DOCSLIB.ORG

Thesis Bojian Xu

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Thesis Bojian Xu CHARGE TRANSPORT IN NANOSCALE LATERAL AND VERTICAL ORGANIC SEMICONDUCTOR DEVICES Bojian Xu The research described within this thesis was carried out in the NanoElectronics Group at the MESA+ Institute for Nanotechnology at the University of Twente, Enschede, The Netherlands. The NWO-nano (STW) program, grant no. 11470, and the China Scholarship Council program, grant no. 201206090154 financially supported this research. Thesis committee members Chairman & secretary: Prof.dr. P.M.G. Apers University of Twente Promotor: Prof.dr.ir. W.G. van der Wiel University of Twente Other members: Prof.dr. P.A. Bobbert University of Twente Prof.dr.ir. G. Koster University of Twente Dr.ir. M.P. de Jong University of Twente Prof.dr. P.W.M. Blom Max Planck Institute for Polymer Research, Mainz Prof.dr. B.J. Ravoo University of Münster Title: Charge transport in nanoscale lateral and vertical organic semiconductor devices Author: Bojian Xu Cover design: Ximing Fu Copyright © 2017 by Bojian Xu, Enschede, The Netherlands. Printed by Gildeprint, Enschede, The Netherlands, 2017. ISBN: 978-90-365-4286-9 DOI: 10.3990/1.9789036542869 CHARGE TRANSPORT IN NANOSCALE LATERAL AND VERTICAL ORGANIC SEMICONDUCTOR DEVICES DISSERTATION to obtain the degree of doctor at the University of Twente, on the authority of the rector magnificus, prof.dr. T.T.M. Palstra, on account of the decision of the graduation committee, to be publicly defended on Friday March 10th 2017 at 14.45 by Bojian Xu born on March 14th, 1987 in Jiangsu, China This dissertation has been approved by: Promotor: Prof.dr.ir. W.G. van der Wiel This thesis is dedicated to my family. Contents 1 Introduction and motivation ......................................................................................... 1 1.1 Motivation ............................................................................................................ 1 1.2 Thesis outline ....................................................................................................... 2 References ......................................................................................................................... 4 2 Theoretical background ................................................................................................. 6 2.1 Basic concepts of electrical conduction ............................................................... 6 2.2 Introduction to organic electronics ...................................................................... 9 2.2.1 Molecular orbitals, energy bands/levels, band conduction and hopping conduction ..................................................................................................................... 9 2.2.2 Why organic materials? ................................................................................. 13 2.2.3 Subfields of organic electronics ..................................................................... 14 2.3 Organic field-effect transistors ........................................................................... 16 References ....................................................................................................................... 25 3 Nanoindentation with accurate positioning........................................................... 32 3.1 Introduction and motivation .............................................................................. 32 3.2 Nanoindentation ................................................................................................ 35 3.3 Device fabrication .............................................................................................. 37 3.4 Nanoindentation results and discussion ............................................................ 38 3.4.1 Nanoindentation using conventional working modes of the Veeco Dimension 3100 AFM ..................................................................................................................... 38 3.4.2 Nanoindentation with accurate positioning using the “point-and-shoot” function …………………………………………………………………………………………………………………..46 3.5 Summary and outlook ........................................................................................ 52 References ....................................................................................................................... 54 4 DXP lateral field-effect transistors ............................................................................ 56 4.1 Introduction and motivation .............................................................................. 