Effect of laser annealing on the properties of Ag/ZnO nanostructures

Abstract

Ag/ZnO nanostructures were synthesized using pulsed laser deposition (PLD) in open air (at atmospheric pressure). The deposition was carried out by a Nd:YAG laser, with the Ag layer composed of nanoparticles grown on SiO2 (001) substrates by the laser wavelength of 355 nm; this layer was covered by ZnO deposited by using the laser wavelength of 1064 nm. The samples were laser annealed, which led to a modification of the nanoparticles. The nanocomposites produced were characterized by TEM, UV-Vis and PL spectroscopy. The annealing procedures influence the optical properties of the Ag/ZnO nanocomposites. The laser annealing under certain parameters changes the emission behavior of the Ag/ZnO nanocomposite heterostructures. By employing localized surface plasmon resonance (LSPR), the near band edge (NBE) emission intensity of the ZnO films composed of nanoparticles was varied. An enhancement of the UV emission located at about 383 nm, commonly attributed to an excitonic transition, was registered after laser annealing with one pulse at the wavelength of 355 nm. The results obtained demonstrate that the annealing of Ag/ZnO composite nanostructures plays a key role in tuning the PL performance of a semiconductor material where an LSPR occurs.