A5022669660- Advanced Electron Microscopy Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Near-Field Optical Microscopy
- Orbital Angular Momentum in Optics
- Random lasers and scattering media
- Chalcogenide Semiconductor Thin Films
- Phase-change materials and chalcogenides
- Digital Holography and Microscopy
- Advanced X-ray Imaging Techniques
- Quantum Dots Synthesis And Properties
- Advanced Fluorescence Microscopy Techniques
- Electrohydrodynamics and Fluid Dynamics
- Gold and Silver Nanoparticles Synthesis and Applications
- MXene and MAX Phase Materials
- Optical Polarization and Ellipsometry
- Force Microscopy Techniques and Applications
- 2D Materials and Applications
- Magnetic properties of thin films
- Engineering Applied Research
- Photosynthetic Processes and Mechanisms
- Advanced Optical Imaging Technologies
- Engineering Structural Analysis Methods
- Perovskite Materials and Applications
- Spectroscopy Techniques in Biomedical and Chemical Research
- Nanowire Synthesis and Applications
Istituto Nanoscienze
2018-2025
National Research Council
2018-2021
United States Nuclear Regulatory Commission
2021
Institute of Materials for Electronics and Magnetism
2010-2019
Leibniz Institute for Crystal Growth
2019
Institute for Scientific Interchange
2014-2016
University of Oregon
2015
Although water is considered detrimental for Li-ion battery technology, a 1% w/w amount of in melt LiCl ionic liquid 1-butyl-3-methylimidazolium chloride promotes the reduction lithium into LiAl intermetallic along with oxidation to O2 gas. The electrodeposition an layer several micrometers thickness demonstrated by combining complementary techniques, such as galvanostatics, X-ray diffraction, electron energy-loss spectroscopy, mass spectrometry, and 1H nuclear magnetic resonance....
The structural defects in two-dimensional transition metal dichalcogenides, including point defects, dislocations and grain boundaries, are scarcely considered regarding their potential to manipulate the electrical optical properties of this class materials, notwithstanding significant advances already made. Indeed, impurities vacancies may influence exciton population, create disorder-induced localization, as well modify behaviour material. Here we report on experimental evidence, confirmed...
We report the first experimental demonstration of an electrostatic electron orbital angular momentum (OAM) sorter, which can be used to analyze OAM states electrons in a transmission microscope. verify sorter functionality for several beams possessing different superpositions states, and use it record spectra. Our current has resolution 2 units h/bar - reduced Planck constant. It is expected increase optimal 1 future via fine control sorting phase elements.
Spatiotemporal electron-beam shaping is a bold frontier of electron microscopy. Over the past decade, methods evolved from static phase plates to low-speed electrostatic and magnetostatic displays. Recently, swift change paradigm utilizing light control free electrons has emerged. Here, we experimentally demonstrate arbitrary transverse modulation beams without complicated electron-optics elements or material nanostructures, but rather using shaped beams. On-demand spatial wavepackets...
Combining aberration corrected high resolution transmission electron microscopy and density functional theory calculations we propose an explanation of the antisurfactant effect Si in GaN growth. We identify atomic structure a delta-doped layer (commonly called ${\mathrm{SiN}}_{x}$ mask) as ${\mathrm{SiGaN}}_{3}$ monolayer that resembles $\sqrt{3}\ifmmode\times\else\texttimes\fi{}\sqrt{3}\text{ }R30\ifmmode^\circ\else\textdegree\fi{}$ surface reconstruction containing one atom, Ga vacancy...
Silicon, the mainstay semiconductor in microelectronic circuitry, is considered unsuitable for optoelectronic applications owing to its indirect electronic band gap, which limits efficiency as a light emitter. Here we show emission properties of boron-doped wurtzite silicon nanowires measured by cathodoluminescence spectroscopy at room temperature. A visible emission, peaked above 1.5 eV and near infra-red 0.8 correlate respectively direct transition Γ point band-gap silicon. We find...
One of the main limitations to application gold nanorods (Au NRs) as surface-enhanced Raman scattering (SERS) probes for in situ monitoring chemical processes is their instability oxidative environments. Oxidation induces progressive anisotropic shortening NRs, which are eventually dissolved once this process has been completed. This paper compares two types Au obtained through different routes and characterized by similar aspect ratios but sizes. The key factors influencing resistance NRs...
The development of highly active, cheap, and stable electrocatalysts for overall water splitting is strategic industrial electrolysis processes aiming to achieve sustainable hydrogen production. Here, we report the impressive electrocatalytic activity oxygen evolution reaction Al-doped Ni(OH)2 deposited on a chemically etched carbon nanotube forest (CNT-F) supported flexible polymer/CNT nanocomposite. Our monolithic electrode generates current density 10 mA/cm2 at an overpotential (η) 0.28 V...
Chemical vapor deposition has been demonstrated to be the most efficient, versatile and reliable technique for synthesis of monolayers transition metal dichalcogenides. The use organic promoters during growth process was a turning point in order increase monolayer lateral size or obtain complete coverage substrate. In this work we clarify influence promoter gradient on dynamics MoS2. particular, place sacrificial substrate covered with (a low sublimation-temperature perylene-based compound)...
