1
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Sebastián-Vicente C, Imbrock J, Laubrock S, Caballero-Calero O, García-Cabañes A, Carrascosa M. All-Optical Domain Inversion in LiNbO 3 Crystals by Visible Continuous-Wave Laser Irradiation. ACS PHOTONICS 2024; 11:2624-2636. [PMID: 39036060 PMCID: PMC11258989 DOI: 10.1021/acsphotonics.4c00336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 05/10/2024] [Accepted: 06/07/2024] [Indexed: 07/23/2024]
Abstract
LiNbO3 is a distinguished multifunctional material where ferroelectric domain engineering is of paramount importance. This degree of freedom of the spontaneous polarization remarkably enhances the applicability of LiNbO3, for instance, in photonics. In this work, we report the first method for all-optical domain inversion of LiNbO3 crystals using continuous-wave visible light. While we focus mainly on iron-doped LiNbO3, the applicability of the method is also showcased in undoped congruent LiNbO3. The technique is simple, cheap, and readily accessible. It relies on ubiquitous elements: a light source with low/moderate intensity, basic optics, and a conductive surrounding medium, e.g., water. Light-induced domain inversion is unequivocally demonstrated and characterized by combination of several experimental techniques: selective chemical etching, surface topography profilometry, pyroelectric trapping of charged microparticles, scanning electron microscopy, and 3D Čerenkov microscopy. The influence of light intensity, exposure time, laser spot size, and surrounding medium is thoroughly studied. To explain all-optical domain inversion, we propose a novel physical mechanism based on an anomalous interplay between the bulk photovoltaic effect and external electrostatic screening. Overall, our all-optical method offers straightforward implementation of LiNbO3 ferroelectric domain engineering, potentially sparking new research endeavors aimed at novel optoelectronic applications of photovoltaic LiNbO3 platforms.
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Affiliation(s)
- Carlos Sebastián-Vicente
- Departamento
de Física de Materiales, Universidad
Autónoma de Madrid, 28049 Madrid, Spain
- Instituto
Nicolás Cabrera, Universidad Autónoma
de Madrid, 28049 Madrid, Spain
| | - Jörg Imbrock
- Institute
of Applied Physics, University of Münster, Corrensstr. 2, 48149 Münster, Germany
| | - Simon Laubrock
- Institute
of Applied Physics, University of Münster, Corrensstr. 2, 48149 Münster, Germany
| | - Olga Caballero-Calero
- Instituto
de Micro y Nanotecnología, IMN-CNM,
CSIC (CEI UAM+CSIC) Isaac Newton, 8, Tres Cantos, E-28760 Madrid, Spain
| | - Angel García-Cabañes
- Departamento
de Física de Materiales, Universidad
Autónoma de Madrid, 28049 Madrid, Spain
- Instituto
Nicolás Cabrera, Universidad Autónoma
de Madrid, 28049 Madrid, Spain
| | - Mercedes Carrascosa
- Departamento
de Física de Materiales, Universidad
Autónoma de Madrid, 28049 Madrid, Spain
- Instituto
Nicolás Cabrera, Universidad Autónoma
de Madrid, 28049 Madrid, Spain
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2
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Maity K, Dayen JF, Doudin B, Gumeniuk R, Kundys B. Graphene Magnetoresistance Control by Photoferroelectric Substrate. ACS NANO 2024. [PMID: 38284570 DOI: 10.1021/acsnano.3c07277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2024]
Abstract
Ultralow dimensionality of 2D layers magnifies their sensitivity to adjacent charges enabling even postprocessing electric control of multifunctional structures. However, functionalizing 2D layers remains an important challenge for on-demand device-property exploitation. Here we report that an electrical and even fully optical way to control and write modifications to the magnetoresistive response of CVD-deposited graphene is achievable through the electrostatics of the photoferroelectric substrate. For electrical control, the ferroelectric polarization switch modifies graphene magnetoresistance by 67% due to a Fermi level shift with related modification in charge mobility. A similar function is also attained entirely by bandgap light due to the substrate photovoltaic effect. Moreover, an all-optical way to imprint and recover graphene magnetoresistance by light is reported as well as magnetic control of graphene transconductance. These findings extend photoferroelectric control in 2D structures to magnetic dimensions and advance wireless operation for sensors and field-effect transistors.
