SELF-ORGANIZED THIAZOLO[5,4-d]THIAZOLE-BASED LIQUID
CRYSTALLINE ORGANIC SEMICONDUCTORS (LCOSCs)
FOR (SUPRA)MOLECULAR (OPTO)ELECTRONIC APPLICATIONS
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
Agnieszka IWAN1, Natalie GRUENKE2-3, Henryk JANECZEK4, Saïd SADKI3 & Patrice RANNOU3*
Calamitic
LCOSC
1
IEL-WROCLAW
Electrotechnical Institute
Division of Electrotechnology & Materials Science
M. Sklodowskiej-Curie Street 55/61, 50-369 WROCLAW (POLAND)
2
DEPARTMENT OF CHEMISTRY
Furman University
3300 Poinseet Highway, GREENVILLE, SC 29613 (USA)
3
UMR5819-SPrAM (CEA/CNRS/Univ. J. FOURIER-GRENOBLE I)
Structures et Propriétés d’Architectures Moléculaires
Institut Nanosciences & Cryogénie (INAC), CEA-Grenoble
17 Rue des Martyrs, F-38 054 GRENOBLE Cedex 9 (FRANCE)
4
CMPW-PAN
Centre of Polymer & Carbon Materials (CMPW)
Polish Academy of Sciences (PAN)
M. Sklodowskiej-Curie Street 34, 41-819 ZABRZE (POLAND)
*E-mail: patrice.rannou@cea.fr
Calamitic
LCOSC
1
OUTLINE
•MOLECULAR vs. SUPRAMOLECULAR vs. ORGANIC (OPTO)ELECTRONICS
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
•STATE OF THE ART PERFORMANCES OF ORGANIC
(OPTO)ELECTRONIC DEVICES
•THIAZOLO[5,4-d]THIAZOLE-BASED OSCs
&CALAMITIC/HEXACATENAR LCOSCs:
SYNTHETIC ROUTE & LIBRARY
Nem*
•THIAZOLO[5,4-d]THIAZOLE-BASED OSCs
& CALAMITIC/HEXACATENAR LCOSCs:
SEC CHARACTERIZATIONS
•THIAZOLO[5,4-d]THIAZOLE-BASED OSCs
& CALAMITIC/HEXACATENAR LCOSCs:
DSC & POM & XRD CHARACTERIZATIONS
•THIAZOLO[5,4-d]THIAZOLE-BASED OSCs
& CALAMITIC/HEXACATENAR LCOSCs:
UV-Vis & PL CHARACTERIZATIONS
•THIAZOLO[5,4-d]THIAZOLE-BASED OSCs
& CALAMITIC/HEXACATENAR LCOSCs:
CV & DPV CHARACTERIZATIONS
•CONCLUSIONS, ONGOING/FUTURE STUDIES & ACKNOWLEDMENTS
2
MOLECULAR vs. SUPRAMOLECULAR vs. ORGANIC
(OPTO)ELECTRONICS
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
MOLECULAR
(OPTO)ELECTRONICS
SUPRAMOLECULAR
(OPTO)ELECTRONICS
ORGANIC
(OPTO)ELECTRONICS
~1-5nm
~5->100nm
~100nm->20µ
µm
SINGLE MOLECULES
π-CONJUGATED
MOLECULAR WIRES
(OLIGOMERS)
BOTTUM UP
APPROACH
Nature 408, 541 (2000).
Science 300, 1384 (2003).
Nat. Nanotech. 1, 173 (2006).
Acc. Chem. Res. 41, 1731 (2008).
Angew. Chem. Int. Ed. 48, 3911 (2009).
THIN FILMS/SINGLE CRYSTAL
SELF-ORGANIZED &
OF OSCs
HIERARCHIZED OSCs
(MOLECULES,
(MOLECULES, DENDRIMERS,
DENDRIMERS, OLIGOMERS
MACROMOLECULES, LCs
& (CO)-POLYMERS)
& SUPRAMOLECULES)
ADVANCED CMOS
PLATE-FORME
Nature 419, 353 (2002).
Nat. Mater. 3, 507 (2004).
Chem. Commun. 3245 (2005).
TOP DOWN
APPROACH
Nature 428, 911 (2004).
3
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
STATE OF THE ART PERFORMANCES OF ORGANIC (OPTO)ELECTRONIC
DEVICES: OLEDs/PLEDs, SOLAR CELLS, (SC)OFETs/PFETs & LASERS
•OLEDs/PLEDs
•(SC)OFETs/PFETs
40" OLED TV: Prototype 2006
MOLECULAR &
MACROMOLECULAR
π-CONJUGATED
11" OLED TV (XEL-1): Dec. 2007
ARCHITECTURES:
Nature 397, 121 (1999). J.Mater.Chem. 10, 1471 (2000).
