Strong Coupling between ZnO Excitons and Localized Surface Plasmons of Silver Nanoparticles Studied by STEM-EELS.

We investigated the strong coupling between the excitons of ZnO nanowires (NWs) and the localized surface plasmons (LSPs) of individual Ag nanoparticles (NPs) by monochromated electron energy loss spectroscopy (EELS) in an aberration-corrected scanning transmission electron microscopy (STEM) instrument. The EELS results confirmed that the hybridization of the ZnO exciton with the LSPs of the Ag NP created two plexcitons: the lower branch plexcitons (LPs) with a symmetrical dipole distribution and the upper branch plexcitons (UPs) with an antisymmetrical dipole distribution. The spatial maps of the LP and UP excitations reveal the nature of the LSP-exciton interactions. With decreasing size of the Ag NP the peak energies of the LPs and UPs showed a blue-shift and an anticrossing behavior at the ZnO exciton energy was observed. The coupled oscillator model explains the dispersion curve of the plexcitons and a Rabi splitting energy of ∼170 meV was deduced. The high spatial and energy resolution STEM-EELS approach demonstrated in this work is general and can be extended to study the various coupling interactions of a plethora of metal-semiconductor nanocomposite systems.

[1]  Stefan A. Maier,et al.  Quantum Plasmonics , 2016, Proceedings of the IEEE.

[2]  U. Hohenester,et al.  Optical excitations of hybrid metal-semiconductor nanoparticles , 2015 .

[3]  Jorge Bravo-Abad,et al.  Theory of strong coupling between quantum emitters and localized surface plasmons , 2014 .

[4]  P. Batson,et al.  Vibrational spectroscopy in the electron microscope , 2014, Nature.

[5]  X. Bai,et al.  In-situ optical transmission electron microscope study of exciton phonon replicas in ZnO nanowires by cathodoluminescence , 2014 .

[6]  Benxia Li,et al.  Metal/Semiconductor Hybrid Nanostructures for Plasmon‐Enhanced Applications , 2014, Advanced materials.

[7]  P. Mulvaney,et al.  Mapping bright and dark modes in gold nanoparticle chains using electron energy loss spectroscopy. , 2014, Nano letters.

[8]  T. Ellenbogen,et al.  Local excitation of strongly coupled exciton-surface plasmons polaritons by a single nanoantenna , 2014 .

[9]  D. Shen,et al.  Tunable enhancement of exciton emission from MgZnO by hybridized quadrupole plasmons in Ag nanoparticle aggregation , 2014 .

[10]  June-Ki Park,et al.  Plasmon–Exciton Interactions in Hybrid Structures of Au Nanohemispheres and CdS Nanowires for Improved Photoconductive Devices , 2013 .

[11]  Martijn Wubs,et al.  Blueshift of the surface plasmon resonance in silver nanoparticles: substrate effects. , 2013, Optics express.

[12]  H. Kuo,et al.  Effect of the surface-plasmon-exciton coupling and charge transfer process on the photoluminescence of metal-semiconductor nanostructures. , 2013, Nanoscale.

[13]  D. Norton,et al.  Plasmon-exciton hybridization in ZnO quantum-well Al nanodisc heterostructures. , 2012, Nano letters.

[14]  Xue-Wen Chen,et al.  Coherent interaction of light with a metallic structure coupled to a single quantum emitter: from superabsorption to cloaking. , 2012, Physical review letters.

[15]  A. Jauho,et al.  Blueshift of the surface plasmon resonance in silver nanoparticles studied with EELS , 2012, 1210.2535.

[16]  Timothy J. Davis,et al.  Surface plasmon hybridization and exciton coupling , 2012 .

[17]  J. Dionne,et al.  Quantum plasmon resonances of individual metallic nanoparticles , 2012, Nature.

[18]  J. L. Movilla,et al.  Excitonic Resonance in Semiconductor–Metal Nanohybrids , 2011, 1107.2769.

[19]  F J García de Abajo,et al.  Quantum plexcitonics: strongly interacting plasmons and excitons. , 2011, Nano letters.

[20]  Paul S Weiss,et al.  Incident-angle-modulated molecular plasmonic switches: a case of weak exciton-plasmon coupling. , 2011, Nano letters.

[21]  M. Knupfer,et al.  Plasmonic excitations in ZnO/Ag/ZnO multilayer systems: Insight into interface and bulk electronic properties , 2011 .

[22]  Naomi J Halas,et al.  Plexciton dynamics: exciton-plasmon coupling in a J-aggregate-Au nanoshell complex provides a mechanism for nonlinearity. , 2011, Nano letters.

[23]  R. Saija,et al.  Quantum plasmonics with quantum dot-metal nanoparticle molecules: influence of the Fano effect on photon statistics. , 2010, Physical review letters.

