%0 Generic
%A Ryklin, Daniel
%C Heidelberg
%D 2024
%F heidok:35203
%R 10.11588/heidok.00035203
%T bsEELS:A new method for Electron Energy Loss Spectroscopy on backscattered electrons inside a Scanning Electron Microscope
%U https://archiv.ub.uni-heidelberg.de/volltextserver/35203/
%X In this doctoral thesis I introduce the novel approach of performing electron energy loss spectroscopy (EELS) on backscattered electrons (BSE) inside a scanning  electron microscope (SEM), which we call backscattered EELS (bsEELS). EEL spectra from BSE are acquired at ultra-low primary electron energy down to 10 eV with 1 nm spatial resolution. This allows large area spectroscopic imaging  studies on bulk materials with surface signal information confined to few nanometers, thereby complimenting and bridging the limitations of established (scanning)  transmission electron microscopy ((S)TEM-) EELS and high resolution / reflective (HR/R-) EELS methods. The experimental data from a variety of inorganic, carbon, and organic materials prove that bsEELS is in particular suited to access the low-loss energy regime containing primarily surface plasmon and conduction band excitations. Current limitations concerning the energy resolution caused  by energy spreading on the bent beam path towards a retarding grid potential spectrometer are discussed in detail. A forward convolution model is established  to interpret the experimental data with respect to spectroscopic reference measurements (UV-Vis, TEM EELS, HREELS). Finally, improvements of the current experimental design are discussed to access high-resolution spectral information with bsEELS in the future.