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Affiliation(s)
- Krishna Maity
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, 23 rue du Loess, Strasbourg F-67000, France
| | - Jean-François Dayen
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, 23 rue du Loess, Strasbourg F-67000, France
| | - Bernard Doudin
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, 23 rue du Loess, Strasbourg F-67000, France
| | - Roman Gumeniuk
- Institut für Experimentelle Physik, TU Bergakademie Freiberg, Leipziger Str. 23, Freiberg 09596, Germany
| | - Bohdan Kundys
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, 23 rue du Loess, Strasbourg F-67000, France
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3
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Katiyar AK, Hoang AT, Xu D, Hong J, Kim BJ, Ji S, Ahn JH. 2D Materials in Flexible Electronics: Recent Advances and Future Prospectives. Chem Rev 2024; 124:318-419. [PMID: 38055207 DOI: 10.1021/acs.chemrev.3c00302] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Flexible electronics have recently gained considerable attention due to their potential to provide new and innovative solutions to a wide range of challenges in various electronic fields. These electronics require specific material properties and performance because they need to be integrated into a variety of surfaces or folded and rolled for newly formatted electronics. Two-dimensional (2D) materials have emerged as promising candidates for flexible electronics due to their unique mechanical, electrical, and optical properties, as well as their compatibility with other materials, enabling the creation of various flexible electronic devices. This article provides a comprehensive review of the progress made in developing flexible electronic devices using 2D materials. In addition, it highlights the key aspects of materials, scalable material production, and device fabrication processes for flexible applications, along with important examples of demonstrations that achieved breakthroughs in various flexible and wearable electronic applications. Finally, we discuss the opportunities, current challenges, potential solutions, and future investigative directions about this field.
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Affiliation(s)
- Ajit Kumar Katiyar
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Anh Tuan Hoang
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Duo Xu
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Juyeong Hong
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Beom Jin Kim
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Seunghyeon Ji
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
| | - Jong-Hyun Ahn
- School of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, Republic of Korea
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4
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Serebrennikova SI, Kopylova DS, Gladush YG, Krasnikov DV, Mailis S, Nasibulin AG. Photogating interfacial effects in carbon nanotube-based transistors on a Si/SiO 2 substrate toward highly sensitive photodetection. NANOSCALE 2023; 15:19351-19358. [PMID: 38013470 DOI: 10.1039/d3nr04451c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Single-walled carbon nanotubes (SWCNTs) are considered to be promising material platforms for various photodetectors (including phototransistors) due to their unique optoelectrical properties (e.g., high mobility and a wide variety of bandgap values). Herein, we present highly sensitive phototransistors which utilised sparse networks of SWCNTs on a silicon/silica substrate and operated by means of the photogating effect. The response of SWCNTs to photo-induced electrostatic charges (photogating effect) was highly dependent on the conductivity type of the channel, which was "metallic" or "semiconducting", depending on the SWCNT density. We determined the performance of these transistors depending on the characteristics of the substrate and conductivity type of the SWCNT channel. The optimized configuration of phototransistors with a channel comprising a sparse network of SWCNTs permitted improvement in the specific detectivity and relative response compared with previously reported photodetectors based on graphene and carbon nanotubes. We demonstrated an absolute responsivity of ∼60 A W-1 at an incident light power of ∼2 nW, specific detectivity of 7.8 × 1011 cm·Hz1/2 W-1, and response time of 300 μs. These data revealed the high potential of photogating-based SWCNTs detectors for extremely weak signals with a high signal-to-noise ratio.
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Affiliation(s)
| | - Daria S Kopylova
- Skolkovo Institute of Science and Technology, Nobel 3, 121205, Moscow, Russia.
| | - Yuriy G Gladush
- Skolkovo Institute of Science and Technology, Nobel 3, 121205, Moscow, Russia.
| | - Dmitry V Krasnikov
- Skolkovo Institute of Science and Technology, Nobel 3, 121205, Moscow, Russia.
| | - Sakellaris Mailis
- Skolkovo Institute of Science and Technology, Nobel 3, 121205, Moscow, Russia.
| | - Albert G Nasibulin
- Skolkovo Institute of Science and Technology, Nobel 3, 121205, Moscow, Russia.
