HK, May, 2010 Exciton-plasmom interaction and enhanced energy transfer in active plasmonic nanosystem Qu-Quan WANG ( 王取泉 ) Wuhan University

active plasmonic system semiconductor QDs (quantum SWAP, dephasing, spin) spaser rare-earth NCs (dopant-control phase, ET) antenna Ag 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:

Outline Brief introduction Brief 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 NaYF 4 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 Summary Summary

* 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: /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 ） Mn 2+ PL (Exciton) Exciton |0  |g|g |1  CdSe Mn 2+ ZnSe ZnSe:Mn/CdSe 共振转移

Mn(2+) PL 和激子 PL 激发和发射谱的差别 Mn(2+) PL 和激子 PL 发射动力学的差别

Mn 延长 激子 PL 寿命 Mn 增强 Mn 增强 激子 PL 激子 PL 强度 强度 Appl. Phys. Lett. 96, (2010)

1.2. Ln 掺杂调控 NaYF 4 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, (2010)

2.2 明 - 暗等离激元能量转移与光调制效应

Appl. Phys. Lett. 96, (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

3.1. Plasmon-enhanced nonradiative ET between SQDs by using Ag NPs between 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 Size-dependent polarizability of dipole SPRs of Ag NPs: receiving emitting

by single-frequency nanoantenna by dual-frequency nanoantenna W/O nanoantenna donor acceptor

without Ag NPs FRET dynamics from donor to acceptor with Ag NPs

Appl. Phys. Lett. 96, (2010) FRET efficiency single frequency dual-frequency antenna

3.2. Plasmon-mediated radiative energy transfer between semiconductor quantum dots acceptor SQDs PL bb 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 E z - polarized point source E y - polarized point source m = 1 m = 3 m = 2 L = m SP /2

3.3. Plasmon amplifications in Ag nanoring * Tunable PL enhancement (E) * Tunable PL enhancement (E) * Plasmon amplifications (T) * Plasmon amplifications (T)

C E Singly Twinned Crystal (19.5  ) D BA Synthesis of singly-twinned Ag nanoring

CdSe SQDs PL enhanced by a Ag nanoring A x PLPL Laser  in y Single nanoring Monolayer SQDs

H.M.Gong, et al., Adv.Funct.Mater.19, 298(2009) a 2m2m c b Tunable “hot spots” Time-resolved Photoluminescence

Plasmon amplification in Ag nanoring Opt. Express 19, 289 (2010)

Summary * Ag nanoparticles enhance nonradiative ET efficiently via dual-frequency antenna effect * Ag nanoring has tunable “hot spot” and could be used in plasmon amplifications * Multiphoton luminescence from the hybrid 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!