Luminescent properties of ZnO nanoparticles doped with W obtained in plasma discharge in liquid under ultrasonic cavitation

ZnO:W luminescent material was prepared and characterized. We compare nano-sized and bulk material composition and luminescence. Nanoparticles were prepared by a novel acoustoplasma technique (plasma discharge in a liquid at an intensive ultrasonic field above the cavitation threshold). Bulk ZnO:W was prepared by classical annealing way from the mixture of ZnO powder and H2WO4. Under excitation with a pulsed electron beam, the ZnO:W nanoparticles demonstrated very low luminescence efficiency while the bulk sample produced intensive green cathodoluminescence. The most intensive green luminescence was observed after annealing of the sample in air, which excludes a well-known mechanism involving anion vacancies. Probably, tungsten impurity tunes excitonic luminescence towards longer wavelengths, but this point requires further investigations for verification.