Preprint Open Access
Michael Stöger-Pollach; Kristýna Bukvišová; Sabine Schwarz; Michal Kvapil; Tomáš Šamořil
Cathodoluminescence has attracted interest in scanning transmission electron microscopy
since the advent of commercial available detection systems with high efficiency, like the Gatan Vulcan or the Attolight Mönch system. In this work we discuss light emission caused by high-energy electron beams when traversing a semiconducting
specimen. We nd that it is impossible to directly interpret the spectrum of the emitted light to the inter-band transitions excited by the electron beam, because the Čerenkov effect and the related light guiding modes as well as transition radiation
is altering the spectra. Total inner re ection and subsequent interference effects are changing the spectral shape dependent on the sample shape and geometry, sample thickness, and beam energy, respectively. A detailed study on these parameters is
given using silicon and GaAs as test materials.