1
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Chazarin U, Lezoualc'h M, Karn A, Chou JP, Pai WW, Chacon C, Girard Y, Repain V, Bellec A, Rousset S, González C, Smogunov A, Lagoute J, Dappe YJ. Spatially Extended Charge Density Wave Switching by Nanoscale Local Manipulation in a VTe 2 Monolayer. Nano Lett 2024; 24:3470-3475. [PMID: 38451177 DOI: 10.1021/acs.nanolett.4c00265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Monolayer transition metal dichalcogenide VTe2 exhibits multiple charge density wave (CDW) phases, mainly (4 × 4) and (4 × 1). Here we report facile dynamic and tens-of-nanometer scale switching between these CDW phases with gentle bias pulses in scanning tunneling microscopy. Bias pulses purposely stimulate a reversible random CDW symmetry change between the isotropic (4 × 4) and anisotropic (4 × 1) CDWs, as well as CDW phase slips and rotation. The switching threshold of ∼1.0 V is independent of bias polarity, and the switching rate varies linearly with the tunneling current. Density functional theory calculations indicate that a coherent CDW phase switching incurs an energy barrier of ∼2.0-3.0 eV per (4 × 4) unit cell. While there is a challenge in understanding the observed large-area CDW random fluttering, we provide some possible explanations. The ability to manipulate electronic CDW phases sheds new light on tailoring CDW properties on demand.
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Affiliation(s)
- Ulysse Chazarin
- Université Paris Cité, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
- Center for Condensed Matter Science (CCMS), National Taiwan University, 11106 Taipei, Taiwan ROC
| | - Mahé Lezoualc'h
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Abhishek Karn
- Center for Condensed Matter Science (CCMS), National Taiwan University, 11106 Taipei, Taiwan ROC
| | - Jyh-Ping Chou
- Department of Physics, National Changhua University of Education, 50007 Chuanghua City, Taiwan ROC
| | - Woei Wu Pai
- Center for Condensed Matter Science (CCMS), National Taiwan University, 11106 Taipei, Taiwan ROC
| | - Cyril Chacon
- Université Paris Cité, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - Yann Girard
- Université Paris Cité, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - Vincent Repain
- Université Paris Cité, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - Amandine Bellec
- Université Paris Cité, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - Sylvie Rousset
- Université Paris Cité, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - César González
- Departamento de Física de Materiales, Universidad Complutense de Madrid, E-28040 Madrid, Spain
- Instituto de Magnetismo Aplicado UCM-ADIF, Vía de Servicio A-6, 900, E-28232 Las Rozas de Madrid, Spain
| | - Alexander Smogunov
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Jérôme Lagoute
- Université Paris Cité, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
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2
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Fan Y, Tao S, Pitié S, Liu C, Zhao C, Seydou M, Dappe YJ, Low PJ, Nichols RJ, Yang L. Destructive quantum interference in meta-oligo(phenyleneethynylene) molecular wires with gold-graphene heterojunctions. Nanoscale 2023; 16:195-204. [PMID: 38050747 DOI: 10.1039/d3nr04012g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2023]
Abstract
Quantum interference (QI) is well recognised as a significant contributing factor to the magnitude of molecular conductance values in both single-molecule and large area junctions. Numerous structure-property relationship studies have shown that para-connected oligo(phenyleneethynylene) (OPE) based molecular wires exemplify the impact of constructive quantum interference (CQI), whilst destructive quantum interference (DQI) effects are responsible for the orders of magnitude lower conductance of analogous meta-contacted OPE derivatives, despite the somewhat shorter effective tunnelling distance. Since molecular conductance is related to the value of the transmission function, evaluated at the electrode Fermi energy, T(EF), which in turn is influenced by the presence and relative energy of (anti)resonances, it follows that the relative single-molecule conductance of para- and meta-contacted OPE-type molecules is tuned both by the anchor group and the nature of the electrode materials used in the construction of molecular junctions (gold|molecule|gold vs. gold|molecule|graphene). It is shown here that whilst amine-contacted junctions show little influence of the electrode material on molecular conductance due to the similar electrode-molecule coupling through this anchor group to both types of electrodes, the weaker coupling between thiomethyl and ethynyl anchors and the graphene substrate electrode results in a relative enhancement of the DQI effect. This work highlights an additional parameter space to explore QI effects and establishes a new working model based on the electrode materials and anchor groups in modulating QI effects beyond the chemical structure of the molecular backbone.
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Affiliation(s)
- Yinqi Fan
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China.
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Shuhui Tao
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China.
- NUS (Chongqing) Research Institute, Chongqing, China
| | - Sylvain Pitié
- Applied Quantum Chemistry Group, E4, IC2MP, UMR 7285 Poitiers University CNRS, 86073 Poitiers, France
| | - Chenguang Liu
- Department of Electrical and Electronic Engineering, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China
| | - Chun Zhao
- Department of Electrical and Electronic Engineering, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China
| | | | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Paul J Low
- School of Molecular Sciences, University of Western Australia, 35 Stirling Highway, 6009 Crawley, Australia
| | - Richard J Nichols
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Li Yang
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China.
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
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3
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Snegir S, Dappe YJ, Sysoiev D, Huhn T, Scheer E. Nonuniform STM Contrast of Self-Assembled Tri- n-octyl-triazatriangulenium Tetrafluoroborate on HOPG. ACS Omega 2023; 8:38766-38772. [PMID: 37867726 PMCID: PMC10586247 DOI: 10.1021/acsomega.3c06454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 09/21/2023] [Indexed: 10/24/2023]
Abstract
We have assembled 4,8,12-tri-n-octyl-4,8,12-triazatrianguleniumtetrafluoroborate (TATA-BF4) on highly oriented pyrolytic graphite (HOPG) and have studied the structure and tunneling properties of this self-assembled monolayer (SAM) using scanning tunneling microscopy (STM) under ambient conditions. We show that the triazatriangulenium cations TATA+ form hexagonally packed structures driven by the interaction between the aromatic core and the HOPG lattice, as evidenced by density functional theory (DFT) modeling. According to the DFT results, the three alkyl chains of the platform tend to follow the main crystallographic directions of HOPG, leading to a different STM appearance. The STM contrast of the SAM shows that the monolayer is formed by two types of species, namely, TATA+ with BF4- counterions on top and without them. The cationic TATA+ platform gives rise to a seemingly higher appearance than neutral TATA-BF4, in contrast to observations made on metallic substrates. The variation of the STM tunneling parameters does not change the relative difference of contrast, revealing the stability of both species on HOPG. DFT calculations show that TATA-BF4 on HOPG has sufficient binding energy to resist dissociation into TATA+ and BF4-, which might occur under the action of the electric field in the tunneling gap during STM scanning.
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Affiliation(s)
- Sergii Snegir
- Department
of Physics, University of Konstanz, Universitätsstraße 10, Konstanz 78464, Germany
| | - Yannick J. Dappe
- SPEC,
CEA, CNRS, Université Paris-Saclay, CEA Saclay, Gif-sur-Yvette Cédex 91191, France
| | - Dmytro Sysoiev
- Department
of Chemistry, University of Konstanz, Universitätsstraße 10, Konstanz 78464, Germany
| | - Thomas Huhn
- Department
of Chemistry, University of Konstanz, Universitätsstraße 10, Konstanz 78464, Germany
| | - Elke Scheer
- Department
of Physics, University of Konstanz, Universitätsstraße 10, Konstanz 78464, Germany
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4
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Lorentzen AB, Bouatou M, Chacon C, Dappe YJ, Lagoute J, Brandbyge M. Quantum Transport in Large-Scale Patterned Nitrogen-Doped Graphene. Nanomaterials (Basel) 2023; 13:2556. [PMID: 37764585 PMCID: PMC10538011 DOI: 10.3390/nano13182556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 09/08/2023] [Accepted: 09/10/2023] [Indexed: 09/29/2023]
Abstract
It has recently been demonstrated how the nitrogen dopant concentration in graphene can be controlled spatially on the nano-meter scale using a molecular mask. This technique may be used to create ballistic electron optics-like structures of high/low doping regions; for example, to focus electron beams, harnessing the quantum wave nature of the electronic propagation. Here, we employ large-scale Greens function transport calculations based on a tight-binding approach. We first benchmark different tight-binding models of nitrogen in graphene with parameters based on density functional theory (DFT) and the virtual crystal approximation (VCA). Then, we study theoretically how the random distribution within the masked regions and the discreteness of the nitrogen scattering centers impact the transport behavior of sharp n-p and n-n' interfaces formed by different, realistic nitrogen concentrations. We investigate how constrictions for the current can be realized by patterned high/low doping regions with experimentally feasible nitrogen concentrations. The constrictions can guide the electronic current, while the quantized conductance is significantly washed out due to the nitrogen scattering. The implications for device design is that a p-n junction with nitrogen corrugation should still be viable for current focusing. Furthermore, a guiding channel with less nitrogen in the conducting canal preserves more features of quantized conductance and, therefore, its low-noise regime.
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Affiliation(s)
| | - Mehdi Bouatou
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS-Université Paris Cité, 10 Rue Alice Domon et Léonie Duquet, CEDEX 13, 75205 Paris, France; (M.B.); (C.C.); (J.L.)
| | - Cyril Chacon
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS-Université Paris Cité, 10 Rue Alice Domon et Léonie Duquet, CEDEX 13, 75205 Paris, France; (M.B.); (C.C.); (J.L.)
| | - Yannick J. Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, CEDEX, 91191 Gif-sur-Yvette, France;
| | - Jérôme Lagoute
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS-Université Paris Cité, 10 Rue Alice Domon et Léonie Duquet, CEDEX 13, 75205 Paris, France; (M.B.); (C.C.); (J.L.)
| | - Mads Brandbyge
- Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark;
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5
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Stanescu S, Alun T, Dappe YJ, Ihiawakrim D, Ersen O, Stanescu D. Enhancement of the Solar Water Splitting Efficiency Mediated by Surface Segregation in Ti-Doped Hematite Nanorods. ACS Appl Mater Interfaces 2023. [PMID: 37219355 DOI: 10.1021/acsami.3c02131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Band engineering is employed thoroughly and targets technologically scalable photoanodes for solar water splitting applications. Complex and costly recipes are necessary, often for average performances. Here, we report simple photoanode growth and thermal annealing with effective band engineering results. By comparing Ti-doped hematite photoanodes annealed under nitrogen to photoanodes annealed in air, we found a strongly enhanced photocurrent of more than 200% in the first case. Using electrochemical impedance spectroscopy and synchrotron X-ray spectromicroscopy, we demonstrate that oxidized surface states and increased density of charge carriers are responsible for the enhanced photoelectrochemical (PEC) activity. Surface states are found to be related to the formation of pseudo-brookite clusters by surface Ti segregation. Spectro-ptychography is used for the first time at the Ti L3 absorption edge to isolate Ti chemical coordination arising from pseudo-brookite cluster contribution. Correlated with electron microscopy investigation and density functional theory calculations, the synchrotron spectromicroscopy data unambiguously prove the origin of enhanced PEC activity of N2-annealed Ti-doped hematite nanorods. Finally, we present here a handy and cheap surface engineering method beyond the known oxygen vacancy doping, allowing a net gain in the PEC activity for the hematite-based photoanodes.
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Affiliation(s)
- Stefan Stanescu
- Synchrotron SOLEIL, L'Orme des Merisiers, Départementale 128, 91190 Saint-Aubin, France
| | - Théo Alun
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Dris Ihiawakrim
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS UMR 7504, 23 Rue du Loess, BP43, 67034 Strasbourg, France
| | - Ovidiu Ersen
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS UMR 7504, 23 Rue du Loess, BP43, 67034 Strasbourg, France
| | - Dana Stanescu
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
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6
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Neziri E, Zhang W, Smogunov A, Mayne AJ, Kara A, Dappe YJ, Oughaddou H. Structural properties of Bi/Au(110). Nanotechnology 2023; 34:235601. [PMID: 36848665 DOI: 10.1088/1361-6528/acbf55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
Atomically thin bismuth films (2D Bi) are becoming a promising research area due to their unique properties and their wide variety of applications in spintronics, electronic and optoelectronic devices. We report on the structural properties of Bi on Au(110), explored by low-energy electron diffraction (LEED), scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. At a Bi coverage lower than one monolayer (1 ML) various reconstructions are observed, we focus on Bi/Au(110)-c(2 × 2) reconstruction (at 0.5 ML) and Bi/Au(110)-(3 × 3) structure (at 0.66 ML). We propose models for both structures based on STM measurements and further confirm by DFT calculations.
