151
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Huang YL, Wruss E, Egger DA, Kera S, Ueno N, Saidi WA, Bucko T, Wee ATS, Zojer E. Understanding the adsorption of CuPc and ZnPc on noble metal surfaces by combining quantum-mechanical modelling and photoelectron spectroscopy. Molecules 2014; 19:2969-92. [PMID: 24609018 PMCID: PMC6271497 DOI: 10.3390/molecules19032969] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 02/24/2014] [Accepted: 02/26/2014] [Indexed: 11/16/2022] Open
Abstract
Phthalocyanines are an important class of organic semiconductors and, thus, their interfaces with metals are both of fundamental and practical relevance. In the present contribution we provide a combined theoretical and experimental study, in which we show that state-of-the-art quantum-mechanical simulations are nowadays capable of treating most properties of such interfaces in a quantitatively reliable manner. This is shown for Cu-phthalocyanine (CuPc) and Zn-phthalocyanine (ZnPc) on Au(111) and Ag(111) surfaces. Using a recently developed approach for efficiently treating van der Waals (vdW) interactions at metal/organic interfaces, we calculate adsorption geometries in excellent agreement with experiments. With these geometries available, we are then able to accurately describe the interfacial electronic structure arising from molecular adsorption. We find that bonding is dominated by vdW forces for all studied interfaces. Concomitantly, charge rearrangements on Au(111) are exclusively due to Pauli pushback. On Ag(111), we additionally observe charge transfer from the metal to one of the spin-channels associated with the lowest unoccupied π-states of the molecules. Comparing the interfacial density of states with our ultraviolet photoelectron spectroscopy (UPS) experiments, we find that the use of a hybrid functionals is necessary to obtain the correct order of the electronic states.
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Affiliation(s)
- Yu Li Huang
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore.
| | - Elisabeth Wruss
- Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria.
| | - David A Egger
- Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria.
| | - Satoshi Kera
- Graduate School of Advanced Integration Science, Chiba University, 1- 33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.
| | - Nobuo Ueno
- Graduate School of Advanced Integration Science, Chiba University, 1- 33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan.
| | - Wissam A Saidi
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, 1249 Benedum Hall, Pittsburgh, PA 15261, USA.
| | - Tomas Bucko
- Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University, Mlynska Dolina, SK-84215 Bratislava, Slovakia.
| | - Andrew T S Wee
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore.
| | - Egbert Zojer
- Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria.
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152
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Niederhausen J, Duhm S, Heimel G, Bürker C, Xin Q, Wilke A, Vollmer A, Schreiber F, Kera S, Rabe JP, Ueno N, Koch N. Seleno groups control the energy-level alignment between conjugated organic molecules and metals. J Chem Phys 2014; 140:014705. [DOI: 10.1063/1.4858856] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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153
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Cornil D, Van Regemorter T, Beljonne D, Cornil J. Work function shifts of a zinc oxide surface upon deposition of self-assembled monolayers: a theoretical insight. Phys Chem Chem Phys 2014; 16:20887-99. [DOI: 10.1039/c4cp02811b] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have investigated at the DFT level the way the work function of ZnO is affected upon deposition of self-assembled monolayers made of 4-tert-butylpyridine and various benzoic acids.
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Affiliation(s)
- D. Cornil
- Laboratory for Chemistry of Novel Materials
- University of Mons (UMons)
- Mons 7000, Belgium
| | - T. Van Regemorter
- Laboratory for Chemistry of Novel Materials
- University of Mons (UMons)
- Mons 7000, Belgium
| | - D. Beljonne
- Laboratory for Chemistry of Novel Materials
- University of Mons (UMons)
- Mons 7000, Belgium
| | - J. Cornil
- Laboratory for Chemistry of Novel Materials
- University of Mons (UMons)
- Mons 7000, Belgium
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154
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Chilukuri B, Mazur U, Hipps KW. Effect of dispersion on surface interactions of cobalt(ii) octaethylporphyrin monolayer on Au(111) and HOPG(0001) substrates: a comparative first principles study. Phys Chem Chem Phys 2014; 16:14096-107. [DOI: 10.1039/c4cp01762e] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Implication of dispersion interactions on geometric, adsorption and electronic properties of porphyrin monolayer on conductive surfaces using density functional theory.
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Affiliation(s)
| | - Ursula Mazur
- Department of Chemistry
- Washington State University
- Pullman, USA
| | - K. W. Hipps
- Department of Chemistry
- Washington State University
- Pullman, USA
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155
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Tronnier A, Metz S, Wagenblast G, Muenster I, Strassner T. Blue phosphorescent nitrile containing C^C* cyclometalated NHC platinum(ii) complexes. Dalton Trans 2014; 43:3297-305. [DOI: 10.1039/c3dt53264j] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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156
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Gallego JM, Ecija D, Martín N, Otero R, Miranda R. An STM study of molecular exchange processes in organic thin film growth. Chem Commun (Camb) 2014; 50:9954-7. [PMID: 25035072 DOI: 10.1039/c4cc03656e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
PCBM molecules deposited on an exTTF layer grown on Au(111) exchange places with the exTTF molecules, expelling them to the outer surface, even at 150 K, when the surface diffusion of the exTTF molecules is completely frozen.
