Materials Today Electronics最新文献

Tetragonal zinc chalcogenide monolayers (TZCM) are emerging as interesting electronic materials with a direct band gap and relatively high carrier mobility. In this work, we report a theoretical investigation of electronic transport properties and photoelectric response properties of TZCM with gold contacts by density functional theory (DFT) and non-equilibrium Green's function (NEGF) methods. When there is no gate voltage applied, the current increases nonlinearly as bias voltage increases. Among the four proposed devices, the Au(100)/ZnS/Au(100) device has the best electronic transport performance and is most sensitive to the adjustment of bias voltage and gate voltage. The photocurrent calculation results indicate that the low-frequency oscillatory photocurrent of the Au(100)/ZnSe/Au(100) device in the high photon energy region may have potential applications in ultraviolet light-emitting diodes. The Au(100)/Zn₂SeS/Au(100) device has more stable photoelectric response and polarization sensitivity than the Au(100)/Zn₂SSe/Au(100) device. The Au(100)/TZCM/Au(100) devices exhibit considerable photocurrent and good extinction ratios. This work could pave the way for the future application of TZCM in the field of optoelectronics and so on.

Electrical switching of magnetization via spin-orbit torque is of great potential in fast, dense, energy-efficient nonvolatile magnetic memory and logic technologies. Recently, enormous efforts have been stimulated to investigate switching of perpendicular magnetization in van der Waals systems that have unique, strong tunability and spin-orbit coupling effect compared to conventional metals. In this review, we first give a brief, generalized introduction to the spin-orbit torque and van der Waals materials. We will then discuss the recent advances in magnetization switching by the spin current generated from van der Waals materials and summary the progress in the switching of van der Waals magnetization by the spin-orbit torque.

Reconfigurable field effect transistors are one of the most promising emerging device concepts for future computing systems, due to their dynamic p- and n-channel behavior. Over the past decade, there have been significant advances on electrical characteristics and circuit designs, but there are still many additional options to explore. In this letter, a disruptive common-channel reconfigurable filed effect transistor concept is presented experimentally for the first time. A cross-shape integrated nanowire structure is fabricated on a silicon-on-insulator wafer using top-down methods for higher reproducibility. The fabricated cross-shape reconfigurable field effect transistor is composed of a doping-free common channel with four independent silicided source and drain junctions, a silicon dioxide dielectric layer and four independent gates aligned on top of the silicide junctions. By assembling this unique common-channel structure, device level current routing was provided. A detailed comprehensive study of the cross-shape reconfigurable field effect transistor electrical characteristics are presented. The fabricated device demonstrates nearly equal transistor characteristics for each branch, which enables new complementary circuit designs to be introduced. We demonstrated an inverter and a multiplexer circuit both built from the same two transistors with enhanced functionality when compared to a single source configuration.

Combining functional soft materials with electrical impedance tomography is a promising method for developing continuum sensorized soft robotic skins with high resolutions. However, reconstructing the tactile stimuli from surface electrode measurements is a challenging ill-posed modelling problem, with FEM and analytic models facing a reality gap. To counter this, we propose and demonstrate a model-free superposition method which uses small amounts of real-world data to develop deformation maps of a soft robotic skin made from a self-healing ionically conductive hydrogel, the properties of which are affected by temperature, humidity, and damage. We demonstrate how this method outperforms a traditional neural network for small datasets, obtaining an average resolution of 12.1 mm over a 170 mm circular skin. Additionally, we explore how this resolution varies over a series of 15,000 consecutive presses, during which damages are continuously propagated. Finally, we demonstrate applications for functional robotic skins: damage detection/localization, environmental monitoring, and multi-touch recognition - all using the same sensing material.

In this study, the effect of rapid thermal annealing (RTA) on the electrical and optical properties of NiO/ β-Ga₂O₃ heterojunction diodes was investigated using capacitance-voltage, current-voltage, Deep Level Transient Spectroscopy (DLTS), Laplace DLTS, photoluminescence and micro-Raman spectroscopy techniques, and SILVACO-TCAD numerical simulator. The NiO is designed to be lowly-doped, allowing for the NiO full depletion at zero bias and the study of properties of β-Ga₂O₃ and its interface with NiO. Micro-Raman results revealed good agreement with the theoretical and experimental results reported in the literature. The photoluminescence intensity of the sample after RTA is five times higher than the fresh sample due to a rise in the density of gallium and oxygen vacancies (V_Ga + V_O) in the annealed β-Ga₂O₃ samples. The current-voltage characteristics showed that annealed devices exhibited a lower ideality factor at room temperature and higher barrier height compared with fresh samples. The DLTS measurements demonstrated that the number of electrically active traps were different for the two samples. In particular, three and one electron traps were detected in fresh samples and annealed samples, respectively. SILVACO-TCAD was used to understand the distribution of the detected electron E₂ trap (E_c-0.15 eV) in the fresh sample and the dominant transport mechanisms. A fairly good agreement between simulation and measurements was achieved considering a surface NiO acceptor density of about 1 × 10¹⁹ cm⁻³ and E₂ trap depth into the surface of β-Ga₂O₃ layer of about 0.220 µm and the effect of the most observed E_c-0.75 eV trap level in β-Ga₂O₃. These results unveil comprehensive physics in NiO/β-$G{a}_2{O}_3$heterojunction and suggest that RTA is an essential process for realizing high-performance NiO/β-$G{a}_2{O}_3$devices.

