Date post: | 21-Dec-2015 |
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Exploration of Nanoparticles
Steven Hershmanunder
Dr. Chris MurrayDepartment of Chemistry
Contents
• Introduction to nanoparticles?
• How do you make large nanostructures?
• How can computers aid in research?
• Summary
Contents
• Introduction to nanoparticles?
Nanoparticles
• Particles < 100 nm
• Quantum Confinement– 1st approximation:
http://cats.about.com/od/catpictures/ig/ContainerCats/pippinbox400x533.htm
Band Theory
Bandgap for Quantum Dot
Interesting Nanoparticle properties
• Quantized energy levels
• Tunable bandgap
• Tunable Optics
• Coulomb blockade
• Other cool stuff!
Tunable bandgap
Particle-in-a-Box
Like term for Quantum Confinement
Electrostatic attraction between valance and conductance band
Tunable optics
http://content.answers.com/main/content/wp/en/thumb/6/69/395px-Fluorescence_in_various_sized_CdSe_quantum_dots.png
Coulomb blockade
• Energy to add an electron:
< kT it can’t spontaneously happen!
Single electron transistor
Capacitance of spherical particle
Other Cool Stuff!
• Multiple carrier excitation– Next generation solar cells
• Nonlinear optics– Goodbye Beer’s law– Applications
• Change light intensity• Change wavelength• Faster optical switches
Contents
• How do you make large nanostructures?
A DNA analogy
Generating a synthetic genome by whole genome assembly: X174 bacteriophage from synthetic oligonucleotides
Oriented attachment
• Ligation for nanoparticles
R. Lee Penn and Jillian F. Banfield "Imperfect Oriented Attachment: Dislocation Generation in Defect-Free Nanocrystals" Science 281 (5379) : 969-971. (1998) (in Reports)
Contents
• How can computers aid in research?
Modeling Exotic-Shaped Nanoparticles
Quickly apply theory
WAXD
0
500000
1000000
1500000
2000000
2500000
3000000
10 20 30 40 50 60 70 80 90 100 110 120 130
2theta
I
And try to match it with experiment…
But lab is still being constructed
Thanks:
•Dr. Chris Murray
•Dr. Doug Yates
•Christine Eklund
•Roy Vagelos