Off-axis electron holography in a transmission electron microscope was used to examine the charge on threading edge dislocations in n-GaN (00•1). It was shown that the crystal inner potential was reduced within 10nm of the dislocation consistent with a negatively charged core. The results could be explained by a simple unscreened potential due to a core charge of about 4 x 107e/cm. The application of the method to other types of dislocation was also considered.

Electron Holography Studies of the Charge on Dislocations in GaN. D.Cherns, C.G.Jiao: Physical Review Letters, 2001, 87[20], 205504 (4pp)