The widely used 'silicon-on-insulator' (SOI) system consists of a layer of single-crystalline silicon supported on a silicon dioxide substrate. When this silicon layer (the template layer) is very thin, the assumption that an effectively infinite number of atoms contributes to its physical properties no longer applies, and new electronic, mechanical and thermodynamic phenomena arise, distinct from those of bulk silicon. The development of unusual electronic properties with decreasing layer thickness is particularly important for silicon microelectronic devices, in which (001)-oriented SOI is often used. Here we show--using scanning tunnelling microscopy, electronic transport measurements, and theory--that electronic conduction in thin SOI(001) is determined not by bulk dopants but by the interaction of surface or interface electronic energy levels with the 'bulk' band structure of the thin silicon template layer. This interaction enables high-mobility carrier conduction in nanometre-scale SOI; conduction in even the thinnest membranes or layers of Si(001) is therefore possible, independent of any considerations of bulk doping, provided that the proper surface or interface states are available to enable the thermal excitation of 'bulk' carriers in the silicon layer.

Low cost, direct writing of conductive traces is highly desired for applications in nanoelectronics, photonics, circuit repair, flexible electronics, and nanoparticle-based gas detection. The unique ability of Dip Pen Nanolithography ͑DPN ® ͒ to direct write a variety of materials onto suitable surfaces with nanoscale resolution and area-specific patterning is leveraged in this work. We present a direct-write approach toward creating traces with commercially available silver nanoparticle ͑AgNP͒-based inks using DPN. In this work we demonstrate submicron AgNP feature creation together with a discussion on the ink transport mechanism.

Quantitative electric force microscopy ͑EFM͒ is usually restricted to flat samples, because vertical sample topography traditionally makes quantitative interpretation of EFM data difficult. Many important samples, including self-assembled nanostructures, possess interesting nanoscale electrical properties in addition to complex topography. Here we present techniques for analysis of EFM images of such samples, using voltage modulated EFM augmented by three-dimensional simulations. We demonstrate the effectiveness of these techniques in analyzing EFM images of self-assembled SiGe nanostructures on insulator, report measured dielectric properties, and discuss the limitations sample topography places on quantitative measurement.

Single-crystal iron boride (Fe3B) nanowires were synthesized on Pt and Pd (Pt/Pd) coated sapphire substrates by a chemical vapor deposition method at 800 °C using boron triiodide (BI3) and iron iodide (FeI2) as precursors. Morphology of the Fe3B nanowires can be controlled by manipulating the Pt/Pd film thickness and the growth time. Transmission electron microscopy and selected area electron diffraction were used to analyze the crystal structures of these novel materials. Electron energy-loss spectroscopy and X-ray energy-dispersive spectroscopy studies on these nanowires confirm that they are composed of boron and iron. Scanning electron microscopy was employed to observe the morphology of these nanomaterials. The typical size of the iron boride nanowires is about 5−50 nm in width and 2−30 μm in length. The vapor−liquid−solid (VLS) growth process is shown to be the growth mechanism of the Fe3B nanowires. Room temperature magnetic force microscopy investigations on the iron boride nanowires suggest that they are ferromagnetic nanowires with a single-domain configuration.