Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (02): 403-408.doi: 10.3866/PKU.WHXB20100213

• PHOTOCHEMISTRY AND SPECTROSCOPY • Previous Articles     Next Articles

Transient Photovoltaic and Surface Photoacoustic Characteristics of Mesoporous Crystalline La-doped TiO2 Nanoparticles

LI Kui-Ying, LIU Tong, ZHOU Bing-Jing, WEI Sai-Ling, YANG Wei-Yong   

  1. National Laboratory of Metastable Materials Manufacture Technology&Science, Yanshan University, Qinhuangdao 066004, Hebei Province, P. R. China
  • Received:2009-07-02 Revised:2009-11-16 Published:2010-01-26
  • Contact: LI Kui-Ying E-mail:kuiyingli@ysu.edu.cn

Abstract:

Transient photovoltaic and surface photoacoustic techniques were used to investigate the separation and recombination processes of photogenerated charge carriers and the mechanism of energy conversion for mesoporous La-doped nano-TiO2. Results indicate that two defect states with different photovoltage characteristics have a short diffusion distance and a fast recombination velocity for the electron hole pair; and that doped lanthanum increases the contribution of bulk defects to the photovoltaic effect, but inhibits the main bandgap charge separation to a certain extent. Additionally, we show that both the mechanism of separation and recombination of the main bandgap electron hole pair and the intensity of the lattice vibration resulting from the non-radioactive transition are highly dependent on the type of template. These experimental results confirm that an obvious energy balance relationship exists between transient photovoltaics and surface photoacoustic phenomena.

Key words: TiO2, Mesoporous nanocrystalline, Template, La-doped, Transient photovoltaic spectroscopy, Surface photoacoustic spectroscopy

MSC2000: 

  • O643