Enhancement of ZnO photoluminescence by laser nanostructuring of Ag underlayer

Results are presented on the synthesis and characterization of nanocomposite Ag/ZnO heterostructures on fused quartz substrates. The experiments were performed by pulsed laser deposition (PLD) using a third harmonic Nd:YAG laser in a vacuum chamber. The ablation of a rotated Ag target was followed by laser modification of the deposited layer and subsequent deposition of ZnO. The process factors, such as the silver film thickness and the post-deposition annealing procedures, were varied in view of controlling the diameter and size distribution of the Ag nanoparticles. The annealing regimes were modified by varying the laser irradiation energy on the Ag layers. The effect on the Ag/ZnO properties is discussed. It is demonstrated that the photoluminescence intensity of ZnO nanolayers is significantly enhanced by plasmon absorption in the Ag nanoparticles and a shift to the lower wavelengths.