Materials Today Electronics最新文献

The 2D Janus structure, an important derivative of 2D materials, exhibits distinct properties and significant potential in nanodevices. In this study, we focused on the recently synthesized 2D transition metal carbo-chalcogenide Nb₂S₂C [Adv. Mater. 34, 2200574 (2022)]. Through first-principles calculations, we designed five stable 2D Janus Nb₂SXC (X=O, Se, F, Cl, and Br) structures by substituting the top-layer sulfur atoms with X atoms. Both the intrinsic 2D Nb₂S₂C and the five 2D Janus Nb₂SXC structures display promising superconductivity, with an estimated T_c ranging from 1.35 to 12.66 K. The superconductivity is primarily attributed to the strong coupling between the vibration modes of the transverse acoustic branch and the electrons of Nb atoms. Further analysis reveals the significant role of electronegativity in the superconductivity of X elements. For X elements within the same main group, a larger electronegativity corresponds to stronger ionic Nb-X bonds, resulting in further softening of the transverse acoustic mode and enhanced superconductivity. These findings emphasize the crucial contribution of ionic Nb-X bonding in determining the T_c of the 2D Janus Nb₂SXC system, thus expanding the design possibilities for this wide range of superconducting materials.

LaMnO_3+δ (LMO) perovskite is a very interesting candidate for Valence Change Memories due to its flexible stoichiometry, accommodated through the Mn⁺³/Mn⁺⁴ equilibrium, at the origin of significant resistivity changes. Here, the successful combination of a LMO layer, with a top active TiN electrode and a bottom inert Pt electrode, is presented. The manganite layer is integrated on silicon-based substrates in the form of a polycrystalline film. By comparing the memristive behavior of these TiN/LMO/Pt devices with Au/LMO/Pt devices prepared on the same film, the essential role of the active oxygen electrode is put in evidence. TiN/LMO/Pt memristive devices show optimized performance, operating in both sweep and pulse mode, with the capability of cycling more than a hundred times and showing good retention. Furthermore, a simple phenomenological model describing the memristive behavior of the devices is also presented.

In this paper, a bio-based and biocompatible polymer, Cellulose Laurate (CL), is proposed for flexible radio-frequency (RF) electronics. The synthesis of CL films together with their characterizations (chemical, thermal, mechanical and dielectric) are presented. The results obtained allow considering this material for RF flexible applications as a possible alternative to petrosourced substrates. Therefore, CL has been used to fabricate a flexible patch antenna that operates in an industrial, scientific and medical (ISM) frequency band. The central frequency selected is 2.45 GHz. The antenna fabrication process is based on the combination of laser structuring and the use of copper adhesive tape. Measurements of the antenna reflection coefficient and radiation patterns show that CL is a good candidate as a RF substrate. Furthermore, it is demonstrated that the antenna performance is only slightly impacted under bending conditions.

2D materials, specifically transition metal dichalcogenides (TMDs), have gained massive attention for their potential use in high-integration memory technologies due to their exceptional carrier transport, atomically thin structure, and superior physical and electronic properties. High-density memory processors and complex hardware neural architectures based on TMDs have been developed and shown to have exceptional memory properties, making them a potential competitor to conventional Si technology. However, TMDs are still facing challenges with achieving high yields at high-density levels when compared to Si-based semiconductor technology. This review article covers the synthesis methods, memory device structures, high-volume circuits, and neuromorphic computing of TMD materials. We briefly discuss a plethora of synthesis methods that are utilized to achieve large-area uniform distribution in the fabrication of memory arrays. Various memory device architectures based on two-terminal and three-terminal designs are introduced, offering comprehensive prospects for utilizing TMDs in neuromorphic computing and developing energy-efficient and low-power neural networks for complex computational tasks beyond conventional Si-based architecture. Finally, the potential and challenges of utilizing TMDs in neuromorphic circuits are briefly discussed, including perspectives on system architecture and performance, synaptic functionalities, implementing ANN algorithms, and applications to artificial intelligence at high-density levels.

Anisotropy is an intrinsic property in crystals with low structural symmetry, and such well-textured materials usually show distinct electronic transport and optical properties along different lattice orientations, offering wide applications in electronic and photonic devices. As a typical low-symmetry materials, crystalline GeSe with orthorhombic structure shows large electric and optical anisotropies. In this work, we take advantage of the anisotropic mass transport and filamentary growth of Ag ions on the GeSe surface to fabricate planar memristive devices which show directional memory and transient switching phenomena. The anisotropic switching behaviors stem from the distinct morphology of metallic filaments that are directionally dependent on the mobility of ions, e.g., ions diffusing along the low-barrier direction tend to form stark conductive channels while those with low mobility only entail slim and weak dendrites, which have been clearly observed under electronic microscopy. The functionality could be utilized to mimic various synaptic events, such as long-term memory enabled by stable conductive channels and short-term memory by the spontaneous rupture of weak filaments, all implemented in one physical device. Two integration schemes based on the anisotropic devices are designed and demonstrated for different application scenarios, paving the way for its applications in multifunctional brain-inspired computing systems.

