Scholarlink

<p>Electrochromism is the change of color of a material due to double insertion of electrons and cations. In this study, the nature of the electrochromic process in anatase TiO<sub>2</sub> thin films has been explored by considering the way by which light absorbed. TiO<sub>2</sub> anatase thin films have been deposited by MOCVD at 350&#xa0;°C at a total pressure 15 torr. Double insertion of Li ions and electrons has been carried out electrochemically. The mole fraction of the inserted Li ions in the TiO<sub>2</sub> film was 28%. In situ transmittance measurements have been done using UV–Vis-NIR spectrophotometry. Blue shift in the transmittance spectra of the colored film has been detected. Some of the Ti<sup>+4</sup> ions have been reduced to Ti<sup>+3</sup> due to double insertion as seen from XPS measurements. Two absorption bands appeared which can be assigned to be polaronic. The polarons binding energies and radii have been calculated by fitting the absorption coefficient. According to the obtained data and other studies the electronic structure changes cannot be explained according to the rigid band model. Band gap broadening supposed to take place.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Absorption polaronic bands and band gap broadening in TiO2 thin films

  • 期刊论文

  • 发表日期：

    2025年10月2日

查看全文
  • Z. S. Khalifa,
  • Mohammed A. Hussein

摘要

Electrochromism is the change of color of a material due to double insertion of electrons and cations. In this study, the nature of the electrochromic process in anatase TiO2 thin films has been explored by considering the way by which light absorbed. TiO2 anatase thin films have been deposited by MOCVD at 350 °C at a total pressure 15 torr. Double insertion of Li ions and electrons has been carried out electrochemically. The mole fraction of the inserted Li ions in the TiO2 film was 28%. In situ transmittance measurements have been done using UV–Vis-NIR spectrophotometry. Blue shift in the transmittance spectra of the colored film has been detected. Some of the Ti+4 ions have been reduced to Ti+3 due to double insertion as seen from XPS measurements. Two absorption bands appeared which can be assigned to be polaronic. The polarons binding energies and radii have been calculated by fitting the absorption coefficient. According to the obtained data and other studies the electronic structure changes cannot be explained according to the rigid band model. Band gap broadening supposed to take place.