1
|
Dang Z, Chen Y, Fang Z. Cathodoluminescence Nanoscopy: State of the Art and Beyond. ACS NANO 2023; 17:24431-24448. [PMID: 38054434 DOI: 10.1021/acsnano.3c07593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Cathodoluminescence (CL) nanoscopy is proven to be a powerful tool to explore nanoscale optical properties, whereby free electron beams achieve a spatial resolution far beyond the diffraction limit of light. With developed methods for the control of electron beams and the collection of light, the dimension of information that CL can access has been expanded to include polarization, momentum, and time, holding promise to provide invaluable insights into the study of materials and optical near-field dynamics. With a focus on the burgeoning field of CL nanoscopy, this perspective outlines the recent advancements and applications of this technique, as illustrated by the salient experimental works. In addition, as an outlook for future research, several appealing directions that may bring about developments and discoveries are highlighted.
Collapse
Affiliation(s)
- Zhibo Dang
- School of Physics, State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, People's Republic of China
| | - Yuxiang Chen
- School of Physics, State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, People's Republic of China
| | - Zheyu Fang
- School of Physics, State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, Collaborative Innovation Center of Quantum Matter, and Nano-optoelectronics Frontier Center of Ministry of Education, Peking University, Beijing 100871, People's Republic of China
| |
Collapse
|
2
|
Yamada R, Kimura R, Kuwahara S. Depletion force optimization for high-purity gold nanotriangles prepared using different growth methods. RSC Adv 2023; 13:32143-32149. [PMID: 37928845 PMCID: PMC10620599 DOI: 10.1039/d3ra05955c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 10/26/2023] [Indexed: 11/07/2023] Open
Abstract
A homogeneous structural distribution in metal nanoparticle is commonly required for their application, and despite high-yield growth techniques, unavoidable structural heterogeneity remains a concern in metal nanoparticle synthesis. Gold nanotriangles (AuNTs) were synthesized using seed-mediated and seedless growth methods. Recent advancements in high-yield synthesis processes have enabled easy handling of AuNTs, which exhibit unique localized surface plasmon resonance characteristics due to their anisotropic triangular form. The flocculation and subsequent precipitation technique was used to purify AuNTs of different sizes synthesized using seed-mediated and seedless growth methods. The optimal conditions for obtaining high-purity AuNTs were explored by introducing a high concentration of cetyltrimethylammonium chloride. Additionally, the depletion force necessary for achieving high-purity AuNTs was calculated to reveal variations in the required depletion forces for AuNTs synthesized using different growth techniques. The alternations in the size distribution of AuNTs during the flocculation step were tracked using dynamic light scattering, and the surface charge of AuNTs synthesized through different growth methods was evaluated by ζ-potential. The high purity of the AuNTs produced using the seedless growth method required a larger depletion force than the seed-mediated grown AuNTs. The difference in the required depletion forces results from the difference in the electrostatic forces caused by the different growth methods.
Collapse
Affiliation(s)
- Ryuichi Yamada
- Department of Chemistry, Faculty of Science, Toho University Funabashi Chiba 274-8510 Japan
| | - Ryusei Kimura
- Department of Chemistry, Faculty of Science, Toho University Funabashi Chiba 274-8510 Japan
| | - Shota Kuwahara
- Department of Chemistry, Faculty of Science, Toho University Funabashi Chiba 274-8510 Japan
| |
Collapse
|
3
|
Zámbó D, Kovács D, Südi G, Zolnai Z, Deák A. Composite ligand shells on gold nanoprisms - an ensemble and single particle study. RSC Adv 2023; 13:30696-30703. [PMID: 37869380 PMCID: PMC10585614 DOI: 10.1039/d3ra05548e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 10/11/2023] [Indexed: 10/24/2023] Open
Abstract
The attachment of thiolated molecules onto gold surfaces is one of the most extensively used and robust ligand exchange approaches to exploit the nanooptical features of nanoscale and nanostructured plasmonic materials. In this work, the impact of thiol adsorption on the optical properties of wet-chemically synthesized gold nanoprisms is studied both at the ensemble and single particle level to investigate the build-up of more complex ligand layers. Two prototypical ligands with different lengths have been investigated ((16-mercaptohexadecyl)trimethylammonium bromide - MTAB and thiolated polyethylene glycol - mPEG-SH). From ensemble experiments it is found that composite ligand layers are obtained by the sequential addition of the two thiols, and an island-like surface accumulation of the molecules can be anticipated. The single particle experiment derived chemical interface damping and resonance energy changes further support this and show additionally that when the two thiols are used simultaneously, a higher density, intermixed layer is formed. Hence, when working with more than a single type of ligand during surface modification, sequential adsorption is preferred for the combination of accessible essential surface functionalities, whereas for high overall loading the simultaneous use of the different ligand types is favourable.
