SurfacePlasmon Resonances - PowerPoint PPT Presentation

Title: SurfacePlasmon Resonances


1
Surface-Plasmon Resonances in Indium Nitride
with Metal-Enriched Nanoparticles
Tatiana Shubina
Ioffe Physico-Technical Institute St. Petersburg,
Russia
2
Outline

• Introduction. Plasmonics as a novel branch of
  semiconductor physics
• Mie resonances. Surface plasmons
• Enhanced PL near metal nano-clusters. Basic
  emission properties
• Perspectives of InNIn composites

3
Optical plasma resonances
studied more than a century
Drude metals in vacuum
tmin - 30 ?
- plasmons
10x100 ?
4
Mie resonances
The resonances in light absorption and scattering
due to the interaction of an electromagnetic
field with multipolar electron excitations in
metallic clusters
G. Mie, Ann. Phys. (1908)
1st
2nd

5
The Mie extinction cross-section
e
e
R
s y e , em , R
em
R
em
Small spheres

• Strong dependence on ? of a medium
• The metal Re?m should be negative for a
  resonance

Re?m of In is negative
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Maxwell-Garnett approximation
J.C. Maxwell-Garnett, Philos. Trans. R. Soc.
Lond. (1904)
Effective medium with ellipsoidal clusters
Lm - depolarization factor f - filling factor
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Plasmonics Mordern history

• Application of collective electron excitations at
  a metal/dielectric interface
• Possibilities of light manipulation at
• sub-wavelength dimensions.
• Left-handed materials
• V. G. Veselago, Sov. Usp. Phys. 10
  (1968)
• J. B. Pendry, Phys. Rev. Lett. 85
  (2000).
• Waveguides with sharp corners
• S. A. Maier et. al. Adv. Mater. 13
  (2001)
• Effective light conversion and enhancement

8
Surface-plasmon-enhanced light emitters
K. Okamoto et al., Nature 3, 601 (2004).

• PL in InGaN QWs covered
• by a metal film is 6.8 times more
• intense, due to the coupling of
• recombining carriers with the
• surface plasmons
• The white LED can be brighter
• than conventional lamps

9
Optical/microwave conversion in GaAs with small
metallic As(Er) clusters
The Maxwell-Garnett approximation
As precipitates
IR peak in absorption
/After Herms at al./
GaAsAsEr
/E. R. Brown et al., Phys. Rev. Lett. 90 (2003)/

• A search of new composites with absorption edges
  matching better the wavelengths of standard
  semiconductor lasers

10
Mie Absorption vs In excess
0.35 K
N/In0.85
N/In0.93
N/In1
Phys. Rev. Lett. 92, 117407 (2004)
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The Mie resonance vs InN dielectric functions
0.9eV DF
1.35eV DF
Goldhahn et al. MRS (2003)

• A resonance quenches in an absorbing medium

Phys. Rev. Lett. 93, 269702 (2004)
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Absorption vs filling factor f
Maxwell-Garnett approximation
The 1.35-eV DF

• Absorption tail related to metallic In exists
  even at small concentration

13
Enhanced CL near In nano-clusters
CL
In clusters
Combined CL and BSE images
14
Extremely sharp TDOA IR peak
0.35K
2.7x1018
300K
2.5x1018
0.6x1018
Energy (eV)
Theory / Bechstedt et al. Phys. Stat. sol. (a)
195 (2003)/
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PL excitation
TDOA
a tungsten lamp, 20 K
PL
2.7x1018
PLE

• Sharp PLE edge for the main line - resonance
  nature

2.5x1018

• Different PLE spectra for
• two PL lines

• D EPL-PLE 50 and 200 meV

0.6x1018
Energy (eV)
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Selective excitation of PL
air
InN
selective
sapphire
Eex, eV 0.95 0.8 0.7
MOCVD
PLE

• Drop at 1 eV followed by an increase at 0.7 eV

17
In-plane enhancement of PL intensity
typical
plasmonic
feature
I/IA intensity (a.u.)
Maximal at p polarization, like for
plasmon-related emission
Energy (eV)
18
Instead of conclusion
InN A long chain of puzzles and
perspectives
InN
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Acknowledgements

• B. Monemar, A. Kasic (Linköping University,
  Sweden)
• W. J. Schaff, H. Lu (Cornell University, USA)
• K. S. A. Butcher (Macquarie University,
  Australia)
• H. Amano, I. Akasaki, K. Shimono (Meijo
  University, Japan)
• Q. Guo (Saga University, Japan)
• Kavokin, J. Leymarie, A. Vasson (LASMEA-UMR,
  France)
• O. Briot, B. Gil (Montpellier University,
  France)
• S. Ivanov, P. Kopev, V. Jmerik, V. Vekshin, D.
  Solnyshkov,
• M. M. Glazov, Dr. V. Ratnikov, A. P. Kalvarskii,
  M. Tkachman,
• D. Plotnikov (Ioffe Institute, Russia)

• The RFBR Grant Plasmonic effects in
• metal/semiconductor nanostructures
• The ONRG Grant N00014-05-1-4026