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Gao L, Prokhorenko S, Nahas Y, Bellaiche L. Dynamical Control of Topology in Polar Skyrmions via Twisted Light. PHYSICAL REVIEW LETTERS 2024; 132:026902. [PMID: 38277608 DOI: 10.1103/physrevlett.132.026902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 09/23/2023] [Accepted: 11/08/2023] [Indexed: 01/28/2024]
Abstract
Twisted light carries a nonzero orbital angular momentum, that can be transferred from light to electrons and particles ranging from nanometers to micrometers. Up to now, the interplay between twisted light with dipolar systems has scarcely been explored, though the latter bear abundant forms of topologies such as skyrmions and embrace strong light-matter coupling. Here, using first-principles-based simulations, we show that twisted light can excite and drive dynamical polar skyrmions and transfer its nonzero winding number to ferroelectric ultrathin films. The skyrmion is successively created and annihilated alternately at the two interfaces, and experiences a periodic transition from a markedly "Bloch" to "Néel" character, accompanied with the emergence of a "Bloch point" topological defect with vanishing polarization. The dynamical evolution of skyrmions is connected to a constant jump of topological number between "0" and "1" over time. These intriguing phenomena are found to have an electrostatic origin. Our study thus demonstrates that, and explains why this unique light-matter interaction can be very powerful in creating and manipulating topological solitons in functional materials.
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Affiliation(s)
- Lingyuan Gao
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Sergei Prokhorenko
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Yousra Nahas
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Laurent Bellaiche
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
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Gao L, Prokhorenko S, Nahas Y, Bellaiche L. Dynamical Multiferroicity and Magnetic Topological Structures Induced by the Orbital Angular Momentum of Light in a Nonmagnetic Material. PHYSICAL REVIEW LETTERS 2023; 131:196801. [PMID: 38000422 DOI: 10.1103/physrevlett.131.196801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 09/19/2023] [Indexed: 11/26/2023]
Abstract
Recent studies have revealed that chiral phonons resonantly excited by ultrafast laser pulses carry magnetic moments and can enhance the magnetization of materials. In this work, using first-principles-based simulations, we present a real-space scenario where circular motions of electric dipoles in ultrathin two-dimensional ferroelectric and nonmagnetic films are driven by orbital angular momentum of light via strong coupling between electric dipoles and optical field. Rotations of these dipoles follow the evolving pattern of the optical field and create strong on-site orbital magnetic moments of ions. By characterizing topology of orbital magnetic moments in each 2D layer, we identify the vortex type of topological texture-magnetic merons with a one-half topological charge and robust stability. Our study thus provides alternative approaches for generating magnetic fields and topological textures from light-matter interaction and dynamical multiferroicity in nonmagnetic materials.
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Affiliation(s)
- Lingyuan Gao
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Sergei Prokhorenko
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Yousra Nahas
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Laurent Bellaiche
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, USA
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3
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Liu W, Min C, Zhang Y. Selective plasmonic trapping of nano-particles by Archimedes metalens. OPTICS EXPRESS 2023; 31:35354-35362. [PMID: 37859269 DOI: 10.1364/oe.497015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 09/18/2023] [Indexed: 10/21/2023]
Abstract
Optical tweezer is a non-invasive method for optical force tool applied in various fields like biology, physics, and lab on chip manipulation. The Archimedean helix shape is ideal for creating chiral nanostructures, and being able to generate plasmonic focused hotspot field for optical trapping. Here we design a metal disk with the Archimedean shape to own the ability of selective trapping nanoparticles based on the spin-orbit interactions with circularly polarized light. The plasmonic near field on the metalens can be designed by adjusting the geometric parameter flexibly. We numerically analyze the optimal size and screw pitch of the metal disk to realize the switch modulation of hotspot generation, and then demonstrate the novel switchable optical trapping ability in the view of optical force and potential well analysis under the circularly polarized light excitation by a 532 nm laser. The work shows significant potential for on-chip optical trapping in various fields.
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Taylor EJ, Iyer V, Dhami BS, Klein C, Lawrie BJ, Appavoo K. Hyperspectral mapping of nanoscale photophysics and degradation processes in hybrid perovskite at the single grain level. NANOSCALE ADVANCES 2023; 5:4687-4695. [PMID: 37705772 PMCID: PMC10496886 DOI: 10.1039/d3na00529a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 08/14/2023] [Indexed: 09/15/2023]
Abstract
With solar cells reaching 26.1% certified efficiency, hybrid perovskites are now the most efficient thin film photovoltaic material. Though substantial effort has focussed on synthesis approaches and device architectures to further improve perovskite-based solar cells, more work is needed to correlate physical properties of the underlying film structure with device performance. Here, using cathodoluminescence microscopy coupled with unsupervised machine learning, we quantify how nanoscale heterogeneity globally builds up within a large morphological grain of hybrid perovskite when exposed to extrinsic stimuli such as charge accumulation from electron beams or milder environmental factors like humidity. The converged electron-beam excitation allows us to map PbI2 and the emergence of other intermediate phases with high spatial and energy resolution. In contrast with recent reports of hybrid perovskite cathodoluminescence, we observe no significant change in the PbI2 signatures, even after high-energy electron beam excitation. In fact, we can exploit the stable PbI2 signatures to quantitatively map how hybrid perovskites degrade. Moreover, we show how our methodology allows disentangling of the photophysics associated with photon recycling and band-edge emission with sub-micron resolution using a fundamental understanding of electron interactions in hybrid perovskites.
