Abstracts‎ > ‎


Poster abstracts submitted before deadline for Carbonhagen 2015 can be found below... 

In addition  we accept post-deadline posters - write name, affilation, title and abstract to abstract@carbonhagen.com and request for a spot. 

Jaime E. Santos: Renormalisation of nanoparticles’ polarisability in the vicinity of a graphene-covered interface

posted 28 Jul 2015, 05:12 by info admin

Jaime E. Santos 1, M. I. Vasilevskiy 2, N. M. R. Peres 2, G. Smirnov 2, Yu. V. Bludov 2
1- DTU Nanotech, Building 345B, Ørsteds Pl., 2800 Kongens Lyngby, Denmark 2- Centro de Fisica e Departamento de Fisica, Universidade do Minho, 4710-057 Braga, Portugal

We study the electromagnetic properties of a metamaterial consisting of polarisable (nano)-particles and a single graphene sheet placed at the interface between two dielectrics. We show that the particle's polarisability is renormalised because of the electromagnetic coupling to surface plasmons supported by graphene, which results in a dispersive behavior, different for the polarisability components corresponding to the induced dipole moment, parallel and perpendicular to the graphene sheet. In particular, this effect is predicted to take place for a metallic particle whose bare polarisability in the terahertz (THz) region is practically equal to the cube of its radius (times 4πε
0). This opens the possibility to excite surface plasmons in graphene and enhance its absorption in the THz range by simply using a monolayer of metallic particles randomly deposited on top of it, as we show by explicit calculations [1].

[1] Jaime E. Santos, M. I. Vasilevskiy, N. M. R. Peres, G. Smirnov, Yu. V. Bludov, Phys. Rev. B 90, 235420 (2014)

Jaime E. Santos received his degree in Physics from the University of Porto, Portugal, in 1993 and his DPhil in Theoretical Physics from the University of Oxford, in the UK, in 1997. Since then, he has held positions at the TUM in Munich, at the Hahn Meitner Institute in Berlin, and at the Universities of Porto and Minho in Portugal. Currently, he is a Guest Scientist at the CNG, DTU Nanotech, holding a position as Temporary Associate Professor (Lektor). His main interest is the Physics of Graphene and related two-dimensional materials, in particular the transport properties and the optical properties of such systems, but he has also interests in Non-Equilibrium Thermodynamics of Quantum Systems and the Physics of Solar Cells.

Joachim D. Thomsen: In-situ TEM patterning and electrical characterization of graphene

posted 28 Jul 2015, 05:09 by info admin

Joachim D. Thomsen, Carsten Gade, Peter Bøggild, Tim J. Booth
Department of Micro and Nanotechnology, Technical University of Denmark

Transmission electron microscopy is a characterization tool able to obtain atomic scale resolution, and can also be used to nanopattern graphene. We have designed a micro-fabricated platform with on-chip heating and electrical contacts for in-situ environmental TEM characterization and modification of graphene and other 2D materials. We will present our initial results on graphene constrictions and interflake conductance of twisted bilayers.

Joachim Dahl Thomsen is a PhD student in the Nanocarbon Group at the Department of Micro and Nanotechnology, Technical University of Denmark (DTU), under supervision of Associate Professor Tim J. Booth and Professor Peter Bøggild. He works with in-situ transmission electron microscopy experiments (TEM) involving patterning and electrical characterization of graphene and other 2D materials, as well as optimization and micro-fabrication of platforms compatible with TEM holders for such experiments. Joachim received his M.Sc. degree in Physics and Nanotechnology from DTU in 2014 where he worked with cleanroom micro-fabrication of flexible arrays of photodetectors in his final project.

Ling Zhang: Electrocatalysis of chemically synthesized noble metal nanoparticles on carbon electrodes

posted 28 Jul 2015, 05:06 by info admin

Ling Zhang, Jens Ulstrup, Jingdong Zhang*
Department of Chemistry, NanoChemistry group, Technical University of Denmark (DTU), Denmark,

