Nanocrystalline gallium nitride from gallium azide precursors

High quality nanoscale, phase-pure hexagonal gallium nitride (GaN) crystallites have been synthesized using the thermally induced explosion of the molecular precursor (Et₃N)Ga(N₃)₃. The method allows the control of the particle size from 2 to 24 nm. X-ray diffraction and Rietveld simulations revealed a platelet-like shape of the larger particles in contrast to the rather spherical smaller crystallites. An increasing blue-shift of the high energy luminescence with decreasing crystal size was found (up to 4.4 eV at 5 K). A preliminary analysis of the surface chemistry of has been carried out based on silylation and deuteration experiments and IR spectroscopy, indicating hydrophilic, O-H and N-H terminated particles.