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Seo D, Seong S, Kim H, Oh HS, Lee JH, Kim H, Kim YO, Maeda S, Chikami S, Hayashi T, Noh J. Molecular Self-Assembly and Adsorption Structure of 2,2'-Dipyrimidyl Disulfides on Au(111) Surfaces. Molecules 2024; 29:846. [PMID: 38398598 PMCID: PMC10892263 DOI: 10.3390/molecules29040846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/08/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024] Open
Abstract
The effects of solution concentration and pH on the formation and surface structure of 2-pyrimidinethiolate (2PymS) self-assembled monolayers (SAMs) on Au(111) via the adsorption of 2,2'-dipyrimidyl disulfide (DPymDS) were examined using scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). STM observations revealed that the formation and structural order of 2PymS SAMs were markedly influenced by the solution concentration and pH. 2PymS SAMs formed in a 0.01 mM ethanol solution were mainly composed of a more uniform and ordered phase compared with those formed in 0.001 mM or 1 mM solutions. SAMs formed in a 0.01 mM solution at pH 2 were composed of a fully disordered phase with many irregular and bright aggregates, whereas SAMs formed at pH 7 had small ordered domains and many bright islands. As the solution pH increased from pH 7 to pH 12, the surface morphology of 2PymS SAMs remarkably changed from small ordered domains to large ordered domains, which can be described as a (4√2 × 3)R51° packing structure. XPS measurements clearly showed that the adsorption of DPymDS on Au(111) resulted in the formation of 2PymS (thiolate) SAMs via the cleavage of the disulfide (S-S) bond in DPymDS, and most N atoms in the pyrimidine rings existed in the deprotonated form. The results herein will provide a new insight into the molecular self-assembly behaviors and adsorption structures of DPymDS molecules on Au(111) depending on solution concentration and pH.
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Affiliation(s)
- Dongjin Seo
- Department of Chemistry, Hanyang University, Seoul 04763, Republic of Korea; (D.S.); (S.S.); (H.K.); (H.S.O.); (J.H.L.); (H.K.); (Y.O.K.)
| | - Sicheon Seong
- Department of Chemistry, Hanyang University, Seoul 04763, Republic of Korea; (D.S.); (S.S.); (H.K.); (H.S.O.); (J.H.L.); (H.K.); (Y.O.K.)
| | - Haeri Kim
- Department of Chemistry, Hanyang University, Seoul 04763, Republic of Korea; (D.S.); (S.S.); (H.K.); (H.S.O.); (J.H.L.); (H.K.); (Y.O.K.)
| | - Hyun Su Oh
- Department of Chemistry, Hanyang University, Seoul 04763, Republic of Korea; (D.S.); (S.S.); (H.K.); (H.S.O.); (J.H.L.); (H.K.); (Y.O.K.)
| | - Jun Hyeong Lee
- Department of Chemistry, Hanyang University, Seoul 04763, Republic of Korea; (D.S.); (S.S.); (H.K.); (H.S.O.); (J.H.L.); (H.K.); (Y.O.K.)
| | - Hongki Kim
- Department of Chemistry, Hanyang University, Seoul 04763, Republic of Korea; (D.S.); (S.S.); (H.K.); (H.S.O.); (J.H.L.); (H.K.); (Y.O.K.)
| | - Yeon O Kim
- Department of Chemistry, Hanyang University, Seoul 04763, Republic of Korea; (D.S.); (S.S.); (H.K.); (H.S.O.); (J.H.L.); (H.K.); (Y.O.K.)
| | - Shoichi Maeda
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Yokohama 226-8503, Japan; (S.M.); (S.C.)
| | - Shunta Chikami
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Yokohama 226-8503, Japan; (S.M.); (S.C.)
| | - Tomohiro Hayashi
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Yokohama 226-8503, Japan; (S.M.); (S.C.)
| | - Jaegeun Noh
- Department of Chemistry, Hanyang University, Seoul 04763, Republic of Korea; (D.S.); (S.S.); (H.K.); (H.S.O.); (J.H.L.); (H.K.); (Y.O.K.)
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Yokohama 226-8503, Japan; (S.M.); (S.C.)
