Zhang, Y;
Payne, DT;
Pang, CL;
Cacho, C;
Chapman, RT;
Springate, E;
Fielding, HH;
(2019)
State-Selective Dynamics of TiO2 Charge-Carrier Trapping and Recombination.
Journal of Physical Chemistry Letters
, 10
(17)
pp. 5265-5270.
10.1021/acs.jpclett.9b02153.
Preview |
Text
JPCLett5265.pdf - Published Version Download (2MB) | Preview |
Preview |
Text
JPCLett5265SI.pdf - Published Version Download (478kB) | Preview |
Abstract
Time-resolved pump-probe photoemission spectroscopy has been used to study the dynamics of charge-carrier recombination and trapping on hydroxylated rutile TiO2(110). Two types of pump excitation were employed, one in the infrared (IR) (0.95 eV) and the other in the ultraviolet (UV) (3.5 eV) region. With IR excitation, electrons associated with defects are excited into the bottom of the conduction band from the polaronic states within the band gap, which are retrapped within 45 ± 10 fs. Under UV excitation, the electrons in these band-gap states (BGSs) and valence-band electrons are excited into the conduction band. In addition to the fast polaron trapping observed with IR excitation, we also observe a long lifetime (∼1 ps) component for both the depletion of hot electrons at the bottom of the conduction band and the refilling of the BGS. This points to a BGS-mediated recombination process with a picosecond lifetime.
Type: | Article |
---|---|
Title: | State-Selective Dynamics of TiO2 Charge-Carrier Trapping and Recombination |
Location: | United States |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1021/acs.jpclett.9b02153 |
Publisher version: | https://doi.org/10.1021/acs.jpclett.9b02153 |
Language: | English |
Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
URI: | https://discovery.ucl.ac.uk/id/eprint/10081604 |
Archive Staff Only
View Item |