56 4.2 Experiments and results ..................................................................................... 56 4.3 Summary and outlook ........................................................................................ 66 i References ....................................................................................................................... 67 5 Charge transport in nanoscale vertical P3HT pillar devices ............................ 69 5.1 Introduction and motivation .............................................................................. 69 5.2 Device fabrication .............................................................................................. 71 5.3 Electrical transport measurements .................................................................... 74 5.4 Simulation of the temperature dependence ..................................................... 81 5.5 Summary and outlook ........................................................................................ 86 References ....................................................................................................................... 87 6 Vertical P3HT field-effect transistors ....................................................................... 91 6.1 Introduction and motivation .............................................................................. 91 6.2 Device fabrication .............................................................................................. 91 6.3 Electrical transport measurements .................................................................... 94 6.4 ATLAS device simulations ................................................................................... 96 6.5 Summary and outlook ...................................................................................... 111 References ..................................................................................................................... 112 7 Conclusions and outlook ............................................................................................ 113 References ..................................................................................................................... 115 Summary ................................................................................................................................. 116 Samenvatting ......................................................................................................................... 119 Acknowledgements………………………………………………………………………………………..123 ii Chapter 1: Introduction and motivation Chapter 1 Introduction and motivation 1.1 Motivation Organic semiconductor materials are being intensely studied because of their extensive application in low-cost [1], flexible [2], biocompatible [3] electronic and spintronics [4] devices. Examples include organic field-effect transistors (OFETs) [5], organic light-emitting diodes (OLEDs) [6], and organic spin valves (OSVs) [7]. In this thesis research, we have investigated charge transport in organic semiconductor devices. Specifically, we focused on two organic materials, N, N’-bis(2,6-dimethylphenyl)-perylene-3,4,9,10-tetracarboxylic diimide (DXP) and poly(3-hexylthiophene) (P3HT), in different device configurations. DXP is a molecular organic semiconductor. It can be assembled into molecular wires when the molecules are inserted in the nanopores of zeolite L crystals [8, 9]. Electrical transport in the molecular wires is expected to have distinctive properties due to the spatial constriction of the molecular wires [10]. To investigate the electrical transport of the DXP- loaded zeolite L crystals in multiple experimental instruments, we planned to embed the crystals into devices. Hence, we designed a device fabrication process based on the nanoindentation technique using atomic force microscope (AFM). In the fabrication process, a critical step was to execute the nanoindentation precisely and only on top of the crystals with ~150 - 300 nm diameter. Therefore, it was necessary to carefully verify the positioning properties of the nanoindentation technique. Lateral field-effect transistors are suitable for investigation of the electrical transport properties in organic semiconductors [11]. In addition, one can integrate on-chip coplanar waveguides so that magnetic resonance experiments can be performed to study spin dynamics [12, 13]. By investigating lateral FETs with channel lengths similar to the lengths (sub-100 to hundreds of nm) of the molecular wires in the zeolites mentioned above, we could compare results between the lateral devices and the DXP-loaded crystals. Hence, apart from the DXP-molecular-wire devices, we also investigated the charge transport properties of the DXP lateral field-effect transistors with 100 nm channel length. There are more reasons to investigate OFETs with a short channel length. It has been reported that decreasing the channel length can increase the cut-off frequency of devices
