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Engineering of carbon-based superlight spin filter with negative differential resistance
摘要： Based on density functional theory and non-equilibrium Green’s function, we investigate the edge hydrogenation and oxidation effects on the spin transport of devices consisting of a zigzag C2N nanoribbon (ZC2NNR) embedded in zigzag graphene nanoribbons in parallel (P) and antiparallel (AP) spin configurations. The results show that device with edge hydrogenation exhibits dual spin filtering effect in AP spin configuration and obvious negative differential resistance in both P and AP spin configuration. By substituting oxygen for hydrogen as passivation atoms of ZC2NNR, the spin filtering efficiency is as high as 100% in the P spin configuration, and the negative differential resistance is largely enhanced with a peak to valley ratio in excess of 4×103. Our theoretical studies suggest that zigzag C2N nanoribbon modulated by edge substitution has great potential in the design of future multifunctional spin devices.
关键词： Negative Differential Resistance,Edge modification,Spin filtering effect,Zigzag C2N nanoribbon
更新于2025-09-23 15:23:52
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Semimetallicity and Negative Differential Resistance from Hybrid Halide Perovskite Nanowires
摘要： In the rapidly progressing field of organometal halide perovskites, the dimensional reduction can open up new opportunities for device applications. Herein, taking the recently synthesized trimethylsulfonium lead triiodide (CH3)3SPbI3 perovskite as a representative example, first-principles calculations are carried out and the nanostructuring and device application of halide perovskite nanowires are studied. It is found that the 1D (CH3)3SPbI3 structure is structurally stable, and the electronic structures of higher-dimensional forms are robustly determined at the 1D level. Remarkably, due to the face-sharing [PbI6] octahedral atomic structure, the organic ligand-removed 1D PbI3 frameworks are also found to be stable. Moreover, the PbI3 columns avoid the Peierls distortion and assume a semimetallic character, contradicting the conventional assumption of semiconducting metal-halogen inorganic frameworks. Adopting the bundled nanowire junctions consisting of (CH3)3SPbI3 channels with sub-5 nm dimensions sandwiched between PbI3 electrodes, high current densities and large room-temperature negative differential resistance (NDR) are finally obtained. It will be emphasized that the NDR originates from the combination of the near-Ohmic character of PbI3-(CH3)3SPbI3 contacts and a novel NDR mechanism that involves the quantum-mechanical hybridization between channel and electrode states. This work demonstrates the great potential of low-dimensional hybrid perovskites toward advanced electronic devices beyond actively pursued photonic applications.
关键词： semimetals,halide perovskite nanowires,first-principles calculations,negative differential resistance
更新于2025-09-23 15:22:29
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S-Type Negative Differential Resistance in Semiconducting Transition-Metal Dichalcogenides
摘要： Current-controlled (also known as “S-type”) negative differential resistance (NDR) is of crucial importance to many emerging applications including neuromorphic computing and high-density memristors integration. However, the experimental realization of S-type NDR based on conventional mechanisms poses demanding requirements on materials, which greatly limits their potential applications. Here, it is experimentally identified that semiconducting transition-metal dichalcogenides (TMDs) can host a bipolar S-type NDR devices. Theoretical simulations indicate that the origin of the NDR in these devices arises from a thermal feedback mechanism. Furthermore, the potential applications of TMD-based S-type NDR device in signal processing and neuromorphic electronics are demonstrated.
关键词： transition-metal dichalcogenides,signal processing,negative differential resistance,self-oscillating circuits,neuron spikes
更新于2025-09-23 15:22:29
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Effects of different tailoring graphene electrodes on the rectification and negative differential resistance of molecular devices
摘要： The electronic transport properties of oligo p-phenylenevinylene (OPV) molecule sandwiched with symmetrical or asymmetric tailoring graphene nanoribbons (GNRs) electrodes are investigated by nonequilibrium Green’s function in combination with density functional theory. The results show that different tailored GNRs electrodes can modulate the current–voltage characteristic of molecular devices. The rectifying behavior can be observed with respect to electrodes, and the maximum rectification ratio can reach to 14.2 in the asymmetric AC–ZZ GNRs and ZZ–AC–ZZ GNRs electrodes system. In addition, the obvious negative differential resistance can be observed in the symmetrical AC-ZZ GNRs system.
