ODD numbers present in session A (wednesday). EVEN numbers present in session B (thursday) The posters should be up throughout the duration of the meeting. The recommended poster format is A0 (landscape or portrait).
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Poster abstracts 2017
Gaetano Calogero: Atomistic large-scale simulations of transport in ballistic graphene
Gaetano Calogero , Nick P. Rübner, Peter Bøggild, Mads Brandbyge Danish Technical University (DTU Nanotech), Center for Nanostructured Graphene.DK-2800 Kgs. Lyngby, Denmark Graphene exhibits astonishing mesoscopic effects hosting massless Dirac quasiparticles that can travel with little scattering and behave like light rays. Mean free paths of up to 28 mm have been reached at low temperature [1], while ballistic transport in the micrometre scale has become accessible even at room temperature. Electrons in such devices undergo negative refraction when passing p-n junctions and can be manipulated by external electromagnetic fields, paving the way to a new concept of electronics based on the principles of optics [2]. One interesting perspective is a “2D Dirac fermion microscope” (DFM), where electron guns, tunable lenses, deflectors, and detectors are combined in a graphene “vacuum chamber” to image different types of targets [3]. We aim at performing multi-scale simulations of ballistic graphene devices starting from atoms, combining density functional theory (DFT) and large-scale tight-binding (TB) models in a non-equilibrium Green’s functions (NEGF) framework. As an application, we use a NEGF+TB model to reproduce key features of electron transport in a DFM, such as electron beam collimation, deflection and scattering off circular p-n junctions. For targets with size larger than the Fermi wavelength (mesoscopic limit), our results resemble those of semiclassical simulations, but quantum coherence leads to a richer emission and reflection structure which may be utilized to extract more detailed information. 1. Banszerus et al. Nano Letters 16, 1387 (2016) 2. Chen et al. Science 353, 1522 (2016) 3. Bøggild et al. Nature Communications 8, 15783 (2017) Gaetano Calogero is currently a PhD student at the Danish Technical University (DTU), in the Theoretical Nanoelectronics group led by Prof. M. Brandbyge. He is primarily interested in theory and multi-scale atomistic simulations of ballistic graphene nanoelectronics. He received his B.S. degree in Physics from University of Catania (IT) in 2013, with a thesis on the role of basis sets on the unfolding of supercell bandstructures. He got his M.S. degree in Physics from the same university (2015), after spending a research period of 5 months as Erasmus+ student at the Debye Institute of Utrecht University (NL), where he worked on density functional theory simulations of atomic force microscopy of nitrogen-doped graphene. |
Razieh Sahraei: Novel magnetic poly(vinyl alcohol)/modified gum tragacanth/graphene oxide hydrogel beads with daul activity for removal of cationic and anionic dyes from water
Razieh Sahraei, Mousa Ghaemy Polymer Research Laboratory, Department of Chemistry, University of Mazandaran, Babolsar, Iran The objective of this work is the preparation of effective magnetic biosorbent beads with the high surface area from a low-value abundant biopolymer (Katira, GT) and graphene oxide (GO) for the removal of dyes from the water. For this aim, magnetic hydrogel beads based on poly(vinyl alcohol)/poly(2-Acrylamido-2-methyl-1-propanesulfonic acid-co-1-vinyl imidazole)-g-gum tragacanth/graphene oxide were prepared by instantaneous gelation method in boric acid solution followed by cross-linking with glutaraldehyde (GA). The prepared magnetic beads with good mechanical stability (97.18%) were used as an effective adsorbent for removal of both cationic (crystal violet, CV) and anionic (congo red, CR) dyes from aqueous solution. The specific surface area and average pore diameter of magnetic beads (with a spherical shape and an average diameter of 3.0 mm) was 283.84 m2/g and 4.2767 ᵒA, respectively. The total pore volume was 0.0303 mL/g and the porosity based on a skeletal density of 0.5 g mL was 0.0149 per gram of sample. The maximum adsorption capacities were found 94.0 and 101.74 mg g-1 for CV and CR, respectively. Therefore, advantages such as biocompatibility, easy preparation and separation, inexpensiveness, chemical stability, high adsorption, reusability, and having functional groups with dual activities make these magnetic beads attractive and broadly applicable in the removal of various pollutants simultaneously from water, wastewater, and for column applications [1-3]. 1.Zhang Y, Liu Y, Wang X, Sun Z, Ma J, Wu T, Xing F, and Gao J, Carbohydr. Polym., 101, 392-400, 2014. 2.Jiang W, Wang W, Pan B, Zhang Q, Zhang W, and Lv L, ACS Appl. Mater. Interfaces, 6(5), 3421-3426, 2014. 3.Pour Z.S, and Ghaemy M, RSC Adv., 5(79), 64106-64118, 2015. |
