1
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Youn S, Hwang Y, Kim TH, Kim S, Hwang H, Park J, Kim H. Threshold learning algorithm for memristive neural network with binary switching behavior. Neural Netw 2024; 176:106355. [PMID: 38759411 DOI: 10.1016/j.neunet.2024.106355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 02/04/2024] [Accepted: 04/29/2024] [Indexed: 05/19/2024]
Abstract
On-chip learning is an effective method for adjusting artificial neural networks in neuromorphic computing systems by considering hardware intrinsic properties. However, it faces challenges due to hardware nonidealities, such as the nonlinearity of potentiation and depression and limitations on fine weight adjustment. In this study, we propose a threshold learning algorithm for a variation-tolerant ternary neural network in a memristor crossbar array. This algorithm utilizes two tightly separated resistance states in memristive devices to represent weight values. The high-resistance state (HRS) and low-resistance state (LRS) defined as read current of < 0.1 μA and > 1 μA, respectively, were successfully programmed in a 32 × 32 crossbar array, and exhibited half-normal distributions due to the programming method. To validate our approach experimentally, a 64 × 10 single-layer fully connected network were trained in the fabricated crossbar for an 8 × 8 MNIST dataset using the threshold learning algorithm, where the weight value is updated when a gradient determined by backpropagation exceeds a threshold value. Thanks to the large margin between the two states of the memristor, we observed only a 0.42 % drop in classification accuracy compared to the baseline network results. The threshold learning algorithm is expected to alleviate the programming burden and be utilized in variation-tolerant neuromorphic architectures.
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Affiliation(s)
- Sangwook Youn
- Division of Materials Science and Engineering, Seoul 04763, Korea
| | - Yeongjin Hwang
- Department of Electrical and Computer Engineering, Inha University, Incheon 22212, Korea
| | - Tae-Hyeon Kim
- Department of Semiconductor Engineering, Seoul National University of Science and Technology, Seoul 01811, Korea
| | - Sungjoon Kim
- Department of AI Semiconductor Engineering, Korea University, Sejong 30019, Korea
| | - Hwiho Hwang
- Division of Materials Science and Engineering, Seoul 04763, Korea
| | - Jinwoo Park
- Division of Materials Science and Engineering, Seoul 04763, Korea
| | - Hyungjin Kim
- Division of Materials Science and Engineering, Seoul 04763, Korea.
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2
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Jang YH, Lee SH, Han J, Cheong S, Shim SK, Han JK, Ryoo SK, Hwang CS. Memristive Crossbar Array-Based Probabilistic Graph Modeling. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2403904. [PMID: 39030848 DOI: 10.1002/adma.202403904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Revised: 07/05/2024] [Indexed: 07/22/2024]
Abstract
Modern graph datasets with structural complexity and uncertainties due to incomplete information or data variability require advanced modeling techniques beyond conventional graph models. This study introduces a memristive crossbar array (CBA)-based probabilistic graph model (C-PGM) utilizing Cu0.3Te0.7/HfO2/Pt memristors, which exhibit probabilistic switching, self-rectifying, and memory characteristics. C-PGM addresses the complexities and uncertainties inherent in structural graph data across various domains, leveraging the probabilistic nature of memristors. C-PGM relies on the device-to-device variation across multiple memristive CBAs, overcoming the limitations of previous approaches that rely on sequential operations, which are slower and have a reliability concern due to repeated switching. This new approach enables the fast processing and massive implementation of probabilistic units at the expense of chip area. In this study, the hardware-based C-PGM feasibly expresses small-scale probabilistic graphs and shows minimal error in aggregate probability calculations. The probability calculation capabilities of C-PGM are applied to steady-state estimation and the PageRank algorithm, which is implemented on a simulated large-scale C-PGM. The C-PGM-based steady-state estimation and PageRank algorithm demonstrate comparable accuracy to conventional methods while significantly reducing computational costs.
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Affiliation(s)
- Yoon Ho Jang
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Soo Hyung Lee
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Janguk Han
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sunwoo Cheong
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sung Keun Shim
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Joon-Kyu Han
- System Semiconductor Engineering and Department of Electronic Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul, 04107, Republic of Korea
| | - Seung Kyu Ryoo
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Cheol Seong Hwang
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
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3
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Lee ST, Lee JH. Review of neuromorphic computing based on NAND flash memory. NANOSCALE HORIZONS 2024. [PMID: 39015048 DOI: 10.1039/d3nh00532a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
The proliferation of data has facilitated global accessibility, which demands escalating amounts of power for data storage and processing purposes. In recent years, there has been a rise in research in the field of neuromorphic electronics, which draws inspiration from biological neurons and synapses. These electronics possess the ability to perform in-memory computing, which helps alleviate the limitations imposed by the 'von Neumann bottleneck' that exists between the memory and processor in the traditional von Neumann architecture. By leveraging their multi-bit non-volatility, characteristics that mimic biology, and Kirchhoff's law, neuromorphic electronics offer a promising solution to reduce the power consumption in processing vector-matrix multiplication tasks. Among all the existing nonvolatile memory technologies, NAND flash memory is one of the most competitive integrated solutions for the storage of large volumes of data. This work provides a comprehensive overview of the recent developments in neuromorphic computing based on NAND flash memory. Neuromorphic architectures using NAND flash memory for off-chip learning are presented with various quantization levels of input and weight. Next, neuromorphic architectures for on-chip learning are presented using standard backpropagation and feedback alignment algorithms. The array architecture, operation scheme, and electrical characteristics of NAND flash memory are discussed with a focus on the use of NAND flash memory in various neural network structures. Furthermore, the discrepancy of array architecture between on-chip learning and off-chip learning is addressed. This review article provides a foundation for understanding the neuromorphic computing based on the NAND flash memory and methods to utilize it based on application requirements.
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Affiliation(s)
- Sung-Tae Lee
- School of Electronic and Electrical Engineering, Hongik University, Seoul 04066, Republic of Korea.
| | - Jong-Ho Lee
- The Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Republic of Korea.
- Minstry of Sciecne and ICT, Sejong, Korea
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4
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Shim SK, Jang YH, Han J, Jeon JW, Shin DH, Kim YR, Han JK, Woo KS, Lee SH, Cheong S, Kim J, Seo H, Shin J, Hwang CS. 2Memristor-1Capacitor Integrated Temporal Kernel for High-Dimensional Data Mapping. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2306585. [PMID: 38212281 DOI: 10.1002/smll.202306585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 12/01/2023] [Indexed: 01/13/2024]
Abstract
Compact but precise feature-extracting ability is core to processing complex computational tasks in neuromorphic hardware. Physical reservoir computing (RC) offers a robust framework to map temporal data into a high-dimensional space using the time dynamics of a material system, such as a volatile memristor. However, conventional physical RC systems have limited dynamics for the given material properties, restricting the methods to increase their dimensionality. This study proposes an integrated temporal kernel composed of a 2-memristor and 1-capacitor (2M1C) using a W/HfO2/TiN memristor and TiN/ZrO2/Al2O3/ZrO2/TiN capacitor to achieve higher dimensionality and tunable dynamics. The kernel elements are carefully designed and fabricated into an integrated array, of which performances are evaluated under diverse conditions. By optimizing the time dynamics of the 2M1C kernel, each memristor simultaneously extracts complementary information from input signals. The MNIST benchmark digit classification task achieves a high accuracy of 94.3% with a (196×10) single-layer network. Analog input mapping ability is tested with a Mackey-Glass time series prediction, and the system records a normalized root mean square error of 0.04 with a 20×1 readout network, the smallest readout network ever used for Mackey-Glass prediction in RC. These performances demonstrate its high potential for efficient temporal data analysis.
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Affiliation(s)
- Sung Keun Shim
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Yoon Ho Jang
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Janguk Han
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jeong Woo Jeon
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Dong Hoon Shin
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Yeong Rok Kim
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Joon-Kyu Han
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Kyung Seok Woo
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Soo Hyung Lee
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sunwoo Cheong
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jaehyun Kim
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Haengha Seo
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jonghoon Shin
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Cheol Seong Hwang
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
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5
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Lee JH, Cho K, Kim JK. Age of Flexible Electronics: Emerging Trends in Soft Multifunctional Sensors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2310505. [PMID: 38258951 DOI: 10.1002/adma.202310505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/27/2023] [Indexed: 01/24/2024]
Abstract
With the commercialization of first-generation flexible mobiles and displays in the late 2010s, humanity has stepped into the age of flexible electronics. Inevitably, soft multifunctional sensors, as essential components of next-generation flexible electronics, have attracted tremendous research interest like never before. This review is dedicated to offering an overview of the latest emerging trends in soft multifunctional sensors and their accordant future research and development (R&D) directions for the coming decade. First, key characteristics and the predominant target stimuli for soft multifunctional sensors are highlighted. Second, important selection criteria for soft multifunctional sensors are introduced. Next, emerging materials/structures and trends for soft multifunctional sensors are identified. Specifically, the future R&D directions of these sensors are envisaged based on their emerging trends, namely i) decoupling of multiple stimuli, ii) data processing, iii) skin conformability, and iv) energy sources. Finally, the challenges and potential opportunities for these sensors in future are discussed, offering new insights into prospects in the fast-emerging technology.
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Affiliation(s)
- Jeng-Hun Lee
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 37673, South Korea
| | - Kilwon Cho
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 37673, South Korea
| | - Jang-Kyo Kim
- Department of Mechanical Engineering, Khalifa University, P. O. Box 127788, Abu Dhabi, United Arab Emirates
- School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, NSW, 2052, Australia
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6
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Lim B, Lee YM, Yoo CS, Kim M, Kim SJ, Kim S, Yang JJ, Lee HS. High-Reliability and Self-Rectifying Alkali Ion Memristor through Bottom Electrode Design and Dopant Incorporation. ACS NANO 2024; 18:6373-6386. [PMID: 38349619 PMCID: PMC10906085 DOI: 10.1021/acsnano.3c11325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 02/28/2024]
Abstract
Ionic memristor devices are crucial for efficient artificial neural network computations in neuromorphic hardware. They excel in multi-bit implementation but face challenges like device reliability and sneak currents in crossbar array architecture (CAA). Interface-type ionic memristors offer low variation, self-rectification, and no forming process, making them suitable for CAA. However, they suffer from slow weight updates and poor retention and endurance. To address these issues, the study demonstrated an alkali ion self-rectifying memristor with an alkali metal reservoir formed by a bottom electrode design. By adopting Li metal as the adhesion layer of the bottom electrode, an alkali ion reservoir was formed at the bottom of the memristor layer by diffusion occurring during the atomic layer deposition process for the Na:TiO2 memristor layer. In addition, Al dopant was used to improve the retention characteristics by suppressing the diffusion of alkali cations. In the memristor device with optimized Al doping, retention characteristics of more than 20 h at 125 °C, endurance characteristics of more than 5.5 × 105, and high linearity/symmetry of weight update characteristics were achieved. In reliability tests on 100 randomly selected devices from a 32 × 32 CAA device, device-to-device and cycle-to-cycle variations showed low variation values within 81% and 8%, respectively.
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Affiliation(s)
- Byeong
Min Lim
- Department
of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated
Education Institute for Frontier Science & Technology (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Yu Min Lee
- Department
of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated
Education Institute for Frontier Science & Technology (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Chan Sik Yoo
- Department
of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated
Education Institute for Frontier Science & Technology (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Minjae Kim
- Department
of Electrical and Computer Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Seung Ju Kim
- Department
of Electrical and Computer Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Sungkyu Kim
- HMC,
Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 05006, Republic of Korea
| | - J. Joshua Yang
- Department
of Electrical and Computer Engineering, University of Southern California, Los Angeles, California 90089, United States
| | - Hong-Sub Lee
- Department
of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated
Education Institute for Frontier Science & Technology (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
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7
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Fernandes J, Grzonka J, Araújo G, Schulman A, Silva V, Rodrigues J, Santos J, Bondarchuk O, Ferreira P, Alpuim P, Capasso A. Bipolar Resistive Switching in 2D MoSe 2 Grown by Atmospheric Pressure Chemical Vapor Deposition. ACS APPLIED MATERIALS & INTERFACES 2024; 16:1767-1778. [PMID: 38113456 DOI: 10.1021/acsami.3c14215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Two-dimensional (2D) transition metal dichalcogenides (TMDCs) are highly promising nanomaterials for various electronic devices such as field-effect transistors, junction diodes, tunneling devices, and, more recently, memristors. 2D MoSe2 stands out for having high electrical conductivity, charge carrier mobility, and melting point. While these features make it particularly appropriate as a switching layer in memristive devices, reliable and scalable production of large-area 2D MoSe2 still represents a challenge. In this study, we manufacture 2D MoSe2 films by atmospheric-pressure chemical vapor deposition and investigate them on the atomic scale. We selected and transferred MoSe2 bilayer to serve as a switching layer between asymmetric Au-Cu electrodes in miniaturized crossbar vertical memristors. The electrochemical metallization devices showed forming-free, bipolar resistive switching at low voltages, with clearly identifiable nonvolatile states. Other than low-power neuromorphic computing, low switching voltages approaching the range of biological action potentials could unlock hybrid biological interfaces.
