Formation and Characterization of Gold Nanoparticles.

摘要

Nanowires grown via the popular vapor-liquid-solid (VLS) growth mechanism require nanodroplets, most often metal, such as gold, to catalyze the growth. As the size and density of the catalytic nanoparticles are the main parameters that define the properties of the resulting nanowires, controlling the growth of these nanoparticles is of particular importance. In this study, molecular beam epitaxy (MBE) was used to grow the nanoparticles on and silicon substrates. A layer of gold was first evaporated onto the wafer and then annealed at various temperatures and for varying lengths of time. We studied the effect of the thickness of the initial gold layer, annealing temperature, and time on the size and density of the gold nanoparticles. Reflection high energy electron diffraction (RHEED) was used to observe the process in situ, and the size, density, diameter, and height of the nanoparticles were determined by atomic force microscope (AFM) and scanning electron microscope (SEM).