The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Wei D. Lu - One of the best experts on this subject based on the ideXlab platform.
-
Tuning Ionic Transport in Memristive Devices by Graphene with Engineered Nanopores
ACS Nano, 2016Co-Authors: Jihang Lee, Kai Sun, Emmanouil Kioupakis, Chao Du, Wei D. LuAbstract:Memristors, based on inherent memory effects in simple two-terminal structures, have attracted tremendous interest recently for applications ranging from Nonvolatile Data storage to neuromorphic computing based on non-von Neumann architectures. In a memristor, the ability to modulate and retain the state of an internal variable leads to experimentally observed resistive switching (RS) effects. Such phenomena originate from internal, microscopic ionic migration and associated electrochemical processes that modify the materials' electrical and other physical properties. To optimize the device performance for practical applications with large-size arrays, controlling the internal ionic transport and redox reaction processes thus becomes a necessity, ideally at the atomic scale. Here we show that the RS characteristics in tantalum-oxide-based memristors can be systematically tuned by inserting a graphene film with engineered nanopores. Graphene, with its atomic thickness and excellent impermeability and chemical stability, can be effectively integrated into the device stack and can offer unprecedented capabilities for the control of ionic dynamics at the nanoscale. In this device structure, the graphene film effectively blocks ionic transport and redox reactions; thereby the oxygen vacancies required during the RS process are allowed to transport only through the engineered nanosized openings in the graphene layer, leading to effective modulation of the device performance by controlling the nanopore size in graphene. The roles of graphene as an ion-blocking layer in the device structure were further supported by transmission electron microscopy, energy-dispersive X-ray spectroscopy, and atomistic simulations based on first-principles calculations.
Ye Zhou - One of the best experts on this subject based on the ideXlab platform.
-
Recent Advances of Flexible Data Storage Devices Based on Organic Nanoscaled Materials
Small, 2018Co-Authors: Li Zhou, Ye ZhouAbstract:The recent developments of a series of flexible organic Nonvolatile Data storage devices, from transistor based memory, including floating‐gate, charge‐trapping, and ferroelectric architectures, to resistive memory are summarized. The challenges and perspectives in this field are also discussed. The achievement of these fantastic Nonvolatile memory applications will set a new agenda for the design of novel Data storage.
-
hybrid flexible resistive random access memory gated transistor for novel Nonvolatile Data storage
Small, 2016Co-Authors: Li Zhou, Ye Zhou, Bo Chen, Chundong Wang, Jiaqing Zhuang, Hua ZhangAbstract:Here, a single-device demonstration of novel hybrid architecture is reported to achieve programmable transistor nodes which have analogies to flash memory by incorporating a resistive switching random access memory (RRAM) device as a resistive switch gate for field effect transistor (FET) on a flexible substrate. A high performance flexible RRAM with a three-layered structure is fabricated by utilizing solution-processed MoS2 nanosheets sandwiched between poly(methyl methacrylate) polymer layers. Gate coupling with the pentacene-based transistor can be controlled by the RRAM memory state to produce a nonprogrammed state (inactive) and a programmed state (active) with a well-defined memory window. Compared to the reference flash memory device based on the MoS2 floating gate, the hybrid device presents robust access speed and retention ability. Furthermore, the hybrid RRAM-gated FET is used to build an integrated logic circuit and a wide logic window in inverter logic is achieved. The controllable, well-defined memory window, long retention time, and fast access speed of this novel hybrid device may open up new possibilities of realizing fully functional Nonvolatile memory for high-performance flexible electronics.
-
Hybrid Flexible Resistive Random Access Memory‐Gated Transistor for Novel Nonvolatile Data Storage
Small, 2015Co-Authors: Ye Zhou, Li Zhou, Bo Chen, Chundong Wang, Jiaqing Zhuang, Hua ZhangAbstract:Here, a single-device demonstration of novel hybrid architecture is reported to achieve programmable transistor nodes which have analogies to flash memory by incorporating a resistive switching random access memory (RRAM) device as a resistive switch gate for field effect transistor (FET) on a flexible substrate. A high performance flexible RRAM with a three-layered structure is fabricated by utilizing solution-processed MoS2 nanosheets sandwiched between poly(methyl methacrylate) polymer layers. Gate coupling with the pentacene-based transistor can be controlled by the RRAM memory state to produce a nonprogrammed state (inactive) and a programmed state (active) with a well-defined memory window. Compared to the reference flash memory device based on the MoS2 floating gate, the hybrid device presents robust access speed and retention ability. Furthermore, the hybrid RRAM-gated FET is used to build an integrated logic circuit and a wide logic window in inverter logic is achieved. The controllable, well-defined memory window, long retention time, and fast access speed of this novel hybrid device may open up new possibilities of realizing fully functional Nonvolatile memory for high-performance flexible electronics.
Xiaohong Xu - One of the best experts on this subject based on the ideXlab platform.
-
Electric field induced simultaneous change of transport and magnetic properties in multilayered NiOx/Pt nanowires
Journal of Materials Chemistry C, 2020Co-Authors: Lanfang Wang, Xiaoli Li, Zhiyong Quan, Fang Wang, Xiaohong XuAbstract:Nanoscale manipulation of the transport and magnetic properties of a material offers a distinguished possibility for the development of novel multifunctional devices with ultra-small dimensions, high densities and low power consumption. This is highly desirable for promising applications in Nonvolatile Data storage. Here, a novel device with multilayered NiOx/Pt (x < 1) nanowire arrays as the switching matrix was constructed by a simple electrodeposition method combining a partial oxidization process. The device exhibits bipolar resistive switching behavior with free-forming, low switching voltage, and stable endurance properties. More importantly, its magnetoresistance and magnetic properties including saturated magnetization and coercivity can be simultaneously tuned during the resistive switching process. Both the Ni-rich region constructed through electric field-induced oxygen ion migration and the pre-existence of Ni nanoparticles in NiOx segments are responsible for the resistive switching and the corresponding modulation of the magnetoresistance and magnetic properties. This work provides a simple yet effective approach for the modulation of resistance and magnetization through electrical and magnetic control, which can provide a new way of designing a multifunctional magnetoelectric device.
-
Realization of resistive switching and magnetoresistance in ZnO/ZnO-Co composite materials
Scientific Reports, 2016Co-Authors: Xiaoli Li, Yanchun Li, Jie Li, Lanfang Wang, Xiaohong XuAbstract:Combining resistive switching and magnetoresistance in a system exhibits great potential for application in multibit Nonvolatile Data storage. It is in significance and difficulty to seek a material with resistances that can be stably switched at different resistance states modulated by an electrical field and a magnetic field. In this paper, we propose a novel electrode/ZnO/ZnO-Co/electrode device in which the storage layer combines a nanostructured ZnO-Co layer and a ZnO layer. The device exhibits bipolar resistive switching characteristics, which can be explained by the accumulation of oxygen vacancies due to the migration of oxygen ions by external electrical stimuli and the contribution of Co particles in the ZnO-Co layer. Moreover, the magnetoresistance effect at room temperature can be observed in the device at high and low resistance states. Therefore, through electrical and magnetic control, four resistance states are achieved in this system, presenting a new possibility towards enhancing Data densities by many folds.
Yan-xue Chen - One of the best experts on this subject based on the ideXlab platform.
-
Spin memristive magnetic tunnel junctions with CoO-ZnO nano composite barrier
Scientific Reports, 2014Co-Authors: Qiang Li, Ting Ting Shen, Yan Ling Cao, Yu Feng Tian, Shi Shou Kang, You Yong Dai, Shi-shen Yan, Ming Wen Zhao, Kun Zhang, Yan-xue ChenAbstract:The spin memristive devices combining memristance and tunneling magnetoresistance have promising applications in multibit Nonvolatile Data storage and artificial neuronal computing. However, it is a great challenge for simultaneous realization of large memristance and magnetoresistance in one nanoscale junction, because it is very hard to find a proper spacer layer which not only serves as good insulating layer for tunneling magnetoresistance but also easily switches between high and low resistance states under electrical field. Here we firstly propose to use nanon composite barrier layers of CoO-ZnO to fabricate the spin memristive Co/CoO-ZnO/Co magnetic tunnel junctions. The bipolar resistance switching ratio is high up to 90, and the TMR ratio of the high resistance state gets to 8% at room temperature, which leads to three resistance states. The bipolar resistance switching is explained by the metal-insulator transition of CoO(1-v) layer due to the migration of oxygen ions between CoO(1-v) and ZnO(1-v).
Jihang Lee - One of the best experts on this subject based on the ideXlab platform.
-
Tuning Ionic Transport in Memristive Devices by Graphene with Engineered Nanopores
ACS Nano, 2016Co-Authors: Jihang Lee, Kai Sun, Emmanouil Kioupakis, Chao Du, Wei D. LuAbstract:Memristors, based on inherent memory effects in simple two-terminal structures, have attracted tremendous interest recently for applications ranging from Nonvolatile Data storage to neuromorphic computing based on non-von Neumann architectures. In a memristor, the ability to modulate and retain the state of an internal variable leads to experimentally observed resistive switching (RS) effects. Such phenomena originate from internal, microscopic ionic migration and associated electrochemical processes that modify the materials' electrical and other physical properties. To optimize the device performance for practical applications with large-size arrays, controlling the internal ionic transport and redox reaction processes thus becomes a necessity, ideally at the atomic scale. Here we show that the RS characteristics in tantalum-oxide-based memristors can be systematically tuned by inserting a graphene film with engineered nanopores. Graphene, with its atomic thickness and excellent impermeability and chemical stability, can be effectively integrated into the device stack and can offer unprecedented capabilities for the control of ionic dynamics at the nanoscale. In this device structure, the graphene film effectively blocks ionic transport and redox reactions; thereby the oxygen vacancies required during the RS process are allowed to transport only through the engineered nanosized openings in the graphene layer, leading to effective modulation of the device performance by controlling the nanopore size in graphene. The roles of graphene as an ion-blocking layer in the device structure were further supported by transmission electron microscopy, energy-dispersive X-ray spectroscopy, and atomistic simulations based on first-principles calculations.