Load more

Recommended publications
  • High-Throughput Investigation of the Geometry and Electronic Structures
    Subscriber access provided by FRITZ HABER INST DER MPI Article High-Throughput Investigation of the Geometry and Electronic Structures of Gas-Phase and Crystalline Polycyclic Aromatic Hydrocarbons Bohdan Schatschneider, Stephen Monaco, Jian-Jie Liang, and Alexandre Tkatchenko J. Phys. Chem. C, Just Accepted Manuscript • DOI: 10.1021/jp5064462 • Publication Date (Web): 07 Aug 2014 Downloaded from http://pubs.acs.org on August 12, 2014 Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
    [Show full text]
  • Chemical Stability and Performance Influence of Choice Substituents and Core Conjugation of Organic Semiconductors
    University of Massachusetts Amherst ScholarWorks@UMass Amherst Doctoral Dissertations Dissertations and Theses March 2019 CHEMICAL STABILITY AND PERFORMANCE INFLUENCE OF CHOICE SUBSTITUENTS AND CORE CONJUGATION OF ORGANIC SEMICONDUCTORS Jack Ly University of Massachusetts Amherst Follow this and additional works at: https://scholarworks.umass.edu/dissertations_2 Part of the Polymer and Organic Materials Commons, Polymer Science Commons, and the Semiconductor and Optical Materials Commons Recommended Citation Ly, Jack, "CHEMICAL STABILITY AND PERFORMANCE INFLUENCE OF CHOICE SUBSTITUENTS AND CORE CONJUGATION OF ORGANIC SEMICONDUCTORS" (2019). Doctoral Dissertations. 1516. https://doi.org/10.7275/13323135 https://scholarworks.umass.edu/dissertations_2/1516 This Open Access Dissertation is brought to you for free and open access by the Dissertations and Theses at ScholarWorks@UMass Amherst. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of ScholarWorks@UMass Amherst. For more information, please contact [email protected]. CHEMICAL STABILITY AND PERFORMANCE INFLUENCE OF CHOICE SUBSTITUENTS AND CORE CONJUGATION OF ORGANIC SEMICONDUCTORS A Dissertation Presented By JACK THANH LY Submitted to the Graduate School of the University of Massachusetts Amherst in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY February 2019 Polymer Science and Engineering © Copyright by Jack Thanh Ly 2019 All Rights Reserved CHEMICAL STABILITY AND PERFORMANCE INFLUENCE OF CHOICE
    [Show full text]
  • Dr. Jordy Bouwman
    Dr. Jordy Bouwman Email: [email protected] Website: https://www.strw.leidenuniv.nl/~bouwman EDUCATION Leiden University Leiden, the Netherlands Ph.D., Natural Sciences / Astronomy October 2010 Thesis research with Prof. Dr. H.V.J. Linnartz titled: “Spectroscopy and Chemistry of Interstellar Ice Analogues”. Free University Amsterdam Amsterdam, the Netherlands M.Sc., Chemistry – Laser Sciences February 2006 Thesis title: “A new experimental setup for cavity ringdown spectroscopy on transient species”. University of Applied Sciences Rijswijk Rijswijk, the Netherlands B.Eng., cum laude, Applied Physics February 2004 Thesis title: “High-resolution infrared absorption spectroscopy on weakly bound ionic complexes”. PERSONAL GRANTS Netherlands Organisation for Scientific Research Leiden, the Netherlands Vidi Research Grant May 2017 An €800.000 personal grant for conducting three years of independent research at Leiden University, Leiden, the Netherlands. Title of grant proposal: “Hydrocarbon chemistry under exotic conditions: the case of (exo)planetary atmospheres” Netherlands Organisation for Scientific Research Nijmegen, the Netherlands Veni Research Grant July 2013 A €250.000 personal grant for conducting three years of independent research at the free electron laser FELIX at Radboud University, Nijmegen, the Netherlands. OTHER GRANTS National Aeronautics and Space Administration Berkeley (CA), USA NASA Planetary Atmospheres Program 2012 Successfully prepared and developed a $450.000 grant proposal to investigate chemical kinetics and reaction products of a number of radical-neutral reactions at Lawrence Berkeley National Laboratory. RESEARCH EXPERIENCE Universiteit Leiden Leiden, the Netherlands Non-tenure-track Assistant Professor Nov. 2016 – Present Combined experimental and computational investigations to the influence of the shape and symmetry of polyaromatic species on the appearance of the interstellar aromatic infrared bands.
