1
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Milano G, Raffone F, Bejtka K, De Carlo I, Fretto M, Pirri FC, Cicero G, Ricciardi C, Valov I. Electrochemical rewiring through quantum conductance effects in single metallic memristive nanowires. Nanoscale Horiz 2024; 9:416-426. [PMID: 38224292 DOI: 10.1039/d3nh00476g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
Memristive devices have been demonstrated to exhibit quantum conductance effects at room temperature. In these devices, a detailed understanding of the relationship between electrochemical processes and ionic dynamic underlying the formation of atomic-sized conductive filaments and corresponding electronic transport properties in the quantum regime still represents a challenge. In this work, we report on quantum conductance effects in single memristive Ag nanowires (NWs) through a combined experimental and simulation approach that combines advanced classical molecular dynamics (MD) algorithms and quantum transport simulations (DFT). This approach provides new insights on quantum conductance effects in memristive devices by unravelling the intrinsic relationship between electronic transport and atomic dynamic reconfiguration of the nanofilment, by shedding light on deviations from integer multiples of the fundamental quantum of conductance depending on peculiar dynamic trajectories of nanofilament reconfiguration and on conductance fluctuations relying on atomic rearrangement due to thermal fluctuations.
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Affiliation(s)
- Gianluca Milano
- Advanced Materials Metrology and Life Sciences Division, INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, 10135 Torino, Italy.
| | - Federico Raffone
- Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
| | - Katarzyna Bejtka
- Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
- Centre for Sustainable Future Technologies, Istituto Italiano di Tecnologia, Via Livorno 60, 10144 Torino, Italy
| | - Ivan De Carlo
- Advanced Materials Metrology and Life Sciences Division, INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, 10135 Torino, Italy.
- Department of Electronics and Telecommunications, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Matteo Fretto
- Advanced Materials Metrology and Life Sciences Division, INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, 10135 Torino, Italy.
| | - Fabrizio Candido Pirri
- Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
- Centre for Sustainable Future Technologies, Istituto Italiano di Tecnologia, Via Livorno 60, 10144 Torino, Italy
| | - Giancarlo Cicero
- Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
| | - Carlo Ricciardi
- Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy.
| | - Ilia Valov
- Forschungszentrum Jülich, Institute of Electrochemistry and Energy System, WilhelmJohnen-Straße, 52428, Jülich, Germany
- "Acad. Evgeni Budevski" (IEE-BAS), Bulgarian Academy of Sciences (BAS), Acad. G. Bonchev Str., Block 10, 1113 Sofia, Bulgaria
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2
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Sahu TK, Kumar N, Chahal S, Jana R, Paul S, Mukherjee M, Tavabi AH, Datta A, Dunin-Borkowski RE, Valov I, Nayak A, Kumar P. Microwave synthesis of molybdenene from MoS 2. Nat Nanotechnol 2023; 18:1430-1438. [PMID: 37666941 PMCID: PMC10716048 DOI: 10.1038/s41565-023-01484-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 07/06/2023] [Indexed: 09/06/2023]
Abstract
Dirac materials are characterized by the emergence of massless quasiparticles in their low-energy excitation spectrum that obey the Dirac Hamiltonian. Known examples of Dirac materials are topological insulators, d-wave superconductors, graphene, and Weyl and Dirac semimetals, representing a striking range of fundamental properties with potential disruptive applications. However, none of the Dirac materials identified so far shows metallic character. Here, we present evidence for the formation of free-standing molybdenene, a two-dimensional material composed of only Mo atoms. Using MoS2 as a precursor, we induced electric-field-assisted molybdenene growth under microwave irradiation. We observe the formation of millimetre-long whiskers following screw-dislocation growth, consisting of weakly bonded molybdenene sheets, which, upon exfoliation, show metallic character, with an electrical conductivity of ~940 S m-1. Molybdenene when hybridized with two-dimensional h-BN or MoS2, fetch tunable optical and electronic properties. As a proof of principle, we also demonstrate applications of molybdenene as a surface-enhanced Raman spectroscopy platform for molecular sensing, as a substrate for electron imaging and as a scanning probe microscope cantilever.
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Affiliation(s)
- Tumesh Kumar Sahu
- Department of Physics, Indian Institute of Technology Patna, Bihar, India
- Department of Physics, Shri Ramdeobaba College of Engineering and Management, Nagpur, India
| | - Nishant Kumar
- Department of Physics, Indian Institute of Technology Patna, Bihar, India
| | - Sumit Chahal
- Department of Physics, Indian Institute of Technology Patna, Bihar, India
| | - Rajkumar Jana
- School of Chemical Sciences, Indian Association of Cultivation of Science, Kolkata, India
| | - Sumana Paul
- School of Chemical Sciences, Indian Association of Cultivation of Science, Kolkata, India
| | - Moumita Mukherjee
- School of Chemical Sciences, Indian Association of Cultivation of Science, Kolkata, India
| | - Amir H Tavabi
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, Jülich, Germany
| | - Ayan Datta
- School of Chemical Sciences, Indian Association of Cultivation of Science, Kolkata, India
| | - Rafal E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, Jülich, Germany
| | - Ilia Valov
- Peter Grünberg Institute (PGI-7), Forschungszentrum Jülich, Jülich, Germany.
- Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, Sofia, Bulgaria.
| | - Alpana Nayak
- Department of Physics, Indian Institute of Technology Patna, Bihar, India.
| | - Prashant Kumar
- Department of Physics, Indian Institute of Technology Patna, Bihar, India.
- Global Innovative Centre for Advanced Nanomaterials, The University of Newcastle, Newcastle, New South Wales, Australia.
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3
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Leonetti G, Fretto M, Pirri FC, De Leo N, Valov I, Milano G. Effect of electrode materials on resistive switching behaviour of NbO x-based memristive devices. Sci Rep 2023; 13:17003. [PMID: 37813937 PMCID: PMC10562416 DOI: 10.1038/s41598-023-44110-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 10/03/2023] [Indexed: 10/11/2023] Open
Abstract
Memristive devices that rely on redox-based resistive switching mechanism have attracted great attention for the development of next-generation memory and computing architectures. However, a detailed understanding of the relationship between involved materials, interfaces, and device functionalities still represents a challenge. In this work, we analyse the effect of electrode metals on resistive switching functionalities of NbOx-based memristive cells. For this purpose, the effect of Au, Pt, Ir, TiN, and Nb top electrodes was investigated in devices based on amorphous NbOx grown by anodic oxidation on a Nb substrate exploited also as counter electrode. It is shown that the choice of the metal electrode regulates electronic transport properties of metal-insulator interfaces, strongly influences the electroforming process, and the following resistive switching characteristics. Results show that the electronic blocking character of Schottky interfaces provided by Au and Pt metal electrodes results in better resistive switching performances. It is shown that Pt represents the best choice for the realization of memristive cells when the NbOx thickness is reduced, making possible the realization of memristive cells characterised by low variability in operating voltages, resistance states and with low device-to-device variability. These results can provide new insights towards a rational design of redox-based memristive cells.
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Affiliation(s)
- Giuseppe Leonetti
- Department of Applied Science and Technology (DISAT), Politecnico di Torino, C.So Duca Degli Abruzzi 24, 10129, Turin, Italy
| | - Matteo Fretto
- Advanced Materials Metrology and Life Sciences Division, Istituto Nazionale Di Ricerca Metrologica (INRiM), Strada Delle Cacce 91, 10135, Turin, Italy
| | - Fabrizio Candido Pirri
- Department of Applied Science and Technology (DISAT), Politecnico di Torino, C.So Duca Degli Abruzzi 24, 10129, Turin, Italy
| | - Natascia De Leo
- Advanced Materials Metrology and Life Sciences Division, Istituto Nazionale Di Ricerca Metrologica (INRiM), Strada Delle Cacce 91, 10135, Turin, Italy
| | - Ilia Valov
- Institute of Electrochemistry and Energy System, Forschungszentrum Jülich, WilhelmJohnen-Straße, 52428, Jülich, Germany.
- "Acad. Evgeni Budevski" IEE-BAS, Bulgarian Academy of Sciences (BAS), Acad. G. Bonchev Str, Block 10, 1113, Sofia, Bulgaria.
| | - Gianluca Milano
- Advanced Materials Metrology and Life Sciences Division, Istituto Nazionale Di Ricerca Metrologica (INRiM), Strada Delle Cacce 91, 10135, Turin, Italy.
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4
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Chen S, Zhang T, Tappertzhofen S, Yang Y, Valov I. Electrochemical-Memristor-Based Artificial Neurons and Synapses-Fundamentals, Applications, and Challenges. Adv Mater 2023; 35:e2301924. [PMID: 37199224 DOI: 10.1002/adma.202301924] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/22/2023] [Indexed: 05/19/2023]
Abstract
Artificial neurons and synapses are considered essential for the progress of the future brain-inspired computing, based on beyond von Neumann architectures. Here, a discussion on the common electrochemical fundamentals of biological and artificial cells is provided, focusing on their similarities with the redox-based memristive devices. The driving forces behind the functionalities and the ways to control them by an electrochemical-materials approach are presented. Factors such as the chemical symmetry of the electrodes, doping of the solid electrolyte, concentration gradients, and excess surface energy are discussed as essential to understand, predict, and design artificial neurons and synapses. A variety of two- and three-terminal memristive devices and memristive architectures are presented and their application for solving various problems is shown. The work provides an overview of the current understandings on the complex processes of neural signal generation and transmission in both biological and artificial cells and presents the state-of-the-art applications, including signal transmission between biological and artificial cells. This example is showcasing the possibility for creating bioelectronic interfaces and integrating artificial circuits in biological systems. Prospectives and challenges of the modern technology toward low-power, high-information-density circuits are highlighted.
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Affiliation(s)
- Shaochuan Chen
- Institute of Materials in Electrical Engineering 2 (IWE2), RWTH Aachen University, Sommerfeldstraße 24, 52074, Aachen, Germany
| | - Teng Zhang
- Key Laboratory of Microelectronic Devices and Circuits (MOE), School of Integrated Circuits, Peking University, Beijing, 100871, China
| | - Stefan Tappertzhofen
- Chair for Micro- and Nanoelectronics, Department of Electrical Engineering and Information Technology, TU Dortmund University, Martin-Schmeisser-Weg 4-6, D-44227, Dortmund, Germany
| | - Yuchao Yang
- Key Laboratory of Microelectronic Devices and Circuits (MOE), School of Integrated Circuits, Peking University, Beijing, 100871, China
- School of Electronic and Computer Engineering, Peking University, Shenzhen, 518055, China
- Center for Brain Inspired Intelligence, Chinese Institute for Brain Research (CIBR), Beijing, 102206, China
| | - Ilia Valov
- Peter Grünberg Institute (PGI-7), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425, Jülich, Germany
- Institute of Electrochemistry and Energy Systems "Acad. E. Budewski", Bulgarian Academy of Sciences, Acad. G. Bonchev 10, 1113, Sofia, Bulgaria
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5
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Song MK, Kang JH, Zhang X, Ji W, Ascoli A, Messaris I, Demirkol AS, Dong B, Aggarwal S, Wan W, Hong SM, Cardwell SG, Boybat I, Seo JS, Lee JS, Lanza M, Yeon H, Onen M, Li J, Yildiz B, Del Alamo JA, Kim S, Choi S, Milano G, Ricciardi C, Alff L, Chai Y, Wang Z, Bhaskaran H, Hersam MC, Strukov D, Wong HSP, Valov I, Gao B, Wu H, Tetzlaff R, Sebastian A, Lu W, Chua L, Yang JJ, Kim J. Recent Advances and Future Prospects for Memristive Materials, Devices, and Systems. ACS Nano 2023. [PMID: 37382380 DOI: 10.1021/acsnano.3c03505] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/30/2023]
Abstract
Memristive technology has been rapidly emerging as a potential alternative to traditional CMOS technology, which is facing fundamental limitations in its development. Since oxide-based resistive switches were demonstrated as memristors in 2008, memristive devices have garnered significant attention due to their biomimetic memory properties, which promise to significantly improve power consumption in computing applications. Here, we provide a comprehensive overview of recent advances in memristive technology, including memristive devices, theory, algorithms, architectures, and systems. In addition, we discuss research directions for various applications of memristive technology including hardware accelerators for artificial intelligence, in-sensor computing, and probabilistic computing. Finally, we provide a forward-looking perspective on the future of memristive technology, outlining the challenges and opportunities for further research and innovation in this field. By providing an up-to-date overview of the state-of-the-art in memristive technology, this review aims to inform and inspire further research in this field.