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Affiliation(s)
- José M. Gallego
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia)
- E-28049 Madrid, Spain
- Instituto de Ciencia de Materiales de Madrid
- CSIC
- E-28049 Madrid, Spain
| | - David Ecija
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia)
- E-28049 Madrid, Spain
| | - Nazario Martín
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia)
- E-28049 Madrid, Spain
- Dpto. de Química Orgánica
- Universidad Complutense de Madrid
- E-28040 Madrid, Spain
| | - Roberto Otero
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia)
- E-28049 Madrid, Spain
- Dpto. de Física de la Materia Condensada
- Universidad Autónoma de Madrid
- E-28049 Madrid, Spain
| | - Rodolfo Miranda
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia)
- E-28049 Madrid, Spain
- Dpto. de Física de la Materia Condensada
- Universidad Autónoma de Madrid
- E-28049 Madrid, Spain
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157
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Martínez JI, Abad E, Beltrán JI, Flores F, Ortega J. Barrier height formation in organic blends/metal interfaces: Case of tetrathiafulvalene-tetracyanoquinodimethane/Au(111). J Chem Phys 2013; 139:214706. [DOI: 10.1063/1.4836635] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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158
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Hofmann OT, Deinert JC, Xu Y, Rinke P, Stähler J, Wolf M, Scheffler M. Large work function reduction by adsorption of a molecule with a negative electron affinity: Pyridine on ZnO(101¯0). J Chem Phys 2013; 139:174701. [DOI: 10.1063/1.4827017] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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159
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Broch K, Gerlach A, Lorch C, Dieterle J, Novák J, Hinderhofer A, Schreiber F. Structure formation in perfluoropentacene:diindenoperylene blends and its impact on transient effects in the optical properties studied in real-time during growth. J Chem Phys 2013; 139:174709. [PMID: 24206324 DOI: 10.1063/1.4827868] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- K Broch
- Universität Tübingen, Institut für Angewandte Physik and LISA+, Auf der Morgenstelle 10, 72076 Tübingen, Germany
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160
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Nau S, Schulte N, Winkler S, Frisch J, Vollmer A, Koch N, Sax S, List EJW. Highly efficient color-stable deep-blue multilayer PLEDs: preventing PEDOT:PSS-induced interface degradation. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:4420-4424. [PMID: 23776150 DOI: 10.1002/adma.201300832] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 05/08/2013] [Indexed: 06/02/2023]
Abstract
Highly efficient and stable blue light emission is observed in novel copolymers that are produced from specially designed building blocks. A PEDOT:PSS-induced chemical degradation of the polymer light-emitting diodes (PLEDs) is identified at the interface, and it is found to be accompanied by a shift in the emission color. A method to prevent this highly undesirable interaction is presented.
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Affiliation(s)
- Sebastian Nau
- NanoTecCenter Weiz Forschungsgesellschaft mbH, Franz-Pichler Strasse 32, Weiz, Austria
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161
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Janghouri M, Mohajerani E, Amini MM, Safari N. Porphyrin doping of dichloride-bis(5,7-dichloroquinolin-8-olato)tin(IV) complex for electroluminescence. J PORPHYR PHTHALOCYA 2013. [DOI: 10.1142/s1088424613500132] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A method for obtaining red emission from an organic-light emitting diode has been developed by dissolving red and yellow dyes in a common solvent and thermally evaporating the mixture in a single furnace. Dichlorido-bis(5,7-dichloroquinolin-8-olato)tin(IV) complex ( Q2SnCl2 , Q = 5,7-dichloro-8-hydroxyquinoline) has been synthesized for using as a fluorescent material in organic light-emitting diodes (OLEDs). The electronic states HOMO (Highest Occupied Molecular Orbital)/LUMO (Lowest Occupied Molecular Orbital) energy levels explored by means of cyclic voltammetry measurements. A device with fundamental structure of ITO/PEDOT:PSS (55nm)/PVK (90nm)/ Q2SnCl2/Al (180nm) was fabricated and its electroluminescence performance at various thicknesses of light emitting layer (LEL) of Q2SnCl2 is reported. By following this step, an optimal thickness for the doping effect was also identified and explained. Finally a device with fundamental structure of ITO/PEDOT:PSS (55nm)/PVK (90nm)/meso-tetraphenylporphyrin (TPP): Q2SnCl2 (75nm)/ Al (180nm) was fabricated and its electroluminescence performance at various concentrations of dye has been investigated. It is shown that this new method is promising candidate for fabrication of low cost OLEDs at more homogeneous layer.