Phys.StatusSolidi (a) 201, 1302 (2004). Adv.
Chem.Soc.Rev. 37, 2543 (2008). Chem.Rev. 109, 897 (2009).
Mater. 17, 2411 (2005). Rev.Mod.Phys. 78, 973
FUNCTIONAL
Nature 459, 234 (2009).
(2006). Mater.Today 10, 20 (2007). Adv.Mater.
R-G-B-WHITE OLEDs/PLEDs
19, 1791 (2007). Chem.Rev. 107, 926 (2007).
OSCs
5
-2
Chem.Rev. 107, 1066 (2007). Chem.Rev. 107,
WITH LIFETIME UP TO 10 HOURS @1000 cd.m
WITH
TUNABLE
1296 (2007). Chem.Eur.J. 14, 4766 (2008).
-1
WITH EFFICIENCY UP TO 110 lm.W
Angew.Chem.Int.Ed. 47, 4070 (2008). Adv.
(OPTO)ELECTRONICS Mater. 21, 1473 (2009).
•LIGHT-EMITTING
FEATURES
p-TYPE SCOFETs: µh UP TO ~10-43.0 cm2.V-1.s-1
(SC)OFETs/PFETs
n/p-TYPE OFETs: µh/e- UP TO ~5.0-6.0 cm2.V-1.s-1
Nat.Mater. 5, 605 (2006). Chem.Rev. 107, 1296 (2007). Adv.
+
n-TYPE PFETs:
µe- UP TO ~0.9 cm2.V-1.s-1
Mater. 19, 1791 (2007). Adv.Funct.Mater. 17, 3421 (2007).Adv.
Funct.Mater.19, 1728 (2009). Appl.Phys.Lett. 95, 103307 2009
"WET" / "DRY" p-TYPE PFETs: µh UP TO ~3.0 cm2.V-1.s-1
•SOLAR CELLS
PROCESSING ROUTES •ORGANIC/PLASTIC LASERS
R
EMERGING FIELD OF
ORGANIC/PLASTIC
(OPTO)ELECTRONICS
Adv.Funct.Mater. 11, 15 (2001). Mater.Today 7, 36
(2004). Mater.Today 10, 28 (2007). Mater.Today 10, 34
(2007). Adv.Funct.Mater. 18, 169 (2008). Adv.Mater. 21,
1323 (2009). Adv.Mater. 21, 1434 (2009).
EPCE (UNDER AM1.5) UP TO 6.5%
S.R. Forrest,
"The path to ubiquitous and
low-cost organic electronic
appliances on plastic",
Science 317, 222 (2007). Nat.Photon. 3, 297 (2009)
Nature 428, 911 (2004).
R
R
R
n
LPPP
Rep.Prog.Phys. 63, 729 (2000). Mater.Today
7, 28 (2004). Chem.Rev. 107, 1272 (2007).
J.Mater.Chem. 19, 7520 (2009)
NO REPORT TO DATE OF
AN ELECTRICALLY-DRIVEN
ORGANIC/PLASTIC LASER
4
THIAZOLO[5,4-d]THIAZOLE-BASED OSCs &
CALAMATIC/HEXACATENAR LCOSCs: SYNTHETIC ROUTE & LIBRARY
J. Ephraim, Ber. 94, 1027 (1891).
J.R. Jonhson & R. Ketcham,
J. Am. Chem. Soc. 82, 2719
(1960).