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Affiliation(s)
- Min-Kyu Song
- Department of Mechanical Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
- Research Laboratory of Electronics, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
| | - Ji-Hoon Kang
- Department of Mechanical Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
- Research Laboratory of Electronics, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
| | - Xinyuan Zhang
- Research Laboratory of Electronics, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
- Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
| | - Wonjae Ji
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Alon Ascoli
- Chair of Fundamentals of Electrical Engineering, Institute of Principles of Electrical and Electronic Engineering, Faculty of Electrical and Computer Engineering, School of Engineering Sciences, Technische Universität Dresden, Dresden 01069, Germany
| | - Ioannis Messaris
- Chair of Fundamentals of Electrical Engineering, Institute of Principles of Electrical and Electronic Engineering, Faculty of Electrical and Computer Engineering, School of Engineering Sciences, Technische Universität Dresden, Dresden 01069, Germany
| | - Ahmet Samil Demirkol
- Chair of Fundamentals of Electrical Engineering, Institute of Principles of Electrical and Electronic Engineering, Faculty of Electrical and Computer Engineering, School of Engineering Sciences, Technische Universität Dresden, Dresden 01069, Germany
| | - Bowei Dong
- Department of Materials, University of Oxford, Oxford OX1 3PH, United Kingdom
| | - Samarth Aggarwal
- Department of Materials, University of Oxford, Oxford OX1 3PH, United Kingdom
| | - Weier Wan
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Seok-Man Hong
- The School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | | | - Irem Boybat
- IBM Research Europe, 8803 Rüschlikon, Switzerland
| | - Jae-Sun Seo
- School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85281, United States
| | - Jang-Sik Lee
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Mario Lanza
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Hanwool Yeon
- School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Republic of Korea
| | - Murat Onen
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
| | - Ju Li
- Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
| | - Bilge Yildiz
- Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
| | - Jesús A Del Alamo
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
| | - Seyoung Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea
| | - Shinhyun Choi
- The School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Gianluca Milano
- Advanced Materials Metrology and Life Sciences Division, Istituto Nazionale di Ricerca Metrologica (INRiM), Strada delle Cacce, Torino 10135, Italy
| | - Carlo Ricciardi
- Department of Applied Science and Technology, Politecnico di Torino, c.so Duca degli Abruzzi, Torino 10129, Italy
| | - Lambert Alff
- Advanced Thin Film Technology Division, Institute of Materials Science, Technische Universität Darmstadt, Darmstadt 64287, Germany
| | - Yang Chai
- Department of Applied Physics, Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Zhongrui Wang
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Harish Bhaskaran
- Department of Materials, University of Oxford, Oxford OX1 3PH, United Kingdom
| | - Mark C Hersam
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
- Department of Electrical and Computer Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Dmitri Strukov
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - H-S Philip Wong
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Ilia Valov
- Research Centre Juelich, PGI-7, Wilhelm-Johnen-Str., Juelich 52425, Germany
- Institute of Electrochemistry and Energy Systems "Acad. E. Budewski", Bulgarain Academy of Sciences, "Acad. G. Bochev 10" str., 1113 Sofia, Bulgaria
| | - Bin Gao
- School of Integrated Circuits, Tsinghua University, Beijing 100084, China
| | - Huaqiang Wu
- School of Integrated Circuits, Tsinghua University, Beijing 100084, China
| | - Ronald Tetzlaff
- Chair of Fundamentals of Electrical Engineering, Institute of Principles of Electrical and Electronic Engineering, Faculty of Electrical and Computer Engineering, School of Engineering Sciences, Technische Universität Dresden, Dresden 01069, Germany
| | | | - Wei Lu
- Department of Electrical Engineering and Computer Science, The University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Leon Chua
- Department of Electrical Engineering and Computer Sciences, University of California Berkeley, Berkeley, California 94720, United States
| | - J Joshua Yang
- Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Jeehwan Kim
- Department of Mechanical Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
- Research Laboratory of Electronics, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
- Department of Materials Science and Engineering, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139, United States
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6
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Leonetti G, Fretto M, Bejtka K, Olivetti ES, Pirri FC, De Leo N, Valov I, Milano G. Resistive switching and role of interfaces in memristive devices based on amorphous NbO x grown by anodic oxidation. Phys Chem Chem Phys 2023; 25:14766-14777. [PMID: 37145117 DOI: 10.1039/d3cp01160g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Memristive devices based on the resistive switching mechanism are continuously attracting attention in the framework of neuromorphic computing and next-generation memory devices. Here, we report on a comprehensive analysis of the resistive switching properties of amorphous NbOx grown by anodic oxidation. Besides a detailed chemical, structural and morphological analysis of the involved materials and interfaces, the mechanism of switching in Nb/NbOx/Au resistive switching cells is discussed by investigating the role of metal-metal oxide interfaces in regulating electronic and ionic transport mechanisms. The resistive switching was found to be related to the formation/rupture of conductive nanofilaments in the NbOx layer under the action of an applied electric field, facilitated by the presence of an oxygen scavenger layer at the Nb/NbOx interface. Electrical characterization including device-to-device variability revealed an endurance >103 full-sweep cycles, retention >104 s, and multilevel capabilities. Furthermore, the observation of quantized conductance supports the physical mechanism of switching based on the formation of atomic-scale conductive filaments. Besides providing new insights into the switching properties of NbOx, this work also highlights the perspective of anodic oxidation as a promising method for the realization of resistive switching cells.
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Affiliation(s)
- Giuseppe Leonetti
- Politecnico di Torino, Department of Applied Science and Technology (DISAT), C.so Duca degli Abruzzi 24, 10129, Turin, Italy
| | - Matteo Fretto
- Istituto Nazionale di Ricerca Metrologica (INRiM), Advanced Materials Metrology and Life Science, Strada delle cacce 91, 10135 Turin, Italy.
| | - Katarzyna Bejtka
- Politecnico di Torino, Department of Applied Science and Technology (DISAT), C.so Duca degli Abruzzi 24, 10129, Turin, Italy
| | - Elena Sonia Olivetti
- Istituto Nazionale di Ricerca Metrologica (INRiM), Advanced Materials Metrology and Life Science, Strada delle cacce 91, 10135 Turin, Italy.
| | - Fabrizio Candido Pirri
- Politecnico di Torino, Department of Applied Science and Technology (DISAT), C.so Duca degli Abruzzi 24, 10129, Turin, Italy
| | - Natascia De Leo
- Istituto Nazionale di Ricerca Metrologica (INRiM), Advanced Materials Metrology and Life Science, Strada delle cacce 91, 10135 Turin, Italy.
| | - Ilia Valov
- Juelich, Institute of Electrochemistry and Energy System, Germany
- Acad. Evgeni Budevski (IEE-BAS, Bulgarian Academy of Sciences (BAS), Acad. G. Bonchev Str., Block 10, 1113 Sofia, Bulgaria
| | - Gianluca Milano
- Istituto Nazionale di Ricerca Metrologica (INRiM), Advanced Materials Metrology and Life Science, Strada delle cacce 91, 10135 Turin, Italy.
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7
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Cho DY, Kim KJ, Lee KS, Lübben M, Chen S, Valov I. Chemical Influence of Carbon Interface Layers in Metal/Oxide Resistive Switches. ACS Appl Mater Interfaces 2023; 15:18528-18536. [PMID: 36989142 PMCID: PMC10103050 DOI: 10.1021/acsami.3c00920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/21/2023] [Indexed: 06/19/2023]
Abstract
Thin layers introduced between a metal electrode and a solid electrolyte can significantly alter the transport of mass and charge at the interfaces and influence the rate of electrode reactions. C films embedded in functional materials can change the chemical properties of the host, thereby altering the functionality of the whole device. Using X-ray spectroscopies, here we demonstrate that the chemical and electronic structures in a representative redox-based resistive switching (RS) system, Ta2O5/Ta, can be tuned by inserting a graphene or ultrathin amorphous C layer. The results of the orbitalwise analyses of synchrotron Ta L3-edge, C K-edge, and O K-edge X-ray absorption spectroscopy showed that the C layers between Ta2O5 and Ta are significantly oxidized to form COx and, at the same time, oxidize the Ta layers with different degrees of oxidation depending on the distance: full oxidation at the nearest 5 nm Ta and partial oxidation in the next 15 nm Ta. The depth-resolved information on the electronic structure for each layer further revealed a significant modification of the band alignments due to C insertion. Full oxidation of the Ta metal near the C interlayer suggests that the oxygen-vacancy-related valence change memory mechanism for the RS can be suppressed, thereby changing the RS functionalities fundamentally. The knowledge on the origin of C-enhanced surfaces can be applied to other metal/oxide interfaces and used for the advanced design of memristive devices.
