Locally enhanced cathodoluminescence of electrochemically fabricated gold nanostructures

Abstract Three dimensional structures of Au with submicron sizes and high aspect ratios were fabricated by electrochemical micromachining with short voltage pulses. Due to the use of LiCl/dimethyl sulfoxide electrolytes, submicrometer machining-precision was achieved with voltage pulses of moderate duration of the order of 10 ns. Careful adjustment of the machining parameters like rest potentials of tool and workpiece and pulse amplitude allowed for the routine fabrication of Au microstructures. The optical properties of such structures were investigated by measuring their cathodoluminescence upon electron irradiation in a scanning electron microscope. Excitation of localized plasmons in small structures led to the enhancement of the light emission by a factor of up to 2.5, if compared to the bare Au surface.

[1]  N. Yamamoto,et al.  Cherenkov and transition radiation from thin plate crystals detected in the transmission electron microscope , 1996, Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

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

[3]  U. Welp,et al.  Surface plasmons at single nanoholes in Au films , 2004 .

[4]  E. Ozbay.  Plasmonics: Merging Photonics and Electronics at Nanoscale Dimensions , 2006, Science.

[5]  Jeffrey N. Anker,et al.  Biosensing with plasmonic nanosensors. , 2008, Nature materials.

[6]  Harry A. Atwater,et al.  Local density of states, spectrum, and far-field interference of surface plasmon polaritons probed by cathodoluminescence , 2009 .

[7]  Albert Polman,et al.  Plasmonic modes of annular nanoresonators imaged by spectrally resolved cathodoluminescence. , 2007, Nano letters.

[8]  R. Zenobi,et al.  Nanoscale chemical analysis by tip-enhanced Raman spectroscopy , 2000 .

[9]  A. Polman,et al.  Modal decomposition of surface--plasmon whispering gallery resonators. , 2009, Nano letters.

[10]  H. Lezec,et al.  Surface plasmon polariton modes in a single-crystal Au nanoresonator fabricated using focused-ion-beam milling , 2008, 0801.1267.

[11]  Kurt Busch,et al.  Three‐Dimensional Nanostructures for Photonics , 2010 .

[12]  Eric Bourillot,et al.  Squeezing the Optical Near-Field Zone by Plasmon Coupling of Metallic Nanoparticles , 1999 .

[13]  A. Agarwal,et al.  Electron-beam mapping of plasmon resonances in electromagnetically interacting gold nanorods , 2009 .

[14]  Steven R. Emory,et al.  Probing Single Molecules and Single Nanoparticles by Surface-Enhanced Raman Scattering , 1997, Science.

[15]  H. Okamoto,et al.  Near-field optical imaging of enhanced electric fields and plasmon waves in metal nanostructures , 2009 .

[16]  Xinzhou Ma,et al.  Electrochemical machining of gold microstructures in LiCl/dimethyl sulfoxide. , 2010, Chemphyschem : a European journal of chemical physics and physical chemistry.

[17]  B. Pettinger,et al.  Tip-enhanced Raman spectroscopy and microscopy on single dye molecules with 15 nm resolution. , 2008, Physical review letters.

[18]  W. Barnes,et al.  Surface plasmon subwavelength optics , 2003, Nature.

[19]  William L. Barnes,et al.  Sensitivity of Localized Surface Plasmon Resonances to Bulk and Local Changes in the Optical Environment , 2009 .

[20]  R. Dasari,et al.  Single Molecule Detection Using Surface-Enhanced Raman Scattering (SERS) , 1997 .

[21]  A. Polman,et al.  Direct observation of plasmonic modes in au nanowires using high-resolution cathodoluminescence spectroscopy. , 2007, Nano letters.

[22]  K. Araya,et al.  Light emission from surfaces, thin films and particles induced by high‐energy electron beam , 2001 .

[23]  Ewold Verhagen,et al.  Direct imaging of propagation and damping of near-resonance surface plasmon polaritons using cathodoluminescence spectroscopy , 2006 .

[24]  R. Schuster.  Electrochemical microstructuring with short voltage pulses. , 2007, Chemphyschem : a European journal of chemical physics and physical chemistry.

[25]  Heinz Raether,et al.  BOOKS: Pattern Recognition in Practice: Proceedings, International Workshop, Amsterdam, 21-23 May 1980; Optical Fiber Systems and Their Components: An Introduction; Excitation of Plasmons and Interband Transitions by Electrons. , 1980, Applied optics.

[26]  Gerhard Ertl,et al.  Nanoscale probing of adsorbed species by tip-enhanced Raman spectroscopy. , 2004, Physical review letters.

[27]  H. Lezec,et al.  Loss mechanisms of surface plasmon polaritons on gold probed by cathodoluminescence imaging spectroscopy , 2008 .

[28]  F. D. Abajo,et al.  Optical excitations in electron microscopy , 2009, 0903.1669.

[29]  N I Zheludev,et al.  Generation of traveling surface plasmon waves by free-electron impact. , 2006, Nano letters.

[30]  Thomas W. Ebbesen,et al.  Optical transmission properties of a single subwavelength aperture in a real metal , 2004 .

[31]  Masashi Watanabe,et al.  Mapping surface plasmons at the nanometre scale with an electron beam , 2007 .

[32]  T. Ebbesen,et al.  Channel plasmon subwavelength waveguide components including interferometers and ring resonators , 2006, Nature.