Organic Materials                                                                              Chemistry                  ...
2012 AFOSR SPRING REVIEWNAME: Charles LeeBRIEF DESCRIPTION OF PORTFOLIO:To exploit the uniqueness of organic/polymeric mat...
Research Objective and ChallengesTo exploit the uniqueness of organic/polymeric materials technologies   for enabling futu...
Other Organizations That Fund                Related Work• Other Basic Research Organization in this area:   – ONR, ARO, N...
Organic Lasers Achieve CW Lasing                        Stephen Forrest, U of MichiganWhy does Organic Semiconductor Laser...
Triplet Management Decreases                  Saturation Density                                                     SHost...
Exceeding the CW threshold                                                             Conditions                        ...
A Bottom-up Pathway to Chiral                  Metamaterials                    Paras Prasad, U of Buffalo                ...
First demonstration of plasmonic enhancement of chirality                in a polymeric thin film doped with gold NPs.    ...
First demonstration of excitonic                             enhancement of chirality                       First demonstr...
Process flow for PFBT/SU8                     Photopatterning                                                             ...
Photopatterning of Chiral Polymers  First demonstration of chirality enhancement by doping a chiral polymer in an         ...
Exquisite Control of Molecules to          Direct Chemical Reactions                         Alex Jen, U of WashingtonSelf...
Molecular Design for Regio-selective                Reaction on SurfacePEA Photoreaction                                  ...
Self Assembly Monolayer with                 Confined MPEA• Tunable number and size of defectsites dependent on concentrat...
Study of Single Molecule Switching       Dynamics in Confined Environment                                                 ...
Electricity Generation with Body heat                                      Choongho Yu, TA&M           First demonstration...
Fabrication of polymer                               NanocompositesMix CNTs and aqueous         Disperse CNTs by          ...
Controlling Junctions & Surfaces                                     and Material MorphologyModifying junctions and surfac...
Electrical Transport Increase                 without Changing Thermal Power                                     Power    ...
Double-Wall Nanotubes                                       2.5x105                                                       ...
Layer by Layer Removal of Graphene:single-atomic-layer-resolution lithography  Dimiev, A.; Kosynkin, D. V.; Sinitskii, A.;...
Layer-by-layer removal and                  patterning of GOThe method works with the four different types of graphene and...
Graphene nanoribbons heat circuit as de-icing          coating for phased array antennas and radomes                      ...
Large Area De-icing coating for              Antenna and Radome                  Collaboration with Lockheed MartinSpray c...
Growth of Graphene from any Carbon                        Source                             J. Tour, Rice UniversityImpur...
Graphene from Girl Scout CookiesConverted to a single sheet of graphene, one box of Girl Scout Cookies can be         wort...
Upconversion with Terrestrial Solar            Photons        DISTRIBUTION A: Approved for public release; distribution is...
Upconversion-Powered Water Splitting       Photoelectrochemistry               F. Castellano, Bowling Green UThe first exa...
Upconversion Visualized in a PEC CellPhotograph of the cell in action, pumped                              Shuttered curre...
Recognitions       Metamaterials and plasmonics for rf photonics                     Rf waveguide                         ...
Summary•   Program Focused on developing New and Controlled    Properties•   Not applications specific, but often use appl...
Upcoming SlideShare
Loading in …5
×

Lee, Charles - Organic Materials Chemistry - Spring Review 2012

1,136
-1

Published on

Dr. Charles Lee presents an overview of his program - Organic Materials Chemistry - at the AFOSR 2012 Spring Review.