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Affiliation(s)
- Deok-Yong Cho
- IPIT
and Department of Physics, Jeonbuk National
University, Jeonju 54896, Republic of Korea
| | - Ki-jeong Kim
- Pohang
Accelerator Laboratory, Pohang 37673, Republic of Korea
| | - Kug-Seung Lee
- Pohang
Accelerator Laboratory, Pohang 37673, Republic of Korea
| | - Michael Lübben
- Peter
Gruenberg
Institute, Research Centre Juelich, Juelich 52425, Germany
| | - Shaochuan Chen
- IWE2, RWTH Aachen University, Sommerfed strasse 24, Aachen 52074, Germany
| | - Ilia Valov
- Peter
Gruenberg
Institute, Research Centre Juelich, Juelich 52425, Germany
- Institute
of Electrochemistry and Energy Systems “acad. E. Budewski”, Bulgarian Academy of Sciences, “acad. G Bonchev” street Bl.10, Sofia 1113, Bulgaria
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8
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Milano G, Miranda E, Fretto M, Valov I, Ricciardi C. Experimental and Modeling Study of Metal-Insulator Interfaces to Control the Electronic Transport in Single Nanowire Memristive Devices. ACS Appl Mater Interfaces 2022; 14:53027-53037. [PMID: 36396122 PMCID: PMC9716557 DOI: 10.1021/acsami.2c11022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 08/25/2022] [Indexed: 06/16/2023]
Abstract
Memristive devices relying on redox-based resistive switching mechanisms represent promising candidates for the development of novel computing paradigms beyond von Neumann architecture. Recent advancements in understanding physicochemical phenomena underlying resistive switching have shed new light on the importance of an appropriate selection of material properties required to optimize the performance of devices. However, despite great attention has been devoted to unveiling the role of doping concentration, impurity type, adsorbed moisture, and catalytic activity at the interfaces, specific studies concerning the effect of the counter electrode in regulating the electronic flow in memristive cells are scarce. In this work, the influence of the metal-insulator Schottky interfaces in electrochemical metallization memory (ECM) memristive cell model systems based on single-crystalline ZnO nanowires (NWs) is investigated following a combined experimental and modeling approach. By comparing and simulating the electrical characteristics of single NW devices with different contact configurations and by considering Ag and Pt electrodes as representative of electrochemically active and inert electrodes, respectively, we highlight the importance of an appropriate choice of electrode materials by taking into account the Schottky barrier height and interface chemistry at the metal-insulator interfaces. In particular, we show that a clever choice of metal-insulator interfaces allows to reshape the hysteretic conduction characteristics of the device and to increase the device performance by tuning its resistance window. These results obtained from single NW-based devices provide new insights into the selection criteria for materials and interfaces in connection with the design of advanced ECM cells.
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Affiliation(s)
- Gianluca Milano
- Advanced
Materials Metrology and Life Sciences Division, INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, 10135Torino, Italy
| | - Enrique Miranda
- Departament
d’Enginyeria Electrònica, Universitat Autònoma de Barcelona (UAB), 08193Cerdanyola del Vallès, Spain
| | - Matteo Fretto
- Advanced
Materials Metrology and Life Sciences Division, INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, 10135Torino, Italy
| | - Ilia Valov
- JARA—Fundamentals
for Future Information Technology, 52425Jülich, Germany
- Peter-Grünberg-Institut
(PGI 7), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425Jülich, Germany
| | - Carlo Ricciardi
- Department
of Applied Science and Technology, Politecnico
di Torino, C.so Duca degli Abruzzi 24, 10129Torino, Italy
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9
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Milano G, Aono M, Boarino L, Celano U, Hasegawa T, Kozicki M, Majumdar S, Menghini M, Miranda E, Ricciardi C, Tappertzhofen S, Terabe K, Valov I. Quantum Conductance in Memristive Devices: Fundamentals, Developments, and Applications. Adv Mater 2022; 34:e2201248. [PMID: 35404522 DOI: 10.1002/adma.202201248] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/23/2022] [Indexed: 06/14/2023]
Abstract
Quantum effects in novel functional materials and new device concepts represent a potential breakthrough for the development of new information processing technologies based on quantum phenomena. Among the emerging technologies, memristive elements that exhibit resistive switching, which relies on the electrochemical formation/rupture of conductive nanofilaments, exhibit quantum conductance effects at room temperature. Despite the underlying resistive switching mechanism having been exploited for the realization of next-generation memories and neuromorphic computing architectures, the potentialities of quantum effects in memristive devices are still rather unexplored. Here, a comprehensive review on memristive quantum devices, where quantum conductance effects can be observed by coupling ionics with electronics, is presented. Fundamental electrochemical and physicochemical phenomena underlying device functionalities are introduced, together with fundamentals of electronic ballistic conduction transport in nanofilaments. Quantum conductance effects including quantum mode splitting, stability, and random telegraph noise are analyzed, reporting experimental techniques and challenges of nanoscale metrology for the characterization of memristive phenomena. Finally, potential applications and future perspectives are envisioned, discussing how memristive devices with controllable atomic-sized conductive filaments can represent not only suitable platforms for the investigation of quantum phenomena but also promising building blocks for the realization of integrated quantum systems working in air at room temperature.
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Affiliation(s)
- Gianluca Milano
- Advanced Materials Metrology and Life Sciences Division, INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, Torino, 10135, Italy
| | - Masakazu Aono
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Luca Boarino
- Advanced Materials Metrology and Life Sciences Division, INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, Torino, 10135, Italy
| | - Umberto Celano
- IMEC, Kapeldreef 75, Heverlee, Leuven, B-3001, Belgium
- Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, Enschede, NB, 7522, The Netherlands
| | - Tsuyoshi Hasegawa
- Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan
| | - Michael Kozicki
- School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ, 85287, USA
| | - Sayani Majumdar
- VTT Technical Research Centre of Finland Ltd., VTT, P.O. Box 1000, Espoo, FI-02044, Finland
| | | | - Enrique Miranda
- Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona (UAB), Barcelona, 08193, Spain
| | - Carlo Ricciardi
- Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, Torino, 10129, Italy
| | - Stefan Tappertzhofen
- Chair for Micro- and Nanoelectronics, Department of Electrical Engineering and Information Technology, TU Dortmund University, Emil-Figge-Straße 68, D-44227, Dortmund, Germany
| | - Kazuya Terabe
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Ilia Valov
- JARA - Fundamentals for Future Information Technology, 52425, Jülich, Germany
- Peter-Grünberg-Institut (PGI 7), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425, Jülich, Germany
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10
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Raeis-Hosseini N, Chen S, Papavassiliou C, Valov I. Impact of Zr top electrode on tantalum oxide-based electrochemical metallization resistive switching memory: towards synaptic functionalities. RSC Adv 2022; 12:14235-14245. [PMID: 35558855 PMCID: PMC9092617 DOI: 10.1039/d2ra02456j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 05/05/2022] [Indexed: 11/21/2022] Open
Abstract
Electrochemical metallization memory (ECM) devices have been made by sub-stoichiometric deposition of a tantalum oxide switching film (Ta2O5-x ) using sputtering. We investigated the influence of zirconium as the active top electrode material in the lithographically fabricated ECM devices. A simple capacitor like (Pt/Zr/Ta2O5-x /Pt) structure represented the resistive switching memory. A cyclic voltammetry measurement demonstrated the electrochemical process of the memory device. The I-V characteristics of ECMs show stable bipolar resistive switching properties with reliable endurance and retention. The resistive switching mechanism results from the formation and rupture of a conductive filament characteristic of ECM. Our results suggest that Zr can be considered a potential active electrode in the ECMs for the next generation of nonvolatile nanoelectronics. We successfully showed that the ECM device can work under AC pulses to emulate the essential characteristics of an artificial synapse by further improvements.
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Affiliation(s)
- Niloufar Raeis-Hosseini
- Department of Electronics and Electrical Engineering, Imperial College London London SW7 2BT UK
| | - Shaochuan Chen
- Peter Gruenberg Institute, Research Centre Juelich Juelich 52425 Germany
| | - Christos Papavassiliou
- Department of Electronics and Electrical Engineering, Imperial College London London SW7 2BT UK
| | - Ilia Valov
- Peter Gruenberg Institute, Research Centre Juelich Juelich 52425 Germany.,Institute for Materials in Electrical Engineering II, RWTH Aachen University Sommerfeldstrasse 24 Aachen 52074 Germany
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11
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Chen S, Valov I. Design of Materials Configuration for Optimizing Redox-Based Resistive Switching Memories. Adv Mater 2022; 34:e2105022. [PMID: 34695257 DOI: 10.1002/adma.202105022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/19/2021] [Indexed: 06/13/2023]
Abstract
Redox-based resistive random access memories (ReRAMs) are based on electrochemical processes of oxidation and reduction within the devices. The selection of materials and material combinations strongly influence the related nanoscale processes, playing a crucial role in resistive switching properties and functionalities. To date, however, comprehensive studies on device design accounting for a combination of factors such as electrodes, electrolytes, and capping layer materials related to their thicknesses and interactions are scarce. In this work, the impact of materials' configuration on interfacial redox reactions in HfO2 -based electrochemical metallization memory (ECM) and valence-change memory (VCM) systems is reported. The redox processes are studied by cyclic voltammetry, and the corresponding resistive switching characteristics are investigated. In ECM cells, the overall cell resistance depends on the electrocatalytic activity of the counter electrode. Nonetheless, the capping layer material further influences the cell resistance and the SET and RESET voltages. In VCM systems, the influence of the electrode material configuration is also pronounced, and is capable of modulating the active resistive switching interface. For both types of memory cells, the switching behavior changes significantly with variation of the oxide thickness. The results present important materials selection criteria for rationale design of ReRAM cells for various memristive applications.
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Affiliation(s)
- Shaochuan Chen
- Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, Sommerfeldstraße 24, 52074, Aachen, Germany
| | - Ilia Valov
- Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, Sommerfeldstraße 24, 52074, Aachen, Germany
- Peter Grünberg Institut 7 and JARA-FIT, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425, Jülich, Germany
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12
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Lanza M, Waser R, Ielmini D, Yang JJ, Goux L, Suñe J, Kenyon AJ, Mehonic A, Spiga S, Rana V, Wiefels S, Menzel S, Valov I, Villena MA, Miranda E, Jing X, Campabadal F, Gonzalez MB, Aguirre F, Palumbo F, Zhu K, Roldan JB, Puglisi FM, Larcher L, Hou TH, Prodromakis T, Yang Y, Huang P, Wan T, Chai Y, Pey KL, Raghavan N, Dueñas S, Wang T, Xia Q, Pazos S. Standards for the Characterization of Endurance in Resistive Switching Devices. ACS Nano 2021; 15:17214-17231. [PMID: 34730935 DOI: 10.1021/acsnano.1c06980] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Resistive switching (RS) devices are emerging electronic components that could have applications in multiple types of integrated circuits, including electronic memories, true random number generators, radiofrequency switches, neuromorphic vision sensors, and artificial neural networks. The main factor hindering the massive employment of RS devices in commercial circuits is related to variability and reliability issues, which are usually evaluated through switching endurance tests. However, we note that most studies that claimed high endurances >106 cycles were based on resistance versus cycle plots that contain very few data points (in many cases even <20), and which are collected in only one device. We recommend not to use such a characterization method because it is highly inaccurate and unreliable (i.e., it cannot reliably demonstrate that the device effectively switches in every cycle and it ignores cycle-to-cycle and device-to-device variability). This has created a blurry vision of the real performance of RS devices and in many cases has exaggerated their potential. This article proposes and describes a method for the correct characterization of switching endurance in RS devices; this method aims to construct endurance plots showing one data point per cycle and resistive state and combine data from multiple devices. Adopting this recommended method should result in more reliable literature in the field of RS technologies, which should accelerate their integration in commercial products.
