Horizontal zinc oxide nanomaterials growth and their application for surface enhanced raman scattering

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Nanonecklace (NNs) or nanochains (NCs), aligned nanoparticles (NPs) in straight or curled shape, have been demonstrated using metals, silicon, silicides, and oxides. The most common methods for fabricating NCs structure are solution process, which typically can not provide good control of their alignment and positions. Chemical vapor deposition (CVD) has been used to achieve one-dimensional nanostructures, including both single walled carbon nanotubes (SWNT) and NWs, with relatively good structural control. For example, sapphire substrates have been used to align SWNT or zinc oxide NWs. In this thesis, a novel ZnO NNs structure growth along ZnO c-axis on r-plane sapphire substrates with alignment along [211] sapphire direction is presented. Also, the application of NNs into surface enhanced Raman scattering (SERS) is showed. The rationale behind the SERS application is that metal coated ZnO NPs with nanosized spacing in a ZnO NN have "hot-spots" with significantly enhanced magnetic field that enhances the surface plasmons resonances and Raman signals. It is hoped that the ZnO NN can not only provide a viable solution for the SERS application but also be applied in electronics fields.