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Affiliation(s)
- João Fernandes
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
| | - Justyna Grzonka
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
| | - Guilherme Araújo
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
| | - Alejandro Schulman
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
- Wihuri Physical Laboratory, Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland
| | - Vitor Silva
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
| | - João Rodrigues
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
| | - João Santos
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
| | | | - Paulo Ferreira
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
- Mechanical Engineering Department and IDMEC, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- Materials Science and Engineering Program, University of Texas at Austin, Austin, Texas 78712, United States
| | - Pedro Alpuim
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
- Centro de Física das Universidades do Minho e do Porto, Universidade do Minho, 4710-057 Braga, Portugal
| | - Andrea Capasso
- International Iberian Nanotechnology Laboratory, 4715-330 Braga, Portugal
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8
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Jang YH, Han J, Shim SK, Cheong S, Lee SH, Han JK, Hwang CS. Cross-Wired Memristive Crossbar Array for Effective Graph Data Analysis. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2311040. [PMID: 38145578 DOI: 10.1002/adma.202311040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 12/06/2023] [Indexed: 12/27/2023]
Abstract
Graphs adequately represent the enormous interconnections among numerous entities in big data, incurring high computational costs in analyzing them with conventional hardware. Physical graph representation (PGR) is an approach that replicates the graph within a physical system, allowing for efficient analysis. This study introduces a cross-wired crossbar array (cwCBA), uniquely connecting diagonal and non-diagonal components in a CBA by a cross-wiring process. The cross-wired diagonal cells enable cwCBA to achieve precise PGR and dynamic node state control. For this purpose, a cwCBA is fabricated using Pt/Ta2 O5 /HfO2 /TiN (PTHT) memristor with high on/off and self-rectifying characteristics. The structural and device benefits of PTHT cwCBA for enhanced PGR precision are highlighted, and the practical efficacy is demonstrated for two applications. First, it executes a dynamic path-finding algorithm, identifying the shortest paths in a dynamic graph. PTHT cwCBA shows a more accurate inferred distance and ≈1/3800 lower processing complexity than the conventional method. Second, it analyzes the protein-protein interaction (PPI) networks containing self-interacting proteins, which possess intricate characteristics compared to typical graphs. The PPI prediction results exhibit an average of 30.5% and 21.3% improvement in area under the curve and F1-score, respectively, compared to existing algorithms.
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Affiliation(s)
- Yoon Ho Jang
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Janguk Han
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sung Keun Shim
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sunwoo Cheong
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Soo Hyung Lee
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Joon-Kyu Han
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Cheol Seong Hwang
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
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9
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Xu M, Chen X, Guo Y, Wang Y, Qiu D, Du X, Cui Y, Wang X, Xiong J. Reconfigurable Neuromorphic Computing: Materials, Devices, and Integration. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2301063. [PMID: 37285592 DOI: 10.1002/adma.202301063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 05/15/2023] [Indexed: 06/09/2023]
Abstract
Neuromorphic computing has been attracting ever-increasing attention due to superior energy efficiency, with great promise to promote the next wave of artificial general intelligence in the post-Moore era. Current approaches are, however, broadly designed for stationary and unitary assignments, thus encountering reluctant interconnections, power consumption, and data-intensive computing in that domain. Reconfigurable neuromorphic computing, an on-demand paradigm inspired by the inherent programmability of brain, can maximally reallocate finite resources to perform the proliferation of reproducibly brain-inspired functions, highlighting a disruptive framework for bridging the gap between different primitives. Although relevant research has flourished in diverse materials and devices with novel mechanisms and architectures, a precise overview remains blank and urgently desirable. Herein, the recent strides along this pursuit are systematically reviewed from material, device, and integration perspectives. At the material and device level, one comprehensively conclude the dominant mechanisms for reconfigurability, categorized into ion migration, carrier migration, phase transition, spintronics, and photonics. Integration-level developments for reconfigurable neuromorphic computing are also exhibited. Finally, a perspective on the future challenges for reconfigurable neuromorphic computing is discussed, definitely expanding its horizon for scientific communities.
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Affiliation(s)
- Minyi Xu
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xinrui Chen
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Yehao Guo
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Yang Wang
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Dong Qiu
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xinchuan Du
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Yi Cui
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Xianfu Wang
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Jie Xiong
- State Key Laboratory of Electronic Thin Film and Integrated Devices, School of Physics, University of Electronic Science and Technology of China, Chengdu, 610054, China
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10
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Park JY, Choe DH, Lee DH, Yu GT, Yang K, Kim SH, Park GH, Nam SG, Lee HJ, Jo S, Kuh BJ, Ha D, Kim Y, Heo J, Park MH. Revival of Ferroelectric Memories Based on Emerging Fluorite-Structured Ferroelectrics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2204904. [PMID: 35952355 DOI: 10.1002/adma.202204904] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/25/2022] [Indexed: 06/15/2023]
Abstract
Over the last few decades, the research on ferroelectric memories has been limited due to their dimensional scalability and incompatibility with complementary metal-oxide-semiconductor (CMOS) technology. The discovery of ferroelectricity in fluorite-structured oxides revived interest in the research on ferroelectric memories, by inducing nanoscale nonvolatility in state-of-the-art gate insulators by minute doping and thermal treatment. The potential of this approach has been demonstrated by the fabrication of sub-30 nm electronic devices. Nonetheless, to realize practical applications, various technical limitations, such as insufficient reliability including endurance, retention, and imprint, as well as large device-to-device-variation, require urgent solutions. Furthermore, such limitations should be considered based on targeting devices as well as applications. Various types of ferroelectric memories including ferroelectric random-access-memory, ferroelectric field-effect-transistor, and ferroelectric tunnel junction should be considered for classical nonvolatile memories as well as emerging neuromorphic computing and processing-in-memory. Therefore, from the viewpoint of materials science, this review covers the recent research focusing on ferroelectric memories from the history of conventional approaches to future prospects.
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Affiliation(s)
- Ju Yong Park
- Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea
| | - Duk-Hyun Choe
- Beyond Silicon Lab, Samsung Advanced Institute of Technology (SAIT), Suwon, 16678, Republic of Korea
| | - Dong Hyun Lee
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Geun Taek Yu
- School of Materials Science and Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Kun Yang
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Se Hyun Kim
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Geun Hyeong Park
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Seung-Geol Nam
- Beyond Silicon Lab, Samsung Advanced Institute of Technology (SAIT), Suwon, 16678, Republic of Korea
| | - Hyun Jae Lee
- Beyond Silicon Lab, Samsung Advanced Institute of Technology (SAIT), Suwon, 16678, Republic of Korea
| | - Sanghyun Jo
- Beyond Silicon Lab, Samsung Advanced Institute of Technology (SAIT), Suwon, 16678, Republic of Korea
| | - Bong Jin Kuh
- Semiconductor Research and Development Center, Samsung Electronics, Hwaseong, 18448, Republic of Korea
| | - Daewon Ha
- Semiconductor Research and Development Center, Samsung Electronics, Hwaseong, 18448, Republic of Korea
| | - Yongsung Kim
- Beyond Silicon Lab, Samsung Advanced Institute of Technology (SAIT), Suwon, 16678, Republic of Korea
| | - Jinseong Heo
- Beyond Silicon Lab, Samsung Advanced Institute of Technology (SAIT), Suwon, 16678, Republic of Korea
| | - Min Hyuk Park
- Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
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11
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Park TJ, Deng S, Manna S, Islam ANMN, Yu H, Yuan Y, Fong DD, Chubykin AA, Sengupta A, Sankaranarayanan SKRS, Ramanathan S. Complex Oxides for Brain-Inspired Computing: A Review. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2203352. [PMID: 35723973 DOI: 10.1002/adma.202203352] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/02/2022] [Indexed: 06/15/2023]
Abstract
The fields of brain-inspired computing, robotics, and, more broadly, artificial intelligence (AI) seek to implement knowledge gleaned from the natural world into human-designed electronics and machines. In this review, the opportunities presented by complex oxides, a class of electronic ceramic materials whose properties can be elegantly tuned by doping, electron interactions, and a variety of external stimuli near room temperature, are discussed. The review begins with a discussion of natural intelligence at the elementary level in the nervous system, followed by collective intelligence and learning at the animal colony level mediated by social interactions. An important aspect highlighted is the vast spatial and temporal scales involved in learning and memory. The focus then turns to collective phenomena, such as metal-to-insulator transitions (MITs), ferroelectricity, and related examples, to highlight recent demonstrations of artificial neurons, synapses, and circuits and their learning. First-principles theoretical treatments of the electronic structure, and in situ synchrotron spectroscopy of operating devices are then discussed. The implementation of the experimental characteristics into neural networks and algorithm design is then revewed. Finally, outstanding materials challenges that require a microscopic understanding of the physical mechanisms, which will be essential for advancing the frontiers of neuromorphic computing, are highlighted.
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Affiliation(s)
- Tae Joon Park
- School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Sunbin Deng
- School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Sukriti Manna
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - A N M Nafiul Islam
- Department of Electrical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Haoming Yu
- School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Yifan Yuan
- School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Dillon D Fong
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Alexander A Chubykin
- Department of Biological Sciences, Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Abhronil Sengupta
- Department of Electrical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Subramanian K R S Sankaranarayanan
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL, 60439, USA
- Department of Mechanical and Industrial Engineering, University of Illinois Chicago, Chicago, IL, 60607, USA
| | - Shriram Ramanathan
- School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA
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12
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Liu H, Qin Y, Chen HY, Wu J, Ma J, Du Z, Wang N, Zou J, Lin S, Zhang X, Zhang Y, Wang H. Artificial Neuronal Devices Based on Emerging Materials: Neuronal Dynamics and Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2205047. [PMID: 36609920 DOI: 10.1002/adma.202205047] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Artificial neuronal devices are critical building blocks of neuromorphic computing systems and currently the subject of intense research motivated by application needs from new computing technology and more realistic brain emulation. Researchers have proposed a range of device concepts that can mimic neuronal dynamics and functions. Although the switching physics and device structures of these artificial neurons are largely different, their behaviors can be described by several neuron models in a more unified manner. In this paper, the reports of artificial neuronal devices based on emerging volatile switching materials are reviewed from the perspective of the demonstrated neuron models, with a focus on the neuronal functions implemented in these devices and the exploitation of these functions for computational and sensing applications. Furthermore, the neuroscience inspirations and engineering methods to enrich the neuronal dynamics that remain to be implemented in artificial neuronal devices and networks toward realizing the full functionalities of biological neurons are discussed.
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Affiliation(s)
- Hefei Liu
- Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Yuan Qin
- Center for Power Electronics Systems, Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24060, USA
| | - Hung-Yu Chen
- Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Jiangbin Wu
- Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Jiahui Ma
- Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Zhonghao Du
- Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, 90089, USA
| | - Nan Wang
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA, 90089, USA
| | - Jingyi Zou
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Sen Lin
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Xu Zhang
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
| | - Yuhao Zhang
- Center for Power Electronics Systems, Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, 24060, USA
| | - Han Wang
- Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, 90089, USA
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA, 90089, USA
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13
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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. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2301924. [PMID: 37199224 DOI: 10.1002/adma.202301924] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [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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14
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Kim HI, Lee T, Cho Y, Lee S, Lee WY, Kim K, Jang J. Sol-Gel-Processed Y 2O 3-Al 2O 3 Mixed Oxide-Based Resistive Random-Access-Memory Devices. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2462. [PMID: 37686969 PMCID: PMC10490390 DOI: 10.3390/nano13172462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 08/26/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023]
Abstract
Herein, sol-gel-processed Y2O3-Al2O3 mixed oxide-based resistive random-access-memory (RRAM) devices with different proportions of the involved Y2O3 and Al2O3 precursors were fabricated on indium tin oxide/glass substrates. The corresponding structural, chemical, and electrical properties were investigated. The fabricated devices exhibited conventional bipolar RRAM characteristics without requiring a high-voltage forming process. With an increase in the percentage of Al2O3 precursor above 50 mol%, the crystallinity reduced, with the amorphous phase increasing owing to internal stress. Moreover, with increasing Al2O3 percentage, the lattice oxygen percentage increased and the oxygen vacancy percentage decreased. A 50% Y2O3-50% Al2O3 mixed oxide-based RRAM device exhibited the maximum high-resistance-state/low-resistance-state (HRS/LRS) ratio, as required for a large readout margin and array size. Additionally, this device demonstrated good endurance characteristics, maintaining stability for approximately 100 cycles with a high HRS/LRS ratio (>104). The HRS and LRS resistances were also retained up to 104 s without considerable degradation.
