Surface Corrugation and Stacking Misorientation in Multilayers of Graphene on Nickel

2011 ◽  
Vol 178-179 ◽  
pp. 125-129 ◽  
Author(s):  
Vito Raineri ◽  
Corrado Bongiorno ◽  
Salvatore di Franco ◽  
Raffaella Lo Nigro ◽  
Emanuele Rimini ◽  
...  
Keyword(s):  
Film Formation ◽  
Graphene Film ◽  
Thermal Processes ◽  
Grown Film ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Films ◽  
Transmission Electron ◽  
Thin Polycrystalline

Graphene films were grown on thin polycrystalline Ni using a buried amorphous carbon (a-C) layer as C source. Rapid thermal processes (RTP) at temperatures from 600 to 800°C were used to promote C diffusion into Ni and its subsequent segregation on Ni surface, during the sample cool down. RTP at 800°C was the optimal condition for graphene film formation. Micro-Raman spectroscopy showed that the grown film is mostly composed by multilayers of graphene. Atomic force microscopy showed that the film presents peculiar corrugations (wrinkles), isotropically oriented and with heights ranging from from ~1 to ~15 nm. Selected area diffraction by transmission electron microscopy on the MLG membranes shows a rotational disorder between the stacked graphene layers.

scholarly journals Growth of Ordered Graphene Ribbons by Sublimation Epitaxy

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 449
Author(s):  
Shuxian Cai ◽  
Xingfang Liu ◽  
Xin Zheng ◽  
Zhonghua Liu
Keyword(s):  
Substrate Surface ◽  
Graphene Film ◽  
Graphene Ribbon ◽  
High Quality ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Layer Graphene ◽  
Micro Raman Spectroscopy ◽  
Atomic Force ◽  
Few Layer Graphene

Ordered graphene ribbons were grown on the surface of 4° off-axis 4H-SiC wafers by sublimation epitaxy, and characterized by using scanning electron microscopy (SEM), atomic force microscopy (AFM) and micro-Raman spectroscopy (μ-Raman). SEM showed that there were gray and dark ribbons on the substrate surface, and AFM further revealed that these ordered graphene ribbons had clear stepped morphologies due to surface step-bunching. It was shown by μ-Raman that the numbers of graphene layers of these two types of regions were different. The gray region was composed of mono- or bilayer ordered graphene ribbon, while the dark region was of tri- or few-layer ribbon. Meanwhile, ribbons were all homogeneous and had a width up to 40 μm and a length up to 1000 μm, without micro defects such as grain boundaries, ridges, or mono- and few-layer graphene mixtures. The results of this study are useful for optimized growth of high-quality graphene film on silicon carbide crystal.

Temperature Dependent Structural Evolution of Graphene Layers on 4H-SiC(0001)

2011 ◽  
Vol 679-680 ◽  
pp. 797-800 ◽  
Author(s):  
Sushant Sonde ◽  
Carmelo Vecchio ◽  
Filippo Giannazzo ◽  
Corrado Bongiorno ◽  
Salvatore di Franco ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Evolution ◽  
Morphological Transformation ◽  
Temperature Dependent ◽  
Microscopy Imaging ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Mode Atomic Force Microscopy

In this study we examined the structural evolution of graphene grown on 8° off-axis 4H-SiC(0001) substrates at temperatures from 1600°C to 1700°C in Ar ambient. Morphological transformation of SiC substrate after annealing was examined by Tapping Mode Atomic Force Microscopy. Moreover, by etching-out graphene layers from graphitized SiC substrates in selective trenches we determined the number of graphene layers. Numbers of graphene layers were then independently confirmed by Transmission Electron Microscopy imaging.

A Model for the Films Formation of Nb–Si–N Ternary Compound Deposited

2012 ◽  
Vol 476-478 ◽  
pp. 475-479 ◽  
Author(s):  
Yong Jun Jiang
Keyword(s):  
Film Formation ◽  
Composite Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanoscale Structures ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Step Model ◽  
Si Content

By means of the reactive magnetron sputtering method, a series of Nb–Si–N composite films with different Si contents were deposited in an Ar, N2 and SiH4 mixture atmosphere. These films’ chemical composition, phase formation, microstructure and mechanical properties were characterized by the energy dispersive spectroscopy, X-ray diffraction, transmission electron microcopy, atomic force microscopy and nanoindentation. In the Nb–Si–N films, 3 distinct concentration regions have been observed depending on the Si content. Based on the three concentration regions, a three-step model is proposed for the film formation of the Nb–Si–N thin films. This model correlates nanoscale structures with macroscopic properties of the films.

