Trapping dynamics of electrons and holes in a nanocrystalline TiO2 film revealed by femtosecond visible/near-infrared transient absorption spectroscopy

被引：78

作者：

Tamaki, Y ^{[1
]}

Furube, A ^{[1
]}

Katoh, R ^{[1
]}

Murai, M ^{[1
]}

Hara, K ^{[1
]}

Arakawa, H ^{[1
]}

Tachiya, M ^{[1
]}

机构：

[1] Natl Inst Adv Ind Sci & Technol AIST, Tsukuba, Ibaraki 3058565, Japan

来源：

COMPTES RENDUS CHIMIE | 2006年 / 9卷 / 02期

关键词：

TiO2; hole; electron; trapping; cooling; transient absorption;

D O I：

10.1016/j.crci.2005.05.018

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The trapping dynamics of electrons and holes in TiO2 nanocrystlline films excited by ultraviolet laser pulses (266-nm wavelength) were studied with femtosecond visible/near-infrared transient absorption spectroscopy. UV irradiations of the TiO2 film generated hot carriers in the conduction and valence bands. The formation rate of deeply trapped holes was estimated to be 200 +/- 50 fs. The rate was limited by intraband relaxation (cooling) of hot holes. The spectral shift of the transient absorption indicated that trapped holes relax from shallow sites to deep ones. This relaxation was occurring more than 100 ps after photoexcitation.

引用

页码：268 / 274

页数：7

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