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Affiliation(s)
- Hae-In Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (H.-I.K.); (T.L.); (Y.C.); (S.L.); (W.-Y.L.)
| | - Taehun Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (H.-I.K.); (T.L.); (Y.C.); (S.L.); (W.-Y.L.)
| | - Yoonjin Cho
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (H.-I.K.); (T.L.); (Y.C.); (S.L.); (W.-Y.L.)
| | - Sangwoo Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (H.-I.K.); (T.L.); (Y.C.); (S.L.); (W.-Y.L.)
| | - Won-Yong Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (H.-I.K.); (T.L.); (Y.C.); (S.L.); (W.-Y.L.)
- The Institute of Electronic Technology, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Kwangeun Kim
- School of Electronics and Information Engineering, Korea Aerospace University, Goyang 10540, Republic of Korea
| | - Jaewon Jang
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (H.-I.K.); (T.L.); (Y.C.); (S.L.); (W.-Y.L.)
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15
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Lee T, Kim HI, Cho Y, Lee S, Lee WY, Bae JH, Kang IM, Kim K, Lee SH, Jang J. Sol-Gel-Processed Y 2O 3 Multilevel Resistive Random-Access Memory Cells for Neural Networks. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2432. [PMID: 37686940 PMCID: PMC10490495 DOI: 10.3390/nano13172432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 08/17/2023] [Accepted: 08/24/2023] [Indexed: 09/10/2023]
Abstract
Yttrium oxide (Y2O3) resistive random-access memory (RRAM) devices were fabricated using the sol-gel process on indium tin oxide/glass substrates. These devices exhibited conventional bipolar RRAM characteristics without requiring a high-voltage forming process. The effect of current compliance on the Y2O3 RRAM devices was investigated, and the results revealed that the resistance values gradually decreased with increasing set current compliance values. By regulating these values, the formation of pure Ag conductive filament could be restricted. The dominant oxygen ion diffusion and migration within Y2O3 leads to the formation of oxygen vacancies and Ag metal-mixed conductive filaments between the two electrodes. The filament composition changes from pure Ag metal to Ag metal mixed with oxygen vacancies, which is crucial for realizing multilevel cell (MLC) switching. Consequently, intermediate resistance values were obtained, which were suitable for MLC switching. The fabricated Y2O3 RRAM devices could function as a MLC with a capacity of two bits in one cell, utilizing three low-resistance states and one common high-resistance state. The potential of the Y2O3 RRAM devices for neural networks was further explored through numerical simulations. Hardware neural networks based on the Y2O3 RRAM devices demonstrated effective digit image classification with a high accuracy rate of approximately 88%, comparable to the ideal software-based classification (~92%). This indicates that the proposed RRAM can be utilized as a memory component in practical neuromorphic systems.
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Affiliation(s)
- Taehun Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (T.L.); (H.-I.K.); (Y.C.); (S.L.); (W.-Y.L.); (J.-H.B.); (I.-M.K.)
| | - Hae-In Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (T.L.); (H.-I.K.); (Y.C.); (S.L.); (W.-Y.L.); (J.-H.B.); (I.-M.K.)
| | - Yoonjin Cho
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (T.L.); (H.-I.K.); (Y.C.); (S.L.); (W.-Y.L.); (J.-H.B.); (I.-M.K.)
| | - Sangwoo Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (T.L.); (H.-I.K.); (Y.C.); (S.L.); (W.-Y.L.); (J.-H.B.); (I.-M.K.)
| | - Won-Yong Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (T.L.); (H.-I.K.); (Y.C.); (S.L.); (W.-Y.L.); (J.-H.B.); (I.-M.K.)
- The Institute of Electronic Technology, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Jin-Hyuk Bae
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (T.L.); (H.-I.K.); (Y.C.); (S.L.); (W.-Y.L.); (J.-H.B.); (I.-M.K.)
| | - In-Man Kang
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (T.L.); (H.-I.K.); (Y.C.); (S.L.); (W.-Y.L.); (J.-H.B.); (I.-M.K.)
| | - Kwangeun Kim
- School of Electronics and Information Engineering, Korea Aerospace University, Goyang 10540, Republic of Korea;
| | - Sin-Hyung Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (T.L.); (H.-I.K.); (Y.C.); (S.L.); (W.-Y.L.); (J.-H.B.); (I.-M.K.)
| | - Jaewon Jang
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Republic of Korea; (T.L.); (H.-I.K.); (Y.C.); (S.L.); (W.-Y.L.); (J.-H.B.); (I.-M.K.)
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16
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Ahn W, Jeong HB, Oh J, Hong W, Cha JH, Jeong HY, Choi SY. A Highly Reliable Molybdenum Disulfide-Based Synaptic Memristor Using a Copper Migration-Controlled Structure. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2300223. [PMID: 37093184 DOI: 10.1002/smll.202300223] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/13/2023] [Indexed: 05/03/2023]
Abstract
Memristors are drawing attention as neuromorphic hardware components because of their non-volatility and analog programmability. In particular, electrochemical metallization (ECM) memristors are extensively researched because of their linear conductance controllability. Two-dimensional materials as switching medium of ECM memristors give advantages of fast speed, low power consumption, and high switching uniformity. However, the multistate retention in the switching conductance range for the long-term reliable neuromorphic system has not been achieved using two-dimensional materials-based ECM memristors. In this study, the copper migration-controlled ECM memristor showing excellent multistate retention characteristics in the switching conductance range using molybdenum disulfide (MoS2 ) and aluminum oxide (Al2 O3 ) is proposed. The fabricated device exhibits gradual resistive switching with low switching voltage (<0.5 V), uniform switching (σ/µ ∼ 0.07), and a wide switching range (>12). Importantly, excellent reliabilities with robustness to cycling stress and retention over 104 s for more than 5-bit states in the switching conductance range are achieved. Moreover, the contribution of the Al2 O3 layer to the retention characteristic is investigated through filament morphology observation using transmission electron microscopy (TEM) and copper migration component analysis. This study provides a practical approach to developing highly reliable memristors with exceptional switching performance.
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Affiliation(s)
- Wonbae Ahn
- Graphene/2D Materials Research Center, School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Han Beom Jeong
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Jungyeop Oh
- Graphene/2D Materials Research Center, School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Woonggi Hong
- Convergence Semiconductor Research Center, School of Electronics and Electrical Engineering, Dankook University, 152 Jukjeon-ro, Suji-gu, Yongin-si, Gyeonggi-do 16890, Republic of Korea
| | - Jun-Hwe Cha
- Graphene/2D Materials Research Center, School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Hu Young Jeong
- Graduate School of Semiconductor Materials and Devices Engineering, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 44919, Republic of Korea
| | - Sung-Yool Choi
- Graphene/2D Materials Research Center, School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea
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17
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Won UY, An Vu Q, Park SB, Park MH, Dam Do V, Park HJ, Yang H, Lee YH, Yu WJ. Multi-neuron connection using multi-terminal floating-gate memristor for unsupervised learning. Nat Commun 2023; 14:3070. [PMID: 37244897 DOI: 10.1038/s41467-023-38667-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 05/10/2023] [Indexed: 05/29/2023] Open
Abstract
Multi-terminal memristor and memtransistor (MT-MEMs) has successfully performed complex functions of heterosynaptic plasticity in synapse. However, theses MT-MEMs lack the ability to emulate membrane potential of neuron in multiple neuronal connections. Here, we demonstrate multi-neuron connection using a multi-terminal floating-gate memristor (MT-FGMEM). The variable Fermi level (EF) in graphene allows charging and discharging of MT-FGMEM using horizontally distant multiple electrodes. Our MT-FGMEM demonstrates high on/off ratio over 105 at 1000 s retention about ~10,000 times higher than other MT-MEMs. The linear behavior between current (ID) and floating gate potential (VFG) in triode region of MT-FGMEM allows for accurate spike integration at the neuron membrane. The MT-FGMEM fully mimics the temporal and spatial summation of multi-neuron connections based on leaky-integrate-and-fire (LIF) functionality. Our artificial neuron (150 pJ) significantly reduces the energy consumption by 100,000 times compared to conventional neurons based on silicon integrated circuits (11.7 μJ). By integrating neurons and synapses using MT-FGMEMs, a spiking neurosynaptic training and classification of directional lines functioned in visual area one (V1) is successfully emulated based on neuron's LIF and synapse's spike-timing-dependent plasticity (STDP) functions. Simulation of unsupervised learning based on our artificial neuron and synapse achieves a learning accuracy of 83.08% on the unlabeled MNIST handwritten dataset.
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Affiliation(s)
- Ui Yeon Won
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, South Korea
- Hyundai motors group, Electronic Devices research Team, Uiwang, 16082, South Korea
| | - Quoc An Vu
- IBS Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Sung Bum Park
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Mi Hyang Park
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Van Dam Do
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Hyun Jun Park
- Display R&D Group, Mobile Communication Business, Samsung Electronics, Suwon, 16677, South Korea
| | - Heejun Yang
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, 34141, South Korea
| | - Young Hee Lee
- IBS Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon, 16419, South Korea.
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, South Korea.
| | - Woo Jong Yu
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, South Korea.
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18
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Tominov RV, Vakulov ZE, Avilov VI, Shikhovtsov IA, Varganov VI, Kazantsev VB, Gupta LR, Prakash C, Smirnov VA. Approaches for Memristive Structures Using Scratching Probe Nanolithography: Towards Neuromorphic Applications. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13101583. [PMID: 37242000 DOI: 10.3390/nano13101583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/28/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023]
Abstract
This paper proposes two different approaches to studying resistive switching of oxide thin films using scratching probe nanolithography of atomic force microscopy (AFM). These approaches allow us to assess the effects of memristor size and top-contact thickness on resistive switching. For that purpose, we investigated scratching probe nanolithography regimes using the Taguchi method, which is known as a reliable method for improving the reliability of the result. The AFM parameters, including normal load, scratch distance, probe speed, and probe direction, are optimized on the photoresist thin film by the Taguchi method. As a result, the pinholes with diameter ranged from 25.4 ± 2.2 nm to 85.1 ± 6.3 nm, and the groove array with a depth of 40.5 ± 3.7 nm and a roughness at the bottom of less than a few nanometers was formed. Then, based on the Si/TiN/ZnO/photoresist structures, we fabricated and investigated memristors with different spot sizes and TiN top contact thickness. As a result, the HRS/LRS ratio, USET, and ILRS are well controlled for a memristor size from 27 nm to 83 nm and ranged from ~8 to ~128, from 1.4 ± 0.1 V to 1.8 ± 0.2 V, and from (1.7 ± 0.2) × 10-10 A to (4.2 ± 0.6) × 10-9 A, respectively. Furthermore, the HRS/LRS ratio and USET are well controlled at a TiN top contact thickness from 8.3 ± 1.1 nm to 32.4 ± 4.2 nm and ranged from ~22 to ~188 and from 1.15 ± 0.05 V to 1.62 ± 0.06 V, respectively. The results can be used in the engineering and manufacturing of memristive structures for neuromorphic applications of brain-inspired artificial intelligence systems.
