Probing nanoscale dynamics using ultrafast electron diffraction

Nanoscale materials exhibit remarkable optical, electronic, and thermal properties due to quantum confinement and surface effects, offering vast potential in optoelectronic applications. Their device performances are set by the interplay of spin, charge, orbital, and lattice dynamics, and an in-depth understanding of these dynamical processes would be essential to realize their full application potentials. Utilizing ultrafast electron diffraction (UED) with pump-probe techniques provides a unique window into unraveling these complex processes. In this talk, I will present several UED-based projects investigating structural dynamics in several nanomaterial systems. These  include probing nanoscale thermal transport across the GaAs/AlGaAs interface [1], understanding the role of Auger process in carrier relaxation within semiconductor quantum dots [2], and studying the photoinduced shortening of metallic bond in two-dimensional layered material of 1T’-ReS₂ [3]. I will particularly focus on the ramification of these dynamics on the structural dynamics, which can be directly probed with UED in real time on the relevant timescales.

References

1. Matthew Gorfien, et al., Struct. Dynamics 7, 025101 (2020)
2. L. Yue, et al., Nano Lett. 23 (7), 2578–2585 (2023)
3. J. Li, et al., Appl. Phys. Lett. 124, 171905 (2024)