New ruthenium complexes (Ru[3+2+1]) bearing π-extended 4-methylstyryl terpyridine and unsymmetrical bipyridine ligands for DSSC applications
摘要:
Two novel heteroleptic Ru[3+2+1] sensitizers, 1 and 2, with unsymmetrical bipyridine as ancillary ligand and electron donating 4-methylstyryl group in the anchoring p-extended terpyridyl ligand were synthesized and characterized. DFT studies reveal that the lowest unoccupied molecular orbital (LUMO) is distributed over the terpyridine. The two new sensitizers showed an improvement in the molar extinction coefficient compared to reference standard N749 dye. Among the two new sensitizers, 1 exhibited maximum solar to electric conversion efficiency (eta) of 5.19% with short circuit current density of 14.032 mA cm (2), open circuit voltage of 0.520 V and fill factor of 0.712, under Air Mass (AM) 1.5 sunlight, while the reference N749 sensitized solar cell exhibited eta-value of 6.44%. (C) 2015 Elsevier B.V. All rights reserved.
根据用适度给电子的4-甲基苯乙烯基取代对吡啶基配体的分子设计策略,制备了一种新型的Ruπ扩展的吡啶基敏化剂,称为HIS-2。与黑色染料相比,HIS-2染料在600 nm处的金属至配体电荷转移(MLCT)吸收略有增加,而在UV区的π-π*吸收则很强。密度泛函理论计算表明,最低的未占据分子轨道(LUMO)分布在三联吡啶和4-甲基苯乙烯基部分上,这增强了光收集能力,适用于从染料到TiO 2的平稳电子注入导带。由于扩展的π共轭作用,HIS-2的入射光子-电转换效率谱在整个光谱范围内表现出比黑色染料更好的光响应。基于黑色染料的DSC器件在整体转换效率方面提供21.28 mA cm -2的短路电流(J SC),0.69 V的开路电压(V OC)和0.72的填充系数(FF) (η)为10.5%。相反,基于HIS-2的电池的J SC值较高,为23.07 mA cm -2,而V OC为0.68 V,FF为0