Microscopy of latex film formation

1994 ◽  
Vol 52 ◽  
pp. 1042-1043
Author(s):  
Yaqiang Ming
Keyword(s):  
Electron Microscopy ◽  
Film Formation ◽  
Freeze Fracture ◽  
Colloidal Dispersion ◽  
Latex Film ◽  
Force Microscopy ◽  
Paper Coatings ◽  
Atomic Force ◽  
Transmission Electron ◽  
Cryogenic Scanning Electron Microscopy

Latex here denotes a stable colloidal dispersion of polymer in solvent. The solvent usually is water. Large tonnages of latices are used in paper coatings, paints, and growing numbers of other waterbased coatings. All these applications require the latices to be film-forming, at least to a degree. Despite past investigations, the mechanisms of film formation are not well understood and are now being studied intensively in several places.Our goal is to understand how a suspension of latex particles in water or other solvent becomes a continuous film, one monolayer or multiple layers deep. Several techniques have been employed: transmission electron microscopy ( TEM ) including replication, freeze-fracture, and microtome sample preparations, small angle neutron scattering ( SANS ); cryogenic scanning electron microscopy ( Cryo-SEM ), and atomic force microscopy ( AFM ). TEM is tedious and requires small thin samples; SANS is expensive, time consuming, and difficult to interpret; AFM is easy to use, but images must be interpreted with caution because artifacts can prevail.

Preparation of a P(FcA-co-ANI)/graphene composite for application in supercapacitors

2016 ◽  
Vol 29 (5) ◽  
pp. 524-532 ◽  
Author(s):  
Yunlong Li ◽  
Yuying Zheng
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Impedance ◽  
Proton Nuclear Magnetic Resonance ◽  
Diffusion Resistance ◽  
X Ray Diffraction ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Surface Morphologies

A conducting copolymer of 1,1′-ferrocenediacyl anilide and aniline (P(FcA-co-ANI)) was synthesized, which had a conjugated structure and ferrocene moieties in the main chain. The monomer and copolymer were characterized using proton nuclear magnetic resonance and Fourier-transform infrared (FTIR) spectroscopies. A P(FcA-co-ANI)/reduced graphene oxide (rGO) composite was synthesized by oxidation polymerization, using rGO as a substrate. The characteristic peaks of P(FcA-co-ANI) and rGO were observed in the FTIR spectrum of P(FcA-co-ANI)/rGO. The X-ray diffraction pattern of P(FcA-co-ANI)/rGO exhibited similar peaks to the pattern of P(FcA-co-ANI), except for the absence of the weak broad peak at 9.0° owing to rGO. The surface morphologies of the materials were characterized by atomic force microscopy, transmission electron microscopy and scanning electron microscopy. The interlayer distances of rGO and P(FcA-co-ANI)/rGO were 0.96 and 1.38 nm, respectively. The morphology of the copolymer was spherical, and it contained island structures covering the surface of the graphene layers. The electrochemical properties of the composite were measured by cyclic voltammetry, galvanostatic charge–discharge measurements and electrochemical impedance spectroscopy. The maximum specific capacitance of the composite was 722.5 F/g at 0.5 A/g. The diffusion resistance was very small, and the composites durability was sufficient for subjecting to prolonged oxidation and reduction.

Structural Characterization of Graphene Grown by Thermal Decomposition of Off-Axis 4H-SiC (0001)

2012 ◽  
Vol 711 ◽  
pp. 141-148 ◽  
Author(s):  
Filippo Giannazzo ◽  
Martin Rambach ◽  
Wielfried Lerch ◽  
Corrado Bongiorno ◽  
Salvatore di Franco ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Cross Section ◽  
Structural Characterization ◽  
Plan View ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron

We present a nanoscale morphological and structural characterization of few layers of graphene grown by thermal decomposition of off-axis 4H-SiC (0001). A comparison between transmission electron microscopy (TEM) in cross-section and in plan view allows to fully exploit the potentialities of TEM. Such a comparison was used to get information on the number of graphene layers as well as on the rotational order between the layers and with respect to the substrate. Some peculiar structures observed by TEM (wrinkles) could only be systematically measured by atomic force microscopy (AFM). In particular, the density and the height of the wrinkles in the few layers of graphene was investigated.

scholarly journals Polystyrene as Graphene Film and 3D Graphene Sponge Precursor

2018 ◽  
Author(s):  
Alejandra Rendón-Patiño ◽  
Jinan Niu ◽  
Antonio Doménech-Carbó ◽  
Hermenegildo García ◽  
Ana Primo
Keyword(s):  
Thin Film ◽  
Photoelectron Spectroscopy ◽  
Graphene Film ◽  
Visible Absorption ◽  
X Ray ◽  
3D Graphene ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Films ◽  
Graphene Sponge

Polystyrene as a thin film on arbitrary substrates or pellets form defective graphene films or powders that can be dispersed in water and organic solvents. The materials were characterized by visible absorption, Raman and X-ray photoelectron spectroscopy, electron and atomic force microscopy and electrochemistry. Raman spectra of these materials show the presence of the expected 2D, G and D peaks at 2750, 1590 and 1350 cm-1, respectively. The relative intensity of the G vs. the D peak is taken as a quantitative indicator of the density of defects in the G layer.

