Enhanced catalytic activity on atomically dispersed PtSe two-dimensional layers.

A key challenge in heterogeneous catalysis is to design atomically dispersed catalysts with high surface density, while simultaneously preventing agglomeration and promoting electronic metal-support interaction. Transition metal dichalcogenides (TMDs), such as platinum diselenide (PtSe), offer a promising solution due to their unique structural and electronic properties. This study proposes a catalyst design that utilizes atomically dispersed transition metal species within the topmost layer of TMD as catalytic reaction sites.

BEOL-Compatible Tellurium Films for Optically Stimulated and Mechanically Deformable Artificial Synapses.

The prevailing von Neumann bottleneck has demanded alternatives capable of more efficiently executing massive data in state-of-the-art digital technologies. Mimicking the human brain's operational principles, various artificial synapse devices have emerged, whose fabrications generally require high-temperature complementary metal-oxide-semiconductor (CMOS) processes. Herein, centimeter-scale tellurium (Te) films-based optoelectronic synaptic devices are explored by a back-end-of-line (BEOL) compatible low-temperature (200 °C) chemical vapor deposition (CVD).

Rapid Diagnosis of Major Phytoplasma Infected Trees Using the Loop-Mediated Isothermal Amplification Method in South Korea.

Tree diseases associated with phytoplasma infections predominantly affecting nine host trees have serious impacts on tree growth and cause significant economic losses in South Korea. Loop-mediated isothermal amplification (LAMP)-based primers for early detection were developed to evaluate their accuracy. First, the 16S rRNA gene of phytoplasma was successfully amplified from the extracted DNA of various infected tree species using the polymerase chain reaction method.

Wafer-Scale Tellurium Nanotube Meshes for Optically Modulated and Mechanically Flexible Artificial Synapses.

Tellurium (Te) nanotube (NT) meshes fabricated via a scalable low-temperature chemical vapor deposition (CVD) process are being explored for flexible optoelectronic synapse applications. Centimeter-scale meshes composed of highly networked single-crystalline individual Te nanorods are directly grown on polymeric substrates at a low temperature of 350 °C. The Te NT meshes exhibit -type semiconducting behaviors accompanied by an optical bandgap of ∼0.

Erratum: Two-Dimensional Near-Atom-Thickness Materials for Emerging Neuromorphic Devices and Applications.

[This corrects the article DOI: 10.1016/j.isci.

Centimeter-Scale Ultrathin Platinum Monosulfide Films with Large Negative Temperature Coefficient of Resistance for Deformable Visible-to-Mid-Infrared Photodetectors.

Broadband photodetectors covering a spectrum range of visible-to-mid-infrared (Mid-IR) are widely utilized for a range of applications, such as chemical sensing and medical devices. As their physical form factors evolve, a variety of photoresponsive electronic materials have been explored to adapt their demanded mechanical deformability. Herein, we report on a chemical vapor deposition (CVD) growth of centimeter-sized ultrathin (i.

Piezostrain-Driven Bidirectional Enhancement of Optical Synaptic Plasticity in Wafer-Scale Co-Phased Tin Selenide Layers.

Tin (Sn)-based two-dimensional (2D) materials exhibit intriguing mechanical and optoelectrical properties owing to their non-centrosymmetric crystallinity and tunable band structures. A judicious integration of these individually decoupled properties is projected to introduce unparalleled functionalities into them, which remain largely unexplored. Herein, we develop wafer-scale tin selenide (SnSe, 0 < < 1) 2D layers composed of thermodynamically stable coexisting phases of SnSe and SnSe with distinct functionalities and identify a strong interplay between their mechanical and optoelectrical characteristics.

Introducing Semiconducting-to-Metallic Transitions into Wafer-Scale 2D PdSe Layers by Low-Temperature Anion Exchange and Thickness Modulation.

Two-dimensional (2D) palladium diselenide (PdSe) layers are projected to exhibit a number of intriguing electrical properties such as semiconducting-to-metallic transitions. Precisely modulating their morphology and chemistry is essential for realizing such opportunities, which is particularly demanded on a large dimension under flexible processing conditions toward broadening their practical device applicability. Herein, we explore a wafer-scale growth of 2D PdSe layers and introduce semiconducting-to-metallic transitions into them at as low as 330 °C, a temperature compatible with a range of polymeric substrates as well as the back-end-of-line (BEOL) processes.

Wafer-Scale Freestanding Monocrystalline Chalcogenide Membranes by Strain-Assisted Epitaxy and Spalling.

