Metallic Nanoporous Aluminum–Magnesium Alloy for UV-Enhanced Spectroscopy

Abstract

We report the first preparation of nanoporous Al–Mg alloy films by selective dissolution of Mg from a Mg-rich alloy AlxMg1–x. We show how to tune the stoichiometry, the porosity, and the oxide contents in the final film by modulating the starting ratio between Al and Mg and the dealloying procedure. The obtained porous metal can be exploited for enhanced UV spectroscopy. In this respect, we experimentally demonstrate its efficacy in enhancing fluorescence and surface Raman scattering for excitation wavelengths of 360 and 257 nm, respectively. Finally, we numerically show the superior performance of the nanoporous Al–Mg alloy in the UV range when compared to equivalent porous gold structures. The large area to surface ratio provided by this material makes it a promising platform for a wide range of applications in UV/deep-UV plasmonics.