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Interesting and Promising Nanomaterials and Nanoscale Structures

Interesting and Promising Nanomaterials and Nanoscale Structures. Yonhua Tzeng, Professor Electrical and Computer Engineering Auburn University, Alabama USA. July 7, 2003. Examples: 0-D: Nanoparticles/ Clusters Nanocrystals/ Q Dots 1-D: Nanowires/ Nanorods Nanotubes/Nanohorns

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Interesting and Promising Nanomaterials and Nanoscale Structures

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  1. Interesting and Promising Nanomaterials and Nanoscale Structures Yonhua Tzeng, Professor Electrical and Computer Engineering Auburn University, Alabama USA July 7, 2003

  2. Examples: 0-D: Nanoparticles/ Clusters Nanocrystals/ Q Dots 1-D: Nanowires/ Nanorods Nanotubes/Nanohorns 2-D: Thin Films/ SAMonolayers Superlattice/ Q Wells 3-D: Photonic Crystals Nanocomposites/NEMS

  3. 0-D: 10 nm diameter gold particles Anodic current vs. time for an ITO electrode in 0.3 M phosphate buffer/ 0.05 M EDTA following adsorption of 10 nm diameter gold particles to the electrode via DNA hybridization. The potential was held at 0.3 V vs. Ag/AgCl. ssDNA/gold nanoparticle conjugates were hybridized from a 1 pM solution. Arrow indicates light on. (bottom curve) Photocurrent vs. ssDNA-modified gold nanoparticle conjugate concentration. The circle indicates the photocurrent response in the absence of gold nanoparticles. http://www.ncsu.edu/chemistry/dlf/biomolecdetection.pdf

  4. 0-D: Composite Polymer Nanoparticles Synthesis of composite polymer nanoparticles and hollow polymer nanocapsules for bioencapsulation and intracellular delivery (Feldheim group, UNC) A hollow polypyrrole capsule templated with a 200 nm diameter gold particle. A metal particle serves as a template for the formation of thin skins of polymer. Dissolution of the particle following polymer formation results in a hollow capsule. Small molecules or larger biomolecules (horseradish peroxidase, avidin, DNA) may be trapped in the hollow core simply by attaching the molecule of interest to the particle prior to polymer formation. Enymes maintain their activity inside the hollow polymer capsules and are even protected to a certain extent by denaturing agents such as organic solvents. http://www.ncsu.edu/chemistry/dlf/polymernano.html

  5. 0-D: Magnetic Mineral Particles All magnetotactic bacteria contain magnetic mineral particles, e.g. Fe3O4, enclosed in membranes. In most cases the magnetosomes are arranged in a chain or chains, apparently fixed within the cell. The particle sizes range from ca. 40 to 100 nm, which are within the permanent single-magnetic-domain size range for magnetite. Magnetotactic bacterium strain MV-1 The migration speed of individual bacteria along the magnetic field lines depends on the field strength, but can be 90% or more of the forward swimming speed (up to 150 microns per second) of the cell. If the direction of the local magnetic field is reversed, the magnetotactic bacteria execute "U-turns" and continue migrating in the same direction relative to the local magnetic field. http://www.calpoly.edu/~rfrankel/mtbcalpoly.html

  6. http://www.wtec.org/biosensing/views/7_Ricco.pdf

  7. Metal Nanoparticle Arrays Mixing the thiol-terminated ligand with solutions of gold or silver nanoparticles results in nanoparticle arrays with symmetries and separation distances dictated by the bridging ligand. For example, the ligand shown above left results in gold or silver dimers (below left) while the ligand above right yields tetrahedral nanoparticle structures (below right). 10 nm diameter gold particles assembled into dimer and tetramer arrays. http://www.ncsu.edu/chemistry/dlf/opticalprop.html

  8. Gold nanoparticle complexes for bio-nuclear targeting Adenovirus Gold Nanoparticles Peptide-gold Nanoparticle The most efficient nulcear targeting in biology is accomplished by viruses, which commonly untilize different peptides for crossing each celluar membrane barrier. Gold nanoparticles of similar size and shape can be attached with many chemically distinct peptide “keys” and therapeutics by simply stirring them together in aqueous solutions. Gold is biocompatible. http://www.ncsu.edu/chemistry/dlf/biomaterialsynthesis.pdf

  9. 0-D: Nanocrystals/ Quantum Dots http://people.bu.edu/theochem/rabani.pdf

  10. 0-D: Nanocrystals/ Quantum Dots http://people.bu.edu/theochem/rabani.pdf

  11. Nanoparticles Well Studied in Isolation…Why Nanoparticle Arrays?A: Device IntegrationA: New Functionality in Ordered Ensembles http://daedalus.caltech.edu/research/presentations/original%20ppt%20files/UMinnesota1232001.ppt

  12. Nanocrystal Shape Control Boosts Efficiency of New Solar Cells Hybrid nanocrystal-polymer solar cell is made by blending CdSe nanocrystals with P3HT, a conducting polymer, to form a 200 nm thick film sandwiched between an aluminum top contact (orange) and a transparent bottom contact (blue). Nanocrystal shape affects the cell efficiency. Monochromatic quantum efficiencies of over 50% are achieved by using rod-like nanocrystals that are partially aligned with the path of current flow in the device. http://www.lbl.gov/~msd/PIs/Alivisatos/02/02-01_Nanosolar.ppt

  13. 1-D: Carbon Nanotubes Size and Shapes: High aspect ratio of carbon nanotubes and Metal-atom filled Nanotubes Nanostructure Science : R&D Status and Trends in Nanoparticles, Nanostructured Materials, and Nanodevices (1998) http://www.wtec.org/loyola/pdf/nano.pdfand Technology

