Determination of the diffusion lengths of Ga adatoms using GaN stripe profiling

We present a method for determining the diffusion lengths of Ga adatoms on GaN by combining profiling of the tops of GaN stripes obtained by selective area MOCVD and a diffusion growth model. We deduce very high values of the diffusion lengths on tops of -oriented stripes at 1040 °C which range from 6 μm under nitrogen-rich to 24 μm under hydrogen-rich atmosphere in the reactor. The obtained results show in particular that Ga-catalyzed growth of GaN nanostructures and nanowires should not be limited by Ga influx and thus the exceptional growth rate is anticipated in such cases.