文献类型：期刊文献

英文题名：Rational Molecular Engineering of Indoline-Based D-A-π-A Organic Sensitizers for Long-Wavelength-Responsive Dye-Sensitized Solar Cells

作者：Zhang, Weiwei[1]; Wu, Yongzhen[1]; Zhu, Haibo[1]; Chai, Qipeng[1]; Liu, Jingchuan[1]; Li, Hui[1]; Song, Xiongrong[1]; Zhu, Wei-Hong[1]

机构：[1] Shanghai Key Laboratory of Functional Materials Chemistry, Key Laboratory for Advanced Materials, Institute of Fine Chemicals, Collaborative Innovation Center for Coal Based Energy [I-CCE], East China University of Science and Technology, Shanghai, 200237, China

年份：2015

卷号：7

期号：48

起止页码：26802

外文期刊名：ACS Applied Materials and Interfaces

收录：EI(收录号：20155101683118)

语种：英文

外文关键词：Solar power generation - Cell engineering - Charge transfer - Display devices - Dyes - Electrolytes

摘要：Indoline-based D-A-π-A organic sensitizers are promising candidates for highly efficient and long-term stable dye-sensitized solar cells (DSSCs). In order to further broaden the spectral response of the known indoline dye WS-2, we rationally engineer the molecular structure through enhancing the electron donor and extending the π-bridge, resulting in two novel indoline-based D-A-π-A organic sensitizers WS-92 and WS-95. By replacing the 4-methylphenyl group on the indoline donor of WS-2 with a more electron-rich carbazole unit, the intramolecular charge transfer (ICT) absorption band of dye WS-92 is slightly red-shifted from 550 nm (WS-2) to 554 nm (WS-92). In comparison, the incorporation of a larger π-bridge of cyclopentadithiophene (CPDT) unit in dye WS-95 not only greatly bathochromatically tunes the absorption band to 574 nm but also largely enhances the molar extinction coefficients (Ε), thus dramatically improving the light-harvesting capability. Under the standard global AM 1.5 solar light condition, the photovoltaic performances of both organic dyes have been evaluated in DSSCs on the basis of the iodide/triiodide electrolyte without any coadsorbent or cosensitizer. The DSSCs based on WS-95 display better device performance with power conversion efficiency (η) of 7.69%. The additional coadsorbent in the dye bath of WS-95 does not improve the photovoltaic performance, indicative of its negligible dye aggregation, which can be rationalized by the grafted dioctyl chains on the CPDT unit. The cosensitization of WS-95 with a short absorption wavelength dye S2 enhances the IPCE and improves the η to 9.18%. Our results indicate that extending the π-spacer is more rational than enhancing the electron donor in terms of broadening the spectral response of indoline-based D-A-π-A organic sensitizers. ? 2015 American Chemical Society.