Published in: Technology
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
1,136
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
26
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

Lee, Charles - Organic Materials Chemistry - Spring Review 2012

  1. 1. Organic Materials Chemistry 09 MAR 2012 Charles Lee Program Manager AFOSR/RSA Air Force Research LaboratoryIntegrity  Service  Excellence DISTRIBUTION A: Approved for public release; distribution is unlimited
  2. 2. 2012 AFOSR SPRING REVIEWNAME: Charles LeeBRIEF DESCRIPTION OF PORTFOLIO:To exploit the uniqueness of organic/polymeric materialstechnologies for enabling future capabilities currently unavailable bydiscovering and improving their unique properties and processingcharacteristicsLIST SUB-AREAS IN PORTFOLIO:Photonic Polymers/OrganicsElectronic Polymers/OrganicsNovel Properties Polymers/OrganicsNanoTechnology DISTRIBUTION A: Approved for public release; distribution is unlimited 2
  3. 3. Research Objective and ChallengesTo exploit the uniqueness of organic/polymeric materials technologies for enabling future capabilities currently unavailable by discovering and improving their unique properties and processing characteristicsChallenges:- Discover New Properties- Control Properties- Balance Secondary PropertiesApproach:–Molecular Engineering–Processing Control–Structure Property Relationship • Program Focused on developing New and Controlled Properties • Not applications specific, but often use applications to guide the properties focuses DISTRIBUTION A: Approved for public release; distribution is unlimited 3
  4. 4. Other Organizations That Fund Related Work• Other Basic Research Organization in this area: – ONR, ARO, NSF, NIH, DOE• Other Non-Basic Research Organizations: – AFRL/TDs, ARL, NRL, DARPA, NRO, DTRA – DOE, JEIDDO, NIST• Interactions with Other Agencies – Federal Interagency Chemistry Representatives Meeting – Tri-Service Laser Protection Information Exchange Meeting – Joint AFOSR-ONR Organic Photovoltaic Program Review – Tri-Service 6.1 MetaMaterials Review DISTRIBUTION A: Approved for public release; distribution is unlimited 4
  5. 5. Organic Lasers Achieve CW Lasing Stephen Forrest, U of MichiganWhy does Organic Semiconductor Laser lasing only last <100ns? Initial conditions after pulse (<10ns) Step Optical Negligible Triplet density Intensity Pump Gain=Loss Lasing begins Later (>100ns) Triplets build up, along with triplet losses Gain ↓ due to S-T quenching Lasing Time Loss ↑ due to T absorption Turn-off Giebink, N. C.; Forrest, S. R. Phys. Rev. B 2009, 79, 073302 Lehnhardt, M.; Riedl, T.; Weimann, T.; Kowalsky, W. Phys. Rev. B 2010, 81, 165206 Conclusion: To reach CW lasing threshold, the triplet state density must reach a steady state. DISTRIBUTION A: Approved for public release; distribution is unlimited 5
  6. 6. Triplet Management Decreases Saturation Density SHost: S EmissionAlq3 S T=2.0eV T=1.7eV T=1.8eV T Host Guest managerEmitter: Alq3 DCM2 ADNDCM2 1.0 Intensity (arb. unit) Alq3 0.8 PL (normalized)Manager 0.6 DCM2: ADN ADN Alq3 DCM2 0.4 ADN 0.2 1.5 1.8 2.1 2.4 Energy (eV) 0.0 Triplet State 400 500 600 700 measurement Wavelength (nm) DISTRIBUTION A: Approved for public release; distribution is unlimited 6
  7. 7. Exceeding the CW threshold  Conditions  2.4kW/cm2, 10Hz/18μs  Consistent with theory Single pulse  100 μs lasing time  Degradation limited  Implications:  Higher intensity and higher efficiency OLEDs  Significant step toward electrically pumped lasing “Continuous-wave threshold exists for organic semiconductor lasers”, Y. Zhang and S. R. Forrest, Phys. Rev. B, 84, 241301 (2011).“Enhanced efficiency in high-brightness fluorescent organic light emitting diodes through triplet management”, Y. Zhang, et al., Appl. Phys. Lett., 99, 223303distribution is unlimited DISTRIBUTION A: Approved for public release; (2011). 7