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Affiliation(s)
- Mario Lanza
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Rainer Waser
- Peter-Grünberg-Institut (PGI-7), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- Peter-Grünberg-Institut (PGI-10), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- Institut für Werkstoffe der Elektrotechnik 2 (IWE2), RWTH Aachen University, Aachen 52074, Germany
| | - Daniele Ielmini
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano and IU.NET, Piazza L. da Vinci 32, Milano, 20133, Italy
| | - J Joshua Yang
- Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, California 90089, United States
| | | | - Jordi Suñe
- Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona, Barcelona 08193, Spain
| | - Anthony Joseph Kenyon
- Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom
| | - Adnan Mehonic
- Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom
| | - Sabina Spiga
- CNR-IMM, Unit of Agrate Brianza, Via C. Olivetti 2, Agrate Brianza (MB) 20864, Italy
| | - Vikas Rana
- Peter-Grünberg-Institut (PGI-10), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Stefan Wiefels
- Peter-Grünberg-Institut (PGI-7), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Stephan Menzel
- Peter-Grünberg-Institut (PGI-7), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Ilia Valov
- Peter-Grünberg-Institut (PGI-7), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Marco A Villena
- Applied Materials Inc., Via Ruini, Reggio Emilia 74L 42122, Italy
| | - Enrique Miranda
- Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona, Barcelona 08193, Spain
| | - Xu Jing
- School of Materials Science and Engineering, Jiangsu Key Laboratory of Advanced Metallic Materials, Southeast University, Nanjing 211189, China
| | - Francesca Campabadal
- Institut de Microelectrònica de Barcelona-Centre Nacional de Microelectrònica, Consejo Superior de Investigaciones Científicas, Bellaterra 08193, Spain
| | - Mireia B Gonzalez
- Institut de Microelectrònica de Barcelona-Centre Nacional de Microelectrònica, Consejo Superior de Investigaciones Científicas, Bellaterra 08193, Spain
| | - Fernando Aguirre
- Unidad de Investigación y Desarrollo de las Ingenierías-CONICET, Facultad Regional Buenos Aires, Universidad Tecnológica Nacional (UIDI-CONICET/FRBA-UTN), Buenos Aires, Medrano 951(C1179AAQ), Argentina
| | - Felix Palumbo
- Unidad de Investigación y Desarrollo de las Ingenierías-CONICET, Facultad Regional Buenos Aires, Universidad Tecnológica Nacional (UIDI-CONICET/FRBA-UTN), Buenos Aires, Medrano 951(C1179AAQ), Argentina
| | - Kaichen Zhu
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Juan Bautista Roldan
- Departamento de Electrónica y Tecnología de Computadores, Facultad de Ciencias, Universidad de Granada, Avd. Fuentenueva s/n, Granada 18071, Spain
| | - Francesco Maria Puglisi
- Dipartimento di Ingegneria "Enzo Ferrari", Università di Modena e Reggio Emilia, Via P. Vivarelli 10/1, Modena 41125, Italy
| | - Luca Larcher
- Applied Materials Inc., Via Ruini, Reggio Emilia 74L 42122, Italy
| | - Tuo-Hung Hou
- Department of Electronics Engineering and Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Themis Prodromakis
- Centre for Electronics Frontiers, University of Southampton, Southampton SO171BJ, United Kingdom
| | - Yuchao Yang
- Key Laboratory of Microelectronic Devices and Circuits (MOE), Department of Micro/nanoelectronics, Peking University, Beijing 100871, China
| | - Peng Huang
- Key Laboratory of Microelectronic Devices and Circuits (MOE), Department of Micro/nanoelectronics, Peking University, Beijing 100871, China
| | - Tianqing Wan
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Yang Chai
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Kin Leong Pey
- Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, 487372 Singapore
| | - Nagarajan Raghavan
- Engineering Product Development, Singapore University of Technology and Design (SUTD), 8 Somapah Road, 487372 Singapore
| | - Salvador Dueñas
- Department of Electronics, University of Valladolid, Paseo de Belén 15, Valladolid E-47011, Spain
| | - Tao Wang
- Institute of Functional Nano and Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University 199 Ren-Ai Road, Suzhou 215123, China
| | - Qiangfei Xia
- Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, Massachusetts 01003-9292, United States
| | - Sebastian Pazos
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
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13
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Tappertzhofen S, Nielen L, Valov I, Waser R. Memristively programmable transistors. Nanotechnology 2021; 33:045203. [PMID: 34670198 DOI: 10.1088/1361-6528/ac317f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 10/20/2021] [Indexed: 06/13/2023]
Abstract
When designing the gate-dielectric of a floating-gate-transistor, one must make a tradeoff between the necessity of providing an ultra-small leakage current behavior for long state retention, and a moderate to high tunneling-rate for fast programming speed. Here we report on a memristively programmable transistor that overcomes this tradeoff. The operation principle is comparable to floating-gate-transistors, but the advantage of the analyzed concept is that ions instead of electrons are used for programming. Since the mass of ions is significantly larger than the effective mass of electrons, gate-dielectrics with higher leakage current levels can be used. We demonstrate the practical feasibility of the device using a proof-of-concept study based on a micrometer-sized thin-film transistor and LT-Spice simulations of 32 nm transistors. Memristively programmable transistors have the potential of high programming endurance and retention times, fast programming speeds, and high scalability.
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Affiliation(s)
- S Tappertzhofen
- Chair for Micro- and Nanoelectronics, Department of Electrical Engineering and Information Technology, TU Dortmund University, Emil-Figge-Straße 68, D-44227, Dortmund, Germany
| | - L Nielen
- aixACCT Systems GmbH, Talbotstraße 25, D-52068 Aachen, Germany
| | - I Valov
- Institute for Electronic Materials (IWE 2) RWTH Aachen University, Sommerfeld Straße 24, D-52074 Aachen, Germany
- Jülich Research Center, Peter-Grünberg-Institute 7 (PGI 7), Wilhelm-Johnen-Straße 1, D-52428 Jülich, Germany
| | - R Waser
- Institute for Electronic Materials (IWE 2) RWTH Aachen University, Sommerfeld Straße 24, D-52074 Aachen, Germany
- Jülich Research Center, Peter-Grünberg-Institute 7 (PGI 7), Wilhelm-Johnen-Straße 1, D-52428 Jülich, Germany
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14
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Milano G, Raffone F, Luebben M, Boarino L, Cicero G, Valov I, Ricciardi C. Water-Mediated Ionic Migration in Memristive Nanowires with a Tunable Resistive Switching Mechanism. ACS Appl Mater Interfaces 2020; 12:48773-48780. [PMID: 33052645 PMCID: PMC8014891 DOI: 10.1021/acsami.0c13020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 10/02/2020] [Indexed: 06/11/2023]
Abstract
Memristive devices based on electrochemical resistive switching effects have been proposed as promising candidates for in-memory computing and for the realization of artificial neural networks. Despite great efforts toward understanding the nanoionic processes underlying resistive switching phenomena, comprehension of the effect of competing redox processes on device functionalities from the materials perspective still represents a challenge. In this work, we experimentally and theoretically investigate the concurring reactions of silver and moisture and their impact on the electronic properties of a single-crystalline ZnO nanowire (NW). A decrease in electronic conductivity due to surface adsorption of moisture is observed, whereas, at the same time, water molecules reduce the energy barrier for Ag+ ion migration on the NW surface, facilitating the conductive filament formation. By controlling the relative humidity, the ratio of intrinsic electronic conductivity and surface ionic conductivity can be tuned to modulate the device performance. The results achieved on a single-crystalline memristive model system shed new light on the dual nature of the mechanism of how moisture affects resistive switching behavior in memristive devices.
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Affiliation(s)
- Gianluca Milano
- Department
of Applied Science and Technology, Politecnico
di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
- Advanced
Materials Metrology and Life Science Division, INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, 10135 Torino, Italy
| | - Federico Raffone
- Department
of Applied Science and Technology, Politecnico
di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Michael Luebben
- Institute
for Materials in Electrical Engineering II, RWTH Aachen University, Sommerfeldstrasse 24, 52074 Aachen, Germany
- JARA—Fundamentals
for Future Information Technology, 52425 Jülich, Germany
| | - Luca Boarino
- Advanced
Materials Metrology and Life Science Division, INRiM (Istituto Nazionale di Ricerca Metrologica), Strada delle Cacce 91, 10135 Torino, Italy
| | - Giancarlo Cicero
- Department
of Applied Science and Technology, Politecnico
di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Ilia Valov
- JARA—Fundamentals
for Future Information Technology, 52425 Jülich, Germany
- Peter-Grünberg-Institut
(PGI 7), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | - Carlo Ricciardi
- Department
of Applied Science and Technology, Politecnico
di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
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15
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Affiliation(s)
- Ilia Valov
- Electronic Materials (PGI-7), Research Centre Juelich, Juelich, Germany.
| | - Yuchao Yang
- Key Laboratory of Microelectronic Devices and Circuits (MOE), Department of Micro/nanoelectronics, Peking University, Beijing, China.
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16
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Lübben M, Cüppers F, Mohr J, von Witzleben M, Breuer U, Waser R, Neumann C, Valov I. Design of defect-chemical properties and device performance in memristive systems. Sci Adv 2020; 6:eaaz9079. [PMID: 32548248 PMCID: PMC7272230 DOI: 10.1126/sciadv.aaz9079] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 02/24/2020] [Indexed: 05/24/2023]
Abstract
Future development of the modern nanoelectronics and its flagships internet of things, artificial intelligence, and neuromorphic computing is largely associated with memristive elements, offering a spectrum of inevitable functionalities, atomic level scalability, and low-power operation. However, their development is limited by significant variability and still phenomenologically orientated materials' design strategy. Here, we highlight the vital importance of materials' purity, demonstrating that even parts-per-million foreign elements substantially change performance. Appropriate choice of chemistry and amount of doping element selectively enhances the desired functionality. Dopant/impurity-dependent structure and charge/potential distribution in the space-charge layers and cell capacitance determine the device kinetics and functions. The relation between chemical composition/purity and switching/neuromorphic performance is experimentally evidenced, providing directions for a rational design of future memristive devices.
