Optical behaviours of two dimensional Au nanoparticle arrays within porous anodic alumina

The optical responses of Au nanoparticle arrays dispersed within porous anodic alumina (PAA) have been investigated. The 2D Au/PAA structures were well preparing by immersing various pore sizes of PAAs into the mixing solution of HAuCl4, cetyl-trimethyl ammonium bromide, and NaBH4 under Au phase transfer processes. With the dispersion of Au nanoparticles in those nanopores in PAA, the intensity of photoluminescence light and cathodoluminescence light spectra largely decreases. The dissipated emission could be interpreted by the partly sealing of the light emission oxygen defect centers in PAA with the dispersion of Au nanoparticles. The major absorption comes from the interface plasmon resonance of Au nanoparticles surrounding with PAAs. The excited Au nanoparticles act as a Bragg grating for wave propagation scattering into the alumina matrix.