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“Real-space multiple scattering method for angle-resolved photoemission and valence-band photoelectron diffraction and its application to Cu(111)”. Krüger P, da Pieve F, Osterwalder J, Physical review : B : condensed matter and materials physics 83, 115437 (2011). http://doi.org/10.1103/PhysRevB.83.115437
Abstract: A computational method is presented for angle-resolved photoemission spectra (ARPES) and photoelectron diffraction (PED) in the ultraviolet regime. The one-step model is employed and both initial valence and final continuum states are calculated using the finite-cluster, real-space multiple scattering method. Thereby the approach is versatile and provides a natural link to core-level PED. The method is applied to the Cu(111) valence band and good agreement with experiment is found for both ARPES spectra and PED patterns. When the PED patterns are integrated over a filled band of a single-orbital symmetry, such as Cu-3d, we show, both numerically and analytically, that the exact theory with delocalized initial states can be replaced by the much simpler, core-level-type theory where the initial states are taken as localized.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 17
DOI: 10.1103/PhysRevB.83.115437
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“Rearrangement of the vortex lattice due to instabilities of vortex flow”. Vodolazov DY, Peeters FM, Physical review : B : condensed matter and materials physics 76, 014521 (2007). http://doi.org/10.1103/PhysRevB.76.014521
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 103
DOI: 10.1103/PhysRevB.76.014521
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“Reduced dimensionality in different forms of carbon”. Van Tendeloo G, Bernaerts D, Amelinckx S, Fullerenes and carbon based materials , 487 (1998)
Abstract: Several TEM techniques are used to characterise the local structure of low dimensional forms of carbon. HREM is particularly useful to describe the defect structure of thin films of diamond or fullerenes and C-60-C-70 nanoclusters. A columnar form of graphite is analysed, mainly by electron diffraction which allowed us to propose a growth mechanism. Diffraction contrast dark field microscopy, in combination with electron diffraction, allows a detailed characterisation of carbon nanotubes; e.g. the chirality distribution of tubes in ropes of single wall tubes is studied by selected area electron diffraction. (C) 1998 Elsevier Science Ltd. All rights reserved.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
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“Relation between structure, charge ordering and magnetotransport properties in Nd0.5Ca0.5Mn1-xCrxO3 manganites”. Schuddinck W, Van Tendeloo G, Barnabé, A, Hervieu M, Raveau B, Journal of magnetism and magnetic materials
T2 –, Symposium G Material Physics Issues and Applications of Magnetic Oxides, at the E-MRS Spring Meeting, JUN 01-04, 1999, Strasbourg, France 211, 105 (2000). http://doi.org/10.1016/S0304-8853(99)00720-9
Abstract: The relationships between incommensurability, charge ordering and magnetotransport properties in Nd0.5Ca0.5Mn1-xCrxO3 manganites have been studied by electron diffraction and lattice imaging versus temperature with 0.02 less than or equal to x less than or equal to 0.07. All compositions show an incommensurate superstructure over the whole temperature domain, despite the fact that they are ferromagnetic and conductive below 140 K, The q-vector (1/2 – delta)a* decreases with increasing temperature for all compositions x. For a given temperature q also decreases with x. Lattice images obtained at low temperature give a clear view of the characteristics of the incommensurate structure. They also provide a better understanding of the charge ordering process. The low-temperature form of the Cr-doped manganites is not a perfectly doubled cell [[2a(p)root 2 x 2a(p) x a(p)root 2]], but defects inducing a tripled cell occur pseudo-periodically. (C) 2000 Elsevier Science B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.63
Times cited: 16
DOI: 10.1016/S0304-8853(99)00720-9
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“Relative stability of negative and positive trions in model symmetric quantum wires”. Szafran B, Chwiej T, Peeters FM, Bednarek S, Adamowski J, Physical review : B : condensed matter and materials physics 71, 235305 (2005). http://doi.org/10.1103/PhysRevB.71.235305
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 25
DOI: 10.1103/PhysRevB.71.235305
