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We investigated pulsed laser deposited and laser annealed multilayer nanostructures of Ag and ZnO. The laser induced surface modification was applied for decomposition of the silver layer into nanoparticles. The morphology of the Ag nanoparticles is of critical importance in what concerns the surface plasmon resonance (SPR) properties of such multilayer structures. The combined study of the optical transmission and photoluminescence (PL) properties of the Ag/ZnO structures showed that the surface-plasmon-mediated emission is determined by both the Ag particles size and density. The study of the correlation between the structure of Ag nanoparticles array and its optical properties provides information on the threedimensional reconstruction of nanocomposites from a two-dimensional structure. The PL peak in the ultraviolet (UV) spectral region does not change substantially, while the shape and position of the visible (VIS) emission spectrum is changed and shifted towards the shorter wavelengths after the laser nanostructuring.

The experimental and theoretical investigations of the optical characteristics of laser nanostructured Ag nanoparticles (AgNPs) in ZnO medium are of particular interest for this study. The Ag-ZnO nanocomposites are fabricated by room temperature pulsed laser synthesis method. Ag nanoparticles are prepared by laser deposition and subsequent laser annealing of silver thin film. Laser annealing of silver layer is performed at second and third harmonics of the Nd:YAG laser. The morphology of AgNPs differs significantly after the UV and VIS surface modification. The morphology and optical properties of the samples are studied according to the annealing regimes. A comparative study of the measured plasmon resonance properties with the theoretical calculations of the extinction efficiency by generalized multiparticle Mie (GMM) method is carried out. The extinction spectrum is determined as a function of the nanoparticles size distribution and the surrounding ZnO medium. The electromagnetic field intensity enhancement realized in the “hot spots” of AgNPs leads to substantial enhancement of the near band-edge UV photoluminescence (PL) emission of ZnO nanostructures and attenuation of the defect-related deep-level VIS PL signal after annealing at 355 nm and 532 nm.

We report an experimental investigation on room-temperature synthesis of porous metal - semiconductor plasmonic nanocomposites by using laser deposition and annealing with nanosecond pulses. Ag/ZnO nanostructures are elaborated by using Ag-doped ZnO targets and the effects of silver concentration and laser annealing on the morphology and optical properties of the Ag/ZnO embedded nanostructures are studied. Ag-doped ZnO thin films are deposited by pulsed laser deposition on quartz substrates and subsequently laser annealed. Homemade Ag/ZnO targets with a silver doping concentration of 2, 4 and 6 at.%, prepared by ceramic technology, are exploited in the film deposition process. Then, the influence of laser irradiation on the microstructure and plasmon resonance absorption of the samples is investigated for three values of the number of laser pulses used for annealing. As the number of laser annealing pulses increases the resonance absorption is magnified. The net-like morphology of nanowires transforms to nanoparticles with increasing the silver concentration at the fixed number of ten laser annealing pulses. The composite systems show interesting plasmonic properties, which can be easily tuned by controlling the nanostructures morphology from nanowires through nanochains to nanoparticles. The experimental optical properties are in agreement with predictions of theoretical calculations showing that the extinction efficiency of AgNPs in ZnO environment peaks at about 490 nm.