Ultrafast Electron Diffraction and Structural Characterization During Phase Transitions

The SLAC group has performed ultrafast electron diffraction studies to study the sub-ps photoinduced lattice dynamics in MoSe2in the electron-hole plasma density regime. The USC group used nonadiabatic quantum molecular dynamics (NAQMD) simulations to identify light-induced phonon softening as the cause for this efficient carrier-lattice energy transfer.

Ultrafast electron diffraction enables femto-second time-resolved structural characterization of materials. Here, we observe an anisotropic structural response of bilayer MoSe2 crystals due to photoexcitation by a 400 nm optical pulse.


  1. Ultrafast non-radiative dynamics of atomically thin MoSe2. M.-F. Lin, V. Kochat, A. Krishnamoorthy, L. Bassman, C. Weninger, Q. Zheng, X. Zhang, A. Apte, C. Tiwary, R. Li, R. Kalia, P. Ajayan, A. Nakano, P. Vashishta, F. Shimojo, X. Wang, D. M. Fritz, U. Bergman. Submitted

PIs involved in the research

  • Uwe Bergmann, David Fritz (SLAC)
  • Pulickel Ajayan (Rice)
  • Aiichiro Nakano, Priya Vashishta (USC)

Published on May 30th, 2017

Last updated on January 28th, 2020