  14. Field Emission Displays PixTech, Inc. announced the delivery of the first 12.1-inch Field Emission Display (FED) to the U. S. Army in 1999 Samsung’s Prototype CNT FED

  15. IBM team made a " voltage inverter " Aug 26, 2001 Atomic Force Microscope image showing the design of an intra-molecular logic gate. A single carbon nanotube (shaded in blue) is positioned over gold electrodes to produce two p-type carbon nanotube field-effect transistors in series. The device is covered by an insulated layer (called PMMA) and a window is opened by e-beam lithography to expose part of the nanotube. Potassium is then evaporated through this window to convert the exposed p-type nanotube transistor into an n-type nanotube transistor, while the other nanotube transistor remains p-type. Characteristics of the resulting intra-molecular voltage inverter. Open red circles are raw data for five different measurements on the same device (V=±2V). The blue line is the average of these five measurements. The thin straight line corresponds to an output/input gain of one. http://researchweb.watson.ibm.com/resources/news/20010827_logiccircuit.shtml

  16. Carbon nanotubes emit in the IR, 6 May 2003 The device does not rely on doping to create charge carriers, as silicon transistors do, but is 'biased' so that one part of the nanotube conducts electrons while the other conducts holes. This is achieved by the formation of Schottky barriers - potential barriers that electrons can tunnel through - at the source and drain. The electrons and holes recombined in the nanotube to emit infrared radiation at wavelengths longer than about 0.8 microns. This included light at a wavelength of 1.5 micrometres, which is widely used in fiber-optic communications The wavelength of the emission is determined by the band gap of the nanotube, which depends on the diameter of the nanotube. http://optics.org/articles/news/9/5/5/1

  17. Buckyball-filled nanotube The metallofullerenes (Gd@C82) and single-walled carbon nanotubes (SWNTs) were first formed. The nanotube was heated in dry air at 420 degrees Celsius to open both ends of the nanotube. The Gd@C82, once heated to a vapor, readily entered the opened tubes, and lined up inside the tubes at roughly 1 nanometer intervals. http://www.mtmi.vu.lt/pfk/funkc_dariniai/nanostructures/nanotubes.htm

  18. Space Elevator Need 30 times stronger than steel • Carbon at least 100 times stronger • Seattle-based HighLift Systems wants to build this within 20 years

  19. Resistivity of ErSi2 Nanowires on Silicon ErSi2 nanowires on a clean surface of Si(001). Resistance of nanowire vs its length. ErSi2 nanowire self-assembled along a <110> axis of the Si(001) substrate, having sizes of 1-5nm, 1-2nm and <1000nm, in width, height, and length, respectively. The resistance per unit length is 1.2M/nm along the ErSi2 nanowire. The resistivity is around 1cm, which is 4 orders of magnitude larger than that for known resistivity of bulk ErSi2, i.e., 35 cm. One of the reasons may be due to an elastically-elongated lattice spacing along the ErSi2 nanowire as a result of lattice mismatch between the ErSi2 and Si(001) substrate. http://www.riken.go.jp/lab-www/surf-inter/tanaka/gyouseki/ICSTM01.pdf

  20. Magnetic nanowires • Important for storage device applications • Cobalt, gold, copper and cobalt-copper nanowire arrays have been fabricated • Electrochemical deposition is prevalent fabrication technique • <20 nm diameter nanowire arrays have been fabricated Cobalt nanowires on Si substrate (UMass Amherst, 2000) http://www.me.berkeley.edu/nti/englander1.ppt

  21. Molecular nanowire with negative differential resistance at room temperature http://research.chem.psu.edu/mallouk/articles/b203047k.pdf

  22. When a bend is created in the waveguide, it is impossible for light to escape (since it cannot propagate in the bulk crystal). The only possible problem is that of reflection. However, the problem can be analyzed in a manner similar to one-dimensional resonant tunneling in quantum mechanics, and it turns out to be possible to get 100% transmission. The following picture depicts the electric field in a waveguide bend exhibiting 100% transmission. Waveguide Bends in Photonic Crystals http://ab-initio.mit.edu/photons/bends.html

  23. 1-D: Single mode optical waveguide in photonic crystals http://www.ntt.co.jp/RD/OFIS/active/2002pdfe/ct34_e.pdf

  24. 2-D: Thin Films; 3-D: Devices Gordon Moore forecasted the rapid pace of technology innovation in 1965. Today, "Moore’s Law" remains valid. http://www.intel.com/research/silicon/mooreslaw.htm?iid=sr+moore&

  25. 2-D: Thin Films http://www-inst.eecs.berkeley.edu/~ee143/f2002/Lectures/Lec_28.pdf

  26. 2-D: Thin Films Spintronics: Giant Magnetoresistance http://www.hgst.com/hdd/technolo/gmr/fig8.gif

  27. 2-D: Self-Assembled Monolayer (SAM) Self-assembly is a phenomenon in which atoms, molecules or groups of molecules arrange themselves spontaneously into regular patterns and even relatively complex systems without intervention from outside. http://www.mtmi.vu.lt/pfk/funkc_dariniai/nanostructures/molec_computer.htm

  28. Langmuir-type Adsorption I=Ioexp(-kt) Class Presentation by Noppadon Sathitsuksanoh, ELEC 7970, Auburn University, Summer 2003

  29. 2-D Nucleation and Growth jinstantaneous=atexp(-bt2) jprogressive=ct2exp(-dt3) Class Presentation by Noppadon Sathitsuksanoh, ELEC 7970, Auburn University, Summer 2003

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