title: Evolution of Self-Assembled Au NPs by Controlling Annealing Temperature and Dwelling Time on Sapphire (0001).
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.
authors.affiliation: College of Electronics and Information, Kwangwoon University, Nowon-gu, Seoul, 139-701, South Korea. jihoonlee@kw.ac.kr.|Institute of Nanoscale Science and Engineering, University of Arkansas, Fayetteville, AR, 72701, USA. jihoonlee@kw.ac.kr.
authors.forename: Jihoon
authors.initials: J
authors.lastname: Lee
authors.affiliation: College of Electronics and Information, Kwangwoon University, Nowon-gu, Seoul, 139-701, South Korea. ppcpurans@gmail.com.
authors.forename: Puran
authors.initials: P
authors.lastname: Pandey
authors.affiliation: College of Electronics and Information, Kwangwoon University, Nowon-gu, Seoul, 139-701, South Korea. maosui001@gmail.com.
authors.forename: Mao
authors.initials: M
authors.lastname: Sui
authors.affiliation: College of Electronics and Information, Kwangwoon University, Nowon-gu, Seoul, 139-701, South Korea. mingyuli.oliver@gmail.com.
authors.forename: Ming-Yu
authors.initials: MY
authors.lastname: Li
authors.affiliation: College of Electronics and Information, Kwangwoon University, Nowon-gu, Seoul, 139-701, South Korea. kwuzqz@gmail.com.
authors.forename: Quanzhen
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: College of Electronics and Information, Kwangwoon University, Nowon-gu, Seoul, 139-701, South Korea. kunwarankees23@gmail.com.
authors.forename: Sundar
authors.initials: S
authors.lastname: Kunwar
keywords: Annealing temperature; Au nanoparticle; Au piles; Dwelling time; Nano-mounds