Photoelectron Energy Loss Spectroscopy (XPS-PEELS) has a double interest, since it gives access to both chemical composition and electronic properties of a solid. The dielectric function of the solid surface (depth ~ 5 nm) over a large energy range (0-50 eV) can be retrieved from the energy distribution of inelastically scattered photoelectrons that excite volume and surface plasmons, as observed in XPS experiments.
Energy loss spectrum of C1s photoelectrons - for a PLD amorphous carbon film terminated by a grafted alkyl monolayer with ester end-groups (3.7×1014 cm-2). Volume and surface losses were measured as a function of the off-normal emission angle: α = 0, 45, 55, 65, 75 degrees.
A first version of the PEELS algorithm has been tested using model materials (amorphous silicon, polycrystalline diamond), along with amorphous carbon films, before and after covalent immobilization of molecular monolayers. Recently, a Fourier transform method has been developed to extend this method to metal surfaces.
- Derivation of dielectric function and inelastic mean free path from photoelectron energy-loss spectra of amorphous carbon surfaces, D. DAVID, C. GODET, Applied Surface Science 387, 1125-1139 (2016).
- Photoelectron Energy Loss in Al(002) Revisited: Retrieval of the Single Plasmon Loss Energy Distribution by a Fourier Transform Method, V.M. SANTANA, D. DAVID, J.S. de ALMEIDA, C. GODET, Brazilian Journal of Physics, 48, 215-226 (2018).
- Depth distribution of noble gas atoms implanted in Al matrix : a photoelectron energy loss spectroscopy study, C. GODET, V.M. SANTANA, D. DAVID, Thin Solid Films 659, 70-80 (2018).