Growth and annealing of GaInAsN: density-functional calculations on the reactions of surface and bulk structures

The annealing behaviour of bulk structures formed by deposition is investigated using energetic data calculated by the density-functional supercell method. Ga4−mInmN centres are the most stable arrangements in the bulk. During the annealing process nitrogen atoms move from the Ga4N centres to isolated indium atoms or pairs of indium atoms by N/As exchange. This is supported by the calculated blueshift of the band-gap during the exchange process, which agrees well with the experimental observed blueshift.