Structure–Performance Correlations of Organic Dyes with an Electron‐Deficient Diphenylquinoxaline Moiety for Dye‐Sensitized Solar Cells |
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| Authors: | Dr Sie‐Rong Li Dr Chuan‐Pei Lee Po‐Fan Yang Chia‐Wei Liao Mandy M Lee Dr Wei‐Lin Su Chun‐Ting Li Prof?Dr Hao‐Wu Lin Prof?Dr Kuo‐Chuan Ho Dr Shih‐Sheng Sun |
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| Affiliation: | 1. Institute of Chemistry, Academia Sinica, 11529 Taipei, Taiwan (ROC);2. Department of Chemical Engineering, National Taiwan University, 11529 Taipei, Taiwan (ROC);3. Department of Materials Science and Engineering, National Tsing Hua University, 30013 Hsinchu, Taiwan (ROC) |
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| Abstract: | The high performances of dye‐sensitized solar cells (DSSCs) based on seven new dyes are disclosed. Herein, the synthesis and electrochemical and photophysical properties of a series of intentionally designed dipolar organic dyes and their application in DSSCs are reported. The molecular structures of the seven organic dyes are composed of a triphenylamine group as an electron donor, a cyanoacrylic acid as an electron acceptor, and an electron‐deficient diphenylquinoxaline moiety integrated in the π‐conjugated spacer between the electron donor and acceptor moieties. The DSSCs based on the dye DJ104 gave the best overall cell performance of 8.06 %; the efficiency of the DSSC based on the standard N719 dye under the same experimental conditions was 8.82 %. The spectral coverage of incident photon‐to‐electron conversion efficiencies extends to the onset at the near‐infrared region due to strong internal charge‐transfer transition as well as the effect of electron‐deficient diphenylquinoxaline to lower the energy gap in these organic dyes. A combined tetraphenyl segment as a hydrophobic barrier in these organic dyes effectively slows down the charge recombination from TiO2 to the electrolyte and boosts the photovoltage, comparable to their RuII counterparts. Detailed spectroscopic studies have revealed the dye structure–cell performance correlations, to allow future design of efficient light‐harvesting organic dyes. |
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| Keywords: | donor– acceptor systems dyes/pigments energy conversion sensitizers solar cells |
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