Sanjoy K. Mahatha: Evidence of out-of-plane metallic band dispersion in commensurate charge density wave of 1T-TaS2
Sanjoy K. Mahatha, Arlette S. Ngankeu, Kevin Guilloy, Marco Bianchi, Charlotte E. Sanders, Kai Rossnagel, Jill Miwa, and Philip Hofmann Department of Physics and Astronomy, Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark The 1T polymorph of layered transition metal dichalcogenide compound TaS2 undergo phase transition towards low temperature with a periodic structural distortion where the electrons organize themselves in regular pattern which is widely known as charge density wave (CDW) [1]. The commensurate CDW phase of 1T-TaS2 has widely been treated as a quasi two-dimensional phenomenon that coexist with a Mott insulating state. However, recent theoretical calculations predicted the coexistence of CDW phase with a nearly one-dimensional metallic dispersion perpendicular to the crystal planes. In this presentation, I will show the angle-resolved photo emission spectroscopy results which confirms the existence of this metallic band [2]. The experimental band width of this metallic band is in excellent agreement with the predicted stacking order of CDW between the adjacent layers and its periodicity along c axis. 1. K. Rossnagel, J. Phys.: Condens. Matter 23, 213001 (2011). 2. Arlette S. Ngankeu, Kevin Guilloy, Sanjoy K. Mahatha, Marco Bianchi, Charlotte E. Sanders, Kai Rossnagel, Jill A. Miwa, and Philip Hofmann, arxiv1705.00455. Sanjoy Kr. Mahatha is currently a Postdoc of Department of Physics and Astronomy at the University of Aarhus. His primary interest lies in studying the growth and electronic structure of two-dimensional Dirac materials and transition metal dichalcogenides. He received his M.Sc. degree in Physics from The University of Burdwan (2006) and a Ph.D. in Experimental Physics (2013) from Calcutta University where he studied the electronic structure of two-dimensional materials and metal overlayers using angle-resolved photoemission. After finishing his Ph.D, he spent little more than 3 years as a postdoctoral researcher in ISM-CNR and in the Elettra Synchrotron, Trieste, Italy studying the electronic structure of silicene and multilayer Si film on Ag(111) and quantization effects in magnetic thin films. His awards include TRIL fellowship awarded by ICTP for carrying out post-doctoral research work at Elettra - Sincrotrone Trieste (2013), MRSI Young Scientist Award (2012) and Best Poster Award in “JSPS-DST Asian Academic Seminar 2010”. |
Aran Garcia-Lekue: Tuning the properties of graphene nanoribbons via chemical modification
Donostia International Physics Center (DIPC), San Sebastian, Spain Ikerbasque, Basque Foundation for Science, Bilbao, Spain UPGRADED TO TALK Armchair Graphene Nanoribbons (AGNRs) are one-dimensional stripes of graphene with a width-dependent electronic bandgap[1], which makes them suitable for applications in carbon-based nanoelectronics. AGNRs can be effectively produced by on-surface reaction of halogenated bianthracene (DBBA) monomers, a synthesis technique providing atomic control on the dimension and edge structure of the ribbons[2]. Furthermore, the electronic structure of the AGNRs can also be tuned by chemical modification of the precursors. Here, we report on the properties of 7-AGNRs periodically doped with boron pairs on Au(111). Our density functional theory (DFT) based findings are compared with scanning tunneling microscopy (STM) and angle-resolved photoemission (ARPES) data. We find that the di-boron backbone reduces the band gap of the nanoribbon, and induces the formation of a new conduction band near the Fermi level. Furthermore, it is possible to grow structures formed by pristine segments separated by regions doped with B pairs. We have studied the properties of such boron defects as scattering centers, and found that they provide large effective barriers for the propagation of electrons in