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Avotina L, Bikse L, Dekhtyar Y, Goldmane AE, Kizane G, Muhin A, Romanova M, Smits K, Sorokins H, Vilken A, Zaslavskis A. Tungsten-SiO 2-Based Planar Field Emission Microtriodes with Different Electrode Topologies. MATERIALS (BASEL, SWITZERLAND) 2023; 16:5781. [PMID: 37687474 PMCID: PMC10488438 DOI: 10.3390/ma16175781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/14/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023]
Abstract
This study examines the electrical properties and layer quality of field emission microtriodes that have planar electrode geometry and are based on tungsten (W) and silicon dioxide (SiO2). Two types of microtriodes were analyzed: one with a multi-tip cathode fabricated using photolithography (PL) and the other with a single-tip cathode fabricated using a focused ion beam (FIB). Atomic force microscopy (AFM) analysis revealed surface roughness of the W layer in the order of several nanometers (Ra = 3.8 ± 0.5 nm). The work function values of the Si substrate, SiO2 layer, and W layer were estimated using low-energy ultraviolet photoelectron emission (PE) spectroscopy and were 4.71 eV, 4.85 eV, and 4.67 eV, respectively. The homogeneity of the W layer and the absence of oxygen and silicon impurities were confirmed via X-ray photoelectron spectroscopy (XPS). The PL microtriode and the FIB microtriode exhibited turn-on voltages of 110 V and 50 V, respectively, both demonstrating a field emission current of 0.4 nA. The FIB microtriode showed significantly improved field emission efficiency compared to the PL microtriode, attributed to a higher local electric field near the cathode.
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Affiliation(s)
- Liga Avotina
- Institute of Chemical Physics, University of Latvia, Jelgavas Street 1, LV-1004 Riga, Latvia; (L.A.); (A.E.G.); (G.K.)
| | - Liga Bikse
- Institute of Solid State Physics, University of Latvia, Kengaraga Street 8, LV-1063 Riga, Latvia; (L.B.); (K.S.)
| | - Yuri Dekhtyar
- Institute of Biomedical Engineering and Nanotechnologies, Riga Technical University, 6B Kipsalas Street, LV-1048 Riga, Latvia; (M.R.); (H.S.); (A.V.)
| | - Annija Elizabete Goldmane
- Institute of Chemical Physics, University of Latvia, Jelgavas Street 1, LV-1004 Riga, Latvia; (L.A.); (A.E.G.); (G.K.)
| | - Gunta Kizane
- Institute of Chemical Physics, University of Latvia, Jelgavas Street 1, LV-1004 Riga, Latvia; (L.A.); (A.E.G.); (G.K.)
| | - Aleksei Muhin
- Joint Stock Company “ALFA RPAR”, 140 Ropazu Street, LV-1006 Riga, Latvia
| | - Marina Romanova
- Institute of Biomedical Engineering and Nanotechnologies, Riga Technical University, 6B Kipsalas Street, LV-1048 Riga, Latvia; (M.R.); (H.S.); (A.V.)
| | - Krisjanis Smits
- Institute of Solid State Physics, University of Latvia, Kengaraga Street 8, LV-1063 Riga, Latvia; (L.B.); (K.S.)
| | - Hermanis Sorokins
- Institute of Biomedical Engineering and Nanotechnologies, Riga Technical University, 6B Kipsalas Street, LV-1048 Riga, Latvia; (M.R.); (H.S.); (A.V.)
| | - Aleksandr Vilken
- Institute of Biomedical Engineering and Nanotechnologies, Riga Technical University, 6B Kipsalas Street, LV-1048 Riga, Latvia; (M.R.); (H.S.); (A.V.)
