scholarly journals 0D Nanocrystals as Light-Driven, Localized Charge Injection Sources for the Contactless Manipulation of Atomically Thin 2D Materials

2020 ◽  
Author(s):  
Ilka Kriegel ◽  
Michele Ghini ◽  
Emanuil Sashev Yanev ◽  
Christoph Kastl ◽  
Adam W. Jansons ◽  
...  
Keyword(s):  
Driving Force ◽  
Carrier Density ◽  
2D Materials ◽  
Charge Injection ◽  
Long Distance ◽  
Nanoscale Device ◽  
2D Material ◽  
Key Innovation ◽  
Ultraviolet Illumination ◽  
Electrostatic Gating

We report a new localized and electrodeless charge injection scheme that quasi-permanently modifies monolayer (1L-)MoS2 doping levels to extents competing with electrostatic gating. The key innovation is to use Sn-doped In2O3 (ITO) nanocrystals (NCs) as contactless light-driven charge injection sources triggered solely by light. Each nanocrystal can store and transfer multiple charges after ultraviolet illumination within the diffraction limited laser spot. This results in reductions in carrier density in the underlying 1L-MoS2 up to 1×1013 cm-2 and is observed throughout the extent of the 2D material flake. The long-distance charge separation proliferates up to 40 µm away from the localized charge injection and persists over months. The apparent driving force for carrier relocation is the initial inhomogeneous electronic landscape of the 2D material. These studies demonstrate a novel all-optically controlled tool to locally inject carriers with sub-micrometer precision. This new ability allows us to extract important aspects of inhomogeneity in 2D materials undisturbed by bulky electronic contacts and indicates that local 2D material manipulation can serve as a key element for novel nanoscale device design.

scholarly journals 0D Nanocrystals as Light-Driven, Localized Charge Injection Sources for the Contactless Manipulation of Atomically Thin 2D Materials

2020 ◽  
Author(s):  
Ilka Kriegel ◽  
Michele Ghini ◽  
Emanuil Sashev Yanev ◽  
Christoph Kastl ◽  
Adam W. Jansons ◽  
...  
Keyword(s):  
Driving Force ◽  
Carrier Density ◽  
2D Materials ◽  
Charge Injection ◽  
Long Distance ◽  
Nanoscale Device ◽  
2D Material ◽  
Key Innovation ◽  
Ultraviolet Illumination ◽  
Electrostatic Gating

We report a new localized and electrodeless charge injection scheme that quasi-permanently modifies monolayer (1L-)MoS2 doping levels to extents competing with electrostatic gating. The key innovation is to use Sn-doped In2O3 (ITO) nanocrystals (NCs) as contactless light-driven charge injection sources triggered solely by light. Each nanocrystal can store and transfer multiple charges after ultraviolet illumination within the diffraction limited laser spot. This results in reductions in carrier density in the underlying 1L-MoS2 up to 1×1013 cm-2 and is observed throughout the extent of the 2D material flake. The long-distance charge separation proliferates up to 40 µm away from the localized charge injection and persists over months. The apparent driving force for carrier relocation is the initial inhomogeneous electronic landscape of the 2D material. These studies demonstrate a novel all-optically controlled tool to locally inject carriers with sub-micrometer precision. This new ability allows us to extract important aspects of inhomogeneity in 2D materials undisturbed by bulky electronic contacts and indicates that local 2D material manipulation can serve as a key element for novel nanoscale device design.

scholarly journals Topological vectors as a fingerprinting system for 2D-material flake distributions

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Joyce C. C. Santos ◽  
Mariana C. Prado ◽  
Helane L. O. Morais ◽  
Samuel M. Sousa ◽  
Elisangela Silva-Pinto ◽  
...  
Keyword(s):  
Distribution Function ◽  
2D Materials ◽  
Shape Parameters ◽  
Representation System ◽  
Statistical Characterization ◽  
2D Material ◽  
Fast Pace ◽  
Parameter Distributions

AbstractThe production of 2D material flakes in large quantities is a rapidly evolving field and a cornerstone for their industrial applicability. Although flake production has advanced in a fast pace, its statistical characterization is somewhat slower, with few examples in the literature which may lack either modelling uniformity and/or physical equivalence to actual flake dimensions. The present work brings a methodology for 2D material flake characterization with a threefold target: (i) propose a set of morphological shape parameters that correctly map to actual and relevant flake dimensions; (ii) find a single distribution function that efficiently describes all these parameter distributions; and (iii) suggest a representation system—topological vectors—that uniquely characterizes the statistical flake morphology within a given distribution. The applicability of such methodology is illustrated via the analysis of tens of thousands flakes of graphene/graphite and talc, which were submitted to different production protocols. The richness of information unveiled by this universal methodology may help the development of necessary standardization procedures for the imminent 2D-materials industry.

