Metal Nanogap Memory: Performances and Switching Mechanism.

The nanogap memory (NGM) device, emerging as a promising nonvolatile memory candidate, has attracted increasing attention for its simple structure, nano/atomic scale size, elevated operating speed, and robustness to high temperatures. In this study, nanogap memories based on Pd, Au, and Pt were fabricated by combining nanofabrication with electromigration technology. Subsequent evaluations of the electrical characteristics were conducted under ambient air or vacuum conditions at room temperature.

Physical mechanism of field modulation effects in ion implanted edge termination of vertical GaN Schottky barrier diodes.

In this study, the physical properties of F ion-implanted GaN were thoroughly studied, and the related electric-field modulation mechanisms in ion-implanted edge termination were revealed. Transmission electron microscopy results indicate that the ion-implanted region maintains a single-crystal structure even with the implantation of high-energy F ions, indicating that the high resistivity of the edge termination region is not induced by amorphization. Alternately, ion implantation-induced deep levels could compensate the electrons and lead to a highly resistive layer.

Toward High Carrier Mobility and Low Contact Resistance: Laser Cleaning of PMMA Residues on Graphene Surfaces.

Abstract: Poly(methyl methacrylate) (PMMA) is widely used for graphene transfer and device fabrication. However, it inevitably leaves a thin layer of polymer residues after acetone rinsing and leads to dramatic degradation of device performance. How to eliminate contamination and restore clean surfaces of graphene is still highly demanded.

Synthesis, characterization and properties of C60 nanocrystals, nanowires and hierarchical nanostructures.

In this article, we propose a simple and reproductive approach to prepare low dimension C60 nanostructures, which bases on the crystallization of C60 from volatile solution on the surface of substrates of different materials. The C60 nanowires that we obtained have a uniform shape with a length from 2 to 10 microm and a diameter from about 100 to 250 nm. In some cases, we could prepare the Y- or T-shaped nanostructures of C60, which may be due to the crystal growth simultaneous in different directions.

Hysteresis-free carbon nanotube field effect transistors without any post-treatment.

Out of hundreds of as-fabricated back-gated carbon nanotube field effect transistors we made, five devices which exhibit indiscernible hysteresis are found. The cause of these hysteresis-free devices is investigated based on the energy band and interface trap theory, and it is attributed to the bundling effect of single-walled carbon nanotubes which will result in a reduced bandgap in the single-walled carbon nanotube bundle compared with an isolated semiconducting carbon nanotube. A specific requirement of the SWNT bundle to satisfy the presumed explanation is also proposed.

Bicrystalline hematite nanowires.

Bicrystalline nanowires of hematite (alpha-Fe(2)O(3)) have been successfully synthesized by the oxidation of pure iron. The product was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM in combination with focal series reconstruction, energy-dispersive X-ray spectroscopy, and electron energy-loss spectroscopy. The bicrystalline nanowires have diameters of 20-80 nm and lengths up to 20 microm.

Thermally assisted tunnelling in ambipolar field-effect transistors based on fullerene peapod bundles.

We report the first detailed studies of the electrical transport behaviour of C(70) fullerene peapod bundles at various temperatures from 400 K down to 4 K. With electrical breakdown, we have prepared ambipolar (i.e.

Gate-controlled rectifying behavior in C70@SWNT networks.

We report the gate-controlled rectification behavior in C(70)@SWNT networks at room temperature in air. The electrical transport characteristics can be fitted well with the conventional Schottky diode model. The origin of the rectifying behavior in fullerene peapod networks device is qualitatively discussed.

[Raman spectroscopic study on the iron oxide film prepared by iron oxidation method].

Micro-Raman spectroscopy was used to investigate the chemical composition, microstructure and crystalline phase of an iron oxide sample with three-layer macro-structure prepared by iron oxidation. Two laser lines of 514 and 633 nm with a power of 0.5 mW on the sample were employed to excite the Raman spectra.

Discrete polarization absorption property of carbon nanotubes studied by using scanning near-field optical microscope.

By using scanning near-field optical microscopy (SNOM), we have observed the polarization phenomena of carbon nanotubes (CNTs), which were synthesized by pyrolysis of a metal phthalocyanine method. Using SNOM, an area of about 100 nm in the thin part of the honeycomblike aligned CNT can be investigated, where the CNTs are nearly parallel or cross aligned with only a few layers. Transmission intensity of the light absorption with constant height scan identified the thickness of the nanotube layers.