on the differences in positions of condensed benzene rings.…”

Section: Introductionmentioning

confidence: 99%

Synthetic Control of Photophysical Process and Circularly Polarized Luminescence of [5]Carbohelicene Derivatives Substituted by Maleimide Units

et al. 2016

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A series of [5]carbohelicene derivatives substituted by electron-withdrawing maleimide and electron-donating methoxy such as maleimide-substituted [5]carbohelicene (HeliIm), and methoxy-substituted HeliIm (MeO-HeliIm) were newly designed and synthesized to examine the electrochemical properties, excited-state dynamic and circularly polarized luminescence (CPL). First, electrochemical measurements and DFT calculations of [5]carbohelicene derivatives were performed by comparing with the structural isomers: picene derivatives. Introduction of an electron-withdrawing maleimide group onto a [5]carbohelicene core contributes to the stabilized LUMO state in HeliIm as compared to that of [5]carbohelicene (Heli), whereas the energy level of HOMO state in MeO-HeliIm increases by introducing electron-donating methoxy (MeO) groups onto a HeliIm skeleton. The HOMO-LUMO gap of MeO-HeliIm is smaller than those of HeliIm and Heli, which is similar to the steady-state spectroscopic measurements. The absolute fluorescence quantum yield (Φ FL ) of HeliIm (0.37) largely increased as compared to [5]carbohelicene, Heli (0.04), whereas Φ FL of MeO-HeliIm (0.22) was slightly smaller than that of HeliIm. Theses photophysical processes including intersystem crossing are successfully explained by the kinetic discussions. Since [5]carbohelicene derivatives show the chirality, measurements of circular dichroism (CD) and circularly polarized luminescence (CPL) were successfully performed. In particular, HeliIm and MeO-HeliIm have provide excellent circularly polarized luminescence (CPL) and the values of the anisotropy factor g lum were estimated to be 2.4 × 10 −3 and 2.3 × 10 −3 , relatively. This is the first observation of CPL in [5]carbohelicene derivatives.

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Ethynyl thiophene-appended unsymmetrical zinc porphyrin sensitizers for dye-sensitized solar cells

Abstract: Zn porphyrin sensitizers with ethynyl thiophene linker, pyrene/fluorene donors and cyanoacrylic or malonic acid anchoring group were synthesized for DSSC applications. Conversion efficiency up to 3.14% was exhibited.

Cited by 21 publications

References 47 publications

Ultrafast Photoinduced Charge Separation Leading to High‐Energy Radical Ion‐Pairs in Directly Linked Corrole–C₆₀ and Triphenylamine–Corrole‐C₆₀ Donor–Acceptor Conjugates

Ultrafast Photoinduced Charge Separation Leading to High‐Energy Radical Ion‐Pairs in Directly Linked Corrole–C₆₀ and Triphenylamine–Corrole‐C₆₀ Donor–Acceptor Conjugates

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Synthetic Control of Photophysical Process and Circularly Polarized Luminescence of [5]Carbohelicene Derivatives Substituted by Maleimide Units

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Ethynyl thiophene-appended unsymmetrical zinc porphyrin sensitizers for dye-sensitized solar cells

Abstract: Zn porphyrin sensitizers with ethynyl thiophene linker, pyrene/fluorene donors and cyanoacrylic or malonic acid anchoring group were synthesized for DSSC applications. Conversion efficiency up to 3.14% was exhibited.

Cited by 21 publications

References 47 publications

Ultrafast Photoinduced Charge Separation Leading to High‐Energy Radical Ion‐Pairs in Directly Linked Corrole–C60 and Triphenylamine–Corrole‐C60 Donor–Acceptor Conjugates

Ultrafast Photoinduced Charge Separation Leading to High‐Energy Radical Ion‐Pairs in Directly Linked Corrole–C60 and Triphenylamine–Corrole‐C60 Donor–Acceptor Conjugates

Untitled

Synthetic Control of Photophysical Process and Circularly Polarized Luminescence of [5]Carbohelicene Derivatives Substituted by Maleimide Units

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Ultrafast Photoinduced Charge Separation Leading to High‐Energy Radical Ion‐Pairs in Directly Linked Corrole–C₆₀ and Triphenylamine–Corrole‐C₆₀ Donor–Acceptor Conjugates

Ultrafast Photoinduced Charge Separation Leading to High‐Energy Radical Ion‐Pairs in Directly Linked Corrole–C₆₀ and Triphenylamine–Corrole‐C₆₀ Donor–Acceptor Conjugates