DOCSLIB.ORG

Creating Value from Non-Carbon 2D Materials

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Creating Value from Non-Carbon 2D Materials Creating Value from Non-carbon 2D Materials - Beyond Graphene A state of the art review Contact Graphene and Other 2D Materials SIG www.ktn-uk.co.uk/interests/graphene-and-other-2d-materials Table of contents Executive Summary 5 Glossary of Non-Carbon 2D Materials 7 1. Introduction 8 2. Family of Non-Carbon 2D Materials 11 3. Synthesis and Production of Non-Carbon 2D Materials 15 4. The Innovation Landscape for Non-Carbon 2D Materials 19 5. Strategic Insights for the UK 35 6. Conclusions 42 7. Priorities and Recommendations 43 Acknowledgements 44 References 45 Appendix 1: Examples of R&D and Innovations 46 Appendix 2: Patent Analysis 48 3 4 Martin Good / Shutterstock.com Executive Summary The ability to isolate or grow two-dimensional with specially designed electrical, magnetic, (2D) materials has been a source of scientific piezoelectric and optical functionalities. fascination ever since it was shown to be possible, Research in non-carbon 2D materials has with the isolation of graphene from graphite, benefited from the earlier investments in in 2004 at the University of Manchester. The developing graphene. They can be manufactured increasing range of 2D materials extends far in a similar way and can be combined with beyond graphene and its carbon analogues. It is graphene to address its lack of band gap. Band believed that over five hundred 2D materials have gap is a property that makes silicon and other been developed globally so far. These materials semiconductors so useful for digital electronics. exhibit an exciting range of novel properties, 2D semiconducting materials are likely to become opening the door to a multitude of new potential an attractive choice for constructing digital applications. circuits on flexible and transparent substrates Graphene remains the most famous of for applications such as paper-like transparent these 2D materials, with developments well displays, wearable electronics and photonic advanced. However, research in non-carbon 2D devices. materials is accelerating at a rapid pace with Many application sectors recognise the benefits significant contributions from UK research they can derive from these new materials groups and materials producing SMEs. Clear and have expressed the need to have greater progress has been made with the commercial understanding of the industrial challenges they availability of hexagonal Boron Nitride, h-BN, will face. This led to the KTN undertaking a short and the growing industry interest in transition- project to bring together leading companies and metal dichalcogenides (TMDCs), in particular academics working on 2D materials and devices semiconductor TMDCs such as molybdenum from across the UK. The KTN also met with disulphide (MoS ), which have direct band gap 2 potential industry users and the wider supply and are attractive for optics and optoelectronic chain to explore the challenges faced in bringing devices. There is also a particular excitement these 2D materials to market. The output from about the ability to custom stack thin layers of the project includes this state of the art report, non-carbon 2D materials and, in combination which reviews the current innovation landscape with graphene, create hetero-structured devices. and captures the views of senior academics and These devices have a variety of different electronic industrialists, regarding where the UK should and optical properties, which can be finely tuned be headed to create commercial value from by careful design of the stack. Ongoing research developments in non-carbon 2D materials. is showing great promise for new materials 5 This KTN study has identified a body of work Following considerable discussions with being undertaken globally to develop non-carbon industry experts and academics, the following 2D materials, mainly led by university research recommendations are made to both groups. Companies such as Samsung and IBM government and industry to drive forward the are active in this area, as are UK SMEs such as commercialisation of non-carbon 2D materials in Thomas Swan and 2D-Tech, part of Versarian Plc. the UK. The discussions KTN has had with UK companies 1. Create an Industry Challenge around h-BN suggest that existing businesses developing and TMDCs to accelerate the development of graphene are the ones most likely to look at supply chain and end user partnerships. exploiting other 2D materials. 