Article
Engineering, Electrical & Electronic
Yu-Chung Lien, Tsung-Ta Wu, S. Simon Wong
Summary: Demonstrated is a resistive random-access memory (RRAM) utilizing nitrogen-doped aluminum oxide (AlOxNy) resistive dielectric deposited with atomic layer deposition (ALD), suitable for high-density 3-D vertical via array. The RRAM exhibits almost forming-free operation, sub-microamperes programming currents, and appropriate resistance ranges with ALD electrodes. As the via size scales down, the set voltage and reset current decrease, while the memory window widens due to the device's 3-D nature, showing programming endurance of 5 x 10(4) cycles and retention up to 10 years at 90°C.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Chemistry, Physical
Seung Woo Han, Moo Whan Shin
Summary: This study fabricates a high-performance flexible RRAM device using a precisely controlled UV laser annealing process, which changes the concentration of O Frenkel defect pairs in the ZnO layer and produces a ZnO/Al mixed interface layer with high quality oxygen reservoirs. The laser-annealed flexible RRAM shows stable resistive switching, performance enhancement, high on/off ratio, cycling endurance, and low power consumption, even at a bending radius of up to 5 mm.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Seung Woo Han, Chul Jin Park, Moo Whan Shin
Summary: This study demonstrates that the diffusion of aluminum atoms and oxygen vacancies significantly affect the resistive switching behavior of zinc oxide-based random resistive access memory (RRAM). The diffusion of aluminum atoms into the zinc oxide layer acts as dopants, producing additional oxygen vacancies and contributing to the formation of conductive filaments. Additionally, the formation of an aluminum oxide layer by the redox reaction between aluminum atoms and oxygen leads to the instability of the reset process.
SURFACES AND INTERFACES
(2022)
Article
Engineering, Electrical & Electronic
Ruofei Hu, Jianshi Tang, Yue Xi, Zhixing Jiang, Yuyao Lu, Bin Gao, He Qian, Huaqiang Wu
Summary: A nitrogen-oxyanion-doped hafnium oxide RRAM with improved forming voltage, on/off ratio, and endurance is demonstrated. The critical electric field of N-doped RRAM for forming is 40% lower than that of undoped RRAM. The N-doped RRAM achieves 3x improvement in on/off ratio and 10x improvement in endurance at the forming voltage of 2 V, which is suitable for integration with advanced silicon technology nodes.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Yu-Bo Wang, Ting-Chang Chang, Shih-Kai Lin, Pei-Yu Wu, Yong-Ci Zhang, Yung-Fang Tan, Wen-Chung Chen, Chung-Wei Wu, Sheng-Yao Chou, Kuan-Ju Zhou, Li-Chuan Sun, Xin-Ying Tsai, Simon M. Sze
Summary: This work proposes a forming-free HfO2-based RRAM using X-ray irradiation, which overcomes the need for a larger forming voltage in the conventional forming process with scaling. Additionally, large irradiation area benefits mass production of memory devices. The forming-free device shows better memory window and comparable reliability compared to the device without X-ray irradiation. Through current-fitting technique and irradiation experiments, a physical model is proposed to explain the mechanism of forming-free RRAM from X-ray irradiation.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Chemistry, Physical
Harry Chung, Hyungsoon Shin, Jisun Park, Wookyung Sun
Summary: A unified model is proposed in this paper to describe the electrical characteristics of RRAM devices, which exhibit two different resistive switching phenomena. By combining the Voltage ThrEshold Adaptive Memristor (VTEAM) model and the tungsten-based model, the performance of the model is enhanced by reflecting the physical properties of the switching operation. The accuracy of the I-V relationship curve tails of the device is significantly improved by adjusting the ranges of unified internal state variables. Furthermore, the unified model describes a variety of electrical characteristics and yields continuous results by using the device's current-voltage relationship without dividing its fitting conditions.
Article
Physics, Applied
Xuping Shen, Haixia Gao, Yiwei Duan, Yuxin Sun, Jingshu Guo, Zhenxi Yu, Shuliang Wu, Xiaohua Ma, Yintang Yang
Summary: This study investigates the effect of crystallinity on the performance of AlN-based resistive random access memory, demonstrating that increasing the crystallinity of an AlN film can lead to higher switching voltages and wider memory windows in devices. Additionally, reliability of the devices is improved. The findings suggest that crystallization reduces vacancies within the AlN film and enhances the local effects of grain boundaries on electron transport, ultimately contributing to improved device performance. This research serves as a valuable platform for further enhancements in AlN-based devices.