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Affiliation(s)
- Roman V Tominov
- Research Laboratory Neuroelectronics and Memristive Nanomaterials (NEUROMENA Lab), Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia
- Department of Radioelectronics and Nanoelectronics, Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia
| | - Zakhar E Vakulov
- Research Laboratory Neuroelectronics and Memristive Nanomaterials (NEUROMENA Lab), Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia
| | - Vadim I Avilov
- Research Laboratory Neuroelectronics and Memristive Nanomaterials (NEUROMENA Lab), Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia
| | - Ivan A Shikhovtsov
- Research Laboratory Neuroelectronics and Memristive Nanomaterials (NEUROMENA Lab), Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia
| | - Vadim I Varganov
- Research Laboratory Neuroelectronics and Memristive Nanomaterials (NEUROMENA Lab), Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia
| | - Victor B Kazantsev
- Research Laboratory Neuroelectronics and Memristive Nanomaterials (NEUROMENA Lab), Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia
- Institute of Biology and Biomedicine, National Research Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod 603950, Russia
| | - Lovi Raj Gupta
- Research Laboratory Neuroelectronics and Memristive Nanomaterials (NEUROMENA Lab), Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia
- Division of Research and Development, Lovely Professional University, Phagwara 144411, Panjab, India
| | - Chander Prakash
- Research Laboratory Neuroelectronics and Memristive Nanomaterials (NEUROMENA Lab), Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia
- School of Mechanical Engineering, Lovely Professional University, Phagwara 144411, Panjab, India
| | - Vladimir A Smirnov
- Research Laboratory Neuroelectronics and Memristive Nanomaterials (NEUROMENA Lab), Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia
- Department of Radioelectronics and Nanoelectronics, Institute of Nanotechnologies, Electronics and Electronic Equipment Engineering, Southern Federal University, Taganrog 347922, Russia
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19
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Zhang ZC, Chen XD, Lu TB. Recent progress in neuromorphic and memory devices based on graphdiyne. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2023; 24:2196240. [PMID: 37090847 PMCID: PMC10116926 DOI: 10.1080/14686996.2023.2196240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/20/2023] [Accepted: 03/24/2023] [Indexed: 05/03/2023]
Abstract
Graphdiyne (GDY) is an emerging two-dimensional carbon allotrope featuring a direct bandgap and fascinating physical and chemical properties, and it has demonstrated its promising potential in applications of catalysis, energy conversion and storage, electrical/optoelectronic devices, etc. In particular, the recent breakthrough in the synthesis of large-area, high-quality and ultrathin GDY films provides a feasible approach to developing high-performance electrical devices based on GDY. Recently, various GDY-based electrical and optoelectronic devices including multibit optoelectronic memories, ultrafast nonvolatile memories, artificial synapses and memristors have been proposed, in which GDY plays a crucial role. It is essential to summarize the recent breakthrough of GDY in device applications as a guidance, especially considering that the existing GDY-related reviews mainly focus on the applications in catalysis and energy-related fields. Herein, we review GDY-based novel memory and neuromorphic devices and their applications in neuromorphic computing and artificial visual systems. This review will provide an insight into the design and preparation of GDY-based devices and broaden the application fields of GDY.
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Affiliation(s)
- Zhi-Cheng Zhang
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Tianjin, China
| | - Xu-Dong Chen
- The Key Laboratory of Weak Light Nonlinear Photonics, Ministry of Education, School of Physics, Nankai University, Tianjin, China
- MOE International Joint Laboratory of Materials Microstructure, Institute for New Energy Materials and Low Carbon Technologies, School of Material Science and Engineering, Tianjin University of Technology, Tianjin, China
| | - Tong-Bu Lu
- MOE International Joint Laboratory of Materials Microstructure, Institute for New Energy Materials and Low Carbon Technologies, School of Material Science and Engineering, Tianjin University of Technology, Tianjin, China
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20
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Sharma D, Rao D, Saha B. A photonic artificial synapse with a reversible multifaceted photochromic compound. NANOSCALE HORIZONS 2023; 8:543-549. [PMID: 36852974 DOI: 10.1039/d2nh00532h] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Modern computational technology based on the von Neumann architecture physically partitions memory and the central processing unit, resulting in fundamental speed limitations and high energy consumption. On the other hand, the human brain is an extraordinary multifunctional organ composed of more than a billion neurons capable of simultaneously thinking, processing, and storing information. Neurons are interconnected with synapses that control information flow from pre-synaptic-to-post-synaptic neurons. Therefore, emulating synaptic functionalities and developing neuromorphic computational architecture has recently attracted much interest. Due to their high-speed, large bandwidth, and no interconnect-related power loss, photonic (all-optical) synapses can overcome the existing hurdles with electronic synapses. Here, we show an artificial photonic synapse by utilizing the well-established reversible, high-contrast photochromic organic compound, spiropyran, stimulated by optical pulses. Optical transmission of spiropyran significantly changes during spiropyran-merocyanine isomerization driven by UV-visible optical pulses. Such changes are equivalent to the biological synapses' inhibitory and excitatory synaptic actions. The slow relaxation to the initial state is considered as synaptic plasticity responsible for learning and memory formation. Short-term memory (STM), long-term memory (LTM), and transition from the STM to the LTM are demonstrated in all-optical synapses by modulating the stimuli's strength. The solvatochromic properties of spiropyran are further utilized to augment memory in synapses. Our work shows that photochromic organic compounds are excellent hosts for artificial photonic synapses and can be implemented in neuromorphic applications.
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Affiliation(s)
- Deeksha Sharma
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India.
- International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
| | - Dheemahi Rao
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India.
- International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
| | - Bivas Saha
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India.
- International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
- School of Advanced Materials (SAMat), Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
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21
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Shi J, Kang S, Feng J, Fan J, Xue S, Cai G, Zhao JS. Evaluating charge-type of polyelectrolyte as dielectric layer in memristor and synapse emulation. NANOSCALE HORIZONS 2023; 8:509-515. [PMID: 36757200 DOI: 10.1039/d2nh00524g] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Based on credible advantages, organic materials have received more and more attention in memristor and synapse emulation. In particular, an implementation of the ionic pathway as a dielectric layer is essential for organic materials used as building blocks of memristor and artificial synaptic devices. Herein, we describe an evaluation of the use of positive and negative polyelectrolytes as dielectric layers for a memristor with calcium ion (Ca2+) doping. The device based on a negative polyelectrolyte shows the potential to obtain an excellent resistive switching performance and synapse functionality, especially in the transformation behaviours from short-term plasticity (STP) to long-term plasticity (LTP) in both the potentiation and depression processes, which were comparable to the perfomrmance obtained with a positive polyelectrolyte. The mechanism of electrical resistance transition and synaptic function can be attributed to the migration of the doped Ca2+ and the ionic functional groups of polyelectrolyte, which result in the formation and vanishing filament-like Ca2+ flux.
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Affiliation(s)
- Jingzhou Shi
- Tianjin Key Laboratory of Film Electronic & Communication Devices, School of Integrated Circuit Science and Engineering, Tianjin University of Technology, No. 391, Binshui Xidao, Xiqing District, Tianjin, 300384, PR China.
| | - Shaohui Kang
- Tianjin Key Laboratory of Film Electronic & Communication Devices, School of Integrated Circuit Science and Engineering, Tianjin University of Technology, No. 391, Binshui Xidao, Xiqing District, Tianjin, 300384, PR China.
| | - Jiang Feng
- Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Department of Applied Chemistry, Tianjin University of Technology, No. 391, Binshui Xidao, Xiqing District, Tianjin, 300384, PR China.
| | - Jiaming Fan
- Tianjin Key Laboratory of Film Electronic & Communication Devices, School of Integrated Circuit Science and Engineering, Tianjin University of Technology, No. 391, Binshui Xidao, Xiqing District, Tianjin, 300384, PR China.
| | - Song Xue
- Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Department of Applied Chemistry, Tianjin University of Technology, No. 391, Binshui Xidao, Xiqing District, Tianjin, 300384, PR China.
| | - Gangri Cai
- Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, Department of Applied Chemistry, Tianjin University of Technology, No. 391, Binshui Xidao, Xiqing District, Tianjin, 300384, PR China.
| | - Jin Shi Zhao
- Tianjin Key Laboratory of Film Electronic & Communication Devices, School of Integrated Circuit Science and Engineering, Tianjin University of Technology, No. 391, Binshui Xidao, Xiqing District, Tianjin, 300384, PR China.
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22
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Jang YH, Han J, Kim J, Kim W, Woo KS, Kim J, Hwang CS. Graph Analysis with Multifunctional Self-Rectifying Memristive Crossbar Array. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2209503. [PMID: 36495559 DOI: 10.1002/adma.202209503] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Many big data have interconnected and dynamic graph structures growing over time. Analyzing these graphical data requires the hidden relationship between the nodes in the graphs to be identified, which has conventionally been achieved by finding the effective similarity. However, graphs are generally non-Euclidean, which does not allow finding it. In this study, the non-Euclidean graphs are mapped to a specific crossbar array (CBA) composed of self-rectifying memristors and metal cells at the diagonal positions. The sneak current, an intrinsic physical property in the CBA, allows for the identification of the similarity function. The sneak-current-based similarity function indicates the distance between the nodes, which can be used to predict the probability that unconnected nodes will be connected in the future, connectivity between communities, and neural connections in a brain. When all bit lines of the CBA are connected to the ground, the sneak current is suppressed, and the CBA can be used to search for adjacent nodes. This work demonstrates the physical calculation methods applied to various graphical problems using the CBA composed of the self-rectifying memristor based on the HfO2 switching layer. Moreover, such applications suffer less from the memristors' inherent issues related to their stochastic nature.
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Affiliation(s)
- Yoon Ho Jang
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Janguk Han
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jihun Kim
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Woohyun Kim
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Kyung Seok Woo
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jaehyun Kim
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
| | - Cheol Seong Hwang
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
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23
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Wang S, Li Y, Wang D, Zhang W, Chen X, Dong D, Wang S, Zhang X, Lin P, Gallicchio C, Xu X, Liu Q, Cheng KT, Wang Z, Shang D, Liu M. Echo state graph neural networks with analogue random resistive memory arrays. NAT MACH INTELL 2023. [DOI: 10.1038/s42256-023-00609-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
AbstractRecent years have witnessed a surge of interest in learning representations of graph-structured data, with applications from social networks to drug discovery. However, graph neural networks, the machine learning models for handling graph-structured data, face significant challenges when running on conventional digital hardware, including the slowdown of Moore’s law due to transistor scaling limits and the von Neumann bottleneck incurred by physically separated memory and processing units, as well as a high training cost. Here we present a hardware–software co-design to address these challenges, by designing an echo state graph neural network based on random resistive memory arrays, which are built from low-cost, nanoscale and stackable resistors for efficient in-memory computing. This approach leverages the intrinsic stochasticity of dielectric breakdown in resistive switching to implement random projections in hardware for an echo state network that effectively minimizes the training complexity thanks to its fixed and random weights. The system demonstrates state-of-the-art performance on both graph classification using the MUTAG and COLLAB datasets and node classification using the CORA dataset, achieving 2.16×, 35.42× and 40.37× improvements in energy efficiency for a projected random resistive memory-based hybrid analogue–digital system over a state-of-the-art graphics processing unit and 99.35%, 99.99% and 91.40% reductions of backward pass complexity compared with conventional graph learning. The results point to a promising direction for next-generation artificial intelligence systems for graph learning.
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24
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Kim HI, Lee T, Lee WY, Kim K, Bae JH, Kang IM, Lee SH, Kim K, Jang J. Improved Environment Stability of Y 2O 3 RRAM Devices with Au Passivated Ag Top Electrodes. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6859. [PMID: 36234198 PMCID: PMC9572085 DOI: 10.3390/ma15196859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 09/28/2022] [Accepted: 09/28/2022] [Indexed: 06/16/2023]
Abstract
In this study, we fabricated sol-gel-processed Y2O3-based resistive random-access memory (RRAM) devices. The fabricated Y2O3 RRAM devices exhibited conventional bipolar RRAM device characteristics and did not require the forming process. The long-term stability of the RRAM devices was investigated. The Y2O3 RRAM devices with a 20 nm thick Ag top electrode showed an increase in the low resistance state (LRS) and high resistance state (HRS) and a decrease in the HRS/LRS ratio after 30 days owing to oxidation and corrosion of the Ag electrodes. However, Y2O3 RRAM devices with inert Au-passivated Ag electrodes showed a constant RRAM device performance after 30 days. The 150 nm-thick Au passivation layer successfully suppressed the oxidation and corrosion of the Ag electrode by minimizing the chance of contact between water or oxygen molecules and Ag electrodes. The Au/Ag/Y2O3/ITO RRAM devices exhibited more than 300 switching cycles with a decent resistive window (>103). They maintained constant LRS and HRS resistances for up to 104 s, without significant degradation of nonvolatile memory properties for 30 days while stored in air.
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Affiliation(s)
- Hae-In Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea
| | - Taehun Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea
| | - Won-Yong Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea
| | - Kyoungdu Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea
| | - Jin-Hyuk Bae
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea
- School of Electronics Engineering, Kyungpook National University, Daegu 41566, Korea
| | - In-Man Kang
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea
- School of Electronics Engineering, Kyungpook National University, Daegu 41566, Korea
| | - Sin-Hyung Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea
- School of Electronics Engineering, Kyungpook National University, Daegu 41566, Korea
| | - Kwangeun Kim
- School of Electronics and Information Engineering, Korea Aerospace University, Goyang 10540, Korea
| | - Jaewon Jang
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea
- School of Electronics Engineering, Kyungpook National University, Daegu 41566, Korea
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25
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Woo KS, Kim J, Han J, Kim W, Jang YH, Hwang CS. Probabilistic computing using Cu 0.1Te 0.9/HfO 2/Pt diffusive memristors. Nat Commun 2022; 13:5762. [PMID: 36180426 PMCID: PMC9525628 DOI: 10.1038/s41467-022-33455-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 09/19/2022] [Indexed: 11/17/2022] Open
Abstract
A computing scheme that can solve complex tasks is necessary as the big data field proliferates. Probabilistic computing (p-computing) paves the way to efficiently handle problems based on stochastic units called probabilistic bits (p-bits). This study proposes p-computing based on the threshold switching (TS) behavior of a Cu0.1Te0.9/HfO2/Pt (CTHP) diffusive memristor. The theoretical background of the p-computing resembling the Hopfield network structure is introduced to explain the p-computing system. P-bits are realized by the stochastic TS behavior of CTHP diffusive memristors, and they are connected to form the p-computing network. The memristor-based p-bit is likely to be ‘0’ and ‘1’, of which probability is controlled by an input voltage. The memristor-based p-computing enables all 16 Boolean logic operations in both forward and inverted operations, showing the possibility of expanding its uses for complex operations, such as full adder and factorization. Designing a computing scheme to solve complex tasks as the big data field proliferates remains a challenge. Here, the authors present a probabilistic bit generation hardware built using the random nature of CuxTe1−x/HfO2/Pt memristors capable of performing logic gates with invertible mode, showing the expandability to complex logic circuits.
