Group-III nitride nanoparticles - synthesis and photoluminescence studies

GaN nanoparticles were synthesized wet chemically from triethylgallium and ammonia via the trimeric precursor [Et₂GaNH₂]₃. The as-synthesized particles were smaller than 5 nm and comprised, a mixture of cubic, hexagonal and possibly amorphous GaN, exhibiting band edge related luminescence. Upon annealing in NH₃ in the presence of indium, the particle size increased to 30 nm and all particles possessed hexagonal crystal symmetry. Only deep level related luminescence was recorded from the annealed particles at room temperature, most likely resulting from residual carbon impurities in the crystal. No improvement in the structural quality was observed when the samples were annealed in the absence of indium.