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Author Lu, A.K.A.; Houssa, M.; Luisier, M.; Pourtois, G.
Title Impact of layer alignment on the behavior of MoS2-ZrS2 tunnel field-effect transistors : an ab initio study Type A1 Journal article
Year 2017 Publication Physical review applied Abbreviated Journal Phys Rev Appl
Volume 8 Issue 3 Pages (down) 034017
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Tunnel field-effect transistors based on van der Waals heterostructures are emerging device concepts for low-power applications, auguring sub-60 mV/dec subthreshold swing values. In these devices, the channel is built from a stack of several different two-dimensional materials whose nature allows tailoring the band alignments and enables a good electrostatic control of the device. In this work, we propose a theoretical study of the variability of the performances of a MoS2-ZrS2 tunnel field-effect transistor induced by fluctuations of the relative position or the orientation of the layers. Our results indicate that although a steep subthreshold slope (20 mV/dec) is achievable, fluctuations in the relative orientation of the ZrS2 layer with respect to the MoS2 one lead to a significant variability in the tunneling current by about one decade. This arises from changes in the orbital overlap between the layers and from the modulation of the transport direction.
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Corporate Author Thesis
Publisher American Physical Society Place of Publication College Park, Md Editor
Language Wos 000411460400001 Publication Date 2017-09-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2331-7019 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.808 Times cited 6 Open Access OpenAccess
Notes Approved Most recent IF: 4.808
Call Number UA @ lucian @ c:irua:146741 Serial 4785
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Author De Clercq, M.; Moors, K.; Sankaran, K.; Pourtois, G.; Dutta, S.; Adelmann, C.; Magnus, W.; Sorée, B.
Title Resistivity scaling model for metals with conduction band anisotropy Type A1 Journal article
Year 2018 Publication Physical review materials Abbreviated Journal
Volume 2 Issue 3 Pages (down) 033801
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract It is generally understood that the resistivity of metal thin films scales with film thickness mainly due to grain boundary and boundary surface scattering. Recently, several experiments and ab initio simulations have demonstrated the impact of crystal orientation on resistivity scaling. The crystal orientation cannot be captured by the commonly used resistivity scaling models and a qualitative understanding of its impact is currently lacking. In this work, we derive a resistivity scaling model that captures grain boundary and boundary surface scattering as well as the anisotropy of the band structure. The model is applied to Cu and Ru thin films, whose conduction bands are (quasi-) isotropic and anisotropic, respectively. After calibrating the anisotropy with ab initio simulations, the resistivity scaling models are compared to experimental resistivity data and a renormalization of the fitted grain boundary reflection coefficient can be identified for textured Ru.
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Corporate Author Thesis
Publisher American Physical Society Place of Publication College Park, Md Editor
Language Wos 000426787600001 Publication Date 2018-03-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2475-9953 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes ; The authors acknowledge the support by the Fonds National de la Recherche Luxembourg (ATTRACT Grant No. 7556175). ; Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:149866UA @ admin @ c:irua:149866 Serial 4947
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Author Vohra, A.; Khanam, A.; Slotte, J.; Makkonen, I.; Pourtois, G.; Loo, R.; Vandervorst, W.
Title Evolution of phosphorus-vacancy clusters in epitaxial germanium Type A1 Journal article
Year 2019 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 125 Issue 2 Pages (down) 025701
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The E centers (dopant-vacancy pairs) play a significant role in dopant deactivation in semiconductors. In order to gain insight into dopant-defect interactions during epitaxial growth of in situ phosphorus doped Ge, positron annihilation spectroscopy, which is sensitive to open-volume defects, was performed on Ge layers grown by chemical vapor deposition with different concentrations of phosphorus (similar to 1 x 10(18)-1 x 10(20) cm(-3)). Experimental results supported by first-principles calculations based on the two component density-functional theory gave evidence for the existence of mono-vacancies decorated by several phosphorus atoms as the dominant defect type in the epitaxial Ge. The concentration of vacancies increases with the amount of P-doping. The number of P atoms around the vacancy also increases, depending on the P concentration. The evolution of P-n-V clusters in Ge contributes significantly to the dopant deactivation. Published under license by AIP Publishing.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000455922100057 Publication Date 2019-01-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; 1089-7550 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 5 Open Access Not_Open_Access
Notes Approved Most recent IF: 2.068
Call Number UA @ admin @ c:irua:156722 Serial 5274
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Author Dutta, S.; Sankaran, K.; Moors, K.; Pourtois, G.; Van Elshocht, S.; Bommels, J.; Vandervorst, W.; Tokei, Z.; Adelmann, C.
Title Thickness dependence of the resistivity of platinum-group metal thin films Type A1 Journal article
Year 2017 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 122 Issue 2 Pages (down) 025107
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We report on the thin film resistivity of several platinum-group metals (Ru, Pd, Ir, and Pt). Platinum-group thin films show comparable or lower resistivities than Cu for film thicknesses below about 5 nm due to a weaker thickness dependence of the resistivity. Based on experimentally determined mean linear distances between grain boundaries as well as ab initio calculations of the electron mean free path, the data for Ru, Ir, and Cu were modeled within the semiclassical Mayadas-Shatzkes model [Phys. Rev. B 1, 1382 (1970)] to assess the combined contributions of surface and grain boundary scattering to the resistivity. For Ru, the modeling results indicated that surface scattering was strongly dependent on the surrounding material with nearly specular scattering at interfaces with SiO2 or air but with diffuse scattering at interfaces with TaN. The dependence of the thin film resistivity on the mean free path is also discussed within the Mayadas-Shatzkes model in consideration of the experimental findings. Published by AIP Publishing.
