- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
An optically-gated transistor comprised of amorphous M+Ge2Se3 (M=Cu, Sn) for accessing and continuously programming a memristor
摘要： We demonstrate that a device comprised of sputtered amorphous chalcogenide Ge2Se3/M+Ge2Se3 (M = Sn or Cu) alternating layers, functions as an optically-gated transistor (OGT) and can be used as an access transistor for a memristor memory element. This transistor has only two electrically connected terminals (source and drain), with the gate being optically controlled, thus allowing the transistor to operate only in the presence of light (385 – 1200 nm). The switching speed of the OGTs is less than 15 μs. The OGT is demonstrated in series with a Ge2Se3+W memristor, where we show that by altering the light intensity on the OGT gate, the memristor can be programmed to a continuous range of non-volatile memory states using the saturation current of the OGT as a programming compliance current. By having a continuous range of non-volatile states, one memory cell can potentially achieve 2n levels. This high density, combined with optical programmability, enables hybrid electronic/photonic memory.
关键词： access transistor,chalcogenide,resistive RAM,optoelectronic,selector,amorphous,memristor
更新于2025-09-23 15:23:52
-
Performance-Enhancing Selector via Symmetrical Multilayer Design
摘要： Two-terminal selectors with high nonlinearity, based on bidirectional threshold switching (TS) behaviors, are considered as a crucial element of crossbar integration for emerging nonvolatile memory and neuromorphic network. Although great efforts have been made to obtain various selectors, existing selectors cannot fully satisfy the rigorous standard of assorted memristive elements and it is in great demand to enhance the performance. Here, a new type of Ag/TaOx/TaOy/TaOx/Ag (x < y) selector based on homogeneous trilayered oxides is developed to attain the required parameters including bidirectional TS operation, a large selectivity of ≈1010, a high compliance current up to 1 mA, and ultralow switching voltages under 0.2 V. Tunable operation voltages can be realized by modulating the thickness of inserted TaOy. All-TaOx-based integrated 1S1R (one selector and one memristor) cells, prepared completely by magnetron sputtering and no need of a middle electrode, exhibit a nonlinear feature, which is quite characteristic for the crossbar devices, avoiding undesired crosstalk current issues. The tantalum-oxide-based homojunctions offer high insulation, low ion mobility, and rich interfaces, which is responsible for the modulation of Ag conductive filaments and corresponding high-performance cation-based selector. These findings might advance practical implementation of two-terminal selectors in emerging memories, especially resistive random access memories.
关键词： conductive filaments,1S1R,multilayers,threshold switching,TaOx,selector
更新于2025-09-23 15:23:52
-
Research on Temperature Effect in Insulator-Metal Transition Selector Based on NbO? Thin Films
摘要： In this paper, the NbOx, which was regarded as a promising material based on its insulator–metal transition (IMT) effects, was applied as the switching layer of the device. The threshold switching characteristics were comprehensively investigated with particular emphasis on temperature dependence. The conduction mechanism for high-resistance state (HRS) was ?tted and veri?ed to be Schottky emission. With the increase in temperature, the ?tting results demonstrated that the Schottky barrier decreased, leading to a reduction in the resistance of HRS. Furthermore, according to Fourier’s law of heat conduction, the ?uctuation range of temperature was smaller, causing a narrow distribution of the threshold voltage as the operating temperature increased. In addition, the increasing temperature caused high energy of electrons, which would induce an IMT more easily, leading to a lower threshold voltage. This paper provided the promise for improving the thermal stability of selected devices.
关键词： selector,Insulator–metal transition (IMT),threshold switching (TS),Schottky emission
更新于2025-09-23 15:21:01
-
Temperature dependent structural evolution and crystallization properties of thin Ge<sub>15</sub>Te<sub>85</sub> film revealed by in situ resistance, X-Ray diffraction and scanning electron microscopic studies
摘要： Chalcogenide-based Ge15Te85 thin films have recently been explored for Ovonic threshold switching (OTS) selector devices for vertically stackable cross-point memory applications. Despite reasonable understanding over its crystallization kinetics and threshold switching properties, the structural stability and morphological acquaintance at elevated temperatures remain key challenges. In this paper, we investigate the thermal stability, surface morphology and local structure of as-deposited amorphous Ge15Te85 thin film starting from room temperature up to 325 °C. Our experimental results reveal that upon heating, the de-vitrification is initiated in the form of localized segregation of Te atoms at 120 °C, followed by crystallization of Te at ~ 220 °C and GeTe at ~ 263 °C as corroborated by temperature- dependent measurements of electrical resistance, X-ray diffraction and scanning electron microscopic studies. Furthermore, the crystalline areas of these films are characterized by the fine-grained morphology, which clearly distinguishes the segregation of crystallization of Te and GeTe microstructures. These findings elucidate a deeper understanding of the multi-phase crystallization process through morphological evidence, which will be useful towards optimization of materials for Ovonic Threshold Switch (OTS) selector applications.