Collapse
Affiliation(s)
- Dániel Zámbó
- Centre for Energy Research Konkoly-ThegeM. Str. 29-33 Budapest 1121 Hungary
| | - Dávid Kovács
- Centre for Energy Research Konkoly-ThegeM. Str. 29-33 Budapest 1121 Hungary
- Budapest University of Technology and Economics, Department of Physical Chemistry and Materials Science Budafoki Str. 6-8 Budapest 1117 Hungary
| | - Gergely Südi
- Centre for Energy Research Konkoly-ThegeM. Str. 29-33 Budapest 1121 Hungary
- Budapest University of Technology and Economics, Department of Physical Chemistry and Materials Science Budafoki Str. 6-8 Budapest 1117 Hungary
| | - Zsolt Zolnai
- Centre for Energy Research Konkoly-ThegeM. Str. 29-33 Budapest 1121 Hungary
| | - András Deák
- Centre for Energy Research Konkoly-ThegeM. Str. 29-33 Budapest 1121 Hungary
| |
Collapse
|
4
|
Chikkaraddy R, Huang J, Kos D, Elliott E, Kamp M, Guo C, Baumberg JJ, de Nijs B. Boosting Optical Nanocavity Coupling by Retardation Matching to Dark Modes. ACS PHOTONICS 2023; 10:493-499. [PMID: 36820326 PMCID: PMC9936626 DOI: 10.1021/acsphotonics.2c01603] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Indexed: 06/18/2023]
Abstract
Plasmonic nanoantennas can focus light at nanometer length scales providing intense field enhancements. For the tightest optical confinements (0.5-5 nm) achieved in plasmonic gaps, the gap spacing, refractive index, and facet width play a dominant role in determining the optical properties making tuning through antenna shape challenging. We show here that controlling the surrounding refractive index instead allows both efficient frequency tuning and enhanced in-/output coupling through retardation matching as this allows dark modes to become optically active, improving widespread functionalities.
Collapse
Affiliation(s)
- Rohit Chikkaraddy
- NanoPhotonics
Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thompson Avenue, CambridgeCB3 0HE, U.K.
| | - Junyang Huang
- NanoPhotonics
Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thompson Avenue, CambridgeCB3 0HE, U.K.
| | - Dean Kos
- NanoPhotonics
Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thompson Avenue, CambridgeCB3 0HE, U.K.
| | - Eoin Elliott
- NanoPhotonics
Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thompson Avenue, CambridgeCB3 0HE, U.K.
| | - Marlous Kamp
- NanoPhotonics
Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thompson Avenue, CambridgeCB3 0HE, U.K.
| | - Chenyang Guo
- NanoPhotonics
Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thompson Avenue, CambridgeCB3 0HE, U.K.
| | - Jeremy J. Baumberg
- NanoPhotonics
Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thompson Avenue, CambridgeCB3 0HE, U.K.
| | - Bart de Nijs
- NanoPhotonics
Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, JJ Thompson Avenue, CambridgeCB3 0HE, U.K.