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5
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Maity K, Dayen JF, Doudin B, Gumeniuk R, Kundys B. Single Wavelength Operating Neuromorphic Device Based on a Graphene-Ferroelectric Transistor. ACS APPLIED MATERIALS & INTERFACES 2023; 15:55948-55956. [PMID: 37983566 DOI: 10.1021/acsami.3c10010] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
As global data generation continues to rise, there is an increasing demand for revolutionary in-memory computing methodologies and efficient machine learning solutions. Despite recent progress in electrical and electro-optical simulations of machine learning devices, the all-optical nonthermal function remains challenging, with single wavelength operation still elusive. Here we report on an optical and monochromatic way of neuromorphic signal processing for brain-inspired functions, eliminating the need for electrical pulses. Multilevel synaptic potentiation-depression cycles are successfully achieved optically by leveraging photovoltaic charge generation and polarization within the photoferroelectric substrate interfaced with the graphene sensor. Furthermore, the demonstrated low-power prototype device is able to reproduce exact signal profile of brain tissues yet with more than 2 orders of magnitude faster response. The reported properties should trigger all-optical and low power artificial neuromorphic development based on photoferroelectric structures.
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Affiliation(s)
- Krishna Maity
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, 23 rue du Loess, Strasbourg F-67000, France
| | - Jean-François Dayen
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, 23 rue du Loess, Strasbourg F-67000, France
| | - Bernard Doudin
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, 23 rue du Loess, Strasbourg F-67000, France
| | - Roman Gumeniuk
- Institut für Experimentelle Physik, TU Bergakademie Freiberg, Leipziger Str. 23, Freiberg 09596, Germany
| | - Bohdan Kundys
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, 23 rue du Loess, Strasbourg F-67000, France
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6
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Yang AJ, Wu L, Liu Y, Zhang X, Han K, Huang Y, Li S, Loh XJ, Zhu Q, Su R, Nan CW, Renshaw Wang X. Multifunctional Magnetic Oxide-MoS 2 Heterostructures on Silicon. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2302620. [PMID: 37227936 DOI: 10.1002/adma.202302620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/12/2023] [Indexed: 05/27/2023]
Abstract
Correlated oxides and related heterostructures are intriguing for developing future multifunctional devices by exploiting their exotic properties, but their integration with other materials, especially on Si-based platforms, is challenging. Here, van der Waals heterostructures of La0.7 Sr0.3 MnO3 (LSMO) , a correlated manganite perovskite, and MoS2 are demonstrated on Si substrates with multiple functions. To overcome the problems due to the incompatible growth process, technologies involving freestanding LSMO membranes and van der Waals force-mediated transfer are used to fabricate the LSMO-MoS2 heterostructures. The LSMO-MoS2 heterostructures exhibit a gate-tunable rectifying behavior, based on which metal-semiconductor field-effect transistors (MESFETs) with on-off ratios of over 104 can be achieved. The LSMO-MoS2 heterostructures can function as photodiodes displaying considerable open-circuit voltages and photocurrents. In addition, the colossal magnetoresistance of LSMO endows the LSMO-MoS2 heterostructures with an electrically tunable magnetoresponse at room temperature. This work not only proves the applicability of the LSMO-MoS2 heterostructure devices on Si-based platform but also demonstrates a paradigm to create multifunctional heterostructures from materials with disparate properties.
