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Characterization Techniques
in Nanoscale
Selçuk Yerci
Feb 18, 2014
Electronic transition in atoms
2
Electronic, vibrational and rotational resonance
3
What is resonance? Why is it important?
• http://www.youtube.com/watch?v=VvUcv6qchpo
• http://www.youtube.com/watch?v=I4FPK1oKddQ
4
What do we want to detect?
• Elemental information (what elements are present)
• Chemical bonding
• Imaging
• Physical properties such as thickness and density
5
Excitation sources
• Light
• Electron
• Ion
• Heat
• Chemical Reaction
• Magnetic field + light
• Reflection, transmission
and refraction
• Absorption
– Beer’s law (e-ad)
• Luminescence
– Photo-, electro-, thermo,
cathodo-, chemi-
• Scattering
– Diffraction
– Raman
Physical phenomena
Detection
• Light
• Electron
• Ion
• …
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Optical diffraction
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X-ray diffraction
!
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Raman spectroscopy
Segregation of Ge and Si in
Si- and Ge-rich SiO2 matrix
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What is the advantage of electron excitation?
Heavier and faster shorter wavelength
10
Analytical spot size vs. detection range
11
Typical analysis depth for techniques
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Categories of Materials Characterization
Techniques
• Imaging
• Structural properties
• Chemical properties
• Elemental analysis
• Surface properties
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Image Analysis
• Optical microscopy
• SEM/EDX – Scanning Electron Microscopy with
Energy Dispersive X-Ray detector
• SPM – Scanning Probe Microscopy
• AFM – Atomic Force Microscopy
• TEM – Transmission Electron Microscopy
Ag back reflector
1μm
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Surface Analysis
• AES – Auger Electron Spectroscopy
• XPS – X-Ray Photoelectron Spectroscopy
• TOF-SIMS – Time of Flight Static Secondary Ion
Mass Spectroscopy
• LEED – Low Energy Electron Diffraction
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Structural Analysis
• XRD – X-Ray Diffraction
• XAX/EXAFS - X-ray Absorption Spectroscopy and
Extended X-Ray Absorption Fine Structure
• Raman spectroscopy
• TEM/EDX – Transmission Electron Microscopy
• EELS – Electron Energy Loss Spectroscopy
(typically combined with TEM)
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Chemical Analysis
• FTIR – Fourier Transform Infrared Spectroscopy
• GC/MS – Gas Chromatography with Mass
Spectroscopy (detector)
• HPLC – High Performance Liquid Chromatography
• Raman spectroscopy (structural organic)
17
Elemental Analysis
• ICP – Inductively Coupled Plasma
• XRF – X-Ray Fluorescence
• PIXE - Particle-Induced X-ray Emission
• Optical atomic spectroscopy
• X-ray photoelectron spectroscopy
• Secondary ion mass spectroscopy
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Electron matter interaction
When a solid material is bombarded
with an electron beam several
particles are emitted as a result of
energy and momentum transfer
Energy of emitted electrons after the
bombardment of an electron beam
with an energy of Eo
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Scanning Electron Microscopy (SEM)
(a)
1 µm
(b)
4 µm
(c)
20 µm
(d)
40 µm
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2000C
5000C 4000C
3000C
500 nm 500 nm
500 nm 500 nm 400 600 800 10000,0
0,2
0,4
0,6
0,8
1,0
1,2
no
rma
lize
d r
efle
ctivity
wavelength (nm)
2000C
3000C
4000C
5000C
Plasmonic reflection from the Ag
nanoparticles
500 nm
SEM images of Ag Nanoparticles on ITO
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Before annealing After annealing
100 nm
Si nanowires
Example Images
22
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