Zero-bias anomaly in one-dimensional ultrathin metallic nanowires AIP Advances 2, 032143 (2012) Influence of electron scatterings on thermoelectric effect ZnO nanowires were grown between two Au electrodes on an Al 2 O 3 -deposited Si wafer. Photoresponse, photoresponse spectrum, and current-voltage (I -V) studies were performed for the investigation into photoconduction mechanism in these nanowires. The photoresponse of the nanowires under the continuous illumination of light with above-or below-gap energies was slow, which indicates that photocurrent in the nanowires is surface-related rather than bulk-related. The photoresponse spectrum represents the above-and below-gap absorption bands for the photocurrents. The I -V characteristics under the illumination of the above-gap light are ohmic, but the characteristics under the illumination of the below-gap light are Schottky. This observation indicates that the above-gap light lowers the potential barrier built in the contact between the ZnO nanowires and electrodes, but that the below-gap light does not lower the potential barrier.

, has been utilized as capacitor dielectrics and gate oxides in memory devices owing to its high dielectric constant, very low permeability, and high thermal conductivity.[1±3] In nanotube-based electronics, the importance of Al 2 O 3 nanotubes will increase, for these tubes will be useful in the fabrication of nanocables, nanojacks, [4] and nanocapacitors.[5] Al 2 O 3 nanotubes have recently been prepared by etching a porous alumina membrane template, [6] by using a carbon nanotube template, [7] or via an electrochemical anodization of Al/Si in dilute sulfuric acid using porous alumina films. [4,5] Nevertheless, these preparation methods have some difficulties in controlling and achieving uniformity of the thickness of the Al 2 O 3 nanotubes. In the study reported here, an easy and convenient route to fabricate Al 2 O 3 nanotubes with conformally uniform thickness using ZnO nanowires as templates was developed. First, ZnO/Al 2 O 3 core/shell nanofibers were prepared by depositing Al 2 O 3 on ZnO nanowires by atomiclayer deposition (ALD), then amorphous Al 2 O 3 nanotubes were fabricated by wet-etching the ZnO core nanowires in the ZnO/Al 2 O 3 core/shell nanofibers. The thickness of the Al 2 O 3 nanotubes was precisely controlled by the number of ALD reaction cycles. A scanning electron microscopy (SEM) image of bare ZnO nanowires, and transmission electron microscopy (TEM) images of a ZnO/Al 2 O 3 core/shell nanofiber and an Al 2 O 3 nanotube are presented in Figure 1. The SEM image of Figure 1a shows a side view of the ZnO nanowires synthesized on a Si substrate by a thermal evaporation procedure; the diameter of the nanowires is in the range of 20±200 nm, and the length is 20±30 lm. In this procedure, a thick polycrystalline ZnO layer was first formed on the Si substrate by thermal evaporation of ZnO powder, and the ZnO nanowires were then COMMUNICATIONS 422

The oxygen plasma surface treatment of silicon and glass was studied for improving the characteristics of anodic bonding. By contact-angle measurements, we calculated the surface energy which is the sum of polar and dispersion components. The results showed that oxygen-plasma-induced distinctive high-polar and low-dispersion characteristics and caused the total surface energy to increase even at low power or short plasma exposure times for both silicon and glass surfaces. The highly polar-component-induced surface was maintained for over 100 days. On increasing plasma power and exposure time, it was observed that surface roughness increased. The oxygen plasma treatment was significantly efficient to reduce the contaminants on the surface, which was the main factor in degrading bonding strength and electrical properties of the interface. In the tensile test, the oxygen plasma treatment led to higher bonding strength than a conventional anodic bonding method. © 2001 The Electrochemical Society. All rights reserved.

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White-colored materials synthesized by a thermal annealing of milled GaN powders at 930 °C in a nitrogen atmosphere were identified to be monoclinic β-Ga2O3 nanowires by x-ray diffraction and scanning electron microscopy. High-resolution transmission electron microscopy revealed that these nanowires are single nanocrystals, and energy dispersive x-ray indicated that these nanomaterials are free of any metals. In addition, bundles of these crystalline nanowires in the rectangular-pole shape are a few centimeters in length.