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Affiliation(s)
- Allen Jian Yang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Liang Wu
- Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093, China
| | - Yanran Liu
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Xinyu Zhang
- Faculty of Material Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan, 650093, China
| | - Kun Han
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, China
| | - Ying Huang
- State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang, 621010, China
| | - Shengyao Li
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Xian Jun Loh
- Institute of Materials Research and Engineering (IMRE), A*STAR, 2 Fusionopolis Way, Innovis, Singapore, 138634, Singapore
| | - Qiang Zhu
- Institute of Materials Research and Engineering (IMRE), A*STAR, 2 Fusionopolis Way, Innovis, Singapore, 138634, Singapore
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
| | - Rui Su
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 637371, Singapore
- MajuLab, International Joint Research Unit UMI 3654, CNRS, Université Côte d'Azur, Sorbonne Université, National University of Singapore, Nanyang Technological University, Singapore, 637371, Singapore
| | - Ce-Wen Nan
- State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Xiao Renshaw Wang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 637371, Singapore
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7
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Wu F, Chou CH, Tseng TY. CMOS-Compatible Memristor for Optoelectronic Neuromorphic Computing. NANOSCALE RESEARCH LETTERS 2022; 17:105. [PMID: 36342556 PMCID: PMC9640510 DOI: 10.1186/s11671-022-03744-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 11/02/2022] [Indexed: 06/16/2023]
Abstract
Optoelectronic memristor is a promising candidate for future light-controllable high-density storage and neuromorphic computing. In this work, light-tunable resistive switching (RS) characteristics are demonstrated in the CMOS process-compatible ITO/HfO2/TiO2/ITO optoelectronic memristor. The device shows an average of 79.24% transmittance under visible light. After electroforming, stable bipolar analog switching, data retention beyond 104 s, and endurance of 106 cycles are realized. An obvious current increase is observed under 405 nm wavelength light irradiation both in high and in low resistance states. The long-term potentiation of synaptic property can be achieved by both electrical and optical stimulation. Moreover, based on the optical potentiation and electrical depression of conductances, the simulated Hopfield neural network (HNN) is trained for learning the 10 × 10 pixels size image. The HNN can be successfully trained to recognize the input image with a training accuracy of 100% in 13 iterations. These results suggest that this optoelectronic memristor has a high potential for neuromorphic application.
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Affiliation(s)
- Facai Wu
- Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Chien-Hung Chou
- Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Tseung-Yuen Tseng
- Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan.
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8
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Pei Y, Yan L, Wu Z, Lu J, Zhao J, Chen J, Liu Q, Yan X. Artificial Visual Perception Nervous System Based on Low-Dimensional Material Photoelectric Memristors. ACS NANO 2021; 15:17319-17326. [PMID: 34541840 DOI: 10.1021/acsnano.1c04676] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The visual perception system is the most important system for human learning since it receives over 80% of the learning information from the outside world. With the exponential growth of artificial intelligence technology, there is a pressing need for high-energy and area-efficiency visual perception systems capable of processing efficiently the received natural information. Currently, memristors with their elaborate dynamics, excellent scalability, and information (e.g., visual, pressure, sound, etc.) perception ability exhibit tremendous potential for the application of visual perception. Here, we propose a fully memristor-based artificial visual perception nervous system (AVPNS) which consists of a quantum-dot-based photoelectric memristor and a nanosheet-based threshold-switching (TS) memristor. We use a photoelectric and a TS memristor to implement the synapse and leaky integrate-and-fire (LIF) neuron functions, respectively. With the proposed AVPNS we successfully demonstrate the biological image perception, integration and fire, as well as the biosensitization process. Furthermore, the self-regulation process of a speed meeting control system in driverless automobiles can be accurately and conceptually emulated by this system. Our work shows that the functions of the biological visual nervous system may be systematically emulated by a memristor-based hardware system, thus expanding the spectrum of memristor applications in artificial intelligence.
