Carbazole-dendrimer-based donor-π-acceptor type organic dyes for dye-sensitized solar cells: effect of the size of the carbazole dendritic donor.
Carbazole-dendrimer-based donor-π-acceptor type organic dyes for dye-sensitized solar cells: effect of the size of the carbazole dendritic donor.
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DOI：
10.1021/am500947k
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发表时间：
2014-05
影响因子：
9.5
通讯作者：
Pongsathorn Thongkasee;A-monrat Thangthong;Nittaya Janthasing;T. Sudyoadsuk;S. Namuangruk;Tinnagon Keawin;Siriporn Jungsuttiwong;V. Promarak
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文献类型：
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作者：
Pongsathorn Thongkasee;A-monrat Thangthong;Nittaya Janthasing;T. Sudyoadsuk;S. Namuangruk;Tinnagon Keawin;Siriporn Jungsuttiwong;V. Promarak
合成了一系列新型D-π-A型有机染料GnTA（n = 1-4），该染料以四代咔唑树枝状基元为供体，以联噻吩为π键，氰基丙烯酸为受体，并对其结构进行了表征.研究了新型染料作为染料增感剂的物理、热学、电化学和光电性能，并评价了咔唑树枝状给体对这些性能的影响。结果表明，增加染料分子的咔唑树枝状供体的大小或代增强了它们的总光吸收能力，不幸的是，由于它们的高分子体积，每单位TiO 2面积的染料吸收量减少。发现后者对DSSC的功率转换效率具有强烈的影响。重要的是，电化学阻抗谱（EIS）显示，供体的大小或代有一个显着的影响，在TiO 2/电解质界面的电子复合的电荷转移电阻，导致开路电压（Voc）的太阳能电池的差异。其中，含有第一代树枝化基元作为供体（具有最低分子体积）的染料G1 TA在模拟AM 1.5照射（100 mW cm（-2））下表现出最高的功率转换效率，为5.16%（Jsc = 9.89 mA cm（-2），Voc = 0.72 V，ff = 0.73）。
A series of novel D-π-A type organic dyes, namely, GnTA (n = 1-4), containing carbazole dendrons up to fourth generation as a donor, bithiophene as π-linkage, and cyanoacrylic acid as acceptor were synthesized and characterized for applications in dye-sensitized solar cells (DSSCs). The photophysical, thermal, electrochemical, and photovoltaic properties of the new dyes as dye sensitizers were investigated, and the effects of the carbazole dendritic donors on these properties were evaluated. Results demonstrated that increasing the size or generation of the carbazole dendritic donor of the dye molecules enhances their total light absorption abilities and unluckily reduces the amount of dye uptake per unit TiO2 area because of their high molecular volumes. The latter was found to have a strong effect on the power conversion efficiency of DSSCs. Importantly, electrochemical impedance spectroscopy (EIS) revealed that the size or generation of the donor had a significant influence on a charge-transfer resistance for electron recombination at the TiO2/electrolyte interface, causing a difference in open circuit voltage (Voc) of the solar cells. Among them, dye G1TA containing first generation dendron as a donor (having lowest molecular volume) exhibited the highest power conversion efficiency of 5.16% (Jsc = 9.89 mA cm(-2), Voc = 0.72 V, ff = 0.73) under simulated AM 1.5 irradiation (100 mW cm(-2)).