π–π and p–π conjugation, which is more efficient for intermolecular charge transfer in starburst triarylamine donors of platinum acetylide sensitizers?
摘要:
Two novel starburst donors based platinum acetylide sensitizers with pi-pi conjugated span group (2-vinylthiophene) were synthesized and applied in dye-sensitized solar cells (DSSCs). The photovoltaic performances of sensitizers were investigated by photophysical, photovoltaic, electrochemical, and a theoretical approach. Compared with similar triphenylamine based platinum acetylide sensitizers which do not contain a 2-vinylthiophene group, it was found that the introduction of 2-vinylthiophene as a span group increased the donating ability of donor and the coplanar property between the donor and pi-bridge, which are in favour of the intramolecular charge transfer. Moreover, the new DSSCs based sensitizers displayed a power conversion efficiency of 2.80% and 2.95%, which is significantly improved over that determined for the non-vinylthiophene containing analogues. (C) 2014 Elsevier Ltd. All rights reserved.