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Affiliation(s)
- Yifei Pei
- National-Local Joint Engineering Laboratory of New Energy Photovoltaic Devices, Key Laboratory of Brain-Like Neuromorphic Devices and Systems of Hebei Province, College of Electron and Information Engineering, Hebei University, Baoding 071002, P. R. China
| | - Lei Yan
- National-Local Joint Engineering Laboratory of New Energy Photovoltaic Devices, Key Laboratory of Brain-Like Neuromorphic Devices and Systems of Hebei Province, College of Electron and Information Engineering, Hebei University, Baoding 071002, P. R. China
| | - Zuheng Wu
- School of Integrated Circuits, Anhui University, Hefei, Anhui 230601, P. R. China
| | - Jikai Lu
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics of Chinese Academy of Sciences, Beijing, 100029, P. R. China
| | - Jianhui Zhao
- National-Local Joint Engineering Laboratory of New Energy Photovoltaic Devices, Key Laboratory of Brain-Like Neuromorphic Devices and Systems of Hebei Province, College of Electron and Information Engineering, Hebei University, Baoding 071002, P. R. China
| | - Jingsheng Chen
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Qi Liu
- Frontier Institute of Chip and System Fudan University Shanghai 200433, P. R. China
| | - Xiaobing Yan
- National-Local Joint Engineering Laboratory of New Energy Photovoltaic Devices, Key Laboratory of Brain-Like Neuromorphic Devices and Systems of Hebei Province, College of Electron and Information Engineering, Hebei University, Baoding 071002, P. R. China
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9
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Liu K, Lu F, Xu Y, Ma C. Investigation of optical absorption enhancement of plasmonic configuration by graphene on LiNbO 3-SiO 2structure. NANOTECHNOLOGY 2021; 33:045701. [PMID: 34649234 DOI: 10.1088/1361-6528/ac2fe6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 10/14/2021] [Indexed: 06/13/2023]
Abstract
A novel plasmonic structure is demonstrated by combining graphene with a planar LiNbO3thin layer, which is simple and easy to fabricate compared to the complex design of general graphene surface plasmons devices. Graphene from the chemical vapor deposition is investigated and characterized to be a continuous and uniform monolayer or fewlayer. LiNbO3capped by graphene layer show an extraordinary absorption enhancement in an attenuated total reflection (ATR) measurement at a wide bandwidth of 500-4000 cm-1, which can be explained by resonance absorption resulting from the coupling of graphene surface plasmons with optical modes of LiNbO3-SiO2Fabry-Perot cavity and LiNbO3planar waveguide. The simulation results are generally consistent with the ATR experimental results. The absorption spectra versus temperature of this plasmonic configuration is also investigated, which show that increasing the testing temperature not only highlights the atomic vibrational peaks of graphene, but also enhances the absorption at several characteristic absorption frequencies due to the enhanced coupling between the surface plamons excitations and the optical modes.
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Affiliation(s)
- Kaijing Liu
- School of Information Science and Engineering, Shandong University, Qingdao 266200, People's Republic of China
| | - Fei Lu
- School of Information Science and Engineering, Shandong University, Qingdao 266200, People's Republic of China
| | - Yuhang Xu
- School of Information Science and Engineering, Shandong University, Qingdao 266200, People's Republic of China
| | - Changdong Ma
- Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan 250100, People's Republic of China
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10
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Wang P, Wang J, Zheng Y, Shi H, Sun X, Liu W, Gao B. Reversible photoluminescence modulation of monolayer MoS 2 on a ferroelectric substrate by light irradiation and thermal annealing. Phys Chem Chem Phys 2021; 23:17265-17270. [PMID: 34346428 DOI: 10.1039/d1cp02248b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Monolayer semiconducting two-dimensional (2D) materials are strongly emerging materials for exploring the spin-valley coupling effect and fabricating novel optoelectronic devices due to their unique structural symmetry and band structures. Due to their atomic thickness, their excitonic optical response is highly sensitive to the dielectric environment. In this work, we present a novel approach to reversibly modulate the optical properties of monolayer molybdenum disulfide (MoS2) via changing the dielectric properties of the substrate by laser irradiation and thermal annealing. We chose LiNbO3 as the substrate and recorded the PL spectra of monolayer MoS2 on LiNbO3 substrates with positive (P+) and negative (P-) ferroelectric polarities. A distinct PL intensity of the A peak was observed due to opposite doping by surface charges. Under light irradiation, the PL intensity of monolayer MoS2 on P+ Fe2O3-doped LiNbO3 gradually decreased with time due to the reduction of intrinsic p-doping, which originated from the drift of photo-excited electrons under a spontaneous polarization field and accumulation on the surface. The PL intensity was found to be restored by thermal annealing which could erase the charge redistribution. This study provides a strategy to reversibly modulate the optical properties of monolayer 2D materials on top of ferroelectric materials.