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Affiliation(s)
- M. Lübben
- Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, Sommerfeldstraße 24, 52074 Aachen, Germany
- JARA–Fundamentals for Future Information Technology, 52425 Jülich, Germany
| | - F. Cüppers
- Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, Sommerfeldstraße 24, 52074 Aachen, Germany
- JARA–Fundamentals for Future Information Technology, 52425 Jülich, Germany
| | - J. Mohr
- Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, Sommerfeldstraße 24, 52074 Aachen, Germany
- JARA–Fundamentals for Future Information Technology, 52425 Jülich, Germany
| | - M. von Witzleben
- Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, Sommerfeldstraße 24, 52074 Aachen, Germany
- JARA–Fundamentals for Future Information Technology, 52425 Jülich, Germany
| | - U. Breuer
- Central Institute for Engineering, Electronics and Analytics, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - R. Waser
- Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, Sommerfeldstraße 24, 52074 Aachen, Germany
- JARA–Fundamentals for Future Information Technology, 52425 Jülich, Germany
- Peter-Grünberg-Institut (PGI 7), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | - C. Neumann
- Heraeus Deutschland GmbH & Co. KG Heraeusstrasse 12-14, 63450 Hanau, Germany
| | - I. Valov
- JARA–Fundamentals for Future Information Technology, 52425 Jülich, Germany
- Peter-Grünberg-Institut (PGI 7), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany
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17
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Singh A, Schneller T, Valov I, Singh I, Srivastava A, Waser R. Copper facilitated nickel oxy-hydroxide films as efficient synergistic oxygen evolution electrocatalyst. J Catal 2020. [DOI: 10.1016/j.jcat.2020.02.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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Aono M, Baeumer C, Bartlett P, Brivio S, Burr G, Burriel M, Carlos E, Deswal S, Deuermeier J, Dittmann R, Du H, Gale E, Hambsch S, Hilgenkamp H, Ielmini D, Kenyon AJ, Kiazadeh A, Kindsmüller A, Kissling G, Köymen I, Menzel S, Pla Asesio D, Prodromakis T, Santamaria M, Shluger A, Thompson D, Valov I, Wang W, Waser R, Williams RS, Wrana D, Wouters D, Yang Y, Zaffora A. Valence change ReRAMs (VCM) - Experiments and modelling: general discussion. Faraday Discuss 2019; 213:259-286. [PMID: 30664143 DOI: 10.1039/c8fd90057d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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19
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Hiraya W, Mishima N, Shima T, Tai S, Tsuruoka T, Valov I, Hasegawa T. Resistivity control by the electrochemical removal of dopant atoms from a nanodot. Faraday Discuss 2019; 213:29-40. [PMID: 30357246 DOI: 10.1039/c8fd00099a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Doping impurity atoms into semiconductor materials changes the resistance of the material. Selecting the atomic species of a dopant and the precise control of the number of dopant atoms in a unit volume can control the resistance to a desired value. The number of dopant atoms is usually controlled when the materials are synthesized. It can also be controlled after synthesizing by injecting dopant atoms using an ion implantation technique. This physical method has now enabled atom by atom implantation at the desired position. Here, we propose an additional technique, based on the electrochemical potential of dopant atoms in a material. The technique enables the dynamic control of the number of dopant atoms through the application of bias to the material. We demonstrate the controlled removal of dopant atoms using Ag2+δS and Ag-doped Ta2O5 as model materials. The change in resistance accompanying the removal of dopant atoms is also observed.
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Affiliation(s)
- Wataru Hiraya
- Graduate School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
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Bartlett P, Berg AI, Bernasconi M, Brown S, Burr G, Foroutan-Nejad C, Gale E, Huang R, Ielmini D, Kissling G, Kolosov V, Kozicki M, Nakamura H, Rushchanskii K, Salinga M, Shluger A, Thompson D, Valov I, Wang W, Waser R, Williams RS. Phase-change memories (PCM) - Experiments and modelling: general discussion. Faraday Discuss 2019; 213:393-420. [PMID: 30697618 DOI: 10.1039/c8fd90064g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Abstract
Redox-based resistive switching memories (ReRAMs) are the strongest candidates for next generation nonvolatile memories. These devices are commonly composed of metal/solid electrolyte/metal junctions, where the solid electrolyte is usually an oxide layer. A key aspect in the ReRAMs development is the solid electrolyte engineering, since it is crucial to tailor the material properties for obtaining excellent switching properties (e.g. retention, endurance, etc.). Here we present an anodizing process as a non vacuum and low temperature electrochemical technique for growing oxides with tailored structural and electronic properties. The effect of the anodizing conditions on the solid state properties of the anodic oxides is studied in relation to the final ReRAM device performances demonstrating the great potentiality of this technique to produce high quality oxide thin films for resistive switching memories.
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Affiliation(s)
- A Zaffora
- Electrochemical Materials Science Laboratory, DICAM, Università degli Studi di Palermo, Viale delle Scienze, Ed. 6, Palermo 90128, Italy.
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22
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Ambrosi E, Bartlett P, Berg AI, Brivio S, Burr G, Deswal S, Deuermeier J, Haga MA, Kiazadeh A, Kissling G, Kozicki M, Foroutan-Nejad C, Gale E, Gonzalez-Velo Y, Goossens A, Goux L, Hasegawa T, Hilgenkamp H, Huang R, Ibrahim S, Ielmini D, Kenyon AJ, Kolosov V, Li Y, Majumdar S, Milano G, Prodromakis T, Raeishosseini N, Rana V, Ricciardi C, Santamaria M, Shluger A, Valov I, Waser R, Williams RS, Wouters D, Yang Y, Zaffora A. Electrochemical metallization ReRAMs (ECM) - Experiments and modelling: general discussion. Faraday Discuss 2019; 213:115-150. [PMID: 30663725 DOI: 10.1039/c8fd90059k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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Abstract
Ilia Valov and Philip Bartlett introduce the Faraday Discussion volume on New memory paradigms: memristive phenomena and neuromorphic applications.
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Affiliation(s)
- Ilia Valov
- Peter Grünberg Institut, Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany.
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24
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Berg AI, Brivio S, Brown S, Burr G, Deswal S, Deuermeier J, Gale E, Hwang H, Ielmini D, Indiveri G, Kenyon AJ, Kiazadeh A, Köymen I, Kozicki M, Li Y, Mannion D, Prodromakis T, Ricciardi C, Siegel S, Speckbacher M, Valov I, Wang W, Williams RS, Wouters D, Yang Y. Synaptic and neuromorphic functions: general discussion. Faraday Discuss 2019; 213:553-578. [PMID: 30697617 DOI: 10.1039/c8fd90065e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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25
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Mehonic A, Shluger AL, Gao D, Valov I, Miranda E, Ielmini D, Bricalli A, Ambrosi E, Li C, Yang JJ, Xia Q, Kenyon AJ. Silicon Oxide (SiO x ): A Promising Material for Resistance Switching? Adv Mater 2018; 30:e1801187. [PMID: 29957849 DOI: 10.1002/adma.201801187] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 04/30/2018] [Indexed: 06/08/2023]
Abstract
Interest in resistance switching is currently growing apace. The promise of novel high-density, low-power, high-speed nonvolatile memory devices is appealing enough, but beyond that there are exciting future possibilities for applications in hardware acceleration for machine learning and artificial intelligence, and for neuromorphic computing. A very wide range of material systems exhibit resistance switching, a number of which-primarily transition metal oxides-are currently being investigated as complementary metal-oxide-semiconductor (CMOS)-compatible technologies. Here, the case is made for silicon oxide, perhaps the most CMOS-compatible dielectric, yet one that has had comparatively little attention as a resistance-switching material. Herein, a taxonomy of switching mechanisms in silicon oxide is presented, and the current state of the art in modeling, understanding fundamental switching mechanisms, and exciting device applications is summarized. In conclusion, silicon oxide is an excellent choice for resistance-switching technologies, offering a number of compelling advantages over competing material systems.
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Affiliation(s)
- Adnan Mehonic
- Department of Electronic and Electrical Engineering, UCL, Torrington Place, London, WC1E 7JE, UK
| | - Alexander L Shluger
- Department of Physics and Astronomy, UCL, Gower Street, London, WC1E 6BT, UK
| | - David Gao
- Department of Physics and Astronomy, UCL, Gower Street, London, WC1E 6BT, UK
| | - Ilia Valov
- Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, 52074, Aachen, Germany
| | - Enrique Miranda
- Departament d'Enginyeria Electronica, Universitat Autonoma de Barcelona, 08193, Bellaterra, Spain
| | - Daniele Ielmini
- Dipartimento di Elettronica e Informazione, Politecnico di Milano, Milan, 20133, Italy
| | - Alessandro Bricalli
- Dipartimento di Elettronica e Informazione, Politecnico di Milano, Milan, 20133, Italy
| | - Elia Ambrosi
- Dipartimento di Elettronica e Informazione, Politecnico di Milano, Milan, 20133, Italy
| | - Can Li
- Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, MA, 01003, USA
| | - J Joshua Yang
- Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, MA, 01003, USA
| | - Qiangfei Xia
- Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, MA, 01003, USA
| | - Anthony J Kenyon
- Department of Electronic and Electrical Engineering, UCL, Torrington Place, London, WC1E 7JE, UK
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26
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Zhang Q, Shi Z, Yin K, Dong H, Xu F, Peng X, Yu K, Zhang H, Chen CC, Valov I, Zheng H, Sun L. Spring-Like Pseudoelectroelasticity of Monocrystalline Cu 2S Nanowire. Nano Lett 2018; 18:5070-5077. [PMID: 29965777 DOI: 10.1021/acs.nanolett.8b01914] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Prediction from the dual-phase nature of superionic conductors-both solid and liquid-like-is that mobile ions in the material may experience reversible extraction-reinsertion by an external electric field. However, this type of pseudoelectroelasticity has not been confirmed in situ, and no details on the microscopic mechanism are known. Here, we in situ monitor the pseudoelectroelasticity of monocrystalline Cu2S nanowires (NWs) using transmission electron microscopy (TEM). Specifically, we reveal the atomic scale details including phase transformation, migration and redox reactions of Cu+ ions, nucleation, growth, as well as spontaneous shrinking of Cu protrusion. Caterpillar-diffusion-dominated deformation is confirmed by the high-resolution transmission electron microscopy (HRTEM) observation and ab initio calculation, which can be driven by either an external electric field or chemical potential difference. The observed spring-like behavior was creatively adopted for electric nanoactuators. Our findings are crucial to elucidate the mechanism of pseudoelectroelasticity and could potentially stimulate in-depth research into electrochemical and nanoelectromechanical systems.
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Affiliation(s)
- Qiubo Zhang
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System , Southeast University , Nanjing 210018 , P. R. China
- Materials Science Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Zhe Shi
- Department of Materials Science and Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Kuibo Yin
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System , Southeast University , Nanjing 210018 , P. R. China
| | - Hui Dong
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System , Southeast University , Nanjing 210018 , P. R. China
| | - Feng Xu
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System , Southeast University , Nanjing 210018 , P. R. China
| | - Xinxing Peng
- Materials Science Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Kaihao Yu
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System , Southeast University , Nanjing 210018 , P. R. China
| | - Hongtao Zhang
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System , Southeast University , Nanjing 210018 , P. R. China
| | - Chia-Chin Chen
- Max Planck Institute for Solid State Research , Heisenbergstrasse 1 , 70569 Stuttgart Germany
| | - Ilia Valov
- Peter Gruenberg Institute, Electronic Materials , Research Centre Juelich , 52425 Juelich , Germany
| | - Haimei Zheng
- Materials Science Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Department of Materials Science and Engineering , University of California , Berkeley , California 94720 , United States
| | - Litao Sun
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Collaborative Innovation Center for Micro/Nano Fabrication, Device and System , Southeast University , Nanjing 210018 , P. R. China
- Center for Advanced Materials and Manufacture , Joint Research Institute of Southeast University and Monash University , Suzhou 215123 , P. R. China
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27
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Heisig T, Baeumer C, Gries UN, Mueller MP, La Torre C, Luebben M, Raab N, Du H, Menzel S, Mueller DN, Jia CL, Mayer J, Waser R, Valov I, De Souza RA, Dittmann R. Oxygen Exchange Processes between Oxide Memristive Devices and Water Molecules. Adv Mater 2018; 30:e1800957. [PMID: 29882270 DOI: 10.1002/adma.201800957] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 04/18/2018] [Indexed: 06/08/2023]
Abstract
Resistive switching based on transition metal oxide memristive devices is suspected to be caused by the electric-field-driven motion and internal redistribution of oxygen vacancies. Deriving the detailed mechanistic picture of the switching process is complicated, however, by the frequently observed influence of the surrounding atmosphere. Specifically, the presence or absence of water vapor in the atmosphere has a strong impact on the switching properties, but the redox reactions between water and the active layer have yet to be clarified. To investigate the role of oxygen and water species during resistive switching in greater detail, isotope labeling experiments in a N2 /H218 O tracer gas atmosphere combined with time-of-flight secondary-ion mass spectrometry are used. It is explicitly demonstrated that during the RESET operation in resistive switching SrTiO3 -based memristive devices, oxygen is incorporated directly from water molecules or oxygen molecules into the active layer. In humid atmospheres, the reaction pathway via water molecules predominates. These findings clearly resolve the role of humidity as both oxidizing agent and source of protonic defects during the RESET operation.
