Synthesis of 2D Heterostructures: MOS2/GO and MOS2/Graphene via Microdrop and CVD Deposition

2022 ◽  
Author(s):  
Diogo José Horst ◽  
Charles Adriano Duvoisin ◽  
Rogério De Almeida Vieira ◽  
Jesús Alejandro Arizpe ◽  
Esther Alejandra Huitrón Segovia ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Structural Information ◽  
Electronic Devices ◽  
Chemical Vapor ◽  
Electronic Coupling ◽  
Graphene Monolayer ◽  
Two Dimensional ◽  
Kelvin Probe ◽  
X Ray ◽  
Force Microscopy

The main objective of this work was to study the synthesis and characteristics of two-dimensional heterostructures (2D/2D) using pure molybdenum disulfide (MoS[Formula: see text] and doped with phosphorus at 5% and 15% combined with graphene oxide (GO) and graphene monolayer. These were deposited on silicon and copper substrates using two different deposition methods: Microdrop casting and chemical vapor deposition. Chemical and structural information of the samples were characterized by Raman spectroscopy, Energy Dispersion X-ray Spectroscopy (EDS), Scanning Electron Microscopy (SEM) and Kelvin Probe Force Microscopy (KPFM). The results prove the synergy between the materials resulting in electronic coupling, making this system potential for applications in electronic devices such as sensors, resistors and capacitors.

Crystalline Orientation of PbTiO3 Nanorods Grown by MOCVD Using ZnO Nanorods as a Template

2011 ◽  
Vol 1292 ◽  
Author(s):  
Hironori Fujisawa ◽  
Masaru Shimizu ◽  
Ryohei Kuri ◽  
Seiji Nakashima ◽  
Yasutoshi Kotaka ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Zno Nanorods ◽  
Chemical Vapor ◽  
Piezoresponse Force Microscopy ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Crystalline Orientation ◽  
X Ray ◽  
Force Microscopy

ABSTRACTPbTiO3-covered ZnO nanorods were grown on Al2O3$\left({11\bar 20} \right)$ by metalorganic chemical vapor deposition (MOCVD), and their crystalline orientation was investigated by x-ray diffraction (XRD). Structural analysis by scanning electron microscopy and XRD revealed that the hexagonal ZnO nanorods had $\left\{ {10\bar 10} \right\}$-side facets. XRD analysis of PbTiO3 thin films on ZnO$\left({10\bar 10} \right)$/Al2O3$\left({10\bar 10} \right)$revealed that PbTiO3 was epitaxially grown on ZnO$\left({10\bar 10} \right)$, showing 6 variants of crystallites with the c-axis tilted either 27o or 69o from the surface normal to the ZnO$\left({10\bar 10} \right)$ plane. Effective piezoelectric coefficients calculated for the 27o and 69o-crystallites using piezoresponse force microscopy confirm that deformation of nanorods and nanotubes contributed to the large electrically-induced strain along the radial direction.

Low Temperature Chemical Vapor Deposition of 3C-SiC on Si Substrates

2005 ◽  
Vol 483-485 ◽  
pp. 201-204 ◽  
Author(s):  
Christian Förster ◽  
Volker Cimalla ◽  
Oliver Ambacher ◽  
Jörg Pezoldt
Keyword(s):  
Gas Phase ◽  
Vapor Deposition ◽  
Growth Process ◽  
Chemical Vapor ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force

In the present work an UHVCVD method was developed which allows the epitaxial growth of 3C-SiC on Si substrates at temperatures below 1000°C. The developed method enable the growth of low stress or nearly stress free single crystalline 3C-SiC layers on Si. The influence of hydrogen on the growth process are be discussed. The structural properties of the 3C-SiC(100) layers were studied with reflection high-energy diffraction, atomic force microscopy, X-ray diffraction and the layer thickness were measured by reflectometry as well as visible ellipsometry. The tensile strain reduction at optimized growth temperature, Si/C ratio in the gas phase and deposition rate are demonstrated by the observation of freestanding SiC cantilevers.

scholarly journals Demonstration of the key substrate-dependent charge transfer mechanisms between monolayer MoS2 and molecular dopants

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Soohyung Park ◽  
Thorsten Schultz ◽  
Xiaomin Xu ◽  
Berthold Wegner ◽  
Areej Aljarb ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Photoelectron Spectroscopy ◽  
Electronic Devices ◽  
Electronic Coupling ◽  
Transition Metal Dichalcogenide ◽  
Two Dimensional ◽  
Monolayer Mos2 ◽  
X Ray ◽  
Molecular Electron ◽  
Transfer Mechanisms

