A5058362762- Ferroelectric and Piezoelectric Materials
- Perovskite Materials and Applications
- Acoustic Wave Resonator Technologies
- Electronic and Structural Properties of Oxides
- Ion-surface interactions and analysis
- Advanced Memory and Neural Computing
- Force Microscopy Techniques and Applications
- Photorefractive and Nonlinear Optics
- Conducting polymers and applications
- Solid-state spectroscopy and crystallography
- Multiferroics and related materials
- Graphene research and applications
- Transition Metal Oxide Nanomaterials
- Analytical Chemistry and Sensors
- Mass Spectrometry Techniques and Applications
- Catalytic Processes in Materials Science
- Spectroscopy Techniques in Biomedical and Chemical Research
- Gas Sensing Nanomaterials and Sensors
- Ferroelectric and Negative Capacitance Devices
- Nanopore and Nanochannel Transport Studies
- Quantum Dots Synthesis And Properties
- Magnetic and transport properties of perovskites and related materials
- 2D Materials and Applications
- Electrocatalysts for Energy Conversion
- Advanced Electron Microscopy Techniques and Applications
Oak Ridge National Laboratory
2016-2025
Center for Nanophase Materials Sciences
2015-2025
Stanford University
2024
SLAC National Accelerator Laboratory
2024
University of Tennessee at Knoxville
2018-2019
Institute of Molecular Functional Materials
2017-2018
Material Sciences (United States)
2018
Oak Ridge Associated Universities
2017-2018
Institute of Physics
2016
National Academy of Sciences of Ukraine
2016
Abstract Metabolic reprogramming in cancer and immune cells occurs to support their increasing energy needs biological tissues. Here we propose Single Cell Spatially resolved (scSpaMet) framework for joint protein-metabolite profiling of single male human tissues by incorporating untargeted spatial metabolomics targeted multiplexed protein imaging a pipeline. We utilized the scSpaMet profile cell types metabolomic maps 19507, 31156, 8215 lung cancer, tonsil, endometrium tissues,...
Two-dimensional (2D) single-layer MoS2 nanosheets are demonstrated as efficient photocatalysts for hydrogen evolution reaction (HER) from water reduction, thanks to specific in-plane heterojunctions constructed in the monolayer. These functional formed among different phases of chemically exfoliated monolayers: semiconducting 2H, metallic 1T, and quasi-metallic 1T′ phases. The proportion three can be systematically controlled via thermal annealing nanosheets. Interestingly, a volcano...
Abstract Development of devices and structures based on the layered 2D materials critically hinges capability to induce, control tailor electronic, transport optoelectronic properties via defect engineering, much like doping strategies have enabled semiconductor electronics forging introduction iron age. Here, we demonstrate use a scanning helium ion microscope (HIM) for tailoring functionality single layer MoSe 2 locally decipher associated mechanisms at atomic level. We He + beam...
Optoelectronic devices based on metal halide perovskites, including solar cells and light-emitting diodes, have attracted tremendous research attention globally in the last decade. Due to their potential achieve high carrier mobilities, organic-inorganic hybrid perovskite materials can enable high-performance, solution-processed field-effect transistors (FETs) for next-generation, low-cost, flexible electronic circuits displays. However, performance of FETs is hampered predominantly by...
Abstract Mixed cesium‐ and formamidinium‐based metal halide perovskites (MHPs) are emerging as ideal photovoltaic materials due to their promising performance improved stability. While theoretical predictions suggest that a larger composition ratio of Cs (≈30%) aids the formation pure photoactive α‐phase, high performances can only be realized in MHPs with moderate ratios. In fact, elemental mixing solution result chemical complexities non‐equilibrium phases, causing inhomogeneities...
We report on polarization switching properties of thin flakes van der Waals ferrielectric CuInP2S6. observe mesoscale domains, ferroelectric switching, and the Curie temperature above 299 K down to a thickness ∼50 nm. However, electromechanical response is progressively suppressed below 50 nm, vanishes at room ∼10 Though larger than single layer, 10 nm still very small value compared expectations for an intrinsic semiconductor. therefore propose model doped surface layer that screens...
