Nanowire electrons

Figure 11.2. Nanowire electronic and optical properties, (a) Schematic of an NW-FET used to characterize electrical transport properties of individual NWs. (inset) SEM image of an NW-FET two metal electrodes, which correspond to source and drain, are visible at the left and right sides of the image, (b) Current versus voltage for an n-type InP NW-FET. The numbers inside the plot indicate the corresponding gate voltages (Vg). The inset shows current versus Vg for Fsd of 0.1 V. (c) Real-color photoluminescence image of various NWs shows different color emissions, (d) Spectra of individual NW photoluminescence. All NW materials show a clean band-edge emission spectrum with narrow FWHM around 20nm. (See color insert.)...

McAlpine, M. C. Friedman, R. S. Lieber, C. M. 2005. High-performance nanowire electronics and photonics and nanoscale patterning on flexible plastic substrates. Proc. IEEE 93 1357-1363. 

Wang W, Li D, Tian M, Lee Y-C, Yang R (2012) Wafer-scale fabrication of silicon nanowire arrays with controllable dimensions. Appl Surf Sci 258 8649-8655 Weisse JM et al. Thermal conductivity in porous silicon nanowire arrays. Nanoscale Res Lett 7 554 Weisse JM, Lee CH, Kim DR, Zheng X (2012) Fabrication of flexible and vertical silicon nanowire electronics. Nano Lett 12 3339-3343... 

Attention has been given to the synthesis of bimetallic silver-gold clusters [71] due to their effective catalytic properties, resistance to poisoning, and selectivity [72]. Recently molecular materials with gold and silver nanoclusters and nanowires have been synthesized. These materials are considered to be good candidates for electronic nanodevices and biosensors [73]. 

Bates et al. reported the construction and characterization of a gold nanoparticle wire assembled using Mg -dependent RNA-RNA interactions for the future assembly of practical nanocircuits [31]. They used magnesium ion-mediated RNA-RNA loop-receptor interactions, in conjunction with 15 nm or 30 nm gold nanoclusters derivatized with DNA to prepare self-assembled nanowires. A wire was deposited between lithographically fabricated nanoelectrodes and exhibited non-linear activated conduction by electron hopping at 150-300 K (Figure 16). 

FIG. 20-24 High -resolution TEM image of Si nanowires produced at 500 C and 24.1 MPa in supercritical hexane from gold seed crystals. Inset Electron diffraction pattern indexed for the <111> zone axis of Si indicates <110> growth direction. [Reprinted with permission from Lu et al. Nano Lett., 3(1), 93-99 (2003). Copyright 2003 American Chemical Society. ]... 

Of the various semiconductors tested to date, Ti02 is the most promising photocatalyst because of its appropriate electronic band structure, photostability, chemical inertness and commercial availability. But currently, a variety of nanostmctured Ti02 with different morphologies including nanorods, nanowires, nanostmctured films or coatings, nanotubes, and mesoporous/nanoporous structures have attracted much attention. 

The semiconductor structure is crucial for both electron injection and charge transport after the exciton separation. Meng et al. [35] published a theoretical study focused on the electron injection mechanism in dyad anthocyanine-Ti02 nanowires. 

A break junction can also be created by passing a current (0.5-1.0 V) through an Au nanowire (<20 nm diameter) defined by electron-beam lithography and shadow evaporation. Such electromigrated break junctions (EMBJs) have yielded reproducible 1-3 nm gaps between electrodes [48-50]. 

Although adequate materials and devices are essential, successful manufacturing will require other capabilities as well. First, the process must have high yield, which implies low variability, and provide robust stability to environmental factors. To produce the envisioned products, there must be readily available electronic design tools that can adequately simulate both device and circuit performance. Although some of these computer-aided design tools are available from microelectronics technology, others must either be modified, because of the differences in the thin-hlm devices, or created anew because the devices have no equivalent (nanowires and nanotubes). 

Patolsky, F. Timko, B. R Zheng, G. Lieber, C. M. 2007. Nanowire-based nano-electronic devices in the life sciences. MRS Bull. 32 142-149. 

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