Characterization Techniques

in Nanoscale

Selçuk Yerci

Feb 18, 2014

Electronic transition in atoms

2

Electronic, vibrational and rotational resonance

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What is resonance? Why is it important?

• http://www.youtube.com/watch?v=VvUcv6qchpo

• http://www.youtube.com/watch?v=I4FPK1oKddQ

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What do we want to detect?

• Elemental information (what elements are present)

• Chemical bonding

• Imaging

• Physical properties such as thickness and density

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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

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Analytical spot size vs. detection range

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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)

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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

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