Scanning tunneling microscopy and atomic force microscopy: New tools for biology

1989 ◽  
Vol 47 ◽  
pp. 778-779
Author(s):  
CE Bracker ◽  
P. K. Hansma
Keyword(s):  
Physical Property ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Small Scale ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
New Family ◽  
Small Probe ◽  
Atomic Force ◽  
Transmission Electron

A new family of scanning probe microscopes has emerged that is opening new horizons for investigating the fine structure of matter. The earliest and best known of these instruments is the scanning tunneling microscope (STM). First published in 1982, the STM earned the 1986 Nobel Prize in Physics for two of its inventors, G. Binnig and H. Rohrer. They shared the prize with E. Ruska for his work that had led to the development of the transmission electron microscope half a century earlier. It seems appropriate that the award embodied this particular blend of the old and the new because it demonstrated to the world a long overdue respect for the enormous contributions electron microscopy has made to the understanding of matter, and at the same time it signalled the dawn of a new age in microscopy. What we are seeing is a revolution in microscopy and a redefinition of the concept of a microscope.Several kinds of scanning probe microscopes now exist, and the number is increasing. What they share in common is a small probe that is scanned over the surface of a specimen and measures a physical property on a very small scale, at or near the surface. Scanning probes can measure temperature, magnetic fields, tunneling currents, voltage, force, and ion currents, among others.

The Electrical Characterization and Physical Failure Analysis for Transistor Gate Leakage

2006 ◽  
Author(s):  
Tsung-Te Li ◽  
Chao-Chi Wu ◽  
Jung-Hsiang Chuang ◽  
Jon C. Lee
Keyword(s):  
Failure Analysis ◽  
Electrical Characterization ◽  
Physical Analysis ◽  
Gate Leakage ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Voltage Stress ◽  
Leakage Site

Abstract This article describes the electrical and physical analysis of gate leakage in nanometer transistors using conducting atomic force microscopy (C-AFM), nano-probing, transmission electron microscopy (TEM), and chemical decoration on simulated overstressed devices. A failure analysis case study involving a soft single bit failure is detailed. Following the nano-probing analysis, TEM cross sectioning of this failing device was performed. A voltage bias was applied to exaggerate the gate leakage site. Following this deliberate voltage overstress, a solution of boiling 10%wt KOH was used to etch decorate the gate leakage site followed by SEM inspection. Different transistor leakage behaviors can be identified with nano-probing measurements and then compared with simulation data for increased confidence in the failure analysis result. Nano-probing can be used to apply voltage stress on a transistor or a leakage path to worsen the weak point and then observe the leakage site easier.

scholarly journals Vertical monolithic integration of wide- and narrow-bandgap semiconductor nanostructures on graphene films

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Youngbin Tchoe ◽  
Janghyun Jo ◽  
HoSung Kim ◽  
Heehun Kim ◽  
Hyeonjun Baek ◽  
...  
Keyword(s):  
Graphene Film ◽  
Monolithic Integration ◽  
Hybrid Nanostructures ◽  
Dual Wavelength ◽  
Multilayer Graphene ◽  
Graphene Films ◽  
Transmission Electron ◽  
Zno Nanotubes ◽  
Metal Organic ◽  
Hybrid Configuration

AbstractWe report monolithic integration of indium arsenide (InAs) nanorods and zinc oxide (ZnO) nanotubes using a multilayer graphene film as a suspended substrate, and the fabrication of dual-wavelength photodetectors with the hybrid configuration of these materials. For the hybrid nanostructures, ZnO nanotubes and InAs nanorods were grown vertically on the top and bottom surfaces of the graphene films by metal-organic vapor-phase epitaxy and molecular beam epitaxy, respectively. The structural, optical, and electrical characteristics of the hybrid nanostructures were investigated using transmission electron microscopy, spectral photoresponse analysis, and current–voltage measurements. Furthermore, the hybrid nanostructures were used to fabricate dual-wavelength photodetectors sensitive to both ultraviolet and mid-infrared wavelengths.

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