Structural characterization of indium-rich nanoprecipitate in InGaN V-pits formed by annealing

InGaN layers capped with GaN were annealed at 550℃ for 1 hour. During annealing, cracks appeared and dissolved InGaN penetrated through the microcracks into the V-pits to form indium-rich nanoprecipitates. Some precipitates, in-situ annealed under nitrogen ion irradiation by MBE, were confirmed to be cubic GaN on the tops of precipitates, formed by nitriding the pre-existing Ga droplets under nitrogen ions irradiation.