Fabrication of Au network by low-degree solid state dewetting: Continuous plasmon resonance over visible to infrared region

Solid state dewetting (SSD) of thin-film can trigger morphology evolution from continuous film to isolated nanostructures over percolation threshold. However, the Au thin-film fabricated by low-degree SSD, namely Au network nanostructures, showed a wider plasmon absorption over visible and mid-infrared region as compared to the fully-developed nanoparticles. The optical properties of Au networks is systematically investigated by assistant of finite difference-time domain (FDTD) analysis in terms of E-field distribution and extinction efficiency. It is shown that the semi-manufactured irregular nanostructure possess strong plasmon resonance even at the wavelength up to 1900 nm. The monochromic plasmon responds of corresponding low-developed and high-developed samples are examined by surface enhanced Raman spectroscopy with 532 nm laser excitation. And for polychromic light, solar simulator was employed to evaluate the photocurrent performance of TiOx/Au network hybrid film. The results suggest the Au network have large potentials to be utilized under polychromic LSPR excitation scenes such as solar irradiation to improve the photoelectric properties. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.