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The plastic deformation features of intrinsic brittle-featured SiC nanowires by high resolution electron microscopy have been investigated. Strong plastic deformation strain fields were observed in a bent SiC nanowire. The achieved localized strain reaches about 1.5%. Localized lattice bending, atomic lattice disordering, and amorphization are contribution factors to achieve the plastic deformation. The projected Si–Si bonding angle distribution on the (110) atomic plane demonstrates the disordering features of the bent SiC nanowire. Buckling is found at the compressive side of the bent SiC nanowire. Growth bending can be achieved through {111} twinning and phase transformation from 3C to 2H. [ABSTRACT FROM AUTHOR]

Photoconductors based on V-grooved Al[sub 0.5]Ga[sub 0.5]As/GaAs multiple quantum wires (QWR) were fabricated. The geometric structure of the QWR was carefully characterized by transmission electron microscopy and spatially resolved microphotoluminescence measurements. Infrared response at 9.2 μm is observed from the photocurrent spectrum measured at 80 K. It is attributed as the intersubband transition in the quantum wire region. Due to the effective quantum confinement from the two (111)-surfaces forming the V groove, the overlapping between the ground state in the QWR and the one in the vertical quantum well is very small. This explains the weak photocurrent signal from the QWR photodetector. Theoretical design for a better wave function overlapping and optical coupling is outlined from the analysis of two-dimensional spatial distributions of the wave functions. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Studies the asymmetric double GaAs/AlGaAs V-grooved quantum wires, grown by low pressure metalorganic chemical vapor deposition using photoluminescence spectroscopy. Selective treatment of the structure by ion implantation at different arsenic doses after growth; Reduction of the efficiency of the emissions from the implanted well regions.

We present experimental results for the transmission T, haze H, sheet resistance Rs, and its spatial fluctuations ΔRs for silver nanowire films. Mie light scattering theory of nanowires is developed to predict both T and H as a function of diameter D of wires and the surface fraction [lowercase_phi_synonym]s covered by the wires. Percolation theory is used to derive an equation for Rs in terms of D, the aspect ratio of wires D/L and [lowercase_phi_synonym]s. The critical exponent t for percolation of Rs is found to be 1.23 in close agreement with theoretical results for 2D random resistive networks (t = 1.3). These equations show the importance of both the distributions of diameter and aspect ratio of wires / to predict the optical and electrical properties. Spatial fluctuations ΔRs/Rs can also be significant in these films and be greater than 10% as [lowercase_phi_synonym]s approaches the critical percolation concentration [lowercase_phi_synonym]c. We show that the calculated T versus Rs and H versus Rs curves are in good agreement with the experimental data. We propose figures of merit for percolating nanowire films in terms of high T, low H, and low Rs to order the quality of films for touch screen applications. The results show that D < 50 nm and L > 5 μm are needed to achieve low haze H < 1%, high transmission T > 90%, together with low Rs ∼ 100 ࡎ/sq for touch screen applications. Finally, we present experimental and theoretical results of the real and imaginary refractive indices of AgNW/polymer nanocomposites, and find that the Van De Hulst model is more accurate than the Maxwell Garnett models. [ABSTRACT FROM AUTHOR]

A crystallized Si2Sb2Te5 thin film was observed to extrude single-crystalline [0001] oriented tellurium nanowires at room temperature. The single crystalline Te nanowires nucleation and extruded outgrowth can be greatly accelerated by electron-beam-illumination (EBI) in a transmission electron microscope by an order as high as four. The EBI-enhanced outgrowth speed of Te nanowires is a function of electron beam flux and can be described as v=k ln(J+m). This Te nanowires self-outflow phenomenon comes from a decomposition process of the Si2Sb2Te5 matrix and provides an interesting model and mechanism of the nanowires’ growth, which is distinctive to the vapor-liquid-solid (VLS) mechanism. [ABSTRACT FROM AUTHOR]

We report a 5 nm thick V-shaped AlGaAs/GaAs single quantum wire (QWR) that showed high photoluminescence (PL) thermal stability as a result of our recent progress in fabrication techniques. The integrated PL intensity of the QWR sample was quenched only by a factor of about 2.5 when the temperature was increased from 5 to 300 K. This sample also showed higher PL thermal stability over the whole temperature range than a 5 nm thick single quantum well reference sample grown under similar conditions. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We report the first systematic investigation of the temperature-dependent carrier transferring processes of very short period V-grooved GaAs/AlGaAs quantum wire superlattice structures grown by flow rate-modulated metal-organic vapor phase epitaxy. The one monolayer (1 ML) fluctuation causes carrier confinement in sidewall (111) facet superlattice structures, and is shown to play an important role in the carrier transferring process. At low temperatures, the carrier transfer is blocked by the barriers of 1 ML fluctuation, while at high temperatures the carrier transfer from (111) superlattice to the wire region is shown to be very efficient after thermally overcoming the barriers. The temperature-dependent decay times of the different parts give direct evidence of the carrier transferring process, which demonstrates that the carriers can trap into the wire region within 50 ps at temperatures higher than 100 K. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The luminescence intensity is strongly enhanced by introducing a size disordering into the AlGaAs/GaAs quantum-wire (QWR) superlattice (SL). The intensity increases with temperature due to the carrier transfer from the SL to the QWR and then decreases less than that of a regularly ordered QWRSL due to the carrier localization caused by the size disordering. [Copyright &y& Elsevier]