Carbon NanoBuds (CNB) Synthesis, Structure and Thin Film Device Applications Prof. Dr. Esko I. Kauppinen NanoMaterials Group (NMG) Department of Applied Physics Helsinki University of Technology (TKK) Espoo, Finland FINNISH-JAPANESE WORKSHOP on FUNCTONAL MATERIALS Säätytalo 26.5.2009, Helsinki, Finland
Nanobud Carbon nanotube NanoMaterials (NanoMat) Group Department of Applied Physics and Center for New Materials Helsinki University of Technology (TKK) http://www.fyslab.hut.fi/nanomat 1). Synthesis of carbon nanotubes and nanobuds 2). Synthesis of multicomponent nano- and microparticles for drug and gene delivery 3). Structural characterization of nanotubes and nanoparticles by electron microscopy 4). Generation of novel 2-D and 3-d nanotube, nanobud and polymer/protein structures for transparent electronics and energy applications 5). MD and DFT
NanoMaterials Group, Helsinki University of Technology Dept. of Applied Physics & Center for New Materials Dr. Albert G. Nasibulin Dr. Hua Jiang Dr. Janne Raula Mrs. Jing Tian Ms. Marina Zavodchikova Also: Antti Kaskela, Toma Susi Dr. David P. Brown CEO, Canatu Oy NEDO http://www.fyslab.hut.fi/nanomat/ Acknowledgement for Funding * Academy of Finland * EU FP6 & FP7 * TEKES FinNano Program TKK 100th Anniv. Fund
Personnel 1 prof. and 5 post-docs 10 graduate and 7 undergraduate students Doctoral level expertise Carbon nanotubes, nanobuds, metal oxide nanowires (Albert G. Nasibulin - phys.chem) Drug, polymer, peptide and protein chemistry, nanoparticle synthesis and CNT & CNB surface functionalisation (Janne Raula polymer mat.) Transmission electron microscopy of nanomaterials (Hua Jiang - physics) Electrochemistry with carbon nanomaterials FC&SC (Virginia Ruiz phys. chem) Molecular dynamics and DFT (Markus Kaukonen - physics) External Funding More than 1 000 k /year EU: BNC Tubes Strep 2007-2010 3 500 k ; NanoTox SSA Academy of Finland (e.g. NanoDuraMEA), TEKES, companies CNB-E 2008-2012 MIDE/TKK 100 Years Anniversary Research Program
Acknowledgements for Collaboration Prof. Yutka Phno, Nagoya U. Prof. Florian Banhart, U. Strasbourg Brad Aitchison, Jussi Sarkkinen, Canatu Oy Dr. Peter V. Pikhitsa and Prof. Mansoo Choi National CRI Center for Nano Particle Control, Institute of Advanced Machinery and Design, Seoul National University, Korea Dr. Abdou Hassanien and Dr. Günther Lientschnig AIST, Tsukuba, Japan Dr. Giulio Lolli and Prof. Daniel E. Resasco Chemical Biological and Materials Engineering, University of Oklahoma, USA Dr. Arkady V. Krasheninnikov and Prof. Risto Nieminen Laboratory of Physics, Helsinki University of Technology, Finland Prof. David Tománek Physics and Astronomy Department, Michigan State University, USA
Known forms of Carbon Nanomaterials Carbon Nanotube (SWCNT): Roll of carbon sheet one atomic layer thick = Graphene NanoRibbons (GNR) 1 000 000 times thinner than paper Rolling in different directions makes different kinds of tubes (10,10) armchair tube METALLIC (10,5) helical (chiral) tube SEMICONDUCTING By Prof. Shigeo Maruyama, Tokyo Universssity, Japan
CNTN -Materials for Flexible Electronics CNTN FET Mobility Year According to Prof. G. Gruner, UCLA,USA
Properties of Carbon Nanotubes Better conductor than copper Better transistor material than silicon Conduct heat twice as efficiently as diamond Field emit 500 times as efficiently as molybdenum Thermally stable up to 1500 o C while polymers degrade below 150 o C Half as dense as aluminum 25 times stronger than steel Very inert and difficult to integrate into composite materials and to incorporate into electronics manufacturing
Three allotropic modifications of carbon: diamond, graphite, and fullerene structures (fullerenes and CNTs).?? PEAPOD Graphene
CNB- Carbon NanoBud TM New Carbon NanoMaterial Nanobud TM combines Carbon Nanotubes and Fullerenes in Single Structure with Covalent Bonding Nasibulin & Kauppinen et al. Nature Nanotechnology, 2(3) 156 March 2007
Content of the Talk CNB s (Carbon NanoBuds = C 60 +SWCNT) floating CVD synthesis, structure and properties Novel Dry Thin Film Device Manufacturing Method Field Electron Emission of CNB vs SWCNT films Transparent flexible electrode and TFT Preliminary results on nanocarbon PEMFC applications
HIGH HEATING ZONE TEMPERATURE ZONE 900 C Bundling α N CNT2 α N Cat 2 CO2 CO. CO. C C+CO2 = 2CO End of CNT growth - CARBON DISPROPRTIONATION IS PROHIBITED (t > 900 C) CO2 reaction with amorphous carbon: Mechanism of CNB Formation from CO with Fe Cluster Catalyst H2O CO.. CO H2.. CO2. CO H2 Steady-state growth of CNT - C INCORPORATION INTO GRAPHENE LAYER - REACTIONS OF CARBON RELEASE AND ETCHING: 2CO<=>C+CO2 AND H2+CO<=>C+H2O CNT nucleation - HEPTAGON FORMATION CO H O 2 Formation of graphene layer - HEXAGON AND PENTAGON FORMATION - REACTIONS ON REACTOR WALLS: 2CO=C+CO2 H2+CO=C+H2O - CO2 AND H2O RELEASE 400 C. H2O. CO. CO2. CO. CO CO.. H2. CO CO... H2.................................. H2/N2.... CO... H2. H2. CO Fe(g) Particle saturation by C - REACTIONS: 2CO=C+CO2 AND H2+CO=C+H2O - C RELEASE ON SURFACE - C DISSOLUTION FE particle formation - VAPOUR NUCLEATION - CONDENSATION - CLUSTER COAGULATION CO H O 2 CO CO 2
Synthesis of NanoBuds (CNB) add CO 2 or H 2 O HWG method Ferrocene-based method
Lab scale (7) and pilot scale (1) reactors for CNT&CNB synthesis and in-situ thin film-based device manufacturing Flow reactors (3) for nanoparticle synthesis Lab scale reactors Pilot scale reactor
CNB formation mechanisms Fullerenes nucleate from the graphene at the cluster surface Fullerens attached to graphene at Fe cluster surface
TEM of CNB Fe Catalyst via PVD Carbon from ethanol 10 nm 10 nm
TEM observation of the sample after washing in toluene and decaline Conclusion: nothing happened with fullerenes, they were not dissolved stronger than Van der Waals bonding toluene decaline 10 nm 5nm
Controll of Fullerene density on CNB s via H 2 O increase H 2 O concentration 10nm 10 nm 10nm increase H 2 O concentration 10 nm 10 nm 10 nm 10nm 10 nm
0-20 cm 3 /min position in reactor, cm CO 300 cm 3 /min CO 100 cm 3 /min Synthesis of Carbon NanoBuds 885 ºC ferrocene cartridge water cooling circulation 0 particles CNTs and fullerenes 10 20 0.2 µm 945 ºC water 30 10 nm CO2 or N2 dilutor N 2 12 L/min FT-IR/ ESP 40 50 200 400 600 800 1000 1200 Temperature, C 2 nm Filter 0.2 µm A.G.Nasibulin & E.I.Kauppinen et al, Chem.Phys.Lett, 446(2007), 109-114.
NanoBuds TM on FEI Titan TEM at 80kV with image C s -corrector - Movie Individual Fullerene Cluster of Fullerenes Fullerenes are NOT removed by electron beam Image :B.Freitag FEI; samples : Prof. Kauppinen Helsinki, Finnland
Frequency Number size distribution of NanoBud TM fullerenes measured from HR-TEM images 0.30 0.25 C 60 0.20 C 42 0.15 0.10 C 34 C 86 0.05 C 20 0.00 0.43 0.45 0.41 0.47 0.50 0.55 0.58 0.52 0.60 0.63 0.67 0.70 0.73 0.77 0.81 0.85 0.89 0.93 0.98 1.03 0.390.410.430.450.470.5 Diameter 0.520.550.580.6 of fullerenes 0.630.670.7 0.730.770.810.850.890.930.98 (nm)
Comparison of ultraviolet-visible absorption spectra of CNB s, C 70 and C 60 standards Absorbance (au) Fullerene absortion bands: 4.0 in hexane: in toluene: C 60 C 60 SWCNT absortion bands: 3.5 C 70 C 70 FFCNTs FFCNTs 3.0 2.5 2.0 700 800 900 1000 1100 1.5 1.0 0.5 0.0 200 300 400 500 600 Wavelength (nm)
Intensity (au) Raman spectra of NanoBuds carried out by using red (633 nm), green (514 nm), and blue (488 nm) lasers. 2.0x10 4 1.5x10 4 1.0x10 4 5.0x10 3 0.0 200 400 600 800 1000 1200 1400 1600 1800-1
Bonding scenarios of fullerenes on nanotubes based on DFT calculations Calculations By Arkady Krasheninnikov, TKK
LT UHV STM: Chemisorbed Fullerene on Nanotube Lattice Ambient STM Peaks in the LDOS are due to nanobuds, cannot be assigned to physisorbed fullerenes Nanometer Range Controll for DOS! Nasibulin & Kauppinen et al. Nature Nanotechnology, 2(3) 156 March 2007
Calculations by Arkady Krasheninnikov, TKK Experiment This suggests that chemically attached fullerene via 2+2 cycloaddition is energetically favorable
Dry, direct deposition method for Integrated Component Manufacturing Synthesis Process.. CNT Aerosol Deposition Process Products Control of Material Direct Manufacture
Traditional CNT film processes are complex Increases cost and may deteriorate performance Produce CNT powder Collect CNT powder Acid purify & sonicate Dirty raw bundled CNTs aerosol or on substrate Chemically purify, functionalize & dry Dirty raw bundled CNTs as powder Filter, spray or spin coat and dry Clean bundled damaged CNTs in liquid Surfactant treat & centrifuge Clean unbundled functionalized damaged CNTs on substrate Surfactant coated unbundled damaged CNTs on substrate Surfactant coated unbundled damaged CNTs in liquid
CO 300 cm 3 /min CO 100 cm 3 /min furnace Experimental set up: Ferrocene Reactor 2930 500 100 ferrocene cartridge water cooling circulation Catalyst precursor: 85 Ferrocene: 35 Fe(C 24 5 H 5 ) 2 6 Carbon source: Fe CO + CO = C(s) + CO 2 N 2 12 L/min FT-IR dilutor ESP Moisala, Nasibulin, Brown, Jiang, Khriachtchev, Kauppinen, (2006) Chem. Eng. Sci. 61, 4393. Filter
Small Reactor Large Reactor Flow rate 0.3 liters/min Reactor Tube Diameter Inner 2.5 cm Lentgh 50 cm Flow rate 10-100 x Small Reactor
SEM images demonstrating CNT film densification by ethanol (b) as deposited CNT film after treatment with ethanol Nasibulin, Ollikainen, Kauppinen et al. Chem. Engin. J. (2008) 136, 409.
Cold field emission properties of as-deposited CNB films on Au substrate: comparison with SWCNTs Current density ( A/cm 2 ) 700 600 500 400 300 200 100 4 3 2 1 0 0.0 0.5 1.0 1.5 2.0 2.5 SWNTs NanoBuds (H2O: 65 ppm) NanoBuds (H2O: 100 ppm) NanoBuds (H2O: 150 ppm) 0 0.0 0.5 1.0 1.5 2.0 2.5 Field strength (V/ m) ACCVD; Tanamura et al., APL (2006)- SWCNT grown on glass
- Large reacto
Large reactor tubes - HRTEM at 385C
Large reactor tubes - HRTEM at 485C Maria A1 Ethanol treatment heating 485C
Large reactor tubes - HRTEM at 485C
Dry deposition of CNT networks for TF-FETs Condensation particle counter (CPC) substrate holder 12х12mm Schematic of an ESP substrate size is up to 12х12mm Metal Teflon Metal T.J. Krinke et al., Aerosol Science 33, 2002
Estimated average density [CNT bundles/um 2 ] CNT networks with various densities ρ calc.~12 CNT bundles/µm 2 ρ calc.~8 CNT bundles/µm 2 12 12 10 10 8 8 12 10 8 6 6 6 4 4 4 SiO 2 SiO 2 Cr2 2 AZ 2 0 0 0 0 1 2 3 4 5 Deposition time [min] ρ calc.~5 CNT bundles/µm 2 ρ calc.~2,5 CNT bundles/µm 2 ρ calc.~1 CNT bundles/µm 2 Cr SiO 2 SiO 2 SiO 2 Cr calc. t C Q S ρ-estimated average density (CNTs/µm 2 ); t-time of collection; C-particle concentration by CPC (CNTs/cm 3 ); Q- particle flow (cm 3 /min); S-substrate area (µm 2 ).
SWCNTN FETs on Si and Kapton substrates on/off`= 10 5, mobility = 5 cm 2 /(V*s) on Si (L=W=50 µm) on/off`= 10 5, mobility = 1cm 2 /(V*s) on polymer (L=150 µm, W=200 µm)
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