Toward Optimization of Oligothiophene Antennas: New Ruthenium Sensitizers with Excellent Performance for Dye-Sensitized Solar Cells
作者:Jen-Fu Yin、Jian-Ging Chen、Zong-Zhan Lu、Kuo-Chuan Ho、Hong-Cheu Lin、Kuang-Lieh Lu
DOI:10.1021/cm100770x
日期:2010.8.10
This paper reports on the design and synthesis of three new ruthenium sensitizers, as well as the optimization of their linear or dendritic light-harvesting oligothiophene antennas to achieve superior device performance. The three new ruthenium sensitizers, [Ru(dcbpy)(obtip)(NCS)(2)] (JF-5, dcbpy = 4,4'-dicarboxylic obtip = 2-(5-octyl-(2,2'-bithiophen)-5'-yl)-1H-imidazo[4,51][1,10]-phenanthroline), [Ru(dcbpy)(ottip)(NCS)(2)] (JF-6, ottip = 2-(5-octyl-2,2',5',2 ''-terthiophen)-5 ''-yl)-1H-imidazo[4,5-f][1,10]-phenanthroline), and [Ru(dcbpy)(dottip)(NCS)(2)] (JF-7, dottip = di-(5-octylthiophen-2-ypthiophen-5-yl)-1H-imidazo[4,5-f][1,10]phenanthroline), were synthesized in a typical one-pot reaction. The ruthenium sensitizer JF-5 incorporating a linear and planar 2,2'-bithiophene antenna showed the best DSCs performance (9.5%; compared to N3, 8.8%). The difference in the performance of these sensitizers demonstrates that elongating the linear and planar light-harvesting antenna result in an enhancement in MLCT intensity, but a reduction in the quantity of dye-loading. This finding not only permitted the power-conversion efficiency in ruthenium sensitizers containing oligothiophene antennas to be optimized, but also points to a promising direction for molecule engineering in DSCs.