Person:
López Duarte, Ismael

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First Name
Ismael
Last Name
López Duarte
URI
https://hdl.handle.net/20.500.14352/86447
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Farmacia
Department
Química en Ciencias Farmacéuticas
Area
Química Física
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2008 - 20092
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    Catalysis of Recombination and Its Limitation on Open Circuit Voltage for Dye Sensitized Photovoltaic Cells Using Phthalocyanine Dyes
    (Journal of the American Chemical Society, 2008) O'Regan, Brian C.; López Duarte, Ismael; Martínez Díaz, María Victoria; Forneli Rubio, María Ámparo; Albero Sancho, Josep; Morandeira Ramírez, Ana; Palomares Gil, Emilio; Torres Cebada, Tomás; Durrant, James Robert
    In order to increase the energy efficiency of dye-sensitized solar cells beyond 10%, an improved dye needs to be developed with greater light absorption in the red and near-infrared. Many dyes have been tested for this purpose; however, no dye with significant absorption beyond 750 nm has functioned properly. We have examined a series of ruthenium phthalocyanines, a dye class with large and tunable absorption in the red. For these dyes we observe a large reduction in the output voltage of the cells relative to the benchmark dye (N719). By examination of photovoltage transients and charge density measurements, we demonstrate that this reduction in voltage is caused by a 100-fold increase in the rate constant for recombination (iodine reduction) at the TiO2/electrolyte interface. N719, however, does not seem to catalyze this reaction. By examination of the literature, we propose that catalysis of the recombination reaction may be occurring for many other classes of potentially useful dyes including porphyrins, coumarins, perylenes, cyanines, merocyanines, and azulene. This widespread ability of the dye to catalyze recombination has not been appreciated before. This finding has important implications for future work to improve the red response of dye sensitized photovoltaics.
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    A squaraine–phthalocyanine ensemble: towards molecular panchromatic sensitizers in solar cells
    (Chemical Communications, 2009) Silvestri, Fabio; López Duarte, Ismael; Seitz, Wolfgang; Beverina, Luca; Martínez Díaz, María Victoria; Marks, Tobin J.; Guldi, Dirk M.; Pagani, Giorgio A.; Torres Cebada, Tomás
    A supramolecular phthalocyanine–squaraine ensemble which exhibits a large coverage of the solar spectrum from 850 to 250 nm has been prepared and characterized both photophysically and in bulk heterojunction solar cells.