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Chen Y, Tang S, Shen Y, Chen H, Deng S. A tunable photo-electric co-excited point electron source: low-intensity excitation emission and structure-modulated spectrum-selection. NANOSCALE 2023; 15:8643-8653. [PMID: 37128823 DOI: 10.1039/d3nr00652b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The development of a point electron source requires an efficient excitation mode with low energy consumption, flexible tunability, and high performance. In particular for traditional electron emission cathode materials, it is necessary to expand the function of this aspect to meet application demands in many emerging fields. In this study, we propose a photo-electric co-excited scheme to drive a tungsten (W) needle nano-cold-cathode. The developed W needle cathode has been demonstrated to show electron emission performance with a narrow energy spread of 0.76 eV and a high brightness of 4 × 109 A m-2 sr-1 V-1. This could be achieved through low-intensity co-excitation, including an electrostatic field below ∼0.5 V μm-1 and a laser intensity at ∼10 W cm-2 level. Based on this co-excitation, the electron emission further exhibited a tunable property relative to the intrinsic properties of the incident light, such as optical frequency and polarization, which is shown to be directly modulated by the structure of the W needle nano-cold-cathode. This work provides a choice to achieve tunable, miniaturized and integrated vacuum micro- and nano-electronic devices.
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Affiliation(s)
- Yinyao Chen
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China.
| | - Shuai Tang
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China.
| | - Yan Shen
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China.
| | - Huanjun Chen
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China.
| | - Shaozhi Deng
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China.
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3
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Plasmonic phenomena in molecular junctions: principles and applications. Nat Rev Chem 2022; 6:681-704. [PMID: 37117494 DOI: 10.1038/s41570-022-00423-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2022] [Indexed: 11/08/2022]
Abstract
Molecular junctions are building blocks for constructing future nanoelectronic devices that enable the investigation of a broad range of electronic transport properties within nanoscale regions. Crossing both the nanoscopic and mesoscopic length scales, plasmonics lies at the intersection of the macroscopic photonics and nanoelectronics, owing to their capability of confining light to dimensions far below the diffraction limit. Research activities on plasmonic phenomena in molecular electronics started around 2010, and feedback between plasmons and molecular junctions has increased over the past years. These efforts can provide new insights into the near-field interaction and the corresponding tunability in properties, as well as resultant plasmon-based molecular devices. This Review presents the latest advancements of plasmonic resonances in molecular junctions and details the progress in plasmon excitation and plasmon coupling. We also highlight emerging experimental approaches to unravel the mechanisms behind the various types of light-matter interactions at molecular length scales, where quantum effects come into play. Finally, we discuss the potential of these plasmonic-electronic hybrid systems across various future applications, including sensing, photocatalysis, molecular trapping and active control of molecular switches.
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Zhang L, Wang X, Chen H, Liu C, Deng S. A planar plasmonic nano-gap and its array for enhancing light-matter interactions at the nanoscale. NANOSCALE 2022; 14:12257-12264. [PMID: 35968906 DOI: 10.1039/d2nr01282k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Gap surface plasmon (GSP) modes, the localized electromagnetic modes existing between two metal structures separated by a nano-gap, are able to support subwavelength confinement and enhancement of a light field upon resonance excitation. Such features can greatly facilitate various light-matter interactions at the nanoscale. Here, we demonstrate a planar nano-gap architecture existing between a pair of tip-shaped gold pads. The nano-gap gives rise to plasmon resonances with strong light confinement close to the tip surfaces in the visible to near-infrared spectral region. Accordingly, we showed that the plasmonic gold nano-gap can exhibit strong intrinsic second-harmonic generation (SHG) and significantly enhance the Raman scattering signal from small molecules. Furthermore, by arranging the nano-gap into arrays, a stronger SHG signal can be obtained. In addition, the surface enhanced Raman scattering (SERS) activity is also improved by two orders of magnitude compared to that of a single nano-gap. Overall, the findings in our study have demonstrated the potential applications of a plasmonic nano-gap and its arrays for signal generation and sensitive chemical sensing at the nanoscale.
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Affiliation(s)
- Li Zhang
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China.
| | - Ximiao Wang
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China.
| | - Huanjun Chen
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China.
| | - Chuan Liu
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China.
| | - Shaozhi Deng
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China.