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Affiliation(s)
- Peng Wang
- Institute of Modern Optics, School of Physics, Key Laboratory of Micro-Nano Optoelectronic Information System, Ministry of Industry and Information Technology, Key Laboratory of Micro-Optics and Photonic Technology of Heilongjiang Province, Harbin Institute of Technology, Harbin 150001, China.
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11
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He J, Chen R, Li Y, Chen S, Liu Z, Zhang Q. Graphene metalens with dynamic focusing and plane focusing in the terahertz range. APPLIED OPTICS 2021; 60:5752-5758. [PMID: 34263793 DOI: 10.1364/ao.427381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/03/2021] [Indexed: 06/13/2023]
Abstract
We theoretically propose a high-efficiency tunable metalens based on an ellipse-shaped perforated graphene metasurface. By optimizing the axial length ratio of the elliptical aperture, we find the elliptical aperture with high reflectivity over a broad band by means of observing the reflectivity at different frequencies. Then, varying the orientation of the elliptical aperture from 0° to 180°, the reflected wave can generate a continuous 2π range phase shift while keeping its amplitude high, which is necessary to achieve focusing. The metalens exhibits extraordinary tunability of focal length via uniformly changing the Fermi energy of graphene. The focus can be shifted above 72 µm with focusing efficiency reaching over 70%. In addition, the tunable metalens is also capable of broadband focusing modulation and plane focusing. The presented metalens exhibits outstanding focusing efficiency in dynamic focusing, thereby manifesting great practicability in dynamic imaging and robust stable imaging.
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12
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Liu K, Lu F, Xu Y, Ma C. Investigation of novel optical and waveguide characteristics for an air-graphene-LiNbO 3system. NANOTECHNOLOGY 2021; 32:215704. [PMID: 33545706 DOI: 10.1088/1361-6528/abe3b7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 02/05/2021] [Indexed: 06/12/2023]
Abstract
The optical characteristics of a planar thin film waveguide system composed of air-graphene-LiNbO3have been investigated. Monolayer or bilayer graphene of high quality are characterized by Raman spectroscopy, scanning electron microscopy and atomic force microscopy. The refractivity and reflectivity of the air-graphene-LiNbO3system are measured experimentally and compared with those of a LiNbO3waveguide by the prism coupling method. The reflectivity shows an overall decrease due to the lower transmittance for graphene on the LiNbO3substrate. The refractivity increases significantly at the wavelength of 1540 nm, which may be attributed to the generation of graphene surface plasmons excited by infrared radiation. A shaped air-graphene-LiNbO3waveguide is designed and simulated by Mode Solutions. The distribution of an optical field is performed and analyzed. The preparation of the proposed air-graphene-LiNbO3structure incorporates the commonly used chemical vapor deposition and thin film transfer techniques, and is compatible with existing optoelectronic integration processes, which can be employed for building various optical integrated devices.
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Affiliation(s)
- Kaijing Liu
- School of Information Science and Engineering, Shandong University, Qingdao 266200, People's Republic of China
| | - Fei Lu
- School of Information Science and Engineering, Shandong University, Qingdao 266200, People's Republic of China
| | - Yuhang Xu
- School of Information Science and Engineering, Shandong University, Qingdao 266200, People's Republic of China
| | - Changdong Ma
- Department of Radiation Oncology, Qilu Hospital of Shandong University, Jinan 250100, People's Republic of China
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13
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Zhang Z, Qi X, Zhang J, Guo C, Zhu Z. Graphene-enabled electrically tunability of metalens in the terahertz range. OPTICS EXPRESS 2020; 28:28101-28112. [PMID: 32988088 DOI: 10.1364/oe.401627] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 08/27/2020] [Indexed: 06/11/2023]
Abstract
In general, the functions of most metalenses cannot be adjusted dynamically after being fabricated. Here, we theoretically propose an electrically tunable metalens composed of single-layered and non-structured doped graphene loaded with ribbon-shaped metallic strip arrays with varied widths and gaps. The combination of the different widths and gaps can provide full phase coverage from 0 to 2π, which is necessary for a plane wave to be focused. The metalens exhibits obvious tunability of focal length and focal intensity as we varied the Fermi levels of the doped graphene at 10 THz. The focus is able to be shifted within 90.4 µm (∼3λ), with maximum focusing efficiency up to 61.62%. The tunable metalens can also be expanded to other operation frequencies from mid-infrared to terahertz range by properly designing structural parameters. The metalens consisting of nanostructured metal and non-structured graphene utilizes mature metal nanostructure preparation process and avoids the graphene processing, which consequently facilitates the fabrication and promotes the application.