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Affiliation(s)
- Egzona Neziri
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, F-91405 Orsay, France
| | - Wei Zhang
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, F-91405 Orsay, France
| | - Alexander Smogunov
- Université Paris-Saclay, CNRS, CEA, Service de Physique de l'Etat Condensé, F-91191 Gif-sur Yvette, France
| | - Andrew J Mayne
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, F-91405 Orsay, France
| | - Abdelkader Kara
- Department of Physics, University of Central Florida, Orlando, FL 32816, United States of America
- IRMC, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Yannick J Dappe
- Université Paris-Saclay, CNRS, CEA, Service de Physique de l'Etat Condensé, F-91191 Gif-sur Yvette, France
| | - Hamid Oughaddou
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, F-91405 Orsay, France
- Département de Physique, CY Cergy Paris Université, F-95031 Cergy-Pontoise Cedex, France
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7
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Trasobares J, Martín-Romano JC, Khaliq MW, Ruiz-Gómez S, Foerster M, Niño MÁ, Pedraz P, Dappe YJ, de Ory MC, García-Pérez J, Acebrón M, Osorio MR, Magaz MT, Gomez A, Miranda R, Granados D. Hybrid molecular graphene transistor as an operando and optoelectronic platform. Nat Commun 2023; 14:1381. [PMID: 36914623 PMCID: PMC10011542 DOI: 10.1038/s41467-023-36714-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 02/13/2023] [Indexed: 03/16/2023] Open
Abstract
Lack of reproducibility hampers molecular devices integration into large-scale circuits. Thus, incorporating operando characterization can facilitate the understanding of multiple features producing disparities in different devices. In this work, we report the realization of hybrid molecular graphene field effect transistors (m-GFETs) based on 11-(Ferrocenyl)undecanethiol (FcC11SH) micro self-assembled monolayers (μSAMs) and high-quality graphene (Gr) in a back-gated configuration. On the one hand, Gr enables redox electron transfer, avoids molecular degradation and permits operando spectroscopy. On the other hand, molecular electrode decoration shifts the Gr Dirac point (VDP) to neutrality and generates a photocurrent in the Gr electron conduction regime. Benefitting from this heterogeneous response, the m-GFETs can implement optoelectronic AND/OR logic functions. Our approach represents a step forward in the field of molecular scale electronics with implications in sensing and computing based on sustainable chemicals.
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Affiliation(s)
- Jorge Trasobares
- IMDEA-Nanociencia, Cantoblanco, Madrid, 28049, Spain. .,Department of Biodiversity, Ecology and Evolution (Biomathematics), Universidad Complutense de Madrid, Madrid, 28040, Spain.
| | | | - Muhammad Waqas Khaliq
- ALBA Synchrotron, Carrer de la llum 2-26, Cerdanyola del Valles, 08290, Spain.,Department of Condensed Matter Physics, University of Barcelona, Barcelona, Spain
| | - Sandra Ruiz-Gómez
- ALBA Synchrotron, Carrer de la llum 2-26, Cerdanyola del Valles, 08290, Spain
| | - Michael Foerster
- ALBA Synchrotron, Carrer de la llum 2-26, Cerdanyola del Valles, 08290, Spain
| | - Miguel Ángel Niño
- ALBA Synchrotron, Carrer de la llum 2-26, Cerdanyola del Valles, 08290, Spain
| | | | - Yannick J Dappe
- Centro de Astrobiología (CSIC-INTA), Torrejón de Ardoz, 28850, Spain
| | | | | | - María Acebrón
- IMDEA-Nanociencia, Cantoblanco, Madrid, 28049, Spain
| | | | | | - Alicia Gomez
- Centro de Astrobiología (CSIC-INTA), Torrejón de Ardoz, 28850, Spain
| | - Rodolfo Miranda
- SPEC, CEA, CNRS Université Paris-Saclay, Gif-sur-Yvette, 91191, France.,Dpto. de Física de la Materia Condensada, Universidad Autónoma de Madrid, Cantoblanco, Spain
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8
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Tao S, Zhang Q, Pitie S, Liu C, Fan Y, Zhao C, Seydou M, Dappe YJ, Nichols RJ, Yang L. Revealing conductance variation of molecular junctions based on an unsupervised data analysis approach. Electrochim Acta 2023. [DOI: 10.1016/j.electacta.2023.142225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
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9
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Shaya J, Ribierre JC, Correia G, Dappe YJ, Mathevet F, Mager L, Heinrich B, Méry S. Control of the Organization of 4,4'-bis(carbazole)-1,1'-biphenyl (CBP) Molecular Materials through Siloxane Functionalization. Molecules 2023; 28:molecules28052038. [PMID: 36903284 PMCID: PMC10003964 DOI: 10.3390/molecules28052038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/10/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023] Open
Abstract
We show that through the introduction of short dimethylsiloxane chains, it was possible to suppress the crystalline state of CBP in favor of various types of organization, transitioning from a soft crystal to a fluid liquid crystal mesophase, then to a liquid state. Characterized by X-ray scattering, all organizations reveal a similar layered configuration in which layers of edge-on lying CBP cores alternate with siloxane. The difference between all CBP organizations essentially lay on the regularity of the molecular packing that modulates the interactions of neighboring conjugated cores. As a result, the materials show quite different thin film absorption and emission properties, which could be correlated to the features of the chemical architectures and the molecular organizations.
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Affiliation(s)
- Janah Shaya
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS, Strasbourg University, UMR 7504, 23 rue du Loess, 67034 Strasbourg, France
- Department of Chemistry, College of Arts and Sciences, Khalifa University, Abu Dhabi P.O. Box 127788, United Arab Emirates
- College of Medicine and Health Sciences, Khalifa University, Abu Dhabi P.O. Box 127788, United Arab Emirates
| | - Jean-Charles Ribierre
- Service de Physique de l’État Condensé, CEA CNRS UMR 3680, Université Paris Saclay, 91191 Gif-sur-Yvette, France
| | - Gabriel Correia
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS, Strasbourg University, UMR 7504, 23 rue du Loess, 67034 Strasbourg, France
| | - Yannick J. Dappe
- Service de Physique de l’État Condensé, CEA CNRS UMR 3680, Université Paris Saclay, 91191 Gif-sur-Yvette, France
| | - Fabrice Mathevet
- Institut Parisien de Chimie Moléculaire (IPCM), CNRS, Sorbonne University, 4 Place Jussieu, 75005 Paris, France
- Center for Organic Photonics and Electronics Research (OPERA), Department of Applied Chemistry, Kyushu Universty, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
| | - Loïc Mager
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS, Strasbourg University, UMR 7504, 23 rue du Loess, 67034 Strasbourg, France
| | - Benoît Heinrich
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS, Strasbourg University, UMR 7504, 23 rue du Loess, 67034 Strasbourg, France
- Correspondence: (B.H.); (S.M.)
| | - Stéphane Méry
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS, Strasbourg University, UMR 7504, 23 rue du Loess, 67034 Strasbourg, France
- Correspondence: (B.H.); (S.M.)
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10
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Li D, Tong Y, Bairagi K, Kelai M, Dappe YJ, Lagoute J, Girard Y, Rousset S, Repain V, Barreteau C, Brandbyge M, Smogunov A, Bellec A. Negative Differential Resistance in Spin-Crossover Molecular Devices. J Phys Chem Lett 2022; 13:7514-7520. [PMID: 35944010 DOI: 10.1021/acs.jpclett.2c01934] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We demonstrate, based on low-temperature scanning tunneling microscopy (STM) and spectroscopy, a pronounced negative differential resistance (NDR) in spin-crossover (SCO) molecular devices, where a FeII SCO molecule is deposited on surfaces. The STM measurements reveal that the NDR is robust with respect to substrate materials, temperature, and the number of SCO layers. This indicates that the NDR is intrinsically related to the electronic structure of the SCO molecule. Experimental results are supported by density functional theory (DFT) with nonequilibrium Green's function (NEGF) calculations and a generic theoretical model. While the DFT+NEGF calculations reproduce NDR for a special atomically sharp STM tip, the effect is attributed to the energy-dependent tip density of states rather than the molecule itself. We, therefore, propose a Coulomb blockade model involving three molecular orbitals with very different spatial localization as suggested by the molecular electronic structure.
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Affiliation(s)
- Dongzhe Li
- Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
- CEMES, Université de Toulouse, CNRS, 29 rue Jeanne Marvig, F-31055 Toulouse, France
| | - Yongfeng Tong
- Université Paris Cité, CNRS, Laboratoire Matériaux et Phénomènes Quantiques UMR7162, 75013 Paris, France
| | - Kaushik Bairagi
- Université Paris Cité, CNRS, Laboratoire Matériaux et Phénomènes Quantiques UMR7162, 75013 Paris, France
| | - Massine Kelai
- Université Paris Cité, CNRS, Laboratoire Matériaux et Phénomènes Quantiques UMR7162, 75013 Paris, France
| | - Yannick J Dappe
- Université Paris-Saclay, CEA, CNRS, SPEC, 91191 Gif-sur-Yvette, France
| | - Jérôme Lagoute
- Université Paris Cité, CNRS, Laboratoire Matériaux et Phénomènes Quantiques UMR7162, 75013 Paris, France
| | - Yann Girard
- Université Paris Cité, CNRS, Laboratoire Matériaux et Phénomènes Quantiques UMR7162, 75013 Paris, France
| | - Sylvie Rousset
- Université Paris Cité, CNRS, Laboratoire Matériaux et Phénomènes Quantiques UMR7162, 75013 Paris, France
| | - Vincent Repain
- Université Paris Cité, CNRS, Laboratoire Matériaux et Phénomènes Quantiques UMR7162, 75013 Paris, France
| | - Cyrille Barreteau
- Université Paris-Saclay, CEA, CNRS, SPEC, 91191 Gif-sur-Yvette, France
| | - Mads Brandbyge
- Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
- Center for Nanostructured Graphene, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | | | - Amandine Bellec
- Université Paris Cité, CNRS, Laboratoire Matériaux et Phénomènes Quantiques UMR7162, 75013 Paris, France
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11
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Tao S, Zhang Q, Vezzoli A, Zhao C, Zhao C, Higgins SJ, Smogunov A, Dappe YJ, Nichols RJ, Yang L. Electrochemical gating for single-molecule electronics with hybrid Au|graphene contacts. Phys Chem Chem Phys 2022; 24:6836-6844. [PMID: 35244656 DOI: 10.1039/d1cp05486d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The single-molecular conductance of a redox active viologen molecular bridge between Au|graphene electrodes has been studied in an electrochemical gating configuration in an ionic liquid medium. A clear "off-on-off" conductance switching behaviour has been achieved through gating of the redox state when the electrochemical potential is swept. The Au|viologen|graphene junctions show single-molecule conductance maxima centred close to the equilibrium redox potentials for both reduction steps. The peak conductance of Au|viologen|graphene junctions during the first reduction is significantly higher than that of previously measured Au|viologen|Au junctions. This shows that even though the central viologen moiety is not directly linked to the enclosing electrodes, substituting one gold contact for a graphene one nevertheless has a significant impact on junction conductance values. The experimental data was compared against two theoretical models, namely a phase coherent tunnelling and an incoherent "hopping" model. The former is a simple gating monoelectronic model within density functional theory (DFT) which discloses the charge state evolution of the molecule with electrode potential. The latter model is the collective Kuznetsov Ulstrup model for 2-step sequential charge transport through the redox centre in the adiabatic limit. The comparison of both models to the experimental data is discussed for the first time. This work opens perspectives for graphene-based molecular transistors with more effective gating and fundamental understanding of electrochemical electron transfer at the single molecular level.
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Affiliation(s)
- Shuhui Tao
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China. .,Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Qian Zhang
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China. .,Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Andrea Vezzoli
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Cezhou Zhao
- Department of Electrical and Electronic Engineering, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China
| | - Chun Zhao
- Department of Electrical and Electronic Engineering, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China
| | - Simon J Higgins
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Alexander Smogunov
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex, France
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex, France
| | - Richard J Nichols
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Li Yang
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China. .,Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
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12
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Pitié S, Seydou M, Dappe YJ, Martin P, Maurel F, Lacroix JC. Insights on asymmetric BTB-based molecular junctions: Effect of electrode coupling. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2021.139273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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13
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Baby A, Marcaud G, Dappe YJ, D'Angelo M, Cantin JL, Silly M, Fratesi G. Phthalocyanine reactivity and interaction on the 6H-SiC(0001)-(3×3) surface by core-level experiments and simulations. Phys Chem Chem Phys 2022; 24:14937-14946. [DOI: 10.1039/d2cp00750a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The adsorption of phthalocyanine (H2Pc) on the 6H-SiC(0001)-(3×3) surface is investigated using X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure spectroscopy (NEXAFS), and density functional theory (DFT) calculations....
