Compositional control of homogeneous InGaN nanowires with the In content up to 90.

Homogenous InGaN nanowires with a controlled indium composition up to 90% are grown on GaN/c-AlO templates by catalyst-free hydride vapor phase epitaxy using InCl and GaCl as group III element precursors. The influence of the partial pressures on the growth rate and composition of InGaN nanowires is investigated. It is shown how the InN mole fraction in nanowires can be finely tuned by changing the vapor phase composition.

Metal organic vapour-phase epitaxy growth of GaN wires on Si (111) for light-emitting diode applications.

GaN wires are grown on a Si (111) substrate by metal organic vapour-phase epitaxy on a thin deposited AlN blanket and through a thin SiNx layer formed spontaneously at the AlN/Si interface. N-doped wires are used as templates for the growth of core-shell InGaN/GaN multiple quantum wells coated by a p-doped shell. Standing single-wire heterostructures are connected using a metallic tip and a Si substrate backside contact, and the electroluminescence at room temperature and forward bias is demonstrated at 420 nm.

Carrier depletion and exciton diffusion in a single ZnO nanowire.

Carrier depletion and transport in a single ZnO nanowire Schottky device have been investigated at 5 K, using cathodoluminescence measurements. An exciton diffusion length of 200 nm has been determined along the nanowire axis. The depletion width is found to increase linearly with the reverse bias.

Size effects in mechanical deformation and fracture of cantilevered silicon nanowires.

Elastic modulus and fracture strength of vertically aligned Si [111] nanowires (ø = 100-700 nm) in an as-grown state have been measured using a new, multipoint bending protocol in an atomic force microscope. All wires showed linear elastic behavior, spring constants which scale with (length)(3), and brittle failure at the wire-substrate junction. The "effective" Young's modulus increased slightly (100 --> 160-180 GPa) as wire diameter decreased, but fracture strength increased by 2-3 orders of magnitude (MPa --> GPa).

Control of gold surface diffusion on si nanowires.

Silicon nanowires (NW) were grown by the vapor-liquid-solid mechanism using gold as the catalyst and silane as the precursor. Gold from the catalyst particle can diffuse over the wire sidewalls, resulting in gold clusters decorating the wire sidewalls. The presence or absence of gold clusters was observed either by high angle annular darkfield scanning transmission electron microscopy images or by scanning electron microscopy.