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Author de de Meux, A.J.; Pourtois, G.; Genoe, J.; Heremans, P. pdf  url
doi  openurl
  Title Effects of hole self-trapping by polarons on transport and negative bias illumination stress in amorphous-IGZO Type A1 Journal article
  Year (down) 2018 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 123 Issue 16 Pages 161513  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract The effects of hole injection in amorphous indium-gallium-zinc-oxide (a-IGZO) are analyzed by means of first-principles calculations. The injection of holes in the valence band tail states leads to their capture as a polaron, with high self-trapping energies (from 0.44 to 1.15 eV). Once formed, they mediate the formation of peroxides and remain localized close to the hole injection source due to the presence of a large diffusion energy barrier (of at least 0.6 eV). Their diffusion mechanism can be mediated by the presence of hydrogen. The capture of these holes is correlated with the low off-current observed for a-IGZO transistors, as well as with the difficulty to obtain a p-type conductivity. The results further support the formation of peroxides as being the root cause of Negative Bias Illumination Stress (NBIS). The strong self-trapping substantially reduces the injection of holes from the contact and limits the creation of peroxides from a direct hole injection. In the presence of light, the concentration of holes substantially rises and mediates the creation of peroxides, responsible for NBIS. Published by AIP Publishing.  
  Address  
  Corporate Author Thesis  
  Publisher Amer inst physics Place of Publication Melville Editor  
  Language Wos 000431147200043 Publication Date 2017-10-19  
  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 4 Open Access OpenAccess  
  Notes Approved Most recent IF: 2.068  
  Call Number UA @ lucian @ c:irua:151570 Serial 5021  
Permanent link to this record
 

 
Author Dutta, S.; Sankaran, K.; Moors, K.; Pourtois, G.; Van Elshocht, S.; Bommels, J.; Vandervorst, W.; Tokei, Z.; Adelmann, C. doi  openurl
  Title Thickness dependence of the resistivity of platinum-group metal thin films Type A1 Journal article
  Year (down) 2017 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 122 Issue 2 Pages 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.  
  Address  
  Corporate Author Thesis  
  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 Ishikawa, K.; Karahashi, K.; Ichiki, T.; Chang, J.P.; George, S.M.; Kessels, W.M.M.; Lee, H.J.; Tinck, S.; Um, J.H.; Kinoshita, K. pdf  url
doi  openurl
  Title Progress and prospects in nanoscale dry processes: How can we control atomic layer reactions? Type A1 Journal article
  Year (down) 2017 Publication Japanese journal of applied physics Abbreviated Journal Jpn J Appl Phys  
  Volume 56 Issue 56 Pages 06HA02  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract In this review, we discuss the progress of emerging dry processes for nanoscale fabrication. Experts in the fields of plasma processing have contributed to addressing the increasingly challenging demands in achieving atomic-level control of material selectivity and physicochemical reactions involving ion bombardment. The discussion encompasses major challenges shared across the plasma science and technology community. Focus is placed on advances in the development of fabrication technologies for emerging materials, especially metallic and intermetallic compounds and multiferroic, and two-dimensional (2D) materials, as well as state-of-the-art techniques used in nanoscale semiconductor manufacturing with a brief summary of future challenges.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000425887900001 Publication Date 2017-06-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-4922 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.384 Times cited 18 Open Access OpenAccess  
  Notes The authors would like to thank Drs. Masanobu Honda, Miyako Matsui, Tomohiro Okumura, Tetsuya Tatsumi, Satoshi Hamaguchi, Hiroto Ohtake, Yoshinobu Ohya, Kazunori Shinoda, Masaru Izawa, Hisataka Hayashi, Toshio Hayashi, Makoto Sekine, and Masaru Hori, and all members of the Program and Publication Committee of the 38th International Symposium on Dry Process 2016 held in Sapporo, Japan, as well as Nicholas Altieri and Jeffrey Chang at UCLA for proofreading and providing feedback on the manuscript. Approved Most recent IF: 1.384  
  Call Number PLASMANT @ plasmant @ c:irua:143872 Serial 4576  
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Author Mohammed, M.; Verhulst, A.S.; Verreck, D.; Van de Put, M.; Simoen, E.; Sorée, B.; Kaczer, B.; Degraeve, R.; Mocuta, A.; Collaert, N.; Thean, A.; Groeseneken, G. url  doi
openurl 
  Title Electric-field induced quantum broadening of the characteristic energy level of traps in semiconductors and oxides Type A1 Journal article
  Year (down) 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 120 Issue 120 Pages 245704  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The trap-assisted tunneling (TAT) current in tunnel field-effect transistors (TFETs) is one of the crucial factors degrading the sub-60 mV/dec sub-threshold swing. To correctly predict the TAT currents, an accurate description of the trap is required. Since electric fields in TFETs typically reach beyond 10(6) V/cm, there is a need to quantify the impact of such high field on the traps. We use a quantum mechanical implementation based on the modified transfer matrix method to obtain the trap energy level. We present the qualitative impact of electric field on different trap configurations, locations, and host materials, including both semiconductors and oxides. We determine that there is an electric-field related trap level shift and level broadening. We find that these electric-field induced quantum effects can enhance the trap emission rates. Published by AIP Publishing.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000392174000028 Publication Date 2016-12-26  
  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 6 Open Access  
  Notes ; This work was supported by imec's Industrial Affiliation Program. D. Verreck acknowledges the support of a PhD stipend from IWT-Vlaanderen. ; Approved Most recent IF: 2.068  
  Call Number UA @ lucian @ c:irua:141481 Serial 4593  
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Author Berdiyorov, G.R.; Mortazavi, B.; Ahzi, S.; Peeters, F.M.; Khraisheh, M.K. url  doi
openurl 
  Title Effect of straining graphene on nanopore creation using Si cluster bombardment: A reactive atomistic investigation Type A1 Journal article
  Year (down) 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 120 Issue 120 Pages 225108  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Graphene nanosheets have recently received a revival of interest as a new class of ultrathin, high-flux, and energy-efficient sieving membranes because of their unique two-dimensional and atomically thin structure, good flexibility, and outstanding mechanical properties. However, for practical applications of graphene for advanced water purification and desalination technologies, the creation of well controlled, high-density, and subnanometer diameter pores becomes a key factor. Here, we conduct reactive force-field molecular dynamics simulations to study the effect of external strain on nanopore creation in the suspended graphene by bombardment with Si clusters. Depending on the size and energy of the clusters, different kinds of topography were observed in the graphene sheet. In all the considered conditions, tensile strain results in the creation of nanopores with regular shape and smooth edges. On the contrary, compressive strain increases the elastic response of graphene to irradiation that leads to the formation of net-like defective structures with predominantly carbon atom chains. Our findings show the possibility of creating controlled nanopores in strained graphene by bombardment with Si clusters. Published by AIP Publishing.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000391535900022 Publication Date 2016-12-15  
  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 10 Open Access  
  Notes ; ; Approved Most recent IF: 2.068  
  Call Number UA @ lucian @ c:irua:141451 Serial 4554  
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Author Fatima; Oguz, I.C.; Çakir, D.; Hossain, S.; Mohottige, R.; Gulseren, O.; Oncel, N. url  doi
openurl 
  Title On the structural and electronic properties of Ir-silicide nanowires on Si(001) surface Type A1 Journal article
  Year (down) 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 120 Issue 120 Pages 095303  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Iridium (Ir) modified Silicon (Si) (001) surface is studied with Scanning Tunneling Microscopy/Spectroscopy (STM/STS) and Density Functional Theory (DFT). A model for Ir-silicide nanowires based on STM images and ab-initio calculations is proposed. According to our model, the Ir adatom is on the top of the substrate dimer row and directly binds to the dimer atoms. I-V curves measured at 77K shows that the nanowires are metallic. DFT calculations confirm strong metallic nature of the nanowires. Published by AIP Publishing.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000383978100030 Publication Date 2016-09-01  
  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 7 Open Access  
  Notes ; We gratefully acknowledge the NSF (Grant No. DMR-1306101) for financial support. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. ; Approved Most recent IF: 2.068  
  Call Number UA @ lucian @ c:irua:137132 Serial 4359  
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Author Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. pdf  url
doi  openurl
  Title First-principles study of the optoelectronic properties and photovoltaic absorber layer efficiency of Cu-based chalcogenides Type A1 Journal article
  Year (down) 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 120 Issue 120 Pages 085707  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract Cu-based chalcogenides are promising materials for thin-film solar cells with more than 20% measured

