Nanowires : synthesis, properties, assembly and applications : symposium held December 1-5, 2008, Boston, Massachusetts, U.S.A.

Given the interest, fascination, and rapid development in the field of nanowires, this volume offers a well-timed overview of critical issues related to nanowires, as well as recent progress in synthesis, structure, properties and devices. Topics include: synthesis, with control over composition, size, shape, position, geometry, doping, alloying, and heterostructures; properties-mechanical, electronic, optical, thermal, magnetic, ionic, phase transformational, and chemical; assembly and integration-methods for organizing nanowires, multiple length scale pattern formation, heterogeneous integration, and assembly architecture; and applications-functional devices and systems for electronics, photonics, sensors, and renewable energy

Characterization of novel powder and thin film RGB phosphors for field emissions display application

The spectral response, brightness and outgassing characteristics of new, low-voltage phosphors for application in field-emission flat-panel displays, are presented. The tested phosphor materials include combustion synthesized powders and thin films prepared by RF-diode or magnetron sputtering, laser ablation and molecular beam epitaxy. These cathodoluminescent materials are tested with e-beam excitation at currents up to 50 {mu}A within the 200-2000V (e.g. {open_quotes}low-voltage{close_quotes}) and 3-8 kV (e.g. {open_quotes}medium voltage{close_quotes}) ranges. The spectral coordinates are compared to commercial low-voltage P22 phosphors. Phosphor outgassing, as a function of time is measured with a residual gas analyzer at fixed 50 {mu}A beam current in the low-voltage range. We find that levels of outgassing stabilize to low values after the first few hours of excitation. The desorption rates measured for powder phosphor layers with different thickness are compared to desorption from thin films

High electrical conductivity and high porosity in a Guest@MOF material : Evidence of TCNQ ordering within Cu₃BTC₂ micropores

The host-guest system TCNQ@Cu3BTC2 (TCNQ = 7,7,8,8-tetracyanoquinodimethane, BTC = 1,3,5-benzenetricarboxylate) is a striking example of how semiconductivity can be introduced by guest incorporation in an otherwise insulating parent material. Exhibiting both microporosity and semiconducting behavior such materials offer exciting opportunities as next-generation sensor materials. Here, we apply a solvent-free vapor phase loading under rigorous exclusion of moisture, obtaining a series of the general formula xTCNQ@Cu3BTC2 (0 ≤ x ≤ 1.0). By using powder X-ray diffraction, infrared and X-ray absorption spectroscopy together with scanning electron microscopy and porosimetry, we provide the first structural evidence for a systematic preferential arrangement of TCNQ along the (111) lattice plane and the bridging coordination motif to two neighbouring Cu-paddlewheels, as was predicted by theory. For 1.0TCNQ@Cu3BTC2 we find a specific electrical conductivity of up to 1.5 × 10-4 S cm-1 whilst maintaining a high BET surface area of 573.7 m2 g-1. These values are unmatched by MOFs with equally high electrical conductivity, making the material attractive for applications such as super capacitors and chemiresistors. Our results represent the crucial missing link needed to firmly establish the structure-property relationship revealed in TCNQ@Cu3BTC2, thereby creating a sound basis for using this as a design principle for electrically conducting MOFs.</p