Scanning Kelvin probe microscopy and non-contact atomic force microscopy were used to characterize dislocations in Ga0.65Al0.35N/GaN heterostructures. The surface-potential variations around dislocations in the heterostructures were observed to be equal to 0.1 to 0.2V, with full-widths at half-maximum of 100 to 200nm. The dislocations (at densities of some 109/cm2) were found to be negatively charged.

Scanning Kelvin Probe Microscopy Characterization of Dislocations in III-Nitrides Grown by Metalorganic Chemical Vapour Deposition. G.Koley, M.G.Spencer: Applied Physics Letters, 2001, 78[19], 2873-5