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“Relaxor ferroelectricity and magnetoelectric coupling in ZnOCo nanocomposite thin films : beyond multiferroic composites”. Li DY, Zeng YJ, Batuk D, Pereira LMC, Ye ZZ, Fleischmann C, Menghini M, Nikitenko S, Hadermann J, Temst K, Vantomme A, Van Bael MJ, Locquet JP, Van Haesendonck C;, ACS applied materials and interfaces 6, 4737 (2014). http://doi.org/10.1021/am4053877
Abstract: ZnOCo nanocomposite thin films are synthesized by combination of pulsed laser deposition of ZnO and Co ion implantation. Both superparamagnetism and relaxor ferroelectricity as well as magnetoelectric coupling in the nanocomposites have been demonstrated. The unexpected relaxor ferroelectricity is believed to be the result of the local lattice distortion induced by the incorporation of the Co nanoparticles. Magnetoelectric coupling can be attributed to the interaction between the electric dipole moments and the magnetic moments, which are both induced by the incorporation of Co. The introduced ZnOCo nanocomposite thin films are different from conventional strain-mediated multiferroic composites.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 7.504
Times cited: 21
DOI: 10.1021/am4053877
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“Remote and spatially separated D- centers in quasi-two-dimensional semiconductor structures”. Marmorkos IK, Schweigert VA, Peeters FM, Physical review : B : condensed matter and materials physics 55, 5065 (1997)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 41
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“Remote Wigner polaron in a magnetic field”. Kato H, Peeters FM, Physical review : B : condensed matter and materials physics 59, 14342 (1999). http://doi.org/10.1103/PhysRevB.59.14342
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 3
DOI: 10.1103/PhysRevB.59.14342
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“Reply to Comment on “Frustrated octahedral tilting distortion in the incommensurately modulated Li3xNd2/3-xTiO3 perovskites””. Abakumov AM, Erni R, Tsirlin AA, Chemistry of materials 26, 1288 (2014). http://doi.org/10.1021/cm500005d
Keywords: Editorial; Electron microscopy for materials research (EMAT)
Impact Factor: 9.466
Times cited: 1
DOI: 10.1021/cm500005d
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“Reply to “Comment on 'Oscillator strength and sum rule for intersubband transitions in a superlattice'””. Peeters FM, Matulis A, Physical review : B : condensed matter and materials physics 51, 7932 (1995)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.736
Times cited: 1
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“Resistance effects due to magnetic guiding orbits”. Reijniers J, Peeters FM, Physical review : B : condensed matter and materials physics 63, 165317 (2001). http://doi.org/10.1103/PhysRevB.63.165317
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Engineering Management (ENM)
Impact Factor: 3.836
Times cited: 27
DOI: 10.1103/PhysRevB.63.165317
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“Revealing nanoscale structural TEM/HRTEM: application on ferroelectric ordering by PMN-PT relaxor ferroelectric”. Ghica C, Nistor L, Van Tendeloo G, Journal of optoelectronics and advanced materials 10, 2328 (2008)
Abstract: Nano-scale ordering may be revealed in transmission electron microscopy (TEM) by at least three techniques that will be presented in this work: selected area electron diffraction, conventional TEM and high-resolution TEM. Digital image processing is used to extract additional information from the high-resolution micrographs. The described methods are illustrated in a microstructural and compositional study of a 90%Pb(Mg1/3Nb2/3)O-3-10%PbTiO2 ceramic sample. High-resolution images reveal the presence of ordered compositional nano-domains, observable in two specific crystallographic orientations. Antiphase boundaries lying in the (111) planes separate them, while (100) and (111) facets separate the ordered domains from the disordered matrix.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 0.449
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“Revealing the innermost nanostructure of sputtered NiCrOx solar absorber cermets”. Gaouyat L, He Z, Colomer J-F, Lambin P, Mirabella F, Schryvers D, Deparis O, Solar energy materials and solar cells 122, 303 (2014). http://doi.org/10.1016/j.solmat.2013.10.009
