Synthesis and optical properties of Eu3+ and Tb3+ doped GaN nanocrystallite powders

The GaN nanocrystallite powders obtained by thermal decomposition of pure and doped gallium nitrate followed by nitridation with ammonia are investigated in this paper. The evolution of the phase composition, structure and morphology was studied. The average size of GaN nanocrystallites estimated from the broadening of XRD diffraction peaks was found to be ∼9–21 nm. The photoluminescence and cathodoluminescence properties of pure and Eu3+ and Tb3+ doped GaN nanocrystallites were measured and analyzed. A strong emission related to f–f electron transition in Eu and Tb ions has been observed. In addition, a red/yellow emission related to a recombination in the GaN nanocrystalline grains has been observed. It has been shown that this emission strongly depends on the excitation source.