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Nanotechnology 27th March, 2012


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Nanotechnology 27th March, 2012

Presentation for the Microelectronics and Nanotechnology Club, at CCNY.

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Nanotechnology 27th March, 2012

  1. 1. Nanotechnology Mohammad “Faissal” Halim Dorsinville GroupPhotovoltaics and Nonlinear Optics Tuesday, 27th March, 2012
  2. 2. What is Nanotechnology?Science and art of utilizing• Matter, at the nanoscale• Physical effects that only occur when matter is at the nanoscaleDefined Size Range: 1-100 nmSize Range of Interest: 1-10 nm
  3. 3. How Small Is Nano?
  4. 4. How Small Is Nano?
  5. 5. Why do we care? Stone Age Iron Age Modern Age /pressroom/kits/innovation /survey/Fab_Guy.jpgImprovement in quality of life, through advancements in materials.
  6. 6. The New ParadigmThe pursuit of materials that are:• Stronger  Nanotube reinforced materials• Lighter  Materials strong due to their internal structure• More absorbant  Higher sensitivity photodetectors• More luminescent  Better lighting• Faster  faster acting light filters, processor components• Possessive of new properties  More lubricating, can transmit light in unique ways Source: Source: Source:
  7. 7. Is This A New Way of Thinking?Material properties have always been tuned by• Sharpening  for stone tools• Heating  changes properties of wood• Annealing  changes the hardness of metals• Doping  changes the conductive properties of semiconductors ElectroplatingSmelting Doping /de/latin-america/amazon-basin /16615/Electronics_Electroplating_System.html /aluminum-smelting?size=_original
  8. 8. So, What Is New?• Why is the use of nanotechnology so different from how things have always been done?• Why can’t I get a grant unless my work has something to do with nanomaterials?
  9. 9. Pre-existing Paradigm (like using existing bricks)• Control the chemicals that go into a material, through chemistry• Control of grain sizes, through heating, annealing, etc. MAKE FIND BRICKS DIFFERENT with BAKE WAYS Different BRICKS to cobble them Clays together, to make better structures
  10. 10. New Paradigm (like creating tailored bricks)• Control the patterns in which molecules arrange to form tailor made building blocks of new matter• Control how individual building blocks interact, to create new properties in the matter MAKE SELF-ASSEMBLE USE PRE-EXISTING QUANTUM COMPONENTS METHODS OF DOTS OR COATING, WIRES ASSEMBLE HEATING, WELLS IN-SITU ANNEALING, ETC. OR POLYMERS
  11. 11. What Do We Use Nanomaterials For?• Photodetectors, and solar cells• Light emitters  lasers and lighting• Energy conduits  surface plasmons• Microelectronics• Optical switches• Passive filters  for sensor protection• High strength, low weight composites• High strength cables• Dry lubricant• Temperature resistant applications• Cosmetics
  12. 12. Photodetectors, and solar cells • Bulk material: limited in what proportion of photons it can absorb • Nanocrystals absorb a greater percentage of photons that hit it: solar cells made with nanocrystals to generate more power, for the same area 2X+ X Percentage Percentage of photonsLIGHT of photons LIGHT Absorbed Absorbed By By Nanoparticles Bulk material tuned to each Wavelength
  13. 13. Photodetectors, and solar cells• Light absorbant nanoparticles on flexible substrates• Can be processed using low cost, low demand manufacturing methods
  14. 14. Light Emitters• Nanoparticles: efficient light emitters, not just efficient absorbers – Not due to blackbody effects – Due to materials’ greater susceptibility to interaction with light.
  15. 15. Energy conduitsDetecting surface plasmons as electrons. Schematic of the devicethat converts surface plasmons into an electric current. It consists of asilver nanowire along which the surface plasmons propagate, and acrossing germanium nanowire, that converts the surface plasmons toelectron-hole pairs. A quantum dot can be used to launch the surfaceplasmons along the nanowire. Figure courtesy: Abram L. Falk.
  16. 16. Slow Light Interaction Enhancer
  17. 17. Microelectronics• Carbon nanotube transistors
  18. 18. Optical SwitchesLaser Beam Path Compare spot sizes, which change as a result of refractive index changes in the test material, owing to changes in beam intensity
  19. 19. Passive filters (Optical Limiting)• Two photon absorption leads to a nonlinear absorption• For protecting cameras, sensors Source: Source: /422-002+D.+Thibault+and+J.+Brock+Big+Time+Line+Project
  20. 20. Passive filters (Optical Limiting)• Quantum dots enhance two photon absorption – due to increased susceptibility (longer interaction with) to interaction with light. Directions of motion of sample, to test various intensities Source:
  21. 21. High Strength, Low Weight CompositesContinuous Carbon Nanotube Reinforced CompositesDOI: 10.1021/
  22. 22. High Strength CablesGeorge Washington Bridge George Washington Bridge Suspension Cable If the steel cables were replaced with carbon or other nanotubes -- Cables made of nanotubes are a lot stronger and lighter than steel cables: • Less amounts of cable would be required for the same job • This would make the bridge lighter, and • Have less material expenditure
  23. 23. Temperature Resistant Applications• Stability of many nanoparticles allows them to be used in applications where bulk material would deteriorate.
  24. 24. Cosmetics• Quantum dots, owing to their high absorption, are used in some sunscreens
  25. 25. Dry Lubricant• Ball bearings about 1 nm in diameter – Bucky Balls Source:
  26. 26. Methods of nanoparticle synthesis• Chemical synthesis, in colloids• Aerosol fabrication• Vapor deposition• Molecular beam epitaxy• Etc.• Why bother? – Nanomaterials behave differently from how they behave in bulk. /gsoe/news/shen-breakthrough.cfm
  27. 27. Conclusion History, and its Making• Ancient peoples used nanotechnology, without knowing it.• We are aware of what we are using, but a lot remains unexplained, and while we will grapple with things we do not know for a long time to come, future generations will say we did remarkable things without knowing how we did it. Stained Glass Church Window Damascus Khukri Damascus-Swords-Product-of-Nanotechnology-40503.shtml 05-14-52/Stained-Glass-Window
  28. 28. Your ContributionHere, at CCNY, there are numerous avenues for pursuing nanomaterials related work:• Synthesis and characterization• Modeling and simulation• Use in constructing novel devices
  29. 29. Questions?Yes, I added this picture after the presentation, but only because I had trouble finding it before.