Core-level attosecond transient absorption spectroscopy of laser-dressed solid films of Si and Zr

Abstract

We investigated experimentally as well as theoretically the ultrafast response of the wave function of the conduction band (CB) of Si and Zr to a near-infrared laser field using extreme ultraviolet (XUV) absorption 1 spectroscopy in the spectral range of 80-220 eV. The measured dynamics of the XUV transmission demonstrates that the wave function of the CB follows the electric field of the dressing laser pulse. In these terms, laser dressing was earlier mainly studied on gases. Measurements with two-femtosecond and 200-attosecond temporal steps were performed in the vicinity of the Si L 2,3 edge near 100 eV, the Si L 1 edge near 150 eV, and the Zr M 4,5 edge near 180 eV. The observed changes were dependent on the core states being excited by the XUV probe pulse. At the 2p to CB transitions of Si, the XUV transmission increased via the effect of the dressing laser pulse, while at the 2s to CB transition of Si and the 3d to CB transition of Zr, the XUV transmission decreased. Furthermore, beats between the transition from 2p 1/2 and 2p 3/2 levels of Si and from 3d 3/2 and 3d 5/2 levels of Zr were observed with 20.7 fs and 3.6 fs periods.

Improving the photocatalytic hydrogen evolution of UiO-67 by incorporating Ce4+-coordinated bipyridinedicarboxylate ligands

“…For UiO-67, after a sufficiently long delay time, the transient signal at 579 nm becomes strongly negative, indicating the occurrence of the electron transfer from ligands bpdc to the Zr metal nodes of UiO-67 during the TA spectra study. However, the corresponding peak in UiO-67-Ce becomes weak and remains positive after a sufficiently long delay time, which is consistent with the result of EPR, and the ESA decay and GSB recovery occur simultaneously [60][61][62][63]. This spectroscopic feature further confirms the existence of the energy transfer between bpdc and bpydc-Ce, inhibiting the electron transfer from bpdc to Zr in UiO-67-Ce.…”

X-ray Raman scattering: a building block for nonlinear spectroscopy

“…The impulsive, or SASE induced stimulated electronic X-ray Raman scattering process can be applied to either generate wave packets (in general electronic and nuclear wave packets), or, similar to transient absorption spectroscopy [35,36], serve as a probe process. Transient absorption spectroscopy using core levels was recently demonstrated using table-top extreme ultraviolet and soft X-ray sources in the gas phase [37,38] and in solids [39]. The control of the pulse properties, synchronization to optical pump lasers and high stability of these sources are ideal for applying a linear probe.…”

Characterization of Carrier Cooling Bottleneck in Silicon Nanoparticles by Extreme Ultraviolet (XUV) Transient Absorption Spectroscopy

“…Extreme ultraviolet (XUV) transient absorption spectroscopy makes this possible using a probe pulse in the XUV regime to measure core-level electronic transitions to characterize the occupancies and structural features of the valence and conduction bands. Promoting electrons from the silicon 2p orbital to unoccupied states creates localized core-hole excitons that impart interpretable structural information on the XUV absorption spectra. , The femtosecond resolution of the technique allows for the observation of short-lived excited carrier and phonon states …”