Institute of Nanostructured Materials and Photonics

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• Institute of Nanostructured Materials and
  Photonics

3RD WORKSHOP OF THE JOANNEUM RESEARCH AND THE
JOŽEF STEFAN INSTITUTE Ljubljana, September 18,
2006 Georg Jakopic
nmp_at_joanneum.at www.joanneum.at/nmp Franz-Pichler-
Strasse 30, A-8160 Weiz, Austria
ISO 9001 certificated
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NMP mission divisions
Founded in 1999 (Prof.Günther Leising Prof.
Walter Papousek) Head of Institute Prof. Günther
Leising
Aim Applied research on the application of
organic and organic- inorganic nanostructured
systems and photonic systems for new
electronical, optical and optoelectronical
devices
Nanostructuredorganic Systems Division
Head Dr. B. STADLOBER
Optical and dielectric Properties of
nanostructured Materials Division Head Dr. A.
HAASE
Optical andand electronical Properties of
Nanolayers Division Head Mag. A. Rudorfer
Photophysics and Photonics Division Head Dr.
V. SCHMIDT
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NMP teams
Ink-Jet- Team
Integrated Electronics-Team
LED-Lab
Nano-Im-print-Litho-graphie-T.
3D-TPA- Team
Optical Simulations-Team
Opto-Electronics-Team
RUDORFER Andreas, Mag.
PALFINGER Christian, Dr.
STADLOBER Barbara, Dr.
WENZL Franz-Peter, Dr.
SCHMIDT Volker, Dr.
SOMMER Christian, Dr.
LAMPRECHT Bernhard, Dr.
PICHLER Heinz, Mag.
HAAS Ursula, Mag.
HAAS Ursula, Mag.
SOMMER Christian, Dr.
KUNA Ladislav, Dr.
SCHMIDT Volker, Dr.
KRAKER Elke, Mag.
SCHOEN Helmut, DI
GOLD Herbert, Dr.
HAASE Anja, Dr.
SATZINGER Valentin, Mag.
LAMPRECHT Bernhard, Dr.
JAKOPIC Georg, Dr.
GOLD Herbert, Dr.
PALFINGER Christian, Dr.
N A N O A N A L Y T I C S
ZINTERL Ernst, Mag.
ZIRKL Martin, Mag.
ELLIPSOMETRY JAKOPIC Georg, Dr.
XPS - UPS FIAN Alexander, DI
UV-VIS-NIR-Spectroscopy SOMMER Christian, Dr.
JAKOPIC Georg, Dr.
SCHOEN Helmut, DI
LUMINESCENCE WENZL Franz-Peter, Dr.
OPTICAL MICROSCOPY SATZINGER Valentin, Mag.
AFM HAASE Anja, Dr.
SEM GOLD Herbert, Dr.
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Organic Solids
Nanotechnology
Lab-samples
Materials
Processes
Products
Polyapply
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Introduction to pentacene
Organic Electronics (1)

• Small molecule, organic, p-type semiconductor
• Thin films by high vacuum deposition
• Well-ordered molecules in herringbone structure
• Polycrystalline structure and grain quality
  depend
• on a set of deposition parameters

Pentacene molecule C22H14
Pentacene on SiO2 (thermally evaporated in high
vacuum), 4.8 nm. a) AFM height signal, b) step
height measurement
Pentacene polymorphism XRD-measure-ments thin
film phase c-axis-length 1.54 nm
B
A
3 µm
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Organic Electronics (2)
Grain size dependence of charge carrier mobility
for pentacene (50nm) on SiO2 (Vgs -30V)
channel resistance dominated by
intra-grain mobility
grain boundaries
A. Di Carlo, A. Bolognesi, F. Piacenza, B.
Stadlober, H. Maresch, APL 87 (2005), in print
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Organic Electronics (3)Surface dynamic processes
during condensation
see also J.A. Venables et al., Rep.Prog.Phys.
47, 399 1984
Condensation R
Re-evaporation
Ed surface diffusion barrier Ej binding
energy of a molecule in a cluster of j
molecules Ei nucleation barrier R deposition
rate Ea desorption energy of a molecule
Surface diffusion
Ea
Adsorption
Ej,i
Ed
Special sites (defects,...)
Binding, nucleation
Surface diffusion
Interdiffusion
Rate equation theory N ? RpeE
Condensation regimes for 2d-growth
N island density R deposition rate p
growth-determining exponent E total energy of
system i critical nucleus size
Regime p,E for 2d-growth p(i1) p(i2) p(i3)
Extreme incomplete p i E ? Ei(i1)Ea-Ed 1 2 3
Initially incomplete (most cases) p i/2 E ½ (EiiEa) 0.5 1 1.5
Complete (Ea0, no re-evaporation) p i/(i2) E ? (EiiEd)/(i2) 0.33 0.5 0.6
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Organic Electronics (4)Pentacene submonolayers
on different substrates 0.3nm
Deposition rate 0.1 nm/min

• Correlated 2d island growth
• Similar growth dynamics for PVP and SiO2
• Highest coverage at RT
• Lowest coverage at 60C
• Largest grain size at 65C
• Grain size at 65C
• SiO2 gt PVP gt PMMA PVCi
• Surface roughness
• SiO2 lt PVP lt PMMA PVCí

10 µm
PVP poly(vinylphenol) PMMA poly(methylmethacry
late) PVCi poly(vinylcinnamate)
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Soft Lithography (1)
Embossing
Printing
Molding
Hard Stamps
SOFT Stamps (Soft Lithography)
Soft Stamps (Soft Lithography)
Soft Stamps (Soft Lithography)
Solvent AssistedMicromolding
Replica Molding
Micro-Contact Printing
Nano Imprinting
Liquid Embossing
Micromolding In Capillaries
Flash(UV curable Polymer)
Soft Embossing
Microtransfer Molding
Thermo- setting Polymer
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Soft Lithography (2)
Hot-Embosser
UV-Imprinter/Mask-Aligner
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Soft Lithography (3)
oFET-process
imprint resist
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5
substrate
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12
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Au (e-beam evaporation)
Al-gate (evaporation through shadow-mask)
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heating
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stamp (Si), aligned in EVG 620
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lift-off with e.g. acetone
organic dielectric (spin-coating)
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pressure (EVG 520)
residual etch (RIE)
pentacene (thermal evaporation)
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11
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heating
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Soft Lithography (4)
oFET structures
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Soft Lithography (5)improved oFET- and other
structures
long conductor paths
comb-structure
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3d-TPA-Nano-Lithography (1)
2 photon process
Excited state
Most resins that polymerize upon UV exposure can
also polymerize upon simultaneous absorption of
two photons of double wavelength prerequsite
sufficient laser power
1 photon process
Ground state
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3d-TPA-Nano-Lithography (2)
Laser ablation vs. Multiphoton absorption
3D scanning of laser focus across volume
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3d-TPA-Nano-Lithography (3)
Shutter/Attenuator
Stage
Ultrafast TiS Laser
Machine Vision
Beam Analysis
PC Control and CAD
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3d-TPA-Nano-Lithography (4)
model
contour slicing
coordinates
For same exposure conditions Material properties
are important for results
Not optimized TPA starter
Optimized TPA starter
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3d-TPA-Nano-Lithography (5)
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LED - color conversion
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Photoelectronspectroscopy
Ellipsometry
Scanning tunneling microscopy
Atomic force microscopy
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THANK YOU FOR YOUR ATTENTION !
nmp_at_joanneum.at www.joanneum.at/nmp Franz-Pichler-
Strasse 30, A-8160 Weiz, Austria
ISO 9001 certificated