cell efficiency. Using first-principles calculations based on density functional theory, the

optoelectronic properties of a group of Cu-based chalcogenides Cu2-II-IV-VI4 is studied. They are

then screened with the aim of identifying potential absorber materials for photovoltaic applications.

The spectroscopic limited maximum efficiency (SLME) introduced by Yu and Zunger [Phys. Rev.

Lett. 108, 068701 (2012)] is used as a metric for the screening. After constructing the currentvoltage

curve, the SLME is calculated from the maximum power output. The role of the nature of

the band gap, direct or indirect, and also of the absorptivity of the studied materials on the maximum

theoretical power conversion efficiency is studied. Our results show that Cu2II-GeSe4 with

II¼ Cd and Hg, and Cu2-II-SnS4 with II ¼ Cd, Hg, and Zn have a higher theoretical efficiency

compared with the materials currently used as absorber layer.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000383913400074 Publication Date 2016-08-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.068 Times cited 29 Open Access  
  Notes We acknowledge the financial support from the FWO-Vlaanderen through project G.0150.13N and a GOA fund from the University of Antwerp. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), bothfunded by the FWO-Vlaanderen and the Flemish Government–department EWI. Approved Most recent IF: 2.068  
  Call Number c:irua:135089 Serial 4113  
Permanent link to this record
 

 
Author Clima, S.; Chen, Y.Y.; Chen, C.Y.; Goux, L.; Govoreanu, B.; Degraeve, R.; Fantini, A.; Jurczak, M.; Pourtois, G. url  doi
openurl 
  Title First-principles thermodynamics and defect kinetics guidelines for engineering a tailored RRAM device Type A1 Journal article
  Year (down) 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 119 Issue 119 Pages 225107  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Resistive Random Access Memories are among the most promising candidates for the next generation of non-volatile memory. Transition metal oxides such as HfOx and TaOx attracted a lot of attention due to their CMOS compatibility. Furthermore, these materials do not require the inclusion of extrinsic conducting defects since their operation is based on intrinsic ones (oxygen vacancies). Using Density Functional Theory, we evaluated the thermodynamics of the defects formation and the kinetics of diffusion of the conducting species active in transition metal oxide RRAM materials. The gained insights based on the thermodynamics in the Top Electrode, Insulating Matrix and Bottom Electrode and at the interfaces are used to design a proper defect reservoir, which is needed for a low-energy reliable switching device. The defect reservoir has also a direct impact on the retention of the Low Resistance State due to the resulting thermodynamic driving forces. The kinetics of the diffusing conducting defects in the Insulating Matrix determine the switching dynamics and resistance retention. The interface at the Bottom Electrode has a significant impact on the low-current operation and long endurance of the memory cell. Our first-principles findings are confirmed by experimental measurements on fabricated RRAM devices. Published by AIP Publishing.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000378925400035 Publication Date 2016-06-10  
  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 17 Open Access  
  Notes Approved Most recent IF: 2.068  
  Call Number UA @ lucian @ c:irua:134651 Serial 4181  
Permanent link to this record
 

