Porphyrins as light harvesters in the dye-sensitised TiO2 solar cell

Campbell, Wayne M.; Burrell, Anthony K.; Officer, David L.; Jolley, K. W.

doi:10.1016/j.ccr.2004.01.007

Cited by 754 publications

(532 citation statements)

References 43 publications

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“…13 However, TiO 2 lms prepared for solar cell purposes are usually thick and very dispersive, and thus inappropriate for gas sensing when using UV-visible spectroscopy. Microstructured TiO 2 lms prepared by glancing angle physical vapor deposition (GAPVD) provide the perfect substrate for these composite lms, given their transparency, high porosity, low refractive index and controlled thickness.…”

Section: Introductionmentioning

confidence: 99%

Anchoring effect on (tetra)carboxyphenyl porphyrin/TiO₂composite films for VOC optical detection

et al. 2014

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The optical gas sensing properties of Zn-(II) -5,10,15,20-tetra(3-carboxyphenyl)porphyrin (m-ZnTCPP) and Zn-(II)-5,10,15,20-tetra(4-carboxyphenyl)porphyrin (p-ZnTCPP) bound to microcolumnar TiO 2 thin films have been compared and explained in terms of their different molecular structure and anchoring to the titania surface. This different binding has been confirmed by specular reflectance FTIR revealing that m-ZnTCPP is bound by its four carboxylic groups in contrast to p-ZnTCPP where two or three of these groups remain unanchored. As a consequence, the Soret band of the para derivative is blue shifted with respect to the solution, indicating H aggregation, while m-ZnTCPP remained in its monomeric form due to the planar anchoring by the four COOH groups to the titania matrix that would avoid porphyrin aggregation. The sensing performance of the two systems has been assessed by analyzing the spectral changes in their UV-visible spectra under exposure to six volatile organic compounds. Although the highly porous and non-dispersive TiO 2 matrix allow good sensing ability in both cases, the response of the m-ZnTCPP/TiO 2 composite has been found to be more intense and faster than that of p-ZnTCPP.Moreover, the use of identification patterns also indicates that the meta derivative achieves a more selective recognition of the selected analytes. This improvement in the sensing capabilities of m-ZnTCPP has been attributed to the absence of aggregation between adjacent macrocycles.

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Section: Introductionmentioning

confidence: 99%

Anchoring effect on (tetra)carboxyphenyl porphyrin/TiO₂composite films for VOC optical detection

et al. 2014

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“…[5][6][7][8] The efficient light harvesting potential of porphyrins, exemplified by their primary role in photosynthesis, makes them promising candidates for photosensitizers within DSSCs. 7,9 Their synthesis is relatively straightforward, and their optical and electronic properties can be easily tuned via chemical modification of the porphyrin core, 10 the number of porphyrin units, 11,12 and the linker between the core and the inorganic oxide. 13 The capability of porphyrin sensitizers was recently highlighted by a report demonstrating a new DSSC benchmark efficiency of 12.3 % under AM 1.5 full sunlight for a device with a donor-π-acceptor zinc porphyrin sensitizer coupled with a cobalt-based redox mediator.…”

Section: Introductionmentioning

confidence: 99%

Cation Exchange at Semiconducting Oxide Surfaces: Origin of Light-Induced Performance Increases in Porphyrin Dye-Sensitized Solar Cells

et al. 2013

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The origin of simultaneous improvements in the short-circuit current density ( Jsc) and open-circuit voltage (Voc) of porphyrin dye-sensitized TiO2 solar cells following white light illumination was studied by systematic variation of several different device parameters. Reduction of the dye surface loading resulted in greater relative performance enhancements, suggesting open space at the TiO2 surface expedites the process. Variation of the electrolyte composition and subsequent analysis of the conduction band potential shifts suggested that a light-induced replacement of surface-adsorbed lithium (Li+) ions with dimethylpropylimidazolium (DMPIm+) ions was responsible for an increased electron lifetime by decreasing the recombination with the redox mediator. Variation of the solvent viscosity was found to affect the illumination time required to generate increased performance, while similar performance enhancements were not replicated by application of negative bias under dark conditions, indicating the light exposure effect was initiated by formation of dye cation molecules following photoexcitation. The substituents and linker group on the porphyrin chromophore were both varied, with light exposure producing increased electron lifetime and Voc for all dyes; however, increased Jsc values were only measured for dyes containing binding moieties with multiple carboxylic acids. It was proposed that the initial injection limitation and/or fast recombination process in these dyes arises from the presence of lithium at the surface, and the improved injection and/or retardation of fast recombination after light exposure is caused by the Li+ removal by cation exchange under illumination. there an initial injection limitation and/or fast recombination process in these dyes arises from the presence of lithium at the surface, and the improved injection and/or retardation of fast recombination after light exposure was caused by the Li + removal by cation exchange under illumination.