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Affiliation(s)
- Kyung Seok Woo
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National University, Gwanak-ro 1, Daehag-dong, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Jaehyun Kim
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National University, Gwanak-ro 1, Daehag-dong, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Janguk Han
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National University, Gwanak-ro 1, Daehag-dong, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Woohyun Kim
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National University, Gwanak-ro 1, Daehag-dong, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Yoon Ho Jang
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National University, Gwanak-ro 1, Daehag-dong, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Cheol Seong Hwang
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National University, Gwanak-ro 1, Daehag-dong, Gwanak-gu, Seoul, 08826, Republic of Korea.
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26
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Han MJ, Kim M, Tsukruk VV. Multivalued Logic for Optical Computing with Photonically Enabled Chiral Bio-organic Structures. ACS NANO 2022; 16:13684-13694. [PMID: 35882006 DOI: 10.1021/acsnano.2c04182] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Photonic bio-organic multiphase structures are suggested here for integrated thin-film electronic nets with multilevel logic elements for multilevel computing via a reconfigurable photonic bandgap of chiral biomaterials. Herein, inspired by an artificial intelligence system with efficient information integration and computing capability, the photonically active dielectric layer of chiral nematic cellulose nanocrystals is combined with printed-in p- and n-type organic semiconductors as a bifunctional logical element. These adaptive logic elements are capable of triggering tailored quantized electrical output signals under light with different photon energy and at the different photonic bandgaps of the active dielectric layer. The bifunctional structures enable complex memory behavior upon repetitive changes of photonic bandgap (controlled by expansion/contraction of chiral nematic pitch) and photon energy (controlled by light absorption wavelength of complementary organic semiconductor layers), exhibiting effectively a reconfigurable ternary logic response. This proof-of-concept bio-assisted multivalued logic structure facilitates an optical computing system for low-power optical information processing integrated with human-machine interfaces.
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Affiliation(s)
- Moon Jong Han
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Minkyu Kim
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Vladimir V Tsukruk
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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27
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Park J, Seong D, Park YJ, Park SH, Jung H, Kim Y, Baac HW, Shin M, Lee S, Lee M, Son D. Reversible electrical percolation in a stretchable and self-healable silver-gradient nanocomposite bilayer. Nat Commun 2022; 13:5233. [PMID: 36064549 PMCID: PMC9445036 DOI: 10.1038/s41467-022-32966-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 08/25/2022] [Indexed: 11/09/2022] Open
Abstract
The reversibly stable formation and rupture processes of electrical percolative pathways in organic and inorganic insulating materials are essential prerequisites for operating non-volatile resistive memory devices. However, such resistive switching has not yet been reported for dynamically cross-linked polymers capable of intrinsic stretchability and self-healing. This is attributable to the uncontrollable interplay between the conducting filler and the polymer. Herein, we present the development of the self-healing, stretchable, and reconfigurable resistive random-access memory. The device was fabricated via the self-assembly of a silver-gradient nanocomposite bilayer which is capable of easily forming the metal-insulator-metal structure. To realize stable resistive switching in dynamic molecular networks, our device features the following properties: i) self-reconstruction of nanoscale conducting fillers in dynamic hydrogen bonding for self-healing and reconfiguration and ii) stronger interaction among the conducting fillers than with polymers for the formation of robust percolation paths. Based on these unique features, we successfully demonstrated stable data storage of cardiac signals, damage-reliable memory triggering system using a triboelectric energy-harvesting device, and touch sensing via pressure-induced resistive switching.
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Affiliation(s)
- Jinhong Park
- The Institute for Basic Science, Inha University, Incheon, 22212, Republic of Korea.,Department of Physics, Inha University, Incheon, 22212, Republic of Korea
| | - Duhwan Seong
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea.,Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea
| | - Yong Jun Park
- Department of Physics, Inha University, Incheon, 22212, Republic of Korea
| | - Sang Hyeok Park
- Department of Physics, Inha University, Incheon, 22212, Republic of Korea
| | - Hyunjin Jung
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea.,Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea
| | - Yewon Kim
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea.,Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea
| | - Hyoung Won Baac
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Mikyung Shin
- Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea.,Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Seunghyun Lee
- Department of Electronic Engineering, Kyunghee University, Yongin, 17104, Republic of Korea
| | - Minbaek Lee
- The Institute for Basic Science, Inha University, Incheon, 22212, Republic of Korea. .,Department of Physics, Inha University, Incheon, 22212, Republic of Korea.
| | - Donghee Son
- Department of Electrical and Computer Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea. .,Center for Neuroscience Imaging Research, Institute for Basic Science (IBS), Suwon, 16419, Republic of Korea. .,Department of Superintelligence Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
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28
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Wang C, Xu X, Pi X, Butala MD, Huang W, Yin L, Peng W, Ali M, Bodepudi SC, Qiao X, Xu Y, Sun W, Yang D. Neuromorphic device based on silicon nanosheets. Nat Commun 2022; 13:5216. [PMID: 36064545 PMCID: PMC9445003 DOI: 10.1038/s41467-022-32884-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 08/22/2022] [Indexed: 11/09/2022] Open
Abstract
Silicon is vital for its high abundance, vast production, and perfect compatibility with the well-established CMOS processing industry. Recently, artificially stacked layered 2D structures have gained tremendous attention via fine-tuning properties for electronic devices. This article presents neuromorphic devices based on silicon nanosheets that are chemically exfoliated and surface-modified, enabling self-assembly into hierarchical stacking structures. The device functionality can be switched between a unipolar memristor and a feasibly reset-able synaptic device. The memory function of the device is based on the charge storage in the partially oxidized SiNS stacks followed by the discharge activated by the electric field at the Au-Si Schottky interface, as verified in both experimental and theoretical means. This work further inspired elegant neuromorphic computation models for digit recognition and noise filtration. Ultimately, it brings silicon - the most established semiconductor - back to the forefront for next-generation computations.
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Affiliation(s)
- Chenhao Wang
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China
| | - Xinyi Xu
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, 310027, Hangzhou, PR China
- State Key Laboratory of Silicon Materials & School of Micro-Nanoelectronics, Zhejiang University, 310027, Hangzhou, PR China
- College of Information Science and Electronics Engineering, Zhejiang University, 310027, Hangzhou, PR China
- ZJU-UIUC Institute (ZJUI), Zhejiang University, 314400, Jiaxing, PR China
| | - Xiaodong Pi
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, 310027, Hangzhou, PR China
| | - Mark D Butala
- ZJU-UIUC Institute (ZJUI), Zhejiang University, 314400, Jiaxing, PR China
| | - Wen Huang
- New Energy Technology Engineering Laboratory of Jiangsu Provence & School of Science, Nanjing University of Posts and Telecommunications, 210023, Nanjing, PR China
| | - Lei Yin
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China
| | - Wenbing Peng
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China
| | - Munir Ali
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, 310027, Hangzhou, PR China
- State Key Laboratory of Silicon Materials & School of Micro-Nanoelectronics, Zhejiang University, 310027, Hangzhou, PR China
| | - Srikrishna Chanakya Bodepudi
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, 310027, Hangzhou, PR China
- State Key Laboratory of Silicon Materials & School of Micro-Nanoelectronics, Zhejiang University, 310027, Hangzhou, PR China
| | - Xvsheng Qiao
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China
| | - Yang Xu
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, 310027, Hangzhou, PR China.
- State Key Laboratory of Silicon Materials & School of Micro-Nanoelectronics, Zhejiang University, 310027, Hangzhou, PR China.
- College of Information Science and Electronics Engineering, Zhejiang University, 310027, Hangzhou, PR China.
- ZJU-UIUC Institute (ZJUI), Zhejiang University, 314400, Jiaxing, PR China.
| | - Wei Sun
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China.
| | - Deren Yang
- State Key Laboratory of Silicon Materials & School of Materials Science and Engineering, Zhejiang University, 310027, Hangzhou, PR China.
- ZJU-Hangzhou Global Scientific and Technological Innovation Centre, 310027, Hangzhou, PR China.
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29
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Liu H, Dong Y, Galib M, Cai Z, Stan L, Zhang L, Suwardi A, Wu J, Cao J, Tan CKI, Sankaranarayanan SKRS, Narayanan B, Zhou H, Fong DD. Controlled Formation of Conduction Channels in Memristive Devices Observed by X-ray Multimodal Imaging. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2203209. [PMID: 35796130 DOI: 10.1002/adma.202203209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 06/29/2022] [Indexed: 06/15/2023]
Abstract
Neuromorphic computing provides a means for achieving faster and more energy efficient computations than conventional digital computers for artificial intelligence (AI). However, its current accuracy is generally less than the dominant software-based AI. The key to improving accuracy is to reduce the intrinsic randomness of memristive devices, emulating synapses in the brain for neuromorphic computing. Here using a planar device as a model system, the controlled formation of conduction channels is achieved with high oxygen vacancy concentrations through the design of sharp protrusions in the electrode gap, as observed by X-ray multimodal imaging of both oxygen stoichiometry and crystallinity. Classical molecular dynamics simulations confirm that the controlled formation of conduction channels arises from confinement of the electric field, yielding a reproducible spatial distribution of oxygen vacancies across switching cycles. This work demonstrates an effective route to control the otherwise random electroforming process by electrode design, facilitating the development of more accurate memristive devices for neuromorphic computing.
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Affiliation(s)
- Huajun Liu
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Yongqi Dong
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Mirza Galib
- Department of Mechanical Engineering, University of Louisville, Louisville, KY, 40208, USA
| | - Zhonghou Cai
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Liliana Stan
- Center for Nanoscale Materials, Nanoscience and Technology Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Lei Zhang
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Ady Suwardi
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Jing Wu
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Jing Cao
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | - Chee Kiang Ivan Tan
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Singapore, 138634, Singapore
| | | | - Badri Narayanan
- Department of Mechanical Engineering, University of Louisville, Louisville, KY, 40208, USA
| | - Hua Zhou
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Dillon D Fong
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
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Enhanced Switching Reliability of Sol–Gel-Processed Y2O3 RRAM Devices Based on Y2O3 Surface Roughness-Induced Local Electric Field. MATERIALS 2022; 15:ma15051943. [PMID: 35269170 PMCID: PMC8911950 DOI: 10.3390/ma15051943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 02/17/2022] [Accepted: 03/02/2022] [Indexed: 12/01/2022]
Abstract
Sol–gel-processed Y2O3 films were used as active channel layers for resistive random access memory (RRAM) devices. The fabricated ITO/Y2O3/Ag RRAM devices exhibited the properties of conventional bipolar memory devices. A triethylamine stabilizer with a high vapor pressure and low surface tension was added to realize the local electric field area. During drying and high-temperature post-annealing processes, the large convective flow enhanced the surface elevation, and the increased –OH groups accelerated the hydrolysis reaction and aggregation. These phenomena afforded Y2O3 films with an uneven surface morphology and an increased surface roughness. The increased roughness of the Y2O3 films attributable to the triethylamine stabilizer enhanced the local electrical field, improved device reliability, and achieved successful repetition of the switching properties over an extended period.