 
Author Van de Put, M.L.; Vandenberghe, W.G.; Sorée, B.; Magnus, W.; Fischetti, M.V. url  doi
openurl 
  Title Inter-ribbon tunneling in graphene: An atomistic Bardeen approach Type A1 Journal article
  Year (down) 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 119 Issue 119 Pages 214306  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract A weakly coupled system of two crossed graphene nanoribbons exhibits direct tunneling due to the overlap of the wavefunctions of both ribbons. We apply the Bardeen transfer Hamiltonian formalism, using atomistic band structure calculations to account for the effect of the atomic structure on the tunneling process. The strong quantum-size confinement of the nanoribbons is mirrored by the one-dimensional character of the electronic structure, resulting in properties that differ significantly from the case of inter-layer tunneling, where tunneling occurs between bulk two-dimensional graphene sheets. The current-voltage characteristics of the inter-ribbon tunneling structures exhibit resonance, as well as stepwise increases in current. Both features are caused by the energetic alignment of one-dimensional peaks in the density-of-states of the ribbons. Resonant tunneling occurs if the sign of the curvature of the coupled energy bands is equal, whereas a step-like increase in the current occurs if the signs are opposite. Changing the doping modulates the onset-voltage of the effects as well as their magnitude. Doping through electrostatic gating makes these structures promising for application towards steep slope switching devices. Using the atomistic empirical pseudopotentials based Bardeen transfer Hamiltonian method, inter-ribbon tunneling can be studied for the whole range of two-dimensional materials, such as transition metal dichalcogenides. The effects of resonance and of step-like increases in the current we observe in graphene ribbons are also expected in ribbons made from these alternative two-dimensional materials, because these effects are manifestations of the one-dimensional character of the density-of-states. Published by AIP Publishing.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000378923100022 Publication Date 2016-06-07  
  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 6 Open Access  
  Notes ; ; Approved Most recent IF: 2.068  
  Call Number UA @ lucian @ c:irua:134652 Serial 4198  
Permanent link to this record
 

 
Author Andrikopoulos, D.; Sorée, B.; De Boeck, J. url  doi
openurl 
  Title Skyrmion-induced bound states on the surface of three-dimensional topological insulators Type A1 Journal article
  Year (down) 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 119 Issue 119 Pages 193903  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The interaction between the surface of a 3D topological insulator and a skyrmion/anti-skyrmion structure is studied in order to investigate the possibility of electron confinement due to the skyrmion presence. Both hedgehog (Neel) and vortex (Bloch) skyrmions are considered. For the hedgehog skyrmion, the in-plane components cannot be disregarded and their interaction with the surface state of the topological insulator (TI) has to be taken into account. A semi-classical description of the skyrmion chiral angle is obtained using the variational principle. It is shown that both the hedgehog and the vortex skyrmion can induce bound states on the surface of the TI. However, the number and the properties of these states depend strongly on the skyrmion type and the skyrmion topological number N-Sk. The probability densities of the bound electrons are also derived where it is shown that they are localized within the skyrmion region. Published by AIP Publishing.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000377718100013 Publication Date 2016-05-18  
  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 8 Open Access  
  Notes ; ; Approved Most recent IF: 2.068  
  Call Number UA @ lucian @ c:irua:134607 Serial 4244  
Permanent link to this record
 

 
Author De Schutter, B.; Van Stiphout, K.; Santos, N.M.; Bladt, E.; Jordan-Sweet, J.; Bals, S.; Lavoie, C.; Comrie, C.M.; Vantomme, A.; Detavernier, C. pdf  url
doi  openurl
  Title Phase formation and texture of thin nickel germanides on Ge(001) and Ge(111) Type A1 Journal article
  Year (down) 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 119 Issue 119 Pages 135305  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We studied the solid-phase reaction between a thin Nifilm and a single crystal Ge(001) or Ge(111) substrate during a ramp anneal. The phase formation sequence was determined using in situX-ray diffraction and in situRutherford backscattering spectrometry (RBS), while the nature and the texture of the phases were studied using X-ray pole figures and transmission electron microscopy. The phase sequence is characterized by the formation of a single transient phase before NiGe forms as the final and stable phase. X-ray pole figures were used to unambiguously identify the transient phase as the ϵ-phase, a non-stoichiometric Ni-rich germanide with a hexagonal crystal structure that can exist for Ge concentrations between 34% and 48% and which forms with a different epitaxial texture on both substrate orientations. The complementary information gained from both RBS and X-ray pole figure measurements revealed a simultaneous growth of both the ϵ-phase and NiGe over a small temperature window on both substrate orientations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000374150200035 Publication Date 2016-04-05  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.068 Times cited 14 Open Access OpenAccess  
  Notes The authors thank the FWO-vlaanderen, BOF-UGent (under Contract No. “GOA 01G01513”) and the Hercules Foundation (under Project No. “AUGE/09/014”) for financial support. S. Bals acknowledges financial support from European Research Council (ERC Starting Grant No. “#335078-COLOURATOMS”). A. Vantomme thanks the BOF-KULeuven (under Contract No. “GOA/14/007”) and the Joint Science and Technology Collaboration between the FWO (G.0031.14) and NRF (UID88013). The National Synchrotron Light Source (NSLS), Brookhaven National Laboratory, was supported by the U.S. Department of Energy, Office of Basic Energy Sciences (Contract No. DE-AC02-98CH10886).; ECAS_Sara; (ROMEO:green; preprint:; postprint:can ; pdfversion:restricted); Approved Most recent IF: 2.068  
  Call Number c:irua:132897 Serial 4066  
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Author Frota, D.A.; Chaves, A.; Ferreira, W.P.; Farias, G.A.; Milošević, M.V. doi  openurl
  Title Superconductor-ferromagnet bilayer under external drive : the role of vortex-antivortex matter Type A1 Journal article
  Year (down) 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 119 Issue 119 Pages 093912  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Using advanced Ginzburg-Landau simulations, we study the superconducting state of a thin superconducting film under a ferromagnetic layer, separated by an insulating oxide, in applied external magnetic field and electric current. The taken uniaxial ferromagnet is organized into a series of parallel domains with alternating polarization of out-of-plane magnetization, sufficiently strong to induce vortex-antivortex pairs in the underlying superconductor in absence of other magnetic field. We show the organization of such vortex-antivortex matter into rich configurations, some of which are not matching the periodicity of the ferromagnetic film. The variety of possible configurations is enhanced by applied homogeneous magnetic field, where additional vortices in the superconductor may lower the energy of the system by either annihilating the present antivortices under negative ferromagnetic domains or by lowering their own energy after positioning under positive ferromagnetic domains. As a consequence, both the vortex-antivortex reordering in increasing external field and the evolution of the energy of the system are highly nontrivial. Finally, we reveal the very interesting effects of applied dc electric current on the vortex-antivortex configurations, since resulting Lorentzian force has opposite direction for vortices and antivortices, while direction of the applied current with respect to ferromagnetic domains is of crucial importance for the interaction of the applied and the Meissner current, as well as the consequent vortex-antivortex dynamics-both of which are reflected in the anisotropic critical current of the system. (C) 2016 AIP Publishing LLC.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000372351900018 Publication Date 2016-03-07  
  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 4 Open Access  
  Notes ; This work was supported by the Brazilian agencies CNPq, PRONEX/FUNCAP, and CAPES, and the Research Foundation-Flanders (FWO). ; Approved Most recent IF: 2.068  
  Call Number UA @ lucian @ c:irua:133200 Serial 4255  
Permanent link to this record
 

