The effect of dewetting process on structural and optical properties of one dimensional ZnO nanostructures

One-dimensional zinc oxide (ZnO) nanostructures of different sizes were synthesized on silicon wafer substrates by controlling the substrate condition using chemical etching and a vapor-liquid-solid (VLS) process. In this work, a thin layer of gold was deposited on the silicon substrate and used as catalyst. Gold is one of the most frequently-used catalysts in the chemical vapor-deposition method. By annealing the gold-coated thin films at different temperatures, the layer was transformed into gold islands, due to the dewetting effect. To investigate the effect of the dewetting process on ZnO nanostructures, samples with various thicknesses are annealed at different temperatures. The results are compared with the uncoated and chemically-etched silicon wafers. Structural and morphological properties of the samples were analyzed using X-ray diffraction and scanning-electron microscopy. Formation of nanowires and nanorods was observed, and their sizes were dependent on the sizes of the gold islands. Photoluminescence spectra of the samples at room temperature were measured and visible emissions were observed from the synthesized nanostructures at room temperature.