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Yakunin AN, Zarkov SV, Avetisyan YA, Akchurin GG, Aban’shin NP, Tuchin VV. Modeling of Laser-Induced Plasmon Effects in GNS-DLC-Based Material for Application in X-ray Source Array Sensors. SENSORS 2021; 21:s21041248. [PMID: 33578701 PMCID: PMC7916327 DOI: 10.3390/s21041248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 01/25/2021] [Accepted: 02/06/2021] [Indexed: 11/29/2022]
Abstract
An important direction in the development of X-ray computed tomography sensors in systems with increased scanning speed and spatial resolution is the creation of an array of miniature current sources. In this paper, we describe a new material based on gold nanostars (GNS) embedded in nanoscale diamond-like carbon (DLC) films (thickness of 20 nm) for constructing a pixel current source with photoinduced electron emission. The effect of localized surface plasmon resonance in GNS on optical properties in the wavelength range from UV to near IR, peculiarities of localization of field and thermal sources, generation of high-energy hot electrons, and mechanisms of their transportation in vacuum are investigated. The advantages of the proposed material and the prospects for using X-ray computed tomography in the matrix source are evaluated.
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Affiliation(s)
- Alexander N. Yakunin
- Laboratory of System Problems in Control and Automation in Mechanical Engineering, Institute of Precision Mechanics and Control, RAS, 410028 Saratov, Russia
- Correspondence: ; Tel.: +7-845-222-2376
| | - Sergey V. Zarkov
- Laboratory of Laser Diagnostics of Technical and Living Systems, Institute of Precision Mechanics and Control, RAS, 410028 Saratov, Russia; (S.V.Z.); (Y.A.A.); (G.G.A.); (V.V.T.)
| | - Yuri A. Avetisyan
- Laboratory of Laser Diagnostics of Technical and Living Systems, Institute of Precision Mechanics and Control, RAS, 410028 Saratov, Russia; (S.V.Z.); (Y.A.A.); (G.G.A.); (V.V.T.)
| | - Garif G. Akchurin
- Laboratory of Laser Diagnostics of Technical and Living Systems, Institute of Precision Mechanics and Control, RAS, 410028 Saratov, Russia; (S.V.Z.); (Y.A.A.); (G.G.A.); (V.V.T.)
- Department of Optics and Biophotonics, Saratov State University, 410012 Saratov, Russia
| | | | - Valery V. Tuchin
- Laboratory of Laser Diagnostics of Technical and Living Systems, Institute of Precision Mechanics and Control, RAS, 410028 Saratov, Russia; (S.V.Z.); (Y.A.A.); (G.G.A.); (V.V.T.)
- Department of Optics and Biophotonics, Saratov State University, 410012 Saratov, Russia
- Interdisciplinary Laboratory of Biophotonics, Tomsk State University, 634050 Tomsk, Russia
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6
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Sun S, Sun X, Bartles D, Wozniak E, Williams J, Zhang P, Ruan CY. Direct imaging of plasma waves using ultrafast electron microscopy. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:064301. [PMID: 33415182 PMCID: PMC7772000 DOI: 10.1063/4.0000044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 11/30/2020] [Indexed: 06/12/2023]
Abstract
A femtosecond plasma imaging modality based on a new development of ultrafast electron microscope is introduced. We investigated the laser-induced formation of high-temperature electron microplasmas and their subsequent non-equilibrium evolution. Based on a straightforward field imaging principle, we directly retrieve detailed information about the plasma dynamics, including plasma wave structures, particle densities, and temperatures. We discover that directly subjected to a strong magnetic field, the photo-generated microplasmas manifest in novel transient cyclotron echoes and form new wave states across a broad range of field strengths and different laser fluences. Intriguingly, the transient cyclotron waves morph into a higher frequency upper-hybrid wave mode with the dephasing of local cyclotron dynamics. The quantitative real-space characterizations of the non-equilibrium plasma systems demonstrate the feasibilities of a new microscope system in studying the plasma dynamics or transient electric fields with high spatiotemporal resolutions.