  8. 8. A Bottom-up Pathway to Chiral Metamaterials Paras Prasad, U of Buffalo Pushing  toward values ≥1 will enable chiralneff     optical metamaterials Synthesize new chiral conjugated polymers with high intrinsic optical activity at visible wavelengths (molecular-scale chirality) Control the supramolecular organization of these chiral polymers to maximize chirality in thin film nanocomposites (supramolecular chirality) Create nanocomposites with inorganic components that enhance chirality  Metallic nanocrystals (gold, silver) for plasmonic enhancement  Semiconductor nanocrystals (quantum dots) for excitonic enhancement Pattern nanocomposites to create chiral nanostructures (meso- scale chirality) DISTRIBUTION A: Approved for public release; distribution is unlimited 8
  9. 9. First demonstration of plasmonic enhancement of chirality in a polymeric thin film doped with gold NPs. First demonstration of plasmonic enhancement of chirality in a polymeric thin film doped with gold NPs 1000 PFBT PFBT- AuNPs(8nm), 1/1 500 0 CD(mdeg)on -500 -1000 N S N n -1500   0.02 Poly(fluorene-alt- -2000 300 400 500 600 700 800 benzothiadiazole) Wavelength(nm) (PFBT) film with dispersed Au NPs neff     “Chiral Poly(fluorene-alt-benzothiadiazole) (PFBT) and Nanocomposites with Gold Nanoparticles: Plasmonically and Structurally Enhanced Chirality,” Heong Sub Oh, Sha Liu, HongSub Jee, Alexander Baev, Mark T. Swihart, and Paras N. Prasad, Journal of the American Chemical Society, 2010, 132, 17346–17348. (cited 13 times within 1 year of online publication) DISTRIBUTION A: Approved for public release; distribution is unlimited 9
  10. 10. First demonstration of excitonic enhancement of chirality First demonstration of excitonic enhancement of chirality in a polymeric thin film doped with quantum dots.tion n N S N Polyfluorene film (PFBT) with dispersed CdTe/ZnS quantum dots neff      ~ 0.03 Manuscript in preparation A: Pure PFBT B: PFBT with CdTe/ZnS DISTRIBUTION A: Approved for public release; distribution is unlimited 10
  11. 11. Process flow for PFBT/SU8 Photopatterning UV light PFBT/SU8 solution Pre-bake, 95 °C Shadow mask Spin-coat PFBT/SU8 film PFBT/SU8 film Glass Substrate Glass Substrate Glass Substrate Cross-linked Exposed Region Glass Substrate Glass Substrate Glass SubstrateRinse with propanol Post-bake, 95 °Cand dry with nitrogenDevelop in PGMEA PFBT aggregates left behind Cross-linked PFBT/SU8 nanocomposite Glass Substrate DISTRIBUTION A: Approved for public release; distribution is unlimited 11
  12. 12. Photopatterning of Chiral Polymers First demonstration of chirality enhancement by doping a chiral polymer in an achiral photoresist matrix with subsequent photopatterning.   0.017 Polyfluorene PFBT co-dissolved with SU-8, cast into a film and photopatterned with UV light“Dramatic Structural Enhancement of Chirality in Photopatternable Nanocomposites of ChiralPoly(fluorene-alt-benzothiadiazole) (PFBT) in Achiral SU-8 Photoresist,” Heong Sub Oh, Hongsub Jee,Alexander Baev, Mark T. Swihart and ParasA:N. Prasad, submitted toisACS Nano. DISTRIBUTION Approved for public release; distribution unlimited 12
  13. 13. Exquisite Control of Molecules to Direct Chemical Reactions Alex Jen, U of WashingtonSelf-assembly of Inert Self-assembly ofMolecules to Confine Photoactive Molecules to Environment Control Orientation Stochastic switching Increased conductance of excited state Photon- STM Decreased conductance of photoproduct Kim, Houk, Ma, Jen, Weiss, Science 2011, 331, 1312. Highlighted by Chem. & public release; distributionMarch 14, 2011. DISTRIBUTION A: Approved for Eng. News is unlimited 13