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Kim HJ, Kim DW, Lee WY, Kim K, Lee SH, Bae JH, Kang IM, Kim K, Jang J. Flexible Sol-Gel-Processed Y 2O 3 RRAM Devices Obtained via UV/Ozone-Assisted Photochemical Annealing Process. MATERIALS 2022; 15:ma15051899. [PMID: 35269129 PMCID: PMC8912058 DOI: 10.3390/ma15051899] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 02/25/2022] [Accepted: 03/02/2022] [Indexed: 12/31/2022]
Abstract
Flexible indium tin oxide (ITO)/Y2O3/Ag resistive random access memory (RRAM) devices were successfully fabricated using a thermal-energy-free ultraviolet (UV)/ozone-assisted photochemical annealing process. Using the UV/ozone-assisted photochemical process, the organic residue can be eliminated, and thinner and smother Y2O3 films than those formed using other methods can be fabricated. The flexible UV/ozone-assisted photochemical annealing process-based ITO/Y2O3/Ag RRAM devices exhibited the properties of conventional bipolar RRAM without any forming process. Furthermore, the pure and amorphous-phase Y2O3 films formed via this process showed a decreased leakage current and an increased high-resistance status (HRS) compared with the films formed using other methods. Therefore, RRAM devices can be realized on plastic substrates using a thermal-energy-free UV/ozone-assisted photochemical annealing process. The fabricated devices exhibited a resistive window (ratio of HRS/low-resistance status (LRS)) of >104, with the HRS and LRS values remaining almost the same (i.e., limited deterioration occurred) for 104 s and up to 102 programming/erasing operation cycles.
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Affiliation(s)
- Hyeon-Joong Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea; (H.-J.K.); (D.-W.K.); (W.-Y.L.); (K.K.); (S.-H.L.); (J.-H.B.); (I.-M.K.)
| | - Do-Won Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea; (H.-J.K.); (D.-W.K.); (W.-Y.L.); (K.K.); (S.-H.L.); (J.-H.B.); (I.-M.K.)
| | - Won-Yong Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea; (H.-J.K.); (D.-W.K.); (W.-Y.L.); (K.K.); (S.-H.L.); (J.-H.B.); (I.-M.K.)
| | - Kyoungdu Kim
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea; (H.-J.K.); (D.-W.K.); (W.-Y.L.); (K.K.); (S.-H.L.); (J.-H.B.); (I.-M.K.)
| | - Sin-Hyung Lee
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea; (H.-J.K.); (D.-W.K.); (W.-Y.L.); (K.K.); (S.-H.L.); (J.-H.B.); (I.-M.K.)
- School of Electronics Engineering, Kyungpook National University, Daegu 41566, Korea
| | - Jin-Hyuk Bae
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea; (H.-J.K.); (D.-W.K.); (W.-Y.L.); (K.K.); (S.-H.L.); (J.-H.B.); (I.-M.K.)
- School of Electronics Engineering, Kyungpook National University, Daegu 41566, Korea
| | - In-Man Kang
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea; (H.-J.K.); (D.-W.K.); (W.-Y.L.); (K.K.); (S.-H.L.); (J.-H.B.); (I.-M.K.)
- School of Electronics Engineering, Kyungpook National University, Daegu 41566, Korea
| | - Kwangeun Kim
- School of Electronics and Information Engineering, Korea Aerospace University, Goyang 10540, Korea;
| | - Jaewon Jang
- School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea; (H.-J.K.); (D.-W.K.); (W.-Y.L.); (K.K.); (S.-H.L.); (J.-H.B.); (I.-M.K.)
- School of Electronics Engineering, Kyungpook National University, Daegu 41566, Korea
- Correspondence:
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Wang Z, Hong Q, Wang X. A Memristive Circuit Implementation of Eyes State Detection in Fatigue Driving Based on Biological Long Short-Term Memory Rule. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2021; 18:2218-2229. [PMID: 32086217 DOI: 10.1109/tcbb.2020.2974944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Biological long short-term memory (B-LSTM) can effectively help human process all kinds of received information. In this work, a memristive B-LSTM circuit which mimics a conversion from short-term memory to long-term memory is proposed. That is, the stronger the signal, the more profound the memory and the higher the output. On this basis, an image binarization circuit using adaptive row threshold algorithm is proposed. It can make the image remain a deep impression on the strong pixel information and effectively filter the relatively weak pixel information. In combination with the function of image binarization, a memristive circuit for eyes state detection is proposed by adding corresponding horizontal projection calculation, subtraction calculation and judgement open or closed eyes modules. The proposed circuit can detect whether there is a blink between two adjacent facial images, which uses the characteristics of memristor to detect the difference of horizontal projection between two images. Due to the use of memristor, the proposed circuit can realize in-memory computing, which fundamentally avoids the problem of storage wall and shorten the execution time. Finally, an expectation application in fatigue driving based on the proposed method is demonstrated, which indicates the practicability of the circuit design in this work.
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Zhang W, Wang Y, Ji X, Wu Y, Zhao R. ROA: A Rapid Learning Scheme for In-Situ Memristor Networks. Front Artif Intell 2021; 4:692065. [PMID: 34723173 PMCID: PMC8554302 DOI: 10.3389/frai.2021.692065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 09/10/2021] [Indexed: 11/13/2022] Open
Abstract
Memristors show great promise in neuromorphic computing owing to their high-density integration, fast computing and low-energy consumption. However, the non-ideal update of synaptic weight in memristor devices, including nonlinearity, asymmetry and device variation, still poses challenges to the in-situ learning of memristors, thereby limiting their broad applications. Although the existing offline learning schemes can avoid this problem by transferring the weight optimization process into cloud, it is difficult to adapt to unseen tasks and uncertain environments. Here, we propose a bi-level meta-learning scheme that can alleviate the non-ideal update problem, and achieve fast adaptation and high accuracy, named Rapid One-step Adaption (ROA). By introducing a special regularization constraint and a dynamic learning rate strategy for in-situ learning, the ROA method effectively combines offline pre-training and online rapid one-step adaption. Furthermore, we implemented it on memristor-based neural networks to solve few-shot learning tasks, proving its superiority over the pure offline and online schemes under noisy conditions. This method can solve in-situ learning in non-ideal memristor networks, providing potential applications of on-chip neuromorphic learning and edge computing.
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Affiliation(s)
| | | | | | | | - Rong Zhao
- Department of Precision Instrument, Center for Brain Inspired Computing Research, Beijing Innovation Center for Future Chip, Tsinghua University, Beijing, China
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Jang YH, Kim W, Kim J, Woo KS, Lee HJ, Jeon JW, Shim SK, Han J, Hwang CS. Time-varying data processing with nonvolatile memristor-based temporal kernel. Nat Commun 2021; 12:5727. [PMID: 34593800 PMCID: PMC8484437 DOI: 10.1038/s41467-021-25925-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 09/09/2021] [Indexed: 11/24/2022] Open
Abstract
Recent advances in physical reservoir computing, which is a type of temporal kernel, have made it possible to perform complicated timing-related tasks using a linear classifier. However, the fixed reservoir dynamics in previous studies have limited application fields. In this study, temporal kernel computing was implemented with a physical kernel that consisted of a W/HfO2/TiN memristor, a capacitor, and a resistor, in which the kernel dynamics could be arbitrarily controlled by changing the circuit parameters. After the capability of the temporal kernel to identify the static MNIST data was proven, the system was adopted to recognize the sequential data, ultrasound (malignancy of lesions) and electrocardiogram (arrhythmia), that had a significantly different time constant (10-7 vs. 1 s). The suggested system feasibly performed the tasks by simply varying the capacitance and resistance. These functionalities demonstrate the high adaptability of the present temporal kernel compared to the previous ones.
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Affiliation(s)
- Yoon Ho Jang
- Department of Materials Science and Engineering College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Inter-university Semiconductor Research Center, Seoul National University, Seoul, 08826, Republic of Korea
| | - Woohyun Kim
- Department of Materials Science and Engineering College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Inter-university Semiconductor Research Center, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jihun Kim
- Department of Materials Science and Engineering College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Inter-university Semiconductor Research Center, Seoul National University, Seoul, 08826, Republic of Korea
| | - Kyung Seok Woo
- Department of Materials Science and Engineering College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Inter-university Semiconductor Research Center, Seoul National University, Seoul, 08826, Republic of Korea
| | - Hyun Jae Lee
- Department of Materials Science and Engineering College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Inter-university Semiconductor Research Center, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jeong Woo Jeon
- Department of Materials Science and Engineering College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Inter-university Semiconductor Research Center, Seoul National University, Seoul, 08826, Republic of Korea
| | - Sung Keun Shim
- Department of Materials Science and Engineering College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Inter-university Semiconductor Research Center, Seoul National University, Seoul, 08826, Republic of Korea
| | - Janguk Han
- Department of Materials Science and Engineering College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Inter-university Semiconductor Research Center, Seoul National University, Seoul, 08826, Republic of Korea
| | - Cheol Seong Hwang
- Department of Materials Science and Engineering College of Engineering, Seoul National University, Seoul, 08826, Republic of Korea.
- Inter-university Semiconductor Research Center, Seoul National University, Seoul, 08826, Republic of Korea.
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35
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Wang R, Chen P, Hao D, Zhang J, Shi Q, Liu D, Li L, Xiong L, Zhou J, Huang J. Artificial Synapses Based on Lead-Free Perovskite Floating-Gate Organic Field-Effect Transistors for Supervised and Unsupervised Learning. ACS APPLIED MATERIALS & INTERFACES 2021; 13:43144-43154. [PMID: 34470204 DOI: 10.1021/acsami.1c08424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Synaptic devices are expected to overcome von Neumann's bottleneck and served as one of the foundations for future neuromorphic computing. Lead halide perovskites are considered as promising photoactive materials but limited by the toxicity of lead. Herein, lead-free perovskite CsBi3I10 is utilized as a photoactive material to fabricate organic synaptic transistors with a floating-gate structure for the first time. The devices can maintain the Ilight/Idark ratio of 103 for 4 h and have excellent stability within the 30 days test even without encapsulation. Synaptic functions are successfully simulated. Notably, by combining the decent charge transport property of the organic semiconductor and the excellent photoelectronic property of CsBi3I10, synaptic performance can be realized even with an operating voltage as low as -0.01 V, which is rare among floating-gate synaptic transistors. Furthermore, artificial neural networks are constructed. We propose a new method that can simulate the synaptic weight value in multiple digit form to achieve complete gradient descent. The image recognition test exhibits thrilling recognition accuracy for both supervised (91%) and unsupervised (81%) classifications. These results demonstrate the great potential of floating-gate organic synaptic transistors in neuromorphic computing.
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Affiliation(s)
- Ruizhi Wang
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 201804, P. R. China
| | - Pengyue Chen
- School of Electronic and Information Engineering, Tongji University, Shanghai 201804, P. R. China
| | - Dandan Hao
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 201804, P. R. China
| | - Junyao Zhang
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 201804, P. R. China
| | - Qianqian Shi
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 201804, P. R. China
| | - Dapeng Liu
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 201804, P. R. China
| | - Li Li
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 201804, P. R. China
| | - Lize Xiong
- Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital Affiliated to Tongji University, Shanghai 200434, P. R. China
| | - Junhe Zhou
- School of Electronic and Information Engineering, Tongji University, Shanghai 201804, P. R. China
| | - Jia Huang
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Shanghai Institute of Intelligent Science and Technology, Tongji University, Shanghai 201804, P. R. China
- Translational Research Institute of Brain and Brain-Like Intelligence, Shanghai Fourth People's Hospital Affiliated to Tongji University, Shanghai 200434, P. R. China
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Meyer T, Kressdorf B, Roddatis V, Hoffmann J, Jooss C, Seibt M. Phase Transitions in a Perovskite Thin Film Studied by Environmental In Situ Heating Nano-Beam Electron Diffraction. SMALL METHODS 2021; 5:e2100464. [PMID: 34928052 DOI: 10.1002/smtd.202100464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Indexed: 06/14/2023]
Abstract
The rich phase diagram of bulk Pr1-x Cax MnO3 resulting in a high tunability of physical properties gives rise to various studies related to fundamental research as well as prospective applications of the material. Importantly, as a consequence of strong correlation effects, electronic and lattice degrees of freedom are vigorously coupled. Hence, it is debatable whether such bulk phase diagrams can be transferred to inherently strained epitaxial thin films. In this paper, the structural orthorhombic to pseudo-cubic transition for x = 0.1 is studied in ion-beam sputtered thin films and differences to the respective bulk system are pointed out by employing in situ heating nano-beam electron diffraction to follow the temperature dependence of lattice constants. In addition, it is demonstrated that controlling the environment during heating, that is, preventing oxygen loss, is crucial in order to avoid irreversible structural changes, which is expected to be a general problem of compounds containing volatile elements under non-equilibrium conditions.