APPLIED PHYSICS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Dongsheng Cui, Yawei Du, Zhenhua Lin, Mengyang Kang, Yifei Wang, Jie Su, Jincheng Zhang, Yue Hao, Jingjing Chang
Summary: A memory device with an Ag/Ga2O3/Pt structure has been successfully fabricated, exhibiting both bipolar resistive switching (BRS) and unipolar resistive switching (URS) behaviors. It was found that the bipolar and unipolar modes can be set by applying a positive voltage with the same compliance current (I-cc) of 1 mA. The reset process involves a polarity change of sweeping voltages without I-cc to switch between the bipolar and unipolar modes. The conduction mechanisms are identified as conducting filaments (CFs) for the low resistance state (LRS), and schottky emission for BRS, and space charge limited conduction mechanism for URS in the high resistance states (HRS), respectively.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Siyao Yang, Qi Hu, Bin Gao, Jianshi Tang, Feng Xu, Yuyao Lu, Peng Yao, Yue Xi, He Qian, Huaqiang Wu
Summary: This study presents a high-quality adaptive relaxation signal analysis method to address the relaxation effect in analog resistive random access memory (RRAM) that leads to accuracy loss in computation. The study comprehensively analyzes different fluctuations and mechanisms in the relaxation effect and proposes an optimization strategy of increasing pulsewidth to mitigate the relaxation effect.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Materials Science, Multidisciplinary
Hassan Algadi, Chandreswar Mahata, Turki Alsuwian, Muhammad Ismail, Daewoong Kwon, Sungjun Kim
Summary: A RRAM device was fabricated using Pt-NPs deposited by atomic layer deposition, showing controlled filament formation and multilevel conductance, achieving excellent resistive switching properties. Potentiation/depression characteristics were successfully demonstrated by applying increasing voltage pulses, indicating the device's learning potential.
Article
Chemistry, Multidisciplinary
Taehun Lee, Hae-In Kim, Yoonjin Cho, Sangwoo Lee, Won-Yong Lee, Jin-Hyuk Bae, In-Man Kang, Kwangeun Kim, Sin-Hyung Lee, Jaewon Jang
Summary: Yttrium oxide (Y2O3) resistive random-access memory (RRAM) devices were fabricated using the sol-gel process. The devices showed conventional bipolar RRAM characteristics without the need for a high-voltage forming process. The study investigated the effect of current compliance on the devices and found that resistance values decreased as set current compliance values increased. By controlling these values, the formation of pure Ag conductive filaments could be restricted. The Y2O3 RRAM devices demonstrated potential for use in neural networks and achieved effective digit image classification.
Article
Chemistry, Physical
A. Napolean, N. M. Sivamangai, R. NaveenKumar, N. Nithya
Summary: The study found that devices formed with annealing and high ambient temperature had lower operating voltage, improved uniformity, and reliability compared to devices formed without annealing at low temperature.
Article
Biochemistry & Molecular Biology
Jin Mo Kim, Sung Won Hwang
Summary: Flexible memristive devices using reduced graphene oxide (RGO) nanosheet nanocomposites with an embedded GQD layer were investigated for developing resistive random access memory (RRAM) devices. The resistive switching behavior of composites and hybrid bilayers based on graphene quantum dots and HfOx was explored to improve electrical properties. Increasing the concentration of PVP-GQD led to changes in V-f and decreased the depth of interfacial defects, facilitating the electrophoresis of Al+ ions to the PVP GQD layer and HfOx thin film.
Article
Nanoscience & Nanotechnology
Il-Kwon Oh, Asir Intisar Khan, Shengjun Qin, Yujin Lee, H. -S. Philip Wong, Eric Pop, Stacey F. Bent
Summary: This study explores the application of area-selective atomic layer deposition (AS-ALD) technique in the fabrication of RRAM devices and finds that AS-ALD can improve the reliability and accuracy of RRAM, regardless of device size. The application of this technique will contribute to the improvement of other data storage technologies.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Paola Trotti, Sami Oukassi, Gabriel Molas, Mathieu Bernard, Francois Aussenac, Gael Pillonnet
Summary: This study delves into the innovative idea of a hybrid dual-behavior device based on emerging nonvolatile memory technology, aiming to achieve data retention and energy storage. Evaluation of electrochemical characteristics on RRAM shows potential energy storage capability and proposes design concepts for various emerging and standard applications.
