The recent advances in transmission electron microscopes (TEM) bring access to electron probes of one angstrom within energy resolutions of ~ 100 meV (even few tens of meV) even working at low acceleration voltages (60-80 kV) [1]. These performances offer new possibilities for probing the optical, dielectric and electronic properties of nanomaterials with unprecedented spatial information, as well as for studying the atomic configuration of nanostructures [1-3]. In this contribution, I will present a selection of recent works involving all these matters. These works will concern the study of the atomic structure & configuration of 2D atomically thin materials (including dichalcogeneides in pristine and hybrid forms) as well as the opto electronic properties studies carried out via EELS measurements, see Fig. 1 [4-8]. These works will illustrate the excellent capabilities offered by the use of a Cs probe corrected STEM, combined with the use of a monochromator, to study these properties within a very good spatial resolution.

The recent advances in transmission electron microscopes (TEM) bring access to electron probes of one angstrom within energy resolutions of ~ 100 meV (even few tens of meV) even working at low acceleration voltages (60-80 kV) [1]. These performances offer new possibilities for probing the optical, dielectric and electronic properties of nanomaterials with unprecedented spatial information, as well as for studying the atomic configuration of nanostructures [1-3]. In this contribution, I will present a selection of recent works involving all these matters. These works will concern the study of the atomic structure & configuration of 2D atomically thin materials (including dichalcogeneides in pristine and hybrid forms) as well as the opto electronic properties studies carried out via EELS measurements, see Fig. 1 [4-8]. These works will illustrate the excellent capabilities offered by the use of a Cs probe corrected STEM, combined with the use of a monochromator, to study these properties within a very good spatial resolution.