 
Author Torun, E.; Sahin, H.; Cahangirov, S.; Rubio, A.; Peeters, F.M. url  doi
openurl 
  Title Anisotropic electronic, mechanical, and optical properties of monolayer WTe2 Type A1 Journal article
  Year (down) 2016 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 119 Issue 7 Pages 074307  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Using first-principles calculations, we investigate the electronic, mechanical, and optical properties of monolayer WTe2. Atomic structure and ground state properties of monolayer WTe2 (T-d phase) are anisotropic which are in contrast to similar monolayer crystals of transition metal dichalcogenides, such as MoS2, WS2, MoSe2, WSe2, and MoTe2, which crystallize in the H-phase. We find that the Poisson ratio and the in-plane stiffness is direction dependent due to the symmetry breaking induced by the dimerization of the W atoms along one of the lattice directions of the compound. Since the semimetallic behavior of the T-d phase originates from this W-W interaction (along the a crystallographic direction), tensile strain along the dimer direction leads to a semimetal to semiconductor transition after 1% strain. By solving the Bethe-Salpeter equation on top of single shot G(0)W(0) calculations, we predict that the absorption spectrum of T-d-WTe2 monolayer is strongly direction dependent and tunable by tensile strain. (C) 2016 AIP Publishing LLC.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000375158000022 Publication Date 2016-02-19  
  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 62 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-V1) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. was supported by a FWO Pegasus Long Marie Curie Fellowship. S.C. and A.R. acknowledge the financial support from the Marie Curie grant FP7-PEOPLE-2013-IEF Project No. 628876, European Research Council (ERC-2010-AdG-267374), Spanish grant (FIS2013-46159-C3-1-P), Grupos Consolidados (IT578-13), and AFOSR Grant No. FA2386-15-1-0006 AOARD 144088, H2020-NMP-2014 project MOSTOPHOS, GA No. SEP-210187476, and COST Action MP1306 (EUSpec). S.C. acknowledges the support from The Scientific and Technological Research Council of Turkey (TUBITAK) under Project No. 115F388. ; Approved Most recent IF: 2.068  
  Call Number UA @ lucian @ c:irua:144747 Serial 4640  
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Author de Sousa, A.A.; Chaves, A.; Pereira, T.A.S.; Farias, G.A.; Peeters, F.M. doi  openurl
  Title Quantum tunneling between bent semiconductor nanowires Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 118 Issue 118 Pages 174301  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We theoretically investigate the electronic transport properties of two closely spaced L-shaped semiconductor quantum wires, for different configurations of the output channel widths as well as the distance between the wires. Within the effective-mass approximation, we solve the time-dependent Schrodinger equation using the split-operator technique that allows us to calculate the transmission probability, the total probability current, the conductance, and the wave function scattering between the energy subbands. We determine the maximum distance between the quantum wires below which a relevant non-zero transmission is still found. The transmission probability and the conductance show a strong dependence on the width of the output channel for small distances between the wires. (C) 2015 AIP Publishing LLC.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000364584200020 Publication Date 2015-11-02  
  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 7 Open Access  
  Notes ; A. A. Sousa was financially supported by CAPES, under the PDSE Contract No. BEX 7177/13-5. T. A. S. Pereira was financially supported by PRONEX/CNPq/FAPEMAT 850109/2009 and by CAPES under process BEX 3299/13-9. This work was financially supported by PRONEX/CNPq/FUNCAP, the Science Without Borders program and the bilateral project CNPq-FWO. ; Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number UA @ lucian @ c:irua:129544 Serial 4234  
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Author Milovanović, S.P.; Moldovan, D.; Peeters, F.M. pdf  url
doi  openurl
  Title Veselago lensing in graphene with a p-n junction: Classical versus quantum effects Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 118 Issue 118 Pages 154308  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The feasibility of Veselago lensing in graphene with a p-n junction is investigated numerically for realistic injection leads. Two different set-ups with two narrow leads are considered with absorbing or reflecting side edges. This allows us to separately determine the influence of scattering on electron focusing for the edges and the p-n interface. Both semiclassical and tight-binding simulations show a distinctive peak in the transmission probability that is attributed to the Veselago lensing effect. We investigate the robustness of this peak on the width of the injector, the position of the p-n interface, and different gate potential profiles. Furthermore, the influence of scattering by both short- and long-range impurities is considered.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000363535800022 Publication Date 2015-10-20  
  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 19 Open Access  
  Notes This work was supported by the Flemish Science Foundation (FWO-Vl), the European Science Foundation (ESF) under the EUROCORES Program EuroGRAPHENE within the project CONGRAN, and the Methusalem Foundation of the Flemish government. Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number c:irua:129452 Serial 3969  
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Author Verreck, D.; Verhulst, A.S.; Van de Put, M.; Sorée, B.; Magnus, W.; Mocuta, A.; Collaert, N.; Thean, A.; Groeseneken, G. doi  openurl
  Title Full-zone spectral envelope function formalism for the optimization of line and point tunnel field-effect transistors Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 118 Issue 118 Pages 134502  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Efficient quantum mechanical simulation of tunnel field-effect transistors (TFETs) is indispensable to allow for an optimal configuration identification. We therefore present a full-zone 15-band quantum mechanical solver based on the envelope function formalism and employing a spectral method to reduce computational complexity and handle spurious solutions. We demonstrate the versatility of the solver by simulating a 40 nm wide In0.53Ga0.47As lineTFET and comparing it to p-n-i-n configurations with various pocket and body thicknesses. We find that the lineTFET performance is not degraded compared to semi-classical simulations. Furthermore, we show that a suitably optimized p-n-i-n TFET can obtain similar performance to the lineTFET. (C) 2015 AIP Publishing LLC.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000362668400025 Publication Date 2015-10-01  
  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 9 Open Access  
  Notes ; D. Verreck acknowledges the support of a Ph.D. stipend from the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). This work was supported by imec's Industrial Affiliation Program. ; Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number UA @ lucian @ c:irua:128765 Serial 4183  
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Author Moors, K.; Sorée, B.; Magnus, W. url  doi
openurl 
  Title Modeling surface roughness scattering in metallic nanowires Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 118 Issue 118 Pages 124307  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Ando's model provides a rigorous quantum-mechanical framework for electron-surface roughness scattering, based on the detailed roughness structure. We apply this method to metallic nanowires and improve the model introducing surface roughness distribution functions on a finite domain with analytical expressions for the average surface roughness matrix elements. This approach is valid for any roughness size and extends beyond the commonly used Prange-Nee approximation. The resistivity scaling is obtained from the self-consistent relaxation time solution of the Boltzmann transport equation and is compared to Prange-Nee's approach and other known methods. The results show that a substantial drop in resistivity can be obtained for certain diameters by achieving a large momentum gap between Fermi level states with positive and negative momentum in the transport direction. (C) 2015 AIP Publishing LLC.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000362565800032 Publication Date 2015-09-24  
  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 11 Open Access  
  Notes ; ; Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number UA @ lucian @ c:irua:129425 Serial 4207  
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Author Schoeters, B.; Leenaerts, O.; Pourtois, G.; Partoens, B. pdf  url
doi  openurl
  Title Ab-initio study of the segregation and electronic properties of neutral and charged B and P dopants in Si and Si/SiO2 nanowires Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 118 Issue 118 Pages 104306  
  Keywords A1 Journal article; Condensed Matter Theory (CMT); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract We perform first-principles calculations to investigate the preferred positions of B and P dopants, both neutral and in their preferred charge state, in Si and Si/SiO2 core-shell nanowires (NWs). In order to understand the observed trends in the formation energy, we isolate the different effects that determine these formation energies. By making the distinction between the unrelaxed and the relaxed formation energy, we separate the impact of the relaxation from that of the chemical environment. The unrelaxed formation energies are determined by three effects: (i) the effect of strain caused by size mismatch between the dopant and the host atoms, (ii) the local position of the band edges, and (iii) a screening effect. In the case of the SiNW (Si/SiO2 NW), these effects result in an increase of the formation energy away from the center (interface). The effect of relaxation depends on the relative size mismatch between the dopant and host atoms. A large size mismatch causes substantial relaxation that reduces the formation energy considerably, with the relaxation being more pronounced towards the edge of the wires. These effects explain the surface segregation of the B dopants in a SiNW, since the atomic relaxation induces a continuous drop of the formation energy towards the edge. However, for the P dopants, the formation energy starts to rise when moving from the center but drops to a minimum just next to the surface, indicating a different type of behavior. It also explains that the preferential location for B dopants in Si/SiO2 core-shell NWs is inside the oxide shell just next to the interface, whereas the P dopants prefer the positions next to the interface inside the Si core, which is in agreement with recent experiments. These preferred locations have an important impact on the electronic properties of these core-shell NWs. Our simulations indicate the possibility of hole gas formation when B segregates into the oxide shell.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000361636900031 Publication Date 2015-09-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.068 Times cited 3 Open Access  
  Notes 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: 2.068; 2015 IF: 2.183  
  Call Number c:irua:128729 Serial 4056  
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Author Yagmurcukardes, M.; Sahin, H.; Kang, J.; Torun, E.; Peeters, F.M.; Senger, R.T. doi  openurl