Abstract: Conversion of solar energy into thermal energy helps reducing consumption of non-renewable energies. Cermets (ceramicmetal composites) are versatile materials suitable, amongst other applications, for solar selective absorbers. Although the presence of metallic Ni particles in the dielectric matrix is a prerequisite for efficient solar selective absorption in NiCrOx cermets, no clear evidence of such particles is reported so far. By combining comprehensive chemical and structural analyses, we reveal the presumed nanostructure which is at the origin of the remarkable optical properties of this cermet material. Using sputtered NiCrOx layers in a solar absorber multilayer stack on aluminium substrate allows us to achieve solar absorptance as high as α=96.1% while keeping thermal emissivity as low as ε=2.2%, both values being comparable to best values recorded so far. With the nanostructure of sputtered NiCrOx cermets eventually revealed, further optimization of solar absorbers can be anticipated and technological exploitation of cermet materials in other applications can be foreseen.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.784
Times cited: 12
DOI: 10.1016/j.solmat.2013.10.009
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“Review of phonon behaviour and microstructural development leading to martensitic transformations in NixAl100-x alloys”. Tanner LE, Shapiro SM, Schryvers D, Noda Y, Shape memory materials and phenomena: fundamental aspects and applications 246, 265 (1992)
Keywords: A3 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 4
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“Role of carbon and nitrogen in Fe2C and Fe2N from first-principles calculations”. Fang CM, van Huis MA, Jansen J, Zandbergen HW, Physical review : B : condensed matter and materials physics 84, 094102 (2011). http://doi.org/10.1103/PhysRevB.84.094102
Abstract: Although Fe2C and Fe2N are technologically important materials, the exact nature of the chemical bonding of C and N atoms and the related impact on the electronic properties are at present unclear. Here, results of first-principles electronic structure calculations for Fe2X (X = C, N) phases are presented. The electronic structure calculations show that the roles of N and C in iron nitrides and carbides are comparable, and that the X-X interactions have significant impact on electronic properties. Accurate analysis of the spatially resolved differences in electron densities reveals a subtle distinction between the chemical bonding and charge transfer of N and C ions.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 24
DOI: 10.1103/PhysRevB.84.094102
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“Role of PdOx and RuOy clusters in oxygen exchange between nanocrystalline tin dioxide and the gas phase”. Marikutsa AV, Rumyantseva MN, Frolov DD, Morozov IV, Boltalin AI, Fedorova AA, Petukhov IA, Yashina LV, Konstantinova EA, Sadovskaya EM, Abakumov AM, Zubavichus YV, Gaskov AM;, The journal of physical chemistry: C : nanomaterials and interfaces 117, 23858 (2013). http://doi.org/10.1021/jp408646k
Abstract: The effect of palladium- and ruthenium-based clusters on nanocrystalline tin dioxide interaction with oxygen was studied by temperature-programmed oxygen isotopic exchange with mass-spectrometry detection. The modification of aqueous sol-gel prepared SnO2 by palladium and, to a larger extent, by ruthenium, increases surface oxygen concentration on the materials. The revealed effects on oxygen exchange-lowering the threshold temperature, separation of surface oxygen contribution to the process, increase of heteroexchange rate and oxygen diffusion coefficient, decrease of activation energies of exchange and diffusion-were more intensive for Ru-modified SnO2 than in the case of SnO2/Pd. The superior promoting activity of ruthenium on tin dioxide interaction with oxygen was interpreted by favoring the dissociative O-2 adsorption and increasing the oxygen mobility, taking into account the structure and chemical composition of the modifier clusters.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 4.536
Times cited: 20
DOI: 10.1021/jp408646k
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“Round-robin investigation of silicon-oxide on silicon reference materials for ellipsometry”. Vanhellemont J, Maes HE, Schaekers M, Armigliato A, Cerva H, Cullis A, de Sande J, Dinges H, Hallais J, Nayar V, Pickering C, Stehlé, JL, Van Landuyt J, Walker C, Werner H, Salieri P;, Applied surface science
T2 –, SYMP ON DIAGNOSTIC TECHNIQUES FOR SEMICONDUCTOR MATERIALS ANALYSIS AND, FABRICATION PROCESS CONTROL, AT THE 1992 SPRING CONF OF THE EUROPEAN, MATERIALS RESEARCH SOC, JUN 02-05, 1992, STRASBOURG, FRANCE 63, 45 (1993). http://doi.org/10.1016/0169-4332(93)90062-G
Abstract: The main results and conclusions are presented of a round robin study of silicon oxide on silicon reference samples for ellipsometry. The oxide films with nominal thicknesses of 10, 50 and 120 nm are grown by thermal oxidation. The oxide film thicknesses have been determined by single wavelength ellipsometry (SWE), by spectroscopic ellipsometry (SE) and by cross-sectional conventional and high-resolution transmission electron microscopy (TEM and HREM) in different laboratories. The main conclusions are that special precautions have to be taken in order to use TEM as a reliable thickness measurement technique; that single wavelength ellipsometry can be used with great accuracy and reproducibility for the 50 and 120 nm film thicknesses but that it shows some inherent problems for the 10 nm films; and that spectroscopic ellipsometry showed for all film thicknesses an accuracy and reproducibility which is clearly superior to that of SWE.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.711
Times cited: 13
DOI: 10.1016/0169-4332(93)90062-G
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“Saddle point states and energy barriers for vortex entrance and exit in superconducting disks and rings”. Baelus BJ, Peeters FM, Schweigert VA, Physical review : B : condensed matter and materials physics 63, 144517 (2001). http://doi.org/10.1103/PhysRevB.63.144517
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 86
DOI: 10.1103/PhysRevB.63.144517
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“Scattering of ballistic electrons at a mesoscopic spot of strong magnetic field”. Novoselov KS, Geim AK, Dubonos SV, Cornelissens YG, Peeters FM, Maan JC, Physical review : B : condensed matter and materials physics 65, 233312 (2002). http://doi.org/10.1103/PhysRevB.65.233312
Abstract: We report quenching of the Hall effect with increasing magnetic field confined in a micron-sized spot. Such fields were created by placing tall ferromagnetic pillars on top of a two-dimensional electron gas, which allowed us to achieve the field strength up to 0.4 T under the pillars in the absence of external field. The quenching is accompanied by an anomalous increase in resistance and occurs when the cyclotron diameter matches the size of the magnetic spot. The results are explained by a rapid increase in the number of electrons that are scattered or quasilocalized by the magnetic region.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 38
DOI: 10.1103/PhysRevB.65.233312
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“Screening of the electron-phonon interaction in quasi-one-dimensional semiconductor structures”. Hai GQ, Peeters FM, Devreese JT, Wendler L, Physical review : B : condensed matter and materials physics 48, 12016 (1993). http://doi.org/10.1103/PhysRevB.48.12016
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 3.736
Times cited: 41
DOI: 10.1103/PhysRevB.48.12016
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“Selective decoration of isolated carbon nanotubes by potassium evaporation : scanning photoemission microscopy and density functional theory”. Struzzi C, Erbahar D, Scardamaglia M, Amati M, Gregoratti L, Lagos, Van Tendeloo G, Snyders R, Ewels C, Bittencourt C, Journal of materials chemistry C : materials for optical and electronic devices 3, 2518 (2015). http://doi.org/10.1039/c4tc02478h
Abstract: Site selective doping of aligned carbon nanostructures represents a promising approach for their implementation in actual devices. In the present work we report on alkali metals decoration on low density vertically aligned carbon nanotubes, disclosing the possibility of engineering site selective depositions of potassium atoms on the carbon systems. Photoemission measurements were combined with microscopy demonstrating the effective spatial control of alkali deposition. The changes of electronic structures of locally doped carbon regions were studied by exploiting the ability of the scanning photoemission microscopy technique. From the analysis of experimental data supported by theoretical calculations, we show the tuning of the charge transfer from potassium to carbon atoms belonging to neighboring nanotubes or along the same tube structure.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 5.256
Times cited: 6
DOI: 10.1039/c4tc02478h
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“Self-limiting oxidation in small-diameter Si nanowires”. Khalilov U, Pourtois G, van Duin ACT, Neyts EC, Chemistry of materials 24, 2141 (2012). http://doi.org/10.1021/cm300707x
Abstract: Recently, core shell silicon nanowires (Si-NWs) have been envisaged to be used for field-effect transistors and photovoltaic applications. In spite of the constant downsizing of such devices, the formation of ultrasmall diameter core shell Si-NWs currently remains entirely unexplored. We report here on the modeling of the formation of such core shell Si-NWs using a dry thermal oxidation of 2 nm diameter (100) Si nanowires at 300 and 1273 K, by means of reactive molecular dynamics simulations using the ReaxFF potential. Two different oxidation mechanisms are discussed, namely a self-limiting process that occurs at low temperature (300 K), resulting in a Si core I ultrathin SiO2 silica shell nanowire, and a complete oxidation process that takes place at a higher temperature (1273 K), resulting in the formation of an ultrathin SiO2 silica nanowire. The oxidation kinetics of both cases and the resulting structures are analyzed in detail. Our results demonstrate that precise control over the Si-core radius of such NWs and the SiOx (x <= 2.0) oxide shell is possible by controlling the growth temperature used during the oxidation process.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 9.466
Times cited: 45
DOI: 10.1021/cm300707x
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“Semisolid structure for M2 high speed steel prepared by cooling slope”. Amin-Ahmadi B, Aashuri H, Journal of materials processing technology 210, 1632 (2010). http://doi.org/10.1016/j.jmatprotec.2010.05.011
Abstract: Effects of cooling slope angle and the temperature of molten metal on the globular structure of M2 high speed steel after holding at the semisolid state have been investigated. The globular structure was achieved by pouring the molten metal at 1595 °C on the ceramic cooling slope with the length of 200 mm and the angle of 25°. The globular structure of M2 high speed steel in the form of rolledannealed and as cast condition after holding at semisolid state has been achieved. The size of globular grains of cooling slope sample was smaller than that of the rolledannealed and as cast samples. Solid particles of rolledannealed sample after holding at semisolid state had better roundness compared with cooling slope sample. Dissolution of carbides in the austenite phase at grain boundaries leads to formation of globular particles in the semisolid state. MC-type and M6C-type eutectic carbides reprecipitate during cooling cycle along grain boundaries.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.147
Times cited: 12
DOI: 10.1016/j.jmatprotec.2010.05.011
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“Shallow donor impurities in GaAs/AlxGa1-xAs superlattices in a magnetic-field”. Shi JM, Peeters FM, Devreese JT, Physical review : B : condensed matter and materials physics 50, 15182 (1994). http://doi.org/10.1103/PhysRevB.50.15182
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems
Impact Factor: 3.736
Times cited: 71
DOI: 10.1103/PhysRevB.50.15182
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“Shape resonances in the superconducting order parameter of ultrathin nanowires”. Shanenko AA, Croitoru MD, Physical review : B : condensed matter and materials physics 73, 012510 (2006). http://doi.org/10.1103/PhysRevB.73.012510
Keywords: A1 Journal article; Condensed Matter Theory (CMT); Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 41
DOI: 10.1103/PhysRevB.73.012510
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“Shape selective growth of single crystalline MnOOH multipods and 1D nanowires by a reductive hydrothermal method”. Mi Y, Zhang X, Yang Z, Li Y, Zhou S, Zhang H, Zhu W, He D, Wang J, Van Tendeloo G, Materials letters 61, 1781 (2007). http://doi.org/10.1016/j.matlet.2006.07.130
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.572
Times cited: 13
DOI: 10.1016/j.matlet.2006.07.130
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“Short-range order of Br and three-dimensional magnetism in (CuBr)LaNb2O7”. Tsirlin AA, Abakumov AM, Ritter C, Henry PF, Janson O, Rosner H, Physical review : B : condensed matter and materials physics 85, 214427 (2012). http://doi.org/10.1103/PhysRevB.85.214427
Abstract: We present a comprehensive study of the crystal structure, magnetic structure, and microscopic magnetic model of (CuBr)LaNb2O7, the Br analog of the spin-gap quantum magnet (CuCl) LaNb2O7. Despite similar crystal structures and spin lattices, the magnetic behavior and even peculiarities of the atomic arrangement in the Cl and Br compounds are very different. The high- resolution x-ray and neutron data reveal a split position of Br atoms in (CuBr) LaNb2O7. This splitting originates from two possible configurations developed by [CuBr] zigzag ribbons. While the Br atoms are locally ordered in the ab plane, their arrangement along the c direction remains partially disordered. The predominant and energetically more favorable configuration features an additional doubling of the c lattice parameter that was not observed in (CuCl) LaNb2O7. (CuBr) LaNb2O7 undergoes long-range antiferromagnetic ordering at T-N = 32 K, which is nearly 70% of the leading exchange coupling J4 similar or equal to 48 K. The Br compound does not show any experimental signatures of low-dimensional magnetism because the underlying spin lattice is three-dimensional. The coupling along the c direction is comparable to the couplings in the ab plane, even though the shortest Cu-Cu distance along c (11.69 angstrom) is three times larger than nearest-neighbor distances in the ab plane (3.55 angstrom). The stripe antiferromagnetic long-range order featuring columns of parallel spins in the ab plane and antiparallel spins along c is verified experimentally and confirmed by the microscopic analysis.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.836
Times cited: 5
DOI: 10.1103/PhysRevB.85.214427
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“Signatures of lateral coupling of double quantum dots in the exciton photoluminescence spectrum”. Szafran B, Peeters FM, Physical review : B : condensed matter and materials physics 76, 195442 (2007). http://doi.org/10.1103/PhysRevB.76.195442
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 29
DOI: 10.1103/PhysRevB.76.195442
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“Single and vertically coupled type-II quantum dots in a perpendicular magnetic field: exciton ground-state properties”. Janssens KL, Partoens B, Peeters FM, Physical review : B : condensed matter and materials physics 66, 075314 (2002). http://doi.org/10.1103/PhysRevB.66.075314
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 3.836
Times cited: 38
DOI: 10.1103/PhysRevB.66.075314
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“Single layer vs bilayer graphene : a comparative study of the effects of oxygen plasma treatment on their electronic and optical properties”. Nourbakhsh A, Cantoro M, Klekachev AV, Pourtois G, Vosch T, Hofkens J, van der Veen MH, Heyns MM, de Gendt S, Sels BF, The journal of physical chemistry: C : nanomaterials and interfaces 115, 16619 (2011). http://doi.org/10.1021/jp203010z
Abstract: This contribution presents the effects of a mild O2 plasma treatment on the structural, optical, and electrical properties of single-layer (SLG) and bilayer graphene (BLG). Unexpectedly, we observe only photoluminescence in the SLG parts of a graphene flake composed of regions of various thickness upon O2 plasma treatment, whereas the BLG and few-layer graphene (FLG) parts remain optically unchanged. Confirmed with X-ray photoelectron spectroscopy (XPS) that O2 plasma induces epoxide and hydroxyl-like groups in graphene, density functional theory (DFT) calculations are carried out on representative epoxidized and hydroxylated SLG and BLG models to predict density of states (DOS) and band structures. Sufficiently oxidized SLG shows a bandgap and thus loss of semimetallic behavior, while oxidized BLG maintains its semimetallic behavior even at high oxygen density in agreement with the results of the photoluminescence spectroscopy (PL) experiments. DFT calculations confirm that the Fermi velocity in epoxidized BLG is remarkably comparable with that of pristine SLG, pointing to a similarity of electronic band structure. The similarity is also experimentally demonstrated by the electrical characterization of a plasma-treated BLG-FET. As expected from the electronegative oxygen adatoms in the graphene, epoxidized BLG presents conductive features typical of hole doping. Moreover, the electrical characteristics suggest band structures closely related to that of epoxidized graphene while deviating from that of hydroxylated graphene. Finally, upon O2 plasma treatment of BLG, the four-component 2D peak around 2700 cm1 in the Raman spectrum evolves into a single Lorentzian line, very like the 2D peak of pristine SLG. Summarizing, the data in this contribution recommend that a controlled O2 plasma treatment, which is compatible with CMOS process flow in contrast to wet chemical oxidation methods, provides an efficient and valuable technique to exploit the transport properties of the bottom layer of BLG.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.536
Times cited: 46
DOI: 10.1021/jp203010z
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