What We Do In My Lab
Post on 17-Jan-2015
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What we do in my labOptical Materials
Source: www.nanotech-now.com/current-uses.htm
Source: stm.lbl.gov/Salmeron_group/homeold.html
Source: www.godunov.com/bucky/fullerene.html
Source: www.aip.org/png/2003/186.htm
Source: web.gc.cuny.edu/dept/engineering/
Faissal
Source: scienceblogs.com/.../04/pining_for_the_sun.php
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We want to make
• Optical Protection– For protection from lasers
• Solar Cells– For making electricity
Source: www.howstuffworks.com/solar-cell.htm
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What we do:
• We make nano sized crystals, called quantum dots
• We connect them with carbon nanotubes, which act as wires
• We make plastic films which hold our quantum dots and carbon nanotubes
• We test our films as optical protection, and as solar cells
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We start with crystals
Source: www.faeriesfinest.com/B947.html Source: commons.wikimedia.org/wiki/File:Rock_salt_crystal.jpg
Crystals can look like this:
The crystals that we make are nanometers in size!We call these nanocrystals Quantum Dots.
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How small is a nanometer?
• How small is small?
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We take Atoms from Salts to make our Quantum Dots
CadmiumFrom Salt
SeleniumFrom Salt
Cadmium Selenide(CdSe)
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Our Quantum Dots look like this:
In the Laboratory:We cannot see our Quantum Dots.Here are the models of our nanocrystals
Source: Published online: 25 January 2004; doi:10.1038/nmat1056
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Our crystals are so small, they need protection, so they do not get destroyed
• They are protected by chemicals that are like soap, which cover the crystals
Source: Pileni, Marie-Paule, Nature Materials 2, 145–150 (2003)
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Quantum Dots are Interesting:Smaller dots look BLUE, and larger dots look RED,
under ultra violet light:
Source: www.nanotech-now.com/current-uses.htm
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We also work with Carbon Nanotubes
Source: Mat. Res. [online]. 2008, vol.11, n.3 [cited 2009-07-15], pp. 325-333
Carbon Nanotubes in the Lab Carbon Nanotube Model
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Buckyballs!
The idea for carbon nanotubes came from balls made of carbon atoms: these balls were called Buckyballs!
Source: www.godunov.com/bucky/fullerene.html
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Carbon nanotubes look like this:
Source: www.aip.org/png/2003/186.htm
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We make nanocomposites
Source: www.nanotech-now.com/current-uses.htm
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We make thin films of plastic, with quantum dots and carbon nanotubes in them
• This is our machine for making thin films:– It spins coatings of films, one layer at a time
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We test our films using a LASER
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Source: http://www.rp-photonics.com/lasers.html
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We move our films through a focused laser to see how their properties change
Source: www.microscopy-uk.org.uk/primer/geomop.htm
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We measure changes in:
Source: http://www.sciencebuddies.org/science-fair-projects/project_ideas/Phys_p028.shtml
Refractive Index:
Source: http://www.tcd.ie/Physics/opticslab/facilities/z_scan.php
Absorption coefficient(using two photon absorption):
Source: http://www.hyperzoid.com/csc492/microscopy.html
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A little bit about light
The Electromagnetic Spectrum:
Source: http://www.onpointlasers.com/laser-basics
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Getting Light from an Atom
Source: https://reich-chemistry.wikispaces.com/422-002+D.+Thibault+and+J.+Brock+Big+Time+Line+Project
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Hydrogen Spectra
Source: http://www.goiit.com/posts/list/community-shelf-the-bohr-atom-917720.htm
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A little bit about LASERS
Source: http://www.phy.cuhk.edu.hk/phyworld/articles/laser/laser_e.html
Electron transitions in an atom:
Schematic Diagram of a Ruby Laser:
Comparing laser andordinary lamplight:
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To recap, this is what we do:
• We make nano sized crystals, called quantum dots
• We connect them with carbon nanotubes, which act as wires
• We make plastic films which hold our quantum dots and carbon nanotubes
• We test our films as optical protection, and as solar cells
• You can see other pictures from my lab here:http://www.flickr.com/photos/faissal_bd/sets/72157621760317409/
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