Exciton-Sensitized Nanostructured Solar Cells (XNSC)

  • Eva Unger, Center of Molecular Devices, Ångström laboratory, Dept. of Physical and Analytical Chemistry, 75120 Uppsala, Sweden, Sweden
  • Dr Gerrit Boschloo, Center of Molecular Devices, The Royal Institute of Technology, 10044 Stockholm, Sweden, Sweden
  • Prof Anders Hagfeldt, Center of Molecular Devices, Ångström laboratory, Dept. of Physical and Analytical Chemistry, 75120 Uppsala, Sweden, Sweden
  • Dr Philippe Leriche, Group Linear Conjugated Systems, CIMMA-CNRS, University of Angers, France, France
  • Dr Antonio Cravino, Group Linear Conjugated Systems, CIMMA-CNRS, University of Angers, France, France
  • Dr Jean Roncali, Group Linear Conjugated Systems, CIMMA-CNRS, University of Angers, France, France

    • A new type of solar cell is presented that combines features of dye sensitized nanostructured solar cells and organic bulk heterojunction cells. A dye-sensitized inorganic metal oxide like TiO or ZnO serves as n-type contact while the liquid electrolyte is replaced with a p-type organic hole conducting dye. A metal film evaporated directly onto the organic dye serves as counter electrode.
    Excitons created in this “bulk” dye diffuse to the dye attached at the surface of the metal oxide where the excitation energy is trapped. After injection of an electron into the conduction band of the metal oxide the remaining hole on the injection dye is transferred to the hole conducting bulk dye layer.
    Currently, suitable materials for bulk and injection dyes are investigated. Organic dyes with a triaryl moiety are expected to have good hole conducting properties. The injection dye has to be energetically matched to the bulk dye in order to collect excitons and it has to be equipped with a suitable anchoring group to the inorganic semiconductor to promote fast electron injection. The presence of an injection dye layer should improve the interpenetration between the organic and inorganic materials.
    We will present preliminary results on the transport of charge carriers in the dye and metal oxide phases and the recombination of charge carriers at the interface in these new devices. The regeneration of the oxidized dye by the hole-conductor and the interpenetration of the materials will be investigated by photoinduced absorption spectroscopy (PIA).
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