Nanophotonics

Week 8

November 16, 2007

Rare earth and quantum dot emitters

H He

Li Be B C N O F Ne

Na Mg Al Si P S Cl Ar

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

Fr Ra Ac Rf Db Sg Bh Hs Mt Uun Uuu Uub

Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

La3+: [Xe] 4f n n=1-14 ….4f n 5s2 5p6

Optical doping with lanthanide ions

Energy levels of lanthanide ions

1.5 µm

Egap(Si)

Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Europium protects the euro

J.F. Suyver, A. Meijerink (UU)

Lanthanide bar codes

Dejneka, PNAS 100, (2003)

                                                                                           

                                                                                                                                                              

H He

Li Be B C N O F Ne

Na Mg Al Si P S Cl Ar

K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr

Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe

Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn

Fr Ra Ac Rf Db Sg Bh Hs Mt Uun Uuu Uub

Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu

Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

La3+: [Xe] 4f n n=1-14 ….4f n 5s2 5p6

Optical doping with lanthanide ions

Chemistry (outer-shell behavior) is similar

A. Polman et al., Appl. Phys. Lett. 62, 507 (1993), J.S. Custer et al., J. Appl. Phys. 75, 2809 (1994)  

Erbium Prasaeodymium

Silica optical fiber transmission spectrum

1012 Hz

1.3 m

1.55 m

Miya et al., Electron. Lett. 15, 108 (1979)

wavelength vs. time division multiplexing:WDM

Erbium transition at 1.5 m

Er absorption and emission cross sections

absorptionemission

G.N. van den Hoven et al. Appl. Opt. 36, 3338 (1997)  

Erbium photoluminescence in various silicate glasses

Wtot=Wrad+CEr-Er[Er][OH]

A. Polman, J. Appl. Phys. 82, 1 (1997)

EXAFS

Local structure around Er in silicate glasses

M.A. Marcus et al., J. of Non-Cryst. Solids 136, 260 (1991)

Planar optical waveguide

Si

high index low index

Waveguide core materials:

• silica glass• Al2O3, Si3N4, ….• polymer• silicon

Photonic integrated circuits on silicon

1 mm

SiO2/Al2O3/SiO2/Si

Al2O3 technology by M.K. Smit et al., TUD

The world’s smallest erbium-doped optical amplifier

1.53 m signal, 1.48 m pump, 10 mW, gain: 2.3 dB

Waveguide spiral size: 1 mm2

minimum bending radius > 50 m

Appl. Phys. Lett. 68, 1886 (1996)

From a FOM prototype to a 40 M$ company …

SymmorphixSunnyvaleCA, USA

1.5 µm microcavity mode imaged through green upconversion

2 MeV Er implantation, 0.35 at.%, + 800 °C anneal

T.J. Kippenberg et al.

Nanophotonics

Week 8

November 16, 2007

Rare earth and quantum dot emitters

-2

-1

0

1

2

3

4

++++++

- - - - - - -

[100] X

E (

eV

)

Wave Vector

Indirect bandstructure

Silicon is an inefficient light emitter

Si:Er light-emitting diode

G. Franzó et al., Appl. Phys. Lett. 64, 2235 (1994),B. Zheng et al., Appl. Phys. Lett. 64, 2842 (1994)

Er, O doped c-Si

• 5 m SiO2

• 165 keV Si, 1.71017 cm-2

• anneal: 1100 C nanocrystals: 3-5 nm

Silicon quantum dots: particles in a box

106 104 102 100 98

2SiO

600oC

800oC

1000oC

1100oC

Bulk Si

400oC

As-Imp.

Thermal

Inte

nsity

(A

rb. U

nits

)

Binding Energy (eV)

X-ray Photo-electron spectroscopy

Luminescence spectrum depends on Si concentration red-shift for larger nanocrystal size

50 keV Si, 1100 oC/10 min, 500 eV D, 31015 cm-2

600 700 800 9000.0

0.2

0.4

0.6

0.8

1.0 2e16 Si/cm2

4e16 Si/cm2

6e16 Si/cm2

PL

Sig

nal (

a.u.

)

Wavelength (nm)

E = 300-340 meV

Bulk Sibandgap1100 nm

600 700 800 900 1000 1100 12000.0

0.2

0.4

0.6

0.8

1.0

EGAP Bulk Si

0 min 3 min 10 min 15 min 20 min 25 min 30 min

PL

Sig

nal (

a.u.

)

Wavelength (nm)

Si + O2 Si + SiO2

Shrinking Si quantum dots by oxidation: blue shift

E = 300-400 meV

5 nm

PbS: rock-salt structure

Nearly spherical shape, crystal facetsNearly spherical shape, crystal facets

Compound semiconductor quantum dots: PbS

Modified slide from D. Vanmaekelbergh

CdSe: wurtzite

Modified slide from D. Vanmaekelbergh

Compound semiconductor quantum dots: CdSe

Modified slide from D. Vanmaekelbergh

Luminescence from compound semiconductor quantum dots

Class topics

1. Resonances and refractive index2. Nanoparticle scattering3. Surface plasmon polaritons4. Ornstein Laboratory excursion5. Photonic crystals6. AMOLF lab tour7. Local density of optical states8. Rare earth ions and quantum dots9. Microresonators10. Philips excursion11. NANONED Conference12. Near field optics13. Metamaterials14. p.m.15. Nanophotonics Student Symposium