the valence band (VB), but are nearly transparent for the immediately lower energy band (VB-1) due to the different symmetry of both bands. As a result, the VB gives rise to clearly identifiable quantized levels in the pristine regions, with a remarkable agreement between theory and experiment[3]. [1] Son et al., Phys. Rev. Lett. 97, 216803 (2006) [2] Cai et al., Nature 466, 470 (2010) [3] Carbonell-Sanroma et al., Nano Letters 17, 50 (2017) Aran Garcia-Lekue is currently an Ikerbasque Research Fellow at Donostia International Physics Center (DIPC). Her research line is focused on the simulation of electron transport at the nanoscale, and on the theoretical investigation of electron processes at nanostructured surfaces. In the last years, she has been very active in the study of electronic and transport properties of graphenic nanostructures. She received his PhD degree in Physics from the University of the Basque Country UPV/EHU (Spain). After finishing her Ph.D, she held postdoctoral positions at the Surface Science Research Center (SSRC) of the University of Liverpool (UK) and at the Berkeley National Laboratory (US). She joined DIPC as a Gipuzkoa Research Fellow Gipuzkoa in 2007, and became an Ikerbasque Research Fellow in 2012. |
Kristen Kaasbjerg: Symmetry protection against quasiparticle scattering in disordered monolayer transition-metal dichalcogenides
Kristen Kaasbjerg (1), Johannes H. J. Martiny (1), Tony Low (2), and Antti-Pekka Jauho (1) 1) Center for Nanostructured Graphene (CNG), Dept. of Micro- and Nanotechnology, Technical University of Denmark, Denmark 2) Department of Electrical and Computer Engineering, University of Minnesota, USA Here, we demonstrate that besides the spin-valley coupling which partially protects the valley degree of freedom against intervalley scattering as illustrated in Fig. 1, the symmetry and position of atomic disorder give rise to additional selection rules. As shown in Fig. 1, K, K' scattering by disorder with threefold rotational symmetry (C3), e.g., atomic vacancies, is forbidden by symmetry, except in the conduction band for M-centered disorder. We propose to verify our predictions with Fourier transfrom scanning tunneling spectroscopy (FT-STS) which provides direct access to the available scattering channels in q space. For this purpose, we calculate the FT-STS and QPI spectra using an atomistic DFT approach for two archetypal TMDs: the direct gap, small spin-orbit split MoS2, and the indirect gap, large spin-orbit split WSe2. In both cases, the K, K' conduction-band intervalley FT-STS peak is completely absent for X vacancies while appearing clearly for M vacancies, thus suggesting an alternative explanation for its conspicious absence in experiments [1,2]. 1. H. Liu, J. Chen, H. Yu, F. Yang, L. Jiao, G.-B. Liu, W. Ho, C. Gao, J. Jia, W. Yao, and M. Xie, "Observation of intervalley quantum interference in epitaxial monolayer tungsten diselenide," Nature Commun. 6, 8180 (2015). 2. M. Yankowitz, D. McKenzie, and B. J. LeRoy, "Local spectroscopic characterization of spin and layer polarization in WSe2," Phys. Rev. Lett. 115, 136803 (2015). ![]() |
Jack Alexander-Webber: Engineering oxide interfaces for graphene electronics
Department of Engineering, University of Cambridge, United Kingdom ![]() 1. Aria et al. ACS Appl. Mater. Interfaces 8, 30564 (2016) 2. Martin et al. ACS Nano 8, 7890 (2014) 3. Alexander-Webber et al. 2D Materials 4, 011008 (2017) ![]() |
Hyewon Du: The introduction of straightforward fabrication technique to improve device performance at graphene/2D semiconductor junction
Hyewon Du(1), Kunsik An(2), Taekwang Kim(1), Somyeong Shin(1), Seonyeong Kim(1), Minho Song(1), Changhee Lee(2) and Sunae Seo(1) (1) Department of Physics, Sejong University, Seoul, 143-747, South Korea (2) Department of Electrical and Computer Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826 ![]() Here, we introduced Oxidation Scanning Probe Lithography (o-SPL) [3] to integrate multilayer MoS2 transistor with graphene electrode. This technique reduces graphene damage and contamination by minimizing necessary process. With the analysis of AFM, Raman and electrical transport, we could confirm the improved device performance. [1] Yuan Liu, et al. “Van der Waals Heterostructures and Devices” Nat Rev Mater, 1, 16042 (2016) [2] Yuan Liu, et al. “Toward Barrier Free Contact to Molybdenum Disulfide Using Graphene Electrodes” Nano Lett, 15 (5), 3030-3034 (2015) [3] Satoru Masubuchi, et al. “Atomic Force Microscopy Based Tunable Local Anodic Oxidation of Graphene” Nano Lett, 11 (11), 4542-4546 (2011) ![]() |
