Formation of indium nitride nanostructures by atmospheric pressure plasma nitridation of molten indium

Indium nitride nanostructures have been formed by atmospheric and sub-atmospheric pressure plasma nitridation of molten indium. By nitriding the molten indium metal layer with Ar-10%N2 atmospheric pressure plasma at 435 K, micrometer-sized particles (0.7–4 μm) made up by agglomeration of nanoparticles (5–50 nm) and a variety of nanostructures (nanowires, microrods, and hollow microtubes) with various diameters (60–700 nm) have been formed, as observed by scanning electron microscopy. Transmission electron microscope observations show that these structures are composed of wurtzite type indium nitride nanocrystals (5–20 nm). By nitriding the molten indium metal with N2 sub-atmospheric pressure plasma at 673 K, hexagonal crystallites having facets (40–200 nm) have been grown to pile up. It is found that high quality indium nitride crystallites of wurtzite type single crystals can be grown at a relatively low growth temperature of 673 K, as revealed by transmission electron microscopy and Raman spectroscopy. Based on the experimental results, the main active nitrogen species for indium nitride formation are assumed to be nitrogen atoms and formation mechanisms of indium nitride nanoparticles and nanowires have been discussed.