Triphenylamine-based starburst dyes with carbazole and phenothiazine antennas for dye-sensitized solar cells

• Published in: Journal of power sources 2012-02, Vol.199, p.426-431
• Main Authors: Wan, ZhongQuan, Jia, ChunYang, Zhang, JiaQiang, Duan, YanDong, Lin, Yuan, Shi, Yu
• Format: Article
• Language: English
• Subjects: Applied sciences; Carbazole; Conversion; Density; Dye-sensitized solar cells; Dyes; Energy; Exact sciences and technology; Natural energy; Phenothiazine; Phenothiazines; Photovoltaic cells; Photovoltaic conversion; Rhodanine-3-acetic acid; Solar cells; Solar cells. Photoelectrochemical cells; Solar energy; Starburst; Titanium dioxide; Triphenylamine; Volatile organic compounds
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2011.10.062

[Display omitted] ► The phenothiazine group as secondary electron donor was introduced into organic dyes. ► The dyes with the starburst conformations can reduce aggregation between molecules and avoid the charge recombination processes of injected electrons with triiodide in the electrolyte. ► Power conversion efficiency of 3.1% was obtained for the DSSCs based on WD-2 without deoxycholic acid. Two new triphenylamine-based starburst dyes ( WD-2 and WD-3) are designed, in which the carbazole/phenothiazine groups are used as secondary electron donor and the rhodanine-3-acetic acid moiety as the acceptor. We report the synthesis, photophysical and electrochemical properties of the dyes as well as their applications in dye-sensitized solar cells (DSSCs). Under standard global AM 1.5 solar condition, the WD-2 sensitized cell gives a short circuit photocurrent density J sc = 6.4 mA cm −2, an open circuit voltage V oc = 600 mV, a fill factor ff = 0.8, corresponding to an overall conversion efficiency of 3.1%. Under the same conditions, the WD-3 sensitized cell gives J sc = 4.7 mA cm −2, V oc = 570 mV, and ff = 0.78, corresponding to an overall conversion efficiency of 2.1%. The conversion efficiency is increased about 47% from WD-2 sensitized cell to WD-3 sensitized cell. The research results show that the inefficient electron injection from the excited dyes into the conduction band of TiO 2 results in the low efficiencies of DSSCs based on the two dyes.