Transient X-ray Spectroscopy & Diffraction
Max Planck Research Group Michael Zürch
Transient X-ray Spectroscopy & Diffraction
Max Planck Research Group Michael Zürch

News Post
Paper on differentiating carrier and phonon dynamics at the silicon L-edge by XUV transient absorption published
Jan 28 2019

Our paper on “Differentiating Photoexcited Carrier and Phonon Dynamics in the Δ, L, and Γ Valleys of Si(100) with Transient Extreme Ultraviolet Spectroscopy” has just been published by The Journal of Physical Chemistry. In this study, we prepared carrier populations in specific valleys in the band structure of silicon by tuning our narrow-band pump pulses in on the corresponding transition energies. We observe this specific excitation does not readily 1:1 imprint on the dynamics at the absorption edge. Using a BSE-DFT model, we find that besides the carrier population itself, contributions by excited phonon modes cause a perturbation of the core-hole transition probability that additionally modifies the observed transient XUV spectra.

Comparison of the Si band structure to the XUV absorption at the Si L2,3 edge (left). Example for measured transient absorption for a specific excitation into the L-valley of silicon (right).
Original link to the journal:
https://www.nature.com/articles/s41598-019-38501-1