R1
R2
O
C
R3
yield
~15-50%
S
H H2N
C C
NH2
S
dithioxamide
R1
R2
R3
S
N
N
S
R1
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
R2
R3
5
THIAZOLO[5,4-d]THIAZOLE-BASED OSCs &
CALAMATIC/HEXACATENAR LCOSCs: SIZE EXCLUSION
CHROMATOGRAPHY (SEC) CHARACTERIZATIONS
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
SEC Line: HP Chemstation 1100
SEC Column: 300*7.5mm PL-Gel Mixed-D 5µm/104 Å @ 313K
Calibration Curve: 10 PS Narrow Standards (PL: Kit S-M2-10*)
Eluent: THF, Flow Rate: 1ml.min-1, RI & UV-Vis Detection
20 µl Injection
6
THIAZOLO[5,4-d]THIAZOLE-BASED OSCs &CALAMATIC/HEXACATENAR
LCOSCs: DIFFERENTIAL SCANNING CALORIMETRY (DSC), POLARIZED
OPTICAL MICROSCOPY (POM) & XRD CHARACTERIZATIONS
LCTT23-SmC
@ 152.5°C
50µ
µm
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
LCTT23-SmG
@ 140.0°C
50µ
µm
LCTT23-SmF
@ 148.0°C
50µ
µm
LC/LC*
LASERS
LC/LC* LASERS:
TOWARDS APPLICATIONS IN
LC/LC* LASER & COLOR
INFORMATION TECHNOLOGY (CIT)
UPON FURTHER REFINEMENT
OF THE CHEMICAL STRUCTURE
(R1/R2/R3) OF TT-BASED LCOSCs
LCTT21
ISO->Nem @ 201.0°C
Nem->SmC @ 200.0°C
SmC->SmI @ 121.5°C
SmI ->Cr
@ 119.0°C
LCTT21-SmC
@ 125°C
90µ
µm
LCTT21-SmI
@ 120°C
90µ
µm
LCTT31
ISO-> Nem* @ 217.5°C
Nem*->G @ 145.0°C
Nem*
LCTT23
ISO->SmC @ 185.0°C
SmC->SmF @ 150.0°C
SmF->SmG @ 145.0°C
SmG-> Cr @ 51.5°C
R. Won,
Nat.Photon. 2,
593 (2008).
D. Graham-Rowe,
Nat.Photon. 3,
183 (2009).
LC/LC* CIT
N. Tamaoki,
Adv.Mater.
13, 1135
(2001).
LCTT31-Nem*
@ 210°C
25µ
µm
LCTT31-Nem*
@ 200°C
90µ
µm
LCTT31-Nem*
@ 160°C
90µ
µm
LCTT31-Nem*
@ 180°C
90µ
µm
LCTT22
ISO-> SmC @ 222.5°C
SmC ->Cr @ 192.5°C
LCTT24
ISO ->SmA @ 265.0°C
SmA->SmB @ 225.0°C
SmB ->Cr @ 192.5°C
LCTTs: J. Bartulin et al., Mol.Cryst.Liq.Cryst. 180, 297 (1990). Y.Z. Youssif & A.J.A. Hamdani, Liq.Cryst. 15, 451 (1993). 7
THIAZOLO[5,4-d]THIAZOLE-BASED OSCs &
CALAMATIC/HEXACATENAR LCOSCs: UV-VIS ABSORPTION (UV-Vis) &
PHOTOLUMINESCENCE SPECTROSCOPIC (PL) CHARACTERIZATIONS
OPTOELECTRONIC
FEATURES OF TT1:
M.R. Pinto et al. ,
J.Photochem.
Photobiol.A
143, 119 (2001).
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
THIAZOLO[5,4-d]THIAZOLE-BASED OSCs
& CALAMATIC/HEXACATENAR LCOSCs:
TOWARDS
APPLICATIONS
• "HIGH" OPTICAL BANG GAP
IN VIOLET-BLUE
OSCs: ~2.7eV< EgOpt. < ~3.2 eV
LC OLEDs
&
• TUNABLE VIOLET-BLUE EMITTERS BY DESIGN
LC/LC*LASERS
• PL EMISSION TUNING OVER ~22 nm
LC
BY DESIGN & BY APPROPRIATE CHOICE OF
OLEDs
R1/R2/R3 FUNCTIONAL (ACCEPTING OR
DONATING) GROUPS
LC OLEDs: M. O’Neil & S.M. Kelly, Adv.Mater. 39, 4223 (2007).
LC/LC* LASERS: R. Won, Nat.Photon. 2, 593 (2008). D. Graham-Rowe, Nat.Photon. 3, 183 (2009).
LC/LC*
LASERS
8
THIAZOLO[5,4-d]THIAZOLE-BASED OSCs &
CALAMATIC/HEXACATENAR LCOSCs: CYCLIC VOLTAMMETRY (CV) &
DIFFERENTIAL PULSE VOLTAMMETRY (DPV) CHARACTERIZATIONS
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
ELUMO/HOMO [eV]~ -5.1 - Epeak
TOWARDS APPLICATIONS IN LC OLEDs,
LC/LCOFETS & LC SOLAR CELLS UPON
•FURTHER REFINEMENT OF THE CHEMICAL
STRUCTURE (R1/R2/R3) OF TT-BASED LCOSCs
•APPROPRIATE CHOICE OF ELECTRODES
TT1
& OF DONNOR/ACCEPTOR COUPLES
EgOpt.~ 3.16eV
LC
EgElectroch.~ 3.08 eV
OLEDs
CV/DPV: Indirect Estimation of HOMO/LUMO Levels
S. Trasati, Pure&Appl.Chem. 58, 955 (1986). I. Polenc et al., J.Polym.Sci.Polym.Chem.
LC
41, 1034 (2003).
