Details
| Original language | English |
|---|---|
| Pages (from-to) | 13979-13985 |
| Number of pages | 7 |
| Journal | The Journal of Physical Chemistry C |
| Volume | 122 |
| Issue number | 25 |
| Early online date | 17 Apr 2018 |
| Publication status | Published - 28 Jun 2018 |
Abstract
During transient absorption spectroscopic investigations we found that the intensity of the transient absorption signal of the trapped holes monitored in the microsecond time domain drastically increases at high excitation laser intensity. This increase has been related to the presence of long-lived Ti 3+ centers formed upon high laser exposure via a surface reorganization. The Coulomb interaction of the trapped holes with long-lived Ti 3+ centers leads to an increased absorption coefficient of the former resulting in much higher transient absorption signals below 450 nm rather than in the wavelength region above where the trapped electrons absorb. The surface reorganization induced via the excitation source can be avoided in the case of anatase if the measurements are conducted at low laser intensities, while in the case of rutile already at low excitation conditions the transient absorption enhancement of the trapped holes occurs.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Energy(all)
- General Energy
- Chemistry(all)
- Physical and Theoretical Chemistry
- Materials Science(all)
- Surfaces, Coatings and Films
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In: The Journal of Physical Chemistry C, Vol. 122, No. 25, 28.06.2018, p. 13979-13985.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Strong Transient Absorption of Trapped Holes in Anatase and Rutile TiO2 at High Laser Intensities
AU - Schneider, Jenny
AU - Bahnemann, Detlef
N1 - Copyright © 2018 American Chemical Society
PY - 2018/6/28
Y1 - 2018/6/28
N2 - During transient absorption spectroscopic investigations we found that the intensity of the transient absorption signal of the trapped holes monitored in the microsecond time domain drastically increases at high excitation laser intensity. This increase has been related to the presence of long-lived Ti 3+ centers formed upon high laser exposure via a surface reorganization. The Coulomb interaction of the trapped holes with long-lived Ti 3+ centers leads to an increased absorption coefficient of the former resulting in much higher transient absorption signals below 450 nm rather than in the wavelength region above where the trapped electrons absorb. The surface reorganization induced via the excitation source can be avoided in the case of anatase if the measurements are conducted at low laser intensities, while in the case of rutile already at low excitation conditions the transient absorption enhancement of the trapped holes occurs.
AB - During transient absorption spectroscopic investigations we found that the intensity of the transient absorption signal of the trapped holes monitored in the microsecond time domain drastically increases at high excitation laser intensity. This increase has been related to the presence of long-lived Ti 3+ centers formed upon high laser exposure via a surface reorganization. The Coulomb interaction of the trapped holes with long-lived Ti 3+ centers leads to an increased absorption coefficient of the former resulting in much higher transient absorption signals below 450 nm rather than in the wavelength region above where the trapped electrons absorb. The surface reorganization induced via the excitation source can be avoided in the case of anatase if the measurements are conducted at low laser intensities, while in the case of rutile already at low excitation conditions the transient absorption enhancement of the trapped holes occurs.
UR - http://www.scopus.com/inward/record.url?scp=85046450525&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.8b01109
DO - 10.1021/acs.jpcc.8b01109
M3 - Article
VL - 122
SP - 13979
EP - 13985
JO - The Journal of Physical Chemistry C
JF - The Journal of Physical Chemistry C
SN - 1932-7455
IS - 25
ER -