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Affiliation(s)
- Shuaishuai Sun
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - Xiaoyi Sun
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - Daniel Bartles
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - Elliot Wozniak
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - Joseph Williams
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
| | - Peng Zhang
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824, USA
| | - Chong-Yu Ruan
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
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7
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Xiong X, Zhou Y, Luo Y, Li X, Bosman M, Ang LK, Zhang P, Wu L. Plasmon-Enhanced Resonant Photoemission Using Atomically Thick Dielectric Coatings. ACS NANO 2020; 14:8806-8815. [PMID: 32567835 DOI: 10.1021/acsnano.0c03406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
By proposing an atomically thick dielectric coating on a metal nanoemitter, we theoretically show that the optical field tunneling of ultrafast-laser-induced photoemission can occur at an ultralow incident field strength of 0.03 V/nm. This coating strongly confines plasmonic fields and provides secondary field enhancement beyond the geometrical plasmon field enhancement effect, which can substantially reduce the barrier and enable more efficient photoemission. We numerically demonstrate that a 1 nm thick layer of SiO2 around a Au-nanopyramid will enhance the resonant photoemission current density by 2 orders of magnitude, where the transition from multiphoton absorption to optical field tunneling is accessed at an incident laser intensity at least 10 times lower than that of the bare nanoemitter. The effects of the coating properties such as refractive index, thickness, and geometrical settings are studied, and tunable photoemission is numerically demonstrated by using different ultrafast lasers. Our approach can also directly be extended to nonmetal emitters, to-for example-2D material coatings, and to plasmon-induced hot carrier generation.
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Affiliation(s)
- Xiao Xiong
- Institute of High Performance Computing, Agency for Science, Technology, and Research (A*STAR), 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632
| | - Yang Zhou
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824-1226, United States
| | - Yi Luo
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824-1226, United States
| | - Xiang Li
- Leadmicro Nano Technology Co., Ltd, 7 Xingchuang Road, Wuxi 214000, China
| | - Michel Bosman
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575
- Institute of Materials Research and Engineering, Agency for Science, Technology, and Research (A*STAR), 2 Fusionopolis Way, Singapore 138634
| | - Lay Kee Ang
- SUTD-MIT International Design Center, Science, Mathematics and Technology Cluster, Singapore University of Technology and Design (SUTD), 8 Somapah Road, Singapore 487372
| | - Peng Zhang
- Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824-1226, United States
| | - Lin Wu
- Institute of High Performance Computing, Agency for Science, Technology, and Research (A*STAR), 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632
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A Visible and Near-IR Tunnel Photosensor with a Nanoscale Metal Emitter: The Effect of Matching of Hot Electrons Localization Zones and a Strong Electrostatic Field. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9245356] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The results of the research and design of a novel vacuum photosensor with a planar molybdenum blade structure are presented. The advanced prototype implements the principle of an increasing penetrability of the Schottky barrier for the metal–vacuum interfaces under the action of an external strong electrostatic field. Theoretical and experimental substantiation of the photosensor performance in a wide range of wavelengths (from 430 to 680 nm and from 800 to 1064 nm) beyond the threshold of the classical photoelectric effect is given. The finite element method was applied to calculate distribution of the optical and electrostatic fields inside the photosensor structure. The sensor current-to-light response was studied using the periodic pulsed irradiation with the tunable wavelength. It was shown that the nanoscale localization zones of two types are formed near the surface of the blade tip: the zone of an increased concentration of hot electrons localized inside the molybdenum blade, and the zone with an increased strength of the external electrostatic field localized outside the blade. In general, the mutual positions of these zones may not coincide, whereas the position of the first-type localization zone significantly varies with the changes in the wavelength of the irradiating light. This causes features in the spectrum of the quantum yield of the photosensor such as expressed non-monotonic behavior and occurrence of sharp dips. The design of the photosensor that provides matching of the positions for both types of localization zones was proposed; the manufactured prototypes of the designed device were experimentally studied. In the designed photosensor, the ballistic transport of photoelectrons in the vacuum gap with a strong field provides a possibility for the creation of ultra-fast optoelectronic devices, such as modulators, detectors, and generators.