Nicole Nagy: The Fabrication of Copper-Carbon Nanotube Composites for Global Interconnects
Nicole Nagy, Katharina Lilienthal, Benjamin Uhlig Interconnects, Center Nanoelectronic Technologies (CNT), Fraunhofer Institute for Photonic Microsystems (Fraunhofer IPMS), Dresden ![]() [1] Subramaniam et al. One hundred fold increase in current carrying capacity in a carbon nanotube–copper composite. Nat. Commun. 4:2202 doi: 10.1038/ncomms3202 (2013). [2] Paunovic, M. ELECTROLESS DEPOSITION OF COPPER. In Schlesinger, M. and Paunovic, M. (Ed.) Modern Electroplating. 5th ed. Hoboken: John Wiley & Sons, Inc. 2010, pp. 433-446. [3] Wang et al. Metallization of multi-walled carbon nanotubes with copper by an electroless deposition process. Electrochemistry Communications 6 (2004) pp. 1042–1044. ![]() |
Anjan Mukherjee: An Imprinting Technique to Fabricate Embedded Single GaAs Nanowire(NW)/Graphene Hybrid Devices
Anjan Mukherjee(1), Dong-chul kim(1,2), Hoyeol Yun(3), Miri Seo(4), Jung Tae Nam(5), Keun Soo Kim(5), Sang Wook Lee(4), A. Mazid Munshi(2), Dasa L. Dheeraj(2), Bjørn-Ove Fimland(1,2), Helge Weman(1,2) (1) Department of Electronic Systems, Norwegian University of Science and Technology, NO-7491, Trondheim, Norway (2) Crayonano As, Otto Nielsens vei 12, NO-7052, Trondheim, Norway (3) School of Physics, Konkuk University, 143 071, Seoul, Republic of Korea (4) Department of Physics, Ewha Womans University,120 750, Seoul, Republic of Korea (5) Department of physics and Graphene Research Institute, Sejong University, 143 747, Seoul, Republic of Korea In this report, we present the fabrication process of single GaAs NW/graphene hybrid devices with a planar junction configuration. A position-controlled micro transfer and imprinting technique that enables us to choose a single NW (or graphene) selectively on a target graphene (or a single NW) for high quality junction has been developed. Both GaAs NW/graphene bottom-and top-contact devices will be presented. For the fabrication of the first approch, we utilized the weak nature of adhesion between a polymer resist and a hydrophobic surface. For graphene/single NW top- contact devices, a key issue is how to make single NW embedded in a flat-surfaced structure, which is critical for the successful transfer of graphene on top of the NWs. Using a curable photo- resist layer, single NW could be transferred and imprinted for the embedded NW structure. [1] Xiaoqiang Li et al., Nano Energy, 16(2015) 310-319 [2] Sander A. Mann et al., Nature Nanotechnology, 11(2016) 1071-1075 [3] FuX. W. et al., Appl. Phys. Lett, 100(2012) 223114 ![]() |
Mohammad Hassan Ramezan zadeh: Iron oxide reinforced carbon nanotubes as promising nanofillers for biosensing applications of polymer films
Mohammad Hassan Ramezan zadeh, Majid Seifi Department of Physics, Faculty of Science, University of Guilan, Rasht 41335, Iran ![]() We have studied the influence of single walled carbon nanotubes coated with iron oxide nanoparticles (SWCNT-iron oxide nanocomposites) on the electrochemical properties of 2- dimensional polymer matrices and applied them as the frontier materials in electrochemical biosensors. In the present study, first, we synthesized SWCNT-iron oxide nanocomposites by following a same methodology reported previously [3], and then used them as nanofillers in gelatin films to make them applicable materials for electrochemical sensing in different branches, such as food industry, high-tech packaging, new medicine, biomedical devices, agricultural industry etc. This novel work could increase the different real-life applications of electrochemical biosensors for modern mankind as well as the over-increasing elderly population health care issues. 1. Irina V. Zaporotskova, et al. "Carbon nanotubes: Sensor properties. A review." Modern Electronic Materials 2.4 (2016): 95-105. 2. Xiaoxing Zhang, et al. "Mechanism and Application of Carbon Nanotube Sensors in SF6 Decomposed Production Detection: a Review." Nanoscale research letters 12.1 (2017): 177. 3. Mohammad Hassan Ramezan zadeh, et al. "Preparation and study of the electrical, magnetic and thermal properties of Fe 3 O 4 coated carbon nanotubes." Chinese Journal of Physics (2017). ![]() |
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