Noble metal nanoparticles (NPs), such as platinum (Pt) and palladium (Pd) NPs are promising catalysts for dioxygen reduction and oxidation of molecules such as formic acid and ethanol in fuel cells. Carbon nanomaterials are ideal supporting materials for electrochemical catalysts due to their good conductivity, chemical inertness and low cost [1]. Improvement of catalytic efficiency and stability of the NPs is, however, essential for their wider applications in electrochemical energy conversion/storage. The activities of noble metal catalysts depend not only on their size, composition, and shapes [2] but also on their interfacial interaction with the supporting electrodes. In this work we aim at chemical production of size and shape controlled, specifically 22 nm cubic Pd NPs, and further understanding of the Pd NPs as electrocatalysts at the nanometer scale using both scanning tunneling microscopy (STM) and atomic force microscopy (AFM) which have proved to be highly efficient techniques to map the in situ structures of self-assembled molecular monolayers at molecular or sub-molecular resolution [3]. Electrocatalysis of the Pd NPs immobilized on atomically flat, highly oriented pyrolytic graphite (HOPG) will be investigated by electrochemical SPM. This study offers promise for development of new high-efficiency catalyst types with low-cost for fuel cell technology.

  1. Y. S. Jeong, J.-B. Park, H.-G. Jung, J. Kim, X. Luo, J. Lu, L. Curtiss, K. Amine, Y.-K. Sun, B. Scrosati and Y. J. Lee, Nano Lett., 2015, 15, 4261-4268.
  2. L. Zhang, W. Niu and G. Xu, Nano Today, 2012, 7, 586-605.
  3.  J. Zhang, A. C. Welinder, Q. Chi and J. Ulstrup, Phys. Chem. Chem. Phys., 2011, 13, 5526-5545.                

Ling Zhang is a postdoc in the NanoChemistry group, Department of Chemistry, Technical University of Denmark (DTU). The current project is supported by The H.C. Ørsted COFUND Program. Her research interests focus on shape controlled synthesis of colloidal noble metal nanocrystals and their electrochemical catalytic properties, electron transfer of molecules and biomolecules, and electrochemical catalysis of 2D materials. She has a strong expertise in scanning probe microscopy, electrochemical catalysis, synthesis of shape controlled colloidal noble metal nanocrystals, and structural analysis of nanoparticles. She obtained her Ph. D. degree at Changchun Institute of Applied Chemistry, Chinese Academy of Sciences (CAS) in 2014 and a bachelor degree at Department of Chemistry of Jilin University in 2008. She worked at Department of Physics, Hong Kong Polytechnic University as a Research Associate in the electrocatalysis of 2D materials in 2014. She won the scholarship of the joint CAS-CNRS doctoral promotion program and worked on enzyme projects at Université Paris Diderot in 2012.  She has published more than 20 papers, including papers in ACS Nano, Nano Today, and Analytical Chemistry, and has attended five international conferences in nanomaterials and electrochemistry.

Sharali Malik: Characterization of Few-layer Graphene (FLG) starting with Pristine Graphite via Wet Chemical Functionalization.

posted 28 Jul 2015, 05:02 by info admin

Sharali Malik, Colin Liebscher, George Kostakis, Di Wang, Stefanie Portratz, Silviu Balaban, Carmen Balaban

Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany. 
Aix-Marseille Université, Institut des Sciences Moléculaires de Marseille, 13397 Marseille cedex 20, France.

Few-layer graphene (less than 10 stacked layers) possess outstanding electronic and mechanical properties. However, graphene has a gapless band-structure and is not solution processable. Chemical functionalization has been used to address these problems by covalent modification of graphene’s π-electron system in association with wet chemical exfoliation. Here we show new synthetic methods which also achieves this goal. Starting with pristine graphite we have obtained few-layer functionalized graphene. These materials were characterized by Raman spectroscopy, x-ray diffraction and TEM. In this poster, we show that, we can apply analagous methods to those we reported to functionalize carbon nanotubes for the preparation of large quantities of graphene sheets. The research picture shows a detail HRTEM view of a graphene and FLG flake.

Sharali Malik is a Chartered Chemist with many years practical experience as a scientist in academia as well as in industry. This includes three years’ experience of battery R&D with Varta Ltd,  three years’ experience of computer modeling of long-range transmission of air pollutants in Europe (EMEP/MSC-W), three years’ experience of advising on, implementing and enforcing Health and Safety at Work  as a UK Government Inspector, and fourteen years’ experience of Physical Chemistry research in his current position at Karlsruhe Institute of Technology (KIT) in the Institute of Nanotechnology (INT) working on the Synthesis and Characterization of Nano-Carbon Materials.

