A5018662253- Semiconductor materials and devices
- 2D Materials and Applications
- Electron and X-Ray Spectroscopy Techniques
- Graphene research and applications
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Electronic and Structural Properties of Oxides
- Catalysis and Hydrodesulfurization Studies
- Semiconductor materials and interfaces
- Ion-surface interactions and analysis
- MXene and MAX Phase Materials
- Electrocatalysts for Energy Conversion
- Metal and Thin Film Mechanics
- Lignin and Wood Chemistry
- Dielectric materials and actuators
- Advanced Memory and Neural Computing
- Copper Interconnects and Reliability
- Catalysis for Biomass Conversion
- Topological Materials and Phenomena
- Nanowire Synthesis and Applications
- Molecular Junctions and Nanostructures
- Conducting polymers and applications
- Integrated Circuits and Semiconductor Failure Analysis
- Graphene and Nanomaterials Applications
- ZnO doping and properties
Pennsylvania State University
2010-2025
Character
2002-2023
DEVCOM Army Research Laboratory
2022
Millennium Engineering and Integration (United States)
2018-2020
Oregon State University
2020
Messiah University
2020
The University of Texas at Dallas
2019-2020
North Carolina State University
2020
University of North Carolina at Chapel Hill
2020
Evans Analytical Group (United States)
2007
n-type field effect transistors (FETs) based on two-dimensional (2D) transition-metal dichalcogenides (TMDs) such as MoS2 and WS2 have come close to meeting the requirements set forth in International Roadmap for Devices Systems (IRDS). However, p-type 2D FETs are dramatically lagging behind performance standards. Here, we adopt a three-pronged approach that includes contact engineering, channel length (Lch) scaling, monolayer doping achieve high synthetic WSe2. Using electrical measurements...
Abstract Oxidation reactions of iron sulfide‐bearing aggregates have been increasingly recognized as a significant cause concrete deterioration worldwide. Yet there is lack mitigation strategies to control the reactions. This work investigates effectiveness nitrate‐ and nitrite‐based admixtures in inhibiting dissolution sulfides (pyrrhotite pyrite) highly alkaline environments, first step deleterious concrete. Although addition nitrate was not found exhibit profound influence, use nitrite...
There has been a considerable effort in the past decade to incorporate nitrogen into SiO2 order improve electrical properties of ultrathin (2–10 nm) gate oxides. Process conditions affect concentration, coordination, and depth distribution which, turn, properties. X-ray photoelectron spectroscopy (XPS) is particularly well suited obtaining coordination and, lesser extent, concentration thin oxynitride films. To date, at least four different coordinations have reported XPS literature, all...
Sample preparation and mounting are important aspects of x-ray photoelectron spectroscopy (XPS) analysis. New users do not know many techniques that familiar to analysts with years experience, these observations “tricks the trade” typically published. This article is intended convey experience authors in this field who have creatively analyzed a wide range samples. Samples can include solids, powders, fibers, porous even liquids. information also anyone submitting samples for analysis, since...
Chemical reductions of lignin are useful to remove oxygen and create product slates that can function as renewable platform molecules for new fuels chemicals. Catalytic transfer hydrogenolysis (CTH) is an underexplored method reduce obviates the use dangerous nonrenewable hydrogen gas. While noble metals used extensively catalysts hydrogenation, sustainability remains a major challenge their deployment. In this work, we synthesized mixed-metal oxides earth-abundant Co Ni characterized using...
Hexagonal boron nitride (hBN) has long been considered chemically inert due to its wide bandgap and robust covalent bonds. Its inertness hinders hBN from functionalization for energy conversion applications. A question arising is whether it possible make reactive. Here, we report cryomilling in liquid N2, as an effective strategy activate the chemical reactivity of by engineering different vacancies produce defective-BN (d-BN). The local probed photoluminescence (PL) emissions electron spin...
As the Rp of ion implants steadily decreases an ever-increasing percentage implant species lies in oxide layer and is, therefore, not electrically active. For this reason, it is important to have analytical techniques capable accurately measuring thickness ultrathin layers. A round-robin study was performed on a series SiO2 films ranging from 0.3 20 nm order evaluate advantages disadvantages five commonly used techniques. High-resolution cross-section transmission electron microscopy (TEM)...
The stoichiometry of a series low pressure chemical vapor deposition deposited SiOx films was determined using x-ray photoelectron spectroscopy (XPS) by two different methods. first, more traditional, method involved applying relative sensitivity factors to the integrated O 1s and Si 2p peaks, taking into consideration differences in photoemission probabilities oxidized elemental silicon. In second spectra were curve fit five peaks corresponding Si0+SiH (99.4 eV), Si1+ (100.3 Si2+ (101.2...
Polymer nanocomposites containing carbon nanomaterials such as black, nanotubes, and graphene exhibit exceptional mechanical, thermal, electrical, gas-barrier properties. Although the materials property benefits are well established, controlling dispersion of in polymer matrixes during processing is still a difficult task using current methods. Here, we report simple, yet versatile method to simultaneously achieve reduction oxide (GO) polymerization styrene create reduced oxide/poly(styrene)...