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Affiliation(s)
- Mohammad Janghouri
- Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 198393963113, Iran
| | - Ezeddin Mohajerani
- Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 198393963113, Iran
| | - Mostafa M. Amini
- Department of Chemistry, Shahid Beheshti University, G.C., Tehran 198393963113, Iran
| | - Naser Safari
- Department of Chemistry, Shahid Beheshti University, G.C., Tehran 198393963113, Iran
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162
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Valitova I, Amato M, Mahvash F, Cantele G, Maffucci A, Santato C, Martel R, Cicoira F. Carbon nanotube electrodes in organic transistors. NANOSCALE 2013; 5:4638-4646. [PMID: 23639944 DOI: 10.1039/c3nr33727h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The scope of this Minireview is to provide an overview of the recent progress on carbon nanotube electrodes applied to organic thin film transistors. After an introduction on the general aspects of the charge injection processes at various electrode-semiconductor interfaces, we discuss the great potential of carbon nanotube electrodes for organic thin film transistors and the recent achievements in the field.
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Affiliation(s)
- Irina Valitova
- Department of Chemical Engineering, École Polytechnique de Montréal, Montréal, Québec H3C 3A7, Canada
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163
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Sun Y, Padbury RP, Akyildiz HI, Goertz MP, Palmer JA, Jur JS. Influence of Subsurface Hybrid Material Growth on the Mechanical Properties of Atomic Layer Deposited Thin Films on Polymers. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/cvde.201207042] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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164
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Stolar M, Baumgartner T. Organic n-type materials for charge transport and charge storage applications. Phys Chem Chem Phys 2013; 15:9007-24. [PMID: 23674178 DOI: 10.1039/c3cp51379c] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Conjugated materials have attracted much attention toward applications in organic electronics in recent years. These organic species offer many advantages as potential replacement for conventional materials (i.e., silicon and metals) in terms of cheap fabrication and environmentally benign devices. While p-type (electron-donating or hole-conducting) materials have been extensively reviewed and researched, their counterpart n-type (electron-accepting or electron-conducting) materials have seen much less popularity despite the greater need for improvement. In addition to developing efficient charge transport materials, it is equally important to provide a means of charge storage, where energy can be used on an on-demand basis. This perspective is focused on discussing a selection of representative n-type materials and the efforts toward improving their charge-transport efficiencies. Additionally, this perspective will also highlight recent organic materials for battery components and the efforts that have been made to improve their environmental appeal.
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Affiliation(s)
- Monika Stolar
- Department of Chemistry and Centre for Advanced Solar Materials, University of Calgary, Calgary, AB, Canada
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165
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Photoconductive response in organic charge transfer interfaces with high quantum efficiency. Nat Commun 2013; 4:1842. [DOI: 10.1038/ncomms2890] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 04/17/2013] [Indexed: 11/08/2022] Open
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166
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Nakabayashi S, Shinozaki R, Senda Y, Yoshikawa HY. Hydrogen nanobubble at normal hydrogen electrode. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:184008. [PMID: 23598899 DOI: 10.1088/0953-8984/20/18/184008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Electrochemically formed hydrogen nanobubbles at a platinum rotating disk electrode (RDE) were detected by re-oxidation charge. The dissolution time course of the hydrogen nanobubbles was measured by AFM tapping topography under open-circuit conditions at stationary platinum and gold single-crystal electrodes. The bubble dissolution at platinum was much faster than that at gold because two types of diffusion, bulk and surface diffusion, proceeded at the platinum surface, whereas surface diffusion was prohibited at the gold electrode. These findings indicated that the electrochemical reaction of normal hydrogen electrode partly proceeded heterogeneously on the three-phase boundary around the hydrogen nanobubble.
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Affiliation(s)
- S Nakabayashi
- Department of Chemistry, Faculty of Science, Saitama University, Sakura-ku, Shimo-okubo, 225, Saitama 338-8570, Japan
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167
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Adkinson DK, Magri DC, Pitters JL, Griffiths K, Norton PR, Workentin MS. Photolysis and thermolysis of pyridyl carbonyl azide monolayers on single-crystal platinum. Photochem Photobiol 2013; 89:1020-8. [PMID: 23611516 DOI: 10.1111/php.12086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 04/17/2013] [Indexed: 11/29/2022]
Abstract
The photochemical and thermal reactivity of a number of acyl azide-substituted pyridine compounds, namely nicotinyl azide, isonicotinyl azide, picolinyl azide and dinicotinyl azide with investigated as saturated monolayers on a single-crystal Pt(111) surface in an ultrahigh vacuum chamber. Multilayers of the substrates exhibited a maximum rate of desorption at 270 K, above which, stable saturated monolayers formed as characterized by reflection-absorption infrared spectroscopy by observation of C=O and N3 bands at 1700 cm(-1), and 2100 and 1300 cm(-1) respectively. The monolayers were stable up to 400 K. Photolysis of the monolayer (or heating above 400 K) results in the formation of the respective isocyanate intermediate after loss of nitrogen as evidenced by the appearance of a new infrared band at 2260 cm(-1) with concomitant loss of the azide bands. The resulting isocyanate saturated monolayer is stable in absence of nucleophiles, but can be quenched with appropriate nucleophiles.
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Affiliation(s)
- Dana K Adkinson
- Department of Chemistry and the Centre for Advanced Materials and Biomaterials, The University of Western Ontario, London, ON, Canada
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168
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Borghetti P, Santo GD, Castellarin-Cudia C, Fanetti M, Sangaletti L, Magnano E, Bondino F, Goldoni A. Adsorption geometry, conformation, and electronic structure of 2H-octaethylporphyrin on Ag(111) and Fe metalation in ultra high vacuum. J Chem Phys 2013; 138:144702. [DOI: 10.1063/1.4798934] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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169
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Najafi E, Amini MM, Mohajerani E, Janghouri M, Razavi H, Khavasi H. Fabrication of an organic light-emitting diode (OLED) from a two-dimensional lead(II) coordination polymer. Inorganica Chim Acta 2013. [DOI: 10.1016/j.ica.2013.01.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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170
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Biswas S, Shalev O, Shtein M. Thin-film growth and patterning techniques for small molecular organic compounds used in optoelectronic device applications. Annu Rev Chem Biomol Eng 2013; 4:289-317. [PMID: 23540286 DOI: 10.1146/annurev-chembioeng-061312-103356] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Rapid advances in research and development in organic electronics have resulted in many exciting discoveries and applications, including organic light-emitting devices for information display and illumination, solar cells, photodetectors, chemosensors, and logic. Organic optoelectronic materials are broadly classified as polymeric or small molecular. For the latter category, solvent-free deposition techniques are generally preferred to form well-defined interfaces and improve device performance. This article reviews several deposition and patterning methods for small molecular thin films and devices, including organic molecular beam deposition, vacuum thermal evaporation, organic vapor phase deposition, and organic vapor jet printing, and compares them to several other methods that have been proposed recently. We hope this review provides a compact but informative summary of the state of the art in organic device processing and addresses the various techniques' governing physical principles.
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Affiliation(s)
- Shaurjo Biswas
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, USA.
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171
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Valentine AJS, Mazziotti DA. Theoretical Prediction of the Structures and Energies of Olympicene and its Isomers. J Phys Chem A 2013; 117:9746-52. [DOI: 10.1021/jp312384b] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Andrew J. S. Valentine
- Department
of Chemistry and
The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
| | - David A. Mazziotti
- Department
of Chemistry and
The James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
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172
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173
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174
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Zalake P, Thomas KG. Role of hydrogen bonding on the self-organization of phenyleneethynylenes on surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:2242-2249. [PMID: 23331130 DOI: 10.1021/la3048592] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A series of carboxylic acid substituted phenyleneethynylenes, having a rigid backbone of 2.7 ± 0.1 nm, were synthesized by following the Heck-Cassar-Sonagashira-Hagihara cross-coupling reaction. Hydrogen bonding, through the formation of cyclic dimers of carboxylic acid, is more preferred over catemeric structures in all the molecular systems under investigation. The formation of extended two-dimensional patterns on highly oriented pyrolitic graphite (HOPG) surface is dictated by the position as well as number of the carboxylic acid groups on the phenyleneethynylenes. Highly ordered extended arrangements, in the linear and stepwise fashion, were observed when the carboxylic acid groups are attached in the para and meta positions of phenyleneethynylenes. The vital role of the number of carboxylic acid on the organization of molecules is evident in the case of tetracarboxylic acid derivative wherein a Kagome-type structure was observed. Further, the coassembly of two types of phenyleneethynylenes was achieved on HOPG surface through acid base interaction.
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Affiliation(s)
- Pratap Zalake
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER-TVM), CET Campus, Thiruvananthapuram, India
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175
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Charged and metallic molecular monolayers through surface-induced aromatic stabilization. Nat Chem 2013; 5:187-94. [PMID: 23422560 DOI: 10.1038/nchem.1572] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 01/10/2013] [Indexed: 12/19/2022]
Abstract
Large π-conjugated molecules, when in contact with a metal surface, usually retain a finite electronic gap and, in this sense, stay semiconducting. In some cases, however, the metallic character of the underlying substrate is seen to extend onto the first molecular layer. Here, we develop a chemical rationale for this intriguing phenomenon. In many reported instances, we find that the conjugation length of the organic semiconductors increases significantly through the bonding of specific substituents to the metal surface and through the concomitant rehybridization of the entire backbone structure. The molecules at the interface are thus converted into different chemical species with a strongly reduced electronic gap. This mechanism of surface-induced aromatic stabilization helps molecules to overcome competing phenomena that tend to keep the metal Fermi level between their frontier orbitals. Our findings aid in the design of stable precursors for metallic molecular monolayers, and thus enable new routes for the chemical engineering of metal surfaces.
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176
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Egger D, Ruiz VG, Saidi WA, Bučko T, Tkatchenko A, Zojer E. Understanding Structure and Bonding of Multilayered Metal-Organic Nanostructures. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2013; 117:3055-3061. [PMID: 23447750 PMCID: PMC3579432 DOI: 10.1021/jp309943k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 12/13/2012] [Indexed: 05/07/2023]
Abstract
For organic and hybrid electronic devices, the physicochemical properties of the contained interfaces play a dominant role. To disentangle the various interactions occurring at such heterointerfaces, we here model a complex, yet prototypical, three-component system consisting of a Cu-phthalocyanine (CuPc) film on a 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) monolayer adsorbed on Ag(111). The two encountered interfaces are similar, as in both cases there would be no bonding without van der Waals interactions. Still, they are also distinctly different, as only at the Ag(111)-PTCDA interface do massive charge-rearrangements occur. Using recently developed theoretical tools, we show that it has become possible to provide atomistic insight into the physical and chemical processes in this comparatively complex nanostructure distinguishing between interactions involving local rearrangements of the charge density and long-range van der Waals attraction.
