Abstract
Au nanoparticles (NPs) have been utilized in a wide range of device applications as well as catalysts for the fabrication of nanopores and nanowires, in which the performance of the associated devices and morphology of nanopores and nanowires are strongly dependent on the size, density, and configuration of the Au NPs. In this paper, the evolution of the self-assembled Au nanostructures and NPs on sapphire (0001) is systematically investigated with the variation of annealing temperature (AT) and dwelling time (DT). At the low-temperature range between 300 and 600 °C, three distinct regimes of the Au nanostructure configuration are observed, i.e., the vermiform-like Au piles, irregular Au nano-mounds, and Au islands. Subsequently, being provided with relatively high thermal energy between 700 and 900 °C, the round dome-shaped Au NPs are fabricated based on the Volmer-Weber growth model. With the increased AT, the size of the Au NPs is gradually increased due to a more favorable surface diffusion while the density is gradually decreased as a compensation. On the other hand, with the increased DT, the size and density of Au NPs decrease due to the evaporation of Au at relatively high annealing temperature at 950 °C.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-015-1200-0) contains supplementary material, which is available to authorized users.
Highlights
Metallic nanoparticles reflect highly enhanced properties with the variation of their shape, size, and density, and thereby, various devices have been fabricated based on them [1,2,3,4,5,6,7]
We investigate the evolution of the self-assembled Au nanostructures on sapphire (0001) by the control of annealing temperature (AT) and the dwelling time (DT)
The atomic force microscopy (AFM) top-view, side-view, cross-sectional line profiles and Fourier filter transform (FFT) power spectra are shown in Fig. 4 while the plots of average height (AH), average lateral diameter (LD), average density (AD), RMS roughness, and surface area ratio
Summary
Metallic nanoparticles reflect highly enhanced properties with the variation of their shape, size, and density, and thereby, various devices have been fabricated based on them [1,2,3,4,5,6,7]. The size, density, and even the shape of the nanopores can strongly depend on the size, density, and shape of the Au NPs. in the fabrication of the nanowires, the liquid-phase Au NPs act as the catalyst to absorb the target atoms in vapor phase until reaching the super-saturation. Other experiments on the metal NPs on oxide surfaces demonstrate their various properties [23], morphology [24], and evolution of Au nanostructures as a function of film thickness [25], but
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
