物理化学学报 >> 2010, Vol. 26 >> Issue (02): 403-408.doi: 10.3866/PKU.WHXB20100213

光化学与光谱 上一篇    下一篇

介孔掺镧纳米晶TiO2瞬态光伏与表面光声特性

李葵英, 刘通, 周冰晶, 魏赛玲, 杨伟勇   

  1. 燕山大学亚稳材料制备技术与科学国家重点实验室, 河北 秦皇岛 066004
  • 收稿日期:2009-07-02 修回日期:2009-11-16 发布日期:2010-01-26
  • 通讯作者: 李葵英 E-mail:kuiyingli@ysu.edu.cn

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

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摘要：

结合瞬态光伏与表面光声技术, 研究介孔掺镧nano-TiO2光生载流子分离与复合过程及其能量转换机制. 结果表明: 锐钛矿中两种不同光伏特性的缺陷态具有光生载流子扩散距离短, 复合速度快的特点; 镧掺杂增加体缺陷态对于光伏效应的贡献, 但在某种程度上抑制主带隙的电荷分离; 模板剂种类对于主带隙电子-空穴对的分离与复合过程, 以及亚带隙无辐射跃迁引起的晶格振动均有显著的影响. 结果证实了样品表面光声与瞬态光伏现象之间存在明显的能量互补关系.

关键词: TiO2, 介孔纳米晶, 模板剂, 镧掺杂, 瞬态光电压谱, 表面光声光谱

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