Electronic and Structural Relaxation of Photoexcited WO3 Observed by Femtosecond Resonant X‑ray Emission Spectra
Yohei Uemura, Kohei Yamamoto, Yasuhiro Niwa, Thomas Buttiens, Hebatalla Elnaggar, Ru-pan Wang, Masoud Lazemi, Frank de Groot, Tetsuo Katayama, Makina Yabashi, Christopher J. Milne, Toshihiko Yokoyama
TL;DR
This study uses advanced X-ray techniques to observe how tungsten trioxide reacts to light on ultrafast timescales, revealing changes in its electronic and structural properties.
Contribution
The paper introduces the use of HERFD-XAS and RXES to study femtosecond dynamics in 5d transition metal oxides.
Findings
Photoexcitation causes a shift in the W L3 edge XAS and modulates energy levels of t2g and eg peaks.
Local structural changes around W atoms are observed within 500 fs due to polaron formation.
HERFD-XAS and RXES provide detailed insights into the early photoexcited states of WO3.
Abstract
Photoexcited states of tungsten trioxide (WO3) 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 L3 edge XAS shifts to lower energy and the energy levels of the t 2g and e g 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 2g and e g 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 WO3. This work demonstrates that the detailed dynamics of 5d elements in the femtosecond range can be addressed with HERFD-XAS/RXES.
Genes, proteins, chemicals, diseases, species, mutations and cell lines named across the full text — each resolved to its canonical identifier and authoritative record.
Click any figure to enlarge with its caption.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
Taxonomy
TopicsAdvanced Photocatalysis Techniques · Ga2O3 and related materials · Transition Metal Oxide Nanomaterials