- Research Institute for Convergence of Basic Science, Hanyang University, Seoul 04763, Republic of Korea
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Azzam W, Subaihi A, Rohwerder M, Zharnikov M, Bashir A. Polymorphism and Building-Block-Resolved STM Imaging of Self-Assembled Monolayers of 4-Fluorobenzenemethanethiol on Au(111). Chemphyschem 2022; 23:e202200347. [PMID: 35856831 DOI: 10.1002/cphc.202200347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/17/2022] [Indexed: 11/06/2022]
Abstract
Self-assembled monolayers (SAMs) of 4-fluorobenzenemethanethiol (p-FBMT) on Au(111), prepared by immersion procedure (1 mM ethanolic solution; 60 °C; 18 h), were characterized by scanning tunneling microscopy (STM). The data suggest the formation of highly ordered monolayer with a commensurate structure, described by the 2 3 × 13 R 13 ∘ unit cell. The STM appearance of this cell occurs, however, in two different forms, with either well-localized individual spots or splitting of these spots in two components. These components are assigned to the tunneling through the entire molecule or sulfur docking group only. The respective spots correspond then to the terminal fluorine atom and sulfur docking group, manifesting, thus, building-block-resolving STM imaging. The accessibility of the docking group for direct tunneling is most likely related to a specific molecular organization for one of the two possible internal structures of the unit cell. The above results represent a showcase for potential of STM for imaging of upright-arranged and densely packed molecular assemblies, such as SAMs.
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Affiliation(s)
- Waleed Azzam
- Department of Chemistry, Tafila Technical University, P.O. Box 179, Tafila, 66110, Jordan.,Department of Chemistry, University College in Al-Qunfudah, Umm Al-Qura University, 1109, Makkah, Al-Mukarramah, Saudi Arabia
| | - Abdu Subaihi
- Department of Chemistry, University College in Al-Qunfudah, Umm Al-Qura University, 1109, Makkah, Al-Mukarramah, Saudi Arabia
| | - Michael Rohwerder
- Max-Planck-Institut fuer Eisenforschung GmbH, Max-Planck-Str. 1, 40237, Düsseldorf, Germany
| | - Michael Zharnikov
- Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany
| | - Asif Bashir
- Thyssenkrupp Bilstein GmbH, Herner Str. 299, 44809, Bochum, Germany
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Borchert JW, Zschieschang U, Letzkus F, Giorgio M, Weitz RT, Caironi M, Burghartz JN, Ludwigs S, Klauk H. Flexible low-voltage high-frequency organic thin-film transistors. SCIENCE ADVANCES 2020; 6:eaaz5156. [PMID: 32671209 PMCID: PMC7314562 DOI: 10.1126/sciadv.aaz5156] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 03/10/2020] [Indexed: 05/20/2023]
Abstract
The primary driver for the development of organic thin-film transistors (TFTs) over the past few decades has been the prospect of electronics applications on unconventional substrates requiring low-temperature processing. A key requirement for many such applications is high-frequency switching or amplification at the low operating voltages provided by lithium-ion batteries (~3 V). To date, however, most organic-TFT technologies show limited dynamic performance unless high operating voltages are applied to mitigate high contact resistances and large parasitic capacitances. Here, we present flexible low-voltage organic TFTs with record static and dynamic performance, including contact resistance as small as 10 Ω·cm, on/off current ratios as large as 1010, subthreshold swing as small as 59 mV/decade, signal delays below 80 ns in inverters and ring oscillators, and transit frequencies as high as 21 MHz, all while using an inverted coplanar TFT structure that can be readily adapted to industry-standard lithographic techniques.
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Affiliation(s)
- James W. Borchert
- Max Planck Institute for Solid State Research, Stuttgart, Germany
- Institute of Polymer Chemistry, Universität Stuttgart, Stuttgart, Germany
| | - Ute Zschieschang
- Max Planck Institute for Solid State Research, Stuttgart, Germany
| | - Florian Letzkus
- Institut für Mikroelektronik Stuttgart (IMS CHIPS), Stuttgart, Germany
| | - Michele Giorgio
- Center for Nano Science and Technology@PoliMi Milano, Istituto Italiano di Tecnologia, Milan, Italy
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
| | - R. Thomas Weitz
- Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Germany
- Center for Nanoscience (CeNS), Munich, Germany
- Munich Center for Quantum Science and Technology (MCQST), Munich, Germany
| | - Mario Caironi
- Center for Nano Science and Technology@PoliMi Milano, Istituto Italiano di Tecnologia, Milan, Italy
| | | | - Sabine Ludwigs
- Institute of Polymer Chemistry, Universität Stuttgart, Stuttgart, Germany
| | - Hagen Klauk
- Max Planck Institute for Solid State Research, Stuttgart, Germany
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Azzam W, Al-Rashdi A, Subaihi A, Rohwerder M, Zharnikov M, Bashir A. Annealing effect for self-assembled monolayers formed from terphenylethanethiol on Au(111). Phys Chem Chem Phys 2020; 22:13580-13591. [DOI: 10.1039/d0cp02374d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Formation of several different structural phases and desorption took place from a standing-up phase at an annealing temperature of 473 K.
