HK , May, 2010

HK, May, 2010

Exciton-plasmom interactionExciton-plasmom interactionand eand enhanced energy transfer nhanced energy transfer

in active plasmonic nanosystemin active plasmonic nanosystem

Qu-Quan WANGQu-Quan WANG(( 王取泉王取泉 ))

qqwang@whu.edu.cnWuhan University

activeplasmonic

system

semiconductor QDs(quantum SWAP, dephasing, spin)

spaser

rare-earth NCs(dopant-control phase, ET)

antennaAg nanorod(nonlinear FOM)

Au nanowire(avalanche MPL)

Ag nanoring(focusing, SP amplification)

Optical nanoemitters

(sources)

Metallic nanostructures

(plasmons)

Au-Ag nanocomplex(plasmon Fano resonances)

Our interests:

OutlineOutline

Brief introductionBrief introduction一 , 掺杂调控纳光子发射体的光学特性 1.1. Mn 掺杂半导体量子点的光学特性 1.2. Ln 掺杂调控 NaYF4 稀土纳米晶的晶相和上转换发射效

率二 , 金属纳米结构中表面等离激元 Fano 干涉效应 2.1. Au-Ag 异质纳米棒中双 Fano 共振效应 2.2. 明 - 暗等离激元能量转移与光调制效应三 , 金属表面等离激元与纳光子发射体相互作用 3.1. Ag 纳米颗粒双频天线增强量子点之间非辐射能量转移 3.2. Ag 纳米线阵列增强量子点之间辐射能量转移 3.3. Ag 纳米环可控增强量子点发射与表面等离激元放大 SummarySummary

* Brief introduction* Brief introduction Spaser from two nanosystems: Dye molecule – Au nanoparticle CdS nanorod – Ag thin film

M. A. Noginov et al., Nature 460, 1110 (2009).

Spaser from Au nanoparticles with dye molecules

The activators are dye nanoemitters

Rupert F. Oulton et al., doi:10.1038/nature08364 (2009)

Spaser from Ag thin film with CdS nanowire

The activator is CdS nanowire.

一 , 掺杂调控纳光子发射体的光学特性 1.1 Mn 掺杂半导体量子点的光学特性 1.2 Ln 掺杂调控 NaYF4 稀土纳米晶的晶相和上转换发射

效率

1.1. Mn 掺杂半导体量子点的光学特性ZnSe:Mn/CdSe反核壳量子点中激子极化和存储

磁共振精细结构（ EPR ）

Mn2+

PL

(Exciton)

Exciton

14 T

|0

|g

|1

CdSeMn2+

ZnSe

ZnSe:Mn/CdSe

共振转移

Mn(2+) PL和激子PL

激发和发射谱的差别

14 T

Mn(2+) PL和激子 PL发射动力学的差别

MnMn 延长延长激子激子 PLPL 寿命寿命

MnMn 增强增强 激子激子 PLPL 强度强度

Appl. Phys. Lett. 96, 123104 (2010)

1.2. Ln 掺杂调控 NaYF4 稀土纳米晶的晶相和上转换发射效率

Nano Res. 3, 51 (2010)

我们的文章发表在 Nano Research 1 月份的封面上，优点是生物相容性2 月份 Nature 上也报道了调控晶相的文章，但没有生物相容性

二 , 金属纳米结构中表面等离激元 Fano 干涉效应 2.1. Au-Ag 异质纳米棒中双 Fano 共振效应 2.2. 明 - 暗等离激元能量转移与光调制效应

2.1 Au-Ag 异质纳米棒中双 Fano 共振效应

Energy transfer between Au and Ag

692 nm

712 nm

786 nm

Au Ag

Appl. Phys. Lett. 96, 131113 (2010)

2.2 明 - 暗等离激元能量转移与光调制效应

Appl. Phys. Lett. 96, 043113 (2010)

三 , 金属表面等离激元与纳光子发射体相互作用 3.1. Ag 纳米颗粒双频天线增强量子点之间非辐射能量转移 3.2. Ag 纳米线阵列增强量子点之间辐射能量转移 3.3. Ag 纳米环可控增强量子点发射与表面等离激元放大