    [Show full text]
  • Structure-Function Relationships in Organic Charge-Transfer
    STRUCTURE-FUNCTION RELATIONSHIPS IN ORGANIC CHARGE-TRANSFER COMPLEXES BY KATELYN PATRICIA GOETZ A Dissertation Submitted to the Graduate Faculty of WAKE FOREST UNIVERSITY GRADUATE SCHOOL OF ARTS AND SCIENCES in Partial Fulfillment of the Requirements for the Degree of DOCTOR OF PHILOSOPHY Physics May 2016 Winston-Salem, North Carolina Approved By: Oana D. Jurchescu, Ph.D., Advisor Laurie E. McNeil, Ph.D., Chair Natalie A. W. Holzwarth, Ph.D. George E. Matthews, Ph.D. Richard T. Williams, Ph.D. Acknowledgments Many people have been invaluable in the completion of my two Wake Forest University degrees. First and foremost, I would like to thank my advisor, Dr. Oana Jurchescu. She has been a great mentor in my academic career, and was always available to talk about science and life. I do not believe I would have had the opportunities I had during my graduate career if I had pursued it elsewhere. Thanks also to the entire Wake Forest Physics Department for inspiring and teaching me, and also for being living examples of what a good research career is and can be. I would especially like to thank Dr. Keith Bonin for (possibly unknowingly) providing the push I needed to major in physics by teaching an enthusiastic and interesting electronics class. Dr. Eric Carlson also deserves a thank you for organizing the society of physics students chapter in our department. I have very much enjoyed participating in science outreach through demo days at Sci Works and work with K-12 classrooms in the area. Eric Chapman has been invaluable throughout my nine years in the department for technical help and good conversations.
    [Show full text]
  • Structural and Quantum Chemical Analysis of Exciton Coupling in Homo- and Heteroaggregate Stacks of Merocyanines
    ARTICLE Received 6 May 2016 | Accepted 18 Aug 2016 | Published 29 Sep 2016 DOI: 10.1038/ncomms12949 OPEN Structural and quantum chemical analysis of exciton coupling in homo- and heteroaggregate stacks of merocyanines David Bialas1, Andre´ Zitzler-Kunkel1, Eva Kirchner1, David Schmidt1 & Frank Wu¨rthner1 Exciton coupling is of fundamental importance and determines functional properties of organic dyes in (opto-)electronic and photovoltaic devices. Here we show that strong exciton coupling is not limited to the situation of equal chromophores as often assumed. Quadruple dye stacks were obtained from two bis(merocyanine) dyes with same or different chromo- phores, respectively, which dimerize in less-polar solvents resulting in the respective homo- and heteroaggregates. The structures of the quadruple dye stacks were assigned by NMR techniques and unambiguously confirmed by single-crystal X-ray analysis. The hetero- aggregate stack formed from the bis(merocyanine) bearing two different chromophores exhibits remarkably different ultraviolet/vis absorption bands compared with those of the homoaggregate of the bis(merocyanine) comprising two identical chromophores. Quantum chemical analysis based on an extension of Kasha’s exciton theory appropriately describes the absorption properties of both types of stacks revealing strong exciton coupling also between different chromophores within the heteroaggregate. 1 Universita¨tWu¨rzburg, Institut fu¨r Organische Chemie and Center for Nanosystems Chemistry, Am Hubland, 97074 Wu¨rzburg, Germany. Correspondence and requests for materials should be addressed to F.W. (email: [email protected]). NATURE COMMUNICATIONS | 7:12949 | DOI: 10.1038/ncomms12949 | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | DOI: 10.1038/ncomms12949 he molecular exciton theory pioneered by Kasha1 and by X-ray analysis.
    [Show full text]
  • Infrared Action Spectroscopy of Doubly Charged Pahs and Their Contribution to the Aromatic Infrared Bands S
    A&A 648, A61 (2021) Astronomy https://doi.org/10.1051/0004-6361/202039744 & © ESO 2021 Astrophysics Infrared action spectroscopy of doubly charged PAHs and their contribution to the aromatic infrared bands S. Banhatti1, J. Palotás2, P. Jusko3, B. Redlich2, J. Oomens2,4, S. Schlemmer1, and S. Brünken2 1 I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany 2 Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7, 6525ED Nijmegen, The Netherlands e-mail: [email protected] 3 Max Planck Institute for Extraterrestrial Physics, Gießenbachstraße 1, 85748 Garching, Germany 4 van ’t Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 908, 1098XH Amsterdam, The Netherlands Received 22 October 2020 / Accepted 14 February 2021 ABSTRACT The so-called aromatic infrared bands (AIBs) are attributed to emission of polycyclic aromatic hydrocarbons (PAHs). The observed variations toward different regions in space are believed to be caused by contributions of different classes of PAH molecules, that is to say with respect to their size, structure, and charge state. Laboratory spectra of members of these classes are needed to compare them to observations and to benchmark quantum-chemically computed spectra of these species. In this paper we present the experimental infrared (IR) spectra of three different PAH dications, naphthalene2+, anthracene2+, and phenanthrene2+, in the vibrational fingerprint 1 region 500–1700 cm− . The dications were produced by electron impact ionization of the vapours with 70 eV electrons, and they remained stable against dissociation and Coulomb explosion. The vibrational spectra were obtained by IR predissociation of the PAH2+ complexed with neon in a 22-pole cryogenic ion trap setup coupled to a free-electron infrared laser at the Free-Electron Lasers for Infrared eXperiments (FELIX) Laboratory.
    [Show full text]
  • A Method for Producing an Organic Field Effect Transistor and an Organic Field Effect Transistor
    (19) TZZ _¥¥_T (11) EP 2 797 133 A1 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: (51) Int Cl.: 29.10.2014 Bulletin 2014/44 H01L 51/05 (2006.01) H01L 51/10 (2006.01) H01L 51/52 (2006.01) (21) Application number: 13164959.2 (22) Date of filing: 23.04.2013 (84) Designated Contracting States: • Kleemann, Hans AL AT BE BG CH CY CZ DE DK EE ES FI FR GB 01187 Dresden (DE) GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO • Lüssem, Björn PL PT RO RS SE SI SK SM TR 01127 Dresden (DE) Designated Extension States: •Leo,Karl BA ME 01219 Dresden (DE) (71) Applicants: (74) Representative: Bittner, Thomas L. • Novaled GmbH Boehmert & Boehmert 01307 Dresden (DE) Anwaltspartnerschaft mbB • Technische Universität Dresden Patentanwälte Rechtsanwälte 01062 Dresden (DE) Pettenkoferstrasse 20-22 80336 München (DE) (72) Inventors: •Günther,Alrun 01159 Dresden (DE) (54) A method for producing an organic field effect transistor and an organic field effect transistor (57) The present disclosure relates to a method for producing an organic field effect transistor, the method comprising steps of providing a gate electrode (1) and a gate insulator (2) assigned to the gate electrode (1) for electrical insulation on a substrate, depositing a first or- ganic semiconducting layer (3) on the gate insulator (2), generating a first electrode (4) and an electrode insulator (5) assigned to the first electrode (4) for electrical insu- lation, depositing a second organic semiconducting layer (6) on the first organic semiconducting layer (3) and the electrode insulator
    [Show full text]
  • Organic Semiconductors for Device Applications: Current Trends and Future Prospects
    DOI 10.1515/polyeng-2013-0267 J Polym Eng 2014; 34(4): 279–338 Review Shamim Ahmad* Organic semiconductors for device applications: current trends and future prospects Abstract: With the rich experience of developing silicon 1 Introduction devices over a period of the last six decades, it is easy to assess the suitability of a new material for device appli- A wide range of organic semiconductors (OS) are cur- cations by examining charge carrier injection, transport, rently being explored extensively for their applications and extraction across a practically realizable architecture; in organic electronics (OE) primarily due to the growing surface passivation; and packaging and reliability issues need of substituting silicon (Si) with some alternative besides the feasibility of preparing mechanically robust cost-effective materials offering relatively simpler and wafer/substrate of single-crystal or polycrystalline/ commercially viable technologies [1–7] at least in some amorphous thin films. For material preparation, param- niche areas. Based on the recent developments in the area eters such as purification of constituent materials, crystal of OS, processes involving printing of semiconductor, con- growth, and thin-film deposition with minimum defects/ ductor, and dielectric patterns on a variety of hard as well disorders are equally important. Further, it is relevant to as flexible substrates are fast emerging as part of a com- know whether conventional semiconductor processes, mercially viable technology for the upcoming OE devices.