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Chen TR, Lin YS, Wang YX, Lee WJ, Chen KHC, Chen JD. Graphene oxide-iridium nanocatalyst for the transformation of benzylic alcohols into carbonyl compounds. RSC Adv 2020; 10:4436-4445. [PMID: 35495275 PMCID: PMC9049132 DOI: 10.1039/c9ra10294a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 01/15/2020] [Indexed: 01/07/2023] Open
Abstract
A catalyst constructed from graphene oxide and iridium chloride exhibited high activity and reliability for the selective transformation of benzylic alcohols into aromatic aldehydes or ketones. Instead of thermal reaction, the transformation was performed under ultrasonication, a green process with low byproduct, high atomic yield and high selectivity. Experimental data obtained from spherical-aberration corrected field emission TEM (ULTRA-HRTEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy and Raman spectra confirm the nanostructure of the title complex. Noticeably, the activity and selectivity for the transformation of benzylic alcohols remained unchanged within 25 catalytic cycles. The average turn over frequency is higher than 5000 h−1, while the total turnover number (TON) is more than one hundred thousand, making it a high greenness and eco-friendly process for alcohol oxidation. Graphene oxide–iridium nanostructure act as a robust catalyst exhibiting high activity and reliability for the selective transformation of benzylic alcohols into aromatic aldehydes or ketones.![]()
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Affiliation(s)
- Tsun-Ren Chen
- Department of Applied Chemistry, National Ping Tung University Pingtong City Taiwan
| | - Yi-Sheng Lin
- Department of Applied Chemistry, National Ping Tung University Pingtong City Taiwan
| | - Yu-Xiang Wang
- Department of Applied Chemistry, National Ping Tung University Pingtong City Taiwan
| | - Wen-Jen Lee
- Department of Applied Physics, National Ping Tung University Pingtong City Taiwan
| | - Kelvin H-C Chen
- Department of Applied Chemistry, National Ping Tung University Pingtong City Taiwan
| | - Jhy-Der Chen
- Department of Chemistry, Chung-Yuan Christian University Chung-Li Taiwan
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Puerto A, Muñoz-Martín JF, Méndez A, Arizmendi L, García-Cabañes A, Agulló-López F, Carrascosa M. Synergy between pyroelectric and photovoltaic effects for optoelectronic nanoparticle manipulation. OPTICS EXPRESS 2019; 27:804-815. [PMID: 30696161 DOI: 10.1364/oe.27.000804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 11/30/2018] [Indexed: 06/09/2023]
Abstract
The combined action of the pyroelectric (PY) and photovoltaic (PV) effects, exhibited by z-cut LiNbO3:Fe substrates, has been investigated for particle trapping and patterning applications. The novel hybrid procedure provides new possibilities and versatility to optoelectronic manipulation on LiNbO3 substrates. It has allowed obtaining periodic and arbitrary 2D patterns whose particle density distribution is correlated with the light intensity profile but can be tuned through ΔT according to the relative strength of the PV and PY effects. A relevant result is that the PY and PV contributions compete for a ΔT range of 1-20 °C, very accessible for experiments. Moreover, the synergy of the PY and PV has provided two additional remarkable applications: i) A method to measure the PV field, key magnitude for photovoltaic optoelectronic tweezers. Using this method, the minimum field needed to obtain a particle pattern has been determined, resulting relatively high, E~60 kV/cm, and so, requiring highly doped crystals when only using the PV effect. ii) An strategy combining the PY and PV to get particle patterning in samples inactive for PV trapping when the PV field value is under that threshold.
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