利用MEVVA技术分别将金属Fe、Ni、Ag离子注入进DSSCs结构中作为电荷传输层的TiO2膜,表征了各金属离子注入后TiO2膜表面形貌及晶相结构,研究了DSSCs注入前后光电性能及电池内部界面的电荷传输变化。能带理论分析显示,金属离子注入后,TiO2能带结构发生变化,并在其禁带中引入了杂质能级,不仅优化了TiO2导带与染料LUMO能级匹配度,而且杂质能级为电荷的传输提供了额外传输"通道",从而降低了电荷传输过程中的复合率。DSSCs光电性能测试结果显示,与未注入的DSSCs相比,Fe、Ni、Ag离子注入DSSCs的光电转化率分别提高了13.6%、12.7%、34.2%。
Fe, Ni, Ag ions-implanted DSSCs were successfully prepared via MEWA technology. Surface morphology and crystal structure were characterized by SEM and XRD, and photoelectric properties and charge transport were measured by I-V test and electrochemical impedance, respectively. According to band theory, the band structure of TiO2 was changed and impurity levels were introduced in band gap after metal ions implantation, which optimized the matching rate between the conduction band of TiO2 and LUMO levels of dye. Moreover, the impurity level provided extra "channel" for charge transferring, which reduced charge recombination. Compared with un-implanted cells, thephotoelectric conversion efficiencies of Fe, Ni, Ag ions implanted DSSCs were improved by 13.6%, 12. 7% and 34. 2%, respectively.