Organic Dyes Containing Fluorene Decorated with Imidazole Units for Dye-Sensitized Solar Cells

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• 作者：Dhirendra Kumar ; K. R. Justin Thomas ; Chuan-Pei Lee ; Kuo-Chuan Ho
• 刊名：Journal of Organic Chemistry
• 出版年：2014
• 出版时间：April 4, 2014
• 年：2014
• 卷：79
• 期：7
• 页码：3159-3172
• 全文大小：817K
• 年卷期：v.79,no.7(April 4, 2014)
• ISSN：1520-6904

文摘

New organic dyes containing fluorene functionalized with two imidazole chromophores as donors and cyanoacrylic acid acceptors have been synthesized and successfully demonstrated as sensitizers in nanocrystalline TiO₂-based dye-sensitized solar cells (DSSCs). The monoimidazole analogues were also synthesized for comparison. The Sommelet reaction of bromomethylated 2-bromo-9,9-diethyl-9H-fluorene produced the key precursor 7-bromo-9,9-diethyl-9H-fluorene-2,4-dicarbaldehyde required for the preparation of imidazole-functionalized fluorenes. Since the dyes possess weak donor segment, the electron-richness of the conjugation pathway dictated the optical, electrochemical, and photovoltaic properties of the dyes. The dyes served as sensitizers in DSSC and exhibited moderate efficiency up to 3.44%. The additional imidazole present on the fluorene has been found to retard the electron recombination due to the bulkier hydrophobic environment and led to high open-circuit voltage in the devices.