  Title Pentagonal monolayer crystals of carbon, boron nitride, and silver azide Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 118 Issue 118 Pages 104303  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract In this study, we present a theoretical investigation of structural, electronic, and mechanical properties of pentagonal monolayers of carbon (p-graphene), boron nitride (p-B2N4 and p-B4N2), and silver azide (p-AgN3) by performing state-of-the-art first principles calculations. Our total energy calculations suggest feasible formation of monolayer crystal structures composed entirely of pentagons. In addition, electronic band dispersion calculations indicate that while p-graphene and p-AgN3 are semiconductors with indirect bandgaps, p-BN structures display metallic behavior. We also investigate the mechanical properties (in-plane stiffness and the Poisson's ratio) of four different pentagonal structures under uniaxial strain. p-graphene is found to have the highest stiffness value and the corresponding Poisson's ratio is found to be negative. Similarly, p-B2N4 and p-B4N2 have negative Poisson's ratio values. On the other hand, the p-AgN3 has a large and positive Poisson's ratio. In dynamical stability tests based on calculated phonon spectra of these pentagonal monolayers, we find that only p-graphene and p-B2N4 are stable, but p-AgN3 and p-B4N2 are vulnerable against vibrational excitations.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000361636900028 Publication Date 2015-09-08  
  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 79 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. was supported by a FWO Pegasus Long Marie Curie Fellowship. H.S. and R.T.S. acknowledge the support from TUBITAK through Project No. 114F397. ; Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number UA @ lucian @ c:irua:128415 Serial 4223  
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Author Zhao, S.-X.; Gao, F.; Wang, Y.-P.; Wang, Y.-N.; Bogaerts, A. pdf  url
doi  openurl
  Title Effects of feedstock availability on the negative ion behavior in a C4F8 inductively coupled plasma Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 118 Issue 118 Pages 033301  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract In this paper, the negative ion behavior in a C4F8 inductively coupled plasma (ICP) is investigated using a hybrid model. The model predicts a non-monotonic variation of the total negative ion density with power at low pressure (1030 mTorr), and this trend agrees well with experiments that were carried out in many fluorocarbon (fc) ICP sources, like C2F6, CHF3, and C4F8. This behavior is explained by the availability of feedstock C4F8 gas as a source of the negative ions, as well as by the presence of low energy electrons due to vibrational excitation at low power. The maximum of the negative ion density shifts to low power values upon decreasing pressure, because of the more pronounced depletion of C4F8 molecules, and at high pressure (∼50 mTorr), the anion density continuously increases with power, which is similar to fc CCP sources. Furthermore, the negative ion composition is identified in this paper. Our work demonstrates that for a clear understanding of the negative ion behavior in radio frequency C4F8 plasma sources, one needs to take into account many factors, like the attachment characteristics, the anion composition, the spatial profiles, and the reactor configuration. Finally, a detailed comparison of our simulation results with experiments is conducted.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000358429200004 Publication Date 2015-07-20  
  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 1 Open Access  
  Notes Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number c:irua:126735 Serial 861  
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Author Berdiyorov, G.; Harrabi, K.; Mehmood, U.; Peeters, F.M.; Tabet, N.; Zhang, J.; Hussein, I.A.; McLachlan, M.A. doi  openurl
  Title Derivatization and diffusive motion of molecular fullerenes : ab initio and atomistic simulations Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 118 Issue 118 Pages 025101  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Using first principles density functional theory in combination with the nonequilibrium Green's function formalism, we study the effect of derivatization on the electronic and transport properties of C-60 fullerene. As a typical example, we consider [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM), which forms one of the most efficient organic photovoltaic materials in combination with electron donating polymers. Extra peaks are observed in the density of states (DOS) due to the formation of new electronic states localized at/near the attached molecule. Despite such peculiar behavior in the DOS of an isolated molecule, derivatization does not have a pronounced effect on the electronic transport properties of the fullerene molecular junctions. Both C-60 and PCBM show the same response to finite voltage biasing with new features in the transmission spectrum due to voltage induced delocalization of some electronic states. We also study the diffusive motion of molecular fullerenes in ethanol solvent and inside poly(3-hexylthiophene) lamella using reactive molecular dynamics simulations. We found that the mobility of the fullerene reduces considerably due to derivatization; the diffusion coefficient of C-60 is an order of magnitude larger than the one for PCBM. (c) 2015 AIP Publishing LLC.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000357961000036 Publication Date 2015-07-10  
  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 2 Open Access  
  Notes ; K.H., U.M. and I.A.H. would like to thank the National Science, Technology and Innovation Program of KACST for funding this research under Project No. 12-ENE2379-04. They also acknowledge support from KFUPM and Research Institute. ; Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number c:irua:127098 Serial 652  
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Author Zhao, S.-X.; Zhang, Y.-R.; Gao, F.; Wang, Y.-N.; Bogaerts, A. url  doi
openurl 
  Title Bulk plasma fragmentation in a C4F8 inductively coupled plasma : a hybrid modelling study Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 117 Issue 117 Pages 243303  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract A hybrid model is used to investigate the fragmentation of C4F8 inductive discharges. Indeed, the resulting reactive species are crucial for the optimization of the Si-based etching process, since they determine the mechanisms of fluorination, polymerization, and sputtering. In this paper, we present the dissociation degree, the density ratio of F vs. CxFy (i.e., fluorocarbon (fc) neutrals), the neutral vs. positive ion density ratio, details on the neutral and ion components, and fractions of various fc neutrals (or ions) in the total fc neutral (or ion) density in a C4F8 inductively coupled plasma source, as well as the effect of pressure and power on these results. To analyze the fragmentation behavior, the electron density and temperature and electron energy probability function (EEPF) are investigated. Moreover, the main electron-impact generation sources for all considered neutrals and ions are determined from the complicated C4F8 reaction set used in the model. The C4F8 plasma fragmentation is explained, taking into account many factors, such as the EEPF characteristics, the dominance of primary and secondary processes, and the thresholds of dissociation and ionization. The simulation results are compared with experiments from literature, and reasonable agreement is obtained. Some discrepancies are observed, which can probably be attributed to the simplified polymer surface kinetics assumed in the model.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000357613900009 Publication Date 2015-06-30  
  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 11 Open Access  
  Notes Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number c:irua:126477 Serial 261  
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Author Zhao, C.X.; Xu, W.; Li, L.L.; Zhang, C.; Peeters, F.M. doi  openurl
  Title Terahertz plasmon-polariton modes in graphene driven by electric field inside a Fabry-Perot cavity Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 117 Issue 117 Pages 223104  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We present a theoretical study on plasmon-polariton modes in graphene placed inside an optical cavity and driven by a source-to-drain electric field. The electron velocity and electron temperature are determined by solving self-consistently the momentum-and energy-balance equations in which electron interactions with impurities, acoustic-, and optic-phonons are included. Based on many-body self-consistent field theory, we develop a tractable approach to study plasmon-polariton in an electron gas system. We find that when graphene is placed inside a Fabry-Perot cavity, two branches of the plasmon-polariton modes can be observed and these modes are very much optic-or plasmon-like. The frequencies of these modes depend markedly on driving electric field especially at higher resonant frequency regime. Moreover, the plasmon-polariton frequency in graphene is in terahertz (THz) bandwidth and can be tuned by changing the cavity length, gate voltage, and driving electric field. This work is pertinent to the application of graphene-based structures as tunable THz plasmonic devices. (C) 2015 AIP Publishing LLC.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000356176100004 Publication Date 2015-06-10  
  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 13 Open Access  
  Notes ; This work was supported by the Ministry of Science and Technology of China (Grant No. 2011YQ130018), Department of Science and Technology of Yunnan Province, and by the Chinese Academy of Sciences. F.M.P. was a specially appointed Professor for foreign expert at the Chinese Academy of Sciences. ; Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number c:irua:127076 Serial 3507  
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Author Berdiyorov, G.R.; Bahlouli, H.; Peeters, F.M. url  doi
openurl 
  Title Theoretical study of electronic transport properties of a graphene-silicene bilayer Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 117 Issue 117 Pages 225101  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Electronic transport properties of a graphene-silicene bilayer system are studied using density-functional theory in combination with the nonequilibrium Green's function formalism. Depending on the energy of the electrons, the transmission can be larger in this system as compared to the sum of the transmissions of separated graphene and silicene monolayers. This effect is related to the increased electron density of states in the bilayer sample. At some energies, the electronic states become localized in one of the layers, resulting in the suppression of the electron transmission. The effect of an applied voltage on the transmission becomes more pronounced in the layered sample as compared to graphene due to the larger variation of the electrostatic potential profile. Our findings will be useful when creating hybrid nanoscale devices where enhanced transport properties will be desirable. (C) 2015 AIP Publishing LLC.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000356176100040 Publication Date 2015-06-10  
  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 10 Open Access  
  Notes ; H. B. and F. M. P. acknowledge support from King Fahd University of Petroleum and Minerals, Saudi Arabia, under the RG1329-1 and RG1329-2 DSR Projects. ; Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number c:irua:127075 Serial 3611  
Permanent link to this record
 

