Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Direct Synthesis of Large-Scale Multilayer TaSe2 on SiO2/Si Using Ion Beam Technology.

ABSTRACT: The multilayer 1T-TaSe2 is successfully synthesized by annealing a Se-implanted Ta thin film on the SiO2/Si substrate. Material analyses confirm the 1T (octahedral) structure and the quasi-2D nature of the prepared TaSe2. Temperature-dependent resistivity reveals that the multilayer 1T-TaSe2 obtained by our method undergoes a commensurate charge-density wave (CCDW) transition at around 500 K. This synthesis process has been applied to synthesize MoSe2 and HfSe2 and expanded for synthesis of one more transition-metal dichalcogenide (TMD) material. In addition, the main issue of the process, that is, the excess metal capping on the TMD layers, is solved by the reduction of thickness of the as-deposited metal thin film in this work.

SUBMITTER: Tsai HS

PROVIDER: S-EPMC6812130 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Direct Synthesis of Large-Scale Multilayer TaSe2 on SiO2/Si Using Ion Beam Technology.

Tsai Hsu-Sheng HS Liu Fan-Wei FW Liou Jhe-Wei JW Chi Chong-Chi CC Tang Shin-Yi SY Wang Changan C Ouyang Hao H Chueh Yu-Lun YL Liu Chaoming C Zhou Shengqiang S Woon Wei-Yen WY

ACS omega 20191008 17

The multilayer 1T-TaSe2 is successfully synthesized by annealing a Se-implanted Ta thin film on the SiO2/Si substrate. Material analyses confirm the 1T (octahedral) structure and the quasi-2D nature of the prepared TaSe2. Temperature-dependent resistivity reveals that the multilayer 1T-TaSe2 obtained by our method undergoes a commensurate charge-density wave (CCDW) transition at around 500 K. This synthesis process has been applied to synthesize MoSe<s ...[more]

PMID: 31656926

Similar Datasets

Synthesis and photoluminescence properties of silica-modified SiO2@ANA-Si-Tb@SiO2, SiO2@ANA-Si-Tb-L@SiO2 core-shell-shell nanostructured composites.

Project description:Three novel core-shell nanostructured composites SiO2@ANA-Si-Tb, SiO2@ANA-Si-Tb-L (L = second ligand) with SiO2 as the core and terbium organic complex as the shell were successfully synthesized. The core and shell were connected together by covalent bonds. The terbium ion was coordinated with organic ligand-forming terbium organic complex in the shell layer. The organosilane (HOOCC5H4NN(CONH(CH2)3Si(OCH2CH3)3)2 (abbreviated as ANA-Si) was used as the first ligand and 1,10-phenanthroline (phen) or 2-thenoyltrifluoroacetone (TTA) was used as the second ligand. Furthermore, silica-modified SiO2@ANA-Si-Tb@SiO2, SiO2@ANA-Si-Tb-L@SiO2 core-shell-shell nanostructured composites were also synthesized by sol-gel chemical route, which involved the hydrolysis and polycondensation processes of tetraethoxysilane (TEOS) using cetyltrimethyl ammonium bromide (CTAB) as a surface-active agent. An amorphous silica shell was coated around the SiO2@ANA-Si-Tb, SiO2@ANA-Si-Tb-L core-shell nanostructured composites. The core-shell and core-shell-shell nanostructured composites exhibited excellent luminescence in the solid state. Meanwhile, an improved luminescent stability property of the core-shell-shell nanostructured composites was observed for the aqueous solution. This type of core-shell-shell nanostructured composites exhibited bright luminescence, high stability and good solubility, which may present potential applications in the fields of optoelectronic devices, bio-imaging, medical diagnosis and study on the structure of function composite materials.

| S-EPMC6731695 | biostudies-literature

Ion-Beam-Induced Atomic Mixing in Ge, Si, and SiGe, Studied by Means of Isotope Multilayer Structures.

Project description:Crystalline and preamorphized isotope multilayers are utilized to investigate the dependence of ion beam mixing in silicon (Si), germanium (Ge), and silicon germanium (SiGe) on the atomic structure of the sample, temperature, ion flux, and electrical doping by the implanted ions. The magnitude of mixing is determined by secondary ion mass spectrometry. Rutherford backscattering spectrometry in channeling geometry, Raman spectroscopy, and transmission electron microscopy provide information about the structural state after ion irradiation. Different temperature regimes with characteristic mixing properties are identified. A disparity in atomic mixing of Si and Ge becomes evident while SiGe shows an intermediate behavior. Overall, atomic mixing increases with temperature, and it is stronger in the amorphous than in the crystalline state. Ion-beam-induced mixing in Ge shows no dependence on doping by the implanted ions. In contrast, a doping effect is found in Si at higher temperature. Molecular dynamics simulations clearly show that ion beam mixing in Ge is mainly determined by the thermal spike mechanism. In the case of Si thermal spike, mixing prevails at low temperature whereas ion beam-induced enhanced self-diffusion dominates the atomic mixing at high temperature. The latter process is attributed to highly mobile Si di-interstitials formed under irradiation and during damage annealing.

| S-EPMC5551856 | biostudies-other

Synthesis of Pt nanoparticles and their burrowing into Si due to synergistic effects of ion beam energy losses.

