A Novel Method to Analyze the Relationship between Thermoelectric Coefficient and Energy Disorder of Any Density of States in an Organic Semiconductor.

In this work, a unified method is proposed for analyzing the relationship between the Seebeck coefficient and the energy disorder of organic semiconductors at any multi-parameter density of states (DOS) to study carrier transport in disordered thermoelectric organic semiconductors and the physical meaning of improved DOS parameters. By introducing the Gibbs entropy, a new multi-parameter DOS and traditional Gaussian DOS are used to verify this method, and the simulated result of this method can well fit the experiment data obtained on three organic devices. In particular, the impact of DOS parameters on the Gibbs entropy can also influence the impact of the energy disorder on the Seebeck coefficient.

A Novel Density of States (DOS) for Disordered Organic Semiconductors.

In this work, we proposed a novel theory of DOS for disordered organic semiconductors based on the frontier orbital theory and probability statistics. The proposed DOS has been verified by comparing with other DOS alternatives and experimental data, and the mobility calculated by the proposed DOS is closer to experimental data than traditional DOS. Moreover, we also provide a detailed method to choose the DOS parameter for better use of the proposed DOS.

Collective Transport for Nonlinear Current-Voltage Characteristics of Doped Conducting Polymers.

Origin of nonlinear transport phenomena in conducting polymers has long been a topic of intense controversies. Most previous knowledge has attributed the macroscopic nonlinear I-V characteristics to individual behaviors of elementary resistors in the network. In this Letter, we show via a systematic dimensionality-dependent transport investigation, that understanding the nonlinear transport in conducting polymers must include the collective transport effect in a percolation network.

Charge Trapping and Emission Properties in CAAC-IGZO Transistor: A First-Principles Calculations.

The c-axis aligned crystalline indium-gallium-zinc-oxide field-effect transistor (CAAC-IGZO FET), exhibiting an extremely low off-state leakage current (~10 A/μm), has promised to be an ideal candidate for Dynamic Random Access Memory (DRAM) applications. However, the instabilities leaded by the drift of the threshold voltage in various stress seriously affect the device application. To better develop high performance CAAC-IGZO FET for DRAM applications, it's essential to uncover the deep physical process of charge transport mechanism in CAAC-IGZO FET.

Surface-Doping-Induced Mobility Modulation Effect for Transport Enhancement in Organic Single-Crystal Transistors.

Molecular doping has conventionally been an effective way to improve the electrical-transport performances in organic field-effect transistors (OFETs), while corresponding mechanisms associated with specific doping techniques have been less investigated and discussed in detail. Here, based on ultrathin dinaphtho[2,3-b:2',3'-f]-thieno[3,2-b]thiophene (DNTT) single crystals, robust transconductance enhancements are realized in OFETs upon surface molecular doping realized via van der Waals epitaxially growing crystalline 1,3,4,5,7,8-hexafluoro-tetracyanonaphthoquinodimethane (F6TCNNQ) onto the single crystal's surface. It is proposed that it is the mobility modulation effect (MME) from the interactions between charge-transfer interface and gate electric field, that contributes to more weighted bulk carriers, and finally improves charge-transport performances.

High-Stability Memristive Devices Based on Pd Conductive Filaments and Its Applications in Neuromorphic Computing.

Memristive devices with high-density and high-speed performance have considerable potential for neuromorphic computing applications in data storage and artificial synapses. However, current memristive devices that are based on conductive filaments, such as silver, are unstable owing to the high mobility and low thermodynamic stability of the filaments. A high-quality SnSe film was deposited using the pulsed laser deposition technology, and high-performance Pd/SnSe/NSTO devices were fabricated.

A tied Fermi liquid to Luttinger liquid model for nonlinear transport in conducting polymers.

Organic conjugated polymers demonstrate great potential in transistors, solar cells and light-emitting diodes, whose performances are fundamentally governed by charge transport. However, the morphology-property relationships and the underpinning charge transport mechanisms remain unclear. Particularly, whether the nonlinear charge transport in conducting polymers is appropriately formulated within non-Fermi liquids is not clear.

Spike Encoding with Optic Sensory Neurons Enable a Pulse Coupled Neural Network for Ultraviolet Image Segmentation.

Drawing inspiration from biology, neuromorphic systems are of great interest in direct interaction and efficient processing of analogue signals in the real world and could be promising for the development of smart sensors. Here, we demonstrate an artificial sensory neuron consisting of an InGaZnO (IGZO)-based optical sensor and NbO-based oscillation neuron in series, which can simultaneously sense the optical information even beyond the visible light region and encode them into electrical impulses. Such artificial vision sensory neurons can convey visual information in a parallel manner analogous to biological vision systems, and the output spikes can be effectively processed by a pulse coupled neural network, demonstrating the capability of image segmentation out of a complex background.

Possible Luttinger liquid behavior of edge transport in monolayer transition metal dichalcogenide crystals.

In atomically-thin two-dimensional (2D) semiconductors, the nonuniformity in current flow due to its edge states may alter and even dictate the charge transport properties of the entire device. However, the influence of the edge states on electrical transport in 2D materials has not been sufficiently explored to date. Here, we systematically quantify the edge state contribution to electrical transport in monolayer MoS/WSe field-effect transistors, revealing that the charge transport at low temperature is dominated by the edge conduction with the nonlinear behavior.

