Article
Materials Science, Multidisciplinary
Anirudh Kumar, KM. Preeti, Satendra Pal Singh, Sejoon Lee, Ajeet Kaushik, Sanjeev K. Sharma
Summary: Neuromorphic computing systems emulate biological synapses electronically for information handling and processing. Memristors are emerging as crucial components for AI and IoT circuits to develop energy-efficient intelligent systems. This review focuses on n-ZnO:Poly hybrid nanocomposite-based memristors and their resistive switching mechanisms, progress, and challenges. The synaptic functions of these memristors as artificial synapses for neural networks are explored, and the key requirements for AI and IoT electronics are highlighted.
Article
Chemistry, Physical
Miaocheng Zhang, Xingyu Chen, Ziyang Chen, Ronghui Dan, Yixin Wei, Huanhuan Rong, Qiang Wang, Xi Chen, Aoze Han, Yu Wang, Weijin Shao, Hao Zhang, Yerong Zhang, Lei Wang, Jianguang Xu, Yi Tong
Summary: Novel barium ferrite-based ferroelectric memristors with MXene Ti3C2 enhancement have been fabricated. These memristors can convert from stable threshold-switching to resistive-switching behavior under compliance currents. A one-bit adder circuit was demonstrated and a deep neural network was designed for image classification using these ferroelectric crossbar arrays.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Wanxuan Xie, Yang Zhong, Dehui Wang, Lun Zhong, Lu Han, Qiongfen Yang, Wenjing Jie
Summary: This study demonstrates the co-existence of digital and analog resistive switching in synaptic memristors based on 2D BiOI nanosheets. The memristors show typical bipolar resistive switching behaviors and can emulate learning-forgetting experience and Pavlov's dog experiment.
MATERIALS & DESIGN
(2023)
Article
Materials Science, Multidisciplinary
Ghulam Dastgeer, Haider Abbas, Duk Young Kim, Jonghwa Eom, Changhwan Choi
Summary: A nano-sized two-terminal memristor demonstrating volatile threshold switching has been fabricated to emulate biological synaptic functions in neuromorphic computing. The device exhibits a large I-ON/OFF ratio and the experimental realization of synaptic behavior validates a psychological model of human brain learning. Input pulses with different spike-times are used to replicate synaptic functionalities.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2021)
Article
Chemistry, Physical
Yanmei Sun, Nian He, Dianzhong Wen, Fengyun Sun
Summary: Researchers reported a memristor based on Co-Ni LDH hybrid nanosheets, showing multiple progressive resistance switches when applying pulses, which can simulate synaptic functions in biology. By studying the microstructure, the O vacancy was identified as the physical mechanism of the resistance switch behavior. This work reveals the excellent application potential of Co-Ni LDH nanosheets in memristors.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Lukas Voelkel, Dennis Braun, Melkamu Belete, Satender Kataria, Thorsten Wahlbrink, Ke Ran, Kevin Kistermann, Joachim Mayer, Stephan Menzel, Alwin Daus, Max C. Lemme
Summary: The switching mechanism of multilayer hexagonal boron nitride (h-BN) threshold memristors with nickel (Ni) electrodes is investigated through temperature-dependent current-voltage measurements. The formation and retraction of nickel filaments along boron defects in the h-BN film are proposed as the resistive switching mechanism. The electrical data are corroborated with TEM analyses, confirming the viability of using temperature-dependent current-voltage measurements as a valuable tool for analyzing resistive switching phenomena in memristors made of 2D materials. The memristors exhibit wide current operation range, low standby currents, low cycle-to-cycle variability, and a large On/Off ratio.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Review
Chemistry, Multidisciplinary
Mario Lanza, Fei Hui, Chao Wen, Andrea C. Ferrari
Summary: Resistive switching (RS) devices are metal/insulator/metal cells that can change their electrical resistance when electrical stimuli are applied between the electrodes, and they can be used to store and compute data. Planar crossbar arrays of RS devices can offer a high integration density (>10(8) devices mm(-)(2)) and this can be further enhanced by stacking them three-dimensionally. The advantage of using layered materials (LMs) in RS devices compared to traditional phase-change materials and metal oxides is that their electrical properties can be adjusted with a higher precision.
