Accuracy of the calculated unoccupied states in GaN phases as tested by high-resolution electron energy-loss spectroscopy

The electronic structures of cubic and hexagonal phases of GaN have been investigated by high-resolution electron energy-loss spectroscopy in a monochromated transmission electron microscope. Both the Ga-L2,3 and N K-edges were measured. The data are compared to the latest versions of two different calculation schemes: band structure and multiple-scattering calculations. We have found that both methods are capable of giving results that can be …