Enhanced light-harvesting capability by phenothiazine in ruthenium sensitizers with superior photovoltaic performance
作者:Jen-Fu Yin、Jian-Ging Chen、Jiann-T'suen Lin、Dibyendu Bhattacharya、Ying-Chan Hsu、Hong-Cheu Lin、Kuo-Chuan Ho、Kuang-Lieh Lu
DOI:10.1039/c1jm13178h
日期:——
This paper reports on the design and synthesis of two new ruthenium dyes [Ru(dcbpy)(potip)(NCS)2] (JF-3, dcbpy = 4,4′-dicarboxylic acid-2,2′-bipyridine, potip = 2-(4-(10H-phenothiazin-10-yl)-5-octylthiophen-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline, and [Ru(dcbpy)(dpotip)(NCS)2] (JF-4, dpotip = 2-(4-(N,N-diphenylamino)-5-octylthiophen-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline) that contain electron-donating phenothiazine-based or N,N-diphenylamino-based ancillary ligands. The ruthenium dye JF-3, in which an excellent electron-donating phenothiazine is incorporated, shows superior DSC performance (9.1%; compared to 8.8% for N3). A comparison of the electron-donating phenothiazine and N,N-diphenylamino groups utilized in the molecular architecture of ruthenium dyes demonstrates that the phenothiazine group efficiently increases the molar extinction coefficient of band II and also broadens that band in the UV-vis absorption spectrum, reduces device resistance, increases electron lifetime, and enhances power-conversion efficiency. This finding not only clarifies the significance of multifunctionalized design in the molecular architecture of ruthenium dyes, but also represents an alternative route for the introduction of an excellent electron-donating group for improving the light-harvesting characteristics of ruthenium dyes as well as DSC performance.
本论文报道了两种新型钌染料[Ru(dcbpy)(potip)(NCS)₂] (JF-3,dcbpy = 4,4'-二羧酸-2,2'-联吡啶,potip = 2-(4-(10H-吩噻嗪-10-基)-5-辛基噻吩-2-基)-1H-咪唑[4,5-f][1,10]菲罗啉,以及 [Ru(dcbpy)(dpotip)(NCS)₂] (JF-4,dpotip = 2-(4-(N,N-二苯基氨基)-5-辛基噻吩-2-基)-1H-咪唑[4,5-f][1,10]菲罗啉)的设计与合成,这两种染料包含具有电子给体性质的吩噻嗪基或N,N-二苯基氨基辅助配体。其中,含有优秀电子给体吩噻嗪的钌染料JF-3表现出优异的DSC性能(9.1%;相比之下,N3为8.8%)。通过对钌染料分子结构中使用的电子给体吩噻嗪和N,N-二苯基氨基基团的比较,表明吩噻嗪基团能有效增加带II的摩尔消光系数并拓宽其在紫外-可见吸收光谱中的带宽,降低器件电阻,延长电子寿命,并提高光电转换效率。这一发现不仅阐明了多官能化设计在钌染料分子结构中的重要意义,而且为引入优秀电子给体以改善钌染料的光捕获特性和DSC性能提供了替代途径。