Visible to Near-IR Tunable Plasmons in Nanoporous Gold Films

This study explores the synthesis and characterization of nanoporous gold (NPG) films fabricated using a straightforward chemical etching method. Atomic force microscopy (AFM) was employed to examine the surface morphologies of NPG samples with varying film thicknesses, revealing a progressive transition from plain gold films to nanoporous structures as the thickness increases. Analysis of root-mean-square roughness (RMS) and porosity unveiled a significant dependence on film thickness, underscoring the intricate interplay between etching kinetics and film growth dynamics. Additionally, UV-Vis characterization in reflection mode showcased the tunability of plasma edge and plasmon frequency, suggesting the potential for customizing optical properties through film thickness adjustment. Overall, this research provides valuable insights into the controlled synthesis and characterization of NPG films, with implications for applications in plasmonics, sensing, and beyond.