Benzo[a]carbazole-Based Donor−π–Acceptor Type Organic Dyes for Highly Efficient Dye-Sensitized Solar Cells
journal contributionposted on 06.05.2015, 00:00 by Xing Qian, Yi-Zhou Zhu, Wen-Ying Chang, Jian Song, Bin Pan, Lin Lu, Huan-Huan Gao, Jian-Yu Zheng
A novel class of metal-free organic dyes based on benzo[a]carbazole have been designed, synthesized, and used in dye-sensitized solar cells for the first time. These types of dyes consisted of a cyanoacrylic acid moiety as the electron acceptor/anchoring group and different electron-rich spacers such as thiophene (JY21), furan (JY22), and oligothiophene (JY23) as the π-linkers. The photophysical, electrochemical, and photovoltaic properties, as well as theoretical calculations of these dyes were investigated. The photovoltaic performances of these dyes were found to be highly relevant to the π-conjugated linkers. In particular, dye JY23 exhibited a broad IPCE response with a photocurrent signal up to about 740 nm covering the most region of the UV–visible light. A DSSC based on JY23 showed the best photovoltaic performance with a Jsc of 14.8 mA cm–2, a Voc of 744 mV, and a FF of 0.68, achieving a power conversion efficiency of 7.54% under standard AM 1.5 G irradiation.