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Affiliation(s)
- Thomas Heisig
- Peter Gruenberg Institute, Forschungszentrum Juelich GmbH and JARA-FIT, 52425, Juelich, Germany
| | - Christoph Baeumer
- Peter Gruenberg Institute, Forschungszentrum Juelich GmbH and JARA-FIT, 52425, Juelich, Germany
| | - Ute N Gries
- Institute of Physical Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Michael P Mueller
- Institute of Physical Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Camilla La Torre
- Institute of Electronic Materials, IWE2, RWTH Aachen University, 52056, Aachen, Germany
| | - Michael Luebben
- Institute of Electronic Materials, IWE2, RWTH Aachen University, 52056, Aachen, Germany
| | - Nicolas Raab
- Peter Gruenberg Institute, Forschungszentrum Juelich GmbH and JARA-FIT, 52425, Juelich, Germany
| | - Hongchu Du
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Juelich GmbH and RWTH Aachen University, 52425, Juelich, Germany
| | - Stephan Menzel
- Peter Gruenberg Institute, Forschungszentrum Juelich GmbH and JARA-FIT, 52425, Juelich, Germany
| | - David N Mueller
- Peter Gruenberg Institute, Forschungszentrum Juelich GmbH and JARA-FIT, 52425, Juelich, Germany
| | - Chun-Lin Jia
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Juelich GmbH and RWTH Aachen University, 52425, Juelich, Germany
| | - Joachim Mayer
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Juelich GmbH and RWTH Aachen University, 52425, Juelich, Germany
| | - Rainer Waser
- Peter Gruenberg Institute, Forschungszentrum Juelich GmbH and JARA-FIT, 52425, Juelich, Germany
- Institute of Electronic Materials, IWE2, RWTH Aachen University, 52056, Aachen, Germany
| | - Ilia Valov
- Peter Gruenberg Institute, Forschungszentrum Juelich GmbH and JARA-FIT, 52425, Juelich, Germany
| | - Roger A De Souza
- Institute of Physical Chemistry, RWTH Aachen University, 52056, Aachen, Germany
| | - Regina Dittmann
- Peter Gruenberg Institute, Forschungszentrum Juelich GmbH and JARA-FIT, 52425, Juelich, Germany
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28
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29
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Nayak A, Unayama S, Tai S, Tsuruoka T, Waser R, Aono M, Valov I, Hasegawa T. Nanoarchitectonics for Controlling the Number of Dopant Atoms in Solid Electrolyte Nanodots. Adv Mater 2018; 30. [PMID: 29314325 DOI: 10.1002/adma.201703261] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 10/01/2017] [Indexed: 05/15/2023]
Abstract
Controlling movements of electrons and holes is the key task in developing today's highly sophisticated information society. As transistors reach their physical limits, the semiconductor industry is seeking the next alternative to sustain its economy and to unfold a new era of human civilization. In this context, a completely new information token, i.e., ions instead of electrons, is promising. The current trend in solid-state nanoionics for applications in energy storage, sensing, and brain-type information processing, requires the ability to control the properties of matter at the ultimate atomic scale. Here, a conceptually novel nanoarchitectonic strategy is proposed for controlling the number of dopant atoms in a solid electrolyte to obtain discrete electrical properties. Using α-Ag2+δ S nanodots with a finite number of nonstoichiometry excess dopants as a model system, a theory matched with experiments is presented that reveals the role of physical parameters, namely, the separation between electrochemical energy levels and the cohesive energy, underlying atomic-scale manipulation of dopants in nanodots. This strategy can be applied to different nanoscale materials as their properties strongly depend on the number of doping atoms/ions, and has the potential to create a new paradigm based on controlled single atom/ion transfer.
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Affiliation(s)
- Alpana Nayak
- WPI Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Satomi Unayama
- WPI Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Seishiro Tai
- Faculty of Science, and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan
| | - Tohru Tsuruoka
- WPI Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Rainer Waser
- Research Centre Juelich, Peter Gruenberg Institute, Electronic Materials, 52425, Juelich, Germany
- IWE2 & JARA-FIT, RWTH Aachen University, 52056, Aachen, Germany
| | - Masakazu Aono
- WPI Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Ilia Valov
- Research Centre Juelich, Peter Gruenberg Institute, Electronic Materials, 52425, Juelich, Germany
- IWE2 & JARA-FIT, RWTH Aachen University, 52056, Aachen, Germany
| | - Tsuyoshi Hasegawa
- Faculty of Science, and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan
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30
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Bick DS, Krebs TB, Kleimaier D, Zurhelle AF, Staikov G, Waser R, Valov I. Degradation Kinetics during Oxygen Electrocatalysis on Perovskite-Based Surfaces in Alkaline Media. Langmuir 2018; 34:1347-1352. [PMID: 29303591 DOI: 10.1021/acs.langmuir.7b03733] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The oxygen evolution reaction (OER) during alkaline water electrolysis is the bottleneck of water splitting. Perovskite materials have been particularly proposed as good and economically reasonable electrocatalysts for the OER, showing promise and advantages with respect to classic metallic electrodes. However, the degradation of perovskites during catalysis limits their service lifetime. Recently, the material BaCo0.98Ti0.02O3-δ:Co3O4 was shown to be electrocatalytically and chemically stable during water electrolysis even under industrially relevant conditions. The lifetime of this perovskite-based system is prolonged by a factor of 10 in comparison to that of Pr0.2Ba0.8CoO3-δ and is comparable to that of industrially applied electrodes. Here we report on the degradation kinetics of several OER catalysts at room temperature, comparatively studied by monitoring the oxygen evolution at microelectrodes. A decrease in the reaction rate within a maximum of 60 s is observed, which is related to chemical and/or structural changes at the oxide surface.
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Affiliation(s)
- D S Bick
- Institute for Materials in Electrical Engineering and Information Technology (IWE2), RWTH Aachen University of Technology , D-52074 Aachen, Germany
| | - T B Krebs
- Institute for Materials in Electrical Engineering and Information Technology (IWE2), RWTH Aachen University of Technology , D-52074 Aachen, Germany
| | - D Kleimaier
- Institute for Materials in Electrical Engineering and Information Technology (IWE2), RWTH Aachen University of Technology , D-52074 Aachen, Germany
| | - A F Zurhelle
- Institute for Materials in Electrical Engineering and Information Technology (IWE2), RWTH Aachen University of Technology , D-52074 Aachen, Germany
| | - G Staikov
- Institute for Materials in Electrical Engineering and Information Technology (IWE2), RWTH Aachen University of Technology , D-52074 Aachen, Germany
| | - R Waser
- Institute for Materials in Electrical Engineering and Information Technology (IWE2), RWTH Aachen University of Technology , D-52074 Aachen, Germany
| | - I Valov
- Institute for Materials in Electrical Engineering and Information Technology (IWE2), RWTH Aachen University of Technology , D-52074 Aachen, Germany
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31
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Stathopoulos S, Khiat A, Trapatseli M, Cortese S, Serb A, Valov I, Prodromakis T. Multibit memory operation of metal-oxide bi-layer memristors. Sci Rep 2017; 7:17532. [PMID: 29235524 PMCID: PMC5727485 DOI: 10.1038/s41598-017-17785-1] [Citation(s) in RCA: 171] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/30/2017] [Indexed: 11/13/2022] Open
Abstract
Emerging nanoionic memristive devices are considered as the memory technology of the future and have been winning a great deal of attention due to their ability to perform fast and at the expense of low-power and -space requirements. Their full potential is envisioned that can be fulfilled through their capacity to store multiple memory states per cell, which however has been constrained so far by issues affecting the long-term stability of independent states. Here, we introduce and evaluate a multitude of metal-oxide bi-layers and demonstrate the benefits from increased memory stability via multibit memory operation. We propose a programming methodology that allows for operating metal-oxide memristive devices as multibit memory elements with highly packed yet clearly discernible memory states. These states were found to correlate with the transport properties of the introduced barrier layers. We are demonstrating memory cells with up to 6.5 bits of information storage as well as excellent retention and power consumption performance. This paves the way for neuromorphic and non-volatile memory applications.
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Affiliation(s)
- Spyros Stathopoulos
- Department of Electronics and Computer Science, Faculty of Physical Science and Engineering, University of Southampton, University Road, SO17 1BJ, Southampton, United Kingdom
| | - Ali Khiat
- Department of Electronics and Computer Science, Faculty of Physical Science and Engineering, University of Southampton, University Road, SO17 1BJ, Southampton, United Kingdom
| | - Maria Trapatseli
- Department of Electronics and Computer Science, Faculty of Physical Science and Engineering, University of Southampton, University Road, SO17 1BJ, Southampton, United Kingdom
| | - Simone Cortese
- Department of Electronics and Computer Science, Faculty of Physical Science and Engineering, University of Southampton, University Road, SO17 1BJ, Southampton, United Kingdom
| | - Alexantrou Serb
- Department of Electronics and Computer Science, Faculty of Physical Science and Engineering, University of Southampton, University Road, SO17 1BJ, Southampton, United Kingdom
| | - Ilia Valov
- Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52428, Jülich, Germany
| | - Themis Prodromakis
- Department of Electronics and Computer Science, Faculty of Physical Science and Engineering, University of Southampton, University Road, SO17 1BJ, Southampton, United Kingdom.
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32
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Affiliation(s)
- Ilia Valov
- Research Centre Jülich, Electronic Materials (PGI-7), Wilhelm-Johnen- Straße, 52425 Jülich, Germany
| | - Michael Kozicki
- School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287-5706, USA
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33
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Zaffora A, Cho DY, Lee KS, Di Quarto F, Waser R, Santamaria M, Valov I. Electrochemical Tantalum Oxide for Resistive Switching Memories. Adv Mater 2017; 29:1703357. [PMID: 28984996 DOI: 10.1002/adma.201703357] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 08/18/2017] [Indexed: 06/07/2023]
Abstract
Redox-based resistive switching memories (ReRAMs) are strongest candidates for the next-generation nonvolatile memories fulfilling the criteria for fast, energy efficient, and scalable green IT. These types of devices can also be used for selector elements, alternative logic circuits and computing, and memristive and neuromorphic operations. ReRAMs are composed of metal/solid electrolyte/metal junctions in which the solid electrolyte is typically a metal oxide or multilayer oxides structures. Here, this study offers an effective and cheap electrochemical approach to fabricate Ta/Ta2 O5 -based devices by anodizing. This method allows to grow high-quality and dense oxide thin films onto a metallic substrates with precise control over morphology and thickness. Electrochemical-oxide-based devices demonstrate superior properties, i.e., endurance of at least 106 pulse cycles and/or 103 I-V sweeps maintaining a good memory window with a low dispersion in ROFF and RON values, nanosecond fast switching, and data retention of at least 104 s. Multilevel programing capability is presented with both I-V sweeps and pulse measurements. Thus, it is shown that anodizing has a great prospective as a method for preparation of dense oxide films for resistive switching memories.