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Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000405663800038 Publication Date 2017-07-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; 1089-7550 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 42 Open Access Not_Open_Access
Notes Approved Most recent IF: 2.068
Call Number UA @ lucian @ c:irua:145213 Serial 4729
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Author Khalilov, U.; Neyts, E.C.; Pourtois, G.; van Duin, A.C.T.
Title Can we control the thickness of ultrathin silica layers by hyperthermal silicon oxidation at room temperature? Type A1 Journal article
Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 115 Issue 50 Pages (down) 24839-24848
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Using reactive molecular dynamics simulations by means of the ReaxFF potential, we studied the growth mechanism of ultrathin silica (SiO2) layers during hyperthermal oxidation at room temperature. Oxidation of Si(100){2 × 1} surfaces by both atomic and molecular oxygen was investigated in the energy range 15 eV. The oxidation mechanism, which differs from thermal oxidation, is discussed. In the case of oxidation by molecular O2, silica is quickly formed and the thickness of the formed layers remains limited compared to oxidation by atomic oxygen. The Si/SiO2 interfaces are analyzed in terms of partial charges and angle distributions. The obtained structures of the ultrathin SiO2 films are amorphous, including some intrinsic defects. This study is important for the fabrication of silica-based devices in the micro- and nanoelectronics industry, and more specifically for the fabrication of metal oxide semiconductor devices.
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Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000297947700050 Publication Date 2011-11-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 36 Open Access
Notes Approved Most recent IF: 4.536; 2011 IF: 4.805
Call Number UA @ lucian @ c:irua:94303 Serial 273
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Author Khalilov, U.; Pourtois, G.; van Duin, A.C.T.; Neyts, E.C.
Title On the c-Si\mid a-SiO2 interface in hyperthermal Si oxidation at room temperature Type A1 Journal article
Year 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 116 Issue 41 Pages (down) 21856-21863
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The exact structure and properties of the Si vertical bar SiO2 interface are very important in microelectronics and photovoltaic devices such as metal-oxide-semiconductor field-effect transistors (MOSFETs) and solar cells. Whereas Si vertical bar SiO2 structures are traditionally produced by thermal oxidation, hyperthermal oxidation shows a number of promising advantages. However, the Si vertical bar SiO2 interface induced in hyperthermal Si oxidation has not been properly investigated yet. Therefore, in this work, the interface morphology and interfacial stresses during hyperthermal oxidation at room temperature are studied using reactive molecular dynamics simulations based on the ReaxFF potential. Interface thickness and roughness, as well as the bond length and bond angle distributions in the interface are discussed and compared with other models developed for the interfaces induced by traditional thermal oxidation. The formation of a compressive stress is observed. This compressive stress, which at the interface amounts about 2 GPa, significantly slows down the inward silica growth. This value is close to the experimental value in the Si vertical bar SiO2 interface obtained in traditional thermal oxidation.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000309902100026 Publication Date 2012-09-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 27 Open Access
Notes Approved Most recent IF: 4.536; 2012 IF: 4.814
Call Number UA @ lucian @ c:irua:102167 Serial 2458
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Author van den Broek, B.; Houssa, M.; Scalise, E.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A.
Title Two-dimensional hexagonal tin : ab initio geometry, stability, electronic structure and functionalization Type A1 Journal article
Year 2014 Publication 2D materials Abbreviated Journal 2D Mater
Volume 1 Issue Pages (down) 021004
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We study the structural, mechanical and electronic properties of the two-dimensional (2D) allotrope of tin: tinene/stanene using first-principles calculation within density functional theory, implemented in a set of computer codes. Continuing the trend of the group-IV 2D materials graphene, silicene and germanene; tinene is predicted to have a honeycomb lattice with lattice parameter of a(0) = 4.62 angstrom and a buckling of d(0) = 0.92 angstrom. The electronic dispersion shows a Dirac cone with zero gap at the Fermi energy and a Fermi velocity of v(F) = 0.97 x 10(6) m s(-1); including spin-orbit coupling yields a bandgap of 0.10 eV. The monolayer is thermally stable up to 700 K, as indicated by first-principles molecular dynamics, and has a phonon dispersion without imaginary frequencies. We explore applied electric field and applied strain as functionalization mechanisms. Combining these two mechanisms allows for an induced bandgap up to 0.21 eV, whilst retaining the linear dispersion, albeit with degraded electronic transport parameters.
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Corporate Author Thesis
Publisher IOP Publishing Place of Publication Bristol Editor
Language Wos 000353650400004 Publication Date 2014-08-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.937 Times cited 58 Open Access
Notes Approved Most recent IF: 6.937; 2014 IF: NA
Call Number UA @ lucian @ c:irua:134432 Serial 4530
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Author Phung, Q.M.; Vancoillie, S.; Pourtois, G.; Swerts, J.; Pierloot, K.; Delabie, A.
