摘要： Four donor–conjugated spacer–acceptor (D–π–A) organic dyes containing cyclopentadithiophene unit as a part of the conjugated spacer are prepared and studied to investigate the effects of the conjugated spacer and donor on the short-circuit current and conversion efficiency of the corresponding DSSCs. Theoretical calculations reveal that a shorter conjugated spacer or a stronger donor leads to more effective electron injection upon photo excitation. Therefore, D–π–A typed dye with longer conjugated spacer may have higher absorption coefficient and longer λmax. Nevertheless, it may also have lower effective electron injection upon photo excitation. Calculation data also show that cyclopentadithiophene although is a good moiety for extending the conjugation length of the organic dyes, it also acts as an electron sink, decreasing the effective electron injection. The transition probability calculated with the electron density difference analyses combining with the experimental absorption and photovoltaic performance data provides a useful protocol for designing organic photosensitizers for DSSCs at the electronic and structural levels. A series of D–π–A dyes containing cyclopentadithiophene as a part of the conjugated spacer are prepared and their physicochemical properties and photovoltaic performance are tested. Combining the experimental and calculation data reveals that the efficiency of a DSC depends on the effective charge transfer (ECT) of the dye adsorbed on TiO2 upon excitation and ECT is significantly affected by the length of the conjugated spacer. [Display omitted] •Cyclopentadithiophene-containing D–π–A organic dyes for DSSC.•Theoretical calculation.•Donor and spacer depended electron injection efficiency of D–π–A organic dyes. 出版者： Elsevier Ltd 出版日期： 2013-12-01 出處： Dyes and pigments, 2013-12, Vol.99 (3), p.1091-1100 版權： 2013 Elsevier Ltd 識別號： ISSN: 0143-7208 識別號： EISSN: 1873-3743 識別號： DOI: 10.1016/j.dyepig.2013.08.016
