materials for infrared and terahertz plasmonics · plasmonics 14 – may - 2014 ph.d. candidate:...

Materials for Infrared and Terahertz Plasmonics

14 – May - 2014

Ph.D. Candidate: Fausto D'ApuzzoSupervisor: Prof. Stefano Lupi

Outline

- Introduction to Plasmonics - Need for New Materials

- Indium Tin Oxide- Nanoporous Graphene - Comparison to Noble metals- Conclusions

Fausto D'Apuzzo – PhD dissertation 27 Oct 2015

The Physics of Surface Plasmons


Definition:Surface Plasmons are the collective oscillations of the electron plasma at a metal-dielectric interface.

The Physics of Surface Plasmons


Definition:Surface Plasmons are the collective oscillations of the electron plasma at a metal-dielectric interface.

Properties:● Hybrid Nature: both electromagnetic

and electronic character● Energy confinement (waveguiding)● Field Enhancement (sensing)

Energy dispersion of SP

Light Dispersion



Light Dispersion


Surface Plasmons


Light Dispersion

Surface Plasmons


Photonic Regime:Modes very similar to free radiation


Light Dispersion

Surface Plasmons



Plasmonic Regime:Higher wavevector--> plasmonic compression




Light Dispersion

Surface Plasmons

Light squeezing


Need for new plasmonic materials

Desired Properties:

● Plasma Frequency: THz, MIR, NIR, VIS



Desired Properties:

● Plasma Frequency: THz, MIR, NIR, VIS● Tunability:

● Fabrication process: (nanostructure, n)● Dynamical: external stimuli (B, T, E)



Desired Properties:

Materials:

Noble Metals Semiconductors Graphene Au, Ag, Al Transparent conductive Oxides Topological Insulators





Desired Properties:

Materials:




V



Desired Properties:

Materials:




● Others: small losses, transparency, flexibility, 2D, 1D

V


New Materials for Infrared Plasmonics

Indium Tin Oxide (ITO)Hole array

Nanoporous Graphene (NPG)





● What is the advantage of plasmonic ITO?


Transparent Conductive Oxides (TCO)

Physical and Optical Properties:● Transparent to visible light● Large energy gaps (3 eV)


Physical and Optical Properties:● Transparent to visible light● Large energy gaps (3 eV)● Infrared Conductivity


Physical and Optical Properties:● Transparent to visible light● Infrared Conductivity● Large energy gaps (3 eV)

Indium Tin Oxide (ITO) Sn:In2O3● Film Thickness: 170 nm● Carrier density n≈5.5 1020 cm-3.● Plasma frequency: Infrared





1 2

1

2





1 2

1

2

TunableDrude


Plasmons in ITO hole arrays

x2

x2


4 µm


x2

x2


4 µm

[2] F. D'Apuzzo, et al. Plasmonics (2014)

[1] O. Limaj, F. D'Apuzzo, et al., JPPC (2013)


x2

x2


4 µm


[2] O. Limaj, F. D'Apuzzo, et al., JPPC (2013)

Advantages of ITO:● Plasmonic regime at Mid-Infrared

frequencies without demanding lithography

[1] O. Muskens, et al., ACS phot. 2, 606 (2015)


x2

x2


4 µm

Advantages of ITO:● Plasmonic regime at Mid-Infrared

frequencies without demanding lithography

● SEIRA effect visible in d=2 μm


[2] O. Limaj, F. D'Apuzzo, et al., JPPC (2013) [1] O. Muskens, et al., ACS phot. 2, 606 (2015)




● Plasmonic effects in the Mid-Infrared without demanding nanofabrication







● Any plasmonic properties?● Are the unique properties of

massless Dirac carriers preserved in NPG?


Fabrication Process of Nanoporous Graphene (NPG)

Y. Ito et al., Angew. Chem., 2014, 126, 19

Y. Ito et al., Adv. Mat. 2014, 26, 4145

Nanoporous Ni

Chemical removal of Ni-substrate

+

Leatching


1 2

3

4

Infrared Conductivity properties

Metal



Metal


Spectral features:● Interband transitions


Metal



● Plasmonic absorption


Metal



● Plasmonic absorption

● Pauli-Blocking minimum

Spectra are in good agreement with analytical models for Graphene, especially if Fermi Energy inhomogeneity is taken into account.

Pore-size dependence as in 2D plasmons



MetalMetal1 um



MetalMetal1 um

Fausto D'Apuzzo – PhD dissertation 27 Oct 2015[2] J. F. Garcia de Abajo, ACS Nano, 7, 2388 (2013)

[1] S. Das Sarma, PRL, 102, 206412 (2009)


MetalMetal1 um

Pore-size dependence:● Geometrical dependence is

compatible with 2D plasmons [1]● Frequencies are compatible with

graphene discs [2] riscaled by Fermi Energy ratio = (70 meV/600 meV)

[2] J. F. Garcia de Abajo, ACS Nano, 7, 2388 (2013)

[1] S. Das Sarma, PRL, 102, 206412 (2009)



MetalMetal1 um

Pore-size dependence:● Geometrical dependence is

compatible with 2D plasmons [1]● Frequencies are compatible with

graphene discs [2] riscaled by Fermi Energy ratio = (70 meV/600 meV)


[1] S. Das Sarma, PRL, 102, 206412 (2009)


2D!!! Massless?

EF dependence of plasmons in NPG

Metal

500 nm

Fixed size200 nm



Metal

500 nm

Fermi energy dependence:● Plasmon behavior for increasing Fermi

energy is compatible with Dirac carriers:

● Frequencies are quantitatively comparable with those of graphene discs [1] of diameter between 100-200 nm.