 
Author Li, L.L.; Xu, W.; Peeters, F.M. doi  openurl
  Title Optical conductivity of topological insulator thin films Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 117 Issue 117 Pages 175305  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We present a detailed theoretical study on the optoelectronic properties of topological insulator thin film (TITFs). The k . p approach is employed to calculate the energy spectra and wave functions for both the bulk and surface states in the TITF. With these obtained results, the optical conductivities induced by different electronic transitions among the bulk and surface states are evaluated using the energy-balance equation derived from the Boltzmann equation. We find that for Bi2Se3-based TITFs, three characteristic regimes for the optical absorption can be observed. (i) In the low radiation frequency regime (photon energy (h) over bar omega < 200 meV), the free-carrier absorption takes place due to intraband electronic transitions. An optical absorption window can be observed. (ii) In the intermediate radiation frequency regime (200 < (h) over bar omega < 300 meV), the optical absorption is induced mainly by interband electronic transitions from surface states in the valance band to surface states in the conduction band and an universal value sigma(0) = e(2) / (8<(h)over bar>) for the optical conductivity can be obtained. (iii) In the high radiation frequency regime ((h) over bar omega > 300 meV), the optical absorption can be achieved via interband electronic transitions from bulk and surface states in the valance band to bulk and surface states in the conduction band. A strong absorption peak can be observed. These interesting findings indicate that optical measurements can be applied to identify the energy regimes of bulk and surface states in the TITF. (C) 2015 AIP Publishing LLC.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000354984100615 Publication Date 2015-05-06  
  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 9 Open Access  
  Notes ; This work was supported by the National Natural Science Foundation of China (Grant No. 11304316), Ministry of Science and Technology of China (Grant No. 2011YQ130018), Department of Science and Technology of Yunnan Province, and by the Chinese Academy of Sciences. ; Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number c:irua:126412 Serial 2473  
Permanent link to this record
 

