Formation of GaAsN nanoinsertions in a GaN matrix by metal-organic chemical vapour deposition

Coherent ultrathin GaAsN insertions are formed in a GaN matrix by predeposi tion of an ultrathin GaAs layer on a GaN surface, followed by annealing in an NH3 atmosphere and overgrowth with GaN. During the overgrowth, most of t he As atoms are substituted by N, with a dense array of coherent GaAsN nano domains with lateral sizes of about 3-4 nm formed in the GaN matrix. We rep ort a green luminescence due to GaAsN insertions, surviving at high observa tion temperatures and excitation densities.