Project description:We report the synthesis of Pt nanoparticles and their burrowing into silicon upon irradiation of a Pt-Si thin film with medium-energy neon ions at constant fluence (1.0 × 10(17) ions/cm(2)). Several values of medium-energy neon ions were chosen in order to vary the ratio of the electronic energy loss to the nuclear energy loss (S e/S n) from 1 to 10. The irradiated films were characterized using Rutherford backscattering spectroscopy (RBS), atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). A TEM image of a cross section of the film irradiated with S e/S n = 1 shows ?5 nm Pt NPs were buried up to ?240 nm into the silicon. No silicide phase was detected in the XRD pattern of the film irradiated at the highest value of S e/S n. The synergistic effect of the energy losses of the ion beam (molten zones are produced by S e, and sputtering and local defects are produced by S n) leading to the synthesis and burrowing of Pt NPs is evidenced. The Pt NP synthesis mechanism and their burrowing into the silicon is discussed in detail.

| S-EPMC4222290 | biostudies-literature

Three-dimensional crossbar arrays of self-rectifying Si/SiO2/Si memristors.

Project description:Memristors are promising building blocks for the next-generation memory and neuromorphic computing systems. Most memristors use materials that are incompatible with the silicon dominant complementary metal-oxide-semiconductor technology, and require external selectors in order for large memristor arrays to function properly. Here we demonstrate a fully foundry-compatible, all-silicon-based and self-rectifying memristor that negates the need for external selectors in large arrays. With a p-Si/SiO2/n-Si structure, our memristor exhibits repeatable unipolar resistance switching behaviour (105 rectifying ratio, 104 ON/OFF) and excellent retention at 300?°C. We further build three-dimensinal crossbar arrays (up to five layers of 100?nm memristors) using fluid-supported silicon membranes, and experimentally confirm the successful suppression of both intra- and inter-layer sneak path currents through the built-in diodes. The current work opens up opportunities for low-cost mass production of three-dimensional memristor arrays on large silicon and flexible substrates without increasing circuit complexity.

| S-EPMC5465358 | biostudies-literature

Arrays of Si vacancies in 4H-SiC produced by focused Li ion beam implantation.

Project description:Point defects in SiC are an attractive platform for quantum information and sensing applications because they provide relatively long spin coherence times, optical spin initialization, and spin-dependent fluorescence readout in a fabrication-friendly semiconductor. The ability to precisely place these defects at the optimal location in a host material with nano-scale accuracy is desirable for integration of these quantum systems with traditional electronic and photonic structures. Here, we demonstrate the precise spatial patterning of arrays of silicon vacancy ([Formula: see text]) emitters in an epitaxial 4H-SiC (0001) layer through mask-less focused ion beam implantation of Li+. We characterize these arrays with high-resolution scanning confocal fluorescence microscopy on the Si-face, observing sharp emission lines primarily coming from the [Formula: see text] zero-phonon line (ZPL). The implantation dose is varied over 3 orders of magnitude, leading to [Formula: see text] densities from a few per implantation spot to thousands per spot, with a linear dependence between ZPL emission and implantation dose. Optically-detected magnetic resonance (ODMR) is also performed, confirming the presence of V2 [Formula: see text]. Our investigation reveals scalable and reproducible defect generation.

| S-EPMC7878855 | biostudies-literature

Optical fiber tip templating using direct focused ion beam milling.

Project description:We report on a method for integrating sub-wavelength resonant structures on top of optical fiber tip. Our fabrication technique is based on direct milling of the glass on the fiber facet by means of focused ion beam. The patterned fiber tip acts as a structured template for successive depositions of any responsive or functional overlay. The proposed method is validated by depositing on the patterned fiber a high refractive index material layer, to obtain a 'double-layer' photonic crystal slab supporting guided resonances, appearing as peaks in the reflection spectrum. Morphological and optical characterizations are performed to investigate the effects of the fabrication process. Our results show how undesired effects, intrinsic to the fabrication procedure should be taken into account in order to guarantee a successful development of the device. Moreover, to demonstrate the flexibility of our approach and the possibility to engineering the resonances, a thin layer of gold is also deposited on the fiber tip, giving rise to a hybrid photonic-plasmonic structure with a complementary spectral response and different optical field distribution at the resonant wavelengths. Overall, this work represents a significant step forward the consolidation of Lab-on-Fiber Technology.

| S-EPMC4632123 | biostudies-literature

Wafer-scale synthesis of monodisperse synthetic magnetic multilayer nanorods.