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 9.249,071 B2 Strauss Et Al
    US009249071B2 (12) United States Patent (10) Patent No.: US 9.249,071 B2 Strauss et al. (45) Date of Patent: Feb. 2, 2016 (54) MODIFIED POLYAROMATIC Bravo, “New Methods of Free-Radical Periluoroalkylation of Aro HYDROCARBONS AND matics and Alkenes. Absolute Rate Constants and Partial Rate Factors POLYHETEROCYCLICS FOR for the Homolytic Aromatic Substitution by n-Perfluorobutyl Radi OPTOELECTRONICS cal”, J. Org. Chem., 21:7128-7136 (1997). Cowell, “Fluoroalkylation of Aromatic Compounds”, Journal of (71) Applicant: Colorado State University Research Fluorine Chemistry, 17:345-356 (1981). Foundation, Fort Collins, CO (US) Freskos, "A Convenient Synthesis of Pentafluoroethyl-substituted Aromatics”, Journal: Synthetic communications, 18(9):965-972 (72) Inventors: Steven H. Strauss, Fort Collins, CO (1988). (US): Olga V. Boltalina, Fort Collins, Hosokawa et al., “Synthesis of Beta-Trifluoromethylnaphthalene CO (US); Igor V. Kuvychko, Fort Derivatives'. Gov't Industrial Research Institute, 2:383-386 (1972). Collins, CO (US) (With English Abstract). Hosokawa et al., “Synthesis of (Trifluoromethyl)naphthalenes', (73) Assignee: Colorado State University Research Gov't Industrial Research Institute, 11:1791-1793 (1976). (With Foundation, Fort Collins, CO (US) English Abstract). Hosokawa et al., “Synthesis Bis(trifluoromethyl)naphthalenes', (*) Notice: Subject to any disclaimer, the term of this Gov't Industrial Research Institute, 8: 1163-1167 (1977). (With patent is extended or adjusted under 35 English Abstract). U.S.C. 154(b) by 0 days. Hosokawa et al., “Synthesis of Substituted (Trifluoromethyl)naphthalenes', Gov't Industrial Research Institute, (21) Appl. No.: 14/174,780 2:294-296 (1979). (With English Abstract). Krespan et al., “Bis-(polyfluoroalkyl)-acetylenes. II. (22) Filed: Feb. 6, 2014 Bicyclooctatrienes Through 1,4-Addition of Bis-(polyfluoroalkyl)- acetylenes to Aromatic Rings'.
    [Show full text]
  • Unraveling Efficiency-Limiting Processes in Organic Solar Cells By
    Unraveling Efficiency-Limiting Processes in Organic Solar Cells by Ultrafast Spectroscopy – Impact of Chemical Structure and Morphology on Photophysics and Efficiency Dissertation zur Erlangung des Grades ‚Doktor der Naturwissenschaften‚ im Promotionsfach Chemie am Fachbereich Chemie, Pharmazie und Geowissenschaften der Johannes Gutenberg-Universität in Mainz Dominik Werner Gehrig geb. in Karlstadt am Main Mainz, den 30.06.2015 1. Berichterstatter: Prof. Dr. Frédéric Laquai 2. Berichterstatter: Prof. Dr. Thomas Basché Tag der mündlichen Prüfung: 18.11.2015 I hereby declare that I wrote this dissertation submitted without any unauthorized external assistance and used only sources acknowledged in the work. All textual passages which are appropriated verbatim or paraphrased from published and unpublished texts as well as all information obtained from oral sources are duly indicated and listed in accordance with bibliographical rules. In carrying out this research, I complied with the rules of standard scientific practice as formulated in the statutes of the Johannes Gutenberg- University Mainz to insure standard scientific practice. Dominik Gehrig I Summary This work is dedicated to the investigation of the photophysical processes that occur in photovoltaic blends of electron-donating and -accepting materials. As electron donors the copolymer PBDTTT-C which consists of benzodithiophene and thienothiophene units and the small molecule p-DTS(FBTTh2)2 that contains silicon-bridged dithiophene, fluorinated benzothiadiazole and bithiophene are used. As electron-accepting material a planar 3,4:9,10-perylenetetracarboxylic acid diimide (PDI) derivative and different fullerene derivatives are employed. PDIs are regarded as a promising alternative to fullerenes due to the tunable structural, optical, and electronic properties with elaborated chemical synthesis.