 
Author Bekaert, J.; Saniz, R.; Partoens, B.; Lamoen, D. pdf  url
doi  openurl
  Title First-principles study of carbon impurities in CuInSe2 and CuGaSe2, present in non-vacuum synthesis methods Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 117 Issue 117 Pages 015104  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract A first-principles study of the structural and electronic properties of carbon impurities in CuInSe2 and CuGaSe2 is presented. Carbon is present in organic molecules in the precursor solutions used in non-vacuum growth methods for CuInSe2 and CuGaSe2 based photovoltaic cells. These growth methods make more efficient use of material, time, and energy than traditional vacuum methods. The formation energies of several carbon impurities are calculated using the hybrid HSE06 functional. C Cu acts as a shallow donor, CIn and interstitial C yield deep donor levels in CuInSe2, while in CuGaSe2 CGa and interstitial C act as deep amphoteric defects. So, these defects reduce the majority carrier (hole) concentration in p-type CuInSe2 and CuGaSe2 by compensating the acceptor levels. The deep defects are likely to act as recombination centers for the photogenerated charge carriers and are thus detrimental for the performance of the photovoltaic cells. On the other hand, the formation energies of the carbon impurities are high, even under C-rich growth conditions. Thus, few C impurities will form in CuInSe2 and CuGaSe2 in thermodynamic equilibrium. However, the deposition of the precursor solution in non-vacuum growth methods presents conditions far from thermodynamic equilibrium. In this case, our calculations show that C impurities formed in non-equilibrium tend to segregate from CuInSe2 and CuGaSe2 by approaching thermodynamic equilibrium, e.g., via thorough annealing.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000347958600055 Publication Date 2015-01-07  
  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 6 Open Access  
  Notes FWO G015013; Hercules Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number c:irua:122064 Serial 1215  
Permanent link to this record
 

