A5042562279- 2D Materials and Applications
- Graphene research and applications
- Perovskite Materials and Applications
- Diamond and Carbon-based Materials Research
- Chalcogenide Semiconductor Thin Films
- Semiconductor materials and interfaces
- MXene and MAX Phase Materials
- Nanowire Synthesis and Applications
- Conducting polymers and applications
- Anodic Oxide Films and Nanostructures
- Gas Sensing Nanomaterials and Sensors
- Advanced materials and composites
- Metal and Thin Film Mechanics
- Advanced Nanomaterials in Catalysis
- Advanced biosensing and bioanalysis techniques
- High-pressure geophysics and materials
- Quantum Dots Synthesis And Properties
- Phase-change materials and chalcogenides
- Silicon Nanostructures and Photoluminescence
- High-Temperature Coating Behaviors
- Radiation Effects in Electronics
- Solid-state spectroscopy and crystallography
- Luminescence and Fluorescent Materials
- Modular Robots and Swarm Intelligence
- Electrochemical sensors and biosensors
University of North Texas
2020-2024
Nanosheets of silicene, a 2D material made silicon atoms, have great potential for use in next-generation electronic and optoelectronic devices due to their unique properties. However, issues the large-scale production silicene nanosheets degradation still present challenges these applications. Here, we report method obtain large quantities single few-layer thick silicene/silicene oxide ("Si nanosheets") from calcium disilicide (CaSi2). We also show that experience oxidation air are highly...
Silicon nanotubes (Si NTs) have a unique structure among the silicon nanostructure family, which is useful for diverse applications ranging from therapeutics to lithium storage/recycling. Their well-defined and high surface area make them ideal sensing applications. In this work, we demonstrate formation of Au nanoparticles (NPs) functionalized with 4-Mercaptophenylboronic acid (MPBA) on porous Si NTs (pSi fabricated using ZnO nanowires as template. The system was characterized, proposed...
Abstract Realizing stimulated emission from defects in 2D‐layered semiconductors has the potential to enhance sensitivity of characterizing their defects. However, layered materials presents a different set challenges carrier lifetime and energy level design is not achieved so far. Here, photoluminescence (PL) spectroscopy, Raman first‐principles theory are combined reveal an anomalous PL intensity–temperature relation strong polarization effects at defect peak annealed multilayer MoS 2 ,...
Silicon telluride (Si2Te3) and many other tellurium-containing compounds show emergent Raman peaks located at ∼120 ∼140 cm–1 as they age. The origin of these two is controversial in the literature has been attributed to myriad causes such intrinsic modes materials, surface oxidation, defects, double resonances, tellurium precipitates. nature led misidentification highly degraded materials pristine misinterpretation changes spectra. Here, we present a comprehensive multimodal study on Si2Te3...
Perovskite nanowires encapsulated inside nickel oxide nanotubes were studied. This unique structure showed a stable and efficient electroluminescence for potential LED applications.
Herein, photoluminescence (PL) and fluorescence lifetime imaging (FLIM) in multilayer MoSe 2 are studied. Strain‐activated stimulated emission via defect levels under laser excitation is observed, for the first time defects of transition metal dichalcogenides. The indicated by a threshold behavior PL intensity with respect to intensity, strong polarization effects, achieved population inversion difference lifetimes two competing excited states, localization zone as observed FLIM. presented...
Abstract It is reported that chemical vapor deposition (CVD) grown bilayer (BL) MoS 2 films are significantly more structurally stable in ambient air than CVD‐grown monolayer (ML) have been to degrade air. The authors present atomic force microscopy (AFM) images of preheated and as‐grown ML multilayer after exposure for periods up years. AFM show that, air, BL thicker‐layer do not exhibit the growth dendrites characteristic degradation. Dendrites observed stop at ML‐BL boundary. Raman...
