College of Electronics and Information, Kwangwoon University, Nowon-gu, Seoul, 139-701, South Korea.
Institute of Nanoscale Science and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA.
Nanoscale Res Lett. 2015 Dec;10(1):494. doi: 10.1186/s11671-015-1200-0. Epub 2015 Dec 24.
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.
金纳米粒子(Au NPs)在各种器件应用中得到了广泛应用,也可用作纳米孔和纳米线制造的催化剂,其中相关器件的性能和纳米孔及纳米线的形态强烈依赖于 Au NPs 的尺寸、密度和配置。在本文中,我们系统地研究了退火温度(AT)和停留时间(DT)变化时蓝宝石(0001)上自组装 Au 纳米结构和 NPs 的演变。在 300 至 600°C 的低温范围内,观察到 Au 纳米结构构型的三个不同区域,即虫状 Au 堆、不规则的 Au 纳米丘和 Au 岛。随后,在 700 至 900°C 之间提供相对较高的热能,基于 Volmer-Weber 生长模型制造出圆顶形 Au NPs。随着 AT 的增加,由于表面扩散更有利,Au NPs 的尺寸逐渐增大,而密度逐渐减小作为补偿。另一方面,随着 DT 的增加,由于在 950°C 的相对较高退火温度下 Au 的蒸发,Au NPs 的尺寸和密度减小。