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Affiliation(s)
- Waleed Azzam
- Department of Chemistry
- Tafila Technical University
- Tafila 66110
- Jordan
- Department of Chemistry
| | - Awad Al-Rashdi
- Department of Chemistry
- University College in Al-Qunfudah
- Umm Al-Qura University
- 1109 Makkah Al-Mukarramah
- Saudi Arabia
| | - Abdu Subaihi
- Department of Chemistry
- University College in Al-Qunfudah
- Umm Al-Qura University
- 1109 Makkah Al-Mukarramah
- Saudi Arabia
| | | | - Michael Zharnikov
- Angewandte Physikalische Chemie
- Universität Heidelberg
- 69120 Heidelberg
- Germany
| | - Asif Bashir
- Thyssenkrupp Bilstein GmbH
- 44809 Bochum
- Germany
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Bashir A, Sauter E, Al-Refaie N, Rohwerder M, Zharnikov M, Azzam W. Side-Group-Induced Polymorphism in Self-Assembled Monolayers: 3,5-Bis(trifluoromethyl)benzenethiolate Films on Au(111). Chemphyschem 2017; 18:702-714. [DOI: 10.1002/cphc.201700030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Asif Bashir
- Thyssenkrupp Bilstein GmbH; Niederkell 25 54429 Mandern Germany
- Max-Planck-Institut für Eisenforschung GmbH; Max-Planck-Str. 1 40237 Düsseldorf Germany
| | - Eric Sauter
- Applied Physical Chemistry; Heidelberg University; Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Najd Al-Refaie
- Department of Chemistry; University College in Al-Qunfudah, Umm Al-Qura University; 1109 Makkah Al-Mukarramah Saudi Arabia
| | - Michael Rohwerder
- Max-Planck-Institut für Eisenforschung GmbH; Max-Planck-Str. 1 40237 Düsseldorf Germany
| | - Michael Zharnikov
- Applied Physical Chemistry; Heidelberg University; Im Neuenheimer Feld 253 69120 Heidelberg Germany
| | - Waleed Azzam
- Department of Chemistry; University College in Al-Qunfudah, Umm Al-Qura University; 1109 Makkah Al-Mukarramah Saudi Arabia
- Department of Chemistry; Tafila Technical University; P.O. Box 179 Tafila 66110 Jordan
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6
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Ghalgaoui A, Doudin N, Sterrer M. Nanostructuring of Au(111) during the Adsorption of an Aromatic Isocyanide from Solution. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:91-99. [PMID: 27996271 DOI: 10.1021/acs.langmuir.6b03759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present a combined vibrational and morphological characterization of the self-assembly of 1,4-phenylene-diisocyanide (PDI) on Au(111) from methanol solution. Vibrational sum frequency generation (vSFG) and scanning tunneling microscopy (STM) have been applied to determine the adsorption geometry of the PDI-Au adatom complexes as well as the morphological transformations of the Au(111) substrate upon SAM formation from solutions with PDI concentrations in the μM to mM range. At low concentration/coverage, PDI adsorbs in flat adsorption geometry, with both isocyanide groups attached to Au adatoms on the Au(111) surface. Transformation to a standing-up phase is observed with increasing concentration/coverage. In contrast to findings for PDI adsorbed in ultrahigh vacuum, PDI does not form a long-range-ordered monolayer phase when adsorbed from solution. In addition, the Au(111) surface is subjected to structural modifications. Au vacancy islands and ad-islands, which are typical substrate defects formed during the self-assembly of aromatic thiols on Au(111), are also created during PDI adsorption from solution. At low PDI concentration, the Au vacancy islands and ad-islands are found at specific sites mediated by the herringbone reconstruction of the Au(111) surface, giving rise to long-range-ordered structures. These structures do not form during UHV adsorption of PDI on Au(111) nor has a similar ordering effect been observed for any related thiol-SAM system investigated so far.
