The motion of dislocations in GaN-based materials was estimated quantitatively in order to determine why GaN-based devices exhibited a marked reliability in spite of extremely high dislocation densities. The dislocation velocity of GaN-based materials was calculated by estimating the activation energy of the dislocations, and comparing it with the equivalent value for GaAs. It was estimated that the dislocation mobility in GaN-related materials was lower than that in GaAs by a factor of between 10-10 and 10-16 at room temperature. Moreover, the dislocation velocity under current injection was 10 to 20 times lower than that in GaAs; assuming that the dislocations in GaN-related materials did not act as non-radiative recombination centers.

L.Sugiura: Journal of Applied Physics, 1997, 81[4], 1633-8