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Shen Y, Xing Y, Wang H, Xu N, Gong L, Wen J, Chen X, Zhan R, Chen H, Zhang Y, Liu F, Chen J, She J, Deng S. An in situ characterization technique for electron emission behavior under a photo-electric-common-excitation field: study on the vertical few-layer graphene individuals. NANOTECHNOLOGY 2019; 30:445202. [PMID: 31349235 DOI: 10.1088/1361-6528/ab3609] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The in situ characterization on the individuals offers an effective way to explore the dynamic behaviors and underlying physics of materials at the nanoscale, and this is of benefit for actual applications. In the field of vacuum micro-nano electronics, the existing in situ techniques can obtain the material information such as structure, morphology and composition in the process of electron emission driven by a single source of excitation. However, the relevant process and mechanism become more complicated when two or more excitation sources are commonly acted on the emitters. In this paper, we present an in situ nano characterization technique to trigger and record the electron emission behavior under the photo-electric-common-excitation multiple physical fields. Specifically, we probed into the in situ electron emission from an individual vertical few-layer graphene (vFLG) emitter under a laser-plus-electrostatic driving field. Electrons were driven out from the vFLG's emission edge, operated in situ under an external electrostatic field coupled with a 785 nm continuous-wave laser-triggered optical field. The incident light has been demonstrated to significantly improve the electron emission properties of graphene, which were recorded as an obvious decrease of the turn-on voltage, a higher emission current by factor of 35, as well as a photo-response on-off ratio as high as 5. More importantly, during their actual electron emission process, a series of in situ characterizations such as SEM observation and Raman spectra were used to study the structure, composition and even real-time Raman frequency changes of the emitters. These information can further reveal the key factors for the electron emission properties, such as field enhancement, work function and real-time surface temperature. Thereafter, the emission mechanism of vFLG in this study has been semi-quantitatively demonstrated to be the two concurrent processes of photon-assisted thermal enhanced field emission and photo field emission.
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Affiliation(s)
- Yan Shen
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
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10
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Lang P, Song X, Ji B, Tao H, Dou Y, Gao X, Hao Z, Lin J. Spatial- and energy-resolved photoemission electron from plasmonic nanoparticles in multiphoton regime. OPTICS EXPRESS 2019; 27:6878-6891. [PMID: 30876264 DOI: 10.1364/oe.27.006878] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 01/21/2019] [Indexed: 05/27/2023]
Abstract
Spatial-resolved photoelectron spectra have been observed from plasmonic metallic nanostructure and flat metal surface by a combination of time-of-flight photoemission electron microscope and femtosecond laser oscillator. The photoemission's main contribution is at localized 'hot spots,' where the plasmonic effect dominates and multiphoton photoemission is confirmed as the responsible mechanism for emission in both samples. Photoelectron spectra from hot spots exponentially decay in high energy regimes, smearing out the Fermi edge in Au flat surface. This phenomenon is explained by the emergence of above threshold photoemission that is induced by plasmonic effect; other competing mechanisms are ruled out. It is the first time that we have observed the emergence of high kinetic energy photoelectron in weak field region around 'hot spot.' We attribute the emergence of high kinetic energy photoelectron to the drifting of the liberated electron from plasmonic hot spot and driven by the gradient of plasmonic field.
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11
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Shen Y, Chen H, Xu N, Xing Y, Wang H, Zhan R, Gong L, Wen J, Zhuang C, Chen X, Wang X, Zhang Y, Liu F, Chen J, She J, Deng S. A Plasmon-Mediated Electron Emission Process. ACS NANO 2019; 13:1977-1989. [PMID: 30747519 DOI: 10.1021/acsnano.8b08444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Light-driven electron emission plays an important role in modern optoelectronic devices. However, such a process usually requires a light field with either a high intensity or a high frequency, which is not favorable for its implementations and difficult for its integrations. To solve these issues, we propose to combine plasmonic nanostructures with nanoelectron emitters of low work function. In such a heterostructure, hot electrons generated by plasmon resonances upon light excitation can be directly injected into the adjacent emitter, which can subsequently be emitted into the vacuum. Electron emission of high efficiency can be obtained with light fields of moderate intensities and visible wavelengths, which is a plasmon-mediated electron emission (PMEE) process. We have demonstrated our proposed design using a gold-on-graphene (Au-on-Gr) nanostructure, which can have electron emission with light intensity down to 73 mW·cm-2. It should be noted that the field electron emission is not involved in such a PMEE process. This proposal is of interest for applications including cold-cathode electron sources, advanced photocathodes, and micro- and nanoelectronic devices relying on free electrons.