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Affiliation(s)
- David
A. Egger
- Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010
Graz, Austria
| | - Victor G. Ruiz
- Fritz-Haber-Institut
der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin,
Germany
| | - Wissam A. Saidi
- Department of Chemical
and Petroleum
Engineering, University of Pittsburgh,
1249 Benedum Hall, Pittsburgh, Pennsylvania 15261, United States
| | - Tomáš Bučko
- Department of Physical and Theoretical
Chemistry, Faculty of Natural Sciences, Comenius University, Mlynska Dolina, SK-84215 Bratislava, Slovakia
- Slovak Academy of Sciences, Institute
of Inorganic Chemistry, Dubravska cesta 9,
SK-84236 Bratislava, Slovakia
| | - Alexandre Tkatchenko
- Fritz-Haber-Institut
der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin,
Germany
| | - Egbert Zojer
- Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010
Graz, Austria
- E-mail:
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177
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Zhong S, Zhong JQ, Mao HY, Zhang JL, Lin JD, Chen W. The role of gap states in the energy level alignment at the organic-organic heterojunction interfaces. Phys Chem Chem Phys 2013; 14:14127-41. [PMID: 22903473 DOI: 10.1039/c2cp41107e] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The interface properties of organic-organic heterojunctions (OOHs), such as interface energy level alignment (ELA), interfacial charge transfer, interface nanostructuring, molecular orientation and so on, play an essential role in determining the device performance for some technologically important organic electronic devices, encompassing organic solar cells, bipolar organic field-effect-transistors, and organic light-emitting-diodes. The aim of this article is to provide a balanced assessment on the understanding of the ELA at the small-molecule based OOH interfaces with well-defined molecular orientation, with particular emphasis on the role of gap states in organic thin films. A generalized picture of gap states determined ELA at the OOH interfaces is provided and their implications in relevant organic electronic devices have been discussed.
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Affiliation(s)
- Shu Zhong
- Department of Chemistry, National University of Singapore, Singapore
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178
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Canepa M, Maidecchi G, Toccafondi C, Cavalleri O, Prato M, Chaudhari V, Esaulov VA. Spectroscopic ellipsometry of self assembled monolayers: interface effects. The case of phenyl selenide SAMs on gold. Phys Chem Chem Phys 2013; 15:11559-65. [DOI: 10.1039/c3cp51304a] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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179
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Hong SY, Yeh PC, Dadap JI, Osgood RM. Interfacial dipole formation and surface-electron confinement in low-coverage self-assembled thiol layers: thiophenol and p-fluorothiophenol on Cu(111). ACS NANO 2012. [PMID: 23181602 DOI: 10.1021/nn303715d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Model systems of organic self-assembled monolayers are important in achieving full atomic-scale understanding of molecular-electronic interfaces as well as the details of their charge transfer physics. Here we use two-photon photoemission to measure the evolving unoccupied and occupied interfacial electronic structure of two thiolate species, thiophenol and p-fluorothiophenol, adsorbed on Cu(111) as a function of molecular coverage. Our measurements focus on the role of adsorbates in shifting surface polarization and effecting surface electron confinement. As the coverage of each molecule increases, their photoemission-measured work functions exhibit nearly identical behavior up to 0.4-0.5 ML, at which point their behavior diverges; this behavior can be fit to an interfacial bond model for the surface dipole. In addition, our results show the emergence of an interfacial electronic state 0.1-0.2 eV below the Fermi level. This electronic state is attributed to quantum-mechanical-confinement shifting of the Cu(111) surface state by the molecular adsorbates.
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Affiliation(s)
- Sung-Young Hong
- Department of Chemistry, Columbia University, New York, New York 10027, USA
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180
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Dubacheva GV, Liang CK, Bassani DM. Functional monolayers from carbon nanostructures – fullerenes, carbon nanotubes, and graphene – as novel materials for solar energy conversion. Coord Chem Rev 2012. [DOI: 10.1016/j.ccr.2012.04.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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181
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Bodrenko IV, Sierka M, Fabiano E, Della Sala F. A periodic charge-dipole electrostatic model: parametrization for silver slabs. J Chem Phys 2012; 137:134702. [PMID: 23039605 DOI: 10.1063/1.4754719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present an extension of the charge-dipole model for the description of periodic systems. This periodic charge-dipole electrostatic model (PCDEM) allows one to describe the linear response of periodic structures in terms of charge- and dipole-type gaussian basis functions. The long-range electrostatic interaction is efficiently described by means of the continuous fast multipole method. As a first application, the PCDEM method is applied to describe the polarizability of silver slabs. We find that for a correct description of the polarizability of the slabs both charges and dipoles are required. However a continuum set of parametrizations, i.e., different values of the width of charge- and dipole-type gaussians, leads to an equivalent and accurate description of the slabs polarizability but a completely unphysical description of induced charge-density inside the slab. We introduced the integral squared density measure which allows one to obtain a unique parametrization which accurately describes both the polarizability and the induced density profile inside the slab. Finally the limits of the electrostatic approximations are also pointed out.