Title Atomic layer deposition of ruthenium on a titanium nitride surface : a density functional theory study Type A1 Journal article
Year 2013 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 117 Issue 38 Pages (down) 19442-19453
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Because of its excellent properties in nanotechnology applications, atomic layer deposition of ruthenium (Ru) has been the subject of numerous experimental studies. Recently, two different Ru precursors were compared for plasma-enhanced atomic layer deposition (PEALD) of Ru, and their reactivity was found to be different. Inhibition was observed for bis(ethylcyclopentadienyl)ruthenium (Ru(EtCp)(2)), while nearly linear growth behavior was observed for (methylcyclopentadienyl-pyrrolyl)ruthenium (Ru(MeCp)Py). To understand this difference in reactivity, we investigate the adsorption of RuCp, and RuCpPy (i.e., without substituents) on a TiN surface using calculations based on periodic boundary conditions density functional theory (DFT) combined with experiments based on Rutherford backscattering spectroscopy (RBS). The calculations demonstrate that the RuCpPy precursor chemisorbs on the TiN(100) surface while the RuCp2 precursor only physisorbs. We propose a reaction mechanism for the chemisorption of RuCpPy. The area density of the calculated RuCpPy surface species is compared with the experimental values from RBS. The impact of a H-plasma is also investigated. The DFT calculations and experimental results from RBS provide insight into the adsorption processes of the RuCpPy and RuCp2 precursors on the TiN(100) surface.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000330162500022 Publication Date 2013-08-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 6 Open Access
Notes Approved Most recent IF: 4.536; 2013 IF: 4.835
Call Number UA @ lucian @ c:irua:114855 Serial 170
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Author Delabie, A.; Sioncke, S.; Rip, J.; van Elshocht, S.; Caymax, M.; Pourtois, G.; Pierloot, K.
Title Mechanisms for the trimethylaluminum reaction in aluminum oxide atomic layer deposition on sulfur passivated germanium Type A1 Journal article
Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 115 Issue 35 Pages (down) 17523-17532
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Germanium combined with high-κ dielectrics is investigated for the next generations of CMOS devices. Therefore, we study reaction mechanisms for Al2O3 atomic layer deposition on sulfur passivated Ge using calculations based on density functional theory and total reflection X-ray fluorescence (TXRF). TXRF indicates 6 S/nm2 and 4 Al/nm2 after the first TMA/H2O reaction cycle, and growth inhibition from the second reaction cycle on. Calculations are performed on molecular clusters representing −GeSH surface sites. The calculations confirm that the TMA reaction does not affect the S content. On fully SH-terminated Ge, TMA favorably reacts with up to three −GeSH sites, resulting in a near tetrahedral Al coordination. Electron deficient structures with a GeS site shared between two Al atoms are proposed. The impact of the cluster size on the structures and reaction energetics is systematically investigated.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000294386000037 Publication Date 2011-08-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 9 Open Access
Notes Approved Most recent IF: 4.536; 2011 IF: 4.805
Call Number UA @ lucian @ c:irua:91714 Serial 1980
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Author Nourbakhsh, A.; Cantoro, M.; Klekachev, A.V.; Pourtois, G.; Vosch, T.; Hofkens, J.; van der Veen, M.H.; Heyns, M.M.; de Gendt, S.; Sels, B.F.
Title Single layer vs bilayer graphene : a comparative study of the effects of oxygen plasma treatment on their electronic and optical properties Type A1 Journal article
Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 115 Issue 33 Pages (down) 16619-16624
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
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.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000294077000047 Publication Date 2011-06-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 46 Open Access
Notes Approved Most recent IF: 4.536; 2011 IF: 4.805
Call Number UA @ lucian @ c:irua:91715 Serial 3024
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Author Schoeters, B.; Neyts, E.C.; Khalilov, U.; Pourtois, G.; Partoens, B.
Title Stability of Si epoxide defects in Si nanowires : a mixed reactive force field/DFT study Type A1 Journal article
Year 2013 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 15 Issue 36 Pages (down) 15091-15097
Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Modeling the oxidation process of silicon nanowires through reactive force field based molecular dynamics simulations suggests that the formation of Si epoxide defects occurs both at the Si/SiOx interface and at the nanowire surface, whereas for flat surfaces, this defect is experimentally observed to occur only at the interface as a result of stress. In this paper, we argue that the increasing curvature stabilizes the defect at the nanowire surface, as suggested by our density functional theory calculations. The latter can have important consequences for the opto-electronic properties of thin silicon nanowires, since the epoxide induces an electronic state within the band gap. Removing the epoxide defect by hydrogenation is expected to be possible but becomes increasingly difficult with a reduction of the diameter of the nanowires.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000323520600029 Publication Date 2013-07-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 3 Open Access
Notes ; BS gratefully acknowledges financial support of the IWT, Institute for the Promotion of Innovation by Science and Technology in Flanders, via the SBO project “SilaSol”. This work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish government and the Universiteit Antwerpen. ; Approved Most recent IF: 4.123; 2013 IF: 4.198
Call Number UA @ lucian @ c:irua:110793 Serial 3130
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Author van den Broek, B.; Houssa, M.; Iordanidou, K.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A.
Title Functional silicene and stanene nanoribbons compared to graphene: electronic structure and transport Type A1 Journal article
Year 2016 Publication 2D materials Abbreviated Journal 2D Mater
Volume 3 Issue 1 Pages (down) 015001
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Since the advent of graphene, other 2D materials have garnered interest; notably the single element materials silicene, germanene, and stanene. Weinvestigate the ballistic current-voltage (I-V) characteristics of armchair silicene and stanene armchair nanoribbons (AXNRs with X = Si, Sn) using a combination of density functional theory and non-equilibrium Green's functions. The impact of out-of-plane electric field and in-plane uniaxial strain on the ribbon geometries, electronic structure, and (I-V)s are considered and contrasted with graphene. Since silicene and stanene are sp(2)/sp(3) buckled layers, the electronic structure can be tuned by an electric field that breaks the sublattice symmetry, an effect absent in graphene. This decreases the current by similar to 50% for Sn, since it has the largest buckling. Uniaxial straining of the ballistic channel affects the AXNR electronic structure in multiple ways: it changes the bandgap and associated effective carrier mass, and creates a local buckling distortion at the lead-channel interface which induces a interface dipole. Due to the increasing sp(3) hybridization character with increasing element mass, large reconstructions rectify the strained systems, an effect absent in sp(2) bonded graphene. This results in a smaller strain effect on the current: a decrease of 20% for Sn at 15% tensile strain compared to a similar to 75% decrease for C.