2. Provide 5-10 years long term funding for The following were noted as the priorities for the centres of excellence to carry out more work UK in our bid to create commercial value from needed in scale-up of non-carbon 2D material current academic research and industry activities: production, device fabrication and end-user • More industry collaboration needed to scale applications. up the manufacturing and use of 2D materials; 3. Invest in scaled-up demonstrators to show and • UK industry to work closely with academic exploit the game changing properties of non- researchers to develop technology roadmaps carbon 2D materials, solely or in combination for mass production and application of 2D with graphene. materials; 4. Consider the overall UK landscape and • Funding needed to improve manufacturing impact of the EU Graphene Flagship project techniques for 2D materials, including device on leveraged funding for development and fabrication and product manufacture. commercialisation activities. 6 Glossary of Non-Carbon 2D Materials CuO Copper oxide SnS2 Tin disulfide h-BN Hexagonal boron nitride SnSe2 Tin diselenide HfS2 Hafnium disulfide TaS 2 Tantalum disulfide LaNb2O7 Lanthanum niobate TiO2 Titanium dioxide MnO2 Manganese dioxide TiS2 Titanium disulfide MoO3 Molybdenum trioxide TiSe2 Titanium diselenide MoS2 Molybdenum disulfide TMDC Transition-metal dichalcogenides MoSe2 Molybdenum diselenide VS2 Vanadium disulfide MoTe2 molybdenum ditelluride VSe2 Vanadium diselenide NbS2 Niobium disulfide WO3 Tungsten trioxide NbSe2 Niobium diselenide WS2 Tungsten disulfide Ni(OH)2 Nickel hydroxide WSe2 Tungsten diselenide ReS2 Rhenium disulfide WTe 2 Tungsten ditelluride ReSe2 Rhenium diselenide ZrS2 Zirconium disulfide RuO2 Ruthenium dioxide 7 1. Introduction Two-dimensional (2D) materials are a new and ability to build custom-made structures (hetero- expanding family of materials with exceptional structures) by stacking combinations of 2D properties. Graphene is currently the most materials on top of each other and constructing famous of these 2D materials, which although one libraries of crystals to provide specific electrical, million times thinner than paper is the strongest thermal, physical or mechanical properties and material known to science. It is made up of carbon functionalities. atoms arranged in a hexagonal lattice and has A number of these non-carbon 2D materials many superlative properties to its credit. The address graphene’s lack of band gap, which is unique combination of superior electrical, optical what makes silicon and other semiconductors so and mechanical properties makes graphene an useful for digital electronics. 2D semiconducting incredible material for diverse applications across materials are likely to become an attractive many sectors. The UK has been a global leader choice for constructing digital circuits on flexible in research on graphene since its isolation from and transparent substrates for applications such graphite crystal at the University of Manchester in as paper-like transparent displays, wearable 2004. electronics and photonic devices. In addition, the The ability to isolate or grow 2D materials has mechanical properties of MoS2 also appear to been a source of scientific fascination ever since be very attractive. It is thought that there may it was shown to be possible. The isolation of be around five hundred 2D materials already graphene has led to the discovery of a whole developed, globally, including graphene. family of 2D materials, including large numbers Research in non-carbon 2D materials has of atomic layers derived from non-carbon 2D benefited from the earlier investments in materials such as hexagonal boron nitride (h-BN) developing graphene with activities in areas and molybdenum disulphide (MoS ). These can be 2 of material structure-property correlations, combined with graphene to create exciting new synthesis and nanofabrication, device integration devices and products. This field is accelerating at and device characterisation studies. a rapid pace and significant contributions have been made by UK researchers. This includes the 8 Many application sectors recognise the benefits Definition of 2D Materials they can derive from these new materials An ISO terminology standard has been developed and have expressed the need to have greater to provide a common definition of 2D materials. understanding of the industrial challenges they It defines 2D materials as “one or several layers will face. This led to the KTN undertaking a short with the atoms in each layer strongly bonded to project to bring together leading companies and neighbouring atoms in the same layer, which has academics working on 2D materials and devices one dimension, its thickness, in the nanoscale or from across the UK. The KTN also met with smaller, and the other two dimensions generally potential industry users and the wider supply at “larger scales”. See ISO/TS 80004-13:2017: chain to explore the challenges faced in bringing ‘Graphene and related two-dimensional (2D) these 2D materials to market. The output from materials’. the project includes this state of the art report,
