Element-Specific Ultrafast Lattice Dynamics in Monolayer WSe<sub>2</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39431642.
- Also identified by DOI 10.1021/acs.nanolett.4c03611 and PMC identifier 11528438.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
We study monolayer WSe<sub>2</sub> using ultrafast electron diffraction. We introduce an approach to quantitatively extract atomic-site-specific information, providing an element-specific view of incoherent atomic vibrations following femtosecond excitation. Via differences between W and Se vibrations, we identify stages in the nonthermal evolution of the phonon population. Combined with a calculated phonon dispersion, this element specificity enables us to identify a long-lasting overpopulation of specific optical phonons and to interpret the stages as energy transfer processes between specific phonon groups. These results demonstrate the appeal of resolving element-specific vibrational information in the ultrafast time domain.