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Affiliation(s)
- Andrea Zaffora
- Electrochemical Materials Science Laboratory, DICAM, Palermo University, Palermo, 90128, Italy
| | - Deok-Yong Cho
- IPIT and Department of Physics, Chonbuk National University, Jeonju, 54896, South Korea
| | - Kug-Seung Lee
- Pohang Accelerator Laboratory, Pohang, 37673, South Korea
| | - Francesco Di Quarto
- Electrochemical Materials Science Laboratory, DICAM, Palermo University, Palermo, 90128, Italy
| | - Rainer Waser
- Institut für Werkstoffe der Elektrotechnik 2, RWTH Aachen University, 52074, Aachen, Germany
- Peter Grünberg Institute, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Monica Santamaria
- Electrochemical Materials Science Laboratory, DICAM, Palermo University, Palermo, 90128, Italy
| | - Ilia Valov
- Institut für Werkstoffe der Elektrotechnik 2, RWTH Aachen University, 52074, Aachen, Germany
- Peter Grünberg Institute, Forschungszentrum Jülich, 52425, Jülich, Germany
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34
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Gunkel F, Jin L, Mueller DN, Hausner C, Bick DS, Jia CL, Schneller T, Valov I, Waser R, Dittmann R. Ordering and Phase Control in Epitaxial Double-Perovskite Catalysts for the Oxygen Evolution Reaction. ACS Catal 2017. [DOI: 10.1021/acscatal.7b02036] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Felix Gunkel
- Institute
of Electronic Materials (IWE2), RWTH Aachen University, 52074 Aachen, Germany
| | - Lei Jin
- Ernst
Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
- Peter
Gruenberg Institute and JARA-FIT, Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
| | - David N. Mueller
- Peter
Gruenberg Institute and JARA-FIT, Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
| | - Clemens Hausner
- Institute
of Electronic Materials (IWE2), RWTH Aachen University, 52074 Aachen, Germany
| | - Daniel S. Bick
- Institute
of Electronic Materials (IWE2), RWTH Aachen University, 52074 Aachen, Germany
| | - Chun-Lin Jia
- Ernst
Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
- Peter
Gruenberg Institute and JARA-FIT, Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
| | - Theodor Schneller
- Institute
of Electronic Materials (IWE2), RWTH Aachen University, 52074 Aachen, Germany
| | - Ilia Valov
- Peter
Gruenberg Institute and JARA-FIT, Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
| | - Rainer Waser
- Institute
of Electronic Materials (IWE2), RWTH Aachen University, 52074 Aachen, Germany
- Peter
Gruenberg Institute and JARA-FIT, Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
| | - Regina Dittmann
- Peter
Gruenberg Institute and JARA-FIT, Forschungszentrum Juelich GmbH, 52425 Juelich, Germany
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Cho DY, Luebben M, Wiefels S, Lee KS, Valov I. Interfacial Metal-Oxide Interactions in Resistive Switching Memories. ACS Appl Mater Interfaces 2017; 9:19287-19295. [PMID: 28508634 DOI: 10.1021/acsami.7b02921] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Metal oxides are commonly used as electrolytes for redox-based resistive switching memories. In most cases, non-noble metals are directly deposited as ohmic electrodes. We demonstrate that irrespective of bulk thermodynamics predictions an intermediate oxide film a few nanometers in thickness is always formed at the metal/insulator interface, and this layer significantly contributes to the development of reliable switching characteristics. We have tested metal electrodes and metal oxides mostly used for memristive devices, that is, Ta, Hf, and Ti and Ta2O5, HfO2, and SiO2. Intermediate oxide layers are always formed at the interfaces, whereas only the rate of the electrode oxidation depends on the oxygen affinity of the metal and the chemical stability of the oxide matrix. Device failure is associated with complete transition of short-range order to a more disordered main matrix structure.
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Affiliation(s)
- Deok-Yong Cho
- IPIT & Department of Physics, Chonbuk National University , Jeonju 54896, Korea
| | - Michael Luebben
- Peter Grünberg Institute (PGI-7), Research Centre Juelich , Juelich 52425, Germany
| | - Stefan Wiefels
- Peter Grünberg Institute (PGI-7), Research Centre Juelich , Juelich 52425, Germany
| | | | - Ilia Valov
- Peter Grünberg Institute (PGI-7), Research Centre Juelich , Juelich 52425, Germany
- Institute for Materials in Electrical Engineering II, RWTH Aachen University , Aachen 52074, Germany
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Celano U, Op de Beeck J, Clima S, Luebben M, Koenraad PM, Goux L, Valov I, Vandervorst W. Direct Probing of the Dielectric Scavenging-Layer Interface in Oxide Filamentary-Based Valence Change Memory. ACS Appl Mater Interfaces 2017; 9:10820-10824. [PMID: 28266834 DOI: 10.1021/acsami.6b16268] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A great improvement in valence change memory performance has been recently achieved by adding another metallic layer to the simple metal-insulator-metal (MIM) structure. This metal layer is often referred to as oxygen exchange layer (OEL) and is introduced between one of the electrodes and the oxide. The OEL is believed to induce a distributed reservoir of defects at the metal-insulator interface thus providing an unlimited availability of building blocks for the conductive filament (CF). However, its role remains elusive and controversial owing to the difficulties to probe the interface between the OEL and the CF. Here, using Scalpel SPM we probe multiple functions of the OEL which have not yet been directly measured, for two popular VCMs material systems: Hf/HfO2 and Ta/Ta2O5. We locate and characterize in three-dimensions the volume containing the oxygen exchange layer and the CF with nanometer lateral resolution. We demonstrate that the OEL induces a thermodynamic barrier for the CF and estimate the minimum thickness of the OEL/oxide interface to guarantee the proper switching operations is ca. 3 nm. Our experimental observations are combined to first-principles thermodynamics and defect kinetics to elucidate the role of the OEL for device optimization.
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Affiliation(s)
| | - Jonathan Op de Beeck
- IMEC , Kapeldreef 75, B-3001 Heverlee (Leuven), Belgium
- Department of Applied Physics, Eindhoven University of Technology , Eindhoven 5612AZ, The Netherlands
| | - Sergiu Clima
- IMEC , Kapeldreef 75, B-3001 Heverlee (Leuven), Belgium
| | - Michael Luebben
- Peter Grünberg Institute and Jülich Aachen Research Alliance , Jülich 52425, Germany
| | - Paul M Koenraad
- Department of Applied Physics, Eindhoven University of Technology , Eindhoven 5612AZ, The Netherlands
| | - Ludovic Goux
- Peter Grünberg Institute and Jülich Aachen Research Alliance , Jülich 52425, Germany
| | - Ilia Valov
- Peter Grünberg Institute and Jülich Aachen Research Alliance , Jülich 52425, Germany
| | - Wilfried Vandervorst
- IMEC , Kapeldreef 75, B-3001 Heverlee (Leuven), Belgium
- KU Leuven , Department of Physics and Astronomy, Celestijnenlaan 200D, B-3001 Leuven, Belgium
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Lübben M, Menzel S, Park SG, Yang M, Waser R, Valov I. SET kinetics of electrochemical metallization cells: influence of counter-electrodes in SiO 2/Ag based systems. Nanotechnology 2017; 28:135205. [PMID: 28248653 DOI: 10.1088/1361-6528/aa5e59] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The counter-electrode material in resistively switching electrochemical metallization cells (ECMs) is a crucial factor influencing the nucleation of conductive filaments, the equilibrium electrode potentials, and kinetics in the devices, and hence the overall switching characteristics. Here, we demonstrate the influence of the counter-electrode (CE) material on the SET events and the importance of appropriate choice and combination of materials. The counter-electrode material influences the counter-electrode processes at the CE/insulator interface and consequently determines the metal ion concentration in the cells. We measured the switching kinetics for SiO2/Ag based ECM cells using different counter-electrode materials with different electrocatalytic activities towards water reduction, namely platinum, ruthenium, and iridium oxide, as well as titanium nitride and tantalum. The experimental results are fitted using a physical simulation model and are analysed for the limiting factors for fast SET kinetics.
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Affiliation(s)
- M Lübben
- Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, D-52074 Aachen, Germany
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Affiliation(s)
- Ilia Valov
- Research Centre Juelich, Electronic Materials (PGI-7), 52425 Juelich, Germany.
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Abstract
It is now well known that at the nanoscale matters behave differently compared to bulk phases. Increased reactivity, deviations in structural, thermodynamic and kinetic properties make nanoscale materials and processes attractive for both fundamental research and applications. Here we show that nanometer thin films of materials with dielectric properties at the macroscopic level such as SiO2, Ta2O5 and HfO2 behave as solid electrolytes and exhibit evident ionic transport and electrochemical redox reactions. Experimental studies demonstrate that classical electrochemical potentiodynamic and steady state methods can be used to study the mass and charge transport at the nanoscale. We believe these reported properties of nanomatter open new opportunities for fundamental research and applications.
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Affiliation(s)
- Ilia Valov
- Research Centre Juelich, Electronic Materials (PGI-7), 52425 Juleich, Gemany
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Moors M, Adepalli KK, Lu Q, Wedig A, Bäumer C, Skaja K, Arndt B, Tuller HL, Dittmann R, Waser R, Yildiz B, Valov I. Resistive Switching Mechanisms on TaOx and SrRuO3 Thin-Film Surfaces Probed by Scanning Tunneling Microscopy. ACS Nano 2016; 10:1481-1492. [PMID: 26738414 DOI: 10.1021/acsnano.5b07020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The local electronic properties of tantalum oxide (TaOx, 2 ≤ x ≤ 2.5) and strontium ruthenate (SrRuO3) thin-film surfaces were studied under the influence of electric fields induced by a scanning tunneling microscope (STM) tip. The switching between different redox states in both oxides is achieved without the need for physical electrical contact by controlling the magnitude and polarity of the applied voltage between the STM tip and the sample surface. We demonstrate for TaOx films that two switching mechanisms operate. Reduced tantalum oxide shows resistive switching due to the formation of metallic Ta, but partial oxidation of the samples changes the switching mechanism to one mediated mainly by oxygen vacancies. For SrRuO3, we found that the switching mechanism depends on the polarity of the applied voltage and involves formation, annihilation, and migration of oxygen vacancies. Although TaOx and SrRuO3 differ significantly in their electronic and structural properties, the resistive switching mechanisms could be elaborated based on STM measurements, proving the general capability of this method for studying resistive switching phenomena in different classes of transition metal oxides.
