High Photoconductive Response of Gas-Sensitized Porous Nanocrystalline TiO2 Film in Formaldehyde Ambience and Carrier Transport Kinetics

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• 作者：Shasha Zhang ; Changsheng Xie ; Zhijun Zou ; Li Yang ; Huayao Li ; Shunping Zhang
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：September 20, 2012
• 年：2012
• 卷：116
• 期：37
• 页码：19673-19681
• 全文大小：482K
• 年卷期：v.116,no.37(September 20, 2012)
• ISSN：1932-7455

文摘

We propose a gas-sensitized porous nanocrystalline TiO₂ film with a potential application in photovoltaic devices and report about the systematic photoconductivity study of it. The quantitative results show that the gas-sensitized TiO₂ film in formaldehyde atmosphere exhibits much higher photoconductivity (3鈥? orders of magnitude) and longer carrier lifetime than usual. The intriguing performance of the gas-sensitized TiO₂ film indicates the distinct charge carrier transport kinetic courses, whose contributions to the photoconductivity are shown in a designed flowchart. From the flowchart, it is clearly found that two electron loss processes, recombination and electron scavenging, are suppressed for the gas-sensitized TiO₂ film in formaldehyde gas, leading to large improvements of photoconductivity and carrier lifetime. The results provide the potential of improving efficiency of photovoltaic devices, and measuring photoconductivity under target gas appears to be a useful tool for research on photocatalytic and photoelectrical processes.