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Affiliation(s)
- Ethan J Taylor
- Department of Physics, University of Alabama at Birmingham 1300 University Blvd., Birmingham AL 35294 USA
| | - Vasudevan Iyer
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Bibek S Dhami
- Department of Physics, University of Alabama at Birmingham 1300 University Blvd., Birmingham AL 35294 USA
| | - Clay Klein
- Clarion University 840 Wood St, Clarion PA 16214 USA
| | - Benjamin J Lawrie
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory Oak Ridge TN 37831 USA
- Materials Science and Technology Division, Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Kannatassen Appavoo
- Department of Physics, University of Alabama at Birmingham 1300 University Blvd., Birmingham AL 35294 USA
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5
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Dhami BS, Iyer V, Pant A, Tripathi RPN, Taylor EJ, Lawrie BJ, Appavoo K. Angle-resolved polarimetry of hybrid perovskite emission for photonic technologies. NANOSCALE 2022; 14:17519-17527. [PMID: 36409224 DOI: 10.1039/d2nr03261a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Coupling between light and matter strongly depends on the polarization of the electromagnetic field and the nature of excitations in a material. As hybrid perovskites emerge as a promising class of materials for light-based technologies such as LEDs, LASERs, and photodetectors, it is critical to understand how their microstructure changes the intrinsic properties of the photon emission process. While the majority of optical studies have focused on the spectral content, quantum efficiency and lifetimes of emission in various hybrid perovskite thin films and nanostructures, few studies have investigated other properties of the emitted photons such as polarization and emission angle. Here, we use angle-resolved cathodoluminescence microscopy to access the full polarization state of photons emitted from large-grain hybrid perovskite films with spatial resolution well below the optical diffraction limit. Mapping these Stokes parameters as a function of the angle at which the photons are emitted from the thin film surface, we reveal the effect of a grain boundary on the degree of polarization and angle at which the photons are emitted. Such studies of angle- and polarization-resolved emission at the single grain level are necessary for future development of perovskite-based flat optics, where effects of grain boundaries and interfaces need to be mitigated.
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Affiliation(s)
- Bibek S Dhami
- Department of Physics, University of Alabama at Birmingham, AL 35294, USA.
| | - Vasudevan Iyer
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge TN, 37831, USA
| | - Aniket Pant
- Department of Physics, University of Alabama at Birmingham, AL 35294, USA.
| | - Ravi P N Tripathi
- Department of Physics, University of Alabama at Birmingham, AL 35294, USA.
| | - Ethan J Taylor
- Department of Physics, University of Alabama at Birmingham, AL 35294, USA.
| | - Benjamin J Lawrie
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge TN, 37831, USA
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge TN, 37831, USA
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Zhang S, Huo P, Zhu W, Zhang C, Chen P, Liu M, Chen L, Lezec HJ, Agrawal A, Lu Y, Xu T. Broadband Detection of Multiple Spin and Orbital Angular Momenta via Dielectric Metasurface. LASER & PHOTONICS REVIEWS 2020; 14:2000062. [PMID: 33569085 PMCID: PMC7871458 DOI: 10.1002/lpor.202000062] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Affiliation(s)
- Si Zhang
- National Laboratory of Solid‐State Microstructures College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China
- Key Laboratory of Intelligent Optical Sensing and Manipulation Ministry of Education Nanjing University Nanjing 210093 China
| | - Pengcheng Huo
- National Laboratory of Solid‐State Microstructures College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China
- Key Laboratory of Intelligent Optical Sensing and Manipulation Ministry of Education Nanjing University Nanjing 210093 China
| | - Wenqi Zhu
- Physical Measurement Laboratory National Institute of Standards and Technology Gaithersburg Maryland 20899 USA
- Maryland NanoCenter University of Maryland College Park Maryland 20742 USA
| | - Cheng Zhang
- School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan 430074 China
- Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 China
| | - Peng Chen
- National Laboratory of Solid‐State Microstructures College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China
- Key Laboratory of Intelligent Optical Sensing and Manipulation Ministry of Education Nanjing University Nanjing 210093 China
| | - Mingze Liu
- National Laboratory of Solid‐State Microstructures College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China
- Key Laboratory of Intelligent Optical Sensing and Manipulation Ministry of Education Nanjing University Nanjing 210093 China
| | - Lu Chen
- Physical Measurement Laboratory National Institute of Standards and Technology Gaithersburg Maryland 20899 USA
- Maryland NanoCenter University of Maryland College Park Maryland 20742 USA
| | - Henri J. Lezec
- Physical Measurement Laboratory National Institute of Standards and Technology Gaithersburg Maryland 20899 USA
| | - Amit Agrawal
