(Invited) Push-Pull p�-Extended porphyrins for Solar Energy Conversion

Dye-sensitized solar-cells (DSSCs) have emerged as one of the most promising photovoltaic technologies in solar energy conversion.^1-3 Despite of the advances in the last two decades, organic dyes having better overlap with the solar spectrum and high thermostability are still in high demands. p-Extended porphyrins appear to be ideal candidates to satisfy these criteria as sensitizer for DSSCs. In this work, a novel class of push-pull p-extended porphyrins was prepared. To our knowledge, the porphyrins presented here represent the first examples of pull-pull p-extended porphyrins. The push-pull functional groups installed at the extended porphyrin periphery are expected to facilitate intramolecular and intermolecular electron transfer. Red-shifted and broadened absorptions are also expected due to the push-pull groups along with the p-extension. The design and synthesis of these organic materials take advantage of the chemistry of bromoporphyrins^4,5 and a palladium (0) catalyzed cascade reaction developed in the Wang group.^6-8 The electronic and optical properties of these p-extended porphyrins were measured using UV-Vis spectroscopy, life-time and steady state fluorescence spectroscopy, and cyclic voltammetry. DFT calculations were also performed for these porphyrins. The solar to electricity conversion efficiency of these porphyrins in DSSC were evaluated.

Reference

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