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Affiliation(s)
- Tobias Meyer
- 4th Institute of Physics - Solids and Nanostructures, University of Goettingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
| | - Birte Kressdorf
- Institute of Materials Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
| | - Vladimir Roddatis
- Institute of Materials Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
| | - Jörg Hoffmann
- Institute of Materials Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
| | - Christian Jooss
- Institute of Materials Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
| | - Michael Seibt
- 4th Institute of Physics - Solids and Nanostructures, University of Goettingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
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37
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Yan Y, Li JC, Chen YT, Wang XY, Cai GR, Park HW, Kim JH, Zhao JS, Hwang CS. Area-Type Electronic Bipolar Switching Al/TiO 1.7/TiO 2/Al Memory with Linear Potentiation and Depression Characteristics. ACS APPLIED MATERIALS & INTERFACES 2021; 13:39561-39572. [PMID: 34378371 DOI: 10.1021/acsami.1c09436] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In electronic bipolar resistive switching (eBRS), the electron trapping and detrapping at the defect sites within the switching layer, such as the highly defective TiO1.7 in this study, constitute the switching mechanism. It is an appealing candidate solution to the nonuniformity issue of resistive switching memory. However, TiO1.7-based eBRS has suffered from a lack of endurance and retention. In this study, a 7 nm-thick stoichiometric TiO2 layer is interposed between an Al bottom electrode and a 50 nm-thick TiO1.7 layer, which is in contact with an Al top electrode. Despite the minimal structural modification, improvements in the electrical performance were substantial. The off-to-on state resistance ratio of 20 and the resistance values could be retained up to 30 000 direct current sweep cycles and 106 alternating current pulse switching cycles. Data retention also significantly improves. Moreover, the device is electroforming-free and shows fully area-type switching characteristics. Such notable improvements are attributed to the favorable energy band structure of the Al/TiO1.7/TiO2/Al structure. The device shows almost linear potentiation and depression characteristics after the repeated pulse voltage applications, which significantly improves the accuracy of the neural network, the synapses of which are composed of the Al/TiO1.7/TiO2/Al memory cells.
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Affiliation(s)
- Yu Yan
- Tianjin Key Laboratory of Film Electronic & Communication Devices, School of Integrated Circuit Science and Engineering, Tianjin University of Technology, No. 391, Binshuixi Road, Xiqing District, Tianjin 300384, China
| | - Jia Cheng Li
- Tianjin Key Laboratory of Film Electronic & Communication Devices, School of Integrated Circuit Science and Engineering, Tianjin University of Technology, No. 391, Binshuixi Road, Xiqing District, Tianjin 300384, China
| | - Yu Ting Chen
- Tianjin Key Laboratory of Film Electronic & Communication Devices, School of Integrated Circuit Science and Engineering, Tianjin University of Technology, No. 391, Binshuixi Road, Xiqing District, Tianjin 300384, China
| | - Xiang Yu Wang
- Tianjin Key Laboratory of Film Electronic & Communication Devices, School of Integrated Circuit Science and Engineering, Tianjin University of Technology, No. 391, Binshuixi Road, Xiqing District, Tianjin 300384, China
| | - Gang Ri Cai
- Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry and Chemical Engineering, Tianjin University of Technology, No. 391, Binshuixi Road, Xiqing District, Tianjin 300384, China
| | - Hyeon Woo Park
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, Seoul National University, Gwanak-ro 1, Daehag-dong, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Ji Hun Kim
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, Seoul National University, Gwanak-ro 1, Daehag-dong, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Jin Shi Zhao
- Tianjin Key Laboratory of Film Electronic & Communication Devices, School of Integrated Circuit Science and Engineering, Tianjin University of Technology, No. 391, Binshuixi Road, Xiqing District, Tianjin 300384, China
| | - Cheol Seong Hwang
- Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, Seoul National University, Gwanak-ro 1, Daehag-dong, Gwanak-gu, Seoul 08826, Republic of Korea
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Beom K, Han J, Kim HM, Yoon TS. Wide range modulation of synaptic weight in thin-film transistors with hafnium oxide gate insulator and indium-zinc oxide channel layer for artificial synapse application. NANOSCALE 2021; 13:11370-11379. [PMID: 34160528 DOI: 10.1039/d1nr02911h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Wide range synaptic weight modulation with a tunable drain current was demonstrated in thin-film transistors (TFTs) with a hafnium oxide (HfO2-x) gate insulator and an indium-zinc oxide (IZO) channel layer for application to artificial synapses in neuromorphic systems. The drain current in these TFTs was reduced significantly by four orders of magnitude on application of a negative gate bias, then could be restored to its original value by applying a positive bias. The reduced drain current under negative biasing is interpreted as being caused by voltage-driven oxygen ion migration from the HfO2-x gate insulator to the IZO channel, which reduces the oxygen vacancy concentration in the IZO channel. In addition to emulating the analog-type potentiation and depression motions in artificial synapses, the tunable drain current presents paired-pulse facilitation and short-term and long-term plasticity behaviors. These wide-ranging and nonvolatile synaptic behaviors with tunable drain currents are indicative of the potential of the proposed TFTs for artificial synapse applications.
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Affiliation(s)
- Keonwon Beom
- School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ 85287, USA
| | - Jimin Han
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea.
| | - Hyun-Mi Kim
- Korea Electronics Technology Institute, Gyeonggi-do 13509, Republic of Korea
| | - Tae-Sik Yoon
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea.
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Bauers SR, Tellekamp MB, Roberts DM, Hammett B, Lany S, Ferguson AJ, Zakutayev A, Nanayakkara SU. Metal chalcogenides for neuromorphic computing: emerging materials and mechanisms. NANOTECHNOLOGY 2021; 32:372001. [PMID: 33882467 DOI: 10.1088/1361-6528/abfa51] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 04/21/2021] [Indexed: 06/12/2023]
Abstract
The approaching end of Moore's law scaling has significantly accelerated multiple fields of research including neuromorphic-, quantum-, and photonic computing, each of which possesses unique benefits unobtained through conventional binary computers. One of the most compelling arguments for neuromorphic computing systems is power consumption, noting that computations made in the human brain are approximately 106times more efficient than conventional CMOS logic. This review article focuses on the materials science and physical mechanisms found in metal chalcogenides that are currently being explored for use in neuromorphic applications. We begin by reviewing the key biological signal generation and transduction mechanisms within neuronal components of mammalian brains and subsequently compare with observed experimental measurements in chalcogenides. With robustness and energy efficiency in mind, we will focus on short-range mechanisms such as structural phase changes and correlated electron systems that can be driven by low-energy stimuli, such as temperature or electric field. We aim to highlight fundamental materials research and existing gaps that need to be overcome to enable further integration or advancement of metal chalcogenides for neuromorphic systems.
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Affiliation(s)
- Sage R Bauers
- Materials Science Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, United States of America
| | - M Brooks Tellekamp
- Materials Science Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, United States of America
| | - Dennice M Roberts
- Materials Science Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, United States of America
| | - Breanne Hammett
- Materials Science Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, United States of America
- Department of Chemistry, Colorado School of Mines, 1500 Illinois Avenue, Golden, CO 80401, United States of America
| | - Stephan Lany
- Materials Science Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, United States of America
| | - Andrew J Ferguson
- Chemistry and Nanoscience Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, United States of America
| | - Andriy Zakutayev
- Materials Science Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, United States of America
| | - Sanjini U Nanayakkara
- Materials Science Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, United States of America
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40
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Luo ZD, Yang MM, Liu Y, Alexe M. Emerging Opportunities for 2D Semiconductor/Ferroelectric Transistor-Structure Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005620. [PMID: 33577112 DOI: 10.1002/adma.202005620] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/26/2020] [Indexed: 06/12/2023]
Abstract
Semiconductor technology, which is rapidly evolving, is poised to enter a new era for which revolutionary innovations are needed to address fundamental limitations on material and working principle level. 2D semiconductors inherently holding novel properties at the atomic limit show great promise to tackle challenges imposed by traditional bulk semiconductor materials. Synergistic combination of 2D semiconductors with functional ferroelectrics further offers new working principles, and is expected to deliver massively enhanced device performance for existing complementary metal-oxide-semiconductor (CMOS) technologies and add unprecedented applications for next-generation electronics. Herein, recent demonstrations of novel device concepts based on 2D semiconductor/ferroelectric heterostructures are critically reviewed covering their working mechanisms, device construction, applications, and challenges. In particular, emerging opportunities of CMOS-process-compatible 2D semiconductor/ferroelectric transistor structure devices for the development of a rich variety of applications are discussed, including beyond-Boltzmann transistors, nonvolatile memories, neuromorphic devices, and reconfigurable nanodevices such as p-n homojunctions and self-powered photodetectors. It is concluded that 2D semiconductor/ferroelectric heterostructures, as an emergent heterogeneous platform, could drive many more exciting innovations for modern electronics, beyond the capability of ubiquitous silicon systems.
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Affiliation(s)
- Zheng-Dong Luo
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK
| | - Ming-Min Yang
- Center for Emergent Matter Science, RIKEN, Wako, Saitama, 351-0198, Japan
| | - Yang Liu
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Marin Alexe
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK
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41
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Curved neuromorphic image sensor array using a MoS 2-organic heterostructure inspired by the human visual recognition system. Nat Commun 2020; 11:5934. [PMID: 33230113 PMCID: PMC7683533 DOI: 10.1038/s41467-020-19806-6] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/27/2020] [Indexed: 12/22/2022] Open
Abstract
Conventional imaging and recognition systems require an extensive amount of data storage, pre-processing, and chip-to-chip communications as well as aberration-proof light focusing with multiple lenses for recognizing an object from massive optical inputs. This is because separate chips (i.e., flat image sensor array, memory device, and CPU) in conjunction with complicated optics should capture, store, and process massive image information independently. In contrast, human vision employs a highly efficient imaging and recognition process. Here, inspired by the human visual recognition system, we present a novel imaging device for efficient image acquisition and data pre-processing by conferring the neuromorphic data processing function on a curved image sensor array. The curved neuromorphic image sensor array is based on a heterostructure of MoS2 and poly(1,3,5-trimethyl-1,3,5-trivinyl cyclotrisiloxane). The curved neuromorphic image sensor array features photon-triggered synaptic plasticity owing to its quasi-linear time-dependent photocurrent generation and prolonged photocurrent decay, originated from charge trapping in the MoS2-organic vertical stack. The curved neuromorphic image sensor array integrated with a plano-convex lens derives a pre-processed image from a set of noisy optical inputs without redundant data storage, processing, and communications as well as without complex optics. The proposed imaging device can substantially improve efficiency of the image acquisition and recognition process, a step forward to the next generation machine vision. Designing efficient bio-inspired visual recognition system remains a challenge. Here the authors present a curved neuromorphic image sensor array based on a heterostructure of MoS2 and pV3D3 integrated with a plano-convex lens for efficient image acquisition and data pre-processing.
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42
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Lin CY, Chen J, Chen PH, Chang TC, Wu Y, Eshraghian JK, Moon J, Yoo S, Wang YH, Chen WC, Wang ZY, Huang HC, Li Y, Miao X, Lu WD, Sze SM. Adaptive Synaptic Memory via Lithium Ion Modulation in RRAM Devices. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e2003964. [PMID: 32996256 DOI: 10.1002/smll.202003964] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/12/2020] [Indexed: 06/11/2023]
Abstract
Biologically plausible computing systems require fine-grain tuning of analog synaptic characteristics. In this study, lithium-doped silicate resistive random access memory with a titanium nitride (TiN) electrode mimicking biological synapses is demonstrated. Biological plausibility of this RRAM device is thought to occur due to the low ionization energy of lithium ions, which enables controllable forming and filamentary retraction spontaneously or under an applied voltage. The TiN electrode can effectively store lithium ions, a principle widely adopted from battery construction, and allows state-dependent decay to be reliably achieved. As a result, this device offers multi-bit functionality and synaptic plasticity for simulating various strengths in neuronal connections. Both short-term memory and long-term memory are emulated across dynamical timescales. Spike-timing-dependent plasticity and paired-pulse facilitation are also demonstrated. These mechanisms are capable of self-pruning to generate efficient neural networks. Time-dependent resistance decay is observed for different conductance values, which mimics both biological and artificial memory pruning and conforms to the trend of the biological brain that prunes weak synaptic connections. By faithfully emulating learning rules that exist in human's higher cortical areas from STDP to synaptic pruning, the device has the capacity to drive forward the development of highly efficient neuromorphic computing systems.
