We have designed and synthesized a new thiocyante-free ruthenium complex containing 2,6-bis(1-methylbenzimidazol-2-yl)pyridine, coded as SPS-G3, and it has been used as an efficient photosensitizer for dye-sensitized solar cells (DSSCs). Upon sensitization of SPS-G3 on nanocrystalline TiO₂ film, the DSSC test cell yielded a large short-circuit photocurrent (16.15 mA cm^–2), an open circuit voltage of 0.52 V, and a fill factor (FF) of 0.72, resulting in an overall power conversion efficiency (PCE) of 6.04% under simulated AM 1.5 solar irradiation (100 mW cm^–2). DSSCs were prepared by adding various concentrations of multiwall carbon nanotubes (MWCNTs) (up to 0.5 wt %) into the TiO₂ nanoparticles. Optimization of MWCNT concentration (0.3 wt %) lead to PCE values as high as 7.76%, while the test cells employing pure TiO₂ photoanode obtained an efficiency of 6.04%. The results indicate that the PCE of MWCNTs/TiO₂ composite DSSCs are dependent on the quantity of MWCNTs loading on the photoanodes. A small amount (0.3 wt %) clearly enhances the PCE of DSSC, while the excessive MWCNT loading lowers the photovoltaic performance of the DSSC. The increase in the PCE has been attributed to the decrease in charge-transport resistance, charge-transport time, and electron lifetime, which are estimated from electrochemical impedance spectra.

中文翻译：

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2,6-双（1-甲基苯并咪唑-2-基）吡啶：在染料敏化太阳能电池中高效无硫氰酸盐钌敏化剂的新型辅助配体

我们已经设计并合成了一种新的不含硫氰酸盐的钌配合物，其中含有2,6-双（1-甲基苯并咪唑-2-基）吡啶，编码为SPS-G3，并且已被用作染料敏化太阳能电池的有效光敏剂。 （DSSC）。在纳米晶TiO ₂薄膜上对SPS-G3进行敏化后，DSSC测试电池产生了大的短路光电流（16.15 mA cm ^–2），开路电压为0.52 V和填充系数（FF）为0.72，从而在模拟的AM 1.5太阳辐射（100 mW cm ^–2）下，总功率转换效率（PCE）为6.04％。通过将各种浓度的多壁碳纳米管（MWCNT）（最高0.5 wt％）添加到TiO _2中来制备DSSC纳米粒子。MWCNT浓度（0.3 wt％）的优化导致PCE值高达7.76％，而采用纯TiO _2光阳极的测试电池的效率为6.04％。结果表明，MWCNTs / TiO ₂复合DSSCs的PCE取决于负载在光阳极上的MWCNTs的数量。少量（0.3 wt％）明显增强了DSSC的PCE，而过多的MWCNT负载降低了DSSC的光伏性能。PCE的增加归因于电荷传输电阻，电荷传输时间和电子寿命的减少，这是根据电化学阻抗谱估计的。