DFT-INDO/S modeling of new high molar extinction coefficient charge-transfer sensitizers for solar cell applications.
DFT-INDO/S modeling of new high molar extinction coefficient charge-transfer sensitizers for solar cell applications.
复制标题
DOI：
10.1021/ic051727x
复制
发表时间：
2006-01
影响因子：
4.6
通讯作者：
M. Nazeeruddin;Qing Wang;L. Cevey;Viviane Aranyos;P. Liska;E. Figgemeier;C. Klein;N. Hirata;S. Koops;S. Haque;J. Durrant;A. Hagfeldt;A. Lever;M. Grätzel
中科院分区：
文献类型：
--
作者：
M. Nazeeruddin;Qing Wang;L. Cevey;Viviane Aranyos;P. Liska;E. Figgemeier;C. Klein;N. Hirata;S. Koops;S. Haque;J. Durrant;A. Hagfeldt;A. Lever;M. Grätzel
合成了一种新的Ru(II)配合物四丁基铵[Ru(4-羧酸acid-4‘-carboxylate-2，2’-bipyridine)(4，4‘-di(2-(3，6-dimethoxyphenyl)ethenyl)-2，2’-bipyridine)(NCS)(2)](N945H)])，并用分析、光谱和电化学技术对其进行了表征。在可见光区，N945H增敏剂的吸收光谱以金属-配体电荷转移(MLCT)跃迁为主，最低允许的MLCT谱带出现在25380和18180 cm(-1)。它们的摩尔消光系数分别为34500和18900M(-1)cm(-1)，并显著高于标准敏化剂顺-二硫氰基二(4，4‘-二羧酸-2，2’-联吡啶)Ru(II)的摩尔消光系数。用INDO/S和密度泛函理论研究了N945H和N945吸附在二氧化钛上的电学和光学性质。计算指出，前三个前线填充轨道基本上具有Ru 4d(八面体中的t(2g))性质，相当大的贡献来自于NCS配体轨道。最重要的是，计算表明，在结合了TiO(2)的N945敏化剂中，激发将电荷引导到结合在TiO(2)表面的羧基联吡啶配体中。用0.60M丁基甲基咪唑碘化物、0.03MI(2)、0.10M硫氰酸胍和0.50M叔丁基吡啶组成的电解液(体积比=85：15)，N945增感剂的光伏数据显示，短路光电流密度为16.50+/-0.2 mA cm(-2)，开路电压为790+/-30 mV，填充因子为0.72+/-0.03，对应于标准AM(空气质量)1.5阳光下9.6%的总转换效率。并在80℃的光热浸泡下表现出稳定的性能。
A new ruthenium(II) complex, tetrabutylammonium [ruthenium (4-carboxylic acid-4'-carboxylate-2,2'-bipyridine)(4,4'-di(2-(3,6-dimethoxyphenyl)ethenyl)-2,2'-bipyridine)(NCS)(2)] (N945H), was synthesized and characterized by analytical, spectroscopic, and electrochemical techniques. The absorption spectrum of the N945H sensitizer is dominated by metal-to-ligand charge-transfer (MLCT) transitions in the visible region, with the lowest allowed MLCT bands appearing at 25 380 and 18 180 cm(-1). The molar extinction coefficients of these bands are 34 500 and 18 900 M(-1) cm(-1), respectively, and are significantly higher when compared to than those of the standard sensitizer cis-dithiocyanatobis(4,4'-dicarboxylic acid-2,2'-bipyridine)ruthenium(II). An INDO/S and density functional theory study of the electronic and optical properties of N945H and of N945 adsorbed on TiO(2) was performed. The calculations point out that the top three frontier-filled orbitals have essentially ruthenium 4d (t(2g) in the octahedral group) character with sizable contribution coming from the NCS ligand orbitals. Most critically the calculations reveal that, in the TiO(2)-bound N945 sensitizer, excitation directs charge into the carboxylbipyridine ligand bound to the TiO(2) surface. The photovoltaic data of the N945 sensitizer using an electrolyte containing 0.60 M butylmethylimidazolium iodide, 0.03 M I(2), 0.10 M guanidinium thiocyanate, and 0.50 M tert-butylpyridine in a mixture of acetonitrile and valeronitrile (volume ratio = 85:15) exhibited a short-circuit photocurrent density of 16.50 +/- 0.2 mA cm(-2), an open-circuit voltage of 790 +/- 30 mV, and a fill factor of 0.72 +/- 0.03, corresponding to an overall conversion efficiency of 9.6% under standard AM (air mass) 1.5 sunlight, and demonstrated a stable performance under light and heat soaking at 80 degrees C.