First-principles calculations of electron energy loss spectra for bulk GaN were compared with experimental spectra acquired with a scanning tunneling electron microscope offering ultra-high-energy resolution in low-loss energy spectroscopy. The theoretical bulk low-loss electron energy loss spectra, in the Eg to 10eV range, were in good agreement with experimental data. Spatially resolved spectra from dislocated regions were distinct from bulk spectra. The main effects were confined to energy losses lying above the band edge. The calculated spectra for low-energy dislocations showed that difficulties remained in understanding the spectra of threading dislocations in GaN.

Calculated and Experimental Low-Loss Electron Energy Loss Spectra of Dislocations in Diamond and GaN. R.Jones, C.J.Fall, A.Gutiérrez-Sosa, U.Bangert, M.I.Heggie, A.T.Blumenau, T.Frauenheim, P.R.Briddon: Journal of Physics - Condensed Matter, 2002, 14[48], 12793-800