rocess induced morphology changes during drying of thin ... · tft coating and printing lab at...

KIT – The cooperation of Forschungszentrum Karlsruhe GmbH and Universität Karlsruhe (TH)

INSTITUTE OF THERMAL PROCESS ENGINEERING – THIN FILM TECHNOLOGY

Process induced morphology changes during drying of thin films for coated and printed electronics

Michael Baunach, K. Peters, B. Schmidt-Hansberg, L. Wengeler, Philip Scharfer, Wilhelm Schabel

TFT – Group

Benjamin Schmidt-Hansberg

WilhelmSchabel

(Shared Professor)

PhilipScharfer

(Head of TFT @ KIT-CN)

JoachimKrenn

YingZhou

LukasWengeler Katharina

Peters

SibylleKachel

Michael Baunach

Philipp Cavadini

Sandra Jeck

(Joint Project)

2 Michael Baunach - UK-German Partnering Workshop: Process technology for

organic and hybrid solar cells.

Thin Film Technology - Research Fields - Examples

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Organic (Semi-) Conducting Films

Organic Photovoltaic (OPV), Organic LEDs,

Hybrid Solar Cells, Organic Sensors, …

© PHILIPS © Konarka

Source: HOLST CENTER

Fraunhofer ICT

Source: ROCHE

Source: FLEXIBLE DISPLAY CENTER

SOURCE: SZ,

E-Paper

© CEFOTECH

Bioactive Films

Biosensors, Diagnostics, Patches

Biocomps, Medical coatings, …

Foils, Membranes

Optical Films & Foils,

Membranes, Ceramic Foils,

Battery, and Electrode Coatings

Functional Films and Coatings

(Smart-) Coatings, Paints,

Antireflective-, Protective Films, …

Source: ILFORDSource: BAYER

Michael Baunach - Process induced morphology changes during drying of thin

films for coated and printed electronics

http://www.spiegel.de/fotostrecke/fotostrecke-50410-2.html

http://www.spiegel.de/fotostrecke/fotostrecke-50410-3.html

http://images.google.de/imgres?imgurl=http://www.diarc.fi/images/DIARC_Funktio.jpg&imgrefurl=http://www.diarc.fi/functional.html&h=185&w=191&sz=4&hl=de&start=18&tbnid=-nRLEXaNAIjGYM:&tbnh=100&tbnw=103&prev=/images%3Fq%3Dfunctional%2Bcoatings%26gbv%3D2%26hl%3Dde%26sa%3DG

TFT coating and printing lab at „KIT-Hightech-Inkubator“



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Processing of coated and printed electronics

5 Michael Baunach - Process induced morphology changes during drying of thin


Challenges: OPV-Processing and Upscaling



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Sources: 1:(Park et al., 2009), 2: (Dennler, Scharber und Brabec 2009),

3: (Chang et al., 2009), 4: (Kim et al., 2007), 5: (Hoth et al., 2007) ,

6: (Hoth et al., 2009), 7: (Ding et al., 2009),8: (Krebs2, 2009), 9: (Krebs1, 2009).

Coating method Materials Substrate Conditions Electrode R2R PCE Date Ref

Spin Coating PCDTBT/PC70BM Glas Inert ITO NO 6% 2009 1

Spin Coating P3HT/PCBM Glas Inert ITO NO 5% 2009 2

Doctor blade P3HT/PCBM Glas Inert ITO NO >4% 2009 3

Brush painting P3HT/PCBM Glas Inert ITO NO >5% 2007 4

Ink Jet P3HT/PCBM Glas Inert ITO NO 3.5% 2009 5

Spray P3HT/PCBM Glas Inert ITO NO >2,5% 2007 6

Gravure P3HT/PCBM PC Inert ITO NO 1.68% 2009 7

Screen/ Blade /Slot Die P3MHOCT PET Ambient ITO YES 0.84% 2009 8

Slot Die /Screen P3HT/PCBM PEN Ambient ZnOx PDOT YES 0.3% 2009 9

L. Wengeler et al. presented at European Coating Symposium 2009, Karlsruhe

Lab

Pilot

WR for OPV (10/2009): 7.6% PCE

Literature overview

LTI - Lab: ~ 5 % PCE

TFT - Lab (12/2009): 1,6 % PCE

Coating Technology: Pre-metered and Self-metered



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Slot Bead

Slide Curtain

Slot Curtain Source ROTARY COATERSource TSE TROLLER

TFT Lab

TFT Lab

TFT Lab

Roll to Roll (R2R) – coating and drying pilot plant

Roll to Roll:

- Web speed: 0.2 … 20 m/min

- Coating width: 40 … 400 mm

- Dryer length: 2 … 5 m



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Pre-metered

Coating station:

Slot Die/ Slide/ Curtain

Drying channel for defined drying conditions

Raman-Spectroscopy

Gravimetric Measerment

Monochromatic Reflectometry



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100% Solvent

100% Polymer 100% Fullerenez P

olym

er

zFullerene

zSo

lvent

Solubility Limit = f(T)

Solv

ent e

vap

ora

tion

Morphology - drying kinetic – phase separation

Drying kinetics Phase behavior

during drying

Schmidt-Hansberg et al. (2008)

10 Michael Baunach - Process induced morphology changes during drying of thin


OPV-Processing: Influence of drying kinetics

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Fast

Drying

<20 sec

Slow

Drying

>20 min

Drying kinetics

determine solar cell

efficiency!

P3HT:PCBM (1:0.9)

before annealing

B. Schmidt-Hansberg, H. Do, A. Colsmann, U. Lemmer,

W. Schabel, Eur. Phys. J.- ST, 2009, 166, 49-53

G. Li et al., Nature Mater. 4 (2005)



In Cooperation with LTI - KIT

(U. Lemmer)

DFG-SPP: JOINT PROPOSAL (Lemmer, Schabel, Ahlswede, Barrena, Höger)

OPV-Processing: Impact of drying conditions on film

topography

Michael Baunach - UK-German Partnering Workshop: Process technology for

organic and hybrid solar cells.

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AFM scan size 1µm x 1µmGrowing structure size

B. Schmidt-Hansberg, et al., Journal of Applied Physics (accepted)

Same drying time!

OPV-Processing: Simultaneous in situ Reflectometry and

GIXD

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P3HT Crystal

M. Sanyal, B. Schmidt-Hansberg et al., (submitted)

Monitoring at the same time:

- Drying kinetics (thickness, solvent fraction)

- Crystallization (kinetics of crystallization, orientation, phase transitions)



Influence of process steps “coating” and “drying“ on

electrode (anode) morphology

Characterization of electrode: BET, AFM, SEM/TEM, XRD, …

Modelling of process



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Drying experiment with cathode material



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→ Kinetic and thermodynamic properties are dominating the drying process.

Cathode material (IMF III):

LiFePO4 + polymeric binder

+ N-Methyl-2-pyrrolidon (NMP)

In cooperation

W. Bauer (KIT-IMF III)



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Thank you very much for

your attention!

Institute of Thermal Process EngineeringThin Film Technology

rocess induced morphology changes during drying of thin ... · tft coating and printing lab at...

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