Monocrystalline chalcogenide thin films in freestanding forms are very much needed in advanced electronics such as flexible phase change memories (PCMs). However, they are difficult to manufacture in a scalable manner due to their growth and delamination challenges. Herein, we report a viable strategy for a wafer-scale epitaxial growth of monocrystalline germanium telluride (GeTe) membranes and their deterministic integrations onto flexible substrates.

Calcium Alginate as an Active Device Component for Light-Triggered Degradation of 2D MoS-Based Transient Electronics.

Transient electronics technology has enabled the programmed disintegration of functional devices, paving the way for environmentally sustainable management of electronic wastes as well as facilitating the exploration of novel device concepts. While a variety of inorganic and/or organic materials have been employed as media to introduce transient characteristics in electronic devices, they have been mainly limited to function as passive device components. Herein, we report that calcium (Ca) alginate, a natural biopolymer, exhibits multifunctionalities of introducing light-triggered transient characteristics as well as constituting active components in electronic devices integrated with two-dimensional (2D) molybdenum disulfide (MoS) layers.

Centimeter-Scale Tellurium Oxide Films for Artificial Optoelectronic Synapses with Broadband Responsiveness and Mechanical Flexibility.

Prevailing over the bottleneck of von Neumann computing has been significant attention due to the inevitableness of proceeding through enormous data volumes in current digital technologies. Inspired by the human brain's operational principle, the artificial synapse of neuromorphic computing has been explored as an emerging solution. Especially, the optoelectronic synapse is of growing interest as vision is an essential source of information in which dealing with optical stimuli is vital.

High Mobility Transistors and Flexible Optical Synapses Enabled by Wafer-Scale Chemical Transformation of Pt-Based 2D Layers.

Electronic devices employing two-dimensional (2D) van der Waals (vdW) transition-metal dichalcogenide (TMD) layers as semiconducting channels often exhibit limited performance (e.g., low carrier mobility), in part, due to their high contact resistances caused by interfacing non-vdW three-dimensional (3D) metal electrodes.

Reversible Transition of Semiconducting PtSe and Metallic PtTe for Scalable All-2D Edge-Contacted FETs.

Two-dimensional (2D) transition metal dichalcogenide (TMD) layers are highly promising as field-effect transistor (FET) channels in the atomic-scale limit. However, accomplishing this superiority in scaled-up FETs remains challenging due to their van der Waals (vdW) bonding nature with respect to conventional metal electrodes. Herein, we report a scalable approach to fabricate centimeter-scale all-2D FET arrays of platinum diselenide (PtSe) with in-plane platinum ditelluride (PtTe) edge contacts, mitigating the aforementioned challenges.

Molecular Detection of Phytoplasmas of the 16SrⅠ and 16SrXXXⅡ Groups in Elaeocarpus sylvestris Trees with Decline Disease in Jeju Island, South Korea.

Phytoplasmas were discovered in diseased Elaeocarpus sylvestris trees growing on Jeju Island that showed symptoms of yellowing and darkening in the leaves. Leaf samples from 14 symptomatic plants in Jeju-si and Seogwipo-si were collected and phytoplasma 16S rRNA was successfully amplified by nested polymerase chain reaction using universal primers. The sequence analysis detected two phytoplasmas, which showed 99.

Large-area vertically aligned 2D MoSlayers on TEMPO-cellulose nanofibers for biodegradable transient gas sensors.

Crystallographically anisotropic two-dimensional (2D) molybdenum disulfide (MoS) with vertically aligned (VA) layers is attractive for electrochemical sensing owing to its surface-enriched dangling bonds coupled with extremely large mechanical deformability. In this study, we explored VA-2D MoSlayers integrated on cellulose nanofibers (CNFs) for detecting various volatile organic compound gases. Sensor devices employing VA-2D MoS/CNFs exhibited excellent sensitivities for the tested gases of ethanol, methanol, ammonia, and acetone; e.

Multiwavelength Optoelectronic Synapse with 2D Materials for Mixed-Color Pattern Recognition.

Neuromorphic visual systems emulating biological retina functionalities have enormous potential for in-sensor computing, with prospects of making artificial intelligence ubiquitous. Conventionally, visual information is captured by an image sensor, stored by memory units, and eventually processed by the machine learning algorithm. Here, we present an optoelectronic synapse device with multifunctional integration of all the processes required for real time object identification.

Peel-and-Stick Integration of Atomically Thin Nonlayered PtS Semiconductors for Multidimensionally Stretchable Electronic Devices.