OFETs
UPS/IPES vs. CV/DPV vs. DFT: (In)Direct Estimation of HOMO/LUMO Levels
LC
P.I. Djurovitch et al., Org.Electron. 10, 515 (2009).
SOLAR
CV/DPV Conditions: W.E./C.E.: Pt & Ref. E.: Ag/AgCl vs. Fc+/Fc
-1
-2
-4
CELLS
CV/DPV Scan rates: 100/10mV.s . ~10 -10 M in ACN (0.1 M TBAP).
LC OLEDs: M. O’Neil & S.M. Kelly,
Adv.Mater. 39, 4223 (2007).
LC OFETs: Y. Shimizu et al.,
J.Mater.Chem. 39, 4223 (2007).
LC Solar Cells: L. Schmidt-Mende
et al. Science 293, 1119 (2001).
9
CONCLUSIONS, ONGOING/FUTURE STUDIES & ACKNOWLEDGMENTS
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
CONCLUSIONS
•We have designed, synthesized and characterized a concise library
of Thiazolo[5,4-d]Thiazole (TT)-based molecular Organic SemiConductors
(OSCs) and Liquid Crystals (LCs) consisting of calamitic & hexacatenar
π-conjugated thermotropic functional LCOSCs with an (opto)electronically
active (lath-shaped) TT core.
•The appropriate choices of R1/R2/R3 functional groups of different stiffness,
chemical or electronic natures allow for a rich mesomorphism [Nem,
SmA/B/C/F/G/I and Nem* mesophases] and for tunable on-demand
optoelectronic properties [λ
λmax [nm], λem. [nm], Band Gap Eg [eV], HOMO
and LUMO levels [eV]] of great scope for testing their potentials as [stimuli
responsive: temperature, pH, light …] active layers of new generations of
supramolecular (opto)electronic devices [LEDs, Solar Cells, Lasers & FETs].
Natalie
Gruenke
Agnieszka
Iwan
Saïd
Sadki
Henryk
Janeczek
ACKNOWLEDGEMENTS: FUNDING/SUPPORTS
•Univ. J. FOURIER + FURHMAN Univ. [2009]
•CNRS/PAN [2009-2010] "Project N°22529"
ONGOING & FUTURE STUDIES
• Developing Libraries of p-type & n-type Calamitic/Tetracatenar/Hexacatenar
Thiazolo[5,4-d]Thiazole-based LCOSCs.
•Studying the impact of geometrical/electrical confinements [within operating devices] on
- the mesomorphism & structural organization
- the (opto)electronic features
of Thiazolo[5,4-d]Thiazole-based Calamitic/Tetracatenar/Hexacatenar LCOSCs.
10
CONVENTIONAL OSCs vs. FUNCTIONAL THERMOTROPIC
π-CONJUGATED LC OSCs
"CONVENTIONAL" OSCs
•FIXED "STATIC "
MULTI-SCALE
ORDER/DISORDER
• STRUCTURAL
ORGANIZATIONS
vs.
ELECTRONIC
TRANSPORT
PROPERTIES
RELATIONSHIPS
Nobel Prize in Chemistry 2000!
S.R. Forrest, Nature 428, 911 (2004).
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
FUNCTIONAL THERMOTROPIC π-CONJUGATED LCOSCs
•
TUNABLE (F(T)) &
"DYNAMIC" (LC STATE)
MULTI-SCALE
ORDER/DISORDER
+ SELF-HEALING ABILTY
STRUCTURAL
ORGANIZATIONS
vs.
ELECTRONIC TRANSPORT
PROPERTIES RELATIONSHIPS
•
T. Kato et al., Angew.Chem.Int.Ed.45, 38 (2006).
T. Kato et al., Chem.Commun., 729 (2009).
J.W. Goodby et al., Liq.Cryst. 36, 567 (2009).
