Tunable surface plasmon resonance of Al-Cu bimetallic nanoparticles thin films induced by pulsed-laser.

• Al-Cu bimetallic nanoparticles (NPs) thin films were fabricated by Nd:YAG fiber-pulsed laser irradiation. • The tunability of both localized surface plasmon resonance (LSPR) wavelength and intensity were realized. • SERS performance and FDTD simulation were applied to demonstration the potential application of tunable LSPR properties. Al-Cu bimetallic nanoparticles (NPs) thin film was fabricated by Nd:YAG fiber pulsed-laser irradiation of Al/Cu bilayers at ambient conditions. The effects of laser irradiation on the morphology, structure, composition and optical properties of the samples were investigated. The tunability of both localized surface plasmon resonance (LSPR) wavelength and intensity were realized by varying the pulse shot or relative thickness of Al/Cu bilayers. The SEM analysis with EDS results further revealed that the obtained particles consisted of a mean diameter of 36–80 nm bimetallic NPs system, being dependent on the Cu proportion. In addition, Surface-enhanced Raman spectroscopy (SERS) measurement and corresponding finite-difference time-domain (FDTD) simulation of before and after laser irradiation samples were discussed to verify the LSPR properties. [ABSTRACT FROM AUTHOR]