Fabrication of nanoribbons by dielectrophoresis assisted cold welding of gold nanoparticles on mica substrate

Song-Hyun Cha,Youmie Park,Se-Hyeon Kang,Seonho Cho,Eun-Young Ahn,You Jeong Lee,Jae-Hyun Kim

doi:10.1038/s41598-019-40248-8

Song-Hyun Cha, Youmie Park + Show 5 more

Open Access

https://doi.org/10.1038/s41598-019-40248-8

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Journal: Scientific Reports	Publication Date: Mar 6, 2019
Citations: 15	License type: open-access

Affiliation: Seoul National University, Inje University

Abstract

Using alternating current electric fields, nanoribbons are fabricated from an aqueous suspension of gold nanoparticles (AuNPs) on mica substrate without resorting to further chemical functionalization of AuNPs. The potential and kinetic energies of AuNPs subjected to attractive forces from a mica substrate provide sufficient energy to pass the diffusion barrier of the gold atoms, which eventually leads to cold welding. A dielectrophoresis force exerted on polarizable particles in a non-uniform electric field contributes to the directed growth of the cold welding that occurs by adjusting the lattice structures of AuNPs. Depending on the concentration of the AuNP suspension, the frequency of the electric field, and the geometry of electrodes, various morphologies of nanoribbons are fabricated. It turns out that the welded region is nearly perfect to provide the same crystal orientation and strength as the rest of the nanostructures, which can be extensively utilized in the fabrication of various nanostructures.

Highlights

Various nanostructures such as nanoparticles, nanowires, nanoplates, nanoribbons, and so on are attracting increasing attention since they are considered as the main building blocks of nanostructures, which are intended by applying novel bottom-up fabrication methods based on self-assembly[1]
It is known that the aggregation of aqueous suspension of gold nanoparticles (AuNPs) occurs during the sample preparation for Atomic Force Microscopy (AFM) measurement, which turns out that the aggregation is originated from a cold welding phenomenon[16]
The high quality in the cold welding of suspended AuNPs on mica substrate is attributed to the following ingredients: ‘oriented-attachment’ naturally activated in the AuNP suspension on mica substrate, ‘enhanced atomic diffusion’ from the high surface to volume ratio of AuNPs, and ‘surface relaxation and reconstruction’[16]

Summary

Introduction

Various nanostructures such as nanoparticles, nanowires, nanoplates, nanoribbons, and so on are attracting increasing attention since they are considered as the main building blocks of nanostructures, which are intended by applying novel bottom-up fabrication methods based on self-assembly[1]. We discuss about DEP-assisted cold welding of AuNPs on mica substrate through the observation of High Resolution - Transmission Electron Microscope (HR-TEM), AFM, and Field Emission - Scattering Electron Microscope (FE-SEM) images.

Results

Conclusion