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ABSTRACT: The design, synthesis and characterization of five diphenylhydrazone end capped molecules as donors for Bulk Heterojunction (BHJ) solar cells are described. The use of the hydrazone donor instead of the more common amine one is advantageous in terms of synthetic access and overall stability. We show that the variation of both the nature and the substitution pattern of the electron deficient conjugated bridge enables the tuning of the optical energy gap as well as of the HOMO and LUMO. In particular, our data show that the low energy shift of the HOMO level along the series of hydrazone compounds, one of the critical parameters affecting the performance of BHJ cells, is as high as 0.42 eV. We tested all derivatives as donors in a BHJ configuration, using the fullerene derivative [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the acceptor. We found that the trend we observed in the progressive stabilization of the chromophore HOMO level upon increasing the electron accepting capabilities of the conjugated bridge is reflected in the progressive increase of the cell open circuit voltage (Voc). Our preliminary results show that it is possible to obtain a Voc as high as 0.74 V, along with a power conversion efficiency of 1.2%.
Journal of Materials Chemistry 01/2013; 1(7):2631-2638. · 5.97 Impact Factor
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ABSTRACT: We show the design and synthesis of new perfluorinated nitrosopyrazolone-based ligands and the original method employed for their complexation of erbium ions in the presence of the co-ligand perfluorotriphenylphosphine oxide; the resulting chelate is non-hygroscopic, solution processable and possesses a NIR emission with lifetimes as long as 16 micros.
Chemical Communications 09/2009; · 6.17 Impact Factor
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Luca Beverina, Maurizio Crippa,
Patrizio Salice,
Riccardo Ruffo,
Camilla Ferrante,
Ilaria Fortunati,
Raffaella Signorini,
Claudio Maria Mari,
Renato Bozio,
Antonio Facchetti,
Giorgio A. Pagani
Chemistry of Materials. 05/2008; 20(10):3242-3244.
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Luca Beverina, Maurizio Crippa,
Mirko Landenna,
Riccardo Ruffo,
Patrizio Salice,
Fabio Silvestri,
Silvia Versari,
Alessandro Villa,
Luca Ciaffoni,
Elisabetta Collini,
Camilla Ferrante,
Silvia Bradamante,
Claudio M Mari,
Renato Bozio,
Giorgio A Pagani
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ABSTRACT: Singlet oxygen sensitization by organic molecules is a topic of major interest in the development of both efficient photodynamic therapy (PDT) and aerobic oxidations under complete green chemistry conditions. We report on the design, synthesis, biology, and complete spectroscopic characterization (vis-NIR linear and two-photon absorption spectroscopy, singlet oxygen generation efficiencies for both one- and two-photon excitation, electrochemistry, intrinsic dark toxicity, cellular uptake, and subcellular localization) of three classes of innovative singlet oxygen sensitizers pertaining to the family of symmetric squaraine derivatives originating from pi-excessive heterocycles. The main advantage of pi-extended squaraine photosensitizers over the large number of other known photosensitizers is their exceedingly strong two-photon absorption enabling, together with sizable singlet oxygen sensitization capabilities, for their use at the clinical application relevant wavelength of 806 nm. We finally show encouraging results about the dark toxicity and cellular uptake capabilities of water-soluble squaraine photosensitizers, opening the way for clinical small animal PDT trials.
Journal of the American Chemical Society 03/2008; 130(6):1894-902. · 9.91 Impact Factor
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Luca Beverina, Maurizio Crippa,
Mirko Landenna,
Riccardo Ruffo,
Patrizio Salice,
Fabio Silvestri,
Silvia Versari,
Alessandro Villa,
Luca Ciaffoni,
Elisabetta Collini,
Camilla Ferrante,
Silvia Bradamante,
Claudio M. Mari,
Renato Bozio,
Giorgio A. Pagani
[show abstract]
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ABSTRACT: Singlet oxygen sensitization by organic molecules is a topic of major interest in the development of both efficient photodynamic therapy (PDT) and aerobic oxidations under complete green chemistry conditions. We report on the design, synthesis, biology, and complete spectroscopic characterization (vis−NIR linear and two-photon absorption spectroscopy, singlet oxygen generation efficiencies for both one- and two-photon excitation, electrochemistry, intrinsic dark toxicity, cellular uptake, and subcellular localization) of three classes of innovative singlet oxygen sensitizers pertaining to the family of symmetric squaraine derivatives originating from π-excessive heterocycles. The main advantage of π-extended squaraine photosensitizers over the large number of other known photosensitizers is their exceedingly strong two-photon absorption enabling, together with sizable singlet oxygen sensitization capabilities, for their use at the clinical application relevant wavelength of 806 nm. We finally show encouraging results about the dark toxicity and cellular uptake capabilities of water-soluble squaraine photosensitizers, opening the way for clinical small animal PDT trials.
01/2008;