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14
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Quertite K, Enriquez H, Trcera N, Bendounan A, Mayne AJ, Dujardin G, El Kenz A, Benyoussef A, Dappe YJ, Kara A, Oughaddou H. Electron beam analysis induces Cl vacancy defects in a NaCl thin film. Nanotechnology 2021; 33:095706. [PMID: 34814126 DOI: 10.1088/1361-6528/ac3c79] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 11/23/2021] [Indexed: 06/13/2023]
Abstract
This work reports on the electron-induced modification of NaCl thin film grown on Ag(110). We show using low energy electron diffraction that electron beam bombardment leads to desorption and formation of Cl vacancy defects on NaCl surface. The topographic structure of these defects is studied using scanning tunneling microscopy (STM) showing the Cl defects as depressions on the NaCl surface. Most of the observed defects are mono-atomic vacancies and are located on flat NaCl terraces. Auger electron spectroscopy confirms the effect of electron exposure on NaCl thin films showing Cl atoms desorption from the surface. Using density functional theory taken into account the van der Waals dispersion interactions, we confirm the observed experimental STM measurements with STM simulation. Furthermore, comparing the adsorption of defect free NaCl and defective NaCl monolayer on Ag(110) surfaces, we found an increase of the adhesion energy and the charge transfer between the NaCl film and the substrate due to the Cl vacancy. In details, the adhesion energy increases between the NaCl film and the metallic Ag substrate from 30.4 meV Å-2for the NaCl film without Cl vacancy and from 39.5 meV Å-2for NaCl film with a single Cl vacancy. The charge transfer from the NaCl film to the Ag substrate is enhanced when the vacancy is created, from 0.63e-to 1.25e-.
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Affiliation(s)
- Khalid Quertite
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay (ISMO), Bât. 520, F-91405 Orsay, France
- Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, B.P. 48, F-91192 Gif-sur-Yvette Cedex, France
- LaMCScI, Faculté des Sciences, Université Mohammed V-Agdal, 10100, Rabat, Morocco
| | - Hanna Enriquez
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay (ISMO), Bât. 520, F-91405 Orsay, France
| | - Nicolas Trcera
- Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, B.P. 48, F-91192 Gif-sur-Yvette Cedex, France
| | - Azzedine Bendounan
- Synchrotron Soleil, L'Orme des Merisiers, Saint-Aubin, B.P. 48, F-91192 Gif-sur-Yvette Cedex, France
| | - Andrew J Mayne
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay (ISMO), Bât. 520, F-91405 Orsay, France
| | - Gérald Dujardin
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay (ISMO), Bât. 520, F-91405 Orsay, France
| | - Abdallah El Kenz
- LaMCScI, Faculté des Sciences, Université Mohammed V-Agdal, 10100, Rabat, Morocco
| | - Abdelilah Benyoussef
- LaMCScI, Faculté des Sciences, Université Mohammed V-Agdal, 10100, Rabat, Morocco
- Hassan II Academy of Sciences and Technology, Rabat, Morocco
| | - Yannick J Dappe
- Université Paris-Saclay, CEA, CNRS, SPEC, F-91191 Gif-sur-Yvette Cedex, France
| | - Abdelkader Kara
- Department of Physics, University of Central Florida, Orlando, FL 32816, United States of America
| | - Hamid Oughaddou
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay (ISMO), Bât. 520, F-91405 Orsay, France
- Département de Physique, CY, Cergy Paris Université, F-95031 Cergy-Pontoise Cedex, France
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15
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Gao T, He C, Liu C, Fan Y, Zhao C, Zhao C, Su W, Dappe YJ, Yang L. Oligothiophene molecular wires at graphene-based molecular junctions. Phys Chem Chem Phys 2021; 23:21163-21171. [PMID: 34528653 DOI: 10.1039/d1cp03050g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The use of graphene as a new type of electrode at molecular junctions has led to a renewal of molecular electronics. Indeed, the symmetry breaking induced by the graphene electrode yields different electronic behaviors at the molecular junction and in particular enhanced conductance for longer molecules. In this respect, several studies involving different molecular backbones and anchoring groups have been performed. Here in the same line, we consider oligopthiophene based hybrid gold-graphene junctions and we measure their electrical properties using the STM-I(s) method in order to determine their attenuation factor and the effect of specific anchoring groups. The results are supported by density functional theory (DFT) calculations, and exhibit a similar behavior to what is observed at alkane-based junctions.
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Affiliation(s)
- Tingwei Gao
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China. .,Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Chunhui He
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China. .,Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Chenguang Liu
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China.
| | - Yinqi Fan
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China. .,Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Cezhou Zhao
- Department of Electrical and Electronic Engineering, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China
| | - Chun Zhao
- Department of Electrical and Electronic Engineering, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China
| | - Weitao Su
- College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou, 310018, China
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, Gif-sur-Yvette Cedex 91191, France
| | - Li Yang
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, China. .,Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
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16
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Zhang W, Enriquez H, Tong Y, Mayne AJ, Bendounan A, Smogunov A, Dappe YJ, Kara A, Dujardin G, Oughaddou H. Flat epitaxial quasi-1D phosphorene chains. Nat Commun 2021; 12:5160. [PMID: 34453043 PMCID: PMC8397792 DOI: 10.1038/s41467-021-25262-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 07/21/2021] [Indexed: 02/07/2023] Open
Abstract
The emergence of peculiar phenomena in 1D phosphorene chains (P chains) has been proposed in theoretical studies, notably the Stark and Seebeck effects, room temperature magnetism, and topological phase transitions. Attempts so far to fabricate P chains, using the top-down approach starting from a few layers of bulk black phosphorus, have failed to produce reliably precise control of P chains. We show that molecular beam epitaxy gives a controllable bottom-up approach to grow atomically thin, crystalline 1D flat P chains on a Ag(111) substrate. Scanning tunneling microscopy, angle-resolved photoemission spectroscopy, and density functional theory calculations reveal that the armchair-shaped chains are semiconducting with an intrinsic 1.80 ± 0.20 eV band gap. This could make these P chains an ideal material for opto-electronic devices.
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Affiliation(s)
- Wei Zhang
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, Orsay, France
| | - Hanna Enriquez
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, Orsay, France
| | - Yongfeng Tong
- TEMPO Beamline, Synchrotron SOLEIL, Gif-sur-Yvette, Cedex, France
| | - Andrew J Mayne
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, Orsay, France
| | | | - Alex Smogunov
- Université Paris-Saclay, CNRS, CEA, Service de Physique de l'Etat Condensé, Gif-sur-Yvette, France
| | - Yannick J Dappe
- Université Paris-Saclay, CNRS, CEA, Service de Physique de l'Etat Condensé, Gif-sur-Yvette, France
| | - Abdelkader Kara
- Department of Physics, University of Central Florida, Orlando, FL, USA
| | - Gérald Dujardin
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, Orsay, France
| | - Hamid Oughaddou
- Université Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, Orsay, France.
- Département de Physique, CY Cergy Paris Université, Cergy-Pontoise, Cedex, France.
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17
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Snegir S, Dappe YJ, Sysoiev D, Pluchery O, Huhn T, Scheer E. Where do the counterions go? Tip-induced dissociation of self-assembled triazatriangulenium-based molecules on Au(111). Phys Chem Chem Phys 2021; 23:9930-9937. [PMID: 33861285 DOI: 10.1039/d1cp00221j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chemical coupling of functional molecules on top of the so-called platform molecules allows the formation of functional self-assembled monolayers (SAMs). An often-used example of such a platform is triazatriangulenium (TATA), which features an extended aromatic core providing good electronic contact to the underlying metal surface. Here, we present a study of the SAM formation of a TATA platform on Au(111) employing scanning tunneling microscopy (STM) under ambient atmospheric conditions. In solution, the TATA platform is stabilized by BF4 counterions, while after deposition on a gold substrate, the localization of the BF4 counterions remains unknown. We used 1,2,4-trichlorobenzene as a solvent of TATA-BF4 to induce SAM formation on a heated (∼50 °C) Au substrate. We show by STM how to detect and distinguish TATA-BF4 from TATA platforms, which lost their BF4 counterions. Finally, we observe a change of the counterion position on the SAM during the STM scanning, which we explain by an electric-field-induced decrease of the electrostatic interaction in TATA-BF4 on the surface. We applied DFT calculations to reveal the influence of the gold lattice and the electric field of the STM tip on the stability of TATA-BF4 physisorbed on the surface.
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Affiliation(s)
- S Snegir
- Department of Physics, University of Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany.
| | - Y J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - D Sysoiev
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany
| | - O Pluchery
- Sorbonne Université, CNRS, Institut des NanoSciences de Paris (INSP), 4 place Jussieu, 75005 Paris, France
| | - T Huhn
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany
| | - E Scheer
- Department of Physics, University of Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany.
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18
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Zhang W, Enriquez H, Zhang X, Mayne AJ, Bendounan A, Dappe YJ, Kara A, Dujardin G, Oughaddou H. Blue phosphorene reactivity on the Au(111) surface. Nanotechnology 2020; 31:495602. [PMID: 32975225 DOI: 10.1088/1361-6528/abb26c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The synthesis of blue phosphorene by molecular beam epitaxy (MBE) has recently come under the spotlight due to its potential applications in electronic and optoelectronic devices. However, this synthesis remains a significant challenge. The surface reactivity between the P atoms and the Au atoms should be considered for the P/Au(111) system. In the MBE process, the temperature of the substrate is a key parameter for the growth of blue phosphorene. During the initial growth stage, irregularly shaped Phosphorus clusters grow on top of Au(111) surface at room temperature. When the substrate temperature is increased, these clusters transform into a phosphorene-like structure with a honeycomb lattice. An atom exchange reaction is observed between the P and first layer Au atoms under thermal activation at higher temperature, where the P atoms replace Au atoms to form a blue phosphorene structure within the top Au layer and at the step edges.
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Affiliation(s)
- Wei Zhang
- Universiteé Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - Hanna Enriquez
- Universiteé Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - Xuan Zhang
- School of Materials Science and Physics, China University of Mining and Technology, Xuzhou 221116, People's Republic of China
| | - Andrew J Mayne
- Universiteé Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - Azzedine Bendounan
- TEMPO Beamline, Synchrotron SOLEIL, L'Orme des Merisiers Saint-Aubin, B.P.48, 91192 Gif-sur-Yvette, France
| | - Yannick J Dappe
- Universiteé Paris-Saclay, CNRS, CEA, Service de Physique de l'Etat Condenseé, 91191 Gif-sur-Yvette, France
| | - Abdelkader Kara
- Department of Physics, University of Central Florida, Orlando, FL 32816, United States of America
| | - Gérald Dujardin
- Universiteé Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
| | - Hamid Oughaddou
- Universiteé Paris-Saclay, CNRS, Institut des Sciences Moléculaires d'Orsay, 91405 Orsay, France
- Département de physique, Université de Cergy-Pontoise, 95031, Cergy-Pontoise, France
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19
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Bouatou M, Harsh R, Joucken F, Chacon C, Repain V, Bellec A, Girard Y, Rousset S, Sporken R, Gao F, Brandbyge M, Dappe YJ, Barreteau C, Smogunov A, Lagoute J. Intraconfigurational Transition due to Surface-Induced Symmetry Breaking in Noncovalently Bonded Molecules. J Phys Chem Lett 2020; 11:9329-9335. [PMID: 33089985 DOI: 10.1021/acs.jpclett.0c02407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The interaction of molecules with surfaces plays a crucial role in the electronic and chemical properties of supported molecules and needs a comprehensive description of interfacial effects. Here, we unveil the effect of the substrate on the electronic configuration of iron porphyrin molecules on Au(111) and graphene, and we provide a physical picture of the molecule-surface interaction. We show that the frontier orbitals derive from different electronic states depending on the substrate. The origin of this difference comes from molecule-substrate orbital selective coupling caused by reduced symmetry and interaction with the substrate. The weak interaction on graphene keeps a ground state configuration close to the gas phase, while the stronger interaction on gold stabilizes another electronic solution. Our findings reveal the origin of the energy redistribution of molecular states for noncovalently bonded molecules on surfaces.
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Affiliation(s)
- Mehdi Bouatou
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - Rishav Harsh
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - Frédéric Joucken
- Research Center in Physics of Matter and Radiation (PMR), Université de Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium
| | - Cyril Chacon
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - Vincent Repain
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - Amandine Bellec
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - Yann Girard
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - Sylvie Rousset
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
| | - Robert Sporken
- Research Center in Physics of Matter and Radiation (PMR), Université de Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium
| | - Fei Gao
- Center for Nanostructured Graphene, Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Mads Brandbyge
- Center for Nanostructured Graphene, Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Cyrille Barreteau
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Alexander Smogunov
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Jérôme Lagoute
- Université de Paris, Laboratoire Matériaux et Phénomènes Quantiques, CNRS, F-75013 Paris, France
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20
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Bouatou M, Mondal S, Chacon C, Joucken F, Girard Y, Repain V, Bellec A, Rousset S, Narasimhan S, Sporken R, Dappe YJ, Lagoute J. Direct Observation of the Reduction of a Molecule on Nitrogen Pairs in Doped Graphene. Nano Lett 2020; 20:6908-6913. [PMID: 32830982 DOI: 10.1021/acs.nanolett.0c03030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Incorporating functional atomic sites in graphene is essential for realizing advanced two-dimensional materials. Doping graphene with nitrogen offers the opportunity to tune its chemical activity with significant charge redistribution occurring between molecules and substrate. The necessary atomic scale understanding of how this depends on the spatial distribution of dopants, as well as their positions relative to the molecule, can be provided by scanning tunneling microscopy. Here we show that a noncovalently bonded molecule such as CoPc undergoes a variable charge transfer when placed on N-doped graphene; on a nitrogen pair, it undergoes a redox reaction with an integral charge transfer whereas a lower fractional charge transfer occurs over a single nitrogen. Thus, the charge state of molecules can be tuned by suitably tailoring the conformation of dopant atoms.
