D鈭捪€鈥揂 Porphyrin Sensitizers with 蟺-Extended Conjugation for Mesoscopic Solar Cells

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• 作者：Jianfeng Lu ; Bingyan Zhang ; Huailiang Yuan ; Xiaobao Xu ; Kun Cao ; Jin Cui ; Shuangshuang Liu ; Yan Shen ; Yibing Cheng ; Jie Xu ; Mingkui Wang
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：July 10, 2014
• 年：2014
• 卷：118
• 期：27
• 页码：14739-14748
• 全文大小：530K
• ISSN：1932-7455

文摘

Two new D鈭捪€鈥揂 porphyrin sensitizers (coded as LW5 and LW6) with extended conjugation units at 蟺 moiety are designed and synthesized for mesoscopic solar cells. While keeping the same donor moiety to the well-investigated porphyrin LD14, introduction of various linker units in the two new sensitizers with electron rich property can red-shift the absorption spectra to 710 nm, such as thiophene for the LW5 dye between porphyrin macrocycle and 4-ethynylbenzoic acid (i.e., the acceptor). The excited singlet state lifetime and charge regeneration rate constants have been examined to be 140 ps and 1 脳 10^鈥? cm s^鈥? with time-resolved photoluminescence and scanning electrochemical microscopy measurements, respectively, indicating fast electron injection from the excited dyes to the TiO₂ conduction band followed by quick charge regeneration of dye cations by electrolytes containing a [Co(bpy)₃]^2+/3+ redox couple. LW5 and LW6 dyes have been evaluated in dye-sensitized solar cells, showing efficiencies of 7.8% and 6.1% with [Co(bpy)₃]^2+/3+ based electrolytes (measured under standard test conditions), respectively. A detailed investigation with transient photovoltage decay measurement provides important information on factors affecting the principal photovoltaic parameters.