Self-assembly of block copolymers (BCPs) provides a unique platform for producing periodic and orderly structured soft materials nanometer scale. The kinetics the assembly process defines accessible range morphologies allows formation asymmetric hierarchies. Here, self-assembly ultrahigh-molecular-weight BCPs with relatively slow molecular chain dynamics is used to fabricate metastable structure. More specifically, kinetically trapped solvent vapor annealing applied...
The layer edge states or low energy state (LES) in 2D hybrid organic–inorganic perovskites demonstrate a prolonged carrier lifetime for better performance of optoelectronic devices. However, the fundamental understanding LES is still inconclusive. Herein, photoluminescence (PL) study Ruddlesden–Popper presented with n = 2 and 3 from their cleaved cross sections that are more stable than natural edge. PL measurements clearly observe reversible, irreversible surface relaxations (case I case...
Perovskites with reduced dimensions are very attractive for LED applications due to their improved stability and efficient energy transfer. This is exemplified by 2D perovskites reported in the literature, predominantly either Dion-Jacobson or Ruddlesden–Popper systems, which typically use long chain alkyl moieties as spacers order form layers. Here, we report an approach uses inorganic material─silicene─as a template two-dimensional quantum-confined CsPbBr3 (qc-CsPbBr3) layers of less than...
Abstract Controlling diamond structures with nanometer precision is fundamentally challenging owing to their extreme and far‐from‐equilibrium synthetic conditions. State‐of‐the‐art techniques, including detonation, chemical vapor deposition, mechanical grinding, high‐pressure‐high‐temperature synthesis, yield nanodiamond particles a broad distribution of sizes. Despite many efforts, the direct synthesis nanodiamonds precisely controlled diameters remains elusive. Here geochemistry‐inspired...
Using a scanning electron microscope, we irradiate graphene drums with electrons at an energy of 20 keV and dosage about 1.58 × 1017 electrons/cm2. The consist exfoliated in ambient air over holes having diameter 4.6 μm etched into SiO2 substrate. After irradiation, observe that the drum’s suspended monolayer (ML) region has ratio Raman D peak height, ID, to G IG, as high 6.3. In contrast, supported ML on substrate ID/IG 0.49. Previous studies have shown containing can leak vacuum low rate....
Silicon telluride (Si2Te3) has emerged as one of the many contenders for 2D materials ideal fabrication atomically thin devices. Despite progress which been made in electric and optical properties silicon telluride, much work is still needed to better understand this material. We report here on Raman study Si2Te3degradation under both annealing andin situheating with a laser. Both processes caused pristine Si2Te3to degrade into tellurium oxide air absence protective coating. A previously...
We report on the properties of defects in exfoliated graphene SiO2 produced by electron irradiation at 25 keV and dosages from 4.96 × 1015 to 9.56 1017 electrons/cm2. With increasing dosage, exhibits two-stage amorphization trajectory reported for Ar ion bombardment graphene. Initially, ratio D-peak height, ID, G peak IG, increases as new are formed. In second stage, ID/IG decreases cover most sample. we find that full width half maximum Raman 2D, D, peaks 3, 6 cm−1, respectively. These...
Non-lithographic routes to creating curved, non-planar nanostructures and associated interfaces are appealing from both fundamental scientific applied technological perspectives. For some time, we have been interested in the creation of hollow Si nanotubes with sensitive control inner tube diameter, wall thickness, length using sacrificial etching zinc oxide (ZnO) Si-coated ZnO nanowires (NWs). With suitable nanotube thinness (< 10 nm), porosity sidewall morphology is retained as well...
We report that chemical vapor deposition (CVD) grown bilayer and thicker-layered MoS2 are structurally optically stable under ambient conditions, in comparison to CVD-grown monolayer other transition metal dichalcogenides (TMDs) have been reported degrade the same hindering their many potential applications. present atomic force microscopy (AFM), Raman photoluminescence (PL) spectroscopy measurements of as-grown preheated multilayer after exposure conditions for periods up 2 years. The AFM...