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Affiliation(s)
- Marco Moors
- Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | | | | | - Anja Wedig
- Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | - Christoph Bäumer
- Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | - Katharina Skaja
- Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | - Benedikt Arndt
- Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | | | - Regina Dittmann
- Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | - Rainer Waser
- Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany
- Institut für Werkstoffe der Elektrotechnik 2, RWTH Aachen University , Sommerfeldstraße 24, 52074 Aachen, Germany
| | | | - Ilia Valov
- Peter Grünberg Institut, Forschungszentrum Jülich , Wilhelm-Johnen-Straße, 52425 Jülich, Germany
- Institut für Werkstoffe der Elektrotechnik 2, RWTH Aachen University , Sommerfeldstraße 24, 52074 Aachen, Germany
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Wedig A, Luebben M, Cho DY, Moors M, Skaja K, Rana V, Hasegawa T, Adepalli KK, Yildiz B, Waser R, Valov I. Nanoscale cation motion in TaO(x), HfO(x) and TiO(x) memristive systems. Nat Nanotechnol 2016; 11:67-74. [PMID: 26414197 DOI: 10.1038/nnano.2015.221] [Citation(s) in RCA: 195] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 08/25/2015] [Indexed: 05/27/2023]
Abstract
A detailed understanding of the resistive switching mechanisms that operate in redox-based resistive random-access memories (ReRAM) is key to controlling these memristive devices and formulating appropriate design rules. Based on distinct fundamental switching mechanisms, two types of ReRAM have emerged: electrochemical metallization memories, in which the mobile species is thought to be metal cations, and valence change memories, in which the mobile species is thought to be oxygen anions (or positively charged oxygen vacancies). Here we show, using scanning tunnelling microscopy and supported by potentiodynamic current-voltage measurements, that in three typical valence change memory materials (TaO(x), HfO(x) and TiO(x)) the host metal cations are mobile in films of 2 nm thickness. The cations can form metallic filaments and participate in the resistive switching process, illustrating that there is a bridge between the electrochemical metallization mechanism and the valence change mechanism. Reset/Set operations are, we suggest, driven by oxidation (passivation) and reduction reactions. For the Ta/Ta2O5 system, a rutile-type TaO2 film is believed to mediate switching, and we show that devices can be switched from a valence change mode to an electrochemical metallization mode by introducing an intermediate layer of amorphous carbon.
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Affiliation(s)
- Anja Wedig
- Peter Gruenberg Institute, Research Centre Juelich, Juelich 52425, Germany
| | - Michael Luebben
- Peter Gruenberg Institute, Research Centre Juelich, Juelich 52425, Germany
| | - Deok-Yong Cho
- Department of Physics, Chonbuk National University, Jeonju 561-756, Korea
| | - Marco Moors
- Peter Gruenberg Institute, Research Centre Juelich, Juelich 52425, Germany
| | - Katharina Skaja
- Peter Gruenberg Institute, Research Centre Juelich, Juelich 52425, Germany
| | - Vikas Rana
- Peter Gruenberg Institute, Research Centre Juelich, Juelich 52425, Germany
| | - Tsuyoshi Hasegawa
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Kiran K Adepalli
- Department of Nuclear Science and Engineering, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Bilge Yildiz
- Department of Nuclear Science and Engineering, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Rainer Waser
- Peter Gruenberg Institute, Research Centre Juelich, Juelich 52425, Germany
- Institute for Materials in Electrical Engineering II, RWTH Aachen University, Sommerfeldstrasse 24, Aachen 52074, Germany
| | - Ilia Valov
- Peter Gruenberg Institute, Research Centre Juelich, Juelich 52425, Germany
- Institute for Materials in Electrical Engineering II, RWTH Aachen University, Sommerfeldstrasse 24, Aachen 52074, Germany
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Lübben M, Karakolis P, Ioannou-Sougleridis V, Normand P, Dimitrakis P, Valov I. Graphene-Modified Interface Controls Transition from VCM to ECM Switching Modes in Ta/TaOx Based Memristive Devices. Adv Mater 2015; 27:6202-7. [PMID: 26456484 DOI: 10.1002/adma.201502574] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 07/22/2015] [Indexed: 05/26/2023]
Abstract
By modification of the electrode-solid-electrolyte interface with graphene, transit from valence change memories (VCM) to electrochemical metallization memories (ECM) in the cell Ta(C)/Ta2 O5 /Pt is demonstrated, thus, bridging both mechanisms. The ECM operation is discussed in the light of Ta-cation mobility in TaOx . The crucial role of electrochemical processes and moisture in the resistive switching process is also highlighted.
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Affiliation(s)
- Michael Lübben
- Peter Grünberg Institute (Electronic Materials - PGI-7), Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Panagiotis Karakolis
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, 15310, Athens, Greece
| | | | - Pascal Normand
- Institute of Nanoscience and Nanotechnology, NCSR Demokritos, 15310, Athens, Greece
| | | | - Ilia Valov
- Peter Grünberg Institute (Electronic Materials - PGI-7), Forschungszentrum Jülich, 52425, Jülich, Germany
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Shang D, Li P, Wang T, Carria E, Sun J, Shen B, Taubner T, Valov I, Waser R, Wuttig M. Understanding the conductive channel evolution in Na:WO(3-x)-based planar devices. Nanoscale 2015; 7:6023-6030. [PMID: 25766380 DOI: 10.1039/c4nr07545e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An ion migration process in a solid electrolyte is important for ion-based functional devices, such as fuel cells, batteries, electrochromics, gas sensors, and resistive switching systems. In this study, a planar sandwich structure is prepared by depositing tungsten oxide (WO(3-x)) films on a soda-lime glass substrate, from which Na(+) diffuses into the WO(3-x) films during the deposition. The entire process of Na(+) migration driven by an alternating electric field is visualized in the Na-doped WO(3-x) films in the form of conductive channel by in situ optical imaging combined with infrared spectroscopy and near-field imaging techniques. A reversible change of geometry between a parabolic and a bar channel is observed with the resistance change of the devices. The peculiar channel evolution is interpreted by a thermal-stress-induced mechanical deformation of the films and an asymmetric Na(+) mobility between the parabolic and the bar channels. These results exemplify a typical ion migration process driven by an alternating electric field in a solid electrolyte with a low ion mobility and are expected to be beneficial to improve the controllability of the ion migration in ion-based functional devices, such as resistive switching devices.
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Affiliation(s)
- Dashan Shang
- I. Physikalisches Institut (IA), RWTH Aachen University, 52074 Aachen, Germany.
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Lübben M, Karakolis P, Wedig A, Ioannou V, Normand P, Dimitrakis P, Valov I. Influence of Graphene Interlayers on Electrode-Electrolyte Interfaces in Resistive Random Accesses Memory Cells. ACTA ACUST UNITED AC 2015. [DOI: 10.1557/opl.2015.213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTThe behavior of the redox-based resistive switching memories is influenced by chemical interactions between the electrode and the solid electrolyte, as well as by local environment. The existence of different chemical potential gradients is resulting in nanobattery effect lowering the stability of the devices. In order to minimize these effects we introduce a graphene layer at the active electrode – solid electrolyte interface. We observe that graphene is acting as an effective diffusion barrier in the SiO2-based electrochemical metallization cells and acts catalytically on the electrochemical processes prior to resistive switching.
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van den Hurk J, Linn E, Zhang H, Waser R, Valov I. Volatile resistance states in electrochemical metallization cells enabling non-destructive readout of complementary resistive switches. Nanotechnology 2014; 25:425202. [PMID: 25266966 DOI: 10.1088/0957-4484/25/42/425202] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Redox-based resistive memory cells exhibit changes of OFF or intermediate resistance values over time and even ON states can be completely lost in certain cases. The stability of these resistance states and the time until resistance loss strongly depends on the materials system. On the basis of electrical measurements and chemical analysis we found a viable explanation for these volatile resistance states (VRSs) in Ag-GeSx-based electrochemical metallization memory cells and identified a technological application in the field of crossbar memories. Complementary resistive switches usually suffer from the necessity of a destructive read-out procedure increasing wear and reducing read-out speed. From our analysis we deduced a solution to use the VRS as an inherent selector mechanism without the need for additional selector devices.
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Affiliation(s)
- Jan van den Hurk
- Institut für Werkstoffe der Elektrotechnik II (IWE II) & JARA-FIT, RWTH Aachen University, Sommerfeldstr. 24, D-52074 Aachen, Germany
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Tappertzhofen S, Waser R, Valov I. Inside Back Cover: Impact of the Counter-Electrode Material on Redox Processes in Resistive Switching Memories (ChemElectroChem 8/2014). ChemElectroChem 2014. [DOI: 10.1002/celc.201402225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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van den Hurk J, Dippel AC, Cho DY, Straquadine J, Breuer U, Walter P, Waser R, Valov I. Physical origins and suppression of Ag dissolution in GeSx-based ECM cells. Phys Chem Chem Phys 2014; 16:18217-25. [DOI: 10.1039/c4cp01759e] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tappertzhofen S, Waser R, Valov I. Impact of the Counter-Electrode Material on Redox Processes in Resistive Switching Memories. ChemElectroChem 2014. [DOI: 10.1002/celc.201402106] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Yang Y, Gao P, Li L, Pan X, Tappertzhofen S, Choi S, Waser R, Valov I, Lu WD. Electrochemical dynamics of nanoscale metallic inclusions in dielectrics. Nat Commun 2014; 5:4232. [PMID: 24953477 DOI: 10.1038/ncomms5232] [Citation(s) in RCA: 212] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 05/28/2014] [Indexed: 12/11/2022] Open
Abstract
Nanoscale metal inclusions in or on solid-state dielectrics are an integral part of modern electrocatalysis, optoelectronics, capacitors, metamaterials and memory devices. The properties of these composite systems strongly depend on the size, dispersion of the inclusions and their chemical stability, and are usually considered constant. Here we demonstrate that nanoscale inclusions (for example, clusters) in dielectrics dynamically change their shape, size and position upon applied electric field. Through systematic in situ transmission electron microscopy studies, we show that fundamental electrochemical processes can lead to universally observed nucleation and growth of metal clusters, even for inert metals like platinum. The clusters exhibit diverse dynamic behaviours governed by kinetic factors including ion mobility and redox rates, leading to different filament growth modes and structures in memristive devices. These findings reveal the microscopic origin behind resistive switching, and also provide general guidance for the design of novel devices involving electronics and ionics.
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Affiliation(s)
- Yuchao Yang
- Department of Electrical Engineering and Computer Science, the University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Peng Gao
- 1] Department of Materials Science and Engineering, the University of Michigan, Ann Arbor, Michigan 48109, USA [2]
| | - Linze Li
- Department of Materials Science and Engineering, the University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Xiaoqing Pan
- Department of Materials Science and Engineering, the University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Stefan Tappertzhofen
- Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, 52074 Aachen, Germany
| | - ShinHyun Choi
- Department of Electrical Engineering and Computer Science, the University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Rainer Waser
- 1] Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, 52074 Aachen, Germany [2] Peter Grünberg Institute 7, Research Centre Jülich GmbH, 52425 Jülich, Germany
| | - Ilia Valov
- 1] Institut für Werkstoffe der Elektrotechnik II, RWTH Aachen University, 52074 Aachen, Germany [2] Peter Grünberg Institute 7, Research Centre Jülich GmbH, 52425 Jülich, Germany
| | - Wei D Lu
- Department of Electrical Engineering and Computer Science, the University of Michigan, Ann Arbor, Michigan 48109, USA
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