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Affiliation(s)
- Yan Shen
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Huanjun Chen
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Ningsheng Xu
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Yang Xing
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Hao Wang
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Runze Zhan
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Li Gong
- Instrumental Analysis & Research Center , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Jinxiu Wen
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Chao Zhuang
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Xuexian Chen
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Ximiao Wang
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Yu Zhang
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Fei Liu
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Jun Chen
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Juncong She
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
| | - Shaozhi Deng
- State Key Laboratory of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology , Sun Yat-sen University , Guangzhou 510275 , People's Republic of China
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12
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Zimmermann P, Hötger A, Fernandez N, Nolinder A, Müller K, Finley JJ, Holleitner AW. Toward Plasmonic Tunnel Gaps for Nanoscale Photoemission Currents by On-Chip Laser Ablation. NANO LETTERS 2019; 19:1172-1178. [PMID: 30608702 DOI: 10.1021/acs.nanolett.8b04612] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We demonstrate that prestructured metal nanogaps can be shaped on-chip to below 10 nm by femtosecond laser ablation. We explore the plasmonic properties and the nonlinear photocurrent characteristics of the formed tunnel junctions. The photocurrent can be tuned from multiphoton absorption toward the laser-induced strong-field tunneling regime in the nanogaps. We demonstrate that a unipolar ballistic electron current is achieved by designing the plasmonic junctions to be asymmetric, which allows ultrafast electronics on the nanometer scale.
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Affiliation(s)
- Philipp Zimmermann
- Walter Schottky Institute and Physics Department , Technical University of Munich , Am Coulombwall 4a , Garching 85748 , Germany
- Nanosystems Initiative Munich (NIM) , Schellingstr. 4 , Munich 80799 , Germany
| | - Alexander Hötger
- Walter Schottky Institute and Physics Department , Technical University of Munich , Am Coulombwall 4a , Garching 85748 , Germany
| | - Noelia Fernandez
- Walter Schottky Institute and Physics Department , Technical University of Munich , Am Coulombwall 4a , Garching 85748 , Germany
| | - Anna Nolinder
- Walter Schottky Institute and Physics Department , Technical University of Munich , Am Coulombwall 4a , Garching 85748 , Germany
| | - Kai Müller
- Walter Schottky Institute and Physics Department , Technical University of Munich , Am Coulombwall 4a , Garching 85748 , Germany
| | - Jonathan J Finley
- Walter Schottky Institute and Physics Department , Technical University of Munich , Am Coulombwall 4a , Garching 85748 , Germany
- Nanosystems Initiative Munich (NIM) , Schellingstr. 4 , Munich 80799 , Germany
| | - Alexander W Holleitner
- Walter Schottky Institute and Physics Department , Technical University of Munich , Am Coulombwall 4a , Garching 85748 , Germany
- Nanosystems Initiative Munich (NIM) , Schellingstr. 4 , Munich 80799 , Germany
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13
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Lang P, Ji B, Song X, Dou Y, Tao H, Gao X, Hao Z, Lin J. Ultrafast switching of photoemission electron through quantum pathways interference in metallic nanostructure. OPTICS LETTERS 2018; 43:5721-5724. [PMID: 30499977 DOI: 10.1364/ol.43.005721] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 10/20/2018] [Indexed: 06/09/2023]
Abstract
The localized photoemission electron originating from the plasmonic "hot spots" in a metallic bowtie nanostructure can be separately switched on and off by adjusting the relative time delay between two orthogonally polarized laser pulses. The demonstrated femtosecond timing, nanometric spatial switching of multiphoton photoemission results from the interference of quantum pathways. Energy resolved measurement of the photoemission electrons further shows that the quantum pathway interference mechanism applies to control all the liberated electrons. The experimental results also show that the probability of electron emission through the quantum pathways from a plasmonic hot spot is determined by the localized emission response to the two incident laser pulses. These findings are of importance for controlling photoemission in ultrahigh spatiotemporal resolution in metallic plasmonic nanostructures.