关键词： Chalcogenide thin films,phase change material,OTS Selector,Scanning electron microscopy,Ge15Te85
更新于2025-09-19 17:13:59
-
[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Aperture-coupled Plasmonic Voltage Tunable Filter Based on Asymmetric Micro-ring Resonators
摘要： This paper presents a novel mixed-signal low-power dual-band square/triangular waveform generator (WFG) chip with a wide low-frequency tuning range for medical bio-electric stimulation therapy. It consists of a relaxation oscillator comprising a hysteresis Schmitt trigger and a timing integrator, along with frequency divider (FD) stages and path selector output for driving an electrode from 16 selectable channels. It was fabricated using Global Foundries 8RF-DM 130-nm CMOS process with a supply voltage of ±1 V for the oscillator and +1 V for logic circuits. The WFG provides an output of around 1.5 Vp–p at a nominal low oscillation frequency of 17 kHz using small-size on-chip passive components of values 10 kΩ and 10 pF. The WFG core (band I) can be tuned in the range 6.44–1003 kHz through bias current adjustment, while a lower frequency (band II) in the range 0.1 Hz–502 kHz can be provided digitally through a ÷2 stage. The power consumption was only 0.457 mW for the WFG and 2.1 mW for the FD circuit while occupying a total silicon area of only 18 426 μm2.
关键词： hysteresis Schmitt trigger,low-frequency,multiplexer,path selector,frequency divider,low-power,Waveform generator
更新于2025-09-19 17:13:59
-
Scenarios of local spectral property and multifunctional spin selecting for a triple quantum dot molecule: How do the bonding and antibonding orbitals contribute to the spin currents?
摘要： Molecular electronic device is considered as a promising candidate for next generation electronic component, where the basic challenge involves understanding the charge and spin transports through molecular objects. In this paper, with the help of the sophisticated numerical renormalization group technique, we study theoretically the spin selective transport in a parallel triple quantum dot molecular device pierced by a local magnetic field along z axis. Based on simplified parameters of real molecular system, we find such device acts as a multi-functional spin selector when the inter-molecule tunneling couplings are asymmetric, including two 100% polarized spin-up summits, and one 100% spin-down summit in the linear conductance. We show in detail the local density of states for the bonding and anti-boding orbitals, and attribute the spin selection to the orbital polarized Coulomb blockade effect. We demonstrate our numerical results are consistent with those estimated by the analytical techniques, including the Friedel sum rule and the energy level crossings of the isolated orbitals.
关键词： Coulomb blockade effect,Multifunctional spin selector,Triple quantum dot molecule,Numerical renormalization group technique,Molecular electronics device
更新于2025-09-12 10:27:22
-
[IEEE 2018 International Conference on Information , Communication, Engineering and Technology (ICICET) - Pune, India (2018.8.29-2018.8.31)] 2018 International Conference on Information , Communication, Engineering and Technology (ICICET) - Simulation of Dual Axis Solar Tracking System
摘要： Photovoltaic (PV) panel is used to convert solar energy into electricity. Increase in collection of solar radiations by Photovoltaic (PV) panel rises electricity output from it. By tracking the movement of sun, PV panel can be always positioned in such a way that it can collect maximum amount of solar radiations. This paper presents MATLAB simulation model of Dual Axis Solar Tracking System (DASTS), in which the PV panel can be rotated along two axes of rotation to track both east to west and north to south movement of sun. East to west angle selector and north to south angle selector provide particular angles to PV panel according to particular illuminance level at particular time of the day to rotate and position PV panel in such a way that it can always faces the sun. Readings of voltage, current and power obtain from PV panel with Dual Axis Solar Tracking System are taken at different times of the day and they are compared with readings of voltage, current and power obtain from fixed PV panel at different times of the day.
关键词： Modeling and simulation,Photovoltaic (PV) module,Angle selector
更新于2025-09-10 09:29:36
-
Chemical Vapor Deposited Vanadium Pentoxide Nanosheets with Highly Stable and Low Switching Voltages for Effective Selector Devices
摘要： Recently, attempts to overcome the physical limits of memory devices have led to the development of promising materials and architectures for next-generation memory technology. The selector device is one of the essential ingredients of high-density stacked memory systems. However, complicated constituent deposition conditions and thermal degradation are problematic, even with effective selector device materials. Herein, we demonstrate the highly stable and low threshold voltages of vanadium pentoxide (V2O5) nanosheets synthesized by facile chemical vapor deposition, which have not been previously reported on the threshold switching properties. The electrons occupying trap sites in poly-crystalline V2O5 nanosheet contribute to the perfectly symmetric threshold switching feature at the bias polarity and low threshold voltages in V2O5, confirmed by high-resolution transmission electron microscopy measurements. Furthermore, we find an additional PdO interlayer in V2O5 nanodevices connected with a Pd/Au electrode after thermal annealing treatment. The PdO interlayer decreases the threshold voltages, and the Ion/Ioff ratio increases because of the increased trap density of V2O5. These studies provide insight into V2O5 switching characteristics, which can support low power consumption in non-volatile memory devices.
关键词： nanosheets,selector devices,vanadium pentoxide,threshold switching,thermal annealing treatment
更新于2025-09-10 09:29:36
-
[IEEE 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Saint Petersburg, Russia (2018.10.22-2018.10.23)] 2018 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - S-Band Microstrip Bandpass Filter Design Based on New Approach to Coupling Coefficients Calculation
摘要： In this paper, a new approach to bandpass filter design, based on coupling coefficients calculation, introduced in [1], is experimentally verified. S-band (2.7 – 3.1 GHz bandwidth) microstrip bandpass filters of several four-resonator structures for pre-selectors of active phase array radar systems are designed, produced and measured. A conventional parallel-coupled filter is produced and measured for comparison. Measurement results confirm good performance of used approach.
关键词： S-band,open-loop resonator,bandpass filter,microstrip,coupled resonators,active phase array radar,pre-selector
更新于2025-09-04 15:30:14