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

Abstract 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.