Organic vapor sensor using photoluminescence of laser ablated gold nanoparticles on porous silicon

Gold nanoparticles (AuNPs) were prepared by laser ablation technique of gold target submerged in double distilled deionized water (DDDW) at room temperature. AuNPs are incorporated into porous silicon (PS) that was prepared using the electrochemical etching technique. In this study, the influence of gold colloids on PS characteristics has been investigated. The variation of the surface roughness and morphology after noble metal modification was revealed by Atomic Force Microscopy (AFM), while, Fourier Transform Infrared (FTIR) characterization techniques proved the oxidation of porous silicon substrate leading to the passivation of the surface states. It was also observed that the reflectivity was decreased due to the deposition process depending on the size and the quantity of gold colloid solution. These are attributed to metal nanoparticles (MNPs) with narrow particle-size distribution uniformly coated on the surface, thus, the substrate efficiency is strictly related to their dispersion, which could yield to local surface Plasmon (LSP).The photoluminescence (PL) spectroscopy revealed that the intensity is strongly depend on AuNPs deposition and effected by organic vapor after deposition on PS.