Printed electronics has enabled fabrication of electronic components and devices with low cost and more manufacturing and design freedom. This manufacturing technique has been successfully employed as a complementary fabrication approach to conventional nanolithography and microfabrication processes to create flexible and stretchable electronics. Fluoropolymers are crucial components in electronic devices and components, owing to their piezoelectric, triboelectric, pyroelectric, ferroelectric, and dielectric properties. In this research, we report fabrication of an inkjet-printed piezoelectric sensor based on poly (vinylidenefluoride trifluoroethylene) (PVDF-TrFE) and amine functionalized graphene oxide (AGO) for biomedical monitoring. The piezoelectric inkjet ink was obtained by optimizing the fluid mechanic properties based on Reynold and Weber numbers. The inkjet-printed freestanding film was characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), wide-angle X-Ray scattering (WAXS), and differential scanning calorimetry (DSC). The piezoelectric sensor was fabricated by deposition of silver electrodes on each side of the piezoelectric film, followed by wiring and encapsulation. The sensor was subjected to an electric field of 1500 kV/cm to align the internal dipoles and induce net polarization. The fabricated flexible piezoelectric sensor was employed for monitoring biomedical signals such as finger tapping, joint bending, and swallowing. The sensor demonstrated outstanding sensitivity of 0.1 V/kPa and excellent repeatability and stability over 1000 cycles.

P-type copper(I) thiocyanate (p-CuSCN) semiconductor materials have attracted a great deal of attention in the application for microsystems and optoelectronic engineering. Major challenge is in the development of advanced fabrication/growth techniques and resultant high-efficiency devices. Herein, in situ grown p-CuSCN film with different morphology are successfully achieved on flexible Cu foil by the simple solid-liquid interface reaction, which displays excellent UV photoresponse due to effective charge transport, thereby contributing to the large-area fabrication technique and the high-performance operation. The self-powered, highly sensitive and flexible NGQDs/CuSCN heterojunction device shows the ultrahigh photoresponsivity of 1.6 A/W and detectivity of 0.8 × 10¹² Jones at 3 V bias under 360 nm illumination, and the ultrafast photoresponse speed (T_r= 10 µs, T_d=0.6 ms), with relatively stable performance under bending cycles. The results provides an easy-processing and promising route to fabricate large-area p-CuSCN with remarkable optoelectronic performance, which opens up a new avenue on more novel works for the material design in practical photodetection.

Hybrid magnonics is an emerging research area focusing on various types of interactions between magnons (quantized collective spin excitations) and other information carriers, which has found broad practical applications ranging from high-precision magnetometry and thermometry to quantum transduction and neuromorphic computing. In this paper we review different types of hybrid magnonic devices, and the materials that are commonly used in each device type. We also discuss recent trends in the exploration of new materials and interaction mechanisms, and future research challenges and opportunities.

PEDOT:PSS-based smart electrochromic materials shows fast, real-time and efficient reversible color change due to redox process under influence of electric field. The color changes can directly carry readable visual information by the naked human eyes, showing promising applications in smart display, health monitoring, and energy storage. In this perspective, we summarize the recent progress of PEDOT:PSS-based electrochromic materials and their applications in wearable devices. We start with the electrochromic mechanism, synthesis and properties of various PEDOT:PSS complexes. Flexible and stretchable electrochromic devices, as well as their typical applications are then explored. Finally, we provide an overview of the current challenges and future perspectives for the development of advanced materials engineering and devices application.

Presence of coherent ‘resonant’ tunneling in quantum dot (zero-dimensional) - quantum well (two-dimensional) heterostructure is necessary to explain the collective oscillations of average electrical polarization of excitonic dipoles over a macroscopically large area. This was measured using photo excited capacitance as a function of applied voltage bias. Resonant tunneling in this heterostructure definitely requires momentum space narrowing of charge carriers inside the quantum well and that of associated indirect excitons, which indicates bias dependent ‘itinerant’ Bose-Einstein condensation of excitons. Observation of periodic variations in negative quantum capacitance points to in-plane coulomb correlations mediated by long range spatial ordering of indirect, dipolar excitons. Enhanced contrast of quantum interference beats of excitonic polarization waves even under white light and observed Rabi oscillations over a macroscopically large area also support the presence of density driven excitonic condensation having long range order. Periodic presence (absence) of splitting of excitonic peaks in photocapacitance spectra even demonstrate collective coupling (decoupling) between energy levels of the quantum well and quantum dots with applied biases, which can potentially be used for quantum gate operations. All these observations point to experimental control of macroscopically large, quantum state of a two-component Bose-Einstein condensate of excitons in this quantum dot - quantum well heterostructure. Therefore, in principle, millions of two-level excitonic qubits can be intertwined to fabricate large quantum registers using such hybrid heterostructure by controlling the local electric fields and also by varying photoexcitation intensities of overlapping light spots.