    [Show full text]
  • Petroleum Reference Standards
    petroleum Chiron was established in 1983 by Dr. Jon Eigill Johansen in Trondheim, Norway and started with the development and production of biomarkers for use in the search for oil in the North Sea. Chiron has therefore been involved in the preparation of steroid and triterpanoid (hopane) reference materials used in the petroleum industry for over 30 years, and possess a unique experience in this field. These compounds are found in petroleum and sediments. Hopanes are in fact the second largest group of natural products on earth, surpassed only by cellulose. This type of compound changes its chemical structure over time and maturation. They have traditionally been used in petroleum exploration, but in recent years have been increasingly used for forensic analysis, for example in the investigation of oil spills. Chiron works with major oil companies, institutions, private laboratories, universities and hospitals in this area, and is currently the only producer of a large range of oil exploration reference materials. Join our PETROLEUM BIOMARKER group on LinkedIn! The Petroleum Biomarker Group Chiron AS Stiklestadvn. 1 N-7041 Trondheim Norway Phone No.: +47 73 87 44 90 Fax No.: +47 73 87 44 99 E-mail: [email protected] Website: www.chiron.no Org. No.: NO 967 607 657 MVA CONTENTS Aliphatic alkanes (paraffins) 1 Diterpenoid compounds 16 Deuterated n-alkanes (internal standards) 1-2 C25 Terpanes 16 Fluoro-n-alkanes (internal standard) 2 Steranes (Tetracyclic compounds) 16 n-Alkanes 2-3 Sterane internal standards 16-17 2-Methylalkanes (isoalkanes)
    [Show full text]
  • Investigation of Exciton Transport in Crystalline Thin-Films of the Organic
    Investigation of exciton transport in crystalline thin-films of the organic semiconductor di-indeno-perylene using photoluminescence analyses A. K. Topczak,1 T. Roller,2 B. Engels,1 W. Br¨utting,3 J. Pflaum1,4a 1Julius-Maximillians University, Am Hubland, 97074 W¨urzburg Germany 2University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany 3University of Augsburg, Universit¨atsstrae 1, 86159 Augsburg, Germany 4ZAE Bayern, Am Hubland, 97074 W¨urzburg Germany (Dated: January 15, 2021) The exciton transport in the prototypical organic semiconductor Di-Indeno-Perylene (DIP) has been investigated by means of photoluminescence (PL) quenching and interpreted by an advanced exciton diffusion model including interference effects, quencher penetration as well as non-perfect exciton quenching. X-ray diffraction revealed a correlation between the exciton diffusion length of about 90 nm and the structural coherence length of the DIP layers. Temperature dependent studies in a range of 5 - 300 K indicated an incoherent exciton transport above 80 K at activation energies of 10 - 20 meV related to the thickness dependent gradient of exciton density. Below 80 K a coherent exciton transport can be observed by the reduced phonon-interaction at cryogenic temperatures. This manuscript is a pre-final version. By their progressively improving power conversion ef- studies. For this purpose, DIP samples were prepared by ficiency, organic thin film photovoltaic cells pave their organic molecular beam epitaxy on cleaned glass slides. way towards first applications4. In organic bilayer pho- The resulting film structure of the samples was ana- tovoltaic cells, the competition between exciton diffusion lyzed in detail by X-ray diffraction at various geometries.
    [Show full text]