Noble-metal nanoparticles embedded in dielectric matrices are considered to have practical applications in ultrafast all-optical switching devices owing to their enhanced third-order nonlinear susceptibility, especially near the surface-plasmon-resonance (SPR) frequency. Here we present the use of a microreactor approach to the fabrication of a self-organized photosensitive gold nanoparticle chain encapsulated in a dielectric nanowire. Such a hybrid nanowire shows pronounced SPR absorption. More remarkably, a strong wavelength-dependent and reversible photoresponse has been demonstrated in a two-terminal device using an ensemble of gold nanopeapodded silica nanowires under light illumination, whereas no photoresponse was observed for the plain silica nanowires. These results show the potential of using gold nanopeapodded silica nanowires as wavelength-controlled optical nanoswitches. The microreactor approach can be applied to the preparation of a range of hybrid metal-dielectric one-dimensional nanostructures that can be used as functional building blocks for nanoscale waveguiding devices, sensors and optoelectronics.

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Influence of a SiO2 ultrathin film on n-ZnO/p-silicon nanowires photodiodes has been investigated. With a SiO2 thin layer, the diode characteristics can be significantly improved, which exhibits high responsivity under a reverse bias. Based on the electron conversion efficiency measurement, we show that the ultrathin SiO2 layer with positive fixed charges not only acts as a hole blocking layer but also helps the photogenerated electrons to tunnel through the barrier. In addition, the SiO2 layer can effectively passivate the defects generated by wet etching process. It is expected that our approach can be extended to many other nanoscale heterojunction devices.

Silicon carbide (SIC) films were synthesized by low-pressure chemical vapor deposition using Si2H6 and C2H2 as the reactant gases at 873 K and 3.3 Torr total pressure. The film-formation mechanism was studied by the "macro/microcavity method' which determines the kinetics of the reaction and the sticking probability of the film-forming species, simultaneously. The reaction of Si2H6 in the presence of C2H2 occurred both on the surface of the substrate and in the gas phase. The surface reaction of Si2H6 was retarded strongly by the addition of C2H2 while the gas:phase reaction was not. Th~ film forming species included (i) Si2H~, directly depositing on the substrate with a sticking probability of 5 • 10-6; (it) Sill2, an initial product of the gas-phase decomposition of Si2H6, diffusing to the wall and reacting with a sticking probability of 1;and (iii) a Si and C containing intermediate, most plausibly, SiH3C~-CH, produced by the gas-phase reaction of Sill2 with C2H2, depositing on the substrate with a sticking probability of 0.1. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 129.49.23.145 Downloaded on 2015-03-16 to IP ABSTRACTMetal contamination levels are a growing concern in integrated circuit manufacturing because they degrade electrical performance. This work uses statistical design of experiments to determine deposition characteristics of metal contaminants onto silicon surfaces from process chemicals that are used in wafer cleaning. Copper, gold, molybdenum, silver, lead, chromium, tin, titanium, manganese, and tungsten were added to buffered oxide etchant and HF solutions. Wafers were immersed in these solutions and evaluated by total reflectance x-ray fluorescence spectroscopy surface analysis. Most contaminant deposition characteristics are simple, dependent on bath type and contamination level alone. Some contaminant deposition characteristics are complex, dependent on multifactors including bath type, contaminant level, and the presence of other contaminants as well.

This work investigates a nanoporous aluminum nitride (AlN) layer prepared using an anodic aluminum oxide (AAO) process and its application as a buffer layer for a GaN-based light-emitting diode (LED) fabricated on sapphire substrate. Following this AAO process, the average pore spacing and pore diameter of the nanoporous AlN layer were in the ranges 180-200 nm and 100-150 nm, respectively. The light output power of the GaN-based LED with a nanoporous AlN layer was about 53% higher than that of a GaN-based LED without a nanoporous AlN layer at an injection current of 20 mA. At an injection current of 80 mA, the light output power was increased by about 34%.

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InGaN blue light-emitting diodes (LEDs) were fabricated on a sapphire substrate with a ZnO nucleation layer that was deposited by the sol-gel method. Typical current-voltage (I-V) characteristics of the InGaN blue LEDs with a ZnO nucleation layer have a forward-bias voltage of 3.25 V at an injection current of 20 mA, and reverse currents of 2.33 × 10 −8 and 5.91 × 10 −7 A at reverse biases of 10 and 20 V, respectively. The InGaN blue LEDs have an ideality factor n of 1.27 at a forward bias of 1.8 V. The external quantum efficiency at an injection current of 20 mA was measured to be 12.82%. The light output power reached as high as 23.2 mW at a forward current of 100 mA.