文献类型：期刊文献

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

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

机构：[1]E China Univ Sci & Technol, Shanghai Key Lab Funct Mat Chem, Key Lab Adv Mat, Shanghai 200237, Peoples R China; E China Univ Sci & Technol, Inst Fine Chem, Collaborat Innovat Ctr Coal Based Energy I CCE, Shanghai 200237, Peoples R China

年份：2015

卷号：7

期号：48

起止页码：26802

外文期刊名：ACS APPLIED MATERIALS & INTERFACES

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000366339100057)】；

基金：This work was supported by NSFC for Creative Research Groups (21421004) and Distinguished Young Scholars (21325625), NSFC/China, the Oriental Scholarship, Science and Technology Commission of Shanghai Municipality (15XD1501400), and the Fundamental Research Funds for the Central Universities (WJ1416005).

语种：英文

外文关键词：indoline dyes; solar cells; light harvesting; co-sensitization; photovoltaics

摘要：Indoline-based D-A-g-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 sr-bridge, resulting in two novel indoline-based D-A-pi-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 sr-bridge of cydopentadithiophene (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 (epsilon), 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 (eta) 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 eta to 9.18%. Our results indicate that extending the pi-spacer is more rational than enhancing the electron donor in terms of broadening the spectral response of indoline-based D-A-pi-A organic sensitizers.