A solid phase epitaxy (SPE) technique was developed to grow p+ aluminum-doped crystalline Si in a fully CMOS compatible process. This paper describes the experimental conditions leading to the selective growth of nanoscale single crystals where the location and dimensions are well controlled, even in the sub-100 nm range. The SPE Si crystals are defined by conventional lithography, show excellent electrical characteristics, and are uniform over the whole wafer. Fifty nanometer thick p+ SPE Si crystals were used to fabricate p+-n diodes and p+-n-p bipolar junction transistors. The high quality of the SPE Si and the remarkable control of the whole process, even in the sub-100 nm range, make this module directly usable for Si-based nanodevices.

We report the first large-scale synthesis of single crystal InSb nanowires using vapor-liquid-solid (VLS) transport process. Narrow growth window for achieving single crystal InSb nanowires has been discovered. Our batch produced InSb nanowires are 50-180 nm in diameter and 10-30 μ in length. Materials composition analysis by Energy-Dispersive X-ray Spectroscopy (EDAX) reveals that the as-grown InSb nanowires are pure single crystals of InSb. Structural analysis by High Resolution Transmission Electron Microscopy (HRTEM) and Selected Area Electron Diffraction (SAED) reveals that InSb nanowires have body-centered-cubic (BCC) crystal structure with cubic unit cell length of 10.15 Å. The nanowire growth direction is found to be [001], 45 degrees toward the most dense lattice planes in BCC structure.

Metal patterned lines on a substrate have been annealed and broken down into isolated linear arrays of alloyed metal nanoscale droplets. These droplets are selectively fabricated across large-scale areas by controlling the location metal is present on a substrate. The metal instability and formation into nanoscale particles forms similar to studies in Rayleigh Instability of metal at an elevated temperature. Experimental results discussed here show a change in droplet diameter and formation by controlling the metal width.

The growth of nanostructured material continues to attract attention for a number of applications, including highly sensitive gas sensors (due to the increased surface area), and photonic crystals (which require arrays of nanostructures). Even though nanostructures can be formed through self-assembly, they often do not possess the high crystal quality of those grown using vapour liquid solid (VLS) techniques; also, with VLS the feature size and placement can be easily controlled. To achieve VLS growth, however, several parameters have to be considered specific to the material of interest. In this study, we examine VLS growth of both InN (infrared) and ZnO (ultraviolet) nanostructures.

Germanium dioxide nanowires have gained considerable interest lately [1, 2], in part this is due to the bandgap of 2.44 eV, and high index of refraction, n = 1.63 [3]. In this paper we report a simple fabrication technique for making large quantities of GeO2 wires with diameters ranging from 40 nm to >500 nm on different substrates. The nanowires show strong preferential growth at gold catalyst locations on the silicon substrate. The nanowires were grown on silicon, tungsten, quartz, and nickel substrates at locations where a ∼10 nm film of Au was deposited. Growth and diameter of the wires are strongly dependent on the background gas (room air) and the length of time exposed to air at the growth temperature. Presented here are the growth conditions, and images of the resulting wires fabricated. The products are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) as well as X-Ray diffraction (XRD). The observations show the products are crystalline GeO2 nanowires.

We have investigated the absorption spectrum and strength of InyGa1−yAs1−xNx quantum wires. We show that compounds with varying fractions of indium and nitrogen, but similar band gaps have different absorption patterns. This behavior is related to the interplay between different effects as strain, which mainly affects the band offsets, and the increased electron mass in dilute nitride III-V semiconductors. We also study how the influence of these parameters changes with the optical band gaps associated to common optical telecommunication wavelengths. Our model calculations are performed in the parabolic band approximation and include excitonic effects.

Er-doped GaN rod-shaped low-dimensional structures have been synthesized on the surface of a silicon (001) substrate by the direct reaction of Ga, NH3 and Er using a catalyst-assisted chemical vapor deposition technique. The low-dimensional nanostructures were characterized spectrocopically analyzing the hypersensitive 4G11/2 and 2H11/2 bands of Er3+ located at 375 and 425 nm, respectively. Green and near-infrared (IR) emission produced by these Er-doped GaN low-dimensional structures has been observed under excitation at 488 and 543 nm in a confocal microscope.