Surface contamination by polymer residues has long been a critical problem in probing graphene’s intrinsic properties and using graphene for unique applications surface chemistry, biotechnology, ultrahigh speed electronics. Poly(methyl methacrylate) (PMMA) is macromolecule commonly used transfer device processing, leaving thin layer of residue to be empirically cleaned annealing. Here we report on systematic study PMMA decomposition its impact transmission electron microscopy (TEM)...

Here we show that gas-phase doping by means of NH3 plasma exposure is a highly flexible and manufacturable process for graphene electronics. The nitrogen-containing radicals can readily form covalent bonds with the carbon lattice keep stable in postannealing damage restoration. amount charge transfer be fine tuned controlling time monitored systematic shift Raman G mode Gds−Vg curves transport measurements. maximum level reach 1.5×1013 cm−2.

Rhenium disulfide (ReS2) and diselenide (ReSe2), the group 7 transition metal dichalcogenides (TMDs), are known to have a layered atomic structure showing an in-plane motif of diamond-shaped-chains (DS-chains) arranged in parallel. Using combination transmission electron microscopy transport measurements, we demonstrate here direct correlation anisotropy single-layered ReS2 with orientation DS-chains, as also supported by our density functional theory calculations. We further show that...

Fabrication of large-area clean graphene sheets is the first step toward development high-performance applications in surface chemistry and biotechnology as well high-mobility electronics. Here we demonstrate transfer grown by chemical vapor deposition on Cu foil, with cleanness defined transmission electron microscopy (TEM) combination Raman scattering same position suspended sheets. For graphene, spectra exhibit distinctive features that can explicitly discriminate from covered a thin...

High density and controllable nitrogen doping in graphene is a critical issue to realize high performance graphene-based devices. In this paper, we demonstrate an efficient method selectively produce graphitic-N pyridinic-N defects by using the mixture plasma of ozone nitrogen. The atomic structure, electronic dynamic behavior these are systematically studied at level scanning transmission electron microscopy. exhibits higher chemical activity tends trap series transition metal atoms (Mg,...

In search of high-performance field-effect transistors (FETs) made atomic thin semiconductors, indium selenide (InSe) has held great promise because its high intrinsic mobility and moderate electronic band gap (1.26 eV). Yet the performance InSe FETs is decisively determined by surface oxidation taking place spontaneously in ambient conditions, setting up a ceiling causing an uncontrollable current hysteresis. Encapsulation hexagonal boron nitride (h-BN) been currently used to cope with this...

Abstract As defects frequently govern the properties of crystalline solids, precise microscopic knowledge defect atomic structure is fundamental importance. We report a new class point in single-layer transition metal dichalcogenides that can be created through 60° rotations metal–chalcogen bonds trigonal prismatic lattice, with simplest among them being three-fold symmetric trefoil-like defect. The defects, which are inherently related to crystal symmetry dichalcogenides, expand sequential...

We present a promising technology for nonvolatile flexible electronic devices: A direct fabrication of epitaxial lead zirconium titanate (PZT) on mica substrate via van der Waals epitaxy. These single-crystalline ferroelectric PZT films not only retain their performance, reliability, and thermal stability comparable to those rigid counterparts in tests memory elements but also exhibit remarkable mechanical properties with robust operation bent states (bending radii down 2.5 mm) cycling (1000...

Abstract Alkali metal (AM) intercalation between graphene layers holds promise for electronic manipulation and energy storage, yet the underlying mechanism remains challenging to fully comprehend despite extensive research. In this study, we employ low-voltage scanning transmission electron microscopy (LV-STEM) visualize atomic structure of intercalated AMs (potassium, rubidium, cesium) in bilayer (BLG). Our findings reveal that adopt structures with hcp stacking, specifically a C 6 M 2...

Bilayer graphene is an intriguing material in that its electronic structure can be altered by changing the stacking order or relative twist angle, yielding a new class of low-dimensional carbon system. Twisted bilayer obtained (i) thermal decomposition SiC; (ii) chemical vapor deposition (CVD) on metal catalysts; (iii) folding graphene; (iv) layers one atop other, latter which suffers from interlayer contamination. Existing synthesis protocols, however, usually result with polycrystalline...

Intermolecular carbon nanotube junctions were formed by coupling chemically functionalized nanotubes with molecular linkers. An end-to-side or end-to-end heterojunction can be reacting chloride terminated aliphatic diamine. The modified mats characterized Raman spectroscopy. peak shift in the tangential vibration mode reveals that attached chemical functional groups behave as either an electron donor acceptor, and facilitate charge transfer host. is also verified transport measurements on...

