Novel π-extended porphyrin derivatives for use in dye-sensitized solar cells
摘要:
成功合成了两种新型供体-π-受体(D-π-A 型)卟啉染料,并将其用于染料敏化太阳能电池(DSSC)。这两种卟啉的分子结构都是由相同的二烷基取代二苯基氨基单元作为供体部分,并在 5,15-meso 位置上有两个双烷氧基苯基取代基。受体部分由不同的乙炔连接π-延伸桥和作为锚定基团的氰基丙烯酸(染料 I)或羧基苯基(染料 II)组成。为了研究在卟啉和受体单元之间加入π-延伸桥的效果,我们采用了两种不同的π-延伸桥,如 2,2′-噻吩和 2-(苯乙炔基)-噻吩。其中,染料 II 在供体取代的卟啉和羧酸基团之间含有两个三键。这些修饰可能会减少染料在 TiO 2 表面的聚集。在所有测得的偏置电位范围内,含有染料 II 的电池的电荷重组电阻和扩散长度都相对较高,这意味着当染料 II 分子吸附在 TiO 2 表面时,注入电子的电子重组损耗被高度抑制。最终,在 AM 1.5 照明(100 mW.cm-2)条件下,在 0.46 cm2 的光活性区域内,含有 2,2′-噻吩 π-间隔物并通过羧基苯基锚定的染料 II 比通过氰基丙烯酸基锚定 2-(苯乙炔基)噻吩(PCE = 3.5%)的染料 I 显示出更高的功率转换效率,达到 6.7%。
We designed highlyefficient porphyrin sensitizers with two phenyl groups at meso-positions of the macrocycle bearing two ortho-substituted long alkoxyl chains for dye-sensitizedsolarcells; the ortho-substituted devices exhibit significantly enhanced photovoltaic performances with the best porphyrin, LD14, showing J(SC) = 19.167 mA cm(-2), V(OC) = 0.736 V, FF = 0.711, and overall power conversion
我们设计了一种高效的卟啉敏化剂,在大环的中间位置带有两个苯基,带有两个邻位取代的长烷氧基长链,用于染料敏化太阳能电池;邻位取代的器件具有最佳的卟啉LD14,光伏性能显着提高,显示J(SC)= 19.167 mA cm(-2),V(OC)= 0.736 V,FF = 0.711,总功率转换效率eta = 10.17%。
Porphyrin Cosensitization for a Photovoltaic Efficiency of 11.5%: A Record for Non-Ruthenium Solar Cells Based on Iodine Electrolyte
Dye-sensitized solar cells (DSSCs) are promising for utilizing solar energy. To achieve high efficiencies, it is vital to synergistically improve the photocurrent (J(sc)) and the photovoltage (V-oc). In this respect, conjugation framework extension and cosensitization are effective for improving the absorption and the J(sc), which, however, is usually accompanied by undesirably decreased V-oc. Herein, based on a rationally optimized porphyrin dye, we develop a targeted coadsorption/cosensitization approach for systematically improving the V-oc from 645 to 727, 746, and 760 mV, with synergistical J(sc) enhancement from 18.83 to 20.33 mA cm(-2). Thus, the efficiency has been dramatically enhanced to 11.5%, which keeps the record for nonruthenium DSSCs using the I-2/I-3(-) electrolyte. These results compose an alternative approach for developing highly efficient DSSCs with relatively high V-oc using traditional iodine electrolyte.