Abstract Tuning the Fermi level (EF) in two-dimensional transition metal dichalcogenide (TMDC) semiconductors is crucial for optimizing their application in (opto-)electronic devices. Doping by molecular electron acceptors and donors has been suggested as a promising method to achieve EF-adjustment. Here, we demonstrate that the charge transfer (CT) mechanism between TMDC and molecular dopant depends critically on the electrical nature of the substrate as well as its electronic coupling with the TMDC. Using angle-resolved ultraviolet and X-ray photoelectron spectroscopy, we reveal three fundamentally different, substrate-dependent CT mechanisms between the molecular electron acceptor 1,3,4,5,7,8-hexafluoro-tetracyano-naphthoquinodimethane (F6TCNNQ) and a MoS2 monolayer. Our results demonstrate that any substrate that acts as charge reservoir for dopant molecules can prohibit factual doping of a TMDC monolayer. On the other hand, the three different CT mechanisms can be exploited for the design of advanced heterostructures, exhibiting tailored electronic properties in (opto-)electronic devices based on two-dimensional semiconductors.

Growth and Surface Morphologies of 6H SiC Bulk and Epitaxial Crystals

2006 ◽  
Vol 527-529 ◽  
pp. 67-70 ◽  
Author(s):  
Govindhan Dhanaraj ◽  
Yi Chen ◽  
Michael Dudley ◽  
Hui Zhang
Keyword(s):  
Vapor Deposition ◽  
Chemical Vapor ◽  
Structural Quality ◽  
Epitaxial Layers ◽  
Bulk Crystals ◽  
Hydrogen Etching ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Surface Morphologies

Bulk crystals and epitaxial layers of 6H SiC have been grown and their surface morphologies have been investigated. Seeded sublimation has been employed to obtain bulk 6H SiC crystals whereas a silicon tetrachloride-propane based chemical vapor deposition (CVD) was used for growing epitaxial layers. The hot-zones were designed using numerical simulation. Growth rates up to 200 μm/hr could be achieved in the CVD process. A new growth-assisted hydrogen etching was developed to reveal the distribution of the micropipes present in the substrate. Morphological features were studied using Nomarski, atomic force microscopy (AFM), and scanning electron microscopy (SEM), and the structural quality was evaluated using synchrotron X-ray topography.

Growth of crack-free GaN on AlN quantum dots on Si(111)substrates by MOCVD

2003 ◽  
Vol 798 ◽  
Author(s):  
W. H. Sun ◽  
J. L. Chen ◽  
L. S. Wang ◽  
S. J. Chua
Keyword(s):  
Quantum Dots ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Pressure Chemical ◽  
Aln Buffer

AlN self-assembled quantum dots (QDs) with high density of ∼ 4.4 × 1010/cm2 on Si(111) substrates have been grown by low-pressure chemical vapor deposition under a very low V/III ratio of 350. We found that using AlN-QD/AlN buffer two-inch GaN epilayers without cracks were grown, indicating the underlying quantum dots play a crucial role in relaxing the stain of GaN epilayer. The quality and morphology were investigated by atom force microscopy, transmission electron microscopy, X-ray diffraction and optical microscope.

scholarly journals Tantalum diffusion barrier grown by inorganic plasma-promoted chemical vapor deposition: Performance in copper metallization

2000 ◽  
Vol 15 (12) ◽  
pp. 2800-2810 ◽  
Author(s):  
Alain E. Kaloyeros ◽  
Xiomeng Chen ◽  
Sarah Lane ◽  
Harry L. Frisch ◽  
Barry Arkles
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Rutherford Backscattering Spectrometry ◽  
Chemical Vapor ◽  
Diffusion Barriers ◽  
Copper Metallization ◽  
X Ray ◽  
Force Microscopy ◽  
Tantalum Films

As-deposited and annealed tantalum films, grown by plasma-promoted chemical vapor deposition (PPCVD) using pentabromotantalum and hydrogen as coreactants, were evaluated as diffusion barriers in copper metallization. Stacks consisting of 500-nm-thick sputtered Cu/55-nm-thick untreated PPCVD Ta/Si were annealed in argon in the range 450 to 650 °C, in 50 °C intervals, along with sputtered Cu/preannealed PPCVD Ta/Si and sputtered Cu/sputtered Ta/Si stacks of identical thickness. Pre- and postannealed stacks were characterized by x-ray photoelectron spectroscopy, Auger electron spectroscopy, Rutherford backscattering spectrometry, hydrogen profiling, x-ray diffraction, atomic force microscopy, sheet resistance measurements, and Secco chemical treatment and etch-pit observation by scanning electron microscopy. The sputtered and preannealed PPCVD Ta films acted as viable diffusion barriers up to 550 °C, while the as-deposited PPCVD Ta films failed above 500 °C. In all cases, breakdown occurred through the migration of Cu into Si, rather than an interfacial reaction between Ta and Si, in agreement with previously reported results for sputtered Ta films. The accelerated barrier failure for as-deposited PPCVD Ta might have been caused by the presence of approximately 20 at.% hydrogen in the as-deposited PPCVD Ta, an observation which was supported by the enhanced performance of the same PPCVD Ta films after annealing-induced hydrogen removal.

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