Address
Corporate Author Thesis
Publisher IOP Publishing Place of Publication Bristol Editor
Language Wos 000373936300021 Publication Date 2016-01-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.937 Times cited 19 Open Access
Notes Approved Most recent IF: 6.937
Call Number UA @ lucian @ c:irua:144746 Serial 4658
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Author Scalise, E.; Houssa, M.; Cinquanta, E.; Grazianetti, C.; van den Broek, B.; Pourtois, G.; Stesmans, A.; Fanciulli, M.; Molle, A.
Title Engineering the electronic properties of silicene by tuning the composition of MoX2 and GaX (X = S,Se,Te) chalchogenide templates Type A1 Journal article
Year 2014 Publication 2D materials Abbreviated Journal 2D Mater
Volume 1 Issue 1 Pages (down) 011010
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract By using first-principles simulations, we investigate the interaction of a 2D silicon layer with two classes of chalcogenide-layered compounds, namely MoX2 and GaX (X = S, Se, Te). A rather weak (van der Waals) interaction between the silicene layers and the chalcogenide layers is predicted. We found that the buckling of the silicene layer is correlated to the lattice mismatch between the silicene layer and the MoX2 or GaX template. The electronic properties of silicene on these different templates largely depend on the buckling of the silicene layer: highly buckled silicene on MoS2 is predicted to be metallic, while low buckled silicene on GaS and GaSe is predicted to be semi-metallic, with preserved Dirac cones at the K points. These results indicate new routes for artificially engineering silicene nanosheets, providing tailored electronic properties of this 2D layer on non-metallic substrates. These non-metallic templates also open the way to the possible integration of silicene in future nanoelectronic devices.
Address
Corporate Author Thesis
Publisher IOP Publishing Place of Publication Bristol Editor
Language Wos 000353649900011 Publication Date 2014-05-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.937 Times cited 49 Open Access
Notes Approved Most recent IF: 6.937; 2014 IF: NA
Call Number UA @ lucian @ c:irua:126032 Serial 1048
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Author Khalilov, U.; Pourtois, G.; Huygh, S.; van Duin, A.C.T.; Neyts, E.C.; Bogaerts, A.
Title New mechanism for oxidation of native silicon oxide Type A1 Journal article
Year 2013 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 117 Issue 19 Pages (down) 9819-9825
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Continued miniaturization of metal-oxide-semiconductor field-effect transistors (MOSFETs) requires an ever-decreasing thickness of the gate oxide. The structure of ultrathin silicon oxide films, however, critically depends on the oxidation mechanism. Using reactive atomistic simulations, we here demonstrate how the oxidation mechanism in hyperthermal oxidation of such structures may be controlled by the oxidation temperature and the oxidant energy. Specifically, we study the interaction of hyperthermal oxygen with energies of 15 eV with thin SiOx (x ≤ 2) films with a native oxide thickness of about 10 Å. We analyze the oxygen penetration depth probability and compare with results of the hyperthermal oxidation of a bare Si(100){2 × 1} (c-Si) surface. The temperature-dependent oxidation mechanisms are discussed in detail. Our results demonstrate that, at low (i.e., room) temperature, the penetrated oxygen mostly resides in the oxide region rather than at the SiOx|c-Si interface. However, at higher temperatures, starting at around 700 K, oxygen atoms are found to penetrate and to diffuse through the oxide layer followed by reaction at the c-Si boundary. We demonstrate that hyperthermal oxidation resembles thermal oxidation, which can be described by the DealGrove model at high temperatures. Furthermore, defect creation mechanisms that occur during the oxidation process are also analyzed. This study is useful for the fabrication of ultrathin silicon oxide gate oxides for metal-oxide-semiconductor devices as it links parameters that can be straightforwardly controlled in experiment (oxygen temperature, velocity) with the silicon oxide structure.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000319649100032 Publication Date 2013-04-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 24 Open Access
Notes Approved Most recent IF: 4.536; 2013 IF: 4.835
Call Number UA @ lucian @ c:irua:107989 Serial 2321
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Author Khalilov, U.; Pourtois, G.; van Duin, A.C.T.; Neyts, E.C.
Title Hyperthermal oxidation of Si(100)2x1 surfaces : effect of growth temperature Type A1 Journal article
Year 2012 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 116 Issue 15 Pages (down) 8649-8656
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Using reactive molecular dynamics simulations based on the ReaxFF potential, we studied the growth mechanism of ultrathin silica (SiO2) layers during hyperthermal oxidation as a function of temperature in the range 100-1300 K. Oxidation of Si(100){2 x 1} surfaces by both atomic and molecular oxygen was investigated for hyperthermal impact energies in the range of 1 to 5 eV. Two different growth mechanisms are found, corresponding to a low temperature oxidation and a high temperature one. The transition temperature between these mechanisms is estimated to be about 700 K. Also, the initial step of the Si oxidation process is analyzed in detail. Where possible, we validated our results with experimental and ab initio data, and good agreement was obtained. This study is important for the fabrication of silica-based devices in the micro- and nanoelectronics industry and, more specifically, for the fabrication of metal oxide semiconductor devices.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000302924900035 Publication Date 2012-03-26
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 32 Open Access
Notes Approved Most recent IF: 4.536; 2012 IF: 4.814
Call Number UA @ lucian @ c:irua:98259 Serial 1542
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Author Lu, A.K.A.; Houssa, M.; Radu, I.P.; Pourtois, G.
