Self-assembly of Au nano-islands with tuneable organized disorder for highly sensitive SERS

Zelio Fusco, Renheng Bo, Yuling Wang, Nunzio Motta, Hongjun Chen*, Antonio Tricoli

*Corresponding author for this work

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Aggregates of disordered metallic nano-clusters exhibiting long-range organized fractal properties are amongst the most efficient scattering enhancers, and they are promising as high performance surface-enhanced Raman scattering (SERS) substrates. However, the low reproducibility of the disordered structures hinders the engineering and optimization of well-defined scalable architectures for SERS. Here, a thermophoretically driven Au aerosol deposition process is used for the self-assembly of thin films consisting of plasmonic nano-islands (NIs) with a controllable and highly reproducible degree of disorder. The intrinsic Brownian motion of the aerosol deposition process results in long-range periodicity with self-similar properties and stochastically distributed hot-spots, providing a facile means for the reliable fabrication of crystalline Au substrates with uniform disorder over large-surfaces. These morphological features result in the generation of a high density of hot-spots, benefitting their application as SERS substrates. NI substrates with an optimal uniform disorder demonstrate a SERS enhancement factor (EF) of 107-108 with nanomolar concentrations of Rhodamin-6G. These findings provide new insights into the investigation of light scattering with disordered structures, paving the way toward low-cost scalable self-assembly optoelectronic materials with applications ranging from ultrasensitive spectroscopy to random lasing and photonic devices.

Original languageEnglish
Pages (from-to)6308-6316
Number of pages9
JournalJournal of Materials Chemistry C
Volume7
Issue number21
DOIs
Publication statusPublished - 7 Jun 2019

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