 
Author Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D. url  doi
openurl 
  Title Ab initio study of shallow acceptors in bixbyite V2O3 Type A1 Journal article
  Year (down) 2015 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 117 Issue 117 Pages 015703  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract We present the results of our study on p-type dopability of bixbyite V2O3 using the Heyd, Scuseria, and Ernzerhof hybrid functional (HSE06) within the density functional theory (DFT) formalism. We study vanadium and oxygen vacancies as intrinsic defects and substitutional Mg, Sc, and Y as extrinsic defects. We find that Mg substituting V acts as a shallow acceptor, and that oxygen vacancies are electrically neutral. Hence, we predict Mg-doped V2O3 to be a p-type conductor. Our results also show that vanadium vacancies are relatively shallow, with a binding energy of 0.14 eV, so that they might also lead to p-type conductivity.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000347958600067 Publication Date 2015-01-05  
  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 3 Open Access  
  Notes FWO G015013; Hercules Approved Most recent IF: 2.068; 2015 IF: 2.183  
  Call Number c:irua:122728 Serial 35  
Permanent link to this record
 

 
Author Sen, H.S.; Sahin, H.; Peeters, F.M.; Durgun, E. doi  openurl
  Title Monolayers of MoS2 as an oxidation protective nanocoating material Type A1 Journal article
  Year (down) 2014 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 116 Issue 8 Pages 083508  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract First-principle calculations are employed to investigate the interaction of oxygen with ideal and defective MoS2 monolayers. Our calculations show that while oxygen atoms are strongly bound on top of sulfur atoms, the oxygen molecule only weakly interacts with the surface. The penetration of oxygen atoms and molecules through a defect-free MoS2 monolayer is prevented by a very high diffusion barrier indicating that MoS2 can serve as a protective layer for oxidation. The analysis is extended to WS2 and similar coating characteristics are obtained. Our calculations indicate that ideal and continuous MoS2 and WS2 monolayers can improve the oxidation and corrosion-resistance of the covered surface and can be considered as an efficient nanocoating material. (C) 2014 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000342821600017 Publication Date 2014-08-27  
  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 52 Open Access  
  Notes ; This work was supported by the bilateral project between TUBITAK (through Grant No. 113T050) and Flemish Science Foundation (FWO-Vl). The calculations were performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). E.D. acknowledges support from Bilim Akademisi-The Science Academy, Turkey under the BAGEP program. H.S. is supported by an FWO Pegasus-long Marie Curie Fellowship. ; Approved Most recent IF: 2.068; 2014 IF: 2.183  
  Call Number UA @ lucian @ c:irua:121101 Serial 2194  
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Author Moors, K.; Sorée, B.; Tokei, Z.; Magnus, W. url  doi
openurl 
  Title Resistivity scaling and electron relaxation times in metallic nanowires Type A1 Journal article
  Year (down) 2014 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 116 Issue 6 Pages 063714  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We study the resistivity scaling in nanometer-sized metallic wires due to surface roughness and grain-boundaries, currently the main cause of electron scattering in nanoscaled interconnects. The resistivity has been obtained with the Boltzmann transport equation, adopting the relaxation time approximation of the distribution function and the effective mass approximation for the conducting electrons. The relaxation times are calculated exactly, using Fermi's golden rule, resulting in a correct relaxation time for every sub-band state contributing to the transport. In general, the relaxation time strongly depends on the sub-band state, something that remained unclear with the methods of previous work. The resistivity scaling is obtained for different roughness and grain-boundary properties, showing large differences in scaling behavior and relaxation times. Our model clearly indicates that the resistivity is dominated by grain-boundary scattering, easily surpassing the surface roughness contribution by a factor of 10. (C) 2014 AIP Publishing LLC.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000341179400036 Publication Date 2014-08-15  
  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 17 Open Access  
  Notes ; ; Approved Most recent IF: 2.068; 2014 IF: 2.183  
  Call Number UA @ lucian @ c:irua:119260 Serial 2882  
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Author Wen, D.-Q.; Zhang, Q.-Z.; Jiang, W.; Song, U.-H.; Bogaerts, A.; Wang, Y.-N. pdf  doi
openurl 
  Title Phase modulation in pulsed dual-frequency capacitively coupled plasmas Type A1 Journal article
  Year (down) 2014 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 115 Issue 23 Pages 233303  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract Particle-in-cell/Monte Carlo collision simulations, coupled with an external circuit, are used to investigate the behavior of pulsed dual-frequency (DF) capacitively coupled plasmas (CCPs). It is found that the phase shift θ between the high (or low) frequency source and the pulse modulation has a great influence on the ion density and the ionization rate. By pulsing the high frequency source, the time-averaged ion density shows a maximum when θ = 90∘. The time-averaged ion energy distribution functions (IEDFs) at the driven electrode, however, keep almost unchanged, illustrating the potential of pulsed DF-CCP for independent control of ion density (and flux) and ion energy. A detailed investigation of the temporal evolution of the plasma characteristics indicates that several high frequency harmonics can be excited at the initial stage of a pulse period by tuning the phase shift θ, and this gives rise to strong sheath oscillations, and therefore high ionization rates. For comparison, the pulsing of the low frequency source is also studied. In this case, the ion density changes slightly as a function of time, and the time-averaged ion density shows the same trend as in the HF modulation for different phase shifts θ. Moreover, the time-averaged IEDFs at the driven electrode can be modulated, showing the potential to reduce the maximum ion bombardment energy.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000338106000008 Publication Date 2014-06-23  
  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 8 Open Access  
  Notes Approved Most recent IF: 2.068; 2014 IF: 2.183  
  Call Number UA @ lucian @ c:irua:117415 Serial 2585  
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