Project description:A double exposure technique has been used to fabricate nanoimprint stamps for making monodisperse nanorods with controllable lengths. The nanorod length is defined by a normal photolithography projection process whereas the nanorod width is defined by an edge-lithography process using a soft polydimethylsiloxane (PDMS) contact mask. Taking advantage of edge-lithography, the nanorod width can be less than the diffraction limit of the exposure light. Using these nanorod stamps, synthetic magnetic multilayer (SMM) nanorods have been fabricated using nanoimprint lithography, resulting in a length variation of ?3%. Nanorod magnetic properties have been characterized in both longitudinal and in-plane transverse directions of the nanorods. A theoretical model has been established to explain the magnetic responses and has revealed that both shape anisotropy and interlayer interactions are important in determining the properties of SMM nanorods.

| S-EPMC3931460 | biostudies-literature

Serial sectioning for examination of photoreceptor cell architecture by focused ion beam technology.

Project description:Structurally deciphering complex neural networks requires technology with sufficient resolution to allow visualization of single cells and their intimate surrounding connections. Scanning electron microscopy (SEM), coupled with serial ion ablation (SIA) technology, presents a new avenue to study these networks. SIA allows ion ablation to remove nanometer sections of tissue for SEM imaging, resulting in serial section data collection for three-dimensional reconstruction. Here we highlight a method for preparing retinal tissues for imaging of photoreceptors by SIA-SEM technology. We show that this technique can be used to visualize whole rod photoreceptors and the internal disc elements from wild-type (wt) mice. The distance parameters of the discs and photoreceptors are in good agreement with previous work with other methods. Moreover, we show that large planes of retinal tissue can be imaged at high resolution to display the packing of normal rods. Finally, SIA-SEM imaging of retinal tissue from a mouse model (Nrl?/?) with phenotypic changes akin to the human disease enhanced S-cone syndrome (ESCS) revealed a structural profile of overall photoreceptor ultrastructure and internal elements that accompany this disease. Overall, this work presents a new method to study photoreceptor cells at high structural resolution that has a broad applicability to the visual neuroscience field.

| S-EPMC3090522 | biostudies-literature

Directed Self-Assembly of Ge Quantum Dots Using Focused Si2+ Ion Beam Patterning.

Project description:We show that templating a Si surface with a focused beam of Si2+ or Si+ ions can create suitable nucleation sites for the subsequent growth of self-assembled Ge quantum dots by chemical vapor deposition. To determine the mechanism of patterning we use atomic force microscopy to show that, similar to Ga+ patterning, the formation of a surface pit is required to enable control over Ge quantum dot locations. We find that relatively high implantation doses are required to achieve patterning, and these doses lead to amorphization of the substrate. We assess the degree to which the substrate crystallinity can be recovered by subsequent processing. Using in situ transmission electron microscopy heating experiments we find that recrystallization is possible at the growth temperature of the Ge quantum dots, but defects remain that follow the pattern of the initial implantation. We discuss the formation mechanism of the defects and the benefits of using Si ions for patterning both defects and quantum dots on Si substrates.

| S-EPMC6008470 | biostudies-literature

Dual beam organic depth profiling using large argon cluster ion beams.

Project description:Argon cluster sputtering of an organic multilayer reference material consisting of two organic components, 4,4'-bis[N-(1-naphthyl-1-)-N-phenyl- amino]-biphenyl (NPB) and aluminium tris-(8-hydroxyquinolate) (Alq3), materials commonly used in organic light-emitting diodes industry, was carried out using time-of-flight SIMS in dual beam mode. The sample used in this study consists of a ?400-nm-thick NPB matrix with 3-nm marker layers of Alq3 at depth of ?50, 100, 200 and 300 nm. Argon cluster sputtering provides a constant sputter yield throughout the depth profiles, and the sputter yield volumes and depth resolution are presented for Ar-cluster sizes of 630, 820, 1000, 1250 and 1660 atoms at a kinetic energy of 2.5 keV. The effect of cluster size in this material and over this range is shown to be negligible. © 2014 The Authors. Surface and Interface Analysis published by John Wiley & Sons Ltd.

| S-EPMC4376248 | biostudies-literature