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Affiliation(s)
- Mehdi Bouatou
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS, Université de Paris, F-75013, Paris, France
| | - Sourav Mondal
- Theoretical Sciences Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | - Cyril Chacon
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS, Université de Paris, F-75013, Paris, France
| | - Frédéric Joucken
- Research Center in Physics of Matter and Radiation (PMR), Université de Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium
| | - Yann Girard
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS, Université de Paris, F-75013, Paris, France
| | - Vincent Repain
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS, Université de Paris, F-75013, Paris, France
| | - Amandine Bellec
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS, Université de Paris, F-75013, Paris, France
| | - Sylvie Rousset
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS, Université de Paris, F-75013, Paris, France
| | - Shobhana Narasimhan
- Theoretical Sciences Unit and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | - Robert Sporken
- Research Center in Physics of Matter and Radiation (PMR), Université de Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex France
| | - Jérôme Lagoute
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS, Université de Paris, F-75013, Paris, France
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21
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Snegir S, Dappe YJ, Kapitanchuk OL, Coursault D, Lacaze E. Kinked row-induced chirality driven by molecule-substrate interactions. Phys Chem Chem Phys 2020; 22:7259-7267. [PMID: 32207467 DOI: 10.1039/c9cp06519a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Combining STM measurements on three different substrates (HOPG, MoS2, and Au[111]) together with DFT calculations allow for analysis of the origin of the self-assembly of 4-cyano-4'-n-decylbiphenyl (10CB) molecules into kinked row structures using a previously developed phenomenological model. This molecule has an alkyl chain with 10 carbons and a cyanobiphenyl group with a particularly large dipole moment. 10CB represents a toy model that we use here to unravel the relationship between the induced kinked structure, in particular the corresponding chirality expression, and the balanced intermolecular/molecule-substrate interaction. We show that the local ordered structure is driven by the typical alkyl chain/substrate interaction for HOPG and Au[111] and the cyanobiphenyl group/substrate interaction for MoS2. The strongest molecule/substrate interactions are observed for MoS2 and Au[111]. These strong interactions should have led to non-kinked, commensurate adsorbed structures. However, this latter appears impossible due to steric interactions between the neighboring cyanobiphenyl groups that lead to a fan-shape structure of the cyanobiphenyl packing on the three substrates. As a result, the kink-induced chirality is particularly large on MoS2 and Au[111]. A further breaking of symmetry is observed on Au[111] due to an asymmetry of the facing molecules in the rows induced by similar interactions with the substrate of both the alkyl chain and the cyanobiphenyl group. We calculate that the overall 10CB/Au[111] interaction is of the order of 2 eV per molecule. The close 10CB/MoS2 interaction, in contrast, is dominated by the cyanobiphenyl group, being particularly large possibly due to dipole-dipole interactions between the cyanobiphenyl groups and the MoS2 substrate.
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Affiliation(s)
- Sergii Snegir
- Sorbonne Université, Faculté des Sciences, CNRS, Institut des Nano-Sciences de Paris (INSP), 4 pl Jussieu 75005 Paris, France.
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22
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Dappe YJ, Almadori Y, Dau MT, Vergnaud C, Jamet M, Paillet C, Journot T, Hyot B, Pochet P, Grévin B. Charge transfers and charged defects in WSe 2/graphene-SiC interfaces. Nanotechnology 2020; 31:255709. [PMID: 32182596 DOI: 10.1088/1361-6528/ab8083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report on Kelvin probe force microscopy (KPFM) and density functional theory (DFT) investigations of charge transfers in vertical heterojunctions between tungsten diselenide (WSe2) layers and graphene on silicon carbide substrates. The experimental data reveal the existence of an interface dipole, which is shown by DFT to originate from the neutralization of the graphene n-doping by an electron transfer towards the transition metal dichalcogenide (TMD) layer. The relative vacuum level shift probed by KPFM between the TMD and the substrate stays constant when passing from monolayer to bilayer graphene, which confirms that the Schottky-Mott model can be rigorously applied to these interfaces by taking into account the charge transfer from the substrate to the TMD. DFT calculations show that the first TMD layer absorbs almost all the excess charges contained in the graphene, and that the second TMD layer shall not play a significant role in the electrostatics of the system. Negatively charged defect at the TMD edges contribute however to the electrostatic landscape probed by KPFM on both TMD layers.
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Affiliation(s)
- Y J Dappe
- SPEC, CEA, CNRS, Université Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex France
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23
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He C, Zhang Q, Gao T, Liu C, Chen Z, Zhao C, Zhao C, Nichols RJ, Dappe YJ, Yang L. Charge transport in hybrid platinum/molecule/graphene single molecule junctions. Phys Chem Chem Phys 2020; 22:13498-13504. [PMID: 32530005 DOI: 10.1039/d0cp01774d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The single molecule conductance of hybrid platinum/alkanedithiol/graphene junctions has been investigated with a focus on understanding the influence of employing two very different contact types. We call this an "anti-symmetric" configuration, with the two different contacts here being platinum and graphene, which respectively provide very different electronic coupling to the alkanedithiol bridge. The conductance of these junctions is experimentally investigated by using a non-contact scanning tunneling microscopy (STM) based method called the I(s) technique. These experimental determinations are supported by density functional theory (DFT) calculations. These alkanedithiol bridging molecules conduct electric current through the highest occupied molecular orbital (HOMO), and junctions formed with Pt/graphene electrode pairs are slightly more conductive than those formed with Au/graphene electrodes which we previously investigated. This is consistent with the lower work function of gold than that of platinum. The measured conductance decays exponentially with the length of the molecular bridge with a low tunneling decay constant, which has a similar value for Pt/graphene and Au/graphene electrode pairs, respectively. These new results underline the importance of the coupling asymmetry between the two electrodes, more than the type of the metal electrode itself. Importantly, the tunneling decay constant is much lower than that of alkanedithiols with the symmetrical equivalent, i.e. identical metal electrodes. We attribute this difference to the relatively weak van der Waals coupling at the graphene interface and the strong bond dipole at the Pt-S interface, resulting in a decrease in the potential barrier at the interface.
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Affiliation(s)
- Chunhui He
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China. and Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Qian Zhang
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China. and Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Tingwei Gao
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China. and Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Chenguang Liu
- Department of Electrical and Electronic Engineering, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China
| | - Zhenyu Chen
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Cezhou Zhao
- Department of Electrical and Electronic Engineering, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China
| | - Chun Zhao
- Department of Electrical and Electronic Engineering, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China
| | - Richard J Nichols
- Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
| | - Li Yang
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China. and Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, UK
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24
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Harsh R, Joucken F, Chacon C, Repain V, Girard Y, Bellec A, Rousset S, Sporken R, Smogunov A, Dappe YJ, Lagoute J. Controlling Hydrogen-Transfer Rate in Molecules on Graphene by Tunable Molecular Orbital Levels. J Phys Chem Lett 2019; 10:6897-6903. [PMID: 31638814 DOI: 10.1021/acs.jpclett.9b02902] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Molecular switches are building blocks of potential interest to store binary information, especially when they can be organized in periodic lattices. Among the variety of possible systems, switches based on hydrogen transfer are of special importance because they allow the switching operation to occur without severe conformational change that may interfere with neighboring molecular units. We have studied the excitation process of hydrogen transfer inside porphyrin molecules assembled on a graphene surface, using a low-temperature scanning tunneling microscope. We show that this hydrogen transfer is induced by an electronic resonant tunneling process through the molecular orbitals. Using nitrogen doping of graphene, we tune the rate of hydrogen transfer by shifting the molecular orbital energies owing to the charge transfer at nitrogen dopant sites in the graphene lattice. The control of the switching process allows the storage of information inside a molecular lattice, which is demonstrated by writing an artificial pattern inside a molecular island.
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Affiliation(s)
- Rishav Harsh
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
| | - Frédéric Joucken
- Research Center in Physics of Matter and Radiation (PMR) , Université de Namur , 61 Rue de Bruxelles , 5000 Namur , Belgium
| | - Cyril Chacon
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
| | - Vincent Repain
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
| | - Yann Girard
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
| | - Amandine Bellec
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
| | - Sylvie Rousset
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
| | - Robert Sporken
- Research Center in Physics of Matter and Radiation (PMR) , Université de Namur , 61 Rue de Bruxelles , 5000 Namur , Belgium
| | - Alexander Smogunov
- SPEC, CEA, CNRS , Université Paris-Saclay , CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Yannick J Dappe
- SPEC, CEA, CNRS , Université Paris-Saclay , CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Jérôme Lagoute
- Université de Paris , Laboratoire Matériaux et Phénomènes Quantiques, CNRS , F-75013 Paris , France
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25
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Li D, Dappe YJ, Smogunov A. Tuning spin filtering by anchoring groups in benzene derivative molecular junctions. J Phys Condens Matter 2019; 31:405301. [PMID: 31181563 DOI: 10.1088/1361-648x/ab2846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
One of the important issues of molecular spintronics is the control and manipulation of charge transport and, in particular, its spin polarization through single-molecule junctions. Using ab initio calculations, we explore spin-polarized electron transport across single benzene derivatives attached with six different anchoring groups (S, CH3S, COOH, CNH2NH, NC and NO2) to Ni(1 1 1) electrodes. We find that molecule-electrode coupling, conductance and spin polarization (SP) of electric current can be modified significantly by anchoring groups. In particular, a high spin polarization (SP > 80%) and a giant magnetoresistance (MR > 140%) can be achieved for NO2 terminations and, more interestingly, SP can be further enhanced (up to 90%) by a small voltage. The S and CH3S systems, on the contrary, exhibit rather low SP while intermediate values are found for COOH and CNH2NH groups. The results are analyzed in detail and explained by orbital symmetry arguments, hybridization and spatial localization of frontier molecular orbitals. We hope that our comparative and systematic studies will provide valuable quantitative information for future experimental measurements on that kind of systems and will be useful for designing high-performance spintronics devices.
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Affiliation(s)
- Dongzhe Li
- Department of Physics, University of Konstanz, 78457 Konstanz, Germany
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26
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Fourmental C, Mondal S, Banerjee R, Bellec A, Garreau Y, Coati A, Chacon C, Girard Y, Lagoute J, Rousset S, Boillot ML, Mallah T, Enachescu C, Barreteau C, Dappe YJ, Smogunov A, Narasimhan S, Repain V. Importance of Epitaxial Strain at a Spin-Crossover Molecule-Metal Interface. J Phys Chem Lett 2019; 10:4103-4109. [PMID: 31265299 DOI: 10.1021/acs.jpclett.9b01303] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Spin-crossover molecules are very appealing for use in multifunctional spintronic devices because of their ability to switch between high-spin and low-spin states with external stimuli such as voltage and light. In actual devices, the molecules are deposited on a substrate, which can modify their properties. However, surprisingly little is known about such molecule-substrate effects. Here we show for the first time, by grazing incidence X-ray diffraction, that an FeII spin-crossover molecular layer displays a well-defined epitaxial relationship with a metal substrate. Then we show, by both density functional calculations and a mechanoelastic model, that the resulting epitaxial strain and the related internal pressure can induce a partial spin conversion at low temperatures, which has indeed been observed experimentally. Our results emphasize the importance of substrate-induced spin state transitions and raise the possibility of exploiting them.
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Affiliation(s)
- Cynthia Fourmental
- Matériaux et Phénomènes Quantiques , Université de Paris, CNRS, UMR 7162 , 10 rue A. Domon et L. Duquet , 75013 Paris , France
| | - Sourav Mondal
- Theoretical Sciences Unit and School of Advanced Materials , Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur , Bangalore 560064 , India
| | - Rajdeep Banerjee
- Theoretical Sciences Unit and School of Advanced Materials , Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur , Bangalore 560064 , India
| | - Amandine Bellec
- Matériaux et Phénomènes Quantiques , Université de Paris, CNRS, UMR 7162 , 10 rue A. Domon et L. Duquet , 75013 Paris , France
| | - Yves Garreau
- Matériaux et Phénomènes Quantiques , Université de Paris, CNRS, UMR 7162 , 10 rue A. Domon et L. Duquet , 75013 Paris , France
- Synchrotron SOLEIL , L'Orme des Merisiers, Saint-Aubin , 91192 Gif sur Yvette , France
| | - Alessandro Coati
- Synchrotron SOLEIL , L'Orme des Merisiers, Saint-Aubin , 91192 Gif sur Yvette , France
| | - Cyril Chacon
- Matériaux et Phénomènes Quantiques , Université de Paris, CNRS, UMR 7162 , 10 rue A. Domon et L. Duquet , 75013 Paris , France
| | - Yann Girard
- Matériaux et Phénomènes Quantiques , Université de Paris, CNRS, UMR 7162 , 10 rue A. Domon et L. Duquet , 75013 Paris , France
| | - Jérôme Lagoute
- Matériaux et Phénomènes Quantiques , Université de Paris, CNRS, UMR 7162 , 10 rue A. Domon et L. Duquet , 75013 Paris , France
| | - Sylvie Rousset
- Matériaux et Phénomènes Quantiques , Université de Paris, CNRS, UMR 7162 , 10 rue A. Domon et L. Duquet , 75013 Paris , France
| | - Marie-Laure Boillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay , Univ Paris Sud, Université Paris-Saclay, CNRS, UMR 8182 , 91405 Orsay Cedex , France
| | - Talal Mallah
- Institut de Chimie Moléculaire et des Matériaux d'Orsay , Univ Paris Sud, Université Paris-Saclay, CNRS, UMR 8182 , 91405 Orsay Cedex , France
| | - Cristian Enachescu
- Faculty of Physics , Alexandru Ioan Cuza University of Iasi , Iasi 700506 , Romania
| | - Cyrille Barreteau
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Cedex Gif sur Yvette , France
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Cedex Gif sur Yvette , France
| | - Alexander Smogunov
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Cedex Gif sur Yvette , France
| | - Shobhana Narasimhan
- Theoretical Sciences Unit and School of Advanced Materials , Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur , Bangalore 560064 , India
| | - Vincent Repain
- Matériaux et Phénomènes Quantiques , Université de Paris, CNRS, UMR 7162 , 10 rue A. Domon et L. Duquet , 75013 Paris , France
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27
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He C, Zhang Q, Fan Y, Zhao C, Zhao C, Ye J, Dappe YJ, Nichols RJ, Yang L. Effect of Asymmetric Anchoring Groups on Electronic Transport in Hybrid Metal/Molecule/Graphene Single Molecule Junctions. Chemphyschem 2019; 20:1830-1836. [PMID: 31108024 DOI: 10.1002/cphc.201900424] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 05/17/2019] [Indexed: 11/08/2022]
Abstract
A combined experimental and theoretical study on molecular junctions with asymmetry in both the electrode type and in the anchoring group type is presented. A scanning tunnelling microscope is used to create the "asymmetric" Au-S-(CH2 )n-COOH-graphene molecular junctions and determine their conductance. The measurements are combined with electron transport calculations based on density functional theory (DFT) to analyze the electrical conductance and its length attenuation factor from a series of junctions of different molecular length (n). These results show an unexpected trend with a rather high conductance and a smaller attenuation factor for the Au-S-(CH2 )n -COOH-graphene configuration compared to the equivalent junction with the "symmetrical" COOH contacting using the HOOC-(CH2 )n -COOH series. Owing to the effect of the graphene electrode, the attenuation factor is also smaller than the one obtained for Au/Au electrodes. These results are interpreted through the relative molecule/electrode couplings and molecular level alignments as determined with DFT calculations. In an asymmetric junction, the electrical current flows through the less resistive conductance channel, similarly to what is observed in the macroscopic regime.
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Affiliation(s)
- Chunhui He
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China.,Department of Chemistry, University of Liverpool, Liverpool, L697ZD, UK
| | - Qian Zhang
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China.,Department of Chemistry, University of Liverpool, Liverpool, L697ZD, UK
| | - Yinqi Fan
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China.,Department of Chemistry, University of Liverpool, Liverpool, L697ZD, UK
| | - Cezhou Zhao
- Department of Electrical and Electronic Engineering, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China
| | - Chun Zhao
- Department of Electrical and Electronic Engineering, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China
| | - Jingyao Ye
- Department of Inorganic Chemistry, Copenhagen University, Universitetparken 21, Copenhagen, Denmark
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette, Cedex, France
| | - Richard J Nichols
- Department of Chemistry, University of Liverpool, Liverpool, L697ZD, UK
| | - Li Yang
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, 215123, Suzhou, China.,Department of Chemistry, University of Liverpool, Liverpool, L697ZD, UK
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28
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Kremer G, Alvarez Quiceno JC, Lisi S, Pierron T, González C, Sicot M, Kierren B, Malterre D, Rault JE, Le Fèvre P, Bertran F, Dappe YJ, Coraux J, Pochet P, Fagot-Revurat Y. Electronic Band Structure of Ultimately Thin Silicon Oxide on Ru(0001). ACS Nano 2019; 13:4720-4730. [PMID: 30916924 DOI: 10.1021/acsnano.9b01028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Silicon oxide can be formed in a crystalline form, when prepared on a metallic substrate. It is a candidate support catalyst and possibly the ultimately thin version of a dielectric host material for two-dimensional materials and heterostructures. We determine the atomic structure and chemical bonding of the ultimately thin version of the oxide, epitaxially grown on Ru(0001). In particular, we establish the existence of two sublattices defined by metal-oxygen-silicon bridges involving inequivalent substrate sites. We further discover four electronic bands below the Fermi level, at high binding energy, two of them having a linear dispersion at their crossing K point (Dirac cones) and two others forming semiflat bands. While the latter two correspond to hybridized states between the oxide and the metal, the former relate to the topmost silicon-oxygen plane, which is not directly coupled to the substrate. Our analysis is based on high-resolution X-ray photoelectron spectroscopy, angle-resolved photoemission spectroscopy, scanning tunneling microscopy, and density functional theory calculations.
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Affiliation(s)
- Geoffroy Kremer
- Institut Jean Lamour , UMR 7198, CNRS-Université de Lorraine, Campus ARTEM, 2 Allée André Guinier , BP 50840, 54011 Nancy , France
| | | | - Simone Lisi
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble , France
| | - Thomas Pierron
- Institut Jean Lamour , UMR 7198, CNRS-Université de Lorraine, Campus ARTEM, 2 Allée André Guinier , BP 50840, 54011 Nancy , France
| | - César González
- Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Facultad de Ciencias , Universidad Autónoma de Madrid , E-28049 Madrid , Spain
| | - Muriel Sicot
- Institut Jean Lamour , UMR 7198, CNRS-Université de Lorraine, Campus ARTEM, 2 Allée André Guinier , BP 50840, 54011 Nancy , France
| | - Bertrand Kierren
- Institut Jean Lamour , UMR 7198, CNRS-Université de Lorraine, Campus ARTEM, 2 Allée André Guinier , BP 50840, 54011 Nancy , France
| | - Daniel Malterre
- Institut Jean Lamour , UMR 7198, CNRS-Université de Lorraine, Campus ARTEM, 2 Allée André Guinier , BP 50840, 54011 Nancy , France
| | - Julien E Rault
- Synchrotron SOLEIL , Saint-Aubin , BP 48, F-91192 Gif-sur-Yvette Cedex, France
| | - Patrick Le Fèvre
- Synchrotron SOLEIL , Saint-Aubin , BP 48, F-91192 Gif-sur-Yvette Cedex, France
| | - François Bertran
- Synchrotron SOLEIL , Saint-Aubin , BP 48, F-91192 Gif-sur-Yvette Cedex, France
| | - Yannick J Dappe
- SPEC, CEA, CNRS , Université Paris-Saclay , CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Johann Coraux
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble , France
| | - Pascal Pochet
- Laboratoire de Simulation Atomistique , Univ. Grenoble Alpes & CEA , 38054 Grenoble , France
| | - Yannick Fagot-Revurat
- Institut Jean Lamour , UMR 7198, CNRS-Université de Lorraine, Campus ARTEM, 2 Allée André Guinier , BP 50840, 54011 Nancy , France
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29
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Abstract
Within the framework of 2D materials, we present four theoretical models of a vertical field-effect transistor (FET) composed of simple alternate graphene and MoS2 layers. The electronic transport properties at a specific graphene/MoS2 interface in each configuration are investigated by focusing in particular on the current as a function of the gate voltage. The gate voltage, simulated with a shift of the bands of a specific layer, allows us to tune the current at the interface and the charge transfer between the planes. This analysis of the charge transfer as a function of the gate voltage reveals a strong connection with the transport characteristics as the slope of the current curve. The analysis of physical phenomena at the graphene/MoS2 interface can further improve the 2D vertical FET performance and contribute to the development of new 2D nanotechnology.
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Affiliation(s)
- D Di Felice
- Service de Physique de l'Etat Condensé, DSM/IRAMIS/SPEC, CNRS UMR 3680, CEA Saclay, Université Paris-Saclay, F-91191 Gif-Sur-Yvette, France
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30
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Pijeat J, Dappe YJ, Thuéry P, Campidelli S. Synthesis and Suzuki-Miyaura cross coupling reactions for post-synthetic modification of a tetrabromo-anthracenyl porphyrin. Org Biomol Chem 2018; 16:8106-8114. [PMID: 30328882 DOI: 10.1039/c8ob02150c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The outstanding properties of porphyrins and the extreme versatility of their synthesis and their functionalisation constitute real assets for the fabrication of opto- and electroactive materials or for biological applications. In the large collection of porphyrinic structures, meso-substituted anthracenylporphyrins are among the less studied. Here, we synthesised the 5,10,15,20-tetra-bromoanthracenylporphyrin (BrTAP) and we investigated its chemical reactivity by post-synthetic modification using Suzuki-Miyaura cross coupling reactions with a series of boronic acids to generate a collection of original tetra-anthracenyl porphyrin based molecules: tetraphenylanthracenylporphyrin (TPAP), tetratolylanthracenylporphyrin (TTAP), tetramethoxyphenylanthracenylporphyrin (TMPAP), tetranaphthylanthracenylporphyrin (TNAP) and tetrapyrenylanthracenylporphyrin (TPyAP). Optical characterisations of these modified porphyrins showed, in most cases, only emission of the porphyrin in the visible region with extinction of the fluorescence of PAHs in the UV or visible region.
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Affiliation(s)
- Joffrey Pijeat
- LICSEN, NIMBE, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France.
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31
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Dubey S, Lisi S, Nayak G, Herziger F, Nguyen VD, Le Quang T, Cherkez V, González C, Dappe YJ, Watanabe K, Taniguchi T, Magaud L, Mallet P, Veuillen JY, Arenal R, Marty L, Renard J, Bendiab N, Coraux J, Bouchiat V. Correction to Weakly Trapped, Charged, and Free Excitons in Single-Layer MoS 2 in the Presence of Defects, Strain, and Charged Impurities. ACS Nano 2018; 12:10565-10566. [PMID: 30234967 DOI: 10.1021/acsnano.8b07086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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32
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Zhang Q, Liu C, Tao S, Yi R, Su W, Zhao C, Zhao C, Dappe YJ, Nichols RJ, Yang L. Fast and straightforward analysis approach of charge transport data in single molecule junctions. Nanotechnology 2018; 29:325701. [PMID: 29757161 DOI: 10.1088/1361-6528/aac45a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this study, we introduce an efficient data sorting algorithm, including filters for noisy signals, conductance mapping for analyzing the most dominant conductance group and sub-population groups. The capacity of our data analysis process has also been corroborated on real experimental data sets of Au-1,6-hexanedithiol-Au and Au-1,8-octanedithiol-Au molecular junctions. The fully automated and unsupervised program requires less than one minute on a standard PC to sort the data and generate histograms. The resulting one-dimensional and two-dimensional log histograms give conductance values in good agreement with previous studies. Our algorithm is a straightforward, fast and user-friendly tool for single molecule charge transport data analysis. We also analyze the data in a form of a conductance map which can offer evidence for diversity in molecular conductance. The code for automatic data analysis is openly available, well-documented and ready to use, thereby offering a useful new tool for single molecule electronics.
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Affiliation(s)
- Qian Zhang
- Department of Chemistry, Xi'an-Jiaotong Liverpool University, Suzhou, 215123, People's Republic of China. Department of Chemistry, University of Liverpool, Liverpool, L69 7ZD, United Kingdom
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33
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Dau MT, Gay M, Di Felice D, Vergnaud C, Marty A, Beigné C, Renaud G, Renault O, Mallet P, Le Quang T, Veuillen JY, Huder L, Renard VT, Chapelier C, Zamborlini G, Jugovac M, Feyer V, Dappe YJ, Pochet P, Jamet M. Beyond van der Waals Interaction: The Case of MoSe 2 Epitaxially Grown on Few-Layer Graphene. ACS Nano 2018; 12:2319-2331. [PMID: 29384649 DOI: 10.1021/acsnano.7b07446] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Van der Waals heterojunctions composed of graphene and transition metal dichalcogenides have gain much attention because of the possibility to control and tailor band structure, promising applications in two-dimensional optoelectronics and electronics. In this report, we characterized the van der Waals heterojunction MoSe2/few-layer graphene with a high-quality interface using cutting-edge surface techniques scaling from atomic to microscopic range. These surface analyses gave us a complete picture of the atomic structure and electronic properties of the heterojunction. In particular, we found two important results: the commensurability between the MoSe2 and few-layer graphene lattices and a band-gap opening in the few-layer graphene. The band gap is as large as 250 meV, and we ascribed it to an interface charge transfer that results in an electronic depletion in the few-layer graphene. This conclusion is well supported by electron spectroscopy data and density functional theory calculations. The commensurability between the MoSe2 and graphene lattices as well as the band-gap opening clearly show that the interlayer interaction goes beyond the simple van der Waals interaction. Hence, stacking two-dimensional materials in van der Waals heterojunctions enables us to tailor the atomic and electronic properties of individual layers. It also permits the introduction of a band gap in few-layer graphene by interface charge transfer.