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“…[1][2][3][4][5][6][7][8][9][10][11][12] A great number of dyes have been tested as sensitizers during the past 15 years in pursuit of high efficiency (η). Accordingly, the η has reached ∼11% in the laboratory scale.…”

Section: Introductionmentioning

confidence: 99%

A Strategy To Increase the Efficiency of the Dye-Sensitized TiO₂ Solar Cells Operated by Photoexcitation of Dye-to-TiO₂ Charge-Transfer Bands

et al. 2005

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Dye-sensitized nanoporous TiO 2 solar cells (DSSCs) can be classified into two types, namely, Type-I and Type-II. Type-I DSSCs are the DSSCs in which electrons are injected from the adsorbed dyes by photoexcitation of the dyes followed by electron injection from the excited dyes to TiO 2 (pathway A). Type-II DSSCs are the DSSCs in which electrons are injected not only by pathway A but also by direct one-step electron injection from the dyes to TiO 2 by photoexcitation of the dye-to-TiO 2 charge-transfer (DTCT) bands (pathway B). The DSSCs employing catechol (Cat) or its derivatives as the sensitizers have been the typical examples of Type-II DSSCs. However, their solar energy-to-electricity conversion efficiencies (η) have never exceeded 0.7%, and the external quantum efficiencies (EQE) at the absorption maximums of the DTCT bands have never exceeded 10%. We found that the attachment of electron-donating compounds such as (pyridin-4-yl)vinyl and (quinolin-4-yl)vinyl, respectively, to Cat (designated as Cat-v-P and Cat-v-Q, respectively) leads to 2-and 2.7-fold increases, respectively, in η, driven by large increases in short circuit current (J sc ). The EQE increased from 8.5 to 30% at 400 nm upon changing from Cat to Cat-v-P, at which only the DTCT band absorbs. In the case of the Cat-v-Q-sensitized DSSC, even the η obtained by exciting only the DTCT band was higher than 1%. Interestingly, the illumination of only the DTCT band resulted in the increase of fill factor from 62.6% to 72.3%. This paper provides for the first time an insight into the strategy to increase the η values of Type-II DSSCs.

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Porphyrins as light harvesters in the dye-sensitised TiO2 solar cell

Cited by 754 publications

References 43 publications

Anchoring effect on (tetra)carboxyphenyl porphyrin/TiO₂composite films for VOC optical detection

Anchoring effect on (tetra)carboxyphenyl porphyrin/TiO₂composite films for VOC optical detection

Cation Exchange at Semiconducting Oxide Surfaces: Origin of Light-Induced Performance Increases in Porphyrin Dye-Sensitized Solar Cells

A Strategy To Increase the Efficiency of the Dye-Sensitized TiO₂ Solar Cells Operated by Photoexcitation of Dye-to-TiO₂ Charge-Transfer Bands

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Porphyrins as light harvesters in the dye-sensitised TiO2 solar cell

Cited by 754 publications

References 43 publications

Anchoring effect on (tetra)carboxyphenyl porphyrin/TiO2composite films for VOC optical detection

Anchoring effect on (tetra)carboxyphenyl porphyrin/TiO2composite films for VOC optical detection

Cation Exchange at Semiconducting Oxide Surfaces: Origin of Light-Induced Performance Increases in Porphyrin Dye-Sensitized Solar Cells

A Strategy To Increase the Efficiency of the Dye-Sensitized TiO2 Solar Cells Operated by Photoexcitation of Dye-to-TiO2 Charge-Transfer Bands

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Anchoring effect on (tetra)carboxyphenyl porphyrin/TiO₂composite films for VOC optical detection

Anchoring effect on (tetra)carboxyphenyl porphyrin/TiO₂composite films for VOC optical detection

A Strategy To Increase the Efficiency of the Dye-Sensitized TiO₂ Solar Cells Operated by Photoexcitation of Dye-to-TiO₂ Charge-Transfer Bands