Transcript Ag nanoring
Exciton-plasmom interaction and enhanced energy transfer in active plasmonic nanosystem Qu-Quan WANG (王取泉) [email protected] Wuhan University HK, May, 2010 Our interests: semiconductor QDs Optical nanoemitters (sources) (quantum SWAP, dephasing, spin) rare-earth NCs (dopant-control phase, ET) active antenna plasmonic spaser system Metallic nanostructures (plasmons) Ag nanorod (nonlinear FOM) Au nanowire (avalanche MPL) Ag nanoring (focusing, SP amplification) Au-Ag nanocomplex (plasmon Fano resonances) Outline 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 Summary * Brief introduction Spaser from two nanosystems: Dye molecule – Au nanoparticle CdS nanorod – Ag thin film Spaser from Au nanoparticles with dye molecules M. A. Noginov et al., Nature 460, 1110 (2009). The activators are dye nanoemitters Spaser from Ag thin film with CdS nanowire Rupert F. Oulton et al., doi:10.1038/nature08364 (2009) 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 ZnSe:Mn/CdSe 磁共振精细结构 （EPR） ZnSe Mn2+ |1 CdSe Exciton Mn2+ 4 |g |0 T1 共振转移 PL (Exciton) Mn(2+) PL和激子PL 激发和发射谱的差别 4 T1 Mn(2+) PL和激子PL 发射动力学的差别 Mn增强 激子PL 强度 Mn延长 激子PL寿命 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 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 Nano Res. 3, 51 (2010) 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 Au Ag 692 nm 712 nm 786 nm 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 3.1. Plasmon-enhanced nonradiative ET between SQDs by using Ag NPs Physics process: ET distance: Donor/acceptors: Tool: Plasmon-enhanced FRET < 10 nm SQDs in mononlayer film large Ag NPs Physics effect: Dual-frequency nanoantenna Dipole and quadrupole SPRs of Ag NPs receiving emitting Size-dependent polarizability of dipole SPRs of Ag NPs: ( ) 3 4RAg 3 2 1 (2 / 5) 2 ( Ag（） SiO2 ) RAg / 2 1 SiO2 3 （） Ag SiO2 2 3 2 3/ 2 4 2 RAg 4 R 4 Ag SiO2 ( Ag（） 10 SiO2 ) 2 i 3 30 3 3 W/O nanoantenna donor by single-frequency nanoantenna acceptor by dual-frequency nanoantenna FRET dynamics from donor to acceptor without Ag NPs with Ag NPs FRET efficiency single frequency dual-frequency antenna Appl. Phys. Lett. 96, 043106 (2010) 3.2. Plasmon-mediated radiative energy transfer between semiconductor quantum dots laser E b PL Ag NR array donor SQDs acceptor SQDs Physics process: ET distance: Donor/acceptors: Tool: Physics effects: SPP-mediated radiative ET ~ 500 nm SQDs / SQDs Ag NR array subwavelength imaging (near-field SPP coupling, resonant transmission, subwavelength focusing) Half-wave plasmon resonances in Ag NR arrays Ez - polarized point source Ey - polarized point source L = mSP/2 m=1 m=2 m=3 50 nm 45 nm 130 nm 220 nm 130 nm 210 nm 3.3. Plasmon amplifications in Ag nanoring * Tunable PL enhancement (E) * Plasmon amplifications (T) Synthesis of singly-twinned Ag nanoring A B C D E Singly Twinned Crystal (19.5) [110] [001]t CdSe SQDs PL enhanced by a Ag nanoring A Laser in P L y Monolayer SQDs x Single nanoring Relative enhancing factor E 8 7 6 5 4 3 2 1 60 65 70 75 80 O Incidence angle in( ) 85 a b k1 k2 Time-resolved Photoluminescence c k2 2m Tunable “hot spots” Photon counts (a.u.) k1 8000 pure SQDs 7000 6000 SQDs + nanoring 5000 0 2 4 6 Time delay td (ns) H.M.Gong, et al., Adv.Funct.Mater.19, 298(2009) 8 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!