Load more

Recommended publications
  • Effects of Metal Contacts and Doping for High
    TW-P061 Effects of metal contacts and doping for high-performance field-effect transistor based on tungsten diselenide (WSe2) Seo-Hyeon Jo and Jin-Hong Park School of Electronics and Electrical Engineering, Sungkyunkwan University, Suwon 440-746, Korea Transition metal dichalcogenides (TMDs) with two-dimensional layered structure, such as molybdenum disulfide (MoS2) and tungsten diselenide (WSe2), are considered attractive materials for future semiconductor devices due to its relatively superior electrical, optical, and mechanical properties. Their excellent scalability down to a monolayer based on the van der Waals layered structure without surface dangling bonds makes semiconductor devices based on TMD free from short channel effect. In comparison to the widely studied transistor based on MoS2, researchs focusing on WSe2 transistor are still limited. WSe2 is more resistant to oxidation in humid ambient condition and relatively air-stable than sulphides such as MoS2. These properties of WSe2 provide potential to fabricate high-performance filed-effect transistor if outstanding electronic characteristics can be achieved by suitable metal contacts and doping phenomenon. Here, we demonstrate the effect of two different metal contacts (titanium and platinum) in field-effect transistor based on WSe2, which regulate electronic characteristics of device by controlling the effective barreier height of the metal-semiconductor junction. Electronic properties of WSe2 transistor were systematically investigated through monitoring of threshold voltage shift, carrier concentration difference, on-current ratio, and field-effect mobility ratio with two different metal contacts. Additionally, performance of transistor based on WSe2 is further enhanced through reliable and controllable n-type doping method of WSe2 by triphenylphosphine (PPh3), which activates the doping phenomenon by thermal annealing process and adjust the doping level by controlling the doping concentration of PPh3.
    [Show full text]
  • Tungsten Disulfide: a Novel Hydrogen Evolution Catalyst for Water Decomposition Andrzej Sobczynski, Attila Yildiz, Allen J
    Subscriber access provided by University of Texas Libraries Tungsten disulfide: a novel hydrogen evolution catalyst for water decomposition Andrzej Sobczynski, Attila Yildiz, Allen J. Bard, Alan Campion, Marye Anne Fox, Thomas Mallouk, Stephen E. Webber, and John M. White J. Phys. Chem., 1988, 92 (8), 2311-2315 • DOI: 10.1021/j100319a042 Downloaded from http://pubs.acs.org on February 2, 2009 More About This Article The permalink http://dx.doi.org/10.1021/j100319a042 provides access to: • Links to articles and content related to this article • Copyright permission to reproduce figures and/or text from this article The Journal of Physical Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 J. Phys. Chem. 1988, 92, 2311-2315 2311 Tungsten Dlsulflde: A Novel Hydrogen Evolution Catalyst for Water Decomposition Andrzej Sobczynski; Attila Yildiz,* Allen J. Bard, Alan Campion, Marye Anne Fox, Thomas Mallouk, Stephen E. Webber, and John M. White* Department of Chemistry, University of Texas, Austin, Texas 78712 (Received: July 27, 1987: In Final Form: November 24, 1987) Silica-supported tungsten disulfide was prepared by the reaction of W03/Si02with H2S at 300 OC. The WS2 hexagonal structure was confirmed by X-ray diffraction analysis. AES and XPS studies show the existence of residual tungsten oxides in addition to WS2. Hydrogen evolution properties of WS2/Si02were determined by catalytic and photocatalytic (in the presence of fluorescein or CdS as sensitizers) tests and by electrochemical measurements. These were compared with silica-supported platinum. Although a graphite electrode immersed in a Pt/Si02 slurry evolved hydrogen at a more positive applied potential than in a WS2/Si02slurry, silica-supported tungsten disulfide was more active and stable than Pt/Si02 for catalytic hydrogen production both in the dark and under visible light illumination (with cadmium sulfide as a sensitizer).