Title Toward an understanding of the electric field-induced electrostatic doping in van der Waals heterostructures : a first-principles study Type A1 Journal article
Year 2017 Publication ACS applied materials and interfaces Abbreviated Journal Acs Appl Mater Inter
Volume 9 Issue 8 Pages (down) 7725-7734
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Since the discovery of graphene, a broad range of two-dimensional (2D) materials has captured the attention of the scientific communities. Materials, such as hexagonal boron nitride (hBN) and the transition metal dichalcogenides (TMDs) family, have shown promising semiconducting and insulating properties that are very appealing for the semiconductor industry. Recently, the possibility of taking advantage of the properties of 2D-based heterostructures has been investigated for low-power nanoelectronic applications. In this work, we aim at evaluating the relation between the nature of the materials used in such heterostructures and the amplitude of the layer-to-layer charge transfer induced by an external electric field, as is typically present in nanoelectronic gated devices. A broad range of combinations of TMDs, graphene, and hBN has been investigated using density functional theory. Our results show that the electric field induced charge transfer strongly depends on the nature of the 2D materials used in the van der Waals heterostructures and to a lesser extent on the relative orientation of the materials in the structure. Our findings contribute to the building of the fundamental understanding required to engineer electrostatically the doping of 2D materials and to establish the factors that drive the charge transfer mechanisms in electron tunneling-based devices. These are key ingredients for the development of 2D -based nanoelectronic devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000395494200119 Publication Date 2017-02-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1944-8244 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.504 Times cited 10 Open Access Not_Open_Access
Notes Approved Most recent IF: 7.504
Call Number UA @ lucian @ c:irua:142483 Serial 4696
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Author Quan Manh, P.; Pourtois, G.; Swerts, J.; Pierloot, K.; Delabie, A.
Title Atomic layer deposition of Ruthenium on Ruthenium surfaces : a theoretical study Type A1 Journal article
Year 2015 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 119 Issue 119 Pages (down) 6592-6603
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Atomic, layer deposition,(ALD of ruthenium using two ruthenium precursors, i.e., Ru(C5H5)(2) (RuCp2) and Ru(C5H5)(C4H4N) (RuCpPy), is studied using density functional theory. By investigating the reaction mechanisms On bare ruthenium surfaces, i.e., (001), (101), and (100), and H-terminated surfaces, an atomistic insight in the Ru ALD is provided. The calculated results show that on the Ru surfaces both RuCp2 and RuCpPy an undergo dehydrogenation and ligand dissociation reactions. RuCpPy is more reactive than RuCp2. By forming a, strong, bond between N of Py and Ru of the surface, RuCpPy can easily chemisorb on the surfaces. The reactions of RuCp2,On the Surfaces are less favorable the adsorption is not strong enough This could be a,factor contributing to the higher growth-per-cycle of Ru using RuCpPy, as observed experimentally. By Studying, the adsorption on H-terminated Ru surfaces, We showed that H Can prevent the adsorption of the precursors, thus inhibiting the growth of Ru. Our calculations indicate that the H content on the surface can have an impact on the growth-per-cycle. Finally, our simulations also demonstrate large impacts of the surface structure on the reaction mechanisms. Of the three surfaces, the (100) surface, which is the less stable and has a zigzag surface structure, is also the most reactive one.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000351970800015 Publication Date 2015-03-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 10 Open Access
Notes Approved Most recent IF: 4.536; 2015 IF: 4.772
Call Number c:irua:125544 Serial 171
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Author Mehta, A.N.; Mo, J.; Pourtois, G.; Dabral, A.; Groven, B.; Bender, H.; Favia, P.; Caymax, M.; Vandervorst, W.
Title Grain-boundary-induced strain and distortion in epitaxial bilayer MoS₂ lattice Type A1 Journal article
Year 2020 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C
Volume 124 Issue 11 Pages (down) 6472-6478
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Grain boundaries between 60 degrees rotated and twinned crystals constitute the dominant type of extended line defects in two-dimensional transition metal dichalcogenides (2D MX2) when grown on a single crystalline template through van der Waals epitaxy. The two most common 60 degrees grain boundaries in MX2 layers, i.e., beta- and gamma-boundaries, introduce distinct distortion and strain into the 2D lattice. They impart a localized tensile or compressive strain on the subsequent layer, respectively, due to van der Waals coupling in bilayer MX2 as determined by combining atomic resolution electron microscopy, geometric phase analysis, and density functional theory. Based on these observations, an alternate route to strain engineering through controlling intrinsic van der Waals forces in homobilayer MX2 is proposed. In contrast to the commonly used external means, this approach enables the localized application of strain to tune the electronic properties of the 2D semiconducting channel in ultra-scaled nanoelectronic applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000526396000067 Publication Date 2020-02-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited 2 Open Access
Notes ; ; Approved Most recent IF: 3.7; 2020 IF: 4.536
Call Number UA @ admin @ c:irua:168625 Serial 6528
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Author Neyts, E.C.; Khalilov, U.; Pourtois, G.; van Duin, A.C.T.
Title Hyperthermal oxygen interacting with silicon surfaces : adsorption, implantation, and damage creation Type A1 Journal article
Year 2011 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 115 Issue 15 Pages (down) 4818-4823
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Using reactive molecular dynamics simulations, we have investigated the effect of single-impact, low-energy (thermal-100 eV) bombardment of a Si(100){2 × 1} surface by atomic and molecular oxygen. Penetration probability distributions, as well as defect formation distributions, are presented as a function of the impact energy for both species. It is found that at low impact energy, defects are created chemically due to the chemisorption process in the top layers of the surface, while at high impact energy, additional defects are created by a knock-on displacement of Si. These results are of particular importance for understanding device performances of silica-based microelectronic and photovoltaic devices.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000288401200060 Publication Date 2011-03-02
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447;1932-7455; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 28 Open Access
Notes Approved Most recent IF: 4.536; 2011 IF: 4.805
Call Number UA @ lucian @ c:irua:89858 Serial 1543
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Author Houssa, M.; van den Broek, B.; Scalise, E.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A.
Title An electric field tunable energy band gap at silicene/(0001) ZnS interfaces Type A1 Journal article
Year 2013 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 15 Issue 11 Pages (down) 3702-3705
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The interaction of silicene, the silicon counterpart of graphene, with (0001) ZnS surfaces is investigated theoretically, using first-principles simulations. The charge transfer occurring at the silicene/(0001) ZnS interface leads to the opening of an indirect energy band gap of about 0.7 eV in silicene. Remarkably, the nature (indirect or direct) and magnitude of the energy band gap of silicene can be controlled by an external electric field: the energy gap is predicted to become direct for electric fields larger than about 0.5 V angstrom(-1), and the direct energy gap decreases approximately linearly with the applied electric field. The predicted electric field tunable energy band gap of the silicene/(0001) ZnS interface is very promising for its potential use in nanoelectronic devices.
Address
Corporate Author Thesis
Publisher Place of Publication Cambridge Editor
Language Wos 000315165100002 Publication Date 2013-01-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076;1463-9084; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 74 Open Access
Notes Approved Most recent IF: 4.123; 2013 IF: 4.198
Call Number UA @ lucian @ c:irua:107702 Serial 94
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Author van den Broek, B.; Houssa, M.; Lu, A.; Pourtois, G.; Afanas'ev, V.; Stesmans, A.
Title Silicene nanoribbons on transition metal dichalcogenide substrates : effects on electronic structure and ballistic transport Type A1 Journal article
Year 2016 Publication Nano Research Abbreviated Journal Nano Res
Volume 9 Issue 9 Pages (down) 3394-3406
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The idea of stacking multiple monolayers of different two-dimensional materials has become a global pursuit. In this work, a silicene armchair nanoribbon of width W and van der Waals-bonded to different transition-metal dichalcogenide (TMD) bilayer substrates MoX2 and WX2, where X = S, Se, Te is considered. The orbital resolved electronic structure and ballistic transport properties of these systems are simulated by employing van der Waals-corrected density functional theory and nonequilibrium Green's functions. We find that the lattice mismatch with the underlying substrate determines the electronic structure, correlated with the silicene buckling distortion and ultimately with the contact resistance of the two-terminal system. The smallest lattice mismatch, obtained with the MoTe2 substrate, results in the silicene ribbon properties coming close to those of a freestanding one. With the TMD bilayer acting as a dielectric layer, the electronic structure is tunable from a direct to an indirect semiconducting layer, and subsequently to a metallic electronic dispersion layer, with a moderate applied perpendicular electric field.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000386770300018 Publication Date 2016-08-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1998-0124 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 7.354 Times cited 2 Open Access
Notes Approved Most recent IF: 7.354
Call Number UA @ lucian @ c:irua:138210 Serial 4469
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Author Cornil, D.; Li, H.; Wood, C.; Pourtois, G.; Bredas, J.-L.; Cornil, J.
Title Work-function modification of Au and Ag surfaces upon deposition of self-assembled monolayers : influence of the choice of the theoretical approach and the thiol decomposition scheme Type A1 Journal article
Year 2013 Publication ChemPhysChem : a European journal of chemical physics and physical chemistry Abbreviated Journal Chemphyschem
Volume 14 Issue 13 Pages (down) 2939-2946
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract We have characterized theoretically the work-function modifications of the (111) surfaces of gold and silver upon deposition of self-assembled monolayers based on methanethiol and trifluoromethanethiol. A comparative analysis is made between the experimental results and those obtained from two widely used approaches based on density functional theory. The contributions to the total work-function modifications are estimated on the basis of two decomposition schemes of the thiol molecules that have been proposed in the literature. The contributions are found to differ significantly between the two approaches, as do the corresponding adsorption energies.
Address
Corporate Author Thesis
Publisher Place of Publication Weinheim Editor
Language Wos 000324316000014 Publication Date 2013-07-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1439-4235; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.075 Times cited 9 Open Access
Notes Approved Most recent IF: 3.075; 2013 IF: 3.360
Call Number UA @ lucian @ c:irua:112278 Serial 3923
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Author Khalilov, U.; Pourtois, G.; van Duin, A.C.T.; Neyts, E.C.
Title Self-limiting oxidation in small-diameter Si nanowires Type A1 Journal article
Year 2012 Publication Chemistry of materials Abbreviated Journal Chem Mater
Volume 24 Issue 11 Pages (down) 2141-2147
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
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.
Address
Corporate Author Thesis
Publisher Place of Publication Washington, D.C. Editor
Language Wos 000305092600021 Publication Date 2012-05-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756;1520-5002; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.466 Times cited 45 Open Access
Notes Approved Most recent IF: 9.466; 2012 IF: 8.238
Call Number UA @ lucian @ c:irua:99079 Serial 2976
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Author Neyts, E.C.; Thijsse, B.J.; Mees, M.J.; Bal, K.M.; Pourtois, G.
