Acta Chimica Sinica ›› 2006, Vol. 64 ›› Issue (17): 1761-1764.     Next Articles

Original Articles


付姚; 曹望和*; 田莹   

  1. (大连海事大学光电子技术研究所 大连 116026)
  • 投稿日期:2006-01-11 修回日期:2006-04-07 发布日期:2006-09-14
  • 通讯作者: 曹望和

Study on Transport Properties of Photo-generated Carriers in Nanocrystalline TiO2 Film Electrode

FU Yao; CAO Wang-He*; TIAN Ying   

  1. (Optoelectronic Technology Institute, Dalian Maritime University, Dalian 116026)
  • Received:2006-01-11 Revised:2006-04-07 Published:2006-09-14
  • Contact: CAO Wang-He

The anatase-type nanocrystalline TiO2 film electrode with characteristics of uniformity and transparency was prepared by sol-gel method. The transport properties of photo-generated carriers in the prepared electrode contacted with aqueous electrolyte were studied by transient photocurrent spectra. The results show that there exist two kinds of surface states on the TiO2/electrolyte interface. One (shallow surface state), created by chemisorbed oxygen molecule, locates in the range of 0.5 eV which is just below the conduction band, and its electron-capturing onset potential is about -0.4 V. The other (deep surface state), formed by lattice oxygen ion, locates near the middle of the band gap, and plays a role as a center for electron-hole surface recombination. The electron-capturing efficiencies of these two surface states are related to the pH value of the electrolyte and the electrode potential (U). A potential higher than 0.4 V can remarkably increase the transfer rate of photo-generated carriers and make a downward shift of the TiO2 film’s Fermi level (EFn), which could effectively suppress the surface-capturing process of photo-generated electrons, and improve the intensity and stability of the anode photocurrent.

Key words: inorganic nonmetallic material, transport property of photogenerated carrier, photoelectric property, nanocrystalline TiO2 film electrode