Spectrometer-free electron probe of ultrafast thermal dynamics in optically excited samples

Cutting edge electron microscopes allow to probe the optical excitations in nanostructures with subangstrom spatial and femtosecond temporal resolution. In this study we discuss the prospects of probing the ultrafast out-of-equilibrium dynamics of plasmonic excitations in graphene and graphite samples. We show that, the plasmon excitation dynamics in nanostructured graphene and graphite can be traced through energy integrated and momentum resolved spectra of inelastically scattered electrons in contrast to more traditional energy-resolved spectroscopy approach, where highly-monochromatized electron beams and electron spectrometers with sufficient energy resolutions are essential. (C) 2021 The Author(s)