| |
Collapse
|
5
|
Farheen H, Yan LY, Quiring V, Eigner C, Zentgraf T, Linden S, Förstner J, Myroshnychenko V. Broadband optical Ta 2O 5 antennas for directional emission of light. OPTICS EXPRESS 2022; 30:19288-19299. [PMID: 36221710 DOI: 10.1364/oe.455815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 04/09/2022] [Indexed: 06/16/2023]
Abstract
Highly directive antennas with the ability of shaping radiation patterns in desired directions are essential for efficient on-chip optical communication with reduced cross talk. In this paper, we design and optimize three distinct broadband traveling-wave tantalum pentoxide antennas exhibiting highly directional characteristics. Our antennas contain a director and reflector deposited on a glass substrate, which are excited by a dipole emitter placed in the feed gap between the two elements. Full-wave simulations in conjunction with global optimization provide structures with an enhanced linear directivity as high as 119 radiating in the substrate. The high directivity is a result of the interplay between two dominant TE modes and the leaky modes present in the antenna director. Furthermore, these low-loss dielectric antennas exhibit a near-unity radiation efficiency at the operational wavelength of 780 nm and maintain a broad bandwidth. Our numerical results are in good agreement with experimental measurements from the optimized antennas fabricated using a two-step electron-beam lithography, revealing the highly directive nature of our structures. We envision that our antenna designs can be conveniently adapted to other dielectric materials and prove instrumental for inter-chip optical communications and other on-chip applications.
Collapse
|
6
|
Imaeda K, Hasegawa S, Imura K. Observation of the plasmon mode transition from triangular to hexagonal nanoplates. J Chem Phys 2022; 156:044702. [DOI: 10.1063/5.0078371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Keisuke Imaeda
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Seiju Hasegawa
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555, Japan
| | - Kohei Imura
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555, Japan
| |
Collapse
|
7
|
Giovannini T, Bonatti L, Polini M, Cappelli C. Graphene Plasmonics: Fully Atomistic Approach for Realistic Structures. J Phys Chem Lett 2020; 11:7595-7602. [PMID: 32805117 PMCID: PMC7503861 DOI: 10.1021/acs.jpclett.0c02051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We demonstrate that the plasmonic properties of realistic graphene and graphene-based materials can effectively and accurately be modeled by a novel, fully atomistic, yet classical, approach, named ωFQ. Such a model is able to reproduce all plasmonic features of these materials and their dependence on shape, dimension, and fundamental physical parameters (Fermi energy, relaxation time, and two-dimensional electron density). Remarkably, ωFQ is able to accurately reproduce experimental data for realistic structures of hundreds of nanometers (∼370k atoms), which cannot be afforded by any ab initio method. Also, the atomistic nature of ωFQ permits the investigation of complex shapes, which can hardly be dealt with by exploiting widespread continuum approaches.
Collapse
Affiliation(s)
- Tommaso Giovannini
- Department
of Chemistry, Norwegian University of Science
and Technology, 7491 Trondheim, Norway
| | - Luca Bonatti
- Scuola
Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
| | - Marco Polini
- Dipartimento
di Fisica dell’Universitá di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy
- Istituto
Italiano di Tecnologia, Graphene Laboratories, Via Morego 30, 16163 Genova, Italy
| | - Chiara Cappelli
- Scuola
Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.
| |
Collapse
|
8
|
Askes SHC, Schilder NJ, Zoethout E, Polman A, Garnett EC. Tunable plasmonic HfN nanoparticles and arrays. NANOSCALE 2019; 11:20252-20260. [PMID: 31624815 DOI: 10.1039/c9nr07683b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We present the fabrication of tunable plasmonic hafnium nitride (HfN) nanoparticles. HfN is a metallic refractory material with the potential of supporting plasmon resonances in the visible range, similar to silver and gold, but with the additional benefits of high melting point, chemical stability, and mechanical hardness. However, the preparation of HfN nanoparticles and the experimental demonstration of their plasmonic potential are still in their infancy. Here, high quality HfN thin films were fabricated, for which ellipsometry shows their plasmonic potential. From these thin films, nanorods and nanotriangles were milled using a focused ion beam and the plasmon resonances were identified using cathodoluminescence mapping. As an alternative fabrication strategy, an optimized electron-beam lithography procedure was used to prepare arrays of HfN nanoparticles, which also exhibited clear surface plasmon resonances. These results pave the way to further explore HfN nanoparticles in plasmonically-powered applications where materials robustness is essential.