A Review for Compact Model of Thin-Film Transistors (TFTs).

Thin-film transistors (TFTs) have grown into a huge industry due to their broad applications in display, radio-frequency identification tags (RFID), logical calculation, etc. In order to bridge the gap between the fabrication process and the circuit design, compact model plays an indispensable role in the development and application of TFTs. The purpose of this review is to provide a theoretical description of compact models of TFTs with different active layers, such as polysilicon, amorphous silicon, organic and In-Ga-Zn-O (IGZO) semiconductors.

Correction: A review of carrier thermoelectric-transport theory in organic semiconductors.

Correction for 'A review of carrier thermoelectric-transport theory in organic semiconductors' by Nianduan Lu et al., Phys. Chem.

Eliminating Negative-SET Behavior by Suppressing Nanofilament Overgrowth in Cation-Based Memory.

Negative-SET behavior is observed in various cation-based memories, which degrades the device reliability. Transmission electron microscopy results demonstrate the behavior is caused by the overgrowth of the conductive filament (CF) into the Pt electrode. The CF overgrowth phenomenon is suppressed and the negative-SET behavior is eliminated by inserting an impermeable graphene layer.

Super non-linear RRAM with ultra-low power for 3D vertical nano-crossbar arrays.

Vertical crossbar arrays provide a cost-effective approach for high density three-dimensional (3D) integration of resistive random access memory. However, an individual selector device is not allowed to be integrated with the memory cell separately. The development of V-RRAM has impeded the lack of satisfactory self-selective cells.

A review of carrier thermoelectric-transport theory in organic semiconductors.

Carrier thermoelectric-transport theory has recently become of growing interest and numerous thermoelectric-transport models have been proposed for organic semiconductors, due to pressing current issues involving energy production and the environment. The purpose of this review is to provide a theoretical description of the thermoelectric Seebeck effect in organic semiconductors. Special attention is devoted to the carrier concentration, temperature, polaron effect and dipole effect dependence of the Seebeck effect and its relationship to hopping transport theory.

Thermal crosstalk in 3-dimensional RRAM crossbar array.

High density 3-dimensional (3D) crossbar resistive random access memory (RRAM) is one of the major focus of the new age technologies. To compete with the ultra-high density NAND and NOR memories, understanding of reliability mechanisms and scaling potential of 3D RRAM crossbar array is needed. Thermal crosstalk is one of the most critical effects that should be considered in 3D crossbar array application.

High uniformity and improved nonlinearity by embedding nanocrystals in selector-less resistive random access memory.

The sneak path problem is one of the major hindrances for the application of high density 3D crossbar resistive random access memory (RRAM). For the selector-less RRAM devices, nonlinear (NL) current-voltage (I-V) characteristics are an alternative approach to minimize the sneak paths. In this work we have demonstrated metallic IrOx nanocrystal (IrOx-NC) based selector-less crossbar RRAM devices in an IrOx/AlOx/IrOx-NC/AlOx/W structure with very reliable hysteresis resistive switching of >10 000 cycles, stable multiple levels, and high temperature (HT) data retention.

Thermoelectric Seebeck effect in oxide-based resistive switching memory.

Reversible resistive switching induced by an electric field in oxide-based resistive switching memory shows a promising application in future information storage and processing. It is believed that there are some local conductive filaments formed and ruptured in the resistive switching process. However, as a fundamental question, how electron transports in the formed conductive filament is still under debate due to the difficulty to directly characterize its physical and electrical properties.

Nanoscale thermodynamic study on phase transformation in the nanocrystalline Sm2Co17 alloy.

The characteristics of phase transformation in nanocrystalline alloys were studied both theoretically and experimentally from the viewpoint of thermodynamics. With a developed thermodynamic model, the dependence of phase stability and phase transformation tendency on the temperature and the nanograin size were calculated for the nanocrystalline Sm(2)Co(17) alloy. It is thermodynamically predicted that the critical grain size for the phase transformation between hexagonal and rhombohedral nanocrystalline Sm(2)Co(17) phases increases with increasing temperature.

Crystal structure and magnetic properties of ultrafine nanocrystalline SmCo3 compound.

The single-phase ultrafine nanocrystalline SmCo(3) compound with a high coercivity of 33 kOe and a Curie temperature of 925 K was prepared using a simple and efficient method, which took advantages of the concurrent processes of nanocrystallization and densification during spark plasma sintering. The crystal structure of the nanocrystalline SmCo(3) compound was constructed. As compared with the conventional microcrystalline SmCo(3) compound, a large axial ratio c/a = 4.

Preparation and characterization of dysprosium (Dy) ultrafine nanocrystalline structures.

By combining the inert-gas condensation with the SPS technology in an entirely closed system with the oxygen concentration below 0.5 ppm, the pure Dy bulk with the ultrafine nanocrystalline structure has been prepared. Thus a novel and efficient route of preparing nano rare-earth metals, as well as metallic nanomaterials that are highly reactive in the air, is proposed.