Enhancement of carrier mobility by electrospun nanofibers of Nb-doped TiO2 in dye sensitized solar cells
Enhancement of carrier mobility by electrospun nanofibers of Nb-doped TiO2 in dye sensitized solar cells
复制标题
染料敏化太阳能电池中掺铌 TiO2 电纺纳米纤维增强载流子迁移率
DOI：
10.1016/j.electacta.2013.05.037
复制
发表时间：
2013
影响因子：
6.6
通讯作者：
Teruaki Nomiyama
中科院分区：
文献类型：
--
作者：
Yuji Horie;Tomomitsu Watanabe;Makoto Deguchi;Daisuke Asakura;Teruaki Nomiyama
将电纺TiO 2和Nb掺杂TiO 2（NTO）纳米纤维（ES-NF）作为导电剂添加到染料敏化太阳能电池（DSC）光电极中TiO 2介孔层中，考察了其对载流子迁移率和光伏特性的影响。制备了直径约为120 nm的TiO 2-NFs和NTO-NFs的非织造片材，并将它们的碎片混合到TiO 2介孔层中。将NTO和TiO 2的ES-NF混合后，短路电流密度Jsc分别提高了6%和8%。从脉冲激光激发的光电流瞬态谱中可以看出，光激发载流子在TiO 2介孔层中的扩散速度分别提高了70%和165%，而混合纳米纤维的含量很小，约为10vol%。此外，由于能带弯曲的光电流的增强也观察到在TiO 2/NTO的界面。电化学阻抗谱（EIS）表明，混合物使光电极的欧姆电阻降低了4%和15%。因此，NTO的ES-NF是一种良好的光致载流子在染料/TiO 2纳米粒子中聚集的导电剂。
The electrospun nanofibers (ES-NFs) of TiO2and Nb doped TiO2(NTO) were added to the TiO2mesoporous layer in the photoelectrode of dye sensitized solar cells (DSCs) as a conductive agent, and their effects to the carrier mobility and photovoltaic characteristics were examined. The nonwoven sheets of TiO2-NFs and NTO-NFs of which diameter was about 120nm were prepared, and their fragments were mixed into the TiO2mesoporous layer. By mixing ES-NFs of TiO2and NTO, the short-circuit current density Jscwas increased by 6% and 8%, respectively. From the time-transient spectra of photocurrent excited by a pulse laser irradiation, the diffusion velocity of photoexcited carriers in the TiO2mesoporous layer was found to be increased by 70% and 165%, while the amount of mixed NFs was small, ∼10vol%. Furthermore, the enhancement of photocurrent due to the band bending was also observed at the interface of TiO2/NTO. The electrochemical impedance spectra (EIS) showed that ohmic resistance of the photoelectrode was reduced by 4% and 15% by the mixture. Thus, it was found that ES-NFs of NTO are a good conductive agent for the accumulation of photoexcited carriers in dye/TiO2nanoparticles.