4.8 Article

Dynamics of Photoexcited Small Polarons in Transition-Metal Oxides

期刊

JOURNAL OF PHYSICAL CHEMISTRY LETTERS
卷 12, 期 9, 页码 2191-2198

出版社

AMER CHEMICAL SOC
DOI: 10.1021/acs.jpclett.1c00003

关键词

-

资金

  1. National Key Foundation of China, Department of Science and Technology [2016YFA0200604, 2017YFA0204904]
  2. National Natural Science Foundation of China (NSFC) [11620101003, 11974322, 11704363]
  3. Anhui Initiative in Quantum Information Technologies [AHY090300]
  4. U.S. Department of Energy [DE-SC0014429]
  5. DOE Office of Biological and Environmental Research
  6. Supercomputing Center at USTC

向作者/读者索取更多资源

The dynamics of small polarons induced by photoexcitation in rutile TiO2 were investigated using ab initio nonadiabatic molecular dynamics simulation, revealing significant differences in polaron formation, migration, and quenching at different temperatures. At low temperature, the polaron is localized on a single Ti atom and quenches slowly, while at increased temperature, thermal phonon excitation stimulates polaron hopping and delocalization, leading to fast polaron quenching within 200 ps.
The dynamics of photoexcited polarons in transition-metal oxides (TMOs), including their formation, migration, and quenching, plays an important role in photocatalysis and photovoltaics. Taking rutile TiO2 as a prototypical system, we use ab initio nonadiabatic molecular dynamics simulation to investigate the dynamics of small polarons induced by photoexcitation at different temperatures. The photoexcited electron is trapped by the distortion of the surrounding lattice and forms a small polaron within tens of femtoseconds. Polaron migration among Ti atoms is strongly correlated with quenching through an electron-hole (e-h) recombination process. At low temperature, the polaron is localized on a single Ti atom and polaron quenching occurs within several nanoseconds. At increased temperature, as under solar cell operating conditions, thermal phonon excitation stimulates the hopping and delocalization of polarons, which induces fast polaron quenching through the e-h recombination within 200 ps. Our study proves that e-h recombination centers can be formed by photoexcited polarons, which provides new insights to understand the efficiency bottleneck of photocatalysis and photovoltaics in TMOs.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.8
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据