Preparation of ZnO nanowires by electrochemical deposition

AbstractThis work reports the results from the synthesis of nanostructured ZnO thin films via electrochemical deposition on glass substrates coated with F doped SnO2. The influence of the deposition parameters on the properties of the obtained ZnO films was studied. The Raman spectra of the ZnO films contain the typical for ZnO vibrational bands. The scanning electron microscope micrographs demonstrate that the films consist of ZnO nanowires. Growing of ZnO in the conditions with addition of H2O2 in lower concentration and without flowing air results in larger grain formation. The ZnO layers demonstrate high diffuse reflection

ZnO:H thin films for room temperature selective NH3 sensors

International audienceZnO thin films were deposited by magnetron sputtering in Ar and Ar+H2 atmospheres. The influence of the substrate temperature, Ts, on their optical, structural and electrical properties was investigated. The optical band gap, Eopt, of the films, from transmission and reflection spectra, ranged from 3.27 to 3.31 eV, and decreased with increasing Ts. The Urbach band tail width was also calculated - its value decreased with increasing substrate temperature. XRD analyses showed an improvement of the structural properties with increasing Ts. A discussion of the influence of Ts and hydrogen on the properties is presented. The change of the sensitivity in the presence of NH3 vapour at room temperature is also presented

Sensitivity of ZnO films doped with Er, Ta and Co to NH3 at room temperature

International audienceThe sensitivity of ZnO films, undoped and doped with Er, Ta and Co, to exposure to NH3 has been studied. The films were deposited by magnetron co-sputtering of a sintered ZnO target with chips of the different doping elements on its surface. The sensitivities of the ZnO films to exposure to NH3 were measured by the quartz crystal microbalance method using the resonance frequency shift. The adsorption process was investigated over an aqueous solution of ammonia with 100 ppm concentration. The speed and the mass of sorption were calculated on the basis of the time-frequency characteristic. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim