Graphene Growth on SiC and Metal Surfaces by Solid Source Carbon Deposition

AbstractGraphene has been grown by direct deposition of carbon from solid sources on both SiC and Ta films on SiC in an MBE environment. Carbon fluxes were obtained from thermally evaporated C60 and from a heated graphite filament. The graphene films were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy. Graphene films on Si-face SiC grown by carbon source MBE (CSMBE) were compared with graphene grown by the standard epitaxial graphene process using SiC thermal decomposition. CSMBE on SiC was found to grow at lower temperatures (1200°C) and to have fewer pits and a more uniform surface. Uniform graphene films were found to grow on Ta films after exposure to both carbon sources at 1200°C but Raman measurements showed no signs of graphene on films exposed to the same temperature without a carbon flux.

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Graphene growth on SiC and other substrates using carbon sources

MRS Proceedings ◽

10.1557/opl.2011.638 ◽

2011 ◽

Vol 1284 ◽

Author(s):

W. C. Mitchel ◽

J. H. Park ◽

Howard E. Smith ◽

L. Grazulis ◽

S. Mou ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Carbon Flux ◽

Carbon Sources ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Graphene Films ◽

Additional Control ◽

P Type ◽

Type Conduction

ABSTRACTDirect deposition of graphene from carbon sources on foreign substrates without the use of metal catalysts is shown to be an effective process with several advantages over other growth techniques. Carbon source molecular beam epitaxy (CMBE) in particular provides an additional control parameter in carbon flux and enables growth on substrates other than SiC, including oxidized Si and sapphire. CMBE using thermally evaporated C60 and a heated graphite filament on SiC is reported here. The graphene films were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy and Hall effect. Graphene films on Si-face SiC grown using the C60 source have Bernal-like stacking and n-type conduction while those grown using the graphite filament have turbostratic stacking and p-type conduction. The sheet concentration for both n- and p-type doping is linearly dependent on film thickness.

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Comparison of Epitaxial Graphene on Si-face and C-face 6H-SiC

MRS Proceedings ◽

10.1557/opl.2011.643 ◽

2011 ◽

Vol 1284 ◽

Author(s):

Shin Mou ◽

J. J. Boeckl ◽

L. Grazulis ◽

B. Claflin ◽

Weijie Lu ◽

...

Keyword(s):

Thermal Decomposition ◽

Raman Spectroscopy ◽

High Vacuum ◽

Hall Effect Measurement ◽

Radiative Heating ◽

Furnace Chamber ◽

Vacuum Furnace ◽

Force Microscopy ◽

Atomic Force ◽

Graphene Films

ABSTRACTWe present atomic force microscopy (AFM), Hall-effect measurement, and Raman spectroscopy results from graphene films on 6H-SiC (0001) and (000-1) faces (Si-face and C-face, respectively) produced by radiative heating in a high vacuum furnace chamber through thermal decomposition. We observe that the formation of graphene on the two faces of SiC is different in terms of the surface morphology, graphene thickness, Hall mobility, and Raman spectra. In general, graphene films on the SiC C-face are thicker with higher mobilities than those grown on the Si-face.

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Fabrication of Uniformly Growing Graphene Films via the Dip-Coating Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.320.185 ◽

2013 ◽

Vol 320 ◽

pp. 185-189

Author(s):

Juan Yang ◽

Hong Bo Sun ◽

Dan Li

Keyword(s):

Sheet Resistance ◽

Photoelectron Spectroscopy ◽

Dip Coating ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Graphene Films ◽

Coating Method ◽

Dip Coating Method ◽

Dip Coating Technique

The graphene (GE) films were fabricated in this paper through the deposition of graphene oxide (GO) sheets onto the quartz slide by means of dip-coating technique, followed by thermal annealing. The growth process and transmittance of the film were monitored by ultraviolet and visible spectrophotometer (UV-Vis), the surface morphology and structure were investigated by Atomic force microscopy (AFM), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Raman. The sheet resistance of the film was also tested and results showed that the sheet resistance is about 60 kΩ-1and the transmittance is as high as 81 % (at 550 nm).