Molybdenum disulfide, a two-dimensional transition metal dichalcogenide, was analyzed using in situ x-ray photoelectron spectroscopy (XPS). The XPS spectra obtained from fresh surface which exfoliated and annealed ultrahigh vacuum include survey scan, high resolution of O 1s, C Mo 3d, S 2s, 2p, 3p, 4p, 3s, the valence band. Quantitative analysis indicates sulfur deficient composition MoS1.8, impurities were below detection limit.
Zinc selenide (ZnSe) was analyzed using x-ray photoelectron spectroscopy (XPS). A small notched rod fractured in the XPS vacuum system at 6 × 10−4 Pa to create an oxygen-free surface for analysis. Spectral regions Zn 2p, 3d, LMM, O 1s, C Se 3p, and LMM valence band were acquired. The presence of carbon could not be confirmed due interferences between 1s KLL 3s. It is believed that any present very low.
Scandium nitride (ScN) by plasma-enhanced atomic layer deposition (PEALD) was demonstrated on silicon (100), sapphire (0001), and magnesium oxide (001) substrates under ultrahigh purity conditions using a new Sc precursor, bis(ethylcyclopentadienyl)scandium-chloride [ClSc(EtCp)2]. Out-of-plane x-ray diffraction patterns indicated single-crystal, cubic phase ScN deposited at 215 °C (0001) substrates, whereas phi-scans confirmed epitaxial growth. The thin films grown with native were...
The implementation of stereolithography (SLA) for fabricating 3D-structured polymer-derived ceramics (PDCs) has greatly improved the resolution, manufacturing potential, and widespread capability to produce complicated component geometries in ceramic materials. However, different material systems impose challenges traditional UV SLA photo-cross-linking process due a narrow window selection requirements-UV transparency, degradation resistance, ability support photoinduced radical curing...
Unique functionalities can arise when 2D materials are scaled down near the monolayer limit. However, in with strong van der Waals bonds between layers, such as SnSe, maintaining stoichiometry while limiting vertical growth is difficult. Here, we describe how self-limiting promote of SnSe thin films deposited by molecular beam epitaxy. The Pnma phase was stabilized over a broad range Sn : Se flux ratios from 1 to 5. Changing ratio does not affect film stoichiometry, but influences...
Tungsten diselenide (WSe2) was analyzed using x-ray photoelectron spectroscopy. A freshly exfoliated, oxygen-free flake analyzed. Spectral regions for O 1s, W 4d, 4f, 5p, Se 3d and an extended region encompassing 3p, 3s, LMM, C 1s were acquired along with the valence band. Bulk quantitative analyses by fluorescence diffraction indicated material stoichiometric phase pure, respectively.
We demonstrate an N2 plasma-enhanced process for inducing (0001)-oriented ALD-grown AlN on planar substrates. evaluate the impact of {111}-textured Pt as a growth template, precursor chemistry, dose time, stress-engineered substrates, inductively coupled plasma conditions film bombardment during growth, and ALD equipment configurations. The thin transverse piezoelectric coefficient e31,f determined from measurements microelectromechanical system cantilevers coated by PEALD is reported to be...
Ultrahigh purity (UHP) reactor conditions provide a process environment for growth of nitride thin films with low oxygen content by plasma-enhanced atomic layer deposition (PEALD). In particular, UHP correspond to partial pressures below 10−8 Torr impurities within the PEALD limit incorporation before, during, and after film growth. this article, we identify various sources background species describe measures taken obtain conditions. For example, in situ ellipsometry results are presented...
Quantification of spectral data from X‐ray photoelectron spectroscopy is frequently done using relative sensitivity factors (RSFs) provided by instrument or software vendors. Understanding the key that impact amount signal observed a given peak has improved substantially over past 30+ years, which permits calculation RSFs first principles. Here, we have examined series in vacuo fractured silicate glass samples covering wide range elemental compositions allow determination empirical for peaks...
A parallel fluorescent screening method was used to evaluate active catalysts for the alkaline hydrogen oxidation reaction (HOR). library of 1584 catalyst samples containing single element, binary, and ternary combinations prepared in high-throughput fashion from 12 elements (Pt, Ag, Au, Co, Cu, Fe, Hg, Ni, Pb, Pd, Rh, Sn) screened their HOR onset potentials an electrolyte. One most alloys, Pt6Sn4, tested polymer membrane fuel cell produced a power density 132 mW/(cm2·mg Pt) compared with...
Materials that catalyze the hydrogen evolution reaction (HER) are important for producing H2 as a zero-emission fuel. Ru-based materials becoming increasingly studied HER catalysts because they often perform comparably to Pt, benchmark this reaction. Despite availability of growing number high surface area catalysts, these can be challenging synthesize. In contrast, bulk readily synthesized by using established solid-state chemistry techniques. While compounds undesirable practical their low...