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Affiliation(s)
- Chih-Yang Lin
- Department of Physics, National Sun Yat-sen University, No.70 Lien-hai Road, Kaohsiung, 80424, Taiwan
| | - Jia Chen
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, No.1037 Luoyu Road, Wuhan, 430074, China
| | - Po-Hsun Chen
- Department of Applied Science, R.O.C. Naval Academy, No.669 Junxiao Road, Kaohsiung, 81345, Taiwan
- Center for Nanoscience and Nanotechnology, National Sun Yat-sen University, No.70 Lien-hai Road, Kaohsiung, 80424, Taiwan
| | - Ting-Chang Chang
- Department of Physics, The Center of Crystal Research, National Sun Yat-sen University, No.70 Lien-hai Road, Kaohsiung, 80424, Taiwan
| | - Yuting Wu
- Electrical Engineering and Computer Science, University of Michigan, No.1301 Beal Avenue, Ann Arbor, Michigan, 48109-2122, USA
| | - Jason K Eshraghian
- Electrical Engineering and Computer Science, University of Michigan, No.1301 Beal Avenue, Ann Arbor, Michigan, 48109-2122, USA
| | - John Moon
- Electrical Engineering and Computer Science, University of Michigan, No.1301 Beal Avenue, Ann Arbor, Michigan, 48109-2122, USA
| | - Sangmin Yoo
- Electrical Engineering and Computer Science, University of Michigan, No.1301 Beal Avenue, Ann Arbor, Michigan, 48109-2122, USA
| | - Yu-Hsun Wang
- Department of Electronics Engineering and Institute of Electronics, National Chiao Tung University, No.1001 University Road, Hsinchu, 30010, Taiwan
| | - Wen-Chung Chen
- Department of Materials and Optoelectronic Science, National Sun Yat-sen University, No.70 Lien-hai Road, Kaohsiung, 80424, Taiwan
| | - Zhi-Yang Wang
- Department of Materials and Optoelectronic Science, National Sun Yat-sen University, No.70 Lien-hai Road, Kaohsiung, 80424, Taiwan
| | - Hui-Chun Huang
- Department of Materials and Optoelectronic Science, National Sun Yat-sen University, No.70 Lien-hai Road, Kaohsiung, 80424, Taiwan
| | - Yi Li
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, No.1037 Luoyu Road, Wuhan, 430074, China
| | - Xiangshui Miao
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, No.1037 Luoyu Road, Wuhan, 430074, China
| | - Wei D Lu
- Electrical Engineering and Computer Science, University of Michigan, No.1301 Beal Avenue, Ann Arbor, Michigan, 48109-2122, USA
| | - Simon M Sze
- Department of Electronics Engineering and Institute of Electronics, National Chiao Tung University, No.1001 University Road, Hsinchu, 30010, Taiwan
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Analogue pattern recognition with stochastic switching binary CMOS-integrated memristive devices. Sci Rep 2020; 10:14450. [PMID: 32879397 PMCID: PMC7467933 DOI: 10.1038/s41598-020-71334-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 08/14/2020] [Indexed: 11/29/2022] Open
Abstract
Biological neural networks outperform current computer technology in terms of power consumption and computing speed while performing associative tasks, such as pattern recognition. The analogue and massive parallel in-memory computing in biology differs strongly from conventional transistor electronics that rely on the von Neumann architecture. Therefore, novel bio-inspired computing architectures have been attracting a lot of attention in the field of neuromorphic computing. Here, memristive devices, which serve as non-volatile resistive memory, are employed to emulate the plastic behaviour of biological synapses. In particular, CMOS integrated resistive random access memory (RRAM) devices are promising candidates to extend conventional CMOS technology to neuromorphic systems. However, dealing with the inherent stochasticity of resistive switching can be challenging for network performance. In this work, the probabilistic switching is exploited to emulate stochastic plasticity with fully CMOS integrated binary RRAM devices. Two different RRAM technologies with different device variabilities are investigated in detail, and their potential applications in stochastic artificial neural networks (StochANNs) capable of solving MNIST pattern recognition tasks is examined. A mixed-signal implementation with hardware synapses and software neurons combined with numerical simulations shows that the proposed concept of stochastic computing is able to process analogue data with binary memory cells.
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44
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Memristive Logic Design of Multifunctional Spiking Neural Network with Unsupervised Learning. BIONANOSCIENCE 2020. [DOI: 10.1007/s12668-020-00778-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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45
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Cha JH, Yang SY, Oh J, Choi S, Park S, Jang BC, Ahn W, Choi SY. Conductive-bridging random-access memories for emerging neuromorphic computing. NANOSCALE 2020; 12:14339-14368. [PMID: 32373884 DOI: 10.1039/d0nr01671c] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
With the increasing utilisation of artificial intelligence, there is a renewed demand for the development of novel neuromorphic computing owing to the drawbacks of the existing computing paradigm based on the von Neumann architecture. Extensive studies have been performed on memristors as their electrical nature is similar to those of biological synapses and neurons. However, most hardware-based artificial neural networks (ANNs) have been developed with oxide-based memristors owing to their high compatibility with mature complementary metal-oxide-semiconductor (CMOS) processes. Considering the advantages of conductive-bridging random-access memories (CBRAMs), such as their high scalability, high on-off current with a wide dynamic range, and low off-current, over oxide-based memristors, extensive studies on CBRAMs are required. In this review, the basics of operation of CBRAMs are examined in detail, from the formation of metal nanoclusters to filament bridging. Additionally, state-of-the-art experimental demonstrations of CBRAM-based artificial synapses and neurons are presented. Finally, CBRAM-based ANNs are discussed, including deep neural networks and spiking neural networks, along with other emerging computing applications. This review is expected to pave the way toward further development of large-scale CBRAM array systems.
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Affiliation(s)
- Jun-Hwe Cha
- School of Electrical Engineering, Graphene/2D Materials Research Center, Center for Advanced Materials Discovery towards 3D Displays, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
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Abstract
Neuromorphic systems are currently experiencing a rapid upswing due to the fact that today's CMOS (complementary metal oxide silicon) based technologies are increasingly approaching their limits. In particular, for the area of machine learning, energy consumption of today's electronics is an important limitation, that also contributes toward the ever-increasing impact of digitalization on our climate. Thus, in order to better meet the special requirements of unconventional computing, new physical substrates for bio-inspired computing schemes are extensively exploited. The aim of this Guest Edited Collection is to provide a platform for interdisciplinary research along three main lines: memristive materials and devices, emulation of cellular learning (neurons and synapses), and unconventional computing and network schemes.
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47
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Ham S, Kang M, Jang S, Jang J, Choi S, Kim TW, Wang G. One-dimensional organic artificial multi-synapses enabling electronic textile neural network for wearable neuromorphic applications. SCIENCE ADVANCES 2020; 6:eaba1178. [PMID: 32937532 PMCID: PMC10662591 DOI: 10.1126/sciadv.aba1178] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 05/29/2020] [Indexed: 05/10/2023]
Abstract
One-dimensional (1D) devices are becoming the most desirable format for wearable electronic technology because they can be easily woven into electronic (e-) textile(s) with versatile functional units while maintaining their inherent features under mechanical stress. In this study, we designed 1D fiber-shaped multi-synapses comprising ferroelectric organic transistors fabricated on a 100-μm Ag wire and used them as multisynaptic channels in an e-textile neural network for wearable neuromorphic applications. The device mimics diverse synaptic functions with excellent reliability even under 6000 repeated input stimuli and mechanical bending stress. Various NOR-type textile arrays are formed simply by cross-pointing 1D synapses with Ag wires, where each output from individual synapse can be integrated and propagated without undesired leakage. Notably, the 1D multi-synapses achieved up to ~90 and ~70% recognition accuracy for MNIST and electrocardiogram patterns, respectively, even in a single-layer neural network, and almost maintained regardless of the bending conditions.
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Affiliation(s)
- Seonggil Ham
- KU-KIST Graduate School of Converging Science and Technology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Minji Kang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, 92 Chudong-ro, Bongdong-eup, Wanju-gun, Jeollabuk-do 55324, Republic of Korea
| | - Seonghoon Jang
- KU-KIST Graduate School of Converging Science and Technology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Jingon Jang
- KU-KIST Graduate School of Converging Science and Technology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Sanghyeon Choi
- KU-KIST Graduate School of Converging Science and Technology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Tae-Wook Kim
- Department of Flexible and Printable Electronics, Jeonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 54896, Republic of Korea.
| | - Gunuk Wang
- KU-KIST Graduate School of Converging Science and Technology, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
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48
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Bejtka K, Milano G, Ricciardi C, Pirri CF, Porro S. TEM Nanostructural Investigation of Ag-Conductive Filaments in Polycrystalline ZnO-Based Resistive Switching Devices. ACS APPLIED MATERIALS & INTERFACES 2020; 12:29451-29460. [PMID: 32508083 PMCID: PMC8008384 DOI: 10.1021/acsami.0c05038] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 06/08/2020] [Indexed: 06/01/2023]
Abstract
Memristive devices based on a resistive switching mechanism are considered very promising for nonvolatile memory and unconventional computing applications, even though many details of the switching mechanisms are not yet fully understood. Here, we report a nanostructural study by means of high-resolution transmission electron microscopy and spectroscopy techniques of a Ag/ZnO/Pt memristive device. To ease the localization of the filament position for its characterization, we propose to use the guiding effect of regular perturbation arrays obtained by FIB technology to assist the filament formation. HRTEM and EDX were used to identify the composition and crystalline structure of the so-obtained conductive filaments and surrounding regions. It was determined that the conducting paths are composed mainly of monocrystalline Ag, which remains polycrystalline in some circumstances, including the zone where the switching occurs and at secondary filaments created at the grain boundaries of the polycrystalline ZnO matrix. We also observed that the ZnO matrix shows a degraded quality in the switching zone, while it remains unaltered in the rest of the memristive device.
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Affiliation(s)
- Katarzyna Bejtka
- Center
for Sustainable Future Technologies @ POLITO, Istituto Italiano di Tecnologia, Via Livorno 60, Turin 10144, Italy
| | - Gianluca Milano
- Center
for Sustainable Future Technologies @ POLITO, Istituto Italiano di Tecnologia, Via Livorno 60, Turin 10144, Italy
- Department
of Applied Science and Technology, Politecnico
di Torino, C.so Duca degli Abruzzi 24, Turin 10129, Italy
| | - Carlo Ricciardi
- Department
of Applied Science and Technology, Politecnico
di Torino, C.so Duca degli Abruzzi 24, Turin 10129, Italy
| | - Candido F. Pirri
- Center
for Sustainable Future Technologies @ POLITO, Istituto Italiano di Tecnologia, Via Livorno 60, Turin 10144, Italy
- Department
of Applied Science and Technology, Politecnico
di Torino, C.so Duca degli Abruzzi 24, Turin 10129, Italy
| | - Samuele Porro
- Department
of Applied Science and Technology, Politecnico
di Torino, C.so Duca degli Abruzzi 24, Turin 10129, Italy
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Ma Y, Cullen DA, Goodwill JM, Xu Q, More KL, Skowronski M. Exchange of Ions across the TiN/TaO x Interface during Electroformation of TaO x-Based Resistive Switching Devices. ACS APPLIED MATERIALS & INTERFACES 2020; 12:27378-27385. [PMID: 32441092 DOI: 10.1021/acsami.0c06960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The valence change model describes the resistive switching in metal oxide-based devices as due to electroreduction of the oxide and subsequent electromigration of oxygen vacancies. Here, we present cross-sectional X-ray energy-dispersive spectroscopy elemental maps of Ta, O, N, and Ti in electroformed TiN/TaO2.0/TiN structures. O, N, and Ti were exchanged between the anode and the functional oxide in devices formed at high power (∼1 mW), but the exchange was below the detection limit at low power (<0.5 mW). All structures exhibit a similar Ta-enriched and O-depleted filament formed by the elemental segregation in the functional oxide by the temperature gradient. The elemental interchange is interpreted as due to Fick's diffusion caused by high temperatures in the gap of the filament and is not an essential part of electroformation.
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Affiliation(s)
- Yuanzhi Ma
- Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - David A Cullen
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jonathan M Goodwill
- Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Qiyun Xu
- Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Karren L More
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Marek Skowronski
- Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213, United States
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50
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Multi-Bit Biomemory Based on Chitosan: Graphene Oxide Nanocomposite with Wrinkled Surface. MICROMACHINES 2020; 11:mi11060580. [PMID: 32531883 PMCID: PMC7344448 DOI: 10.3390/mi11060580] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/04/2020] [Accepted: 06/05/2020] [Indexed: 01/17/2023]
Abstract
Chitosan (CS) is one of the commonly affluent polysaccharides that are attractive biomaterials as they are easily found in different organisms and are biocompatible. An environment-friendly multi-bit biomemory was successfully achieved on the basis of CS as a favorable candidate for resistive-switching memory applications. By incorporating graphene oxide (GO) into CS, the multi-bit biomemory device (indium tin oxide (ITO)/CS:GO/Ni) was obtained through the solution-processable method, which had a high current ratio among a high, intermediate, and low resistance state as well as a low SET/RESET voltage. GO acting as trapping sites in the active layer might be responsible for the biomemory mechanism. This research opens up a new avenue towards renewable and environmentally benign CS-based materials for biodegradable electronic devices.
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