TiO2表面质子化对染料敏化太阳能电池性能及吸附染料稳定性的影响

采用致密平整TiO₂薄膜作为染料敏化太阳能电池光电极，并研究了HCl处理表面质子化对电池性能的影响. 结果表明，HCl处理后电池的短路电流显著提升，电池的开路电压则有轻微的下降，电池电流提升了31%，而能量转化效率则提升了25%. 这是因为TiO₂的表面质子化增强了吸附染料与TiO₂间的电学耦合，提高了染料中激发电子向TiO₂导带的注入速率. 而电压的下降，一方面是由于质子化会引起TiO₂导带能级

Effect of Surface Protonation on Device Performance and Dye Stability of Dye-sensitized TiO2 Solar Cell

A flat thin TiO₂ film was employed as the photo-electrode of a dye sensitized solar cell (DSSC), on which only a geometrical mono-layer of dye was attached. The effect of sur-face protonation by HCl chemical treatment on the performance of DSSCs was studied. The results showed that the short-circuit current Jsc increased significantly upon the HCl treatment, while the open-circuit voltage Voc decreased slightly. Compared to the untreated DSSC, the Jsc and energy conversion efficiency was increased by 31% and 25%, respectively, for the 1 mol/L HCl treated cell. TiO₂ surface protonation improved electronic coupling between the chemisorbed dye and the TiO₂ surface, resulting in an enhanced electron in-jection. The decreased open-circuit voltage after TiO₂ surface protonation was mainly due to the TiO₂ conduction band edge downshift and was partially caused by increased electron recombination with the electrolyte. In situ Raman degradation study showed that the dye stability was improved after the TiO₂ surface protonation. The increased dye stability was contributed by the increased electron injection and electron back reaction with the electrolyte under the open-circuit condition.