scholarly journals Gate-tunable plasmons in mixed-dimensional van der Waals heterostructures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sheng Wang ◽  
SeokJae Yoo ◽  
Sihan Zhao ◽  
Wenyu Zhao ◽  
Salman Kahn ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carrier Density ◽  
Electromagnetic Interaction ◽  
Luttinger Liquid ◽  
Fundamental Physics ◽  
Metallic Structures ◽  
One Dimensional ◽  
Figures Of Merit ◽  
Electrostatic Gating ◽  
Plasmon Dispersion

AbstractSurface plasmons, collective electromagnetic excitations coupled to conduction electron oscillations, enable the manipulation of light–matter interactions at the nanoscale. Plasmon dispersion of metallic structures depends sensitively on their dimensionality and has been intensively studied for fundamental physics as well as applied technologies. Here, we report possible evidence for gate-tunable hybrid plasmons from the dimensionally mixed coupling between one-dimensional (1D) carbon nanotubes and two-dimensional (2D) graphene. In contrast to the carrier density-independent 1D Luttinger liquid plasmons in bare metallic carbon nanotubes, plasmon wavelengths in the 1D-2D heterostructure are modulated by 75% via electrostatic gating while retaining the high figures of merit of 1D plasmons. We propose a theoretical model to describe the electromagnetic interaction between plasmons in nanotubes and graphene, suggesting plasmon hybridization as a possible origin for the observed large plasmon modulation. The mixed-dimensional plasmonic heterostructures may enable diverse designs of tunable plasmonic nanodevices.

J and CTOD Based Tensile Strain Capacity Prediction for Pipelines with a Surface Crack in Girth Weld

2021 ◽  
Author(s):  
Youn-Young Jang ◽  
Nam-Su Huh ◽  
Ik-Joong Kim ◽  
Young-Pyo Kim
Keyword(s):  
Crack Initiation ◽  
Internal Pressure ◽  
Surface Crack ◽  
Driving Force ◽  
Tensile Strain ◽  
Structural Integrity ◽  
Accurate Estimation ◽  
Long Distance ◽  
Crack Driving Force ◽  
Girth Welding

Abstract Long-distance pipelines for the transport of oil and natural gas to onshore facilities are mainly fabricated by girth welding, which has been considered as a weak location for cracking. Pipeline rupture due to crack initiation and propagation in girth welding is one of the main issues of structural integrity for a stable supply of energy resources. The crack assessment should be performed by comparing the crack driving force with fracture toughness to determine the critical point of fracture. For this reason, accurate estimation of the crack driving force for pipelines with a crack in girth weld is highly required. This paper gives the newly developed J-integral and crack-tip opening displacement (CTOD) estimation in a strain-based scheme for pipelines with an internal surface crack in girth weld under axial displacement and internal pressure. For this purpose, parametric finite element analyses have been systematically carried out for a set of pipe thicknesses, crack sizes, strain hardening, overmatch and internal pressure conditions. Using the proposed solutions, tensile strain capacities (TSCs) were quantified by performing crack assessment based on crack initiation and ductile instability and compared with TSCs from curved wide plate tests to confirm their validity.

scholarly journals 2D Materials in Development of Electrochemical Point-of-Care Cancer Screening Devices

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 662 ◽  
Author(s):  
Mohsen Mohammadniaei ◽  
Huynh Vu Nguyen ◽  
My Van Tieu ◽  
Min-Ho Lee
Keyword(s):  
Cancer Screening ◽  
2D Materials ◽  
Point Of Care ◽  
Low Cost ◽  
Clinical Analysis ◽  
Cancer Diagnostics ◽  
Electrochemical Sensing ◽  
Screening Tools ◽  
Electrochemical Biosensors ◽  
2D Material

Effective cancer treatment requires early detection and monitoring the development progress in a simple and affordable manner. Point-of care (POC) screening can provide a portable and inexpensive tool for the end-users to conveniently operate test and screen their health conditions without the necessity of special skills. Electrochemical methods hold great potential for clinical analysis of variety of chemicals and substances as well as cancer biomarkers due to their low cost, high sensitivity, multiplex detection ability, and miniaturization aptitude. Advances in two-dimensional (2D) material-based electrochemical biosensors/sensors are accelerating the performance of conventional devices toward more practical approaches. Here, recent trends in the development of 2D material-based electrochemical biosensors/sensors, as the next generation of POC cancer screening tools, are summarized. Three cancer biomarker categories, including proteins, nucleic acids, and some small molecules, will be considered. Various 2D materials will be introduced and their biomedical applications and electrochemical properties will be given. The role of 2D materials in improving the performance of electrochemical sensing mechanisms as well as the pros and cons of current sensors as the prospective devices for POC screening will be emphasized. Finally, the future scopes of implementing 2D materials in electrochemical POC cancer diagnostics for the clinical translation will be discussed.

