Efficient Electron Transfer and Sensitizer Regeneration in Stable π-Extended Tetrathiafulvalene-Sensitized Solar Cells

Sophie Wenger , Pierre-Antoine Bouit (1) , Qianli Chen , Joël Teuscher , Davide Di Censo , Robin Humphry-Baker , Jaques-E. Moser , Juan Luis Delgado , Nazario Martín , Shaik M. Zakeeruddin , Michael Grätzel

1 ISCR - Institut des Sciences Chimiques de Rennes

The development of metal-free organic sensitizers is a key issue in dye-sensitized solar cell research. We report successful photovoltaic conversion with a new class of stable tetrathiafulvalene derivatives, showing surprising electrochemical and kinetic properties. With time-resolved spectroscopy we could observe highly efficient regeneration of the photo-oxidized tetrathiafulvalene sensitizers, which were attached to a mesoporous TiO2 film, by a redox mediator in the pores (iodide/tri-iodide), even though the measured driving force for regeneration was only about 150 mV. This important proof-of-concept shows that sensitizers with a small driving force, i.e. the oxidation potential is separated from the redox potenial of mediator by as little as 150 mV, can operate functionally in dye-sensitized solar cells and eventually aid to reduce photovoltage losses due to poor energetic alignment of the materials

Domains: Chemical Sciences; Organic chemistry

Sophie Wenger, Pierre-Antoine Bouit, Qianli Chen, Joël Teuscher, Davide Di Censo, et al.. Efficient Electron Transfer and Sensitizer Regeneration in Stable π-Extended Tetrathiafulvalene-Sensitized Solar Cells. Journal of the American Chemical Society, 2010, 132 (14), pp.5164-5169. ⟨10.1021/ja909291h⟩. ⟨hal-01089797⟩