A5055783671- Graphene research and applications
- Carbon Nanotubes in Composites
- 2D Materials and Applications
- Nanowire Synthesis and Applications
- MXene and MAX Phase Materials
- Force Microscopy Techniques and Applications
- Perovskite Materials and Applications
- Nanotechnology research and applications
- Semiconductor materials and interfaces
- Mechanical and Optical Resonators
- Molecular Junctions and Nanostructures
- Supercapacitor Materials and Fabrication
- Conducting polymers and applications
- Electron and X-Ray Spectroscopy Techniques
- Boron and Carbon Nanomaterials Research
- Advanced Sensor and Energy Harvesting Materials
- Nanopore and Nanochannel Transport Studies
- Diatoms and Algae Research
- Electronic and Structural Properties of Oxides
- Chalcogenide Semiconductor Thin Films
- Surface and Thin Film Phenomena
- Surface Modification and Superhydrophobicity
- Machine Learning in Materials Science
- GaN-based semiconductor devices and materials
- Advanced Memory and Neural Computing
Northeastern University
2016-2025
Quantum Devices (United States)
2024
Universidad del Noreste
2019-2023
Los Alamos National Laboratory
2021
Center for Integrated Nanotechnologies
2021
University of Utah
2021
Korea Aerospace University
2021
University of Electronic Science and Technology of China
2017-2020
Inter-University Accelerator Centre
2017
United States Department of Homeland Security
2015
We present the photodetection properties of graphene/Si heterojunctions both in photocurrent and photovoltage modes. Monolayer junctions were found to be excellent weak-signal detectors with responsivity exceeding 10(7) V/W noise-equivalent-power reaching ∼1 pW/Hz(1/2), potentially capable distinguishing materials transmittance, T = 0.9995 a 0.5 s integration time. In mode, response was remain linear over at least six decades incident power (P), tunable up 435 mA/W (corresponding photon...
Jet stream: Multi-walled carbon nanotubes grown by catalytic chemical vapor deposition were carboxylated in a two-step oxidation process. An aqueous dispersion of the functionalized was dispensed using an inkjet printer to obtain electrically conductive patterns on paper and plastic surfaces (see picture). Sheet resistivities for deposited about 40 kΩ/□ could be achieved multiple prints.
We present a scalable and facile technique for noncovalent functionalization of graphene with 1-pyrenecarboxylic acid that exfoliates single-, few-, multilayered flakes into stable aqueous dispersions. The exfoliation mechanism is established using stringent control experiments detailed characterization steps. Using the exfoliated graphene, we demonstrate highly sensitive selective conductometric sensors (whose resistance rapidly changes >10,000% in saturated ethanol vapor), ultracapacitors...
We present the fabrication and electrical characterization of a flexible hybrid composite structure using aligned multiwall carbon nanotube arrays in poly(dimethylsiloxane) (PDMS) matrix. Using lithographically patterned arrays, one can make these structures at any length scale from submicrometer levels to bulk quantities. The PDMS matrix undergoes excellent conformal filling within dense network, giving rise extremely conducting with unique electromechanical properties. demonstrate its...
Since their modern debut in 2004, 2-dimensional (2D) materials continue to exhibit scientific and industrial promise, providing a broad platform for investigation, development of nano- atomic-scale devices. A significant focus the last decade's research this field has been 2D semiconductors, whose electronic properties can be tuned through manipulation dimensionality, substrate engineering, strain, doping (Mak et al 2010 Phys. Rev. Lett. 105 136805; Zhang 2017 Sci. Rep. 7 16938; Conley 2013...
We have studied the role of defects on magnetic properties carbon materials using first-principles density functional methods. show that, while total magnetization decreases both for diamond and graphite with increase in vacancy density, more rapidly graphitic structures. The presence nitrogen nearby a is shown to produce larger macroscopic signals as compared standalone vacancy. results indicate possibility tuning by controlled defect generation doping.
The ability to synthesize high-quality samples over large areas and at low cost is one of the biggest challenges during developmental stage any novel material. While chemical vapor deposition (CVD) methods provide a promising low-cost route for CMOS compatible, large-scale growth materials, it often falls short demands in nanoelectronics optoelectronics. We present CVD synthesis single- few- layered MoS2 using direct vapor-phase sulfurization MoO2, which enables us obtain extremely...
In an earlier work, we had reported a method that enables graphene-silicon junctions to display exceptionally high photovoltaic responses, exceeding 10(7) V/W. Using completely different has recently been result in ultrahigh gain, now show these can also demonstrate giant photocurrent responsivities approach ∼ A/W. Together, mechanisms enable be dual-mode, broad-band, scalable, CMOS-compatible, and tunable photodetector operate either photovoltage or modes with responsivity values. We...