Filip Anselm Rasmussen: Computational 2D Materials Database: Electronic Structure of Transition Metal Dichalcogenides and Oxides

posted 28 Jul 2015, 04:58 by info admin

F. Anselm Rasmussen, K. Sommer Thygesen
Center for Nanostructured Graphene, Dept. of Physics, Technical University of Denmark

We present a comprehensive first-principles study of the electronic structure of 51 semiconducting monolayer transition metal dichalcogenides and -oxides in the 2H and 1T hexagonal phases. The quasiparticle (QP) band structures with spin-orbit coupling are calculated in the G0W0 approximation and comparison is made with different density functional theory (DFT) descriptions. Pitfalls related to the convergence of GW calculations for 2D materials are discussed together with possible solutions. The monolayer band edge positions relative to vacuum are used to estimate the band alignment at various heterostructure interfaces. The sensitivity of the band structures to the inplane lattice constant is analysed and rationalized in terms of the electronic structure. Finally, the q-dependent dielectric functions and effective electron/hole masses are obtained from the QP band structure and used as input to a 2D hydrogenic model to estimate exciton binding energies.

Filip Anselm Rasmussen is working as a PhD student at the Center for Nanostructured Graphene (CNG) and Center for Atomic Scale Materials Design (CAMd) at the Department of Physics at the Technical University of Denmark under the supervision of Professor Kristian Thygesen. His work aims at calculating the electronic excitations of novel 2D materials using computational first principles methods.

Arnab Halder: Mussel-inspired bio functionalization of graphene for electrochemical sensor applications

posted 28 Jul 2015, 04:01 by info admin

Arnab Halder and Qijin Chi*
NanoChemistry Group, Department of Chemistry, Technical University of Denmark, Kongens Lyngby 2800, Denmark. *E-mail: cq@kemi.dtu.dk

Graphene has emerged as a wonder material in many fields ranging from physics and chemistry to biology in the past decade. [1] Wet-chemical synthesis methods offer low-cost production and facile functionalization of single-layered and solution suspended biocompatible graphene. [2] We here used a biologically active molecule “Dopamine” (DA) for the biofunctionalization. The unique properties of dopamine (DA) allow to be used simultaneously as a reducing agent for GO reduction and as a capping ligand to stabilize and decorate the resulting reduced GO (RGO) surface for further functionalization. Moreover, as the dopamine moiety contains a redox couple group, the hybrid material can be highly applicable to electrochemical sensing. The catechol group of dopamine was selectively protected to prevent from self-polymerization and undesirable side chain reactions. [3] After the coupling reaction with graphene oxide, deprotection reaction was carried out to recover free catechol groups in the RGO-DA nanocomposite. The HQ/Q- redox couple in DA moiety can be highly applicable to electrochemical sensing. Here we used this functionalized material for the electrochemical sensing of melamine with ultra-high sensitivity.
  1. D. R. Dreyer, S. Park, C. W. Bielawski and R. S. Ruoff, Chemical Society Reviews 2010, 39, 228-240.
  2. N. Zhu, S. Han, S. Gan, J. Ulstrup and Q. Chi, Advanced Functional Materials 2013, 23, 5297-5306.
  3. A. Halder, M. Zhang, G. Olsen and Q. Chi, Manuscript under preparation, 2015
Arnab Halder is currently a PhD student of Nanochemistry group at the Department of Chemistry, Technical University of Denmark. His research focuses on the biocompatible engineering functionalization of Graphene nanomaterials and their application in chemosensors and biosensors. 

Jonas Buron: Graphene Mobility Mapping by non-contact THz spectroscopy

posted 28 Jul 2015, 03:53 by info admin

Jonas D. Buron1, Filippo Pizzocchero1, Peter U. Jepsen2, Dirch H. Petersen1, José M. Caridad1, Bjarke S. Jessen1, Timothy J. Booth1,3, and Peter Bøggild1,3

1DTU Nanotech - Department of Micro- and Nanotechnology, Technical University of Denmark, Building 345 Ørsteds Plads, 2800 Kgs. Lyngby, Denmark

2DTU Fotonik - Department of Photonics Engineering, Technical University of Denmark, Building 343 Ørsteds Plads, 2800 Kgs. Lyngby, Denmark

3DTU Center for Nanostructured Graphene (CNG), DTU Nanotech - Department of Micro- and Nanotechnology, Technical University of Denmark, Building 345 Ørsteds Plads, 2800 Kgs. Lyngby, Denmark