- Physical Measurement Laboratory National Institute of Standards and Technology Gaithersburg Maryland 20899 USA
- Maryland NanoCenter University of Maryland College Park Maryland 20742 USA
| | - Yanqing Lu
- National Laboratory of Solid‐State Microstructures College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China
- Key Laboratory of Intelligent Optical Sensing and Manipulation Ministry of Education Nanjing University Nanjing 210093 China
| | - Ting Xu
- National Laboratory of Solid‐State Microstructures College of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China
- Key Laboratory of Intelligent Optical Sensing and Manipulation Ministry of Education Nanjing University Nanjing 210093 China
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van Nielen N, Hentschel M, Schilder N, Giessen H, Polman A, Talebi N. Electrons Generate Self-Complementary Broadband Vortex Light Beams Using Chiral Photon Sieves. NANO LETTERS 2020; 20:5975-5981. [PMID: 32643947 DOI: 10.1021/acs.nanolett.0c01964] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Planar electron-driven photon sources have been recently proposed as miniaturized light sources, with prospects for ultrafast conjugate electron-photon microscopy and spectral interferometry. Such sources usually follow the symmetry of the electron-induced polarization: transition-radiation-based sources, for example, only generate p-polarized light. Here we demonstrate that the polarization, the bandwidth, and the directionality of photons can be tailored by utilizing photon-sieve-based structures. We design, fabricate, and characterize self-complementary chiral structures made of holes in an Au film and generate light vortex beams with specified angular momentum orders. The incoming electron interacting with the structure generates chiral surface plasmon polaritons on the structured Au surface that scatter into the far field. The outcoupled radiation interferes with transition radiation creating TE- and TM-polarized Laguerre-Gauss light beams with a chiral intensity distribution. The generated vortex light and its unique spatiotemporal features can form the basis for the generation of structured-light electron-driven photon sources.
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Affiliation(s)
- Nika van Nielen
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Mario Hentschel
- 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Nick Schilder
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Harald Giessen
- 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Albert Polman
- Center for Nanophotonics, AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
| | - Nahid Talebi
- Institute of Experimental and Applied Physics, Christian Albrechts University, Leibnizstrasse 19, 24118 Kiel, Germany
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Litvin IA, Mueller NS, Reich S. Selective excitation of localized surface plasmons by structured light. OPTICS EXPRESS 2020; 28:24262-24274. [PMID: 32752408 DOI: 10.1364/oe.399225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
We investigated the selective excitation of localized surface plasmons by structured light. We derive selection rules using group theory and propose a fitting integral to quantify the contribution of the eigenmodes to the absorption spectra. Based on the result we investigate three nano oligomers of different symmetry (trimer, quadrumer, and hexamer) in detail using finite-difference time-domain simulations. We show that by controlling the incident light polarization and phase pattern we are able to control the absorption and scattering spectra. Additionally, we demonstrate that the fitting between the incident light and the oligomer modes may favor a number of modes to oscillate. Dark modes produce strong changes in the absorption spectrum and bright modes in the scattering spectrum. The experimental precision (axial shift error) may be on the same order as the oligomer diameter making the orbital angular momentum selection rules robust enough for experimental observation.
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Guo WP, Liang WY, Cheng CW, Wu WL, Wang YT, Sun Q, Zu S, Misawa H, Cheng PJ, Chang SW, Ahn H, Lin MT, Gwo S. Chiral Second-Harmonic Generation from Monolayer WS 2/Aluminum Plasmonic Vortex Metalens. NANO LETTERS 2020; 20:2857-2864. [PMID: 32163291 DOI: 10.1021/acs.nanolett.0c00645] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Two-dimensional spiral plasmonic structures have emerged as a versatile approach to generate near-field vortex fields with tunable topological charges. We demonstrate here a far-field approach to observe the chiral second-harmonic generation (SHG) at designated visible wavelengths from a single plasmonic vortex metalens. This metalens comprises an Archimedean spiral slit fabricated on atomically flat aluminum epitaxial film, which allows for precise tuning of plasmonic resonances and subsequent transfer of two-dimensional materials on top of the spiral slit. The nonlinear optical measurements show a giant SHG circular dichroism. Furthermore, we have achieved an enhanced chiral SHG conversion efficiency (about an order of magnitude greater than the bare aluminum lens) from monolayer tungsten disulfide (WS2)/aluminum metalens, which is designed at the C-exciton resonance of WS2. Since the C-exciton is not a valley exciton, the enhanced chiral SHG in this hybrid system originates from the plasmonic vortex field-enhanced SHG under the optical spin-orbit interaction.