ADVANCED ELECTRONIC MATERIALS
(2021)
Article
Physics, Applied
Chang Liu, Jia-Bin Fang, Yan-Qiang Cao, Di Wu, Ai-Dong Li
APPLIED PHYSICS LETTERS
(2020)
Article
Engineering, Electrical & Electronic
Lin Zhu, Xiao-Jie Liu, Yan-Qiang Cao, Ai-Dong Li, Di Wu
Summary: Gadolinium (Gd) and Silicon (Si) co-doped HfO2 gate dielectric thin films were successfully prepared by atomic layer deposition (ALD) with precise control over the doping concentration. The band gap of the films was found to have a positive correlation with the doping concentration, while the valence band offset initially decreased and then increased with doping concentration. The electrical properties of the films were significantly improved compared to pure HfO2 films, with a decreased leakage current density by at least one order of magnitude.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Nanoscience & Nanotechnology
Jia-Bin Fang, Shao-zhong Chang, Qiang Ren, Tao-qing Zi, Di Wu, Ai-Dong Li
Summary: This study explores the use of titanicone coating prepared by molecular layer deposition as a solid electrolyte interphase layer for silicon anodes, aiming to enhance the performance of lithium-ion batteries. The optimized titanicone-coated anode shows high cycling stability and excellent rate performance, indicating the potential for next-generation lithium-ion batteries.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Jia-Bin Fang, Yan-Qiang Cao, Shao-Zhong Chang, Fu-Rui Teng, Di Wu, Ai-Dong Li
Summary: By utilizing a dual-film design consisting of flexible porous zincone and rigid compact TiO2, researchers were able to enhance the lithiation/delithiation process of silicon materials, achieving high electrochemical performance and cycling stability. The structure of the dual-film can alleviate internal stress of the silicon materials, provide sufficient mechanical strength and protection to the silicon particles, resulting in improved stability and capacity during cycling. The study demonstrated that the Si@zincone/TiO2 electrode exhibits excellent electrochemical performance and a low capacity-fading rate.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Jin Lei, Wen-Juan Ding, Chang Liu, Di Wu, Wei-Min Li, Ai-Dong Li
Summary: In this work, a Pt/Hf-based hybrid memory with excellent resistive switching characteristics and multi-state data storage capability was fabricated. The resistive switching mechanism based on conducting filaments was proposed, favoring occurrence at the interface of the hybrid Hf-HQ layer and Al2O3 layer for brilliant performances. Flexible hybrid memory devices on bendable mica showed great potential in flexible multilevel resistive random access memory applications.
Article
Chemistry, Physical
Shaozhong Chang, Jiabin Fang, Kai Liu, Zihan Shen, Lin Zhu, Xin Jin, Xuejin Zhang, Chaoquan Hu, Huigang Zhang, Ai-dong Li
Summary: By using molecular layer deposition (MLD) technology, the research team conformedly fabricated zincone (ZnHQ) on 3D copper nanowires (CuNWs), forming a stable solid electrolyte interphase (SEI), which improves the Coulombic efficiency and inhibits dendritic growth of lithium metal anodes, resulting in excellent cyclability.
ADVANCED ENERGY MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Fu-Rui Teng, Tao-Qing Zi, Jia-Bin Fang, Chang Liu, Di Wu, Ai-Dong Li
Summary: This paper presents an ultrasensitive wearable strain sensor based on the parallel connection architecture of Ir-nanoparticles-modified carbon nanotubes (Ir NPs@CNTs) and two Pt layers on a reticular patterned polymer substrate (Dragon Skin 30, DS). The sensor exhibits high sensitivity, wide strain range, low limit of detection, fast response time, and long-term durability. It also shows heat sensitivity at various environmental temperatures. The wearable sensor has been successfully utilized for human-motion detection with improved comprehensive performance, indicating its promising applications in flexible electronics and artificial intelligent fields.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Qiang Ren, Xin-Yue Zhang, Ji-An Chen, Jia-Bin Fang, Tao-Qing Zi, Lin Zhu, Chang Liu, Min Han, Yan-Qiang Cao, Ai-Dong Li
Summary: A high performance flexible hydrogen sensor was developed using ultrathin SnO2 film decorated by Pd nanoparticles (NPs) on polyimide (PI) based on versatile atomic layer deposition (ALD) and cluster beam deposition (CBD). The influence of Pd NPs loading amount and operating temperature on the sensors' performance was studied. The sensors showed extremely high response over 20000 to 30 ppm H-2 at the relatively low operating temperature of 75-125 degrees C, with a wide detection range of 0.1-5000 ppm and a low limit of detection (LOD) of 100 ppb at 125 degrees C.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Jiabin Fang, Jianguo Li, Lijun Qin, Aidong Li, Hao Feng
Summary: In this study, a lithium-containing laminated Li2O-lithicone hybrid film was fabricated on a silicon electrode using ALD and MLD techniques. The laminated structure design relieved the interfacial stress and improved the integrity and reactivity of the silicon composite anode. The lithium-based laminated film also enhanced the Coulombic efficiency and cycling stability of the silicon anode, showing great potential for advanced lithium-ion batteries.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Tangjie Cheng, Zebin Zhu, Xinxin Wang, Lin Zhu, Aidong Li, Liyong Jiang, Yanqiang Cao
Summary: Metal nanogaps can confine electromagnetic field into extremely small volumes, exhibiting strong surface plasmon resonance effect. However, it is challenging to fabricate large-scale nanogaps with precise control of gap size, limiting the practical applications of metal nanogaps.
Editorial Material
Nanoscience & Nanotechnology
Sheng Hsiung Chang, Xiangbo Meng, Jian Liu, Dung-Sheng Tsai, Xinwei Wang, Chiashain Chuang, Cheng-Ying Chen, Aidong Li
Summary: This Focus highlights the significance of manipulating atomic and molecular layers for various applications. It features 15 original research papers that showcase the applications of techniques such as atomic layer deposition, chemical vapor deposition, and wet chemistry in manipulating atomic and molecular layers in areas such as lithium-ion batteries, supercapacitors, catalysis, field-effect transistors, and optoelectronics.
Article
Chemistry, Physical
Xu Zhang, Zhongchao Zhou, Rui Xu, Jiayi Guo, Lina Xu, Yihong Ding, Hongping Xiao, Xinhua Li, Aidong Li, Guoyong Fang
Summary: In this work, the reaction mechanism for nickel sulfide atomic layer deposition (ALD) was investigated using density functional theory (DFT) calculations. The results showed that the nickel amidine ligands can easily undergo elimination reactions on the sulfhydrylated surface, while the resulting N,N'-di-tert-butylacetamidine molecule strongly interacts with the Ni atom and is difficult to desorb. During the subsequent H2S reaction, the N,N'-di-tert-butylacetamidine molecule can be exchanged with the H2S precursor, leading to the formation of sulfhydrylated groups and further sulfide deposition.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Inorganic & Nuclear
Lin Zhu, Geng-Lai Yang, Wen-Juan Ding, Yan-Qiang Cao, Wei-Ming Li, Ai-Dong Li
Summary: This study deeply explores the growth behavior of iridium (Ir) metal formed by atomic layer deposition (ALD) in high aspect ratio nanostructures. It is found that surface hydrophilicity is crucial for the nucleation of ALD Ir. The infiltration depth of ALD Ir in the nanostructures is found to be proportional to the pore diameter and the square root of the Ir precursor pulse time. Additionally, the appropriate O-2 partial pressure should be chosen for ALD Ir in high aspect ratio materials. This research is valuable for surface modification or coating of metal in high aspect ratio nanostructures.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Physical
Yiqing Wei, Huichao He, Chang Liu, Liuqing Yang, Xiaoyong Wang, Aidong Li, Yujie Xiong, Qing Shen, Yong Zhou, Zhigang Zou
Summary: A new type of α-Fe2O3/Ag/CdS ternary heterojunction film was constructed and investigated for solar water oxidation, achieving higher photocurrent density by enhancing charge separation and transfer efficiency as well as reducing electron-hole recombination through surface plasmon resonance effect.
CATALYSIS SCIENCE & TECHNOLOGY
(2021)
Article
Chemistry, Inorganic & Nuclear
Jia-Bin Fang, Qiang Ren, Chang Liu, Ji-An Chen, Di Wu, Ai-Dong Li
Summary: This work utilized a conductive Al2O3/carbon layer derived from molecular layer deposition to stabilize the structure of cactus-like NiCo2O4 nanocrystal anodes, improving the reversible capacity and long-term stability of lithium-ion batteries.
DALTON TRANSACTIONS
(2021)