Carrier mobility and chemical doping level are essential figures of merit for graphene, and large-scale characterization of these properties and their uniformity is a prerequisite for commercialization of graphene for electronics and electrodes. However, existing mapping techniques cannot directly assess these vital parameters in a non-destructive way. By deconvoluting carrier mobility and density from non-contact terahertz spectroscopic measurements of conductance in graphene samples with terahertz-transparent backgates, we are able to present maps of the spatial variation of both quantities over large areas. The demonstrated non-contact approach provides a drastically more efficient alternative to measurements in contacted devices, with potential for aggressive scaling towards wafers/minute. The observed linear relation between conductance and carrier density in chemical vapour deposition graphene indicates dominance by charged scatterers. Unexpectedly, significant variations in mobility rather than doping are the cause of large conductance inhomogeneities, highlighting the importance of statistical approaches when assessing large-area graphene transport properties. 

1.  J. D. Buron et al., Nano Lett., 2012, 12, pp. 5074-5081

Jonas Buron is currently a Post Doctoral fellow at the Technical University of Denmark.  He is primarily interested in the ultrafast electronic and optical properties of atomically thin materials such as graphene. He received his M.Sc. degree in Physics from the Technical University of Denmark (2010) and a Ph.D. in Physics (2013) from the Technical University of Denmark where he studied the terahertz transport dynamics of graphene charge carriers. During his Ph.D, he spent 4 months in the Teraherz Optical Science laboratory at the iCeMS (Institute for Integrated Cell-Material Sciences) studying the terahertz nearfirled response of graphene flakes.

Susanne Helene Jensen: Phosphate modified graphene oxide for controlling material surface and mechanical properties

posted 28 Jul 2015, 03:47 by info admin

Susanne Helene Jensen, Gunnar Olsen and Qijin Chi*
The NanoChemistry Group, Department of Chemistry, Technical University of Denmark, Kongens Lyngby 2800, Denmark. *E-mail: cq@kemi.dtu.dk

As a wonder material, graphene has offered a new platform for various applications in materials science and engineering. Chemical modification of graphene is a key step to introduce new and desirable functionality which combines with the intrinsic merits of graphene in optical and electronic properties. While pristine graphene is largely chemically inert, chemically exfoliated graphene oxide (GO), as a building-up starting material, possess the advantages including low-cost production and facile post-functionalization with wet-chemical methods. Both covalent and non-covalent methods are applicable to modifications of GO nanosheets [1]. To date, many studies have shown that GO and its reduced form, reduced graphene oxide (rGO), can be chemically modified through different types of chemical bonding but less to none using phosphorous bonding that could offer unique advantages such as tunable mechanical property [2]. In this work, we have systematically performed the studies on the synthesis and structural charaterization of phosphate attached GO (P-GO) or/and rGO nanosheets (P-rGO) [3], with the aim to generate mechanically strong as well as super-hydrophilic nanocomposites. Some key results will form a poster presented in this conference.      

  1. J. B. Goods, S. A. Sydlik, J. J. Walish and T. M. Swager, Adv. Mater. 2014, 26, 718-723.
  2. V. Georgakilas et al., Chem. Rev. 2012, 112, 6156−6214.
  3. S. H. Jensen, Master Thesis, Technical University of Denmark, 2015
Susanne H. Jensen is currently a master student under supervision of associate professor Qijin Chi, affiliated with the Nanochemistry group at the Department of Chemistry, Technical University of Denmark, and will fulfill her master degree in August 2015. She has studied applied chemistry and chemical engineering through the past 6 years. Susanne is interested in the research that can produce new materials for potential applications in chemical and mechanical engineering, with particularly keen to polymer-graphene nanocomposites. The poster presented in Carbonhagen 6 is the key part of the results obtained in her master thesis project. 

Line Kyhl: Hydrogen atoms adsorption configurations on graphene/Ir(111) – a study of the vibrational spectrum including phonons

posted 28 Jul 2015, 03:42 by info admin

L. Kyhla, T. Angotb, L. Hornekaera,c, R. Bissonb
a) Interdisciplinary Nanoscience Center, Aarhus University
b) PIIM/CNRS Aix-Marseille Université, France
c) Institute of Physics and Astronomy, Aarhus University, Denmark

The electronic and structural properties of hydrogenated graphene on Ir(111) have previously been studied using scanning tunneling microscopy (STM) and angle resolved photoemission spectroscopy (ARPES) [1]. These techniques show nanostructured hydrogenation, templated by the moiré structure and opening of a gap around the Fermi level of at least 450 meV [1]. Two different hydrogen adsorption configurations on graphene on Ir(111) are still under debate [2, 3]: i) Hydrogen adsorbs on the top (vacuum) side of the graphene sheet, stabilized by the formation of carbon-iridium bonds on the bottom (iridium) side of the graphene; a graphane-like conformation. ii) Chemisorption of hydrogen is stabilized by the hydrogen atom adsorption on both sides of the graphene sheet; real graphane.