The use of metal nanoparticles is an established paradigm for the synthesis semiconducting one-dimensional nanostructures. In this work we study their effect on two-dimensional materials, by using gold chemical vapor deposition growth molybdenum disulfide (MoS
Single-pixel imaging, originally developed in light optics, facilitates fast three-dimensional sample reconstruction as well probing with wavelengths undetectable by conventional multi-pixel detectors. However, the spatial resolution of optics-based single-pixel microscopy is limited diffraction to hundreds nanometers. Here, we propose an implementation imaging relying on attainable modifications currently available ultrafast electron microscopes which optically modulated electrons are used...
The self-assembly of Ge1Sb2Te4 nanowires (NWs) for phase change memories application was achieved by metal organic chemical vapor deposition, catalyzed Au nanoislands in a narrow range temperatures and deposition pressures. In the optimized conditions 400 °C, 50 mbar, NWs are single hexagonal crystals. Phase memory switching reversibly induced nanosecond current pulses through metal-contacted with threshold voltage about 1.35 V.
It is demonstrated that boron-doped nanowires have predominantly long-term stable wurtzite phase while the majority of phosphorus-doped ones present diamond phase. A simplified model based on different solubility boron and phosphorus in gold proposed to explain their diverse effectiveness retaining The a direct transition at Γ point approximately 1.5 eV predominant emission around 1.1 eV. aforementioned results are intriguing for innovative solar cell devices.
We report the use of an electrostatic micro-electromechanical systems-based device to produce high quality electron vortex beams with more than 1000 quanta orbital angular momentum (OAM). Diffraction and off-axis holography experiments are used show that diameter in diffraction plane increases linearly OAM, thereby allowing content be calibrated. The realization even larger values OAM is currently limited by breakdown voltage device. Potential solutions overcome this problem discussed.
The experimentally retrieved value of the optical extinction cross section per unit length, σL,extNT, individual MoS2 multiwall nanotubes (NTs) is here reported over 440–940 nm wavelength range for light polarization both parallel and perpendicular to nanotube longitudinal axis. impact diameter environment on σL,extNT addressed with diameters 120 220 in suspended, sapphire-supported, PMMA-supported configurations. Measuring utmost importance given wide size dispersion intrinsic synthesis...
Recently, a new device to measure the orbital angular momentum (OAM) electronic spectrum after elastic/inelastic scattering in transmission electron microscope has been introduced. We modified theoretical framework needed describe conventional low-loss energy loss spectroscopy (EELS) experiments microscopes (TEM) study surface plasmons metallic nanostructures, allow for an OAM post selection and devise analysis of these excitations nanostructures. found that unprecedented information on...
The key to optimizing spatial resolution in a state-of-the-art scanning transmission electron microscope is the ability precisely measure and correct for optical aberrations of probe-forming lenses. Several diagnostic methods aberration measurement correction with maximum precision accuracy have been proposed, albeit often at cost relatively long acquisition times. Here, we illustrate how artificial intelligence can be used provide near-real-time diagnosis from individual Ronchigrams....
Further improvement of phase change memory devices based on Ge-Sb-Te alloys imposes the reduction active cell dimensions to nanoscale. We investigate atomic arrangement Ge(1)Sb(2)Te(4) and Ge(2)Sb(2)Te(5) nanowires. identify stacking sequence in each crystal structure by combining direct observation High Angle Annular Dark Field imaging proper simulations. find out that Ge Sb atoms randomly share same lattice sites, although this configuration is considered not stable according existing...
Films of magnetic Ni@NiO core–shell nanoparticles (NPs, core diameter d ≅ 12 nm, nominal shell thickness variable between 0 and 6.5 nm) obtained with sequential layer deposition were investigated, to gain insight into the relationships thickness/morphology, interface, properties. Different values NiO ts could be while keeping Ni size fixed, at variance conventional oxidation procedures where oxide is grown expense core. Chemical composition, morphology as-produced samples structural features...
In this paper we prove that any conformal transformation of a wave can be produced via suitably arranged cascade two, or at most four, discrete phase elements satisfying Laplace's equation. Although result is general applicability, in the case charged-matter waves it implies such transformations exactly obtained by employing only electrostatic magnetostatic elements. Furthermore, illustrate how basis for generating given integer and fractional charge multipoles, proving these used to perform...
MoS2 multi-layer flakes, exfoliated from geological molybdenite, have been exposed to high dose electron irradiation showing clear evidence of crystal lattice and stoichiometry modifications. A massive surface sulfur depletion is induced together with the consequent formation molybdenum nanoislands. It found that a nanometric amorphous carbon layer, unwillingly deposited during transmission microscope experiments, prevents In absence grains proceeds both on top bottom surfaces flake. If...
We report on the fabrication and electrical characterization of phase change memory (PCM) devices formed by In3Sb1Te2 chalcogenide nanowires (NWs), with diameters as small 20 nm. The NWs were self-assembled metal organic chemical vapor deposition via vapor–liquid–solid method, catalyzed Au nanoparticles. Reversible well reproducible switching between low high resistance states was demonstrated. conduction mechanism state investigated according to a trap-limited model for transport in...
A convolutional neural network is used to align an orbital angular momentum sorter in a transmission electron microscope. The method demonstrated using simulations and experiments. As result of its accuracy speed, it offers the possibility real-time tuning other optical devices beam shaping configurations.