Collapse
Affiliation(s)
- Sven H C Askes
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
| | - Nick J Schilder
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
| | - Erwin Zoethout
- Dutch Institute for Fundamental Energy Research (DIFFER), De Zaale 20, 5612 AJ Eindhoven, The Netherlands
| | - Albert Polman
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
| | - Erik C Garnett
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands.
| |
Collapse
|
9
|
Polman A, Kociak M, García de Abajo FJ. Electron-beam spectroscopy for nanophotonics. NATURE MATERIALS 2019; 18:1158-1171. [PMID: 31308514 DOI: 10.1038/s41563-019-0409-1] [Citation(s) in RCA: 98] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 05/04/2019] [Accepted: 05/14/2019] [Indexed: 05/22/2023]
Abstract
Progress in electron-beam spectroscopies has recently enabled the study of optical excitations with combined space, energy and time resolution in the nanometre, millielectronvolt and femtosecond domain, thus providing unique access into nanophotonic structures and their detailed optical responses. These techniques rely on ~1-300 keV electron beams focused at the sample down to sub-nanometre spots, temporally compressed in wavepackets a few femtoseconds long, and in some cases controlled by ultrafast light pulses. The electrons undergo energy losses and gains (also giving rise to cathodoluminescence light emission), which are recorded to reveal the optical landscape along the beam path. This Review portraits these advances, with a focus on coherent excitations, emphasizing the increasing level of control over the electron wavefunctions and ensuing applications in the study and technological use of optically resonant modes and polaritons in nanoparticles, 2D materials and engineered nanostructures.
Collapse
Affiliation(s)
- Albert Polman
- Center for Nanophotonics, AMOLF, Amsterdam, the Netherlands.
| | - Mathieu Kociak
- Laboratoire de Physique des Solides, Université de Paris-Sud, Orsay, France
| | - F Javier García de Abajo
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
- ICREA-Institució Catalana de Reserca I Estudis Avançats, Barcelona, Spain
| |
Collapse
|
10
|
Fouchier M, Rochat N, Pargon E, Landesman JP. Polarized cathodoluminescence for strain measurement. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:043701. [PMID: 31043017 DOI: 10.1063/1.5078506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 03/15/2019] [Indexed: 06/09/2023]
Abstract
Strain can alter the properties of semiconductor materials. The selection of a strain measurement technique is a trade-off between sensitivity, resolution, and field of view, among other factors. We introduce a new technique based on the degree of polarization of cathodoluminescence (CL), which has excellent sensitivity (10-5), an intermediate resolution (about 100 nm), and an adjustable field of view. The strain information provided is complementary to that obtained by CL spectroscopy. Feasibility studies are presented. The experimental setup and the data treatment procedure are described in detail. Current limitations are highlighted. The technique is tested on the cross section of bulk indium phosphide samples strained by a patterned hard mask.
Collapse
Affiliation(s)
- M Fouchier
- Université Grenoble Alpes, CNRS, LTM, F-38000 Grenoble, France
| | - N Rochat
- Université Grenoble Alpes, CEA, LETI, F-38000 Grenoble, France
| | - E Pargon
- Université Grenoble Alpes, CNRS, LTM, F-38000 Grenoble, France
| | - J P Landesman
- Université de Rennes, CNRS, IPR (Institut de Physique de Rennes)-UMR 6251, F-35000 Rennes, France
| |
Collapse
|