    [Show full text]
  • Very High Refractive Index Transition Metal Dichalcogenide Photonic Conformal Coatings by Conversion of ALD Metal Oxides
    Lawrence Berkeley National Laboratory Recent Work Title Very High Refractive Index Transition Metal Dichalcogenide Photonic Conformal Coatings by Conversion of ALD Metal Oxides. Permalink https://escholarship.org/uc/item/5131q4m6 Journal Scientific reports, 9(1) ISSN 2045-2322 Authors Chen, Christopher T Pedrini, Jacopo Gaulding, E Ashley et al. Publication Date 2019-02-26 DOI 10.1038/s41598-019-39115-3 Peer reviewed eScholarship.org Powered by the California Digital Library University of California www.nature.com/scientificreports OPEN Very High Refractive Index Transition Metal Dichalcogenide Photonic Conformal Coatings by Received: 17 September 2018 Accepted: 17 January 2019 Conversion of ALD Metal Oxides Published: xx xx xxxx Christopher T. Chen 1, Jacopo Pedrini2, E. Ashley Gaulding3, Christoph Kastl1, Giuseppe Calafore1, Scott Dhuey1, Tevye R. Kuykendall1, Stefano Cabrini1, Francesca M. Toma 3, Shaul Aloni1 & Adam M. Schwartzberg1 Materials for nanophotonic devices ideally combine ease of deposition, very high refractive index, and facile pattern formation through lithographic templating and/or etching. In this work, we present a scalable method for producing high refractive index WS2 layers by chemical conversion of WO3 synthesized via atomic layer deposition (ALD). These conformal nanocrystalline thin flms demonstrate a surprisingly high index of refraction (n > 3.9), and structural fdelity compatible with lithographically defned features down to ~10 nm. Although this process yields highly polycrystalline flms, the optical constants are in agreement with those reported for single crystal bulk WS2. Subsequently, we demonstrate three photonic structures - frst, a two-dimensional hole array made possible by patterning and etching an ALD WO3 thin flm before conversion, second, an analogue of the 2D hole array frst patterned into fused silica before conformal coating and conversion, and third, a three- dimensional inverse opal photonic crystal made by conformal coating of a self-assembled polystyrene bead template.
    [Show full text]
  • Thesis Submitted for the Degree of Doctor of Philosophy
    University of Bath PHD Development of Single-Source CVD Precursors for Group IV, V and VI Metal Disulfides Thompson, Joseph Award date: 2017 Awarding institution: University of Bath Link to publication Alternative formats If you require this document in an alternative format, please contact: [email protected] General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Download date: 11. Oct. 2021 Development of Single-Source CVD Precursors for Group IV, V and VI Metal Disulfides Joseph Robert Thompson A thesis submitted for the degree of Doctor of Philosophy University of Bath Department of Chemistry October 2016 COPYRIGHT Attention is drawn to the fact that copyright of this thesis/portfolio rests with the author and copyright of any previously published materials included may rest with third parties. A copy of this thesis/portfolio has been supplied on condition that anyone who consults it understands that they must not copy it or use material from it except as permitted by law or with the consent of the author or other copyright owners, as applicable.
    [Show full text]
  • Transition Metal Dichalcogenide Metamaterials with Atomic Precision
    ARTICLE https://doi.org/10.1038/s41467-020-18428-2 OPEN Transition metal dichalcogenide metamaterials with atomic precision Battulga Munkhbat 1, Andrew B. Yankovich 1, Denis G. Baranov 1,2, Ruggero Verre1, Eva Olsson 1 & ✉ Timur O. Shegai 1 The ability to extract materials just a few atoms thick has led to the discoveries of graphene, monolayer transition metal dichalcogenides (TMDs), and other important two-dimensional 1234567890():,; materials. The next step in promoting the understanding and utility of flatland physics is to study the one-dimensional edges of these two-dimensional materials as well as to control the edge-plane ratio. Edges typically exhibit properties that are unique and distinctly different from those of planes and bulk. Thus, controlling the edges would allow the design of materials with combined edge-plane-bulk characteristics and tailored properties, that is, TMD meta- materials. However, the enabling technology to explore such metamaterials with high pre- cision has not yet been developed. Here we report a facile and controllable anisotropic wet etching method that allows scalable fabrication of TMD metamaterials with atomic precision. We show that TMDs can be etched along certain crystallographic axes, such that the obtained edges are nearly atomically sharp and exclusively zigzag-terminated. This results in hexagonal nanostructures of predefined order and complexity, including few-nanometer-thin nanoribbons and nanojunctions. Thus, this method enables future studies of a broad range of TMD metamaterials through atomically precise control of the structure. 1 Department of Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden. 2 Center for Photonics and 2D Materials, Moscow Institute of ✉ Physics and Technology, Dolgoprudny 141700, Russia.