  14. 14. Molecular Design for Regio-selective Reaction on SurfacePEA Photoreaction +(9-phenylethynylanthracene) 9-(4-mercaptophenylethynyl) 9-phenylethynylanthracene anthracene (MPEA) disulfideIn solution:a) Diels-Alder reaction [4+2] On surface:b) Photocycloaddition [4+4] a) rarely happens because of Creating defect sites of a + alkanethiolate SAM geometric constraints b) Tethering two MPEA molecules next SH SH S S to each other on Au surface c) Poising in the correct orientation to force photocycloaddition Kim, Houk, Ma, Jen, Weiss, Science 2011, 331, 1312. Highlighted by Chem. & public release; distributionMarch 14, 2011. DISTRIBUTION A: Approved for Eng. News is unlimited 14
  15. 15. Self Assembly Monolayer with Confined MPEA• Tunable number and size of defectsites dependent on concentration ofn-dodecanethiol in ethanol and timeof vapor annealing • Disulfide molecules assured adjacent placement of molecules DISTRIBUTION A: Approved for public release; distribution is unlimited 15
  16. 16. Study of Single Molecule Switching Dynamics in Confined Environment Arrow sites: increased conductance of molecular excited state a)Box sites: Decreased conductance of molecular photoproduct b) DISTRIBUTION A: Approved for public release; distribution is unlimited 16
  17. 17. Electricity Generation with Body heat Choongho Yu, TA&M First demonstration of electricity generation from polymeric materials VoltageCut by Connected toscissors a multimeter Time Voltage –Time responseFlexible TE polymers DISTRIBUTION A: Approved for public release; distribution is unlimited 17
  18. 18. Fabrication of polymer NanocompositesMix CNTs and aqueous Disperse CNTs by Pour the mixture Dry further in an oven orstabilizer solution (e.g., sonication and then (if into a plastic container dessicator to removePEDOT:PSS) necessary) add polymer and dry at room temp. micro voids and moisture emulsions (e.g., PVAc) with sonication DISTRIBUTION A: Approved for public release; distribution is unlimited 18
  19. 19. Controlling Junctions & Surfaces and Material MorphologyModifying junctions and surfaces Scattering JunctionIt is feasible to dramatically Heat Nanoparticlechange: transport- Electrical conductivity- Thermopower- Thermal conductivity Nanotubefor desired objectives. Electron transport (by hopping) Phonon density of states Material A Material B Phonon transport Vibrational across junction Spectra mismatch can be suppressed. Frequency DISTRIBUTION A: Approved for public release; distribution is unlimited 19
  20. 20. Electrical Transport Increase without Changing Thermal Power Power Factor Used p-HipCo SWCNTsYu et al. ACS Nano, 5, 7885 DISTRIBUTION A: Approved for public release; distribution is unlimited (2011). (high CNT concentrations) 20
  21. 21. Double-Wall Nanotubes 2.5x105 70  60 Electrical conductivity, (S/m) 2.0x105 S Thermopower, S (V/K) 50 1.5x105 40 800 30 105 S2W/m-K2) 600 800 % 400 20 5.0x104 improvement in 200 Power Factor 10 0 over SWNT 0 20 40 60 80 100 CNT wt% 0 0 0 20 40 60 80 100 Double-wall carbon nanotube wt% Carbon nanotube wt%DWNT + PEDOT:PSS only composites DISTRIBUTION A: Approved for public release; distribution is unlimited 21
  22. 22. Layer by Layer Removal of Graphene:single-atomic-layer-resolution lithography Dimiev, A.; Kosynkin, D. V.; Sinitskii, A.; Slesarev, A.; Sun, Z.; Tour, J. M. “Layer-by-Layer Removal of Graphene for Device Patterning,” Science 2011, 331, 1168-1172. DISTRIBUTION A: Approved for public release; distribution is unlimited 22
  23. 23. Layer-by-layer removal and patterning of GOThe method works with the four different types of graphene and graphene-like materials: -graphene oxide, -chemically converted graphene, -chemical vapor–deposited graphene (CVDG), -and micromechanically cleaved (“clear-tape”) graphene DISTRIBUTION A: Approved for public release; distribution is unlimited 23