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Affiliation(s)
- Ahmed Ghalgaoui
- Institute of Physics, University of Graz , Universitätsplatz 5, A-8010 Graz, Austria
- Department of Chemical Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, D-14195 Berlin, Germany
| | - Nassar Doudin
- Institute of Physics, University of Graz , Universitätsplatz 5, A-8010 Graz, Austria
| | - Martin Sterrer
- Institute of Physics, University of Graz , Universitätsplatz 5, A-8010 Graz, Austria
- Department of Chemical Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, D-14195 Berlin, Germany
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7
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Mezour MA, Choueiri RM, Lukoyanova O, Lennox RB, Perepichka DF. Hydrogen bonding vs. molecule-surface interactions in 2D self-assembly of [C60]fullerenecarboxylic acids. NANOSCALE 2016; 8:16955-16962. [PMID: 27714083 DOI: 10.1039/c6nr04115a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The adsorption of C60-malonic derivatives C61(CO2H)2 and C66(CO2H)12 on Au(111) and a pentafluorobenzenethiol-modified Au substrate (PFBT@Au) has been investigated using scanning tunneling microscopy (STM) at a liquid-solid interface. Monofunctionalized C61(CO2H)2 forms a hexagonal close-packed overlayer on Au(111) and individual aligned dimers on PFBT@Au(111). The difference is attributed to the nature of the substrateC61(CO2H)2 interaction (isotropic π-Au bonding vs. anisotropic PFBTCOOH interactions). Surprisingly, in both cases, the directionality of the COOHCOOH motif is compromised in favor of synergistic van der Waals/H bonding interactions. Such van der Waals contacts are geometrically unfeasible in hexafunctionalized C66(CO2H)12 and its assembly on Au(111) leads to a 2D molecular network controlled exclusively by H bonding. For both molecules, the "free" CO2H groups on the monolayer surface can engage in out-of-plane H bonding interaction resulting in the epitaxial growth of subsequent molecular layers.
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Affiliation(s)
- Mohamed A Mezour
- Department of Chemistry and Centre for Self-Assembled Chemical Structures, McGill University, 801 Sherbrooke St. West, Montreal, QC H3A 0B8, Canada.
| | - Rachelle M Choueiri
- Department of Chemistry and Centre for Self-Assembled Chemical Structures, McGill University, 801 Sherbrooke St. West, Montreal, QC H3A 0B8, Canada.
| | - Olena Lukoyanova
- Department of Chemistry and Centre for Self-Assembled Chemical Structures, McGill University, 801 Sherbrooke St. West, Montreal, QC H3A 0B8, Canada.
| | - R Bruce Lennox
- Department of Chemistry and Centre for Self-Assembled Chemical Structures, McGill University, 801 Sherbrooke St. West, Montreal, QC H3A 0B8, Canada.
| | - Dmitrii F Perepichka
- Department of Chemistry and Centre for Self-Assembled Chemical Structures, McGill University, 801 Sherbrooke St. West, Montreal, QC H3A 0B8, Canada.
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8
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Wang X, Zhong JH, Zhang M, Liu Z, Wu DY, Ren B. Revealing Intermolecular Interaction and Surface Restructuring of an Aromatic Thiol Assembling on Au(111) by Tip-Enhanced Raman Spectroscopy. Anal Chem 2015; 88:915-21. [DOI: 10.1021/acs.analchem.5b03588] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Xiang Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Jin-Hui Zhong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Meng Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Zheng Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - De-Yin Wu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Bin Ren
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), The MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
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Shrestha BR, Bashir A, Ankah GN, Valtiner M, Renner FU. Localized dealloying corrosion mediated by self-assembled monolayers used as an inhibitor system. Faraday Discuss 2015; 180:191-204. [DOI: 10.1039/c4fd00256c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The structure and chemistry of thiol or selenol self-assembled organic monolayers have been frequently addressed due to the unique opportunities in functionalization of materials. Such organic films can also act as effective inhibition layers to mitigate oxidation or corrosion. Cu–Au alloy substrates covered by self-assembled monolayers show a different dealloying mechanism compared to bare surfaces. The organic surface layer inhibits dealloying of noble metal alloys by a suppression of surface diffusion at lower potentials but at higher applied potentials dealloying proceeds in localized regions due to passivity breakdown. We present an in situ atomic force microscopy study of a patterned thiol layer applied on Cu–Au alloy surfaces and further explore approaches to change the local composition of the surface layers by exchange of molecules. The pattern for the in situ experiment has been applied by micro-contact printing. This allows the study of corrosion protection with its dependence on different molecule densities at different sites. Low-density thiol areas surrounding the high-density patterns are completely protected and initiation of dealloying proceeds only along the areas with the lowest inhibitor concentration. Dealloying patterns are highly influenced and controlled by molecular thiol to selenol exchange and are also affected by introducing structural defects such as scratches or polishing defects.
