what we do in my lab

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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/