Transcript A Soft Future?

A Soft Future?
Dr. Paul Meredith
Soft Condensed Matter Physics Group
& Centre for Biophotonics & Laser Science
University of Queensland School of Physical Sciences
www.softsolids.physics.uq.edu.au
Theme
Soft Electronics –
Reality or Pipe-Dream?
Plastic Logic©
Outline
What are “soft-solids” and what is “soft-electronics”?
“The Silicon Age”
“The Soft Age” – a revolution in functional materials and high technology
Nanotechnology – “scale without size”
The best of both worlds – nano-engineering of functional soft solids (nano-bio link)
SCM Physics @ UQ
electrically conducting biomaterials
new synthetic conducting plastics
plastic solar cells
nano-engineering of support structures
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Summary – what can we really expect from the functional soft-solids revolution?
What are “Soft Solids”?
Why “Soft Solids”?
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Soft-solids (polymers especially) are cheap to
manufacture, relatively easy to process, can
have better environmental profiles than “hard
solids”, are mechanically flexible and robust ....
but (until recently) have lacked “functionality”
$$$$$
The Silicon Age (1947 onwards)
IBM Archive©
1947 – the 1st transistor
(Ge point contact)
1948 – the 1st junction
transistor (Ge)
John Bardeen
Walter Brattain
William Shockley
(BELL Labs)
Inorganic Semiconductors
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The basic ingredient for all high technology devices and products
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The advantages
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fast
relatively dependable
versatile
technology is in place – they work!
The disadvantages
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costly
very difficult to process (UHV equipment and photolithography)
some compound SCs have horrible environmental profile (e.g. GaAs)
limited stock of some
delicate & no mechanical flexibility
The “Soft Age” (1977 to ......?)
A revolution in functional materials for high technology?
Sov and Alan MacDairmid
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The 2000 Nobel Prize for Chemistry was awarded for the discovery of
metal-like electrical conductivity in iodine-doped polyacetylene
Prior to this discovery (Shirakawa, Heeger, MacDairmid), it was thought that
organic polymers could not conduct electricity in the solid state
The “Soft Age” was born
The “Soft Age” (1977 to ......?)
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Explosion in “functional” soft-solids research (small molecule and large molecule
organic electronics)
Wild predictions of high tech and low tech applications – soft-solid related material
benefits plus electrical (semiconducting) functionality
IBM, Lucent, Philips, Seiko Epson, HP all have major organic electronics programs
1,888 Transistors!
A thin film conducting
polymer transistor and
“soft-circuitry” – arrays
of these transistors on
a flexible polymer sheet
Plastic Logic©
plastic memory
smart textiles
biosensors
electronic ink
organic solar cells
Light emitting polymer
displays – thin, flexible
screens with 180˚ view
The “Soft Age” (1977 to ......?)
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Ever increasing numbers of organic electronic (soft-electronic) materials
(small and large molecules)
Plus “organic molecular crystals” like the oligo-acenes
Nanotechnology “scale without size”
© www.wag.caltech.edu
© http://www.unibas.ch/phys-meso
Nano-engineering of Functional Soft
Solids
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Many “new” nanotechnologies will contain soft materials
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Nano-biotechnology attempts to nano-engineer biomaterials (DNA
electronics etc.)
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The first realistic nano-engineered soft solids will probably be micro or nano
patterned conducting polymers
© http://www.rhk-tech.com/hall
SCM Physics @ UQ – What are we doing to
help (in a small way) fuel this revolution?
Several programs concerned with understanding and utilising functional
soft solids
Heavy focus on biomaterials as well as synthetic polymers
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2.
3.