Magnetoplasmonics is an emerging interdisciplinary field that studies the interaction between magnetism and plasmonics, and has great promise for the development of novel optical, magnetic, and spintronic devices. The goal of this review is to provide a comprehensive overview of the current state-of-the-art in magnetoplasmonics, including the fundamentals, materials, and applications. The review first presents an introduction to the basic concepts of magnetoplasmonics, magneto-optical and plasmonic materials, and the various ways in which they can be combined to create novel hybrid systems. The review then examines the influence of surface plasmon resonances on the magneto-optical properties of a system as well as the achievement of balance of magneto-optical and surface plasmon properties to maximize the overall magnetoplasmonic properties. Selected major applications in biomedicine, biomedical technologies, optoelectronics and telecommunications are then discussed. Finally, it concludes with key challenges in the use of magnetoplasmonics in these applications, the need for new materials, new fabrication approaches, and further understanding to control the complex interactions between magnetism and plasmonics.

The layer-by-layer (LBL) fabrication of conjugated polymer (CPs) thin films while preserving their microstructural features by solution processing is highly desired for compact and flexible electronic circuits. However, it is cumbersome and challenging owing to the unavoidable damage to the underlying layers. To circumvent this issue, the unidirectional floating-film transfer method (UFTM) was utilized for the LBL fabrication of oriented CP thin films on the orthogonal liquid surfaces. Further, resistive bistable memory switches were fabricated by sandwiching a layer of metal nanostructures between the LBL-fabricated oriented CP thin films. The resistive switching phenomena were realized by utilizing the applied bias-dependent charge trapping, holding, and recombination on the available states at vacuum-deposited aluminum nanostructures. The effect of CP backbone conformation on the vertical charge transport was also analyzed via a comparative study of three thiophene-based polymers namely RR-P3HT, PBTTT, and PTB-7. It was revealed that CPs with relatively fewer hydrophobic side chains was more favorable for the facile vertical charge transport due to its preferred face-on conformation on the hydrophilic liquid substrate used in UFTM. It was demonstrated that a non-volatile bistable resistive memory switch fabricated using UFTM-processed oriented thin films of PTB-7 exhibited a remarkably high on-off ratio of 1.5 × 10⁶ with high durability.

The hafnia-based ferroelectric oxides with excellent negative-capacitance properties offer a great opportunity to develop high-performance integrated circuits. The nanosized multiphase distribution of Hf_0.5Zr_0.5O₂ (HZO) has a significant influence on its ferroelectric properties. Transmission electron microscope (TEM) with an atomistic resolution could establish the structure-property relationship and guide the performance improvement of HZO by identifying its phase structures. However, the high throughput TEM data and its complexity of interpretation make the quantitatively extracting the physical and chemical information from the TEM images challenging and low-efficiency. Here, we develop an automatic work flow for the TEM data analysis, which greatly enhances the efficiency of TEM data processing. By extracting the interest area and training the neural network with ResNet18, the accuracy of phase determination reaches 95.82% with low computational cost. Theoretical analysis is conducted to unveil the advantages of the ResNet18 network. The approach provided in this work could promote the quantitative analysis of the high-throughput TEM images and pave the way for future on-line analysis of the TEM image stream in real-time.

In this work, we present the synthesis of nanoscale heterostructures of sodium titanate nanotubes Na₂Ti₂O₅.H₂O (NaNT) decorated with N- and S- co-doped graphene quantum dots (NS-GQD) for quantum dots sensitized solar cells (QDSSC). The study was mainly focused on the structural, microstructural, electrical and optical characterization of these nanoscale heterostructures by means of X ray diffraction, transmission electron microscopy, atomic force microscopy, Raman, UV–vis and impedance spectroscopies. Our nanoscale heterostructures yielded a significant enhancement in the electric conductivity interpreted in terms of favorable interactions between the NS-GQD and the NaNT acting as proper connectors. Finally, our QDSSC prototype exhibits promising values for diffusion coefficient and recombination times as evidenced by means of impedance modulated photocurrent and photovoltage spectroscopies. Also, we consider that these materials could be further explored for electron transport layers applications in order to exploit the advantages regarding electron transport properties.