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Affiliation(s)
- Minh Tuan Dau
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, INAC-SPINTEC, 38000 Grenoble , France
| | - Maxime Gay
- Université Grenoble Alpes , CEA, LETI, Minatec Campus, F-38054 Grenoble , France
| | - Daniela Di Felice
- SPEC, CEA, CNRS, Université Paris Saclay , CEA Saclay, 91191 Gif-sur-Yvette Cedex , France
| | - Céline Vergnaud
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, INAC-SPINTEC, 38000 Grenoble , France
| | - Alain Marty
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, INAC-SPINTEC, 38000 Grenoble , France
| | - Cyrille Beigné
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, INAC-SPINTEC, 38000 Grenoble , France
| | - Gilles Renaud
- Université Grenoble Alpes , CEA, INAC, MEM, 38000 Grenoble , France
| | - Olivier Renault
- Université Grenoble Alpes , CEA, LETI, Minatec Campus, F-38054 Grenoble , France
| | - Pierre Mallet
- Université Grenoble Alpes, CNRS, Institut Néel , F-38000 Grenoble , France
| | - Toai Le Quang
- Université Grenoble Alpes, CNRS, Institut Néel , F-38000 Grenoble , France
| | - Jean-Yves Veuillen
- Université Grenoble Alpes, CNRS, Institut Néel , F-38000 Grenoble , France
| | - Loïc Huder
- Université Grenoble Alpes , CEA, INAC, PHELIQS, 38000 Grenoble , France
| | - Vincent T Renard
- Université Grenoble Alpes , CEA, INAC, PHELIQS, 38000 Grenoble , France
| | - Claude Chapelier
- Université Grenoble Alpes , CEA, INAC, PHELIQS, 38000 Grenoble , France
| | - Giovanni Zamborlini
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH , D-52425 , Jülich , Germany
| | - Matteo Jugovac
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH , D-52425 , Jülich , Germany
| | - Vitaliy Feyer
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH , D-52425 , Jülich , Germany
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris Saclay , CEA Saclay, 91191 Gif-sur-Yvette Cedex , France
| | - Pascal Pochet
- Université Grenoble Alpes , CEA, INAC, MEM, 38000 Grenoble , France
| | - Matthieu Jamet
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, INAC-SPINTEC, 38000 Grenoble , France
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He C, Zhang Q, Tao S, Zhao C, Zhao C, Su W, Dappe YJ, Nichols RJ, Yang L. Carbon-contacted single molecule electrical junctions. Phys Chem Chem Phys 2018; 20:24553-24560. [DOI: 10.1039/c8cp02877j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A fully metal-free molecular junction by using carbon fiber as the top electrode, and graphene as the bottom electrode was demonstrated for single molecular junctions, which is retaining long-lived charge excited states and potential for charge storage and manipulation.
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Affiliation(s)
- Chunhui He
- Department of Chemistry
- Xi’an-Jiaotong Liverpool University
- Suzhou
- China
- Department of Chemistry
| | - Qian Zhang
- Department of Chemistry
- Xi’an-Jiaotong Liverpool University
- Suzhou
- China
- Department of Chemistry
| | - Shuhui Tao
- Department of Chemistry
- Xi’an-Jiaotong Liverpool University
- Suzhou
- China
- Department of Chemistry
| | - Cezhou Zhao
- Department of Electrical and Electronic Engineering
- Xi’an-Jiaotong Liverpool University
- Suzhou
- China
| | - Chun Zhao
- Department of Electrical and Electronic Engineering
- Xi’an-Jiaotong Liverpool University
- Suzhou
- China
| | - Weitao Su
- College of Materials and Environmental Engineering
- Hangzhou Dianzi University
- Hangzhou
- China
| | | | | | - Li Yang
- Department of Chemistry
- Xi’an-Jiaotong Liverpool University
- Suzhou
- China
- Department of Chemistry
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35
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Zhang Q, Tao S, Yi R, He C, Zhao C, Su W, Smogunov A, Dappe YJ, Nichols RJ, Yang L. Symmetry Effects on Attenuation Factors in Graphene-Based Molecular Junctions. J Phys Chem Lett 2017; 8:5987-5992. [PMID: 29178793 DOI: 10.1021/acs.jpclett.7b02822] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The unique structural and electronic characteristics of graphene make it an attractive contact for fundamental single-molecule electrical studies. With this in mind, we have probed here the electrical conductance of a molecular junction based on α,ω-diaminoalkane chains sandwiched between a gold and a graphene electrode. Using an STM based I(s) method combined with density functional theory-based transport calculations, we demonstrate that the resulting attenuation factor turns out to be much lower when compared to the standard molecular junction between two gold electrodes. This effect is attributed to asymmetric coupling of the molecule through strong chemisorption at the gold electrode and weaker van der Waals contact at graphene. Moreover, this asymmetric coupling induces higher conductance than that in the same hybrid metal-graphene molecular junction using standard thiol anchoring groups.
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Affiliation(s)
- Qian Zhang
- Department of Chemistry, Xi'an-Jiaotong Liverpool University , 215123 Suzhou, China
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Shuhui Tao
- Department of Chemistry, Xi'an-Jiaotong Liverpool University , 215123 Suzhou, China
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Ruowei Yi
- Department of Chemistry, Xi'an-Jiaotong Liverpool University , 215123 Suzhou, China
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Chunhui He
- Department of Chemistry, Xi'an-Jiaotong Liverpool University , 215123 Suzhou, China
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Cezhou Zhao
- Department of Electrical and Electronic Engineering, Xi'an-Jiaotong Liverpool University , 215123 Suzhou, China
| | - Weitao Su
- College of Materials and Environmental Engineering, Hangzhou Dianzi University , 310018 Hangzhou, China
| | - Alexander Smogunov
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette, Cedex, France
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette, Cedex, France
| | - Richard J Nichols
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
| | - Li Yang
- Department of Chemistry, Xi'an-Jiaotong Liverpool University , 215123 Suzhou, China
- Department of Chemistry, University of Liverpool , Liverpool L69 7ZD, United Kingdom
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Pham VD, Repain V, Chacon C, Bellec A, Girard Y, Rousset S, Abad E, Dappe YJ, Smogunov A, Lagoute J. Tuning the Electronic and Dynamical Properties of a Molecule by Atom Trapping Chemistry. ACS Nano 2017; 11:10742-10749. [PMID: 28960959 DOI: 10.1021/acsnano.7b05235] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The ability to trap adatoms with an organic molecule on a surface has been used to obtain a range of molecular functionalities controlled by the choice of the molecular trapping site and local deprotonation. The tetraphenylporphyrin molecule used in this study contains three types of trapping sites: two carbon rings (phenyl and pyrrole) and the center of a macrocycle. Catching a gold adatom on the carbon rings leads to an electronic doping of the molecule, whereas trapping the adatom at the macrocycle center with single deprotonation leads to a molecular rotor and a second deprotonation leads to a molecular jumper. We call "atom trapping chemistry" the control of the structure, electronic, and dynamical properties of a molecule achieved by trapping metallic atoms with a molecule on a surface. In addition to the examples previously described, we show that more complex structures can be envisaged.
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Affiliation(s)
- Van Dong Pham
- Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot , Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France
| | - Vincent Repain
- Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot , Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France
| | - Cyril Chacon
- Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot , Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France
| | - Amandine Bellec
- Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot , Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France
| | - Yann Girard
- Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot , Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France
| | - Sylvie Rousset
- Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot , Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France
| | - Enrique Abad
- Departamento Física Teórica de la Materia Condensada, Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid , E-28049 Madrid, Spain
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay , CEA Saclay, 91191 Cedex Gif-sur-Yvette, France
| | - Alexander Smogunov
- SPEC, CEA, CNRS, Université Paris-Saclay , CEA Saclay, 91191 Cedex Gif-sur-Yvette, France
| | - Jérôme Lagoute
- Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot , Sorbonne Paris Cité, CNRS, UMR 7162, 75013 Paris, France
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Dubey S, Lisi S, Nayak G, Herziger F, Nguyen VD, Le Quang T, Cherkez V, González C, Dappe YJ, Watanabe K, Taniguchi T, Magaud L, Mallet P, Veuillen JY, Arenal R, Marty L, Renard J, Bendiab N, Coraux J, Bouchiat V. Weakly Trapped, Charged, and Free Excitons in Single-Layer MoS 2 in the Presence of Defects, Strain, and Charged Impurities. ACS Nano 2017; 11:11206-11216. [PMID: 28992415 DOI: 10.1021/acsnano.7b05520] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Few- and single-layer MoS2 host substantial densities of defects. They are thought to influence the doping level, the crystal structure, and the binding of electron-hole pairs. We disentangle the concomitant spectroscopic expression of all three effects and identify to what extent they are intrinsic to the material or extrinsic to it, i.e., related to its local environment. We do so by using different sources of MoS2-a natural one and one prepared at high pressure and high temperature-and different substrates bringing varying amounts of charged impurities and by separating the contributions of internal strain and doping in Raman spectra. Photoluminescence unveils various optically active excitonic complexes. We discover a defect-bound state having a low binding energy of 20 meV that does not appear sensitive to strain and doping, unlike charged excitons. Conversely, the defect does not significantly dope or strain MoS2. Scanning tunneling microscopy and density functional theory simulations point to substitutional atoms, presumably individual nitrogen atoms at the sulfur site. Our work shows the way to a systematic understanding of the effect of external and internal fields on the optical properties of two-dimensional materials.
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Affiliation(s)
- Sudipta Dubey
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Simone Lisi
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Goutham Nayak
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Felix Herziger
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Van-Dung Nguyen
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Toai Le Quang
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Vladimir Cherkez
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - César González
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex, France
- Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Facultad de Ciencias, Universidad Autonoma de Madrid , E-28049 Madrid, Spain
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex, France
| | - Kenji Watanabe
- National Institute for Materials Science , Tsukuba, 305-0044, Japan
| | | | - Laurence Magaud
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Pierre Mallet
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Jean-Yves Veuillen
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Raul Arenal
- Laboratorio de Microscopiías Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza , 50018 Zaragoza, Spain
- ARAID Foundation , 50018 Zaragoza, Spain
| | - Laëtitia Marty
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Julien Renard
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Nedjma Bendiab
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Johann Coraux
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Vincent Bouchiat
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
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Pierucci D, Henck H, Ben Aziza Z, Naylor CH, Balan A, Rault JE, Silly MG, Dappe YJ, Bertran F, Le Fèvre P, Sirotti F, Johnson ATC, Ouerghi A. Tunable Doping in Hydrogenated Single Layered Molybdenum Disulfide. ACS Nano 2017; 11:1755-1761. [PMID: 28146631 DOI: 10.1021/acsnano.6b07661] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Structural defects in the molybdenum disulfide (MoS2) monolayer are widely known for strongly altering its properties. Therefore, a deep understanding of these structural defects and how they affect MoS2 electronic properties is of fundamental importance. Here, we report on the incorporation of atomic hydrogen in monolayered MoS2 to tune its structural defects. We demonstrate that the electronic properties of single layer MoS2 can be tuned from the intrinsic electron (n) to hole (p) doping via controlled exposure to atomic hydrogen at room temperature. Moreover, this hydrogenation process represents a viable technique to completely saturate the sulfur vacancies present in the MoS2 flakes. The successful incorporation of hydrogen in MoS2 leads to the modification of the electronic properties as evidenced by high resolution X-ray photoemission spectroscopy and density functional theory calculations. Micro-Raman spectroscopy and angle resolved photoemission spectroscopy measurements show the high quality of the hydrogenated MoS2 confirming the efficiency of our hydrogenation process. These results demonstrate that the MoS2 hydrogenation could be a significant and efficient way to achieve tunable doping of transition metal dichalcogenides (TMD) materials with non-TMD elements.
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Affiliation(s)
- Debora Pierucci
- Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay , C2N - Marcoussis, F91460 Marcoussis, France
| | - Hugo Henck
- Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay , C2N - Marcoussis, F91460 Marcoussis, France
| | - Zeineb Ben Aziza
- Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay , C2N - Marcoussis, F91460 Marcoussis, France
| | - Carl H Naylor
- Department of Physics and Astronomy, University of Pennsylvania , 209S 33rd Street, Philadelphia, Pennsylvania 19104, United States
| | - Adrian Balan
- Department of Physics and Astronomy, University of Pennsylvania , 209S 33rd Street, Philadelphia, Pennsylvania 19104, United States
| | - Julien E Rault
- Synchrotron-SOLEIL , Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - Mathieu G Silly
- Synchrotron-SOLEIL , Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay , CEA Saclay, F91191 Gif-sur-Yvette Cedex, France
| | - François Bertran
- Synchrotron-SOLEIL , Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - Patrick Le Fèvre
- Synchrotron-SOLEIL , Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - Fausto Sirotti
- Synchrotron-SOLEIL , Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - A T Charlie Johnson
- Department of Physics and Astronomy, University of Pennsylvania , 209S 33rd Street, Philadelphia, Pennsylvania 19104, United States
| | - Abdelkarim Ouerghi
- Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay , C2N - Marcoussis, F91460 Marcoussis, France
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Abstract
Different molecules physisorbed, chemisorbed or dissociated on a defective MoS2layer.