    [Show full text]
  • Download This Article PDF Format
    Nanoscale View Article Online PAPER View Journal | View Issue Large-area tungsten disulfide for ultrafast photonics Cite this: Nanoscale, 2017, 9, 1871 Peiguang Yan,*a Hao Chen,a Jinde Yin,a Zihan Xu,b Jiarong Li,a Zike Jiang,a Wenfei Zhang,a Jinzhang Wang,a Irene Ling Li,a Zhipei Sunc and Shuangchen Ruan*a Two-dimensional (2D) layered transition metal dichalcogenides (TMDs) have attracted significant interest in various optoelectronic applications due to their excellent nonlinear optical properties. One of the most important applications of TMDs is to be employed as an extraordinary optical modulation material (e.g., the saturable absorber (SA)) in ultrafast photonics. The main challenge arises while embedding TMDs into fiber laser systems to generate ultrafast pulse trains and thus constraints their practical applications. Herein, few-layered WS2 with a large-area was directly transferred on the facet of the pigtail and acted as a SA for erbium-doped fiber laser (EDFL) systems. In our study, WS2 SA exhibited remarkable nonlinear optical properties (e.g., modulation depth of 15.1% and saturable intensity of 157.6 MW cm−2) and was Creative Commons Attribution 3.0 Unported Licence. used for ultrafast pulse generation. The soliton pulses with remarkable performances (e.g., ultrashort pulse duration of 1.49 ps, high stability of 71.8 dB, and large pulse average output power of 62.5 mW) Received 25th November 2016, could be obtained in a telecommunication band. To the best of our knowledge, the average output Accepted 29th December 2016 power of the mode-locked pulse trains is the highest by employing TMD materials in fiber laser systems.
    [Show full text]
  • The Preparation and Properties of Tase2 Single Crystal
    International Journal of Physics and Mathematical Sciences ISSN: 2277-2111 (Online) An Open Access, Online International Journal Available at http://www.cibtech.org/jpms.htm 2016 Vol. 6 (1) January-March, pp. 11-16/Patel and Lakhataria. Research Article SYNTHESIS AND STRUCTURAL ANALYSIS OF NBSE2 SINGLE CRYSTALS *Kaushik R Patel1 and Duhita Lakhataria2 1Biogas Research Center, Mahadevbhai Desai Gramseva Mahavidhyalaya, Gujarat Vidyapith, Sadra 382 320 2Government Polytechnique College, Amadavad *Author for Correspondence ABSTRACT The transition metal dichalcogenides NbS2 and NbSe2 are layer compounds consisting of sandwiches with strong covalent/ionic intra layer bonds and weak Van der Waals interlayer interactions. The NbSe2 single crystals were grown by chemical vapour transport technique (CVT) using iodine as transporting agent. The chemical compositions of the grown crystals were confirmed with the help of energy dispersive analysis by X-ray (EDAX). The structural properties were studied by X- ray diffraction analysis (XRD). The crystals were found to possess hexagonal crystal structure. The lattice parameters, unit cell volume, grain size and X-ray density were computed for this crystal. The results obtained are discussed in detail. Keywords: Crystal Growth, Semiconductor, EDAX, XRD, Lattice Parameters PACS Nos.: 61.50.Nw, 61.10.Nz, 81.40.Tv INTRODUCTION The transition metal dichalcogenides, NbS2 and NbSe2 are layered compounds consisting of sandwiches with strong covalent/ionic intra layer bonds and weak van der Waals interlayer interactions. The stacking sequence of S and Nb are AcA BcB (2H- NbS2 structure) or AbA BcB CaC (3R- MoS2 structure) for NbSe2 several more stacking sequences exist (Lieth et al., 1977; Boswell et al., 1976; Harper, 1977).