W. Pisula et al., Macromol.RapidCommun. 30, 1179 (2009).
•OSCs: IMPORTANTES DATES
•LCs & LC OSCs: IMPORTANTES DATES
1977: DISCOVERY OF THE
1888: DISCOVERY OF CHOLESTERIC LCs BY (AUSTRIAN
CONDUCTING POLYMERS
BOTANIST) F. REINITZER & (GERMAN PHYSICIST)
O. LEHMANN
1983: 1st PFETs
st REPORT ON CALAMITIC LCs BY D. VORLÄNDER
1907:
1
st
1986: 1 EFFICIENT OLEDs
1977: 1st REPORT ON DISCOTIC LCs BY S. CHANDRASEKHAR
& SOLAR CELLS
1993: FAST PHOTOCONDUCTION IN π-CONJUGATED
1990: 1st PLEDs
1994 DISCOTIC LCOSCs BY D. HAARER et al.
1997: OLED DISPLAYS
1996: FAST PHOTOCONDUCTION IN π-CONJUGATED
2007: TV AM-OLEDs
1997 SMECTIC LCOSCs BY J.-I. HANNA et al.
11
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
ELECTRONIC TRANSPORT PROPERTIES OF LCOSCs:
PART I) DISCOVERY OF THE FAST PHOTOCONDUCTION
IN π-CONJUGATED DISCOTIC & SMECTIC LCOSCs
1996-1997
O
S
S
S
S
S
2-(dodecyloxy)-6-(4-octylphenyl)naphthalene
Cr 79°C SmB 100°C SmA 121 Iso
S
1993-1994
2,3,6,7,10,11-hexakis(hexylthio)triphenylene
Cr 62°C H (Colh*) 70°C Dh (Colhex*) 93°C Iso
O
N
S
S
1997
6-(dodecylthio)-2-(4-(heptyloxy)phenyl)benzo[d]thiazole
Cr 90°C SmA 100°C Iso
PHOTOCONDUCTION
IN LCOSCs
R.J. Bushby & O.R. Lozman,
Curr.Opin.SolidStateMater.
Sci. 6, 569 (2002).
M. O’Neill & S.M. Kelly,
Adv.Mater. 15, 1135 (2003).
M. Funahashi et al.,
Struct.Bond. 128, 151 (2008).
M. Funahashi & J. Hanna, Jpn.J.Appl.Phys. 335, L703 (1996).
By TOF: µh [SmA] up to 0.001 cm2.V-1.s-1
M. Funahashi & J. Hanna, Phys. Rev. Lett. 78, 2184 (1997).
By TOF: µh [SmA] up to 0.005 cm2.V-1.s-1
D. Adam et al., Nature 371, 141 (1994).
By TOF: µh= µe- [H] up to 0.1cm .V .s
2
-1
-1
D. Adam et al., Phys.Rev.Lett. 70, 457 (1993).
By TOF: µh= µe- up to 0.001 cm2.V-1.s-1
M. Funahashi & J. Hanna, Mol.Cryst.Liq.Cryst. 304, 429 (1997).
M. Funahashi & J. Hanna, Appl.Phys.Lett. 71, 602 (1997).
By TOF: µh=µ
µe- [SmB] up to 0.0016 cm2.V-1.s-1
By TOF: µh=µ
µe- [SmA] up to 0.00025 cm2.V-1.s-1
12
ELECTRONIC TRANSPORT PROPERTIES OF LCOSCs:
PART II) CHARGE CARRIER (HOLES/ELECTRONS) MOBILITY
AS PROBED BY THE PR-TRMC vs. TOF vs. LCOFET
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
•3D: ELECTRONIC TRANSPORT
WITHIN THE BULK
•CONTACT/ELECTRODE-LESS TECHNIQUE
•E- BEAM DOPING:
NANOSECOND PULSE OF 3 MeV ELECTRONS
Σµ= (µh + µe-) [cm2.V-1.s-1]
PR-TRMC
J.M. Warman et al., Chem.Mater. 16, 4600 (2004).
•3D: ELECTRONIC TRANSPORT WITHIN THE BULK
•CONTACT/WAVELENGTH-DEPENDENT
•PHOTO-DOPING:
PHOTO-GENERATED CHARGE CARRIERS
µh & µe- [cm2.V-1.s-1]
TOF
H. Iino & J. Hanna, Opto-Electron.Rev. 13, 295 (2005).
M. Funahashi et al., Struct.Bond. 128, 151 (2008).
LC OFET
Source
LC OSCs
Gate Dielectric
Gate
Drain
•2D: ELECTRONIC TRANSPORT CONFINED
@ THE GATE DIELECTRIC/OSC INTERFACE
•CONTACT-DEPENDENT
•FIELD-EFFECT DOPING:
ELECTRICALLY GENERATED CHARGE CARRIERS
µh & µe- [cm2.V-1.s-1]
Y. Shimizu et al., J. Mater. Chem. 39, 4223 (2007).
13
ELECTRONIC TRANSPORT PROPERTIES OF LCOSCs IN OFET
CONFIGURATIONS: STATE OF THE ART CHARGE CARRIER (HOLES &
ELECTRON) MOBILITY VALUES IN DISCOTIC & SMECTIC LCOSCs
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
Y. Shimizu et al.,
"Mesophase semiconductors in field effect transistors"
J.Mater.Chem. 39, 4223 (2007).
