Fabrication of single-crystalline plasmonic nanostructures on transparent and flexible amorphous substrates

Tomohiro Mori,Tomohiro Mori,Kenzo Yamaguchi,Yasuhiro Tanaka,Takeshi Mori,Yoshifumi Suzaki

doi:10.1038/srep42859

Tomohiro Mori, Tomohiro Mori + Show 4 more

Open Access

https://doi.org/10.1038/srep42859

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Abstract

A new experimental technique is developed for producing a high-performance single-crystalline Ag nanostructure on transparent and flexible amorphous substrates for use in plasmonic sensors and circuit components. This technique is based on the epitaxial growth of Ag on a (001)-oriented single-crystalline NaCl substrate, which is subsequently dissolved in ultrapure water to allow the Ag film to be transferred onto a wide range of different substrates. Focused ion beam milling is then used to create an Ag nanoarray structure consisting of 200 cuboid nanoparticles with a side length of 160 nm and sharp, precise edges. This array exhibits a strong signal and a sharp peak in plasmonic properties and Raman intensity when compared with a polycrystalline Ag nanoarray.

Highlights

Provide high transmissivity, its amorphous nature prevents directly obtaining a large single-crystalline area
The NaCl substrate was dissolved in ultrapure water at room temperature, as shown Fig. 1(b)
The single-crystalline Ag film floated on the ultrapure water, allowing it to be transferred to a 1-mm-thick SiO2 substrate or 100-μm-thick flexible polyethylene terephthalate (PET) film at the air-water interface (Fig. 1(c))

Summary

Introduction

Provide high transmissivity, its amorphous nature prevents directly obtaining a large single-crystalline area. It is very difficult to produce a single-crystalline metallic film on a transparent and flexible polymer. If plasmonic components could be created on transparent, flexible, stretchable, nonplanar, and biocompatible substrates, rather than conventional rigid substrates, potentially providing circuit components new functionalities for next-generation optical devices. We propose using ultrapure water to remove the NaCl substrate, thereby allowing the Ag film to be transferred onto SiO2 or flexible polyethylene terephthalate (PET) film. As this eliminates the need for solvents or mechanical stripping, there should be no damage to the Ag film surface. The optical properties of the resulting single-crystalline Ag films and nanostructures are investigated and compared to a conventional polycrystalline films and nanostructures

Methods

Results

Conclusion