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Affiliation(s)
- B. R. Shrestha
- Max-Planck-Institut für Eisenforschung GmbH
- D-40237 Düsseldorf
- Germany
| | - A. Bashir
- Max-Planck-Institut für Eisenforschung GmbH
- D-40237 Düsseldorf
- Germany
| | - G. N. Ankah
- Max-Planck-Institut für Eisenforschung GmbH
- D-40237 Düsseldorf
- Germany
| | - M. Valtiner
- Max-Planck-Institut für Eisenforschung GmbH
- D-40237 Düsseldorf
- Germany
| | - F. U. Renner
- Max-Planck-Institut für Eisenforschung GmbH
- D-40237 Düsseldorf
- Germany
- Institute of Materials Research (IMO)
- Hasselt University
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Kim CH, Hlaing H, Carta F, Bonnassieux Y, Horowitz G, Kymissis I. Templating and charge injection from copper electrodes into solution-processed organic field-effect transistors. ACS APPLIED MATERIALS & INTERFACES 2013; 5:3716-3721. [PMID: 23611406 DOI: 10.1021/am400325k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Solution-processed organic field-effect transistors (OFETs) using chemically modified copper electrodes are reported. The purpose of this study is to shed light on the use of inexpensive copper electrodes in bottom-contact OFETs, which is consistent with the major goal of organic electronics: the realization of low-cost electronics. 6,13-Bis(triisopropylsilylethynyl)pentacene was used for solution-processed hole-transporting molecular films and pentafluorobenzenethiol was used to form self-assembled monolayers (SAMs) on the contact metals. We conducted a comparative study on copper and gold contacts and realized that, under the same performance improvement schemes, via SAM treatment and controlled crystal growth, the copper electrode device experienced a more significant enhancement than the gold electrode device. We attribute the beneficial effects of SAMs to the improved charge injection and transport properties, which are critical double effects from the fluorinated aromatic SAM structure. Grazing-incidence wide-angle X-ray scattering (GIWAXS) measurements showed that templating property of SAMs promotes the crystallization of TIPS-pentacene films at the metal/organic interface. The presented result indicates that copper can be regarded as a promising candidate for reducing the use of gold in organic-based circuits and systems, where the cost-effective production is an important issue.
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Affiliation(s)
- Chang Hyun Kim
- LPICM, Ecole Polytechnique, CNRS, 91128 Palaiseau, France.
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Cometto FP, Patrito EM, Paredes Olivera P, Zampieri G, Ascolani H. Electrochemical, high-resolution photoemission spectroscopy and vdW-DFT study of the thermal stability of benzenethiol and benzeneselenol monolayers on Au(111). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:13624-13635. [PMID: 22946792 DOI: 10.1021/la3024937] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The preparation and thermal stability of benzenethiol and benzeneselenol self-assembled monolayers (SAMs) grown on Au(111) have been investigated by electrochemical experiments and high-resolution photoemission spectroscopy. Both techniques confirm the formation of monolayers with high packing densities (θ = 0.27-0.29 ML) and good degrees of order in both cases. Despite many similarities between the two SAMs, the thermal desorption is distinctly different: whereas the benzenethiol SAM desorbs in a single steplike process, the desorption of the benzeneselenol SAM occurs with a much lower activation energy and involves the cleavage of some Se-C bonds and a change in molecular configuration from standing up to lying down. This behavior is explained by considering the different nature of the bonding of the headgroup with the metal surface and with the phenyl ring. Density functional theory calculations show that the breakage of the Se-C bond has a lower activation energy barrier than the breakage of the S-C bond.
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Affiliation(s)
- F P Cometto
- Departamento de Fisico Química, Instituto de Fisicoquímica de Córdoba, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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