关键词： negative differential resistance,Graphene nanoribbons electrodes,nonequilibrium Green’s function method,rectifying behavior
更新于2025-09-23 15:21:01
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Negative Differential Resistance and Hysteresis in Selfa??Assembled Nanoscale Networks with Tunable Moleculea??toa??Nanoparticle Ratios
摘要： Electronic transport is investigated through self-assembled benzenedithiol–gold nanoparticle networks with tunable molecule-to-particle ratios (1:5–50:1) deposited between planar electrodes. Two-terminal current–voltage measurements of the networks display linear behavior at low bias, which is described using a circuit model that accounts for different network morphologies, tunable via molecule-to-nanoparticle ratio, and defects. At larger biases, nonlinear negative differential resistance and hysteresis behavior are observed for different molecular concentrations, which can be attributed to a combination of ?eld-assisted tunneling and charge trapping occurring in the nanoscale networks. The directed self-assembly of benzenedithiol–metal nanoparticle molecular electronic networks is suggested for molecular integrated circuits in applications such as memory, switching, hardware security, and computing.
关键词： molecules,electronic transport,self-assembly,negative differential resistance,nanoparticles
更新于2025-09-23 15:19:57
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Remarkable negative differential resistance and perfect spin-filtering effects of the indium triphosphide (InP <sub/>3</sub> ) monolayer tuned by electric and optical ways
摘要： Fully spin-polarized current and negative differential resistance (NDR) are two important electronic transport properties for spintronic nanodevices based on two-dimensional materials. Here, we describe both the electric and optical tuning of the spin-polarized electronic transport properties of the indium triphosphide (InP3) monolayer, which is doped with Ge atoms, by using quantum transport calculations. The spin degeneration of the InP3 monolayer is lifted due to the doping of Ge atoms. By applying a small bias voltage, a fully spin-polarized current can be obtained along both the armchair and zigzag directions. Moreover, a remarkable NDR is observed for the current along the zigzag direction, which shows a huge peak-to-valley ratio of 3.1 (cid:2) 103, while in the armchair direction, a lower peak-to-valley ratio of 5.5 is obtained. Alternatively, a fully spin-polarized photocurrent can also be generated under the illumination of linearly-polarized light by tuning either the photon energy or the polarization angle.
关键词： spin-polarized current,negative differential resistance,InP3 monolayer,quantum transport calculations,Ge doping,spintronic nanodevices
更新于2025-09-23 15:19:57
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Electromodulation of the Negative Differential Resistance in an AlGaAs/GaAs Resonant Tunneling Diode
摘要： In this work, we investigate the impact of the width of the AlGaAs right barrier and the doping concentration in the contact layers on the negative differential resistance (NDR) and the device performance of a double-barrier AlGaAs/GaAs resonant tunneling diode (RTD). Our simulation is performed using a non-equilibrium Green's formalism (NEGF). The obtained results show that increasing the width Lb2 of the right barrier, strongly reduces the peak-to-valley current ratio (PVCR. Especially, it reduces from 2.5 for symmetric RTD AlGaAs (5 nm) / GaAs (5 nm) to 1.1 when the right barrier AlGaAs is equal to 8 nm. Our findings show that a specific width of the right barrier Lb2 = 9 nm exists for which the NDR disappears completely. In addition, an increase in the doping concentration in the contact layers is found to reduce the (PVCR) and, consequently, the (NDR). These results open the door for designing resonant tunneling diodes with suitable negative differential resistances. The simulation of the RTD is performed with the use of Nanohub tools which confirms the various results presented in this paper.