scholarly journals Supported and Suspended 2D Material-Based FET Biosensors

Electrochem ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 260-277 ◽  
Author(s):  
Nirul Masurkar ◽  
Sundeep Varma ◽  
Leela Mohana Reddy Arava
Keyword(s):  
Field Effect Transistor ◽  
Electrochemical Biosensor ◽  
2D Materials ◽  
Atomic Layer ◽  
Fabrication Technology ◽  
Semiconducting Materials ◽  
Biomolecule Detection ◽  
2D Material ◽  
2D Nanomaterials ◽  
Effect Transistor

Field Effect Transistor (FET)-based electrochemical biosensor is gaining a lot of interest due to its malleability with modern fabrication technology and the ease at which it can be integrated with modern digital electronics. To increase the sensitivity and response time of the FET-based biosensor, many semiconducting materials have been categorized, including 2 dimensional (2D) nanomaterials. These 2D materials are easy to fabricate, increase sensitivity due to the atomic layer, and are flexible for a range of biomolecule detection. Due to the atomic layer of 2D materials each device requires a supporting substrate to fabricate a biosensor. However, uneven morphology of supporting substrate leads to unreliable output from every device due to scattering effect. This review summarizes advances in 2D material-based electrochemical biosensors both in supporting and suspended configurations by using different atomic monolayer, and presents the challenges involved in supporting substrate-based 2D biosensors. In addition, we also point out the advantages of nanomaterials over bulk materials in the biosensor domain.

Multifield-tunable magneto-optical effects in electron- and hole-doped nitrogen–graphene crystals

2019 ◽  
Vol 7 (11) ◽  
pp. 3360-3368 ◽  
Author(s):  
Xiaodong Zhou ◽  
Fei Li ◽  
Yanxia Xing ◽  
Wanxiang Feng
Keyword(s):  
2D Materials ◽  
Optical Devices ◽  
Strain Fields ◽  
2D Material ◽  
Optical Effects ◽  
Faraday Effects

The magneto-optical effects play a prominent role in probing the exotic magnetism in 2D materials. Here, we present that the magneto-optical Kerr and Faraday effects in carrier-doped nitrogen–graphene crystals can be effectively mediated by electric, magnetic, and strain fields. Our results indicate that nitrogen–graphene crystals provide a novel 2D material platform for nano-spintronics and magneto-optical devices.

scholarly journals 2D material liquid crystals for optoelectronics and photonics

2017 ◽  
Vol 5 (43) ◽  
pp. 11185-11195 ◽  
Author(s):  
B. T. Hogan ◽  
E. Kovalska ◽  
M. F. Craciun ◽  
A. Baldycheva
Keyword(s):  
Liquid Crystals ◽  
Materials Science ◽  
2D Materials ◽  
2D Material

The merging of the materials science paradigms of liquid crystals and 2D materials promises superb new opportunities for the advancement of the fields of optoelectronics and photonics. In this review, we summarise the development and applications of 2D material liquid crystals for optoelectronics and photonics.

scholarly journals Ideal optical contrast for 2D material observation using bi-layer antireflection absorbing substrates

Nanoscale ◽  
2019 ◽  
Vol 11 (13) ◽  
pp. 6129-6135 ◽  
Author(s):  
Kevin Jaouen ◽  
Renaud Cornut ◽  
Dominique Ausserré ◽  
Stéphane Campidelli ◽  
Vincent Derycke
Keyword(s):  
Double Layer ◽  
Film Growth ◽  
2D Materials ◽  
High Sensitivity ◽  
Optical Contrast ◽  
2D Material ◽  
Molecular Film

Optimized double-layer antireflection substrates allow observation of 2D materials with greatly enhanced contrast and molecular film growth with ultra-high sensitivity.

2D material broadband photodetectors

Nanoscale ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 454-476 ◽  
Author(s):  
Jiandong Yao ◽  
Guowei Yang
Keyword(s):  
2D Materials ◽  
Hybrid Structures ◽  
2D Material ◽  
Application Prospects ◽  
High Application

2D materials and their hybrid structures have high application prospects in broadband photodetection, making them promising complements to traditional schemes.

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