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Affiliation(s)
- César González
- Departamento de Electrónica y Tecnología de Computadores
- Campus de Fuente Nueva & CITIC
- Universidad de Granada
- E-18071 Granada
- Spain
| | - Blanca Biel
- Departamento de Electrónica y Tecnología de Computadores
- Campus de Fuente Nueva & CITIC
- Universidad de Granada
- E-18071 Granada
- Spain
| | - Yannick J. Dappe
- SPEC
- CEA
- CNRS
- Université Paris-Saclay
- CEA Saclay 91191 Gif-sur-Yvette Cedex
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40
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Campbell VE, Tonelli M, Cimatti I, Moussy JB, Tortech L, Dappe YJ, Rivière E, Guillot R, Delprat S, Mattana R, Seneor P, Ohresser P, Choueikani F, Otero E, Koprowiak F, Chilkuri VG, Suaud N, Guihéry N, Galtayries A, Miserque F, Arrio MA, Sainctavit P, Mallah T. Engineering the magnetic coupling and anisotropy at the molecule-magnetic surface interface in molecular spintronic devices. Nat Commun 2016; 7:13646. [PMID: 27929089 PMCID: PMC5476799 DOI: 10.1038/ncomms13646] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 10/14/2016] [Indexed: 11/26/2022] Open
Abstract
A challenge in molecular spintronics is to control the magnetic coupling between magnetic molecules and magnetic electrodes to build efficient devices. Here we show that the nature of the magnetic ion of anchored metal complexes highly impacts the exchange coupling of the molecules with magnetic substrates. Surface anchoring alters the magnetic anisotropy of the cobalt(II)-containing complex (Co(Pyipa)2), and results in blocking of its magnetization due to the presence of a magnetic hysteresis loop. In contrast, no hysteresis loop is observed in the isostructural nickel(II)-containing complex (Ni(Pyipa)2). Through XMCD experiments and theoretical calculations we find that Co(Pyipa)2 is strongly ferromagnetically coupled to the surface, while Ni(Pyipa)2 is either not coupled or weakly antiferromagnetically coupled to the substrate. These results highlight the importance of the synergistic effect that the electronic structure of a metal ion and the organic ligands has on the exchange interaction and anisotropy occurring at the molecule–electrode interface.
Controlling the magnetic response of a molecular device is important for spintronic applications. Here the authors report the self-assembly, magnetic coupling, and anisotropy of two transition metal complexes bound to a ferrimagnetic surface, and probe the role of the nature of the transition metal ion.
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Affiliation(s)
- Victoria E Campbell
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), CNRS, Université Paris Sud, Université Paris Saclay, 91405 Orsay, France
| | - Monica Tonelli
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), CNRS, Université Paris Sud, Université Paris Saclay, 91405 Orsay, France
| | - Irene Cimatti
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), CNRS, Université Paris Sud, Université Paris Saclay, 91405 Orsay, France
| | - Jean-Baptiste Moussy
- SPEC, CEA, CNRS, Univesité Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Ludovic Tortech
- IPCM, UMR CNRS 7201, UPMC, Université Pierre et Marie Curie, F-75005 Paris, France
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Univesité Paris Saclay, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Eric Rivière
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), CNRS, Université Paris Sud, Université Paris Saclay, 91405 Orsay, France
| | - Régis Guillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), CNRS, Université Paris Sud, Université Paris Saclay, 91405 Orsay, France
| | - Sophie Delprat
- Unité Mixte de Physique CNRS/Thales, 1 Avenue Auguste Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - Richard Mattana
- Unité Mixte de Physique CNRS/Thales, 1 Avenue Auguste Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - Pierre Seneor
- Unité Mixte de Physique CNRS/Thales, 1 Avenue Auguste Fresnel, 91767 Palaiseau, France and Université Paris-Sud, 91405 Orsay, France
| | - Philippe Ohresser
- Synchrotron SOLEIL, L'Orme des Merisiers Saint-Aubin-BP 48, 91192 Gif-sur-Yvette, France
| | - Fadi Choueikani
- Synchrotron SOLEIL, L'Orme des Merisiers Saint-Aubin-BP 48, 91192 Gif-sur-Yvette, France
| | - Edwige Otero
- Synchrotron SOLEIL, L'Orme des Merisiers Saint-Aubin-BP 48, 91192 Gif-sur-Yvette, France
| | - Florian Koprowiak
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse III, 118, route de Narbonne, 31062 Toulouse, France
| | - Vijay Gopal Chilkuri
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse III, 118, route de Narbonne, 31062 Toulouse, France
| | - Nicolas Suaud
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse III, 118, route de Narbonne, 31062 Toulouse, France
| | - Nathalie Guihéry
- Laboratoire de Chimie et Physique Quantiques, Université de Toulouse III, 118, route de Narbonne, 31062 Toulouse, France
| | - Anouk Galtayries
- PSL Research University, Chimie ParisTech-CNRS, Institut de Recherche de Chimie Paris, F-75005 Paris, France
| | - Frederic Miserque
- CEA/DEN/DANS/DPC/SCCME, Laboratoire d'Etude de la Corrosion Aqueuse, F-91191 Gif-sur-Yvette, France
| | - Marie-Anne Arrio
- IMPMC-CNRS, Université Pierre et Marie Curie, F-75005 Paris, France
| | - Philippe Sainctavit
- Synchrotron SOLEIL, L'Orme des Merisiers Saint-Aubin-BP 48, 91192 Gif-sur-Yvette, France.,IMPMC-CNRS, Université Pierre et Marie Curie, F-75005 Paris, France
| | - Talal Mallah
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), CNRS, Université Paris Sud, Université Paris Saclay, 91405 Orsay, France
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Zhang Q, Liu L, Tao S, Wang C, Zhao C, González C, Dappe YJ, Nichols RJ, Yang L. Graphene as a Promising Electrode for Low-Current Attenuation in Nonsymmetric Molecular Junctions. Nano Lett 2016; 16:6534-6540. [PMID: 27668518 DOI: 10.1021/acs.nanolett.6b03180] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We have measured the single-molecule conductance of 1,n-alkanedithiol molecular bridges (n = 4, 6, 8, 10, 12) on a graphene substrate using scanning tunneling microscopy (STM)-formed electrical junctions. The conductance values of this homologous series ranged from 2.3 nS (n = 12) to 53 nS (n = 4), with a decay constant βn of 0.40 per methylene (-CH2) group. This result is explained by a combination of density functional theory (DFT) and Keldysh-Green function calculations. The obtained decay, which is much lower than the one obtained for symmetric gold junctions, is related to the weak coupling at the molecule-graphene interface and the electronic structure of graphene. As a consequence, we show that using graphene nonsymmetric junctions and appropriate anchoring groups may lead to a much-lower decay constant and more-conductive molecular junctions at longer lengths.
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Affiliation(s)
- Qian Zhang
- Department of Chemistry, University of Liverpool , Liverpool, L69 7ZD U.K
| | - Longlong Liu
- Department of Chemistry and Chemical Engineering, Chongqing University , Chongqing, 400030, China
| | - Shuhui Tao
- Department of Chemistry, University of Liverpool , Liverpool, L69 7ZD U.K
| | | | | | - César González
- SPEC, CEA, CNRS, Université Paris-Saclay , CEA Saclay 91191 Gif-sur-Yvette Cedex, France
- Departamento de Electrónica y Tecnología de Computadores, Universidad de Granada , Campus de Fuente Nueva & CITIC, Campus de Aynadamar 18071, Granada, Spain
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay , CEA Saclay 91191 Gif-sur-Yvette Cedex, France
| | - Richard J Nichols
- Department of Chemistry, University of Liverpool , Liverpool, L69 7ZD U.K
| | - Li Yang
- Department of Chemistry, University of Liverpool , Liverpool, L69 7ZD U.K
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Pierucci D, Henck H, Avila J, Balan A, Naylor CH, Patriarche G, Dappe YJ, Silly MG, Sirotti F, Johnson ATC, Asensio MC, Ouerghi A. Band Alignment and Minigaps in Monolayer MoS2-Graphene van der Waals Heterostructures. Nano Lett 2016; 16:4054-4061. [PMID: 27281693 DOI: 10.1021/acs.nanolett.6b00609] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Two-dimensional layered MoS2 shows great potential for nanoelectronic and optoelectronic devices due to its high photosensitivity, which is the result of its indirect to direct band gap transition when the bulk dimension is reduced to a single monolayer. Here, we present an exhaustive study of the band alignment and relativistic properties of a van der Waals heterostructure formed between single layers of MoS2 and graphene. A sharp, high-quality MoS2-graphene interface was obtained and characterized by micro-Raman spectroscopy, high-resolution X-ray photoemission spectroscopy (HRXPS), and scanning high-resolution transmission electron microscopy (STEM/HRTEM). Moreover, direct band structure determination of the MoS2/graphene van der Waals heterostructure monolayer was carried out using angle-resolved photoemission spectroscopy (ARPES), shedding light on essential features such as doping, Fermi velocity, hybridization, and band-offset of the low energy electronic dynamics found at the interface. We show that, close to the Fermi level, graphene exhibits a robust, almost perfect, gapless, and n-doped Dirac cone and no significant charge transfer doping is detected from MoS2 to graphene. However, modification of the graphene band structure occurs at rather larger binding energies, as the opening of several miniband-gaps is observed. These miniband-gaps resulting from the overlay of MoS2 and the graphene layer lattice impose a superperiodic potential.
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Affiliation(s)
- Debora Pierucci
- Centre de Nanosciences et de Nanotechnologies, CNRS Univ. Paris-Sud, Université Paris-Saclay , C2N - Marcoussis, 91460 Marcoussis, France
| | - Hugo Henck
- Centre de Nanosciences et de Nanotechnologies, CNRS Univ. Paris-Sud, Université Paris-Saclay , C2N - Marcoussis, 91460 Marcoussis, France
| | - Jose Avila
- Synchrotron-SOLEIL , Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - Adrian Balan
- Department of Physics and Astronomy, University of Pennsylvania , 209S 33rd Street, Philadelphia, Pennsylvania 19104 6396, United States
- LICSEN, NIMBE, CEA, CNRS, Université Paris Saclay , CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Carl H Naylor
- Department of Physics and Astronomy, University of Pennsylvania , 209S 33rd Street, Philadelphia, Pennsylvania 19104 6396, United States
| | - Gilles Patriarche
- Centre de Nanosciences et de Nanotechnologies, CNRS Univ. Paris-Sud, Université Paris-Saclay , C2N - Marcoussis, 91460 Marcoussis, France
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris Saclay , CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Mathieu G Silly
- Synchrotron-SOLEIL , Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - Fausto Sirotti
- Synchrotron-SOLEIL , Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - A T Charlie Johnson
- Department of Physics and Astronomy, University of Pennsylvania , 209S 33rd Street, Philadelphia, Pennsylvania 19104 6396, United States
| | - Maria C Asensio
- Synchrotron-SOLEIL , Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - Abdelkarim Ouerghi
- Centre de Nanosciences et de Nanotechnologies, CNRS Univ. Paris-Sud, Université Paris-Saclay , C2N - Marcoussis, 91460 Marcoussis, France
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Pierucci D, Henck H, Naylor CH, Sediri H, Lhuillier E, Balan A, Rault JE, Dappe YJ, Bertran F, Fèvre PL, Johnson ATC, Ouerghi A. Large area molybdenum disulphide- epitaxial graphene vertical Van der Waals heterostructures. Sci Rep 2016; 6:26656. [PMID: 27246929 PMCID: PMC4894673 DOI: 10.1038/srep26656] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 05/03/2016] [Indexed: 11/09/2022] Open
Abstract
Two-dimensional layered transition metal dichalcogenides (TMDCs) show great potential for optoelectronic devices due to their electronic and optical properties. A metal-semiconductor interface, as epitaxial graphene - molybdenum disulfide (MoS2), is of great interest from the standpoint of fundamental science, as it constitutes an outstanding platform to investigate the interlayer interaction in van der Waals heterostructures. Here, we study large area MoS2-graphene-heterostructures formed by direct transfer of chemical-vapor deposited MoS2 layer onto epitaxial graphene/SiC. We show that via a direct transfer, which minimizes interface contamination, we can obtain high quality and homogeneous van der Waals heterostructures. Angle-resolved photoemission spectroscopy (ARPES) measurements combined with Density Functional Theory (DFT) calculations show that the transition from indirect to direct bandgap in monolayer MoS2 is maintained in these heterostructures due to the weak van der Waals interaction with epitaxial graphene. A downshift of the Raman 2D band of the graphene, an up shift of the A1g peak of MoS2 and a significant photoluminescence quenching are observed for both monolayer and bilayer MoS2 as a result of charge transfer from MoS2 to epitaxial graphene under illumination. Our work provides a possible route to modify the thin film TDMCs photoluminescence properties via substrate engineering for future device design.
