Nb2O5包覆对TiO2纳米阵列/上转换发光复合结构柔性染料敏化太阳能电池性能的影响

采用水热法与旋涂法, 成功制备出基于钛网基底的TiO₂纳米线阵列/Yb-Er-F掺杂TiO₂上转换发光纳米粒子(TNWAs/YEF-TiO₂-UCNPs)复合结构光阳极, 并将其组装成柔性染料敏化太阳能电池(DSSC)。探讨了Yb-Er-F掺杂TiO₂上转换发光纳米粒子的光学性能对复合结构DSSC光电转换性能的影响, 在此基础上系统研究了不同NbCl₅浓度包覆对复合结构形貌和DSSCs性能的影响。结果表明：Yb-Er-F掺杂TiO₂上转换发光纳米粒子的引入可以增大光阳极的入射光利用范围, 但同时也会增加其内部的电子复合。通过Nb₂O₅纳米粒子层的包覆可以在半导体/电解液界面形成能量势垒, 增加复合阻抗R_rec, 抑制电子复合; 提高电子收集效率η_ec和光生电子寿命τ_e, 进一步增大短路电流和开路电位, 最终提高电池的光电转换效率。采用20 mmol/L的NbCl₅乙醇溶液旋涂制备的Nb₂O₅@TNWAs/YEF-TiO₂-UCNPs复合结构柔性DSSC获得了最佳的光电转换效率(6.89%), 比未经包覆的TNWAs/YEF-TiO₂-UCNPs复合结构提升了24.3%。

Nb2O5 Coating on the Performance of Flexible Dye Sensitized Solar Cell Based on TiO2 Nanoarrays/Upconversion Luminescence Composite Structure

By using hydrothermal and spin-coating method, Ti mesh supported composite structure, TiO₂ nanowire arrays/Yb-Er-F doped TiO₂ upconversion luminescence nanoparticles (TNWAs/YEF-TiO₂-UCNPs), was synthesized and assembled into flexible dye-sensitized solar cell (DSSC). The effect of YEF-TiO₂-UCNPs optical property on the power conversion efficiency (PCE) of this device was studied. In addition, the influence of NbCl₅ solution coating on morphology and performance of flexible DSSC was also investigated in detail. It is shown that the YEF-TiO₂- UCNPs could expand the range of incident light utilization, in the meantime, however, increase the electron recombination in photoanode. Nb₂O₅ coating layer served as an energy barrier at the semiconductor/electrolyte interface, increased the composite resistance R_rec to inhibit electron recombination, improved the electron collection efficiency η_ec and photogenerated electron lifetime τ_e, then elevated the short circuit current and the open circuit voltage, finally enhanced the performance of DSSC. The Nb₂O₅@TNWAs/YEF-TiO₂-UCNPs composite structured DSSC achieved the best PCE of 6.89% with 20 mmol/L NbCl₅ ethanol solution coating, increased 24.3% compared with the uncoated blank device.