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14
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Mohan K, Tyagi A, Mondal PP. Note: Multi-sheet light enables optical interference lithography. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:066106. [PMID: 29960546 DOI: 10.1063/1.5022499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We propose and demonstrate a modified spatial filter-based single-shot lithography technique for fabricating an array of microfluidic channels. This is achieved by illuminating the photopolymer specimen with a multiple light sheet (MLS) pattern. Modified spatial filtering is employed in a cylindrical lens system to generate the MLS pattern. The transmission window [the difference (α - β) angle] of the spatial filter determines the characteristics of the pattern and the fabricated microfluidic channel array. After exposing to a negative photoresist (DPHPA monomer with rose bengal as the photoinitiator), this gives rise to an array of micro-fluidic channels (post development process). We studied the effect of micro-channel geometry (channel width, inter-channel separation, and aspect ratio) for varying exposure times that show near-linear dependence. The results show that the fabricated array has 7 prominent channels with an individual channel width and inter-channel separation of approximately 5 μm and 12 μm, respectively. The proposed technique enables selective plane patterning and reduces the overall cost for large-scale production.
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Affiliation(s)
- Kavya Mohan
- Nanobioimaging Laboratory, Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012, India
| | - Ayush Tyagi
- Department of Physics, Indian Institute of Science and Education, Mohali, India
| | - Partha Pratim Mondal
- Nanobioimaging Laboratory, Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012, India
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15
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Mårsell E, Boström E, Harth A, Losquin A, Guo C, Cheng YC, Lorek E, Lehmann S, Nylund G, Stankovski M, Arnold CL, Miranda M, Dick KA, Mauritsson J, Verdozzi C, L'Huillier A, Mikkelsen A. Spatial Control of Multiphoton Electron Excitations in InAs Nanowires by Varying Crystal Phase and Light Polarization. NANO LETTERS 2018; 18:907-915. [PMID: 29257889 DOI: 10.1021/acs.nanolett.7b04267] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We demonstrate the control of multiphoton electron excitations in InAs nanowires (NWs) by altering the crystal structure and the light polarization. Using few-cycle, near-infrared laser pulses from an optical parametric chirped-pulse amplification system, we induce multiphoton electron excitations in InAs nanowires with controlled wurtzite (WZ) and zincblende (ZB) segments. With a photoemission electron microscope, we show that we can selectively induce multiphoton electron emission from WZ or ZB segments of the same wire by varying the light polarization. Developing ab initio GW calculations of first to third order multiphoton excitations and using finite-difference time-domain simulations, we explain the experimental findings: While the electric-field enhancement due to the semiconductor/vacuum interface has a similar effect for all NW segments, the second and third order multiphoton transitions in the band structure of WZ InAs are highly anisotropic in contrast to ZB InAs. As the crystal phase of NWs can be precisely and reliably tailored, our findings open up for new semiconductor optoelectronics with controllable nanoscale emission of electrons through vacuum or dielectric barriers.
