Capturing electrons in motion at the nanometer, femtosecond scale

The flow of electrons in materials drives much of technology today. The ability to directly image these charge dynamics promises to deepen our understanding of the fundamental processes involved and impact future technology. Today, I will discuss our recent work in time resolved photoemission electron microscopy, which allows making movies of electron dynamics in materials with nanometer, femtosecond scale resolution. We will discuss the imaging the motion of electrons across semiconductor heterojunctions [1], separating photoexcited electrons on an ultrafast timescale [2], and probing the ultrafast dynamics of carriers at nanoscale trap sites in perovskites. Time permitting, I will talk about the unique scientific environment on the island resort of Okinawa, where these experiments were done.

References:

[1] MKL Man et al. 2017, Nature Nanotech, 12, 36 
[2] E. L. Wong et al. 2018, Science Adv. 4, eaat9722