TY  - JOUR
AU  - Uemura, Yohei
AU  - Yamamoto, Kohei
AU  - Niwa, Yasuhiro
AU  - Buttiens, Thomas
AU  - Elnaggar, Hebatalla
AU  - Wang, Ru-pan
AU  - Lazemi, Masoud
AU  - de Groot, Frank
AU  - Katayama, Tetsuo
AU  - Yabashi, Makina
AU  - Milne, Christopher J.
AU  - Yokoyama, Toshihiko
TI  - Electronic and Structural Relaxation of Photoexcited WO<sub>3</sub> Observed by Femtosecond Resonant X-ray Emission Spectra
JO  - The journal of physical chemistry letters
VL  - 16
IS  - 24
SN  - 1948-7185
CY  - Washington, DC
PB  - ACS
M1  - PUBDB-2025-02025
SP  - 6138 - 6145
PY  - 2025
AB  - Photoexcited states of tungsten trioxide (WO<sub>3</sub>) were observed using femtosecond high-energy-resolution fluorescence detection X-ray Absorption Spectra (HERFD-XAS) and resonant X-ray emission spectra (RXES). In the initial state of the photoexcitation (∼100 fs), the W L<sub>3</sub> edge XAS shifts to lower energy and the energy levels of the t<sub>2g</sub> and e<sub>g</sub> peaks are modulated due to the photoexcited electrons in the conduction band. The electronic state of the photoexcited W atoms is modified by 500 fs. The crystal field splitting between the t<sub>2g</sub> and e<sub>g</sub> peaks shrinks by 500 fs, which indicates local structural changes around the W atoms due to the formation of polarons. HERFD-XAS and RXES provide more details about the early state of the photoexcited states of WO<sub>3</sub>. This work demonstrates that the detailed dynamics of 5d elements in the femtosecond range can be addressed with HERFD-XAS/RXES.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1021/acs.jpclett.5c01062
UR  - https://bib-pubdb1.desy.de/record/631513
ER  -