Configuration, Dimension and Density Control of 3-D Gold Nanostructures on Various Type-B GaAs Surfaces by the Systematic Variation of Annealing Temperature, Annealing Duration and Deposition Amount

Metallic nanoparticles have received extensive research attention due to their potential to be utilized in catalytic, electronic and optical applications. Tunable feature of quantum effect related to the configuration, dimension as well as the density of nanoparticles makes them appropriate building blocks for their applications at the nano-scale. In this paper, we systematically investigate the fabrication of self-assembled Au nanoparticles on high-index type-B GaAs (n11), where n is 9, 8, 4, and 2. By means of varying annealing temperature, Au deposition amount and annealing duration, the evolution of Au nanoparticles in terms of the average height, lateral diameter and average density is systematically studied. We observe that the variation of annealing temperature leads to an abrupt configuration evolution from the wiggly Au nanostructures to the round-dome shaped nanoparticles due to the limited and/or enhanced surface diffusion at various temperatures. Meanwhile, the variation of deposition amount leads to a wide range of dimensions of Au nanoparticles as a result of the size increase and the corresponding density decrease. Furthermore, based on the annealing duration control, the size of Au nanoparticles tends to be gradually increased owing to the Ostwald-ripening. Meanwhile, the effect of surface index on the size and density is also witnessed. The results are systematically analyzed by using the atomic force microscope images, energy-dispersive X-ray spectroscopy spectra and maps, Fourier filter transforms power spectra, cross-sectional line-profiles and size and density plots.