D.S.H. Charrier
20
D.S.H. Charrier Dimitri S.H. Charrier
description
L ong term project. PEDOT:PSS. Process partially explained…. O rganic actuator and memory based on PEDOT:PSS. Dimitri S.H. Charrier. D.S.H. Charrier. L ong term project. PEDOT:PSS. Process partially explained…. 1. 2. 3. Long term project. SKPM potentiometry. STM potentiometry. - PowerPoint PPT Presentation
Transcript of D.S.H. Charrier
D.S.H. Charrier
Dimitri S.H. Charrier
D.S.H. Charrier
1 Long term project.•SKPM potentiometry.•STM potentiometry.•A detour…
PEDOT:PSS.•Giant actuation.•Memory.
Process partially explained…•Drying effect.•Sorbitol.
2
3
} on high performance organics
D.S.H. Charrier
1 Long term project.•SKPM potentiometry.•STM potentiometry.•A detour...
PEDOT:PSS.•Giant actuation.•Memory.
Process partially explained…•Drying effect.•Sorbitol.
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D.S.H. Charrier
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surf
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patterned in clean room
simulated with COMSOL and MatLab
dielectric
source
gate
tip
drain
active layer
lever
Our results on test devices
L. Bürgi et al, Synthetic Metals, 146, 297 (2004)
P3HTT = 165 K
D. Charrier et al, submitted
D.S.H. Charrier
electronic control
UHVchamber
STM head
Home built
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before field after field
Typical polymer used for organic actuation, polypyrrole = PPy.Largest Strain (elongation) = 36.7 %Redox reactions involveld, PPy↔PPy+.Anionic counter ions to maintain charge neutrality.
A huge height increase = 230 nm
PEDOT:PSS as active layer(thickness: 60-70 nm)
S. Hara et al, Synthetic Metals, 156, 351 (2006)
PEDOT
PSS
D.S.H. Charrier
1 Long term project.•SKPM potentiometry.•STM potentiometry.•A detour...
PEDOT:PSS.•Giant actuation.•Memory.
Process partially explained…•Drying effect.•Sorbitol.
2
3
D.S.H. Charrier
-5 0 5 10 15 20 25 30 35 40
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SiO2
AuAu
saturation
+-
Before field (pristine) After field
Initial thickness of PEDOT:PSS = 60-80 nmSpin-coated on glass or on SiO2
A height increase of about 400% !!!
D.S.H. Charrier
0 20 40 60 80 100 1200
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+ 3.7 0 - 3.7 V
Reversible…
D.S.H. Charrier
-2 0 2 4 6 8 10 12 14 16 18 20 22
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aver
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Reversible cycles > 12
Switching the bias +/- 4 V
Reversible height increase of about 50%
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zoom
D.S.H. Charrier
U (V) t (s) U (V) t (s) U (V) t (s) U (V) t (s) I off (A) I on (A)1 4 30 0.5 10 -4 30 0.5 10 2.93E-08 2.45E-08 8.35E-012 4 60 0.5 10 -4 60 0.5 10 3.86E-09 1.60E-08 4.14E+003 3.5 30 0.5 10 -3.5 3 0.5 10 1.22E-09 3.65E-09 3.01E+004 4 30 0.5 10 -4 4 0.5 10 2.69E-09 6.60E-09 2.46E+005 3.5 60 0.5 10 -3.5 10 0.5 10 5.38E-10 6.07E-09 1.13E+016 3.5 90 0.5 10 -3.5 20 0.5 10 1.51E-11 7.06E-09 4.66E+027 4 30 0.5 10 -4 30 0.5 10 3.87E-10 8.77E-09 2.26E+018 4 3 0.5 1 -4 3 0.5 1 -3.27E-09 1.64E-08 -5.00E+009 4 3 0.1 0.4 -4 3 0.1 0,4 -2.27E-08 2.54E-08 -1.12E+00
readwrite On/OffOn/Off ratioreaderase
Best ratio we gotOn/Off = 466
Optimal organic memoryOn/Off > 10 000
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Hint: electrochemical alteration?
0 1 2 3 4-0.50.00.51.01.52.02.53.03.54.0
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D.S.H. Charrier
1 Long term project.•SKPM potentiometry.•STM potentiometry.•A detour...
PEDOT:PSS.•Giant actuation.•Memory.
Process partially explained…•Drying effect.•Sorbitol.
2
3
D.S.H. Charrier
PEDOT:PSS is hygroscopic…
•At 40-60 % of H20 in air, motion for > 3.5 V•At 20 % motion for > 50 V•At 13 % no motion visible
‘dry’
‘wet’
2 remarks:•2 bumps at around +/-2 V•Indication for ionic current
-10 -8 -6 -4 -2 0 2 4 6 8 10-800.0
-600.0
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‘wet’
‘dry’
D.S.H. Charrier
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before after
thickness = 90-100 nm
+- -
sorbitol+anneal: more compact morphology.
(sub)conclusion:
Other actuation mechanism-5 0 5 10 15 20 25 30 35 40
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D.S.H. Charrier
At positive electrode 2 reactions may occur:
PEDOT + PSS- → PEDOT+(PSS-) + e- (1)
•Charge neutrality requires movement of PSS- to + electrode.•Large volume increase at + electrode•Requires mobile PSS (‘large size’)…
PEDOT(PSS Na) → PEDOT+(PSS-) + Na+ + e- (2)
•Charge neutrality requires movement of Na+ away from + electrode.•Smaller volume change, sign can be + or -•Requires mobile Na (‘small size’)
Adapted from: Elisabeth Smela, Adv. Mater. 2003, 15, 481. (Review)
‘Wet’
‘Dry’‘Sorbitol’
D.S.H. Charrier
all images: 500 500 nm2, z = 20 nm, done by Alex Nardes
anneal at 200C
kBT ~ 40 meV
F Lchar = (4 V/4m) 40 nm ~ 40 meV
(voltage/channel length ~particle size)
Can the field move any material?
D.S.H. Charrier
Color changing ?
Before field After/during field
+-
Electrochromic devices
Electrochemical reaction at + electrodeor
PEDOT+ moving to anode…?
‘bluish’
Sorbitol case‘brownish’
D.S.H. Charrier
Reaction ?
www.baytron.com
PEDOT to + ?
?
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•Prediction of SKPM response via 3D modeling•STM as alternative to SKPM: in progress
•Giant actuation based on PEDOT:PSS•Organic memory based on PEDOT:PSS encouraging
•Actuation partially explained by ionic current and mass transport•Activation energy explains the motion•Optical changes visible
PEDOT + PSS- → PEDOT+(PSS-) + e-
PEDOT(PSS Na) → PEDOT+(PSS-) + Na+ + e-
D.S.H. Charrier
M2N / TU/e
Lukáš BřínekMartijn KemerinkAlex NardesRené JanssenGérard Wijers
OED / TU/e
Barry SmalbruggeTjibbe de Vries
