Direct Synthesis, Growth Mechanism, and Optical Properties of 3D AlN Nanostructures with Urchin Shapes

Aluminum nitride (AlN) nanostructures have shown novel physical and chemical properties that are essential for technological applications. We report a vapor-solid growth of novel three-dimensional (3D) AlN urchin-like nanostructure in DC arc plasma via the direct reaction between Al vapor and N-2 gas without any catalyst or template. The as-prepared 3D AlN nanostructures which have urchin-like shapes consist of numerous microdaggers with sharp tips and lengths of up to several micrometers and widths of 0.5-2 mu m. A growth mechanism of AlN nanostructures with urchin shapes was suggested and explained in detail. The optical properties of the AIN nanostructures with urchin shapes were also studied with photoluminescence spectrum, which reveals a broad emission, suggesting potential applications in electronic and optoclectronic nanodevices.