    [Show full text]
  • Exploring Optoelectronics Potential of Monolayer Tungsten Diselenide
    60 Technical focus: Optoelectronics Exploring optoelectronics potential of monolayer tungsten diselenide Three groups have recently reported on preliminary experiments with photovoltaic and light-emission effects from pn junctions created using split-gate electrostatic doping. Mike Cooke reports. esearchers are beginning to explore the semi- both convert light into current and current into light. conductor potential of monolayer materials The creation of n- and p-type conductivity in these Rbeyond graphene with hopes of developing devices was achieved electrostatically with a split gate robust devices that are flexible and transparent for beneath the WSe2 monolayer. deployment in wearable formats, interactive displays, Vienna University of Technology [Andreas Pospischil and efficient solar cells. et al, Nature Nanotechnology, vol 9 (2014), p257] An interesting class of materials that has recently come began its fabrication by forming a split gate of titanium/ to the fore is that of few-layer group-VIB transition-metal gold with a 460nm gap on a silicon/silicon dioxide dichalcogenides (TMDs) such as molybdenum disulfide wafer (Figure 1). Gate bonding pads were also formed (MoS2), molybdenum diselenide (MoSe2), tungsten with titanium/gold. The split gate was covered with disulfide (WS2), and tungsten diselenide (WSe2). silicon nitride, except for the bonding pads. The crystal structure consists of the metal atoms WSe2 flakes were exfoliated from bulk material sup- encapsulated between two layers of sulfur/selenium plied by Nanosurf onto a stack of polymer layers on a chalcogenide atoms. The bonding within a monolayer sacrificial silicon substrate. Suitable flakes were identi- is strong while the bonding between monolayers is fied under an optical microscope.
    [Show full text]
  • Flexible, Semi-Transparent Ultrathin Solar Cells 9 March 2014
    Flexible, semi-transparent ultrathin solar cells 9 March 2014 At least since the Nobel Prize in physics was awarded in 2010 for creating graphene, the "two dimensional crystals" made of carbon atoms have been regarded as one of the most promising materials in electronics. In 2013, graphene research was chosen by the EU as a flagship- project, with a funding of one billion euros. Graphene can sustain extreme mechanical strain and it has great opto-electronic properties. With graphene as a light detector, optical signals can be transformed into electric pulses on extremely short timescales. For one very similar application, however, graphene is not well suited for building solar cells. "The electronic states in graphene are not very practical for creating photovoltaics", says Thomas This is a microscope photograph of WSe2-samples, Mueller. Therefore, he and his team started to look connected to electrodes. Credit: TU Vienna for other materials, which, similarly to graphene, can arranged in ultrathin layers, but have even better electronic properties. A lot of research has been done on graphene The material of choice was tungsten diselenide: It recently—carbon flakes, consisting of only one layer consists of one layer of tungsten atoms, which are of atoms. As it turns out, there are other materials connected by selenium atoms above and below the too which exhibit remarkable properties if they are tungsten plane. The material absorbs light, much arranged in a single layer. One of them is tungsten like graphene, but in tungsten diselenide, this light diselenide, which could be used for photovoltaics. can be used to create electrical power.
    [Show full text]
  • ACS Division of Analytical Chemistry
    ANYL DIVISION OF ANALYTICAL CHEMISTRY P. Bohn and M. Bush, Program Chairs SUNDAY MORNING Section A Placeholder Low-Cost & Open-Source Analytical Chemistry J. P. Grinias, Organizer, Presiding 8:00 . Enabling Real-Time Processing of High-Volume Electrochemical Measurements via Open Source Software. N. Arroyo 8:20 . Open-Source Data Acquisition Devices for Chromatographic Instrumentation. S.W. Foster, E.W. Constans, J.P. Grinias 8:40 . Silicon photomultiplier as a low-cost fluorescence detector for capillary electrophoresis. B. Petersen, N.L. Allbritton 9:00 . Sensitive, selective, and quantitative copper sensor using click-chemistry with gold nanoparticles.. R.M. Cary, I. Monroe, j. holbrook, O. Hess, S. Unser, L. Sagle 9:20 . Glucose Responding Fluorescent Microneedle for An Affordable Continuous Glucose Monitoring. J. Kim, H. YIm, J. Park, H. Choi, B. Lee, S. Lee, M. Lee 9:40 Intermission. 10:00 . Low cost paper-based immunoassays for infectious disease diagnostics. K. Hamad- Schifferli 10:20 . Strength in numbers: A library of chemical color tests improves presumptive identification of illicit drugs and cutting agents.. T. Lockwood, B. Ray, G. Scott, M. Lieberman 10:40 . Chemical fingerprinting of carboxylate anions on low-cost paper supports. Y. Xu, M. Bonizzoni 11:00 . An Analysis of the Quality of Beta-Lactam Antibiotics collected in Nepal. W. Lewis, M. Benjamin 11:20 . Open-access resources for the teaching of analytical chemistry. D.T. Harvey 11:40 . Open-source analytical chemistry in the laboratory and the classroom. J.P. Grinias, J.A. Naese, J. Emig Section B Placeholder Active Learning in the Undergraduate Analytical Chemistry Curriculum (Invited) M.
