Highlights
Based on the benefits of two-dimensional (2D) transition metal chalcogenides (TMC) materials, the operating concepts and basics of memristors for neuromorphic computing are introduced.
The ...prospects of 2D TMC materials and heterostructures are reviewed, as well as the state-of-the-art demonstration of 2D TMCs-based memristors for neuromorphic computing applications.
The most recent advances, current challenges, and future prospects for the manufacture and characterization of memristive neuromorphic devices based on 2D TMCs are discussed.
Two-dimensional (2D) transition metal chalcogenides (TMC) and their heterostructures are appealing as building blocks in a wide range of electronic and optoelectronic devices, particularly futuristic memristive and synaptic devices for brain-inspired neuromorphic computing systems. The distinct properties such as high durability, electrical and optical tunability, clean surface, flexibility, and LEGO-staking capability enable simple fabrication with high integration density, energy-efficient operation, and high scalability. This review provides a thorough examination of high-performance memristors based on 2D TMCs for neuromorphic computing applications, including the promise of 2D TMC materials and heterostructures, as well as the state-of-the-art demonstration of memristive devices. The challenges and future prospects for the development of these emerging materials and devices are also discussed. The purpose of this review is to provide an outlook on the fabrication and characterization of neuromorphic memristors based on 2D TMCs.
Low-dimensional halide perovskites: review and issues Hong, Kootak; Le, Quyet Van; Kim, Soo Young ...
Journal of materials chemistry. C, Materials for optical and electronic devices,
2018, Letnik:
6, Številka:
9
Journal Article
Recenzirano
Halide perovskites are emerging materials for future optoelectronics and electronics due to their remarkable advantages such as a high light absorption coefficient, long charge carrier diffusion ...length, facile synthesis method, and low cost. As polycrystalline halide perovskite thin films, which have been studied so far, have crucial limitations, low-dimensional halide perovskites have attracted attention due to their unique optical properties and charge transport properties, which have not been observed before. This review highlights the limitations of polycrystalline halide perovskites thin films and the unique characteristics of low-dimensional halide perovskite nanostructures including their electrical, optical, and chemical properties. After introducing the recent developments of various low-dimensional halide perovskite nanostructures including the synthesis methods, their properties, and applications, a brief overview of the challenges of low-dimensional halide perovskites as candidates for future optoelectronics and electronic devices is provided.
Halide perovskites are emerging materials for future optoelectronics and electronics due to their remarkable advantages such as a high light absorption coefficient, long charge carrier diffusion length, facile synthesis method, and low cost.
The multilayered ceramic capacitor (MLCC) is a key component of electronic equipment, such as smartphones, portable PCs and electric vehicles, which contain a number of MLCCs. As MLCCs distribute and ...control the amount of current flowing through circuits, remove noise, and prevent malfunction, MLCCs play a key role in enabling electronic devices to have high performance, multi-functionality, and high integration. This review highlights the critical issues and recent progress in developing highly volumetric-efficient and high capacitance MLCCs from the viewpoint of designing a BaTiO
3
-based dielectric layer. After a brief introduction of MLCCs and dielectric materials, we summarize the current issues in developing BaTiO
3
-based dielectric materials for MLCCs with high performance and reliability and describe the strategies to optimize dielectric properties through nano/microstructure control, chemical modification and doping. Finally, we provide an outlook on the development and future application of MLCCs. It is anticipated that this review can serve as an overview and evaluation of state-of-the-art synthesis and design of BaTiO
3
-based dielectric materials for MLCC applications.
This review highlights the critical issues and recent advances in developing highly volumetric-efficient and high capacitance MLCCs from the viewpoint of designing dielectric materials.
CsPbX3 (X = halide, Cl, Br, or I) all‐inorganic halide perovskites (IHPs) are regarded as promising functional materials because of their tunable optoelectronic characteristics and superior stability ...to organic–inorganic hybrid halide perovskites. Herein, nonvolatile resistive switching (RS) memory devices based on all‐inorganic CsPbI3 perovskite are reported. An air‐stable CsPbI3 perovskite film with a thickness of only 200 nm is successfully synthesized on a platinum‐coated silicon substrate using low temperature all‐solution process. The RS memory devices of Ag/polymethylmethacrylate (PMMA)/CsPbI3/Pt/Ti/SiO2/Si structure exhibit reproducible and reliable bipolar switching characteristics with an ultralow operating voltage (<+0.2 V), high on/off ratio (>106), reversible RS by pulse voltage operation (pulse duration < 1 ms), and multilevel data storage. The mechanical flexibility of the CsPbI3 perovskite RS memory device on a flexible substrate is also successfully confirmed. With analyzing the influence of phase transition in CsPbI3 on RS characteristics, a mechanism involving conducting filaments formed by metal cation migration is proposed to explain the RS behavior of the memory device. This study will contribute to the understanding of the intrinsic characteristics of IHPs for low‐voltage resistive switching and demonstrate the huge potential of them for use in low‐power consumption nonvolatile memory devices on next‐generation computing systems.
Cesium lead iodide (CsPbI3) perovskite, which is all‐inorganic halide perovskite, is synthesized on platinum‐coated silicon substrate for ultralow operating voltage resistive switching memory device. With analyzing the influence of phase transition in CsPbI3 on resistive switching characteristics, an electrochemical metallization mechanism involving metal conducting filaments is proposed to explain the resistive switching behavior for data storage.