Various near-atom-thickness two-dimensional (2D) van der Waals (vdW) crystals with unparalleled electromechanical properties have been explored for transformative devices. Currently, the availability of 2D vdW crystals is rather limited in nature as they are only obtained from certain mother crystals with intrinsically possessed layered crystallinity and anisotropic molecular bonding. Recent efforts to transform conventionally non-vdW three-dimensional (3D) crystals into ultrathin 2D-like structures have seen rapid developments to explore device building blocks of unique form factors.

MoS Synapses with Ultra-low Variability and Their Implementation in Boolean Logic.

Brain-inspired computing enabled by memristors has gained prominence over the years due to the nanoscale footprint and reduced complexity for implementing synapses and neurons. The demonstration of complex neuromorphic circuits using conventional materials systems has been limited by high cycle-to-cycle and device-to-device variability. Two-dimensional (2D) materials have been used to realize transparent, flexible, ultra-thin memristive synapses for neuromorphic computing, but with limited knowledge on the statistical variation of devices.

Mechanically rollable photodetectors enabled by centimetre-scale 2D MoS layer/TOCN composites.

Two-dimensional (2D) molybdenum disulfide (MoS) layers are suitable for visible-to-near infrared photodetection owing to their tunable optical bandgaps. Also, their superior mechanical deformability enabled by an extremely small thickness and van der Waals (vdW) assembly allows them to be structured into unconventional physical forms, unattainable with any other materials. Herein, we demonstrate a new type of 2D MoS layer-based rollable photodetector that can be mechanically reconfigured while maintaining excellent geometry-invariant photo-responsiveness.

Vertically Aligned 2D MoS Layers with Strain-Engineered Serpentine Patterns for High-Performance Stretchable Gas Sensors: Experimental and Theoretical Demonstration.

Two-dimensional (2D) molybdenum disulfide (MoS) with vertically aligned (VA) layers exhibits significantly enriched surface-exposed edge sites with an abundance of dangling bonds owing to its intrinsic crystallographic anisotropy. Such structural variation renders the material with exceptionally high chemical reactivity and chemisorption ability, making it particularly attractive for high-performance electrochemical sensing. This superior property can be further promoted as far as it is integrated on mechanically stretchable substrates well retaining its surface-exposed defective edges, projecting opportunities for a wide range of applications utilizing its structural uniqueness and mechanical flexibility.

Two-Dimensional Near-Atom-Thickness Materials for Emerging Neuromorphic Devices and Applications.

Two-dimensional (2D) layered materials and their heterostructures have recently been recognized as promising building blocks for futuristic brain-like neuromorphic computing devices. They exhibit unique properties such as near-atomic thickness, dangling-bond-free surfaces, high mechanical robustness, and electrical/optical tunability. Such attributes unattainable with traditional electronic materials are particularly promising for high-performance artificial neurons and synapses, enabling energy-efficient operation, high integration density, and excellent scalability.

Wafer-Scale Two-Dimensional MoS Layers Integrated on Cellulose Substrates Toward Environmentally Friendly Transient Electronic Devices.

We explored the feasibility of wafer-scale two-dimensional (2D) molybdenum disulfide (MoS) layers toward futuristic environmentally friendly electronics that adopt biodegradable substrates. Large-area (> a few cm) 2D MoS layers grown on silicon dioxide/silicon (SiO/Si) wafers were delaminated and integrated onto a variety of cellulose-based substrates of various components and shapes in a controlled manner; examples of the substrates include planar papers, cylindrical natural rubbers, and 2,2,6,6-tetramethylpiperidine-1-oxyl-oxidized cellulose nanofibers. The integrated 2D layers were confirmed to well preserve their intrinsic structural and chemical integrity even on such exotic substrates.

Wafer-scale 2D PtTe layers for high-efficiency mechanically flexible electro-thermal smart window applications.

Two-dimensional (2D) transition metal dichalcogenide (TMD) layers have gained increasing attention for a variety of emerging electrical, thermal, and optical applications. Recently developed metallic 2D TMD layers have been projected to exhibit unique attributes unattainable in their semiconducting counterparts; e.g.

Automated Assembly of Wafer-Scale 2D TMD Heterostructures of Arbitrary Layer Orientation and Stacking Sequence Using Water Dissoluble Salt Substrates.

We report a novel strategy to assemble wafer-scale two-dimensional (2D) transition metal dichalcogenide (TMD) layers of well-defined components and orientations. We directly grew a variety of 2D TMD layers on "water-dissoluble" single-crystalline salt wafers and precisely delaminated them inside water in a chemically benign manner. This manufacturing strategy enables the automated integration of vertically aligned 2D TMD layers as well as 2D/2D heterolayers of arbitrary stacking orders on exotic substrates insensitive to their kind and shape.