4.
electrically conducting biomaterials
new synthetic conducting plastics
plastic solar cells
nano-engineering of support structures
1. A Biomaterial Sensor
A melanin sensor
Photocurrent (microA)
Photoactivity of Thin Film Dopa Melanin
(Electropolymerised): +19V Bias
0.40
Lamp On
0.35
Lamp Off
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0
30
60
90
120 150 180 210 240 270 300 330
Time (s)
2. Novel Routes to Synthetic Conducting
Polymers (Ion Implantation)
Sample
Resistivity (Wcm)
Conductivity (S/cm)
PEEK
1.00E+16
1.00E-16
N+ Ion Implanted PEEK
1.02E+06
9.80E-07
Sn+ Ion Implanted PEEK
0.0795
12.58
N+ Ion Implanted PEEK & Sn
0.116
8.62
CHEAP, CONDUCTING PLASTICS –
FROM CONVENTIONAL INSULATING PLASTICS?
Ion Implanted Tin & PEEK
8000
carbon
oxygen
tin & antimony
7000
6000
EDX Scan Line
Counts
5000
4000
3000
2000
50nm
1000
0
0
20
40
60
80
Line Position (nm)
Patterning Strategies:
-conventional and unconventional nano-lith
-inkjet nano-printing of the metal + implantation with a broad beam
-focused ion-beam writing
100
120
140
160
3. Plastic Solar Cells
Current (A)
Current WORLD RECORD ~5% (PCE)
(c.f. Commercial Silicon cells ~ 15%)
3.5x10
-7
2.5x10
-7
1.5x10
-7
0.5x10
-7
-0.5x10
-1.5x10
-7 0
1
2
-7
Voltage (V)
This cell produces a WHOPPING 20mA
nano-crystals in a
conducting polymer
matrix
4. Nano-engineering of Support Structures
– scale without size!
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Create support structures and electrodes which have a very large internal
surface area (nano-engineering) – provide a large surface for attachment of
functional organic molecules and enhance properties such as charge
transport and photon capture
R. Vogel
K. Teo, U. Camb
A carbon nanotube field –
potential solar cell material
R6G/titania nanocomposite formed
into a micro-donut
(microphotonics)
A nanostructured titania support/electrode
Summary – what can we really expect from
the “soft-electronics” revolution?
Timeframe
Product
Comments
NOW
small flat screen displays
phones and digital cameras
1-5yrs
large flat screen displays
disposable soft circuitry (TFTs)
laptops and TV’s
low tech applications & low
speed applications
biological and environmental
sensors
5-10yrs
>10yrs
soft-solid memory
general low & high performance circuitry
soft-solid lasers
soft-solid photovoltaics & optoelectronics
computers & general electronics
general consumer products
low power applications and
throw away sources
paint-on solar cells
soft-solid “nano-electronics”
polymer “spin-tronics”
requires significant advances in
processing and fundamentals
We at UQ Physics are trying to do our bit:
- functional biomaterials
- plastic solar cells
- new (cheap), patternable synthetic conducting polymers
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E. Moore (UQ Postdoc)
D. Blake (UQ / CSIRO PhD)
M. Harvey (UQ PhD)*
J. Riesz (UQ Hons)
S. Subianto (QUT PhD)****
E. Tavenner (UQ PhD)
L. Tran (UQ Postdoc)**
R. Vogel (UQ PhD Chem / Postdoc)*
A. Watt (UQ PhD)*
Acknowledgements
H. Rubinsztein-Dunlop (CBLS)*
P. Bernhardt (UQ Chem)
P. Evans (ANSTO, Lucas Heights)
A. Hamilton (UNSW)
M. Lu (UQ Chem Eng)***
A. Micolich (UNSW)
R. McKenzie (UQ)**
B. Powell (UQ)***
B. Reguse (CSIRO, TIP)
T. Sarna (Jagiellonian University, Poland)
K. Teo (Cambridge University, UK)
G. Wills (QUT)****
Funding:
ARC Discovery (DP0210458, DP0345309)
ARC Linkage (LE0239044)
UQ (ECR, RIBG, RDGS, NSSF)
ANSTO (2002 & 2003)
Procter & Gamble
Centre for Biophotonics &
Laser Science
The End
“For a successful technology, reality must take precedence over public
relations,
for Nature cannot be fooled”
Dick Feynman