Catalyst-free synthesis of ZnO nanowall networks on Si₃N ₄/Si substrates by metalorganic chemical vapor deposition

ZnO nanowall networks were synthesized on Si₃N₄/Si (100) substrates at low growth temperature of 350°C by metalorganic chemical vapor deposition (MOCVD) without any help of metal catalysts. Depending on MOCVD-growth conditions, a large number of nanowalls with extremely small wall thicknesses below 10 nm are formed into nanowalls with a thickness of about 20 nm, resulting in the formation of two-dimensional nanowall networks. The ZnO nanowall networks were found to have a preferred c-axis orientation with a hexagonal structure in synchrotron x-ray scattering experiments. Room-temperature hydrogen incorporation into ZnO nanowall networks has been observed in photoluminescence measurements.