3.3.11.. Plasmon-enhanced nonradiative ET Plasmon-enhanced nonradiative ET between SQDs by using Ag NPsbetween SQDs by using Ag NPs

Physics process: Plasmon-enhanced FRET

ET distance: < 10 nm

Donor/acceptors: SQDs in mononlayer film

Tool: large Ag NPs

Physics effect: Dual-frequency nanoantenna

Dipole and quadrupole SPRs of Ag NPs

3

4

3

4)10(

30

4

3

1

/)()5/2(1

3

4)(

3Ag

3

2/3SiO2

2

2

2Ag

SiO2Ag

2

SiO2Ag

SiO2

22Ag SiO2Ag

23Ag

Ri

R

RR

）（）（

）（Size-dependent polarizability of dipole SPRs of Ag NPs:

receivingemitting

by single-frequency nanoantenna by dual-frequency nanoantenna

W/O nanoantennadonor acceptor

without Ag NPs

FRET dynamics from donor to acceptor

with Ag NPs

Appl. Phys. Lett. 96, 043106 (2010)

FRET efficiency

single

frequency

dual-frequency

antenna

3.3.22. . Plasmon-mediated radiative energy transfer Plasmon-mediated radiative energy transfer between semiconductor quantum dotsbetween semiconductor quantum dots

acceptor

SQDs

PLb

laser

donor

SQDs

E

Ag NR array

Physics process: SPP-mediated radiative ET

ET distance: ~ 500 nm

Donor/acceptors: SQDs / SQDs

Tool: Ag NR array

Physics effects: subwavelength imaging(near-field SPP coupling, resonant transmission, subwavelength focusing)

50 nm

130 nm

220 nm

45 nm

130 nm

210 nm

Half-wave plasmon resonances in Ag NR arrays

Ez - polarized point source

Ey - polarized point source

m = 1

m = 3

m = 2

L = mSP/2

3.3. Plasmon amplifications in Ag nanoring3.3. Plasmon amplifications in Ag nanoring

* * Tunable PL enhancement (E)Tunable PL enhancement (E)

* Plasmon amplifications (T)* Plasmon amplifications (T)

C

E

[001]t[110]

SinglyTwinnedCrystal (19.5)

D

BA

Synthesis of singly-twinned Ag nanoring

CdSe SQDs PL enhanced by a Ag nanoring

A

x

PLLaserin

y

Singlenanoring

Monolayer SQDs

60 65 70 75 80 851

2

3

4

5

6

7

8

Rel

ativ

e en

han

cing

fact

or

Incidence angle in

( O)

E

H.M.Gong, et al., Adv.Funct.Mater.19, 298(2009)

a

1k

2m

c

2k1k

b

2k

Tunable “hot spots”

Time-resolved Photoluminescence

pure SQDs

SQDs + nanoring

0 2 4 6 8

5000

6000

7000

8000

Ph

oto

n co

unt

s (a

.u.)

Time delay d(ns)

Plasmon amplification in Ag nanoring

Opt. Express 19, 289 (2010)

Summary

* * Ag nanoparticles Ag nanoparticles enhance nonradiative enhance nonradiative ET efficiently via dual-frequency antenna ET efficiently via dual-frequency antenna effect effect

* Ag nanoring has tunable “hot spot” and * Ag nanoring has tunable “hot spot” and could be used in plasmon amplificationscould be used in plasmon amplifications

* Multiphoton luminescence from the * Multiphoton luminescence from the hybrid of SQDs and AgNRs are tunablehybrid of SQDs and AgNRs are tunable

Acknowledgement

Profs. Q. K. Xue, J. Zi, J. F. Jia Profs. Z. Y. Zhang, Q. H. Gong Drs. X. Y. Shan, Q. Zhang Drs. L. Zhou, H. M. Gong, S. Xiao

X. F. Yu, X. R. Su, Z. K. Zhou

Thank you!