A nanowatt UV photoconductive detector made up of ultra-long (approximately 100 microm) ZnO bridging nanowires has been fabricated by a single-step chemical vapor deposition (CVD) process. The electrodes, forming comb-shaped thick ZnO layers, and the sensing elements, consisting of ZnO nanowires bridging the electrodes, were fabricated simultaneously in a single-step CVD process. The device sho...

A systematic study was conducted on the fabrication, structural characterization, and transport properties of Zn nanowires with diameters between 40 and 100 nm. Zinc nanowires were fabricated by electrodepositing Zn into commercially available polycarbonate (PC) or anodic aluminum oxide (AAO) membranes. By controlling the electrodeposition process, we found that the nanowires can be single-crys...

We present a general approach to growing ZnO nanowires on arbitrary, high melting point (above 970 degrees C) substrates using the vapor-liquid-solid (VLS) growth mechanism. Our approach utilizes the melting point reduction of sufficiently small (5 nm diameter) Au particles to provide a liquid catalyst without substrate interaction. Using this size-dependent melting effect, we demonstrate catal...

Functional nanowires, made from materials such as zinc oxide, offer the promise of energy scavenging and precise sensing due to their vibrational properties, but their high intrinsic resonance frequencies (in the kilohertz to megahertz range) have limited the applications in nanotechnology. In this paper, we describe a method for introducing a new type of resonance at ultralow frequencies in Zn...

Large-quantity ~grams! one-dimensional ZnO nanowires of different sizes have been synthesized by a simple thermal evaporation of ZnO powder in a tube furnace at a temperature controlled to 1000– 1200 °C and pressure to 1–2 Torr air. A mixture of ZnO and graphite powder was used as the source. Fine graphite flakes were used to promote the growth. The graphite flakes are the key for large-quantit...

ZnO nanowire nucleation mechanism and initial stages of nanowire growth using the carbothermal reduction technique are studied confirming the involvement of the catalyst at the tip in the growth process. Role of the Au catalyst is further confirmed when the tapering observed in the nanowires can be explained by the change in the shape of the catalyst causing a variation of the contact area at t...

Branched hierarchical CdS/ZnO nanocomposites have been synthesized for application toward photocatalytic fine-chemical synthesis. Growing ZnO nanorods on the surface of CdS nanowires boosts the light harvesting efficiency and charge separation as well as fast charge transport and collection. A Z-scheme mechanism under artificial solar light is also proposed.

Zinc nanowires of serpentine geometry have been grown on conducting plastic and glass substrates in an aqueous electrolyte at an anomalously low temperature of 0 °C by a one-step, template-free electrodeposition technique. These nanowires are of several micrometers long and with a diameter of 20-200 nm. These nanowires are also single-crystalline and found to be coated with a 5 nm thick ZnO she...

In this work, we design and fabricate a wireless system with the main operating device based on zinc oxide (ZnO) nanowires. The main operating device is based on piezoelectric nanogenerator (NG) achieved using ZnO nanowires grown hydrothermally on paper substrate. The fabricated NG is capable of harvesting ambient mechanical energy from various kinds of human motion, e.g., footsteps. The harves...

Several key advances were accomplished within this project in the last year. These advances are subdivided in materials development, device development and modeling and simulation. Highly doped ZnO nanowires were synthesized and characterized. The goal is to use them as a solution-processable alternative to ITO for transparent electrodes. Appropriate characterization techniques for these nanoma...