We report large-scale synthesis of silica nanowires (SiONWs) using an excimer laser ablation method. Silica was produced in the form of amorphous nanowires at a diameter of ∼15 nm and a length up to hundreds micrometers. The SiONWs emit stable and high brightness blue light at energies of 2.65 and 3.0 eV. The intensity of the emission is two orders of magnitude higher than that of porous silicon. The SiONWs may have potential applications in high-resolution optical heads of scanning near-field optical microscope or nanointerconnections in future integrated optical devices.

We report the large-scale synthesis of silicon nanowires (SiNWs) using a simple but effective approach. High purity SiNWs of uniform diameters around 15 nm were obtained by sublimating a hot-pressed silicon powder target at 1200 °C in a flowing carrier gas environment. The SiNWs emit stable blue light which seems unrelated to quantum confinement, but related to an amorphous overcoating layer of silicon oxide. Our approach can be used, in principle, as a general method for synthesis of other one-dimensional semiconducting, or conducting nanowires.

The existence of large densities of surface states on InAs pins the surface Fermi level above the conduction band and also degrades the electron mobility in thin films and nanowires. Field effect transistors have been fabricated and characterized in the "as fabricated" state and after surface passivation with 1-octadecanethiol (ODT). Electrical characterization of the transistors shows that the subthreshold slope and electron mobility in devices passivated with ODT are superior to the respective values in unpassivated devices. An X-ray photoelectron spectroscopy study of ODT passivated undoped InAs nanowires indicates that sulfur from ODT is bonded to In on the InAs nanowires. Simulations using a two-dimensional device simulator (MEDICI) show that the improvements in device performance after ODT passivation can be quantified in terms of a decrease of interface trap electron donor states, shifts in fixed interfacial charge, and changes in body and surface mobilities.

Colloidal InP quantum wires are grown by the solution-liquid-solid (SLS) method, and passivated with the traditional quantum dots surfactants 1-hexadecylamine and tri-n-octylphosphine oxide. The size dependence of the band gaps in the wires are determined from the absorption spectra, and compared to other experimental results for InP quantum dots and wires, and to the predictions of theory. The photoluminescence behavior of the wires is also investigated. Efforts to enhance photoluminescence efficiencies through photochemical etching in the presence of HF result only in photochemical thinning or photo-oxidation, without a significant influence on quantum-wire photoluminescence. However, photo-oxidation produces residual dot and rod domains within the wires, which are luminescent. The results establish that the quantum-wire band gaps are weakly influenced by the nature of the surface passivation, and that colloidal quantum wires have intrinsically low photoluminescence efficiencies. † Current address: Stanford