Blue emission of ZnO nanoporous arrays membrane prepared by novel catalysis-free vertical pulsed-laser ablation

The ZnO thin films made of nanoparticles or nanoporous films were prepared by a novel vertical pulsed-laser catalyst-free ablation (VPLD) at room temperature in air. The morphologies of the annealed films at different temperatures (200, 300, 400 and 500 °C) were observed by scanning electron morphology (SEM) and their varied superficial layers were correlated to the laser powers. X-ray diffraction (XRD) patterns showed that the laser power is crucial to the formation of ZnO microcrystal structure. Photoluminescence spectra (PL) of the ZnO thin films indicated the effects of the treating temperatures and laser powers on the optical characters of the films.