Selective Nanowire Growth Research Articles

Production of Metallic Alloy Nanowires and Particles Templated Using Tomato Mosaic Virus (ToMV).

We demonstrate a simple, low-energy method whereby tomato mosaic virus (ToMV) particles can be used to template the production of nanowires and particles consisting of alloys of gold (Au), platinum (Pt) and palladium (Pd) in various combinations. Selective nanowire growth within the inner channel of the particles was achieved using the polymeric capping agent polyvinylpyrrolidone (PVPK30) and the reducing agent ascorbic acid. The reaction conditions also resulted in the deposition of alloy nanoparticles on the external surface of the rods in addition to the nanowire structures within the internal cavity. The resulting materials were characterized using a variety of electron microscopic and spectroscopic techniques, which revealed both the structural and chemical composition of the alloys within the nanomaterials.

On-chip fabrication of ZnO-nanowire gas sensor with high gas sensitivity

ZnO-nanowire gas sensors were fabricated by a selective growth of nanowires on patterned Au catalysts thus forming nanowire air bridges or ‘ nanobridges’ between two Pt pillar electrodes. The gas sensing properties of nanobridge gas sensors were demonstrated using a diluted NO 2. The response, as a function of temperature, was highest at 225 °C and was linearly increased with the concentration of NO 2 in the range of 0.5–3 ppm and then showed a sign of saturation. Our sensor showed higher response compared with different types of sensors including ZnO nanocrystals, Sn- and In-doped ZnO thin film, or ZnO nanowires. The enhanced response was attributed to the additional modulation of the sensor resistance due to potential barrier at nanowire/nanowire junctions as well as the surface depletion region of each nanowire. Also nanobridge structure enabled fast recovery behavior because desorbed gas molecules can be easily swept away from the surface of ZnO nanowire without re-adsorption.

Selective growth of znic oxide nanowires on the metal electrodes

Although nanowires have been attractive subject of numerous researches due to their fascinating features, their compatibilities with industrial aspects of semiconductor technology should be considered for further progress. In this regard, the selective growth of nanowires on typical electrodes of semiconductor industry would be a step forward. In this study, we studied growth and alignment of ZnO nanowires on the desired position on several kinds of electrodes. As typical electrode materials aluminum, titanium, and platinum were considered. For patterned growth of ZnO nanowires on the selective area of Al, Ti, and Pt electrodes, Au catalytic layer was deposited on the desired position of the electrodes and the optimized processing conditions that the nanowires could be grown only where the patterned catalytic layer present were thoroughly examined.