Growth of zinc oxide films and nanowires by atmospheric-pressure chemical vapor deposition using zinc powder and water as source materials

Highly oriented ZnO films have been grown on c-plane sapphire substrate by atmospheric-pressure chemical vapor deposition using Zn powder and H2O as source materials. Photoluminescence intensity ratio of the green band at ∼ 2.5 eV to the near-band-edge emission at ∼ 3.2 eV (IGB/INBE) decreased with increasing the source feeding ratio of H2O to Zn (VI/II), indicating the possibility of the defect control. The absorption edge of the photoacoustic spectrum shifted towards lower energies and the resistivity decreased with increasing VI/II ratio. These tendencies are related to the incorporated H atom, the existence of which was confirmed by Raman, infrared absorption and attenuated total reflection measurements. Nanowires (NWs) of ZnO were successfully grown on the SiO2/Si(100) substrate coated with the Au nanoparticle solution or the solution for enhanced metalorganic decomposition for NiO film. The diameters of NWs grown by the former and the latter solutions changed from 50 to 250 nm and from 60 to 700 nm depending on substrate temperature and concentration of the solution, respectively. Several NWs grown on the patterned Si substrate with line-and-space pattern bridged between the mesas. Moreover, suspended NWs were grown between the Si cylindrical pillars. These results demonstrate the possibility of self-assembling nano-interconnection.