Dynamics of Photoelectrons and Structural Changes of Tungsten Trioxide Observed by Femtosecond Transient XAFS

The dynamics of the local electronic and geometric structures of WO3 following photoexcitation were studied by femtosecond time-resolved X-ray absorption fine structure (XAFS) spectroscopy using an X-ray free electron laser (XFEL). We found that the electronic state was the first to change followed by the local structure, which was affected within 200 ps of photoexcitation.