Recently, organometallic and all-inorganic halide perovskites (HPs) have become promising materials for resistive switching (RS) nonvolatile memory devices with low power consumption because they ...show current–voltage hysteresis caused by fast ion migration. However, the toxicity and environmental pollution potential of lead, a common constituent of HPs, has limited the commercial applications of HP-based devices. Here, RS memory devices based on lead-free all-inorganic cesium tin iodide (CsSnI3) perovskites with temperature tolerance are successfully fabricated. The devices exhibit reproducible and reliable bipolar RS characteristics in both Ag and Au top electrodes (TEs) with different switching mechanisms. The Ag TE devices show filamentary RS behavior with ultralow operating voltages (<0.15 V). In contrast, the Au TE devices have interface-type RS behavior with gradual resistance changes. This suggests that the RS characteristics are attributed to either the formation of metal filaments or the ion migration of defects in HPs under applied electric fields. These distinct mechanisms may permit the opportunity to design devices for specific purposes. This work will pave the way for lead-free all-inorganic HP-based nonvolatile memory for commercial application in HP-based devices.
Palladium (Pd) has been the key element for several C–C bond-forming reactions, especially the Nobel-acclaimed Suzuki, Heck, and Sonogashira cross-coupling reactions, among others. This review ...article describes recent efforts toward the synthetic strategies, characterization, and development of various nanostructured material supports for adorning Pd nanoparticles and their sustainable use in catalyzing at least one of the three aforementioned transformations. Recent advances are highlighted for assorted nanostructured materials-supported Pd nanocatalysts; designed nanostructures possessing engineered morphologies, magnetic Pd nanocomposites, polymers, metal–organic frameworks, and hybrid nanostructured catalysts are described for diverse Pd nanocatalysts. Selected examples expounding the concepts and rationale behind the reactivity enhancement and the reusability of the nanostructured Pd catalysts are presented via control of the structure, composition, and intrinsic nature of the introduced supports. Heterogeneous cross–coupling catalysis, a necessary tool in everyday chemical transformations, is illustrated, implicating eminent functions presented by the structural properties of the supports, associated pros and cons, their recyclability, and the efficiency.
Direct consideration for both, the catalytically active species and the host materials provides highly efficient strategies for the architecture design of nanostructured catalysts. The conventional ...wet chemical methods have limitations in achieving such unique layer-by-layer design possessing one body framework with many catalyst parts. Herein, an innovative physical method is presented that allows the well-regulated architecture design for an array of functional nanocatalysts as exemplified by layer-by-layer adornment of Pd nanoparticles (NPs) on the highly arrayed silica nanorods. This spatially confined catalyst exhibits excellent efficiency for the hydrogenation of nitroarenes and widely deployed Suzuki cross-coupling reactions; their facile separation from the reaction mixtures is easily accomplished due to the monolithic structure. The generality of this method for the introduction of other metal source has also been demonstrated with Au NPs. This pioneering effort highlights the feasibility of physically controlled architecture design of nanostructured catalysts which may stimulate further studies in the general domain of the heterogeneous catalytic transformations.
Atomically thin two-dimensional materials such as MoS2, WS2, and graphene oxide (GO) are used as hole extraction layers (HEL) in organolead halide perovskites solar cells (PSCs) instead of ...poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) HEL. MoS2 and WS2 layers with a polycrystalline structure were synthesized by a chemical deposition method using a uniformly spin-coated (NH4)MoS4 and (NH4)WS4 precursor solution. GO was synthesized by the oxidation of natural graphite powder using Hummers' method. The work functions of MoS2, WS2, and GO are measured to be 5.0, 4.95, and 5.1 eV, respectively. The X-ray diffraction spectrum indicated that the synthesized perovskite material is CH3NH3PbI3−xClx. The PSCs with the p-n junction structure were fabricated based on the CH3NH3PbI3−xClx perovskite layer. The power conversion efficiencies of the MoS2, WS2, and GO-based PSCs were 9.53%, 8.02%, and 9.62%, respectively, which are comparable to those obtained from PEDOT:PSS-based devices (9.93%). These results suggest that two-dimensional materials such as MoS2, WS2, and GO can be promising candidates for the formation of HELs in the PSCs.
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•MoS2 and WS2 layers were prepared by chemical vapor deposition method.•Graphene oxide (GO) was synthesized by Hummers' method.•MoS2, WS2, and GO can be applied to the hole extraction layer for perovskite solar cell.
We demonstrate that wafer-scale, transferable, and transparent thin-film catalysts based on MoS sub(2), which consists of cheap and earth abundant elements, can provide a low onset potential of 1 mA ...cm super(-2) at 0.17 V versusa reversible hydrogen electrode and the high photocurrent density of 24.6 mA cm super(-2) at 0 V for a p-type Si photocathode. c-Domains with vertically stacked (100) planes in the transferable 2H-MoS sub(2) thin films, which are grown viaa thermolysis method, act as active sites for the hydrogen evolution reaction, and photogenerated electrons are efficiently transported through the n-MoS sub(2)/p-Si heterojunction.
We synthesized the reproducible heterogeneous catalyst of graphene oxide (GO)-supported palladium nanoparticles (NPs) via a simple and green process. The structure, morphology and physicochemical ...properties of the synthesized heterogeneous catalyst were characterized by the latest techniques such as high-resolution transmission electron microscopy (TEM), scanning TEM, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. The GO-supported Pd NPs (Pd/GO nanocatalyst) exhibited excellent catalytic activity for the reduction of nitroaromatics to aminoaromatics in aqueous sodium borohydride. The nitroaromatics were converted to corresponding aminoaromatics with high yields (up to 99%) using Pd/GO nanocatalyst in aqueous solution. The hybrid heterogeneous catalyst showed 83% of conversion after six cycles in the reduction of nitrobenzene to aminobenzene. These features ensured the high catalytic activity of the introduced graphene oxide supported Pd nanocatalysts.
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