ADVANCED MATERIALS
(2023)
Article
Physics, Applied
Xuepeng Xiang, Jingjing Rao, Zuyun He, Mengzhen Zhou, Qicheng Huang, Yuan Gao, Zhen Fan, Xinwei Wang, Yan Chen
Summary: The uniaxial strain of SrCoO2.5 (SCO) thin film can be controlled by low-energy helium irradiation, leading to improved resistive switching performance. The device irradiated with 1 x 10(14) ions/cm(2) shows the best performance.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Mathematics, Interdisciplinary Applications
Yuriy Gerasimov, Evgenii Zykov, Nikita Prudnikov, Max Talanov, Alexander Toschev, Victor Erokhin
Summary: This paper is dedicated to the experimental study of learning properties of systems, based on polyaniline (PANI) memristive devices. The study demonstrates the impact of signals with different forms, amplitudes, and frequencies on memristive device conductance, with pulse width modulation appearing as the most adequate method for implementing neuromorphic circuits.
CHAOS SOLITONS & FRACTALS
(2021)
Article
Chemistry, Multidisciplinary
Ruijing Ge, Xiaohan Wu, Liangbo Liang, Saban M. Hus, Yuqian Gu, Emmanuel Okogbue, Harry Chou, Jianping Shi, Yanfeng Zhang, Sanjay K. Banerjee, Yeonwoong Jung, Jack C. Lee, Deji Akinwande
Summary: This study investigates the phenomenon of NVRS effect in 2D non-conductive materials, including TMDs, TMD heterostructures, and atomically thin insulators. The results show low switching voltage, large ON/OFF ratio, and forming-free characteristics in these materials, providing insights for the understanding and applications of defects in 2D materials.
ADVANCED MATERIALS
(2021)
Article
Multidisciplinary Sciences
Markus Hellenbrand, Babak Bakhit, Hongyi Dou, Ming Xiao, Megan O. Hill, Zhuotong Sun, Adnan Mehonic, Aiping Chen, Quanxi Jia, Haiyan Wang, Judith L. MacManus-Driscoll
Summary: A design concept of phase-separated amorphous nanocomposite thin films is presented that enables interfacial resistive switching in hafnium oxide-based devices. By incorporating an average of 7% Ba into hafnium oxide, films consisting of amorphous HfOx host matrix interspersed with Ba-rich nanocolumns are formed. The resistive switching is restricted to an interfacial Schottky-like energy barrier, which can be tuned by ionic migration under an applied electric field. The resulting devices exhibit stable reproducibility and switching endurance, allowing for multiple intermediate resistance states and synaptic spike-timing-dependent plasticity.
Article
Nanoscience & Nanotechnology
Omesh Kapur, Dongkai Guo, Jamie Reynolds, Yisong Han, Richard Beanland, Liudi Jiang, C. H. (Kees) de Groot, Ruomeng Huang
Summary: A memristor based on silicon carbide (SiC) has been developed, showing excellent binary resistive switching and the ability to emulate various synaptic functions. The conductance of this memristor can be modulated through the application of different signals, successfully replicating the synaptic function of learning-forgetting-relearning processes.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Materials Science, Ceramics
Muhammad Ismail, Haider Abbas, Andrey Sokolov, Chandreswar Mahata, Changhwan Choi, Sungjun Kim
Summary: By introducing an amorphous Ta2O5 layer into the ZrO2 memristor, significant improvements in resistive switching and synaptic characteristics were achieved, leading to multilevel storage capability and effective mimicry of biological synaptic learning patterns.
CERAMICS INTERNATIONAL
(2021)
Article
Nanoscience & Nanotechnology
Young Geun Song, Ji Eun Kim, Jae Uk Kwon, Suk Yeop Chun, Keunho Soh, Sahn Nahm, Chong-Yun Kang, Jung Ho Yoon
Summary: A highly reliable threshold switching device, based on Ag and SiO2 nanorods, that is immune to atmospheric changes has been developed. This device exhibits switching characteristics that are electroforming-free, repeatable, consistent, and resistant to changes in ambient conditions and compliance levels during operation.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Konstantinos Rogdakis, Konstantinos Chatzimanolis, George Psaltakis, Nikolaos Tzoganakis, Dimitris Tsikritzis, Thomas D. Anthopoulos, Emmanuel Kymakis
Summary: In this study, a three-terminal mixed-halide perovskite memristive device with gate-tunable synaptic functions operating at low potentials is demonstrated. The device shows extended endurance and state retention, and the channel conductance can be modulated by applying a VG potential, reducing the operating electric field required.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Physical
Mumtaz Ali, Rabia Riaz, Aima Sameen Anjum, Kyung Chul Sun, Hui Li, Sung Hoon Jeong, Min Jae Ko
Summary: This study explored the potential of nitrogen-doped graphene quantum dots to induce 3D porous orientation of graphene oxide nanosheets, enhancing electrolyte transport rates and electrocatalytic activity. The resulting 3D hierarchically porous carbon architecture showed enhanced performance in dye-sensitized solar cells, comparable to Pt electrodes, and can be utilized in emerging electrocatalytic applications such as supercapacitors, water splitting, and battery electrodes.
