Investigation On Growth And Properties Of Sb Doped ZnO Nanostructures

In recent year, Zinc oxide (ZnO) has attracted increasing interests. It is a uniquesemiconductor material with aⅡ-Ⅵwide direct band gap of 3.37eV and a relatively largeexciton binding energy of 60meV at room temperature. The larger exciton binding energymakes ZnO more competitive in obtaining efficient lasing byexcitonic emission compared toother wide-band-gap semiconductors. Because exciton-exciton scattering-induced stimulatedemissionoccurs at athresholdlowerthanthat for electron-holeplasmarecombination,ZnOisanidealmaterialforfabricatingsemiconductorlaserdevicesoperatingatroomtemperatureoreven higher. Meanwhile, ZnO nanostructores have promising potentials in extensiveapplications and are the essential building blocks for fabricating nano-optoelectronics andnano-electronicsdevice,nanosizedgassensors,transducers,andfieldemittersetc.In this thesis, aiming at the preparation difficulty in p-ZnO nanostructures materials, thefabrication and characterization of Sb doped large-scale ZnO nanorods and Sb doped ZnOnanoflowers by chemical vapor deposition method were investigated. The major researchachievementsarelistedbelow:(1) Sb doped large-scale ZnO nanorods were grown on Si (100) substrates by chemicalvapor deposition method without using of catalyst. The scanning electron microscopy(SEM)indicates the top and root diameter of the product are about 300nm and 500nm, respectively,and the length of the nanorods is about 1.5μm. Moreover, the x-ray diffraction(XRD)indicates the product has the hexagonal wurtzite ZnO structure. The energy-dispersive X-rayspectroscopy (EDS) was used to investigate the elemental composition in the Sb doped ZnOnanorods. The Sb related acceptor emission (A0X, FA, DAP, and DAP-1LO) was observed inthe photoluminescence spectra at 11K for Sb doped ZnO samples. This suggested that SbrelatedacceptorwasexistedintheZnOnanorods.(2) Sb doped ZnO nanoflowers were grown on Si (111) substrates by chemical vapordeposition method without using catalyst. The images of scanning electron microscope andthe X-ray diffraction analysis show that Sb doped ZnO nanoflowers with high crystallinequality and well optical quality were obtained. Every flower was composed of somenanopetals, which were ZnO nanorods of different growth orientation.The obtained ZnOnanorods have a uniform length of about 250nm and diameter length of about 70 nm. Theenergy-dispersive X-ray spectroscopy (EDS) was used to investigate the elementalcompositionintheSbdopedZnOnanorods. TheSbrelatedacceptoremissionswereobservedin the photoluminescence spectra at 11K for ZnO nanoflowers. This method for the preparation of Sb doped ZnO nanoflowers mayopen the way to realize the ZnO nanoflowersbasedlight-emittingdiodeandlaserdiode.