Study on dynamic properties of the photoexcited charge carriers at anatase TiO2 nanowires/fluorine doped tin oxide interface
Study on dynamic properties of the photoexcited charge carriers at anatase TiO2 nanowires/fluorine doped tin oxide interface
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锐钛矿型TiO2纳米线/氟掺杂氧化锡界面光生载流子动态特性研究
DOI：
10.1016/j.jcis.2017.04.075
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发表时间：
2017
影响因子：
9.9
通讯作者：
Xie Tengfeng
中科院分区：
文献类型：
--
作者：
Qiu Qingqing;Xu Lingling;Wang Dejun;Lin Yanhong;Xie Tengfeng
采用表面光电压（SPV）和瞬态光电压（TPV）技术研究了量子点敏化的TiO 2纳米线阵列（NWAs）和TiO 2纳米线阵列薄膜的TiO 2薄膜/掺氟氧化锡（FTO）界面上的光激发电子转移动力学.当激光束从正面照明和背面照明入射时，得到不同的SPV和TPV响应。基于功函数值的计算结果表明，正面光照下，扩散是TiO 2 NWAs薄膜和量子点敏化TiO 2 NWAs薄膜中光激发电荷分离和转移的主要途径.在背照光下，量子点敏化的TiO_2纳米晶薄膜和量子点敏化的TiO_2纳米晶薄膜在FTO/TiO_2薄膜界面处的内建电场作用下，光激发电荷发生漂移分离。另外，在背照条件下，CdS/CdSe量子点和TiO_2纳米线阵列的内建电场和能带结构导致了CdS/CdSe量子点敏化TiO_2纳米线阵列/FTO薄膜中光激发电荷的分离和转移。随着光照强度的增加，内建电场对量子点敏化的TiO 2 NWAs薄膜中光激发电荷的分离和转移的影响逐渐减小。
The photoexcited electrons transfer dynamics at the TiO2film/fluorine doped tin oxide (FTO) interface of anatase TiO2nanowire arrays (NWAs) and QD-sensitized TiO2NWAs films have been studied by using surface photovoltage (SPV) and transient photovoltage (TPV) techniques. Various SPV and TPV responses were obtained when the laser beam was incident from the front side illumination and back side illumination. Based on the work function values of anatase TiO2NWAs and FTO, the results indicate that diffusion is the major way for the separation and transfer of the photoexcited charge in the both anatase TiO2NWAs and QD-sensitized TiO2NWAs films under front side illumination. And the photoexcited charge were separated by drift under the built-in electric field at the TiO2film/FTO interface for anatase TiO2NWAs and QD-sensitized TiO2NWAs films under back side illumination. In addition, under back side illumination the built-in electric field and band structure of CdS/CdSe QDs and anatase TiO2NWAs lead to the separation and transfer of the photoexcited charge for CdS/CdSe QDs sensitized TiO2NWAs/FTO film. As the intensity of illumination increases, the effect of built-in electric field on the separation and transfer of the photoexcited charge in the QD-sensitized TiO2NWAs film decreases.