Direct Observation of Ultrafast Electron Injection from Coumarin 343 to TiO2 Nanoparticles by Femtosecond Infrared Spectroscopy

• DOI: 10.1021/jp981806c
• Publication Date: 2002-07-26T05:28:13Z
• Authors: Hirendra N. Ghosh; John B. Asbury; Tianquan Lian
• Keywords: 01 natural sciences; 0104 chemical sciences

Transient infrared (IR) absorption of injected electrons in colloidal TiO2 nanoparticles the 1900−2000 cm-1 region are measured by femtosecond IR spectroscopy. The direct detection with subpicosecond time resolution provides a new approach to study ultrafast interfacial electron transfer between semiconductor and molecular adsorbates. dynamics injection from sensitizers subsequent back-transfer relaxation correspond rise decay transient signal electrons. Using this technique, for coumarin 343 sensitized D2O is determined be 125 ± 25 fs. found different conduction band bulk crystal.