Molybdenum disulfide (MoS2) flakes can grow beyond the edge of an underlying substrate into a planar freestanding crystal. When is in form aperture, reagent-limited nucleation followed by growth facilitate direct and selective MoS2 membranes. We have found conditions under which grows preferentially across micrometer-scale prefabricated solid-state apertures silicon nitride membranes, resulting sealed membranes that are one to few atomic layers thick. investigated structure purity our...
Bottom-up assembly of two-dimensional (2D) materials into macroscale morphologies with emergent properties requires control the material surroundings, so that energetically favorable conditions direct process. MXenes, a class recently developed 2D materials, have found new applications in areas such as electrochemical energy storage, nanoscale electronics, sensors, and biosensors. In this paper, we present lateral self-assembly method for wafer-scale deposition mosaic-type MXene flake...
We present fabrication and characterization of macroscopic thin films graphene flakes, which are functionalized with 1-pyrenecarboxylic acid (PCA) laminated onto flexible transparent polydimethylsiloxane (PDMS) membranes. The noncovalently (π-stacked) functionalization PCA allows us to obtain a number unique optical molecular sensing properties that absent in pristine films, without sacrificing the conducting nature graphene. PCA-graphene-PDMS hybrid structure can block 70-95% ultraviolet...
We report on the performance of supercapacitor devices fabricated using 1-pyrenecarboxylic acid (PCA)-functionalized graphene electrodes. The specific capacitances obtained (using 6 M KOH aqueous solution as an electrolyte) was found to be order magnitude higher than nonfunctionalized electrodes (∼30 and ∼200 F/g for pure PCA-functionalized electrodes, respectively). analysis electrochemical impedance spectroscopy equivalent circuit modeling well electrolyte wettability measurements shows a...
Semiconducting 2D materials, like transition metal dichalcogenides (TMDs), have gained much attention for their potential in opto-electronic devices, valleytronic schemes, and semi-conducting to metallic phase engineering. However, graphene other atomically thin they lose key properties when placed on a substrate silicon, including quenching of photoluminescence, distorted crystalline structure, rough surface morphology. The ability protect these monolayer TMDs, such as molybdenum disulfide...
The use of micro-/nanoelectromechanical resonators for the room temperature detection electromagnetic radiation at infrared frequencies has recently been investigated, showing thermal capabilities that could potentially outperform conventional microbolometers. scaling device thickness in nanometer range and achievement high absorption such a subwavelength thickness, without sacrificing electromechanical performance, are two key challenges implementation fast, high-resolution resonant...
Mapping biocurrents at both microsecond and single-cell resolution requires the combination of optical imaging with innovative electrophysiological sensing techniques. Here, we present transparent electrophysiology electrodes interconnects made gold (Au) nanomesh on flexible substrates to achieve such measurements. Compared previously demonstrated indium tin oxide (ITO) graphene electrodes, ones from Au possess superior properties including low electrical impedance, high transparency, good...
Abstract Quantum technologies are poised to move the foundational principles of quantum physics forefront applications. This roadmap identifies some key challenges and provides insights on material innovations underlying a range exciting technology frontiers. Over past decades, hardware platforms enabling different have reached varying levels maturity. has allowed for first proof-of-principle demonstrations supremacy, example computers surpassing their classical counterparts, communication...
Abstract The Materials Genome Initiative (MGI) has streamlined the materials discovery effort by leveraging generic traits of materials, with focus largely on perfect solids. Defects such as impurities and perturbations, however, drive many attractive functional properties materials. rich tapestry charge, spin, bonding states hosted defects are not accessible to elements crystals, can thus be viewed another class “elements” that lie beyond periodic table. Accordingly, a Defect (DGI)...
We report the effect of low-energy (1 keV) electron beam irradiation on gated, three-terminal devices constructed from metallic single-walled carbon nanotubes. Pristine devices, which exhibited negligible gate voltage response at room temperature and single-electron transistor characteristics low temperatures, when exposed to an beam, ambipolar field (room temperature) (low characteristics. This metal−semiconductor transition is attributed inhomogeneous electric fields arising charging...
We report an air-assisted chemical vapor deposition (CVD) method for the synthesis of super-long carbon nanotube (CNT) bundles. By mixing a small amount air in phase catalyst CVD process, lifetime can be dramatically increased, and extremely long dense aligned CNT bundles up to 1.5 cm achieved. Electron microscopy characterization shows that injection does not damage structures. Further, we have estimated individual ultra-long CNTs carry moderate current densities ∼10(5) A cm(-2), indicating...
A large variety of interconnected nanowire/nanotube (NW/NT) and nanotube/nanowire/nanotube (NT/NW/NT, see picture) hybrid architectures with branched topology have been prepared using a combinatorial process electrodepositing nanowires in the channels anodic aluminum oxide templates, selectively etching part deposited nanowires, growing nanotubes remaining empty on ends nanowires.