@article{Yella:201030, title = {Molecular Engineering of Push-Pull Porphyrin Dyes for Highly Efficient Dye-Sensitized Solar Cells: The Role of Benzene Spacers}, author = {Yella, Aswani and Mai, Chi-Lun and Zakeeruddin, Shaik M. and Chang, Shu-Nung and Hsieh, Chi-Hung and Yeh, Chen-Yu and Graetzel, Michael}, publisher = {Wiley-Blackwell}, journal = {Angewandte Chemie-International Edition}, address = {Weinheim}, number = {11}, volume = {53}, pages = {5. 2973-2977}, year = {2014}, abstract = {Porphyrins have drawn much attention as sensitizers owing to the large absorption coefficients of their Soret and Q bands in the visible region. In a donor and acceptor zinc porphyrin we applied a new strategy of introducing 2,1,3-benzothiadiazole (BTD) as a pi-conjugated linker between the anchoring group and the porphyrin chromophore to broaden the absorption spectra to fill the valley between the Soret and Q bands. With this novel approach, we observed 12.75% power-conversion efficiency under simulated one-sun illumination (AM1.5G, 100 mW cm(-2)). In this study, we showed the importance of introducing the phenyl group as a spacer between the BTD and the zinc porphyrin in achieving high power-conversion efficiencies. Time-resolved fluorescence, transient-photocurrent-decay, and transient-photovoltage-decay measurements were employed to determine the electron-injection dynamics and the lifetime of the photogenerated charge carriers.}, url = {http://infoscience.epfl.ch/record/201030}, doi = {10.1002/anie.201309343}, }