Speaker
Filippo De Angelis
(ISTM-CNR & Università di Perugia, Italy)
Description
Within today’s global challenge to capture and utilize solar energy for a sustainable development on a grand scale, dye sensitized solar cells (DSC), represent a particularly promising approach to the direct conversion of light into electrical energy at low cost and with high efficiency. In these devices, a dye sensitizer absorbs the solar radiation and transfers the photoexcited electron to a wide band-gap semiconductor electrode consisting of a mesoporous oxide layer composed of nanometer-sized particles, while the concomitant hole is transferred to the redox electrolyte or to a hole conductor. Ruthenium(II) complexes are widely employed as dye sensitizers, delivering record efficiencies in DSC. For further progress, however, higher conversion efficiencies need to be achieved. New sensitizers with tailored optical properties and a deeper understanding of the interaction between the dye and the TiO2 nanostructured electrode are essential.
As part of our continued research efforts in modeling the dye/semiconductor heterointerface, we investigated the reasons underlying the unmatched success and high photovoltaic efficiency of the prototypical Ruthenium(II) dyes. It was found that the DSSCs conversion efficiency markedly depended on detailed features of the sensitizer, such as the number of protons carried by the dye anchoring groups and the dye adsorption mode onto TiO2. Together with new design rules for dye sensitizers, our results open the way to the achievement of breakthrough DSSC efficiencies approaching 15%.
Author
Filippo De Angelis
(ISTM-CNR & Università di Perugia, Italy)