ω pl∝√EF

Fixed size200 nm


Magnetoplasmons in NPG


B

E



B

E

B



B

E

B

NPG Magnetoplasmon:● Exhibits the behavior characteristic

of relativistic particles:




of relativistic particles:

B

E




of relativistic particles:Experimental data compatible with model for relativistic carriers.

3D-NPG preserves Dirac properties of 2D monolayer graphene.

vF= 9.4 105 m/s

B

E

Comparative plasmonic dispersion


Comparative plasmonic dispersion

Fausto D'Apuzzo – PhD dissertation 27 Oct 2015[1] M. Autore, F. D'Apuzzo, et al., Adv. Opt. Mat., 3, 1257 (2015)

Conclusions and Future work


Conclusions● ITO films can exhibit strong plasmonic effects in the Mid-

Infrared already with patterns of 2 micron periodicity

● 3-dimensional Nanoporous Graphene (NPG) exhibits THz and Mid-Infrared Plasmons, tunable with chemical doping, pore-size and external magnetic field.

● The 3-dimensional configuration preserves the unique characteristics of 2D graphene plasmons.

Future work: ● Infrared plasmons both in ITO and in NPG can be

investigated by near-field imagining at the nanoscale by tip-enhanced nanospectroscopy. ● During post-doc @ LBNL,

ALS-Synchrotron, Berkeley, CA

Publications


Pubblications 13. Mid-Infrared Plasmonic excitation in Indium Tin Oxide micro-hole arrays, Article in preparation (2015) 12. Terahertz and Mid-Infrared Plasmons in Three-dimensional Nanoporous Graphene, Article in preparation (2015) 11. Interaction and Dynamics of Ionic Liquids Based on Choline and Amino-Acids Anions, Journal of Chemical Physics 142, 234502 (2015) 10. Observation of Magnetoplasmons in Bi2Se3 Topological Insulator, ACS Photonics 2, 1231 (2015) 9. Optical Properties of V2O3 in its Whole Phase Diagram, Phys. Rev. B, 91, 155133 (2015) 8. Plasmon-phonon Interactions in Topological Insulator Microrings Advanced Optical Materials, 3, 1257 (2015) 7. Resonating Terahertz Response of Periodic Arrays of Subwavelength Apertures, Plasmonics DOI: 10.1007/s11468-014- 9775-3 6. Optical Conductivity of V4O7 across its Metal-Insulator Transition, Phys. Rev. B, 09, 115149 (2014) 5. Mid-Infrared Surface Plasmon Polariton Sensors Resonant with the Vibrational Modes of Phospholipid Layers, Journal of hysical Chemistry C, 117, 19119 (2013)

Conference Proceedings4. Terahertz Plasmonic Excitations in Bi2Se3 Topological Insulator, Organization: Metamaterials 20143. Differential Fano Interference Spectroscopy of Subwavelength Hole Arrays for Mid-Infrared Mass sensors, SPIE OPTO. - 20132. Dark and Bright Surface Plasmon Resonances of Metal Meshes for Mid-Infrared Sensing at the Nanoscale, IRMMW-THz (2012) 37th International Conference - (2012)

Book Chapters1. Terahertz and Infrared Plasmonics with unconventional materials, Publisher: Encyclopedia of Nanotechnology, Springer (2015)

Conferences contributions


Invited Talks9. 2015 Title: "Plasmons in 3D-Nanoporous Graphene" World Congress of Advanced Materials 2015, BIT Congress Inc. - Chongqing (China)

Oral Contributions8. "THz and Mid-Infrared Plasmonic Excitation in 3D Nanoporous Graphene" Imaginano 2015 - Bilbao (Spain)7. "Dirac Plasmons of Topological Insulators" Plasmonica 2014 - University of Rome ’Sapienza’, Rome (Italy)6. "Terahertz Plasmonics of Periodic Arrays of Subwavelength Apertures" 4th EOS Topical Meeting on Terahertz Science and Technology (TST 2014), EOS - Camogli (Italy)5. Plasmonica 2013 - Politecnico di Milano, Milan (Italy)4. International School of Atomic and Molecular Spectroscopy, Nano-structures for Optics - Erice (Italy)

Poster Contributions3. "THz and Mid-Infrared Plasmonic Excitation in 3D Nanoporous Graphene" 8th International Workshop on Infrared Microscopy and Spectroscopy using Accelerator based Sources - WIRMS 2015 - Oct 2015 - New York (USA)2. "THz and Mid-Infrared Plasmonic Excitation in 3D Nanoporous Graphene" Imaginano 2015 - Bilbao (Spain)1. "THz and Mid-Infrared Hole Arrays for Plasmonic Bio-sensing" 6th Mediterranean Conference on Nano-Photonics MediNano-6 - Lyon (France)

AwknowledgementsTeraLabStefano LupiOdeta LimajMarta AutoreFlavio GiorgianniAndrea StaraceAlba Rosa PiacentiMaddalena Daniele

Istituto Italiano di TecnologiaEnzo M. Di FabrizioPatrizio CandeloroMarco EspositoAlessandro CannavaleAndrea TomaRemo Proietti

Thanks for your attention!

Laboratorio di biofisicaFederico BordiFabio DomeniciSimona Sennato

Tohoku UniversityMingwey ChenYoshikatzu Ito

Synchrotrons and other Labs:

materials for infrared and terahertz plasmonics · plasmonics 14 – may - 2014 ph.d. candidate:...

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