A high-mobility low-voltage graphene field-effect transistor (FET) array was fabricated on a flexible plastic substrate using high-capacitance natural aluminum oxide as gate dielectric in self-aligned device configuration. The high capacitance of the native and self-alignment, which minimizes access resistance, yield current on/off ratio an operation voltage below 3 V, along with electron hole mobility 230 300 cm2/V·s, respectively. Moreover, is resistant to mechanical bending exhibits...

Abstract Conventional methods to prepare large‐area graphene for transparent conducting electrodes involve the wet etching of metal catalyst and transfer film, which can degrade film through creation wrinkles, cracks, or tears. The resulting films may also be obscured by residual impurities polymer contaminants. Here, it is shown that direct growth flat nanographene on silica achieved at low temperature (400 °C) chemical vapor deposition without use catalysts. Raman spectroscopy TEM confirm...

Direct deposition of high-quality graphene layers on insulating substrates such as SiO(2) paves the way toward development graphene-based high-speed electronics. Here, we describe a novel growth technique that enables direct with crystalline quality potentially comparable to grown Cu foils using chemical vapor (CVD). Rather than substrates, our approach uses them provide subliming atoms in CVD process. The prime feature proposed is remote catalyzation floating and H for decomposition...

Domain walls in multiferroics can exhibit intriguing behaviors that are significantly different from the bulk of material. We investigate strong magnetoresistance domain model multiferroic BiFeO3 by probing ordered arrays 109° with temperature- and magnetic-field-dependent transport. observe temperature-dependent variations transport mechanism magnetoresistances as large 60%. These results suggest locally breaking symmetry a material, such at structural interfaces, one induce emergent...

Vanadium dioxide (VO2) is a compelling candidate for next-generation electronics beyond conventional silicon-based devices due to the exhibition of sharp metal–insulator transition. In this study, in order realize functional VO2 film flexible electronics, growth directly on transparent and muscovite via van der Waals epitaxy established. The heteroepitaxy structural transition films are examined by combination high-resolution X-ray diffraction, transmission electron microscopy, Raman...

Abstract The understanding of interactions between electrons and phonons in atomically thin heterostructures is crucial for the engineering novel two-dimensional devices. Electron–phonon (el–ph) layered materials can occur involving same layer or different layers. Here we report on possibility distinguishing intralayer interlayer el–ph samples twisted bilayer graphene probing process graphene/h-BN by using Raman spectroscopy. In process, scattering occurs a single other (graphene h-BN)...

Performance of 2D photodetectors is often predominated by charge traps that offer an effective photogating effect. The device features ultrahigh gain and responsivity, but at the cost a retarded temporal response due to nature long-lived trap states. In this work, we devise mechanism originates from massive puddles formed in type-II lateral heterostructures. This concept demonstrated using graphene-contacted WS2 embedded with WSe2 nanodots. Upon light illumination, photoexcited carriers are...

Spintronics has captured a lot of attention since it was proposed. It been triggering numerous research groups to make their efforts on pursuing spin-related electronic devices. Recently, flexible and wearable devices are in high demand due outstanding potential practical applications. In order introduce spintronics into the realm devices, we demonstrate that is feasible grow epitaxial Fe3O4 film, promising candidate for realizing spintronic based tunneling magnetoresistance, muscovite. this...

Abstract Most chemical vapor deposition methods for transition metal dichalcogenides use an extremely small amount of precursor to render large single-crystal flakes, which usually causes low coverage the materials on substrate. In this study, a self-capping vapor-liquid-solid reaction is proposed fabricate large-grain, continuous MoS 2 films. An intermediate liquid phase-Na Mo O 7 formed through eutectic MoO 3 and NaF, followed by being sulfurized into . The as-formed seeds function as...

Flexible electronics have a great potential to impact consumer and with that our daily life. Currently, no direct growth of epitaxial functional oxides on commercially available flexible substrates is possible. In this study, in order address challenge, muscovite, common layered oxide, used as substrate chemically similar typical oxides. We fabricated MoO2 films muscovite via pulsed laser deposition technique. A combination X-ray diffraction transmission electron microscopy confirms van der...

To control the spin state of an individual atom is ultimate goal for spintronics. A single magnet, which may lead to a supercapacity memory device if realized, requires high-spin isolated atom. Here, we demonstrate realization well transition metal (TM) atoms fixed at atomic defects sparsely dispersed in graphene. Core-level electron spectroscopy clearly reveals TM divacancy or edge graphene layer. We also show first time that systematically varies with coordination neighboring nitrogen...

The emerging technological demands for flexible and transparent electronic devices have compelled researchers to look beyond the current silicon-based electronics. However, fabrication of on conventional substrates with superior performance are constrained by trade-off between processing temperature device performance. Here, we propose an alternative strategy circumvent this issue via heteroepitaxial growth conducting oxides (TCO) mica substrate comparable that their rigid counterparts. With...