    [Show full text]
  • 'Mind the Gap' Between Atomically Thin Materials 24 December 2014, by Walt Mills
    'Mind the gap' between atomically thin materials 24 December 2014, by Walt Mills layer down to the graphene layer, they encountered a surprising amount of resistance. About half of the resistance was caused by the gap, which introduced a large barrier, about 1 electron volt, to the electrons trying to move between layers. This energy barrier could prove useful in designing next generation electronic devices, such as vertical tunneling field effect transistors, said Robinson. The interest in this type of material arose with the discovery of methods to make single layer graphite. Colorized TEM image of tungsten disulfide triangles The Penn State researchers use a more scalable (black) growing on graphene substrate (green). Credit: method than early graphene makers—chemical UT Dallas/Penn State vapor deposition—to deposit a single layer of crystalline tungsten diselenide on top of a few layers of graphene grown from silicon carbide. When it comes to engineering single-layer atomic Although graphene research exploded in the last structures, "minding the gap" will help researchers decade, many similar solids exist that can combine create artificial electronic materials one atomic to create entirely new artificial materials with layer at a time, according to a team of materials unimaginable properties. scientists. The researchers discovered that the tungsten The gap is a miniscule vacuum that researchers in diselenide layer grew in perfectly aligned triangular Penn State's Center for 2-Dimensional and islands 1 to 3 microns in size that slowly coalesced Layered Materials believe is an energy barrier into a single crystal up to 1 centimeter square. They keeping electrons from easily crossing from one reported their results in Nano Letters.
    [Show full text]
  • United States Patent (19) (11) 4,208,474 Jacobson Et Al
    United States Patent (19) (11) 4,208,474 Jacobson et al. 45) Jun. 17, 1980 (54 CELL CONTAINING ALKALI METAL ANODE, CATHODE AND ALKALI OTHER PUBLICATIONS METAL-METALCHALCOGENEDE Hellstrom et al, Phase Relations and Charge Transport COMPOUND SOLD ELECTROLYTE in Ternary Aluminum Sulfides, Extended Abstracts, vol. 78-1, Electrochemical Soc., pp. 393-395, May 75) Inventors: Allan J. Jacobson, Princeton; 1978. Bernard G. Sibernagel, Scotch Plains, both of N.J. Primary Examiner-Donald L. Walton Attorney, Agent, or Firm-Kenneth P. Glynn 73) Assignee: Exxon Research & Engineering Co., Florham Park, N.J. 57 ABSTRACT A novel electrochemical cell is disclosed which con (21) Appl. No.: 974,021 tains an alkali metal anode, an electrolyte and a chalco genide cathode wherein the electrolyte is a solid com 22 Filed: Dec. 28, 1978 position containing an electrolytically active amount of 5ll int. Cl’............................................. HOM 6/18 one or more compounds having the formula: 52 U.S. C. ..................................... 429/191; 429/218 58 Field of Search ................................ 429/19, 218 56) References Cited wherein A is an alkali metal, wherein B is an element U.S. PATENT DOCUMENTS selected from the group consisting of boron and alumi 3,751,298 8/1973 Senderoff............................. 136/6 F num, wherein C is a chalcogen, wherein x and y are 3,791,867 2/1974 Broadhead et al. ................. 36/6 F each greater than zero and wherein x-3y=4. A pre 3,864,167 2/1975 Broadhead et al. ....... ... 136/6 LN 3,877,984 4/1975 Werth .................................. 136/6 F ferred compound is LiBS2. A preferred cell is one hav 3,925,098 12/1975 Saunders ......
    [Show full text]