Extending the photoresponse of TiO2 to the visible light region: photoelectrochemical behavior of TiO2 thin films prepared by the radio frequency magnetron sputtering deposition method.
Extending the photoresponse of TiO2 to the visible light region: photoelectrochemical behavior of TiO2 thin films prepared by the radio frequency magnetron sputtering deposition method.
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DOI：
10.1021/jp058262g
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发表时间：
2006-02
期刊：
影响因子：
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通讯作者：
H. Kikuchi;M. Kitano;M. Takeuchi;M. Matsuoka;M. Anpo;P. Kamat
中科院分区：
文献类型：
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作者：
H. Kikuchi;M. Kitano;M. Takeuchi;M. Matsuoka;M. Anpo;P. Kamat
采用射频磁控溅射（RF-MS）方法制备了TiO（2）薄膜，发现其在可见光区具有增强的光电化学响应。通过在沉积步骤期间控制温度和气态介质，可以控制这些膜的性质。将溅射的TiO（2）薄膜的光电化学行为与商业TiO（2）样品的光电化学行为进行了比较，并且溅射的薄膜显示出比商业TiO（2）样品更高的入射光子到电荷载流子产生效率（在350 nm处IPCE为12.6%）以及功率转换效率（在1.84 mW/cm（2）处为0.33%）。飞秒瞬态吸收光谱实验已经揭示了光生电子和空穴的主要部分在几皮秒内复合，从而限制了光电流产生效率。在本研究中获得的机制的见解应有助于设计半导体纳米结构，将最大限度地提高电荷分离效率，并扩展到可见光区的大带隙半导体TiO（2）的响应。
TiO(2) thin films prepared by a radio frequency magnetron sputtering (RF-MS) deposition method were found to show an enhanced photoelectrochemical response in the visible light region. By controlling the temperature and the gaseous medium during the deposition step, it was possible to control the properties of these films. The photoelectrochemical behavior of the sputtered TiO(2) thin films was compared with that of a commercial TiO(2) sample, and the sputtered films showed higher incident photon to the charge carrier generation efficiency (IPCE of 12.6% at 350 nm) as well as power conversion efficiency (0.33% at 1.84 mW/cm(2)) than the commercial TiO(2) sample. Femtosecond transient absorption spectroscopy experiments have revealed that a major fraction of photogenerated electrons and holes recombine within a few picoseconds, thus limiting photocurrent generation efficiency. The mechanistic insights obtained in the present study should aid in designing semiconductor nanostructures that will maximize the charge separation efficiency and extend the response of the large band gap semiconductor TiO(2) into visible light regions.