Solvothermal azide decomposition route to GaN nanoparticles, nanorods, and faceted crystallites

We report a straightforward, nonaqueous, solvothermal method for the production of nanoscale gallium nitride structures. Nanoparticles with spherical and rodlike morphologies are produced via in situ gallium azide precursor synthesis and decomposition in superheated toluene or THF. The solution reaction between gallium chloride and sodium azide produces an insoluble azide precursor that solvothermally decomposes to GaN at temperatures below 260 degreesC. The resulting products are poorly crystalline but thermally stable and crystallize to hexagonal GaN upon annealing at 750 degreesC. Product morphologies include nanoparticles (ca. 50 nm) and nanorods (ca. 300 nm lengths). Upon annealing, the nanoparticles coalesce into larger organized crystalline structures with hexagonal facets.