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Affiliation(s)
- I V Bodrenko
- National Nanotechnology Laboratory (NNL), Istituto Nanoscienze-CNR, Via per Arnesano 16, 73100 Lecce, Italy
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182
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Chwee TS, Sullivan MB. Adsorption studies of C6H6 on Cu (111), Ag (111), and Au (111) within dispersion corrected density functional theory. J Chem Phys 2012; 137:134703. [DOI: 10.1063/1.4755993] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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183
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Domanski AL, Sengupta E, Bley K, Untch MB, Weber SAL, Landfester K, Weiss CK, Butt HJ, Berger R. Kelvin probe force microscopy in nonpolar liquids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:13892-9. [PMID: 22946889 DOI: 10.1021/la302451h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Work function changes of Au were measured by Kelvin probe force microscopy (KPFM) in the nonpolar liquid decane. As a proof of principle for the measurement in liquids, we investigated the work function change of an Au substrate upon hexadecanethiol chemisorption. To relate the measured contact potential difference (CPD) during the chemisorption of alkanethiols to a change of the work function, the influence of physisorbed decane must be taken into account. It is crucial that either the work function of the scanning probe microscope (SPM) tip or the sample surface remains constant throughout the reaction, since both contribute to the CPD. We describe two routes for determining the work function shift of Au coated with a monolayer of alkanethiols: In the first route, the SPM tips were taken as reference surfaces (constant tip work function). For this approach, we used Au(111) surfaces and kept the SPM tip ex situ during the adsorption process. In the second route, structured surfaces with reactive and inert parts were studied by KPFM (constant reference work function). For this route, we prepared nanometer sized Au structures by nanosphere lithography on SiO(x) substrates. Now, the SiO(x) served as the inert reference surface. The shifts in the work function after exposure to the hexadecanethiol (HDT) solution were determined to be ΔΦ(Au+HDT,decane-Au,air) = -1.33 eV ± 0.07 eV (route I) and ΔΦ(Au+HDT,decane-Au,air) = -1.46 eV ± 0.04 eV (route II). Both values are in excellent agreement with the work function shifts determined by ultraviolet photoemission spectroscopy (UPS) reported in literature. The presented procedures of measuring work function changes in decane open new ways to study local reactions at solid-liquid interfaces.
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184
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Carreras J, Patil M, Thiel W, Alcarazo M. Exploiting the π-Acceptor Properties of Carbene-Stabilized Phosphorus Centered Trications [L3P] 3+: Applications in Pt(II) Catalysis. J Am Chem Soc 2012; 134:16753-8. [DOI: 10.1021/ja306947m] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Javier Carreras
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, D-45470 Mülheim an der Ruhr, Germany
| | - Mahendra Patil
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, D-45470 Mülheim an der Ruhr, Germany
| | - Walter Thiel
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, D-45470 Mülheim an der Ruhr, Germany
| | - Manuel Alcarazo
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, D-45470 Mülheim an der Ruhr, Germany
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185
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Gutiérrez Lezama I, Nakano M, Minder NA, Chen Z, Di Girolamo FV, Facchetti A, Morpurgo AF. Single-crystal organic charge-transfer interfaces probed using Schottky-gated heterostructures. NATURE MATERIALS 2012; 11:788-94. [PMID: 22820687 DOI: 10.1038/nmat3383] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 06/19/2012] [Indexed: 05/24/2023]
Abstract
Organic semiconductors based on small conjugated molecules generally behave as insulators when undoped, but the heterointerfaces of two such materials can show electrical conductivity as large as in a metal. Although charge transfer is commonly invoked to explain the phenomenon, the details of the process and the nature of the interfacial charge carriers remain largely unexplored. Here we use Schottky-gated heterostructures to probe the conducting layer at the interface between rubrene and PDIF-CN(2) single crystals. Gate-modulated conductivity measurements demonstrate that interfacial transport is due to electrons, whose mobility exhibits band-like behaviour from room temperature to ~150 K, and remains as high as ~1 cm(2) V(-1) s(-1) at 30 K for the best devices. The electron density decreases linearly with decreasing temperature, an observation that can be explained quantitatively on the basis of the heterostructure band diagram. These results elucidate the electronic structure of rubrene/PDIF-CN(2) interfaces and show the potential of Schottky-gated organic heterostructures for the investigation of transport in molecular semiconductors.