  24. 24. Graphene nanoribbons heat circuit as de-icing coating for phased array antennas and radomes Yu Zhu; Wei Lu and James M. Tour* Quenched with styrene Department of Chemistry and Smalley Institute, Rice University, Houston, TX 77005 2 um Quenched with isopreneThe MWCNTs are split by the potassium metal vaportreatment and retain the resiliently rigid mechanicalproperties of the parent nanotubes. The producedgraphene nanoribbons are highly conductive (800S/cm) and dispersible in solvents such aschlorosulfonic acid and othordichlorobenzene. ACSNano 2011, ASAP. 4 umA thin graphene nanoribbon film is practically transparent for RFelectromagnetic waves.With the layer thicknesses around 100 nm ,the film is suitable for a de-icingcover to replace conventional heat circuits for phased array antennas andradomes. DISTRIBUTION A: Approved for public release; distribution is unlimited 24
  25. 25. Large Area De-icing coating for Antenna and Radome Collaboration with Lockheed MartinSpray coated GRN film on flexible De-icing test under -20°C conditions polymer substrate •Thickness of heating layer is not more than 100 nm •Transparency for RF radar signals of any polarization •10 grams of graphene nanoribbons per 10 m x 10 m antenna aperture/face. Cost isA:$10 in public release; distribution is unlimited nanoribbon starting material DISTRIBUTION Approved for 25
  26. 26. Growth of Graphene from any Carbon Source J. Tour, Rice UniversityImpurities remain on top of foil 1000°CRuan, G.; Sun, Z.; Peng, Z.; Tour, J. M. “Growth of Graphene from Food, Insects,and Waste,” ACS Nano 2011, 5, 7601–7607. distribution is unlimited DISTRIBUTION A: Approved for public release; 26
  27. 27. Graphene from Girl Scout CookiesConverted to a single sheet of graphene, one box of Girl Scout Cookies can be worth $15 billion, and would cover nearly 30 football fields Google “graphene girl scout cookie”= 51,000 hits. The YouTube video has public release; distribution istoo. DISTRIBUTION A: Approved for 40,000 hits unlimited 27
  28. 28. Upconversion with Terrestrial Solar Photons DISTRIBUTION A: Approved for public release; distribution is unlimited 28
  29. 29. Upconversion-Powered Water Splitting Photoelectrochemistry F. Castellano, Bowling Green UThe first example of water-splitting photoelectrochemistry being operated solely under the influence of upconverted photons. Chem. Commun. 2012, 48, 209-211. DISTRIBUTION A: Approved for public release; distribution is unlimited 29
  30. 30. Upconversion Visualized in a PEC CellPhotograph of the cell in action, pumped Shuttered current/time response of aby long-pass filtered lamp light delivered WO3 photoanode biased to +0.9 V vsvia fiber optics to the outside of the Ag/AgCl in 1.0 M H2SO4PhotoElectroChemical (PEC) cell DISTRIBUTION A: Approved for public release; distribution is unlimited 30
  31. 31. Recognitions Metamaterials and plasmonics for rf photonics Rf waveguide Rf Input Optical Fiber Optical Fiber Signal out Signal out EO modulator New Hybrid Antenna Rf AntennaOn Going Transition:EO Polymer is one of the key technologies for its development in AFRL DISTRIBUTION A: Approved for public release; distribution is unlimited 31
  32. 32. Summary• Program Focused on developing New and Controlled Properties• Not applications specific, but often use applications to guide the properties focuses• Scientific Challenges - Discover New Properties - Control Properties - Balance Secondary Properties• General Approaches - Molecular Design Flexible Photodetector - Processing Control - Establish Structure Properties Relationship DISTRIBUTION A: Approved for public release; distribution is unlimited 32
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×