title: One-dimensional ZnO nanostructure arrays: synthesis and characterization.
abstract: One-dimensional ZnO nanostructure arrays such as nanowires, nanonails, and nanotrees, have been synthesized by oxygen assisted thermal evaporation of metallic zinc on a quartz substrate over a large area. Morphological evolution of ZnO nanostructures at different time scales and different positions of the substrates have been studied by electron microscopy. A self-catalyzed vapor-liquid-solid (VLS) process is believed to be responsible for the nucleation and subsequently a vapor-solid process is operative for further longitudinal growth. The photoluminescence spectrum showed a weak UV and a broad green emission peak at 3.25 and 2.49 eV, respectively. The latter was attributed to the presence of zinc interstitial defects. Electrical resistivity as a function of temperature showed activated mechanisms to be present. The electrical response of the ZnO nanonail arrays to different gases (CO, NO2, and H2S) indicated that there could be possible application as gas sensors for this material.
authors.affiliation: DST Unit on Nano Science & Department of Materials Science, Indian Association for the Cultivation of Science, Kolkata 700 032, India.
authors.forename: Soumitra
authors.initials: S
authors.lastname: Kar
authors.forename: Bhola Nath
authors.initials: BN
authors.lastname: Pal
authors.forename: Subhadra
authors.initials: S
authors.lastname: Chaudhuri
authors.forename: Dipankar
authors.initials: D
authors.lastname: Chakravorty