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186
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Yimer YY, Dhinojwala A, Tsige M. Interfacial properties of free-standing poly(3-hexylthiophene) films. J Chem Phys 2012; 137:044703. [DOI: 10.1063/1.4736571] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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187
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Matz DL, Schalnat MC, Pemberton JE. Reaction of Thin Films of Solid-State Benzene and Pyridine with Calcium. J Am Chem Soc 2012; 134:12989-97. [DOI: 10.1021/ja3016186] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dallas L. Matz
- Department of Chemistry
and Biochemistry, University of Arizona, 1306 East University Boulevard,
Tucson, Arizona 85721, United States
| | - Matthew C. Schalnat
- Department of Chemistry
and Biochemistry, University of Arizona, 1306 East University Boulevard,
Tucson, Arizona 85721, United States
| | - Jeanne E. Pemberton
- Department of Chemistry
and Biochemistry, University of Arizona, 1306 East University Boulevard,
Tucson, Arizona 85721, United States
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188
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Lacher S, Obata N, Luo SC, Matsuo Y, Zhu B, Yu HH, Nakamura E. Electropolymerized conjugated polyelectrolytes with tunable work function and hydrophobicity as an anode buffer in organic optoelectronics. ACS APPLIED MATERIALS & INTERFACES 2012; 4:3396-3404. [PMID: 22738167 DOI: 10.1021/am300366d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A new class of conductive polyelectrolyte films with tunable work function and hydrophobicity has been developed for the anode buffer layer in organic electronic devices. The work function of these films featuring a copolymer of ethylenedioxythiophene (EDOT), and its functionalized analogues were found to be easily tunable over a range of almost 1 eV and reach values as high as those of PEDOT:PSS. The new buffer material does not need the addition of any insulating or acidic material that might limit the film conductivity or device lifetime. Organic photovoltaic devices built with these films showed improved open-circuit voltage over those of the known PSS-free conductive EDOT-based polymers with values as high as that obtained for PEDOT:PSS. Furthermore, the surface hydrophobicity of these new copolymer films was found to be sensitive to the chemical groups attached to the polymer backbone, offering an attractive method for surface energy tuning.
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Affiliation(s)
- Sebastian Lacher
- Department of Chemistry, The University of Tokyo , Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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189
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Martínez JI, Abad E, González C, Flores F, Ortega J. Improvement of scanning tunneling microscopy resolution with H-sensitized tips. PHYSICAL REVIEW LETTERS 2012; 108:246102. [PMID: 23004294 DOI: 10.1103/physrevlett.108.246102] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Indexed: 05/12/2023]
Abstract
Recent scanning tunneling hydrogen microscopy (STHM) experiments on PTCDA (perylene-3,4,9,10-tetracarboxylic-3,4,9,10-dianhydride)/Au(111) have shown unprecedented intramolecular and intermolecular spatial resolution. The origin of this resolution is studied using an accurate STHM theoretical simulation technique that includes a detailed description of the electronic structure of both the tip and sample. Our results show that H2 molecules are dissociated on the Au tip; the adsorbed H atoms change the density of states at the Fermi level (E(F)) of the tip, increasing its p-orbital character and reducing the s-orbital contribution. Also, due to the interaction with the H-decorated tip, E(F) is shifted to the middle of the PTCDA lowest unoccupied molecular orbital peak, increasing dramatically the density of states of the sample at E(F). These effects give rise to the enhanced STHM resolution.
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Affiliation(s)
- J I Martínez
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, ES-28049 Madrid, Spain.
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190
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Fazaeli Y, Amini MM, Najafi E, Mohajerani E, Janghouri M, Jalilian A, Ng SW. Synthesis and Characterization of 8-hydroxyquinoline Complexes of Tin(IV) and Their Application in Organic Light Emitting Diode. J Fluoresc 2012; 22:1263-70. [DOI: 10.1007/s10895-012-1068-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 05/28/2012] [Indexed: 10/28/2022]
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191
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Lin HC, Polaske NW, Oquendo LE, Gliboff M, Knesting KM, Nordlund D, Ginger DS, Ratcliff EL, Beam BM, Armstrong NR, McGrath DV, Saavedra SS. Electron-Transfer Processes in Zinc Phthalocyanine-Phosphonic Acid Monolayers on ITO: Characterization of Orientation and Charge-Transfer Kinetics by Waveguide Spectroelectrochemistry. J Phys Chem Lett 2012; 3:1154-1158. [PMID: 26288050 DOI: 10.1021/jz3002426] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Using a monolayer of zinc phthalocyanine (ZnPcPA) tethered to indium tin oxide (ITO) as a model for the donor/transparent conducting oxide (TCO) interface in organic photovoltaics (OPVs), we demonstrate the relationship between molecular orientation and charge-transfer rates using spectroscopic, electrochemical, and spectroelectrochemical methods. Both monomeric and aggregated forms of the phthalocyanine (Pc) are observed in ZnPcPA monolayers. Potential-modulated attenuated total reflectance (PM-ATR) measurements show that the monomeric subpopulation undergoes oxidation/reduction with ks,app = 2 × 10(2) s(-1), independent of Pc orientation. For the aggregated ZnPcPA, faster orientation-dependent charge-transfer rates are observed. For in-plane-oriented Pc aggregates, ks,app = 2 × 10(3) s(-1), whereas for upright Pc aggregates, ks,app = 7 × 10(2) s(-1). The rates for the aggregates are comparable to those required for redox-active interlayer films at the hole-collection contact in organic solar cells.