Article
Energy & Fuels
Seong Yeon Ko, Benjamin Nketia-Yawson, Hyungju Ahn, Jea Woong Jo, Min Jae Ko
Summary: By modulating the chemical structure, optimized the crystal characteristics and charge transport behavior of polythiophenes. Enhanced in-plane and out-of-plane charge transport efficiency was achieved simultaneously. The optimized random polymer showed significantly improved electron mobility in both field-effect transistor and space-charge-limited current device, as well as higher efficiency in perovskite solar cells compared to homopolymer analogue.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Chemistry, Multidisciplinary
Pitchiah Esakki Karthik, Hashikaa Rajan, Vasanth Rajendiran Jothi, Min Jae Ko, Sung Chul Yi
Summary: This study investigates the enhanced oxygen evolution reaction behavior of a CoSe electrode under hydrogen-induced embrittlement. Results from linear sweep voltammetry, impedance analysis, and Tafel analysis support the higher activity of the hydrogen-embrittled CoSe electrode. High-resolution transmission electron microscopy confirms the diffusion of hydrogen into the metal lattice.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Engineering, Environmental
Jigeon Kim, Sanghun Han, Gyudong Lee, Jongmin Choi, Min Jae Ko, Younghoon Kim
Summary: This paper demonstrates a single-step fabrication approach for conductive thick CsPbI3-PQD absorbers based on surface ligand manipulation, which shows improved power conversion efficiency in PQD solar cells. By employing a different post-treatment method and utilizing solution-phase ligand exchange PQDs, the efficiency of solar cells was significantly increased.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Materials Science, Multidisciplinary
Min-Woo Lee, Jae-Yup Kim, Min Jae Ko
Summary: This study presents a simple and effective method of molecular modification to improve the photovoltaic and photo-electrochemical properties of D-IT-A organic sensitizers. The incorporation of fluorine as an additional acceptor unit enhances the electron transfer and decreases the energy gap. Furthermore, fluorine also induces J-aggregation and increases the dye loading on the photoanode, resulting in improved photocurrent and photovoltage of DSSCs.
ORGANIC ELECTRONICS
(2022)
Article
Nanoscience & Nanotechnology
Sunkyu Kim, Yeongje Lee, Jongmin Park, Yujin So, Hee-Tae Jung, Min Jae Ko, Jong Chan Won, Sunho Jeong, Yun Ho Kim
Summary: In this study, an eco-friendly synthesis method was proposed for creating hybrid composites with ultralow dielectric properties for true 5G communication. The composites were made from aqueous aromatic polyimide polymers and dual-porous silica nanoparticles. The synthesis process involved the one-step polymerization of water-soluble poly(amic acid) in an aqueous solution, along with the functionalization of macroporous silica nanoparticles to ensure excellent dispersion stability. By varying the amount of dual-porous silica nanoparticles in the polyimide matrix, it was found that the addition of 5 wt% nanoparticles resulted in a composite with ideal dielectric properties and satisfactory mechanical characteristics.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Jiwon Lee, Sungmi Yoo, Dongkyu Kim, Yun Ho Kim, Sungmin Park, No Kyun Park, Yujin So, Jinsoo Kim, Jongmin Park, Min Jae Ko, Jong Chan Won
Summary: This study presents a low-dielectric copolyimide material by combining molecular design and composition control. The composition was adjusted to regulate the movement of polymer chains and the density of dipole moments, resulting in a material with low dielectric constant and loss at 28 GHz. This research provides a design factor for advanced copolymers in telecommunication applications with fast signal transport speed and minimum signal loss.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Nanoscience & Nanotechnology
Jian Cheng, In Choi, Wooyeon Kim, Hui Li, Bonkee Koo, Min Jae Ko
Summary: Perovskite-based tandem solar cells with a 2.0 eV band gap were successfully deposited using acetic acid and isopropanol as solvents. The formation of acetate anions in situ effectively stabilized the intrinsic defects in the perovskite films, improving their phase stability. This strategy led to a high open-circuit voltage (1.325V) and a power conversion efficiency of 10.62%, which is close to the state-of-the-art for perovskite solar cells with a 2.0 eV band gap.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Xinpeng Zhang, Xiangyu Li, Lei Tao, Zemin Zhang, Hao Ling, Xue Fu, Shibo Wang, Min Jae Ko, Jingshan Luo, Jiangzhao Chen, Yuelong Li
Summary: An anti-solvent optimized adduct strategy is proposed to control perovskite crystallization in wide-bandgap perovskite solar cells. This strategy effectively reduces defect density and improves the open-circuit voltage and power conversion efficiency.