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Affiliation(s)
- Wan-Ping Guo
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
| | - Wei-Yun Liang
- Department of Photonics, College of Electrical and Computer Engineering, National Chiao-Tung University, Hsinchu 30010, Taiwan
| | - Chang-Wei Cheng
- Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Wei-Lin Wu
- Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Yen-Ting Wang
- Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan
| | - Quan Sun
- Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Shuai Zu
- Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Hiroaki Misawa
- Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan
- Center for Emergent Functional Matter Science, National Chiao-Tung University, Hsinchu 30010, Taiwan
| | - Pi-Ju Cheng
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Shu-Wei Chang
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Hyeyoung Ahn
- Department of Photonics, College of Electrical and Computer Engineering, National Chiao-Tung University, Hsinchu 30010, Taiwan
| | - Minn-Tsong Lin
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Shangjr Gwo
- Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
- Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan
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Liu K, Maccaferri N, Shen Y, Li X, Zaccaria RP, Zhang X, Gorodetski Y, Garoli D. Particle trapping and beaming using a 3D nanotip excited with a plasmonic vortex. OPTICS LETTERS 2020; 45:823-826. [PMID: 32058479 DOI: 10.1364/ol.384899] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 01/02/2020] [Indexed: 06/10/2023]
Abstract
Recent advances in nanotechnology have prompted the need for tools to accurately and noninvasively manipulate individual nano-objects. Among the possible strategies, optical forces have been widely used to enable nano-optical tweezers capable of trapping or moving a specimen with unprecedented accuracy. Here, we propose an architecture consisting of a nanotip excited with a plasmonic vortex enabling effective dynamic control of nanoparticles in three dimensions. The structure illuminated by a beam with angular momentum can generate an optical field that can be used to manipulate single dielectric nanoparticles. We demonstrate that it is possible to stably trap or push the particle from specific points, thus enabling a new, to the best of our knowledge, platform for nanoparticle manipulation.
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Zachman MJ, Hachtel JA, Idrobo JC, Chi M. Emerging Electron Microscopy Techniques for Probing Functional Interfaces in Energy Materials. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201902993] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Michael J. Zachman
- Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Jordan A. Hachtel
- Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Juan Carlos Idrobo
- Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 37831 USA
| | - Miaofang Chi
- Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 37831 USA
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Zachman MJ, Hachtel JA, Idrobo JC, Chi M. Emerging Electron Microscopy Techniques for Probing Functional Interfaces in Energy Materials. Angew Chem Int Ed Engl 2019; 59:1384-1396. [PMID: 31081976 DOI: 10.1002/anie.201902993] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 05/01/2019] [Indexed: 11/10/2022]
Abstract
Interfaces play a fundamental role in many areas of chemistry. However, their localized nature requires characterization techniques with high spatial resolution in order to fully understand their structure and properties. State-of-the-art atomic resolution or in situ scanning transmission electron microscopy and electron energy-loss spectroscopy are indispensable tools for characterizing the local structure and chemistry of materials with single-atom resolution, but they are not able to measure many properties that dictate function, such as vibrational modes or charge transfer, and are limited to room-temperature samples containing no liquids. Here, we outline emerging electron microscopy techniques that are allowing these limitations to be overcome and highlight several recent studies that were enabled by these techniques. We then provide a vision for how these techniques can be paired with each other and with in situ methods to deliver new insights into the static and dynamic behavior of functional interfaces.
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Affiliation(s)
- Michael J Zachman
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jordan A Hachtel
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Juan Carlos Idrobo
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Miaofang Chi
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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Orientation of Chiral Schiff Base Metal Complexes Involving Azo-Groups for Induced CD on Gold Nanoparticles by Polarized UV Light Irradiation. Symmetry (Basel) 2019. [DOI: 10.3390/sym11091094] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In this study, we report the synthesis, characterization, and chiroptical properties of azo-group-containing chiral salen type Schiff base Ni(II), Cu(II), and Zn(II) complexes absorbed on gold nanoparticles (AuNPs) of 10 nm diameters. Induced circular dichroism (CD) around the plasmon region from the chiral species weakly adsorbed on the surface of AuNP were observed when there were appropriate dipole–dipole interactions at the initial states. Spectral changes were also observed by not only cis-trans photoisomerization of azo-groups but also changes of orientation due to Weigert effect of azo-dyes after linearly polarized UV light irradiation. Spatial features were discussed based on dipole-dipole interactions mainly within an exciton framework.
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