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Affiliation(s)
- Hsiao-Chu Lin
- †Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Nathan W Polaske
- †Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Luis E Oquendo
- †Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | | | | | - Dennis Nordlund
- #Stanford Synchrotron Radiation Laboratory, 2575 Sand Hill Road MS69, Menlo Park, California 94025, United States
| | | | - Erin L Ratcliff
- †Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Brooke M Beam
- †Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Neal R Armstrong
- †Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - Dominic V McGrath
- †Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
| | - S Scott Saavedra
- †Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, United States
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192
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Lee BR, Kim JW, Kang D, Lee DW, Ko SJ, Lee HJ, Lee CL, Kim JY, Shin HS, Song MH. Highly efficient polymer light-emitting diodes using graphene oxide as a hole transport layer. ACS NANO 2012; 6:2984-2991. [PMID: 22390380 DOI: 10.1021/nn300280q] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We present an investigation of polymer light-emitting diodes (PLEDs) with a solution-processable graphene oxide (GO) interlayer. The GO layer with a wide band gap blocks electron transport from an emissive polymer to an ITO anode while reducing the exciton quenching between the GO and the active layer in place of poly(styrenesulfonate)-doped poly(3,4-ethylenedioxythiophene) (PEDOT:PSS). This GO interlayer maximizes hole-electron recombinations within the emissive layer, finally enhancing device performance and efficiency levels in PLEDs. It was found that the thickness of the GO layer is an important factor in device performance. PLEDs with a 4.3 nm thick GO interlayer are superior to both those with PEDOT:PSS layers as well as those with rGO, showing maximum luminance of 39 000 Cd/m(2), maximum luminous efficiencies of 19.1 Cd/A (at 6.8 V), and maximum power efficiency as high as 11.0 lm/W (at 4.4 V). This indicates that PLEDs with a GO layer show a 220% increase in their luminous efficiency and 280% increase in their power conversion efficiency compared to PLEDs with PEDOT:PSS.
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Affiliation(s)
- Bo Ram Lee
- School of Mechanical and Advanced Materials Engineering, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 689-805, Republic of Korea
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193
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Mahns B, Roth F, Grobosch M, Lindner S, Knupfer M, Saragi TPI, Reichert T, Salbeck J, Hahn T. Electronic properties of spiro compounds for organic electronics. J Chem Phys 2012; 136:124702. [DOI: 10.1063/1.3698280] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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194
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Surface Intiated Atom Transfer Radical Polymerizations from Indium Tin Oxide Electrodes: Electrochemistry of Polymer Brushes. ACTA ACUST UNITED AC 2012. [DOI: 10.1021/bk-2012-1101.ch013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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195
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Lou Y, Wang Z, Naka S, Okada H. Charge transport characteristics in P3HT:PCBM organic blends under illumination: Influence of metal work functions. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2012.01.057] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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196
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Anger F, Ossó JO, Heinemeyer U, Broch K, Scholz R, Gerlach A, Schreiber F. Photoluminescence spectroscopy of pure pentacene, perfluoropentacene, and mixed thin films. J Chem Phys 2012; 136:054701. [DOI: 10.1063/1.3677839] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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197
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Hinderhofer A, Schreiber F. Organic-Organic Heterostructures: Concepts and Applications. Chemphyschem 2012; 13:628-43. [DOI: 10.1002/cphc.201100737] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Indexed: 11/06/2022]
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198
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Electrically driven photon antibunching from a single molecule at room temperature. Nat Commun 2012; 3:628. [PMID: 22252552 DOI: 10.1038/ncomms1637] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 12/07/2011] [Indexed: 11/08/2022] Open
Abstract
Single-photon emitters have been considered for applications in quantum information processing, quantum cryptography and metrology. For the sake of integration and to provide an electron photon interface, it is of great interest to stimulate single-photon emission by electrical excitation as demonstrated for quantum dots. Because of low exciton binding energies, it has so far not been possible to detect sub-Poissonian photon statistics of electrically driven quantum dots at room temperature. However, organic molecules possess exciton binding energies on the order of 1eV, thereby facilitating the development of an electrically driven single-photon source at room temperature in a solid-state matrix. Here we demonstrate electroluminescence of single, electrically driven molecules at room temperature. By careful choice of the molecular emitter, as well as fabrication of a specially designed organic light-emitting diode structure, we were able to achieve stable single-molecule emission and detect sub-Poissonian photon statistics.
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199
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Park JS, Lee JM, Hwang SK, Lee SH, Lee HJ, Lee BR, Park HI, Kim JS, Yoo S, Song MH, Kim SO. A ZnO/N-doped carbon nanotube nanocomposite charge transport layer for high performance optoelectronics. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm30710c] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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200
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Interface Electronic Structure of Zinc-Phthalocyanine on the Silver Thin-Film Quantum-Well. E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY 2012. [DOI: 10.1380/ejssnt.2012.149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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