Epitaxial graphene on SiC($0 0 0\bar {1}$): functional electrical microscopy studies and effect of atmosphere

Kazakova, Olga; Burnett, Tim L.; Patten, J.W.; Yang, Liu; Yakimova, Rositsa

doi:10.1088/0957-4484/24/21/215702

Cited by 25 publications

(25 citation statements)

References 51 publications

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“…The diodes fabricated on n-Si substrates exhibit clear rectifying behavior, while the devices fabricated on p-Si substrate show non-rectifying behavior. We attribute this to ambient p-type doping of the graphene caused by a combination of air humidity and molecules [12], [13]. Hence, all further experiments in this work focus on the graphene -nSi diodes.…”

Section: Resultsmentioning

confidence: 97%

Spectral sensitivity of a graphene/silicon pn-junction photodetector

Riazimehr

Schneider

Yim

et al. 2015

EUROSOI-ULIS 2015: 2015 Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon

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We investigate the optical properties of graphenesilicon Schottky barrier diodes composed of chemical vapor deposited (CVD) graphene on n-and p-type silicon (Si) substrates. The diodes fabricated on n-Si substrate exhibit better rectifying behavior compared to p-Si devices in the dark. An ultra-broadband spectral response is achieved for n-Si diodes. The results are compared with the spectral response of a molybdenum disulfide (MoS 2 ) -p-type silicon photodiode.

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Section: Resultsmentioning

confidence: 97%

Spectral sensitivity of a graphene/silicon pn-junction photodetector

Riazimehr

Schneider

Yim

et al. 2015

EUROSOI-ULIS 2015: 2015 Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon

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“…Upon the following cooling down to RT2, the initial roughness of the 2 LG is restored as water is re-absorbed [9]. As the atmospheric water molecules adsorb on the sample surface [67,70,79], they affect the overall surface potential, V CPD , of the graphene. In the following set of experiments, we investigate modification of the surface potential of graphene as a result of the temperature change and corresponding transformation of the water layer.…”

Section: Case Of Epitaxial Graphene On Si-face Sicmentioning

confidence: 99%

Epitaxial Graphene and Graphene–Based Devices Studied by Electrical Scanning Probe Microscopy

2013

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Abstract:We present local electrical characterization of epitaxial graphene grown on both Si-and C-faces of 4H-SiC using Electrostatic Force Microscopy and Kelvin Probe Force Microscopy in ambient conditions and at elevated temperatures. These techniques provide a straightforward identification of graphene domains with various thicknesses on the substrate where topographical determination is hindered by adsorbates and SiC terraces. We also use Electrostatic Force Spectroscopy which allows quantitative surface potential measurements with high spatial resolution. Using these techniques, we study evolution of a layer of atmospheric water as a function of temperature, which is accompanied by a significant change of the absolute surface potential difference. We show that the nanoscale wettability of the material is strongly dependent on the number of graphene layers, where hydrophobicity increases with graphene thickness. We also use micron-sized graphene Hall bars with gold electrodes to calibrate work function of the electrically conductive probe and precisely and quantitatively define the work functions for single-and double-layer graphene.

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“…[11][12][13][14][15][16][17][18] A summary of reported WCA measurements of graphite and graphene materials [reduced graphene oxide (GO), epitaxial graphene (EG), and chemical vapor deposition (CVD) synthesized graphene] is presented in Table 1. 6,[8][9][10][11][12][13][14][15][16][17][19][20][21][22] In the majority of previous works, graphite is considered a hydrophobic material, with WCA values in the range of approximately 80-100° (e.g. 85-98°).…”

Section: Introductionmentioning

confidence: 99%

“…Mono-and multilayer EG on SiC 72.9 (single) 91.6 (multi) (20) Reduced GO on stainless steel 120 - (21) Reduced GO on quartz 66.5-69 - (22) a HOPG, highly ordered pyrolytic graphite; EG, epitaxial graphene; GO, reduced graphene oxide; CVD, chemical vapor deposition.…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic Investigation of the Wettability of Multilayer Graphene Using Highly Ordered Pyrolytic Graphite as a Model Material

Ashraf

Wang

et al. 2014

Langmuir

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We report the intrinsic water contact angle (WCA) of multilayer graphene, explore different methods of cleaning multilayer graphene, and evaluate the efficiency of those methods on the basis of spectroscopic analysis. Highly ordered pyrolytic graphite (HOPG) was used as a model material system to study the wettability of the multilayer graphene surface by WCA measurements. A WCA value of 45° ± 3° was measured for a clean HOPG surface, which can serve as the intrinsic WCA for multilayer graphene. A 1 min plasma treatment (100 W) decreased the WCA to 6°, owing to the creation of surface defects and functionalization by oxygen-containing groups. Molecular dynamics simulations of water droplets on the HOPG surface with or without the oxygen-containing defect sites confirmed the experimental results. Heat treatment at near atmospheric pressure and wet chemical cleaning methods using hydrofluoric acid and chloroform did not change the WCA significantly. Low-pressure, high-temperature annealing under argon and hydrogen reduced the WCA to 54°, close to the intrinsic WCA of HOPG. Raman spectroscopy and atomic force microscopy did not show any significant change for the HOPG surface after this treatment, confirming low-pressure, high-temperature annealing as an effective technique to clean multilayer graphene without damaging the surface. Time-of-flight secondary ion mass spectrometry indicated the existence of hydrocarbon species on the surface of the HOPG sample that was exposed to air for <5 min and the absence of these impurities in the bulk. X-ray photoelectron spectroscopy analyses of the sample surfaces after the different cleaning techniques were performed to correlate the WCA to the surface chemistry. X-ray photoelectron spectroscopy results revealed that the WCA value changed drastically, depending on the amounts of oxygen-containing and hydrocarbon-containing groups on the surface.

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Epitaxial graphene on SiC($0 0 0\bar {1}$): functional electrical microscopy studies and effect of atmosphere

Cited by 25 publications

References 51 publications

Spectral sensitivity of a graphene/silicon pn-junction photodetector

Spectral sensitivity of a graphene/silicon pn-junction photodetector

Epitaxial Graphene and Graphene–Based Devices Studied by Electrical Scanning Probe Microscopy

Spectroscopic Investigation of the Wettability of Multilayer Graphene Using Highly Ordered Pyrolytic Graphite as a Model Material

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