We demonstrate that UV-light activation of polycrystalline ZnO films on flexible polyimide (Kapton) substrates can be used to detect and differentiate between environmental changes in oxygen water vapor. The in-plane resistive impedance properties films, fabricated from bacteria-derived ZnS nanoparticles, exhibit unique capacitive responses O
Molybdenum nitride (Mo–N) catalysts have shown promising activity and stability for the oxygen reduction reaction (ORR) in acid. However, effect of (O) incorporation (from synthesis, catalysis, or exposure to air) on their remains elusive. Here, we use reactive sputtering synthesize three compositions thin-film extensive materials characterization investigate depth-dependent structure incorporated O. We show that as-deposited Mo–N films are highly oxidized both at surface (>30% O) bulk...
Abstract Metal, nitrogen‐doped carbon materials have attracted interest as heterogenous catalysts that contain MN x active sites are analogous to molecular catalysts. Of particular is Ni,N‐doped carbon, a catalyst for the electrochemical reduction of CO 2 CO. Critical understanding these proof single atomic and characterization environment surrounding metal atom; however, directly probing this coordination remains challenging. This challenge addressed by combining scanning transmission...
Abstract Unique optoelectronic, electronic, and sensing properties of hybrid organic–inorganic perovskites (HOIPs) are underpinned by the complex interactions between electronic ionic states. Here, photoinduced field ion migration in HOIPs is directly observed. Using newly developed local probe time‐resolved techniques, more significant CH 3 NH + than I − /Br unveiled. It found that light illumination only induces but not migration. By observing temporal changes bias‐induced device...
Piezoelectric force microscopy (PFM) and Raman confocal have been used for studying the nanodomain structures in congruent LiNbO3 LiTaO3 crystals. The high-resolution images at surface were observed via PFM. has visualization of bulk layer-by-layer scanning various depths. It shown experimentally that obtained different depths correspond to domain polar moments: deeper nanodomain, earlier moment. Such a correlation was applied reconstruction evolution with charged walls. studied highly...
Polarization switching in ferroelectric materials is governed by a delicate interplay between bulk polarization dynamics and screening processes at surfaces domain walls. Here we explore the mechanism of tip-induced nonpolar cuts uniaxial ferroelectrics. In this case, in-plane component vector switches, allowing for detailed observations resultant morphologies. We observe surprising variability morphologies stemming from fundamental instability formed charged wall associated electric...
Strongly correlated vanadium dioxide (VO2) is one of the most promising materials that exhibits a temperature-driven, metal-insulator transition (MIT) near room temperature. The ability to manipulate MIT at nanoscale offers both insight into understanding energetics phase and potential for nanoelectronic devices. In this work, we study electrochemical modifications in epitaxial VO2 thin films using combined approach with scanning probe microscopy (SPM) theoretical calculations. We find...
The role of trivalent rare-earth dopants on the cerium oxidation state has been systematically studied by in situ photoemission spectroscopy with synchrotron radiation for 10 mol % doped epitaxial ceria films. It was found that dopant rare-earths smaller ionic radius foster formation Ce3+ releasing stress strength induced cation substitution. With a decrease from La3+ to Yb3+, out-of-plane axis parameter crystal lattice decreases without introducing macroscopic defects. high quality our...
In the last several decades, ferroelectrics have attracted much attention as perspective materials for nonlinear optics and data storage devices. Scanning probe microscopy (SPM) has emerged a powerful tool both studies of domain structures with nanoscale spatial resolution writing isolated nanodomains by local application electric field. Quantitative analysis observed behavior requires understanding role environmental factors on imaging switching process. Here, we study influence relative...
Noninvasive in situ nanoscale imaging liquid environments is a current imperative the analysis of delicate biomedical objects and electrochemical processes at reactive liquid–solid interfaces. Microwaves few gigahertz frequencies offer photons with energies ≈10 μeV, which can affect neither electronic states nor chemical bonds condensed matter. Here, we describe an implementation scanning near-field microwave microscopy for liquids using ultrathin molecular impermeable membranes separating...
In low purity crystals, (bottom) smaller more disordered crystallite sizes lead to increased charge trapping, compared high (top).