The dielectric theory of HREELS, a short survey

The dielectric theory of high-resolution electron-energy-loss spectroscopy (HREELS) is now more than thirty years old [A.A. Lucas and M. Sunjic, Phys. Rev. Lett. 26, 229 (1971)]. Since the very begining , this theory revealed to be a great sucess, for it provided immediately a quantitative description of energy-loss spectra obtained in specular reflection by newly-developed surface spectrometers [H. Ibach, Phys. Rev. Lett 24, 1416 (1971)]. First designed to deal with simple crystalline materials, the Lucas-Sunjic theory has been progressively adapted to more complex systems. A brief, comprehensive presentation of the theory is given together with a short description of its lastest developments. The sucess of the theory is illustrated with recent examples of HREELS experiments performed on GaAs/AlGaAs heterostructures, C60 fullerenes films, and carbon nanosystems.