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Formation of the YBa2Cu2NbOy phase in thin films

Journal of Materials Research ◽

10.1557/jmr.2009.0009 ◽

2009 ◽

Vol 24 (1) ◽

pp. 212-216

Author(s):

Srinivas Sathiraju ◽

Paul N. Barnes ◽

Robert A. Wheeler

Keyword(s):

Thin Films ◽

Raman Spectroscopy ◽

Photoelectron Spectroscopy ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Micro Raman Spectroscopy ◽

Atomic Force ◽

Transmission Electron ◽

New Phase

We report the systematic substitution of Nb at the Cu1 site of YBa2Cu3Oy in thin films to form a new phase of YBa2Cu2NbO8. These films were deposited on SrTiO3(100) crystals using pulsed laser deposition and deposited at an optimal temperature of 850 °C. Films were characterized using x-ray diffraction (XRD), atomic force microscopy, x-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, and transmission electron microscopy. XRD of these films indicate c-axis oriented YBa2Cu2NbOy formation. XPS and micro-Raman spectroscopy analysis suggests Cu exists in the +2 state.

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Polystyrene as Graphene Film and 3D Graphene Sponge Precursor

10.20944/preprints201811.0437.v1 ◽

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.

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Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

MRS Proceedings ◽

10.1557/proc-780-y5.5 ◽

2003 ◽

Vol 780 ◽

Author(s):

C. Essary ◽

V. Craciun ◽

J. M. Howard ◽

R. K. Singh

Keyword(s):

Uv Radiation ◽

Photoelectron Spectroscopy ◽

Grazing Angle ◽

X Ray Diffraction ◽

Metal Thin Films ◽

X Ray ◽

Force Microscopy ◽

Si Substrates ◽

Atomic Force ◽

Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

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Curcumin delivery by modified biosourced carbon-based nanoparticles

Nanomedicine ◽

10.2217/nnm-2021-0225 ◽

2022 ◽

Author(s):

Hossein Danafar ◽

Marziyeh Salehiabar ◽

Murat Barsbay ◽

Hossein Rahimi ◽

Mohammadreza Ghaffarlou ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Free System ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Good Biocompatibility ◽

Drug Free ◽

Mcf 7 ◽

Carbon Based

Aim: To prepare a novel hybrid system for the controlled release and delivery of curcumin (CUR). Methods: A method for the ultrasound-assisted fabrication of protein-modified nanosized graphene oxide-like carbon-based nanoparticles (CBNPs) was developed. After being modified with bovine serum albumin (BSA), CUR was loaded onto the synthesized hybrid (labeled CBNPs@BSA–CUR). The structure and properties of the synthesized nanoparticles were elucidated using transmission electron microscopy (TEM), atomic force microscopy (AFM), ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS) methods. Results: CBNPs@BSA–CUR showed pH sensitivity and were calculated as controlled CUR release behavior. The drug-free system exhibited good biocompatibility and was nontoxic. However, CBNPs@BSA–CUR showed acceptable antiproliferative ability against MCF-7 breast cancer cells. Conclusion: CBNPs@BSA–CUR could be considered a highly promising nontoxic nanocarrier for the delivery of CUR with good biosafety.

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Effect of Surface Chemistry on Ruthenium Wet Etching

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.314.302 ◽

2021 ◽

Vol 314 ◽

pp. 302-306

Author(s):

Quoc Toan Le ◽

E. Kesters ◽

M. Doms ◽

Efrain Altamirano Sánchez

Keyword(s):

Surface Roughness ◽

Photoelectron Spectroscopy ◽

Etching Rate ◽

Wet Etching ◽

X Ray ◽

Force Microscopy ◽

Metal Free ◽

Atomic Force ◽

Different Types ◽

Effect Of Surface

Different types of ALD Ru films, including as-deposited, annealed Ru, without and with a subsequent CMP step, were used for wet etching study. With respect to the as-deposited Ru, the etching rate of the annealed Ru film in metal-free chemical mixtures (pH = 7-9) was found to decrease substantially. X-ray photoelectron spectroscopy characterization indicated that this behavior could be explained by the presence of the formation of RuOx (x = 2,3) caused by the anneal. A short CMP step applied to the annealed Ru wafer removed the surface RuOx, at least partially, resulting in a significant increase of the etching rate. The change in surface roughness was quantified using atomic force microscopy.

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