Optical characterization of GaN by N+ implantation into GaAs at elevated temperature -: art. no. 261915

Both hexagonal wurtzite and cubic zinc blend GaN phases were synthesized in GaAs by 50 keV N+ implantation at 400 degrees C and subsequent annealing at 900 degrees C for 15 min in N-2 ambient. The crystallographic structural and Raman scattering studies revealed that GaN phases were grown for fluence above 2 x 10(17) cm(-2). Temperature-dependent photoluminescence study showed a sharp direct band-to-band transition peak similar to 3.32 eV at temperature <= 200 K. The intermediate band-gap value, with respect to similar to 3.4 eV for hexagonal and similar to 3.27 eV for cubic phases of GaN, is indicative of the formation of mixed hexagonal and cubic phases. (c) 2005 American Institute of Physics.