Title Establishing uniform acceptance in force biased Monte Carlo simulations Type A1 Journal article
Year 2012 Publication Journal of chemical theory and computation Abbreviated Journal J Chem Theory Comput
Volume 8 Issue 6 Pages (down) 1865-1869
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Uniform acceptance force biased Monte Carlo (UFMC) simulations have previously been shown to be a powerful tool to simulate atomic scale processes, enabling one to follow the dynamical path during the simulation. In this contribution, we present a simple proof to demonstrate that this uniform acceptance still complies with the condition of detailed balance, on the condition that the characteristic parameter lambda = 1/2 and that the maximum allowed step size is chosen to be sufficiently small. Furthermore, the relation to Metropolis Monte Carlo (MMC) is also established, and it is shown that UFMC reduces to MMC by choosing the characteristic parameter lambda = 0 [Rao, M. et al. Mol. Phys. 1979, 37, 1773]. Finally, a simple example compares the UFMC and MMC methods.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000305092400002 Publication Date 2012-05-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1549-9618;1549-9626; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 5.245 Times cited 20 Open Access
Notes Approved Most recent IF: 5.245; 2012 IF: 5.389
Call Number UA @ lucian @ c:irua:99090 Serial 1082
Permanent link to this record
 
 
Author Phung, Q.M.; Vancoillie, S.; Delabie, A.; Pourtois, G.; Pierloot, K.
Title Ruthenocene and cyclopentadienyl pyrrolyl ruthenium as precursors for ruthenium atomic layer deposition : a comparative study of dissociation enthalpies Type A1 Journal article
Year 2012 Publication Theoretical chemistry accounts : theory, computation, and modeling Abbreviated Journal Theor Chem Acc
Volume 131 Issue 7 Pages (down) 1238
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract RuCp2 (ruthenocene) and RuCpPy (cyclopentadienyl pyrrolyl ruthenium) complexes are used in ruthenium (Ru) atomic layer deposition (ALD) but exhibit a markedly different reactivity with respect to the substrate and co-reactant. In search of an explanation, we report here the results of a comparative study of the heterolytic and homolytic dissociation enthalpy of these two ruthenium complexes, making use of either density functional theory (DFT) or multiconfigurational perturbation theory (CASPT2). While both methods predict distinctly different absolute dissociation enthalpies, they agree on the relative values between both molecules. A reduced heterolytic dissociation enthalpy is obtained for RuCpPy compared to RuCp2, although the difference obtained from CASPT2 (19.9 kcal/mol) is slightly larger than the one obtained with any of the DFT functionals (around 17 kcal/mol). Both methods also agree on the more pronounced stability of the Cp- ligand in RuCpPy than in RuCp2 (by around 9 kcal/mol with DFT and by 6 kcal/mol with CASPT2).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000307274300003 Publication Date 2012-07-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1432-881X;1432-2234; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.89 Times cited 5 Open Access
Notes Approved Most recent IF: 1.89; 2012 IF: 2.233
Call Number UA @ lucian @ c:irua:101139 Serial 2935
Permanent link to this record
 
 
Author Dabral, A.; Lu, A.K.A.; Chiappe, D.; Houssa, M.; Pourtois, G.
Title A systematic study of various 2D materials in the light of defect formation and oxidation Type A1 Journal article
Year 2019 Publication Physical chemistry, chemical physics Abbreviated Journal Phys Chem Chem Phys
Volume 21 Issue 3 Pages (down) 1089-1099
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract The thermodynamic aspects of various 2D materials are explored using Density Functional Theory (DFT). Various metal chalcogenides (MX2, M = metal, chalcogen X = S, Se, Te) are investigated with respect to their interaction and stability under different ambient conditions met in the integration process of a transistor device. Their interaction with high- dielectrics is also addressed, in order to assess their possible integration in Complementary Metal Oxide Semiconductor (CMOS) field effect transistors. 2D materials show promise for high performance nanoelectronic devices, but the presence of defects (vacancies, grain boundaries,...) can significantly impact their electronic properties. To assess the impact of defects, their enthalpies of formation and their signature levels in the density of states have been studied. We find, consistently with literature reports, that chalcogen vacancies are the most likely source of defects. It is shown that while pristine 2D materials are in general stable whenever set in contact with different ambient atmospheres, the presence of defective sites affects the electronic properties of the 2D materials to varying degrees. We observe that all the 2D materials studied in the present work show strong reactivity towards radical oxygen plasma treatments while reactivity towards other common gas phase chemical such as O-2 and H2O and groups present at the high- surface varies significantly between species. While energy band-gaps, effective masses and contact resistivities are key criteria in selection of 2D materials for scaled CMOS and tunneling based devices, the phase and ambient stabilities might also play a very important role in the development of reliable nanoelectronic applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000456147000009 Publication Date 2018-12-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1463-9076; 1463-9084 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.123 Times cited 1 Open Access Not_Open_Access
Notes Approved Most recent IF: 4.123
Call Number UA @ admin @ c:irua:156715 Serial 5267
Permanent link to this record
 
 
Author Neyts, E.; Maeyens, A.; Pourtois, G.; Bogaerts, A.
Title A density-functional theory simulation of the formation of Ni-doped fullerenes by ion implantation Type A1 Journal article
Year 2011 Publication Carbon Abbreviated Journal Carbon
Volume 49 Issue 3 Pages (down) 1013-1017
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Using self-consistent KohnSham density-functional theory molecular dynamics simulations, we demonstrate the theoretical possibility to synthesize NiC60, the incarfullerene Ni@C60 and the heterofullerene C59Ni in an ion implantation setup. The corresponding formation mechanisms of all three complexes are elucidated as a function of the ion implantation energy and impact location, suggesting possible routes for selectively synthesizing these complexes.
Address
Corporate Author Thesis
Publisher Place of Publication Oxford Editor
Language Wos 000286683500032 Publication Date 2010-11-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0008-6223; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.337 Times cited 13 Open Access
Notes Approved Most recent IF: 6.337; 2011 IF: 5.378
Call Number UA @ lucian @ c:irua:85139 Serial 639
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Author Clima, S.; Belmonte, A.; Degraeve, R.; Fantini, A.; Goux, L.; Govoreanu, B.; Jurczak, M.; Ota, K.; Redolfi, A.; Kar, G.S.; Pourtois, G.