In this work hydrogen atom adsorption on high-quality graphene on Ir(111) was investigated using high-resolution electron energy loss spectroscopy (HREELS). No evidence was found for hydrogen bound on both sides of a high quality graphene sheet and phonon features strongly suggest increased interactions between carbon and iridium atoms upon hydrogen atom exposure. The presented results lead to the conclusion that hydrogen atoms bind only on the top side of high-quality graphene on Ir(111).

  1. R. Balog, B. Jorgensen, L. Nilsson, M. Andersen, E. Rienks, M. Bianchi, M. Fanetti, E. Laegsgaard, A. Baraldi, S. Lizzit, Z. Sljivancanin, F. Besenbacher, B. Hammer, T. G. Pedersen, P. Hofmann and L. Hornekaer, Nature Materials, 2010, 9, 315-319
  2. R. Balog, M. Andersen, B. Jorgensen, Z. Sljivancanin, B. Hammer, A. Baraldi, R. Larciprete, P. Hofmann, L. Hornekaer and S. Lizzit, Acs Nano, 2013, 7, 3823-3832
  3. K. Hyunil, T. Balgar and E. Hasselbrink, Chemical Physics Letters, 2012, 546, 12-17
Line Kyhl is currently a PhD student in Nanoscience at iNANO, Aarhus University.
  She primarily studies functionalization of graphene on metal surfaces using scanning tunneling microscopy (STM), Raman spectroscopy and x-ray photoemission spectroscopy (XPS). Additionally, she is highly involved in the National Initiative for Advanced Graphene Coatings and Composites (NIAGRA) project developing graphene-based anti-corrosion coatings for metals. Line has an ongoing collaboration at Aix-Marseille university studying the vibrational properties of graphene samples using high-resolution electron energy loss spectroscopy (HREELS). Additionally she has initiated a collaboration at Lawrence Berkeley National Laboratory, California, studying graphene coatings using near-ambient pressure XPS (NAPXPS). She will obtain her PhD degree in July 2017.

David Mackenzie: High-speed debris-free laser fabrication of wafer-scale graphene devices

posted 27 Jul 2015, 05:08 by info admin

David M. A. Mackenzie*, Jonas D. Buron, Patrick R Whelan, Bjarke S. Jessen, Adnan Silajdzic, Amaia Pesquera, Alba Centeno, Amaia Zurutuza, Peter Bøggild, Dirch H. Petersen
Department of Micro & Nanotechnology, Technical University of Denmark, Building 345E, 2800 Kgs. Lyngby, Denmark

As graphene is up-scaled to wafer-sized production, it is important to have a robust, fast and accurate method for routine characterization of the electrical properties on large scale. Here we consider a fabrication procedure involving wafer-scale laser fabrication of graphene devices to serve this purpose. The inherent advantages of this method include the high speed of device fabrication and the prevention of degradation of the electrical properties associated with traditional lithographic methods:  i.e. avoiding contact to polymers/liquids, known to adversely affect the electrical properties [1].

Commercially purchased CVD graphene (covering a 4-inch Si wafer on SiO2) has metal electrodes (Ti/Au) deposited using electron-beam evaporation through a stencil shadow mask. The graphene is then patterned via ablation (see Figure 1) with a pulsed laser to define large devices (Hall bars or van der Pauw geometries), enabling the large-scale electrical properties to be tested.

Optical microscopy and Raman Spectroscopy were used to assess ablation of the graphene, as well as stylus profilometery indicating no damage of the SiO2 substrate. CVD graphene devices were electrically characterized and showed comparable field-effect mobility, doping level, on-off ratio, and conductance minimum before and after laser ablation fabrication.

[1] A. M. Goossens, V. E. Calado, A. Barreiro, K. Watanabe, T. Taniguchi, L. M. K. Vandersypen, Appl. Phys. Lett. 100, 073110 (2012)

David Mackenzie is a postdoctoral researcher in the Nanocarbon group based at the Department of Micro & Nanotechnology, Technical University of Denmark. Research interests include fabricating graphene devices, electrical and gas sensing measurements.

1-10 of 30