Optical constants of organic insulators in the UV range extracted from reflection electron energy loss spectra

Reflection electron energy loss spectroscopy (REELS) spectra were measured for seven insulating organic compounds (DNA, Irganox 1010, Kapton, polyethylene [PE], poly(methyl methacrylate) [PMMA], polystyrene [PS] and polytetrafluoroethylene [PTFE]). Optical constants band gaps extracted from the REELS after elimination of multiple scattering via a deconvolution fitting normalised single to Drude Drude–Lindhard model dielectric functions, constrained by Kramers–Kronig sum f ‐sum rules. Satisfactory agreement is found those optical which literature data exists. For PTFE, observed features in correspond its electronic structure.