Preparation of GaN\nNanocrystals with Single Ag Cores

We report on a low-temperature hybrid method for the\npreparation\nof GaN nanocrystals (NCs) with embedded single Ag cores. GaN growth\nis realized by a physical vapor deposition of Ga atoms on a SiO<sub>2</sub> substrate with colloidal Ag nanoparticles on its surface,\nassisted with an ultralow energy (50 eV) nitrogen-ion-beam bombardment\nat temperatures being significantly lower (<i>T</i> <\n350 °C) than in conventional GaN deposition techniques (e.g.,\nMOCVD, 1000°C). We call this method Low Temperature Droplet Epitaxy\n(LTDE). The low deposition temperature allows GaN nanocrystals to\nbe prepared with embedded metal–aluminum colloidal nanoparticles\nas their cores. A combination of STEM, SEM, scanning Auger microscopy,\nXPS, and AFM was applied to characterize semiconductor and metal nanoparticles.\nBy their implementation, we optimized morphology, structure, and chemical\ncomposition of these nanocrystals and, consequently, demonstrated\ntheir enhanced photoluminescent properties.