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Affiliation(s)
- Erik Mårsell
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Emil Boström
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Anne Harth
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Arthur Losquin
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Chen Guo
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Yu-Chen Cheng
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Eleonora Lorek
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Sebastian Lehmann
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Gustav Nylund
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Martin Stankovski
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Cord L Arnold
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Miguel Miranda
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Kimberly A Dick
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Johan Mauritsson
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Claudio Verdozzi
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Anne L'Huillier
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
| | - Anders Mikkelsen
- Department of Physics, Lund University , P.O. Box 118, 221 00 Lund, Sweden
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16
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Bisharat DJ, Sievenpiper DF. Guiding Waves Along an Infinitesimal Line between Impedance Surfaces. PHYSICAL REVIEW LETTERS 2017; 119:106802. [PMID: 28949164 DOI: 10.1103/physrevlett.119.106802] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Indexed: 06/07/2023]
Abstract
We present a new electromagnetic mode that forms at the interface between two planar surfaces laid side by side in free space, effectively guiding energy along an infinitesimal, one-dimensional line. It is shown that this mode occurs when the boundaries have complementary surface impedances, and it is possible to control the mode confinement by altering their values correspondingly. The mode exhibits singular field enhancement, broad bandwidth, direction-dependent polarization, and robustness to certain defects. As a proof of concept, experimental results in the microwave regime are provided using patterned conducting sheets. Our proposed effective-medium-based approach is general, however, thus allowing for potential implementation up to optical frequencies. Our system is promising for applications including integrated photonics, sensing, switching, chiral quantum coupling, and reconfigurable waveguides.
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Affiliation(s)
- Dia'aaldin J Bisharat
- Department of Electronic Engineering, City University of Hong Kong, Kowloon, Hong Kong, China
- Electrical and Computer Engineering Department, University of California, San Diego, California 92093, USA
| | - Daniel F Sievenpiper
- Electrical and Computer Engineering Department, University of California, San Diego, California 92093, USA
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17
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Song B, Yao Y, Groenewald RE, Wang Y, Liu H, Wang Y, Li Y, Liu F, Cronin SB, Schwartzberg AM, Cabrini S, Haas S, Wu W. Probing Gap Plasmons Down to Subnanometer Scales Using Collapsible Nanofingers. ACS NANO 2017; 11:5836-5843. [PMID: 28599108 DOI: 10.1021/acsnano.7b01468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Gap plasmonic nanostructures are of great interest due to their ability to concentrate light into small volumes. Theoretical studies, considering quantum mechanical effects, have predicted the optimal spatial gap between adjacent nanoparticles to be in the subnanometer regime in order to achieve the strongest possible field enhancement. Here, we present a technology to fabricate gap plasmonic structures with subnanometer resolution, high reliability, and high throughput using collapsible nanofingers. This approach enables us to systematically investigate the effects of gap size and tunneling barrier height. The experimental results are consistent with previous findings as well as with a straightforward theoretical model that is presented here.
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Affiliation(s)
- Boxiang Song
- Ming Hsieh Department of Electrical Engineering, University of Southern California , Los Angeles, California 90089, United States
| | - Yuhan Yao
- Ming Hsieh Department of Electrical Engineering, University of Southern California , Los Angeles, California 90089, United States
| | - Roelof E Groenewald
- Department of Physics and Astronomy, University of Southern California , Los Angeles, California 90089, United States
| | - Yunxiang Wang
- Ming Hsieh Department of Electrical Engineering, University of Southern California , Los Angeles, California 90089, United States
| | - He Liu
- Ming Hsieh Department of Electrical Engineering, University of Southern California , Los Angeles, California 90089, United States
| | - Yifei Wang
- Ming Hsieh Department of Electrical Engineering, University of Southern California , Los Angeles, California 90089, United States
| | - Yuanrui Li
- Ming Hsieh Department of Electrical Engineering, University of Southern California , Los Angeles, California 90089, United States
| | - Fanxin Liu
- Department of Applied Physics, Zhejiang University of Technology , Hangzhou, Zhejiang 310023, China
| | - Stephen B Cronin
- Ming Hsieh Department of Electrical Engineering, University of Southern California , Los Angeles, California 90089, United States
| | - Adam M Schwartzberg
- Molecular Foundry, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Stefano Cabrini
- Molecular Foundry, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Stephan Haas
- Department of Physics and Astronomy, University of Southern California , Los Angeles, California 90089, United States
| | - Wei Wu
- Ming Hsieh Department of Electrical Engineering, University of Southern California , Los Angeles, California 90089, United States
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