Article
Chemistry, Physical
Boncheol Ku, Bonkee Koo, Wooyeon Kim, Younghoon Kim, Yu-Rim Jeon, Min Jae Ko, Changhwan Choi
Summary: CsPbX3 (X = I, Br, or Cl) perovskite materials with versatile and excellent photoelectric properties have attracted great interest in various devices. However, their application is hindered by the unstable crystalline phase at room temperature. To address this issue, a stable CsPbI3 perovskite quantum dots (CsPbI3-PQDs) thin film was fabricated using in-situ ligand exchange layer-by-layer self-assembly (LbL SA). These thin films showed not only nano-scale thickness control but also tunable electrical properties. A photonic synapse was fabricated on fluorine-doped tin oxide (FTO) substrate using CsPbI3-PQD, exhibiting photo-sensitive current-voltage characteristics and emulating essential synaptic behaviors induced by photonic stimulus. Additionally, a CsPbI3-PQD/a-IGZO heterojunction synaptic device was fabricated, demonstrating improved synaptic behaviors under various visible stimuli.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Kicheon Yoo, Ashok Kumar Kaliamurthy, Jae-Joon Lee, Min Jae Ko
Summary: The performance of quasi-solid-state dye-sensitized solar cells (qs-DSSCs) using Polyvinylpyrrolidone/Polyethylene glycol (PVP/PEG) blends was investigated over a wide temperature range. The PVP/PEG blend exhibited low glass-transition temperature and high ionic conductivity, leading to high power conversion efficiency (PCE) at both low and ambient temperatures. Additionally, the qs-DSSC with PVP/PEG showed excellent long-term stability.
JOURNAL OF POWER SOURCES
(2023)
Article
Chemistry, Physical
Hashikaa Rajan, Sengeni Anantharaj, Jin-Kuk Kim, Min Jae Ko, Sung Chul Yi
Summary: The major issue with alkaline hydrogen evolution reaction (HER) is the poor kinetics resulting from water dissociation and discharge of protons. In this study, we developed a trimetallic catalyst (CoMoRu/CC) to overcome these issues. The Co component promoted water dissociation, while the Ru component efficiently discharged protons, resulting in H2 evolution. The Mo component assisted in the optimal bonding of H-ad to the catalytic sites and prevented Ru from getting poisoned.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Review
Polymer Science
Kiwon Choi, Ahyeon Noh, Jinsil Kim, Pyong Hwa Hong, Min Jae Ko, Sung Woo Hong
Summary: Self-healing polymeric materials, which can autonomously restore damages, are at the forefront of sustainable materials research and play a crucial role in mitigating plastic waste. Historical research focused on extrinsic self-healing systems, while recent advancements have shifted towards intrinsic self-healing systems.
Article
Chemistry, Physical
Sanghun Han, Jigeon Kim, Dong Eon Kim, Min Jae Ko, Jongmin Choi, Se-Woong Baek, Younghoon Kim
Summary: The surface ligand exchange process of all-inorganic CsPbI3 perovskite colloidal quantum dots enables the fabrication of conductive PQD solids for photovoltaic absorbers. However, these absorbers do not effectively absorb solar light. This study demonstrates that introducing nanophotonic structures in CsPbI3-PQD solar cells increases light absorption, thereby improving the PV performance.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