DISCOTIC
p-Type
LCOSCs
SMECTIC
n-Type
LCOSCs
DISCOTIC
n-Type
LCOSCs
SMECTIC p-Type LCOSCs
p-Type LCPSCs
14
THERMOTROPIC LC OSCs IN LC OFET CONFIGURATIONS: NEW
OPPORTUNITIES/PLAYGROUNDS FOR FUNDAMENTAL STUDIES ON LCOSCs
Source
Discotic
LCOSC
LCOFET
Top-Cover Glass
LC OSCs
Gate Dielectric
Gate
Drain
Source
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
LC OSCs
Gate Dielectric
Gate
Drain
LCOSCs’s CONFINEMENT (@ TWO DIFFERENT LENGTHSCALES)
WITHIN THE CHANNEL OF A LC OFET
-IN BETWEEN S & D (ca. µm-SCALE): GEOMETRICAL EFFECTS
-IN THE BEWTEEN THE GATE DIELECTRIC/AIR OR THE GATE
DIELECTRIC/TOP-COVER GLASS INTERFACE (DOWN TO
THE nm-SCALE): GEOMETRICAL EFFECTS
DISCOTIC LC OSCs
SMECTIC LC OSCs
TOROIDAL
DEFECTS
E. Grelet & H. Bock, Europhys. Lett. 73, 712 (2006)
Calamitic
LCOSC
Calamitic
LCOSC
P.O. Mouthuy et al., NanoLett. 7, 2627 (2007)
M.C. Choi et al., Proc.Nat.Acad.Sci. 101, 17340 (2004).
D.K. Yoon et al., Nat.Mater. 6, 866 (2007).
LCOFET
Y. Shimizu et al., J.Mater.Chem. 39, 4223 (2007).
J.C. Maunoury et al., Adv.Mater. 19, 805 (2007) 15
THERMOTROPIC LCOSCs IN LC OFET CONFIGURATIONS:
5 OPEN QUESTIONS (Q1-5)
UJF+UTA’s
Workshop on Nanosciences &
Nanotechnology: From Smart
Materials To Devices
Autrans, Oct.11-13, 2009
LCOSCs’s CONFINEMENT (@ TWO DIFFERENT LENGTHSCALES)
WITHIN THE (OPTO)ELECTRONICALLY ACTIVE CHANNEL OF AN LC
OFET UNDER OPERATION:
•MICRO & NANO-CONFINEMENTS INDUCED BY GEOMETRICAL
CONSTRAINTS
+
•ELECTRICAL CONFINEMENTS INDUCED BY THE FIELD-EFFECT
DOPING @ THE QUASI-2D LCOSC/GATE DIELECTRIC INTERFACE
Q1: NEW/DIFFERENT MESOMORPHISM FOR (KNOWN) LCOSCs?
Discotic
LCOSC
Calamitic
LCOSC
Calamitic
LCOSC
Y. Shimizu et al.,
LCOFET
Q2: A CONTROL OVER THE HOMOGENEOUS vs. HOMEOTROPIC
ALIGNMENT OF AN (OPTO)ELECTRONICALLY ACTIVE LCOSC
LAYER?
Q3: A WAY TO STABILIZE MONO-DOMAINS OF LCOSCs?
Q4: IMPACT ON THE DYNAMIC SELF-ASSEMBLY, SELF-HEALING
& (OPTO)ELECTRONIC FEATURES OF LCOSCs?
Q5: IMPACT ON THE (CASCADE OF) INTRICATE
(OPTO)ELECTRONIC PROCESSES @ WORK WITHIN LCOSCsBASED OFETs
Q1-5 : GENERIC ISSUES FOR LCOSCs-BASED
LEDs
LCOFET
MULTI-LAYER & BULK-HETEROJUNCTION SOLAR CELLS
J.Mater.Chem. 39, 4223 (2007).
LASERS
16