关键词： Schrodinger equation,Resonant tunneling diode,Peak to valley ratio,Current-voltage characteristics,Negative differential resistance
更新于2025-09-19 17:15:36
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Origin of Current‐Controlled Negative Differential Resistance Modes and the Emergence of Composite Characteristics with High Complexity
摘要： Current-controlled negative differential resistance has significant potential as a fundamental building block in brain-inspired neuromorphic computing. However, achieving the desired negative differential resistance characteristics, which is crucial for practical implementation, remains challenging due to a lack of consensus on the underlying mechanism and design criteria. Here, a material-independent model of current-controlled negative differential resistance is reported to explain a broad range of characteristics, including the origin of the discontinuous snap-back response observed in many transition metal oxides. This is achieved by explicitly accounting for a non-uniform current distribution in the oxide film and its impact on the effective circuit of the device rather than a material-specific phase transition. The predictions of the model are then compared with experimental observations to show that the continuous S-type and discontinuous snap-back characteristics serve as fundamental building blocks for composite behavior with higher complexity. Finally, the potential of our approach is demonstrated for predicting and engineering unconventional compound behavior with novel functionality for emerging electronic and neuromorphic computing applications.
关键词： negative differential resistance,neuromorphic computing,threshold switching,nonlinear transport,nanoelectronics
更新于2025-09-19 17:13:59
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Current Localization and Redistribution as the Basis of Discontinuous Current Controlled Negative Differential Resistance in NbO <i> <sub/>x</sub></i>
摘要： Devices exploiting negative differential resistance (NDR) are of particular interest for analog computing applications, including oscillator-based neural networks. These devices typically exploit the continuous S-shaped current–voltage characteristic produced by materials with a strong temperature-dependent electrical conductivity, but recent studies have also highlighted the existence of a second, discontinuous (snap-back) characteristic that has the potential to provide additional functionality. The development of devices based on this characteristic is currently limited by uncertainty over the underlying physical mechanism, which remains the subject of active debate. In situ thermoreflectance imaging and a simple model are used to finally resolve this issue. Specifically, it is shown that the snap-back response is a direct consequence of current localization and redistribution within the oxide film, and that material and device dependencies are consistent with model predictions. These results conclusively demonstrate that the snap-back characteristic is a generic response of materials with a strong temperature-dependent conductivity and therefore has the same physical origin as the S-type characteristic. This is a significant outcome that resolves a long-standing controversy and provides a solid foundation for engineering functional devices with specific NDR characteristics.
关键词： brain-inspired computing,negative differential resistance,niobium oxide,thermoreflectance imaging,transition metal oxides
更新于2025-09-11 14:15:04
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Repeatable Room Temperature Negative Differential Resistance in AlN/GaN Resonant Tunneling Diodes Grown on Sapphire
摘要： Resonant tunneling diodes (RTDs) are candidates for high power terahertz oscillators, and form the basis for understanding the quantum confinement and vertical transport in quantum structures such as quantum cascade lasers and quantum cascade detectors. In this work, repeatable negative differential resistance (NDR) is achieved in AlN/GaN RTDs grown on sapphire substrate by plasma-assisted molecular-beam epitaxy. Two reproducible NDR regions sequentially following two preresonance replicas are demonstrated at room temperature. A current region exhibiting negative correlation with temperature and oscillation-like features is first identified under reverse bias, which is interpreted as a combined contribution of weak resonant tunneling channels through different bound states in the well. The revealed peak-to-valley current ratio ranges from 1.1 to 1.8, and peak current density ranges from 5 to 164 kA cm?2. Using an analytic model, resonant tunneling transports in both bias directions are quantitatively characterized and show good agreements with experiment results, demonstrating the capability of accurate quantum transport control using III-nitride grown on sapphire substrate. The findings will promote the implementation of low cost III-nitride monolithic microwave circuits and resonant tunneling structures based on sapphire, SiC, and even silicon substrates.
关键词： sapphire substrate,AlN/GaN resonant tunneling diodes,repeatable negative differential resistance
更新于2025-09-10 09:29:36