Synthesis of GaN quantum dots by ion implantation in dielectrics

GaN nanocrystals (in the wurtzite phase) were synthesized by sequential imp lantation of Ga and N ions into either crystalline (quartz, sapphire) or am orphous (silica) dielectrics, followed by annealing of the samples in flowi ng NH3 gas at 900 degreesC. GaN was formed by reaction of implanted Ga with NH3 combustion products and/or via conversion of Ga oxide/oxynitrides. A b lueshift of the near-band-edge photoluminescence (quantum-confinement effec t) was observed for GaN nanocrystals with size less than or equal to2-3 nm, present in all the substrates. (C) 2001 American Institute of Physics.