Title Kinetic and thermodynamic heterogeneity : an intrinsic source of variability in Cu-based RRAM memories Type A1 Journal article
Year 2017 Publication Journal of computational electronics Abbreviated Journal J Comput Electron
Volume 16 Issue 4 Pages (down) 1011-1016
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract <script type='text/javascript'>document.write(unpmarked('The resistive random-access memory (RRAM) device concept is close to enabling the development of a new generation of non-volatile memories, provided that their reliability issues are properly understood. The design of a RRAM operating with extrinsic defects based on metallic inclusions, also called conductive bridge RAM, allows the use of a large spectrum of solid electrolytes. However, when scaled to device dimensions that meet the requirements of the latest technological nodes, the discrete nature of the atomic structure of the materials impacts the device operation. Using density functional theory simulations, we evaluated the migration kinetics of Cu conducting species in amorphous and solid electrolyte materials, and established that atomic disorder leads to a large variability in terms of defect stability and kinetic barriers. This variability has a significant impact on the filament resistance and its dynamics, as evidenced during the formation step of the resistive filament. Also, the atomic configuration of the formed filament can age/relax to another metastable atomic configuration, and lead to a modulation of the resistivity of the filament. All these observations are qualitatively explained on the basis of the computed statistical distributions of the defect stability and on the kinetic barriers encountered in RRAM materials.'));
Address
Corporate Author Thesis
Publisher Place of Publication Place of publication unknown Editor
Language Wos 000417598100004 Publication Date 2017-08-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1569-8025 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.526 Times cited 2 Open Access Not_Open_Access
Notes Approved Most recent IF: 1.526
Call Number UA @ lucian @ c:irua:148569 Serial 4883
Permanent link to this record
 
 
Author van den Broek, B.; Houssa, M.; Pourtois, G.; Afanas'ev, V.V.; Stesmans, A.
Title Current-voltage characteristics of armchair Sn nanoribbons Type A1 Journal article
Year 2014 Publication Physica status solidi: rapid research letters Abbreviated Journal Phys Status Solidi-R
Volume 8 Issue 11 Pages (down) 931-934
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Two-dimensional group-IV lattices silicene and germanene are known to share many of graphene's remarkable mechanical and electronic properties. Due to the out-of-plane buckling of the former materials, there are more means of electronic funtionalization, e.g. by applying uniaxial strain or an out-of-plane electric field. We consider monolayer hexagonal Sn (stanene) as an ideal candidate to feasibly implement and exploit graphene physics for nanoelectronic applications: with increased out-of-plane buckling and sizable spin-orbit coupling it lends itself to improved Dirac cone engineering. We investigate the ballistic charge transport regime of armchair Sn nanoribbons, classified according to the ribbon width W = {3m – 1, 3m, 3m + 1} with integer m. We study transport through (non-magnetic) armchair ribbons using a combination of density functional theory and non-equilibrium Green's functions. Sn ribbons have earlier current onsets and carry currents 20% larger than C/Si/Ge-nanoribbons as the contact resistance of these ribbons is found to be comparable. ((c) 2014 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)
Address
Corporate Author Thesis
Publisher Place of Publication Berlin Editor
Language Wos 000345274300009 Publication Date 2014-09-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1862-6254; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.032 Times cited 9 Open Access
Notes Approved Most recent IF: 3.032; 2014 IF: 2.142
Call Number UA @ lucian @ c:irua:122148 Serial 594
Permanent link to this record
 
 
Author Xu, X.; Vereecke, G.; Chen, C.; Pourtois, G.; Armini, S.; Verellen, N.; Tsai, W.K.; Kim, D.W.; Lee, E.; Lin, C.Y.; Van Dorpe, P.; Struyf, H.; Holsteyns, F.; Moshchalkov, V.; Indekeu, J.; De Gendt, S.;
Title Capturing wetting states in nanopatterned silicon Type A1 Journal article
Year 2014 Publication ACS nano Abbreviated Journal Acs Nano
Volume 8 Issue 1 Pages (down) 885-893
Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Spectacular progress in developing advanced Si circuits with reduced size, along the track of Moore's law, has been relying on necessary developments in wet cleaning of nanopatterned Si wafers to provide contaminant free surfaces. The most efficient cleaning is achieved when complete wetting can be realized. In this work, ordered arrays of silicon nanopillars on a hitherto unexplored small scale have been used to study the wetting behavior on nanomodulated surfaces in a substantial range of surface treatments and geometrical parameters. With the use of optical reflectance measurements, the nanoscale water imbibition depths have been measured and the transition to the superhydrophobic Cassie-Baxter state has been accurately determined. For pillars of high aspect ratio (about 15), the transition occurs even when the surface is grafted with a hydrophilic functional group. We have found a striking consistent deviation between the contact angle measurements and the straightforward application of the classical wetting models. Molecular dynamics simulations show that these deviations can be attributed to the long overlooked atomic-scale surface perturbations that are introduced during the nanofabrication process. When the transition condition is approached, transient states of partial imbibition that characterize intermediate states between the Wenzel and Cassie-Baxter states are revealed in our experiments.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000330542900092 Publication Date 2013-12-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851;1936-086X; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 13.942 Times cited 39 Open Access
Notes Approved Most recent IF: 13.942; 2014 IF: 12.881
Call Number UA @ lucian @ c:irua:114871 Serial 276
Permanent link to this record