title: A dewetting route to grow heterostructured nanoparticles based on thin film heterojunctions.
abstract: Heterostructured nanoparticles have received considerable attention for their various applications due to their unique and tunable functionalities with respect to their individual bulk constituents. However, the current wet chemical synthesis of multicomponent heterostructured nanoparticles is rather complicated. Here, we report a simple and quick method to fabricate Co-Au dumbbell arrays by dewetting Co/Au heterojunctions on a Si substrate and demonstrate that the Co-Au dumbbells vary in size from 2 to 28 nm. We further show by chemical mapping that Co bells are covered by a pseudomorphic Au wetting layer of ∼4 Å, preventing the bells from oxidation. By controlling the thickness of metal heterojunctions and the annealing time, the morphology of the Co-Au nanoparticle is found to be transformed from the dumbbell to the core shell. This facile route is demonstrated to be useful for fabricating other metal-metal and metal-oxide heterostructures and hence holds technological promise for functional applications.
authors.affiliation: Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, North Zhongshan Road 3663, Shanghai 200062, China. smhuang@phy.ecnu.edu.cn.
authors.forename: Junjie
authors.initials: J
authors.lastname: Li
authors.forename: Deqiang
authors.initials: D
authors.lastname: Yin
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Chunlin
authors.initials: C
authors.lastname: Chen
authors.forename: Sumei
authors.initials: S
authors.lastname: Huang
authors.forename: Zhongchang
authors.initials: Z
authors.lastname: Wang