Modification of structure and luminescence of ZnO nanopowder by the laser shock-wave treatment

The paper presents the results of the ZnO nanopowder modification investigation by means of laser shock-wave treatment. The peculiar effects of such treatment were studied at the energy density rate of similar to 10(8)-10(9) W/cm(2). The ZnO nanopowder properties were explored by using such methods as X-ray diffraction analysis (XRD), scanning electron microscopy and also by photoluminescence spectra decomposition analysis. The XRD study of ZnO nanopowder sample revealed its crystalline structure with the typical hexagonal wurtzite phase. It was also proved that laser shock-wave treatment allows to essentially changing the aggregation level of nanopowder. Additionally, the photoluminescence spectra changes of ZnO naopowders were explored both under air ambient and vacuum for the initial and laser shock-wave treated nanopowder. The decreasing intensity of green photoluminescence band and increasing intensity of the peak lambda=430 nm was observed when ambient air pressure decreases. The registered changes of visible emission are referred to the modification of defect structure, especially oxygen defects. (C) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim