Dynamics of Excited States in Nanoscale Materials

Brian M. Tissue

Department of ChemistryVirginia Polytechnic Institute and State UniversityBlacksburg, VA 24061tissue@vt.edu

Outline

History and terminology Materials preparation Materials characterization Dynamics Summary

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Fire Opal

E. Fritsch et al., The nanostructure of fire opal, J. Non-Cryst. Solids, 352 (2006) 3957.

Chip Clark, http://www.mnh.si.edu/

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Natural Nanostructures

Manuka (scarab) beetle Morpho Butterfly

Andrew R. Parker & Helen E. Townley, Biomimetics of photonic nanostructures, Nature Nanotechnology 2 (2007) 347. 4

Antireflective Moth Eyes

http://www.asknature.org/

Reflexite display Optics product data sheethttp://www.physorg.com/news122899685.html; C.-H. Sun, P. Jiang, and B. Jiang, Broadband moth-eye antireflection coatings on silicon, Appl. Phys. Lett. 92 (2008) 061112 5

Copyright Trustees of the British Museum, http://www.britishmuseum.org.

The Lycurgus Cup

Reflected light Transmitted light

Late Roman, 4th century AD(colloidal gold and silver)

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Michael Faraday 1857

http://aveburybooks.com/faraday/catalog.htmlM. Faraday, The Bakerian Lecture: Experimental Relations of Gold (and Other Metals) to Light,, Phil. Trans. R. Soc. Lond., 147 (1857) 145.

...mere variation in the size of its particles gave rise to a variety of resultant colours.

The state of division of these particles must be extreme; they have not as yet been seen by any power of the microscope.

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Monolayer Films

Benjamin Franklin (1771) dropped ‘not more than a Tea Spoonful’ of oil onto Clapham Pond

Lord Rayleigh (1890) calculated film thickness to be 1.6 nm

Agnes Pockels, Surface Tension, Nature 43 (1891) 437.

1930s Langmuir-Blodgett films 1940 Katharine Blodgett anti-reflective glass

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Working Definition of Nanoscale

fine particles: 100 to 2500 nm nanomaterials: one or more dimensions between

1 and 100 nm ultrafine particles, nanoparticles, nanocrystals,

quantum dots (semiconductors) nanocubes, nanosheets, nanoplates, nanowires,

nanoflowers, etc. nanorods (solid), single-walled and multi-walled

nanotubes (hollow) clusters: few to hundreds of atoms

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http://cobweb.ecn.purdue.edu/~janes/whats_nano.htm 10

Nanoscale Descriptors

by medium: colloids, aerosols, hydrosols by number of phases: nanocomposite by construction: nanoarrays, nanostructures

(often on surface) aspect ratio: length-to-width size distribution:

< ±10 %: monodispersed > ±10 %: polydispersed

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L.B. Kiss et al., The real origin of lognormal size distributions of nanoparticles in vapor growth processes, Nanostruct. Mater. 12 (1999) 327-332.

Nanocomposites/Nanostructureshttp://www.nrc-cnrc.gc.ca/eng/news/nrc/2003/07/03/nanocomposites.html

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T. C. Chong et al., Laser precision engineering: from microfabrication to nanoprocessing, Laser & Photon. Rev. 4 (2010) 123.

Nanoparticles are Composites

Andrew Maynard, NIOSH and Yasuo Ito, Argonne National Lab, NSF Workshop Report on “Emerging Issues in Nanoparticle Aerosol Science and Technology (NAST)” University of California, Los Angeles, June 27-28, 2003.

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Materials Preparation

Bottom-up (chemical) easier to scale up

Top-down (physical) precise control of

dimensions and proximity

Hybrid (scaffolding)

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Bottom Up

gas-phase inert-gas

condensation spray pyrolysis pulsed-laser

deposition

condensed-phase homogeneous

precipitation seed-mediated

growth self-assembly

(micellar) sol-gel glass-ceramic

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Controlling Nucleation and Growth

NSF Workshop Report on “Emerging Issues in Nanoparticle Aerosol Science and Technology (NAST)” University of California, Los Angeles, June 27-28, 2003. 16

Top Down

lithography block copolymer

patterning optical interference electron beam

(scribing)

contact embossing/molding pattern transfer dip pen lithography

17M. Volatier et al., Extremely high aspect ratio GaAs and GaAs/AlGaAs nanowaveguides fabricated using chlorine ICP etching with N2-promoted passivation, Nanotech. 21 (2010) 134014.

Light Well: ATunable Free-Electron Light Source on a Chip

related to Smith–Purcell effect

G. Adamo et al., Phys. Rev. Lett. 103 (2009) 113901. 18

Materials Characterization

Small angle X-ray scattering

Electron microscopy

Scanning probe microscopy

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I review for J. Lumin.

X-ray Scattering at APS

grazing-incidence small-angle X-ray scattering (GISAXS)

ultrasmall-angle X-ray scattering (USAXS)

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Z. Jiang et al., Capturing the Crystalline Phase of Two-Dimensional Nanocrystal Superlattices in Action, Nano Lett. 10 (2010) 799–803.

F. Zhang, et al., Quantitative Measurement of Nanoparticle Halo Formation around Colloidal Microspheres in Binary Mixtures, Langmuir 24 (2008) 6504-6508.

2 nm

Imaging Methods

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Veeco Instruments, Application Note AN48.

1−103 500−10810−106

HRTEM: Defects in BN Sheet

O.L. Krivanek et al., Atom-by-atom structural and chemical analysis by annular dark-field electron microscopy, Nature 464 (2010) 571.

red: borongreen: nitrogenyellow: carbonblue: oxygen

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HRTEM: Citrate-capped gold n.p.

Z. Lee et al., Direct Imaging of Soft-Hard Interfaces Enabled by Graphene, Nano Lett. 9 (2009) 3365.

2 nm

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SEM Cathodoluminescence (1)

24X. Zhou et al., The Origin of Green Emission of ZnO Microcrystallites: Surface-Dependent Light Emission Studied by Cathodoluminescence, J. Phys. Chem. C 111 (2007) 12091.

SEM Cathodoluminescence (2)

25H. Xue, Probing the strain effect on near band edge emission of a curved ZnO nanowire via spatially resolved cathodoluminescence, Nanotech. 21 (2010) 215701.

Scanning Probe Microscopy(STM, AFM, etc)

26Veeco Instruments, Application Note AN48.

Chemical Force Microscopy

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Y. Sugimoto et al., Chemical identification of individual surface atoms by atomic force microscopy, Nature 446 (2007) 64.

Near-Field Scanning Optical Microscopy (NSOM)

28F. de Lange et al., Cell biology beyond the diffraction limit: near-field scanning optical microscopy, J. Cell Sci. 114 (2001) 4153.

L. Zhou et al., Direct near-field optical imaging of UV bowtie nanoantennas, Optics Express 17 (2009) 20301.

Dynamics

Quantum dots and FRET

Localized emitter structural/proximity effects surroundings effects phonon spectrum changes

Plasmonics

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I review for J. Lumin. too!

Quantum Dot Absorbance

L. Brus, Chemical Approaches to Seminconductor Nanocrystals, J. Phys. Chem. Solids 59 (1998) 459.30

Quantum Dot Luminescence

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A.L. Rogach, Energy transfer with semiconductor nanocrystals, J. Mater. Chem. (2009) 1208-1221.

M. Jones, G.D. Scholes, On the use of time-resolved photoluminescence as a probe of nanocrystal photoexcitation dynamics, J. Mater. Chem. 20 (2010) 3533.

Fluorescence Resonant Energy Transfer (FRET) donor/acceptor

spectral overlap distance

dependence 1/d6

dipole-dipole orientation

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A.L. Rogach, Energy transfer with semiconductor nanocrystals, J. Mater. Chem. (2009) 1208-1221.

Quantum dot FRET

33A.L. Rogach, Energy transfer with semiconductor nanocrystals, J. Mater. Chem. (2009) 1208-1221.

Localized Emitter in a Nanocomposite

crystallinity and defect concentration

dopant concentration

metastable/disordered structure dopant concentration and distribution surface proximity surroundings effects size-dependent phonon effects

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12-nm fcc Ni; P.M. Derlet et al., Phys. Rev. Lett. 87 (2001) 205501.

Surroundings Effect (spontaneous transition rate)

7-nm Eu3+:Y2O3

dispersed in different media

Line assumes 0.23 filling factor

35R.S. Meltzer, Dependence of fluorescence lifetimes of Y2O3:Eu3+ nanoparticles on the surrounding medium, Phys. Rev. B 60 (1999) R14012.

Size Effects on Nonradiative Rates

dopant segregation proximity to defects/surface electron-phonon interaction phonon density of states (PDOS)

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Energy Flow in a Nanocomposite

J. Yang et al., Mesoporous Silica Encapsulating Upconversion Luminescence Rare-Earth Fluoride Nanorods for Secondary Excitation, Langmuir 26 (2010) 8850.

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Size-Dependent PDOS

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G. Liu, X. Chen, Spectroscopic properties of lanthanides in nanomaterials, in Handbook on the Physics and Chemistry of Rare Earths, vol. 37, K.A. Gschneidner, Jr., J.-C.G. Bünzli, V.K. Pecharsky, Eds., (2007).

Plasmonics

39X. Huang, S. Neretina, M.A. El-Sayed, Gold Nanorods: From Synthesis and Properties to Biological and Biomedical Applications, Adv. Mater. 21 (2009) 4880.

Plasmonics

“A glance through the recent literature reveals a substantial interest in the physics of minute metal particles.”

J. Appl. Phys., 47 (1976) 2200.40

M. Fleischmann, P.J. Hendra A.J. McQuillan, Raman spectra of pyridine adsorbed at a silver electrode, Chem. Phys. Lett. 26 (1974) 163-166.

Nano Lett. 10(3) 2010

Composite Au Nanostructures

for Fluorescence Studies in Visible Light Nanoassembled Plasmonic-Photonic Hybrid Cavity for Tailored

Light-Matter Coupling Two-Dimensional Quasistatic Stationary Short Range Surface

Plasmons in Flat Nanoprisms Drude Relaxation Rate in Grained Gold Nanoantennas LSPR Study of the Kinetics of the Liquid−Solid Phase Transition in

Sn Nanoparticles Trapping and Sensing 10 nm Metal Nanoparticles Using Plasmonic

Dipole Antennas

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Energy Transfer Distance Dependence

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M. Malicki, et al., Excited-state dynamics and dye–dye interactions in dye-coated gold nanoparticles with varying alkyl spacer lengths, Phys. Chem. Chem. Phys., 12 (2010) 6267.

Size Dependence

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J. Zhang, Y. Fu, J.R. Lakowicz, Luminescent Silica Core/Silver Shell Encapsulated with Eu(III) Complex, J. Phys. Chem. C 113 (2009) 19404.

Fluorophore Engineering

44Y. Fu, J.R. Lakowicz, Enhanced Single-Molecule Detection using Porous Silver Membrane, J. Phys. Chem. C 114 (2010) 7492.

Single Molecule Spectroscopy

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S. Kuhn, U. Hakanson, L. Rogobete, and V. Sandoghdar, Enhancement of Single-Molecule Fluorescence Using a Gold Nanoparticle as an Optical Nanoantenna, Phys. Rev. Lett. 97 (2006) 017402.

Summary

The Future

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Future

More precise control over size, proximity, and complexity in nanostructures

<100 nm resolution in optical imaging methods 3-D nanoscale imaging Engineered excited-state

dynamics The unexpected

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C. L. Degen et al., Nanoscale magnetic resonance imaging, PNAS 106 (2009) 1313.

There's Plenty of Room at the Bottom:An Invitation to Enter a New Field of PhysicsRichard Feynman, 1959.

...possible (I think) for a physicist to synthesize any chemical substance that the chemist writes down. Give the orders and the physicist synthesizes it. How? Put the atoms down where the chemist says, and so you make the substance. The problems of chemistry and biology can be greatly helped if our ability to see what we are doing, and to do things on an atomic level, is ultimately developed–a development which I think cannot be avoided.

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Thanks!

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