[24]  Garnett W. Bryant,et al.  Strongly coupled quantum dot-metal nanoparticle systems: Exciton-induced transparency, discontinuous response, and suppression as driven quantum oscillator effects , 2010 .

[25]  M. Achermann.  Exciton−Plasmon Interactions in Metal−Semiconductor Nanostructures , 2010 .

[26]  P. Nordlander,et al.  The Fano resonance in plasmonic nanostructures and metamaterials. , 2010, Nature materials.

[27]  B. K. Juluri,et al.  Dynamic Tuning of Plasmon–Exciton Coupling in Arrays of Nanodisk–J‐aggregate Complexes , 2010, Advanced materials.

[28]  U. Banin,et al.  Colloidal hybrid nanostructures: a new type of functional materials. , 2010, Angewandte Chemie.

[29]  K. Vernon,et al.  Simple model for the hybridization of surface plasmon resonances in metallic nanoparticles. , 2010, Nano letters.

[30]  Peter Nordlander,et al.  Electron energy-loss spectroscopy (EELS) of surface plasmons in single silver nanoparticles and dimers: influence of beam damage and mapping of dark modes. , 2009, ACS nano.

[31]  D. Richards,et al.  Strong coupling of localized plasmons and molecular excitons in nanostructured silver films , 2009, 0904.2674.

[32]  A. Govorov,et al.  Exciton energy transfer between nanoparticles and nanowires , 2008 .

[33]  G. Bryant,et al.  Optical response of strongly coupled quantum dot-metal nanoparticle systems: double peaked Fano structure and bistability. , 2008, Nano letters.

[34]  Peihong Cheng,et al.  Enhancement of ZnO light emission via coupling with localized surface plasmon of Ag island film , 2008 .

[35]  A. Govorov,et al.  Optical properties of coupled metal-semiconductor and metal-molecule nanocrystal complexes: Role of multipole effects , 2008, 0801.3213.

[36]  D. Lei,et al.  Tunable surface plasmon mediated emission from semiconductors by using metal alloys , 2007 .

[37]  L. Liz‐Marzán,et al.  Mapping surface plasmons on a single metallic nanoparticle , 2007 .

[38]  C. Klingshirn.  ZnO: material, physics and applications. , 2007, Chemphyschem : a European journal of chemical physics and physical chemistry.

[39]  M E Abdelsalam,et al.  Strong coupling between localized plasmons and organic excitons in metal nanovoids. , 2006, Physical review letters.

[40]  N. Kotov,et al.  Theory of plasmon-enhanced Förster energy transfer in optically excited semiconductor and metal nanoparticles , 2006, cond-mat/0612274.

[41]  A. Govorov,et al.  Semiconductor-metal nanoparticle molecules: hybrid excitons and the nonlinear fano effect. , 2006, Physical review letters.

[42]  Tolga Atay,et al.  Large enhancement of fluorescence efficiency from CdSe/ZnS quantum dots induced by resonant coupling to spatially controlled surface plasmons. , 2005, Nano letters.

[43]  H. C. Ong,et al.  Surface-plasmon-mediated emission from metal-capped ZnO thin films , 2005 .

[44]  Gyu-Chul Yi,et al.  ZnO nanorods: synthesis, characterization and applications , 2005 .

[45]  Nicholas A. Kotov,et al.  Bioconjugates of CdTe Nanowires and Au Nanoparticles: Plasmon−Exciton Interactions, Luminescence Enhancement, and Collective Effects , 2004 .

[46]  Takashi Mukai,et al.  Surface-plasmon-enhanced light emitters based on InGaN quantum wells , 2004, Nature materials.

[47]  J. Mugnier,et al.  Strong coupling between surface plasmons and excitons in an organic semiconductor. , 2004, Physical review letters.

[48]  Uri Banin,et al.  Selective Growth of Metal Tips onto Semiconductor Quantum Rods and Tetrapods , 2004, Science.

[49]  Emil Prodan,et al.  Plasmon Hybridization in Nanoparticle Dimers , 2004 .

[50]  P. Nordlander,et al.  A Hybridization Model for the Plasmon Response of Complex Nanostructures , 2003, Science.

[51]  David G. Lidzey,et al.  Cavity polaritons in microcavities containing disordered organic semiconductors , 2003 .

[52]  L. M. Brown,et al.  DIRECT AND INDIRECT TRANSITIONS IN THE REGION OF THE BAND GAP USING ELECTRON-ENERGY-LOSS SPECTROSCOPY , 1998 .

[53]  Zikang Tang,et al.  Room-temperature ultraviolet laser emission from self-assembled ZnO microcrystallite thin films , 1998 .

[54]  Richard H. Bube,et al.  Optical and electrical properties of ZnO films prepared by spray pyrolysis for solar cell applications , 1979 .

[55]  Jaebeom Lee,et al.  Exciton-plasmon interactions in molecular spring assemblies of nanowires and wavelength-based protein detection. , 2007, Nature materials.