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Affiliation(s)
- Debora Pierucci
- Laboratoire de Photonique et de Nanostructures (CNRS- LPN),
Route de Nozay, 91460
Marcoussis, France
| | - Hugo Henck
- Laboratoire de Photonique et de Nanostructures (CNRS- LPN),
Route de Nozay, 91460
Marcoussis, France
| | - Carl H. Naylor
- Department of Physics and Astronomy, University of
Pennsylvania, 209S 33rd Street, Philadelphia,
Pennsylvania
19104, USA
| | - Haikel Sediri
- Laboratoire de Photonique et de Nanostructures (CNRS- LPN),
Route de Nozay, 91460
Marcoussis, France
| | - Emmanuel Lhuillier
- Institut des Nanosciences de Paris, UPMC, 4 place Jussieu,
boîte courrier 840, 75252
Paris cedex 05, France
| | - Adrian Balan
- Department of Physics and Astronomy, University of
Pennsylvania, 209S 33rd Street, Philadelphia,
Pennsylvania
19104, USA
- Laboratoire d’Innovation en Chimie des Surfaces et
Nanosciences, DSM/NIMBE/LICSEN (CNRS UMR 3685), CEA Saclay,
91191
Gif-sur-Yvette Cedex, France
| | - Julien E. Rault
- Synchrotron-SOLEIL, Saint-Aubin, BP48,
F91192 Gif sur Yvette Cedex, France
| | - Yannick J. Dappe
- SPEC, CEA, CNRS, Universite Paris-Saclay, CEA Saclay,
91191 Gif-sur-Yvette Cedex, France
| | - François Bertran
- Synchrotron-SOLEIL, Saint-Aubin, BP48,
F91192 Gif sur Yvette Cedex, France
| | - Patrick Le Fèvre
- Synchrotron-SOLEIL, Saint-Aubin, BP48,
F91192 Gif sur Yvette Cedex, France
| | - A. T. Charlie Johnson
- Department of Physics and Astronomy, University of
Pennsylvania, 209S 33rd Street, Philadelphia,
Pennsylvania
19104, USA
| | - Abdelkarim Ouerghi
- Laboratoire de Photonique et de Nanostructures (CNRS- LPN),
Route de Nozay, 91460
Marcoussis, France
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Pham VD, Repain V, Chacon C, Bellec A, Girard Y, Rousset S, Smogunov A, Dappe YJ, Lagoute J. Control of Molecule-Metal Interaction by Hydrogen Manipulation in an Organic Molecule. J Phys Chem Lett 2016; 7:1416-1421. [PMID: 27028149 DOI: 10.1021/acs.jpclett.6b00476] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Free-base porphyrin molecules offer appealing options to tune the interaction with their environment via the manipulation of their inner hydrogen atoms and molecular conformation. Using scanning tunneling microscopy we show, through a systematic study, that the molecular conformation, electronic gap, wave function, and molecule-substrate interaction are modified by hydrogen switch or removal. Experimental results in combination with ab initio calculations provide an understanding of the underlying physical process.
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Affiliation(s)
- Van Dong Pham
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS-Université Paris 7 , 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
| | - Vincent Repain
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS-Université Paris 7 , 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
| | - Cyril Chacon
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS-Université Paris 7 , 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
| | - Amandine Bellec
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS-Université Paris 7 , 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
| | - Yann Girard
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS-Université Paris 7 , 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
| | - Sylvie Rousset
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS-Université Paris 7 , 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
| | - Alexander Smogunov
- SPEC, CEA, CNRS, Université Paris-Saclay , CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay , CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Jérôme Lagoute
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS-Université Paris 7 , 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
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45
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González C, Biel B, Dappe YJ. Theoretical characterisation of point defects on a MoS2 monolayer by scanning tunnelling microscopy. Nanotechnology 2016; 27:105702. [PMID: 26862020 DOI: 10.1088/0957-4484/27/10/105702] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Different S and Mo vacancies as well as their corresponding antisite defects in a free-standing MoS2 monolayer are analysed by means of scanning tunnelling microscopy (STM) simulations. Our theoretical methodology, based on the Keldysh nonequilibrium Green function formalism within the density functional theory (DFT) approach, is applied to simulate STM images for different voltages and tip heights. Combining the geometrical and electronic effects, all features of the different STM images can be explained, providing a valuable guide for future experiments. Our results confirm previous reports on S atom imaging, but also reveal a strong dependence on the applied bias for vacancies and antisite defects that include extra S atoms. By contrast, when additional Mo atoms cover the S vacancies, the MoS2 gap vanishes and a bias-independent bright protrusion is obtained in the STM image. Finally, we show that the inclusion of these point defects promotes the emergence of reactive dangling bonds that may act as efficient adsorption sites for external adsorbates.
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Affiliation(s)
- C González
- Departamento de Electrónica y Tecnología de Computadores, Universidad de Granada, Campus de Fuente Nueva & CITIC, Campus de Aynadamar E-18071 Granada, Spain. SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex, France
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46
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Abstract
Motivated by recent experiments, we present here a detailed theoretical analysis of the use of carbon-based conductive tips in scanning tunnelling microscopy. In particular, we employ ab initio methods based on density functional theory to explore a graphitic, an amorphous carbon and two diamond-like tips for imaging with a scanning tunnelling microscope (STM), and we compare them with standard metallic tips made of gold and tungsten. We investigate the performance of these tips in terms of the corrugation of the STM images acquired when scanning a single graphene sheet. Moreover, we analyse the impact of the tip-sample distance and show that it plays a fundamental role in the resolution and symmetry of the STM images. We also explore in depth how the adsorption of single atoms and molecules in the tip apexes modifies the STM images and demonstrate that, in general, it leads to an improved image resolution. The ensemble of our results provides strong evidence that carbon-based tips can significantly improve the resolution of STM images, as compared to more standard metallic tips, which may open a new line of research in scanning tunnelling microscopy.
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Affiliation(s)
- C González
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette Cedex, France. Departamento de electrónica y Tecnología de Computadores, Universidad de Granada, Fuente Nueva & CITIC, Aynadamar E-18071 Granada, Spain
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47
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Sediri H, Pierucci D, Hajlaoui M, Henck H, Patriarche G, Dappe YJ, Yuan S, Toury B, Belkhou R, Silly MG, Sirotti F, Boutchich M, Ouerghi A. Atomically Sharp Interface in an h-BN-epitaxial graphene van der Waals Heterostructure. Sci Rep 2015; 5:16465. [PMID: 26585245 PMCID: PMC4653732 DOI: 10.1038/srep16465] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 10/05/2015] [Indexed: 11/24/2022] Open
Abstract
Stacking various two-dimensional atomic crystals is a feasible approach to creating unique multilayered van der Waals heterostructures with tailored properties. Herein for the first time, we present a controlled preparation of large-area h-BN/graphene heterostructures via a simple chemical deposition of h-BN layers on epitaxial graphene/SiC(0001). Van der Waals forces, which are responsible for the cohesion of the multilayer system, give rise to an abrupt interface without interdiffusion between graphene and h-BN, as shown by X-ray Photoemission Spectroscopy (XPS) and direct observation using scanning and High-Resolution Transmission Electron Microscopy (STEM/HRTEM). The electronic properties of graphene, such as the Dirac cone, remain intact and no significant charge transfer i.e. doping, is observed. These results are supported by Density Functional Theory (DFT) calculations. We demonstrate that the h-BN capped graphene allows the fabrication of vdW heterostructures without altering the electronic properties of graphene.
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Affiliation(s)
- Haikel Sediri
- Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, route de Nozay, F-91460 Marcoussis, France
| | - Debora Pierucci
- Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, route de Nozay, F-91460 Marcoussis, France
| | - Mahdi Hajlaoui
- Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, route de Nozay, F-91460 Marcoussis, France.,Synchrotron-SOLEIL, Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - Hugo Henck
- Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, route de Nozay, F-91460 Marcoussis, France
| | - Gilles Patriarche
- Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, route de Nozay, F-91460 Marcoussis, France
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris Saclay, CEA Saclay, 91191, Gif-Sur-Yvette, France
| | - Sheng Yuan
- Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, Université Lyon I, Université de Lyon, France
| | - Bérangère Toury
- Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, Université Lyon I, Université de Lyon, France
| | - Rachid Belkhou
- Synchrotron-SOLEIL, Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - Mathieu G Silly
- Synchrotron-SOLEIL, Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - Fausto Sirotti
- Synchrotron-SOLEIL, Saint-Aubin, BP48, F91192 Gif sur Yvette Cedex, France
| | - Mohamed Boutchich
- GeePs, CNRS UMR8507, CentraleSupelec, Univ Paris-Sud, Sorbonne Universités-UPMC Univ Paris 06, 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette Cedex, France
| | - Abdelkarim Ouerghi
- Laboratoire de Photonique et de Nanostructures (LPN), CNRS, Université Paris-Saclay, route de Nozay, F-91460 Marcoussis, France
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48
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Günes F, Arezki H, Pierucci D, Alamarguy D, Alvarez J, Kleider JP, Dappe YJ, Ouerghi A, Boutchich M. Tuning the work function of monolayer graphene on 4H-SiC (0001) with nitric acid. Nanotechnology 2015; 26:445702. [PMID: 26457876 DOI: 10.1088/0957-4484/26/44/445702] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Chemical doping of graphene is a key process for the modulation of its electronic properties and the design and fabrication of graphene-based nanoelectronic devices. Here, we study the adsorption of diluted concentrations of nitric acid (HNO3) onto monolayer graphene/4H-SiC (0001) to induce a variation of the graphene work function (WF). Raman spectroscopy indicates an increase in the defect density subsequent to the doping. Moreover, ultraviolet photoemission spectroscopy (UPS) was utilized to quantify the WF shift. UPS data show that the WF of the graphene layer decreased from 4.3 eV (pristine) down to 3.8 eV (30% HNO3) and then increased to 4.4 eV at 100% HNO3 concentration. These observations were confirmed using density functional theory (DFT) calculations. This straightforward process allows a large WF modulation, rendering the molecularly modified graphene/4H-SiC(0001) a highly suitable electron or hole injection electrode.
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Affiliation(s)
- Fethullah Günes
- GeePs, CNRS UMR8507, CentraleSupelec, Univ Paris-Sud, Sorbonne Universités-UPMC Univ Paris 06, 11 rue Joliot-Curie, Plateau de Moulon, 91192 Gif-sur-Yvette Cedex, France. Department of Materials Science and Engineering, Izmir Kâtip Çelebi University Cigli Main Campus, 35620, IZMIR, Turkey
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49
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Reecht G, Bulou H, Scheurer F, Speisser V, Mathevet F, González C, Dappe YJ, Schull G. Pulling and Stretching a Molecular Wire to Tune its Conductance. J Phys Chem Lett 2015; 6:2987-2992. [PMID: 26267192 DOI: 10.1021/acs.jpclett.5b01283] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A scanning tunnelling microscope is used to pull a polythiophene wire from a Au(111) surface while measuring the current traversing the junction. Abrupt current increases measured during the lifting procedure are associated with the detachment of molecular subunits, in apparent contradiction with the expected exponential decrease of the conductance with wire length. Ab initio simulations reproduce the experimental data and demonstrate that this unexpected behavior is due to release of mechanical stress in the wire, paving the way to mechanically gated single-molecule electronic devices.
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Affiliation(s)
- Gaël Reecht
- †IPCMS de Strasbourg, UMR 7504 (CNRS - Université de Strasbourg), 67034 Strasbourg, France
| | - Hervé Bulou
- †IPCMS de Strasbourg, UMR 7504 (CNRS - Université de Strasbourg), 67034 Strasbourg, France
| | - Fabrice Scheurer
- †IPCMS de Strasbourg, UMR 7504 (CNRS - Université de Strasbourg), 67034 Strasbourg, France
| | - Virginie Speisser
- †IPCMS de Strasbourg, UMR 7504 (CNRS - Université de Strasbourg), 67034 Strasbourg, France
| | - Fabrice Mathevet
- ‡Institut Parisien de Chimie Moléculaire, Chimie des Polymères, UMR 8232, (CNRS - Université Pierre et Marie Curie), 75252 Paris, France
| | - César González
- §Service de Physique de l'Etat Condensé, DSM/IRAMIS/SPEC, CNRS UMR 3680, CEA Saclay, 91191 Gif sur Yvette cedex, France
| | - Yannick J Dappe
- §Service de Physique de l'Etat Condensé, DSM/IRAMIS/SPEC, CNRS UMR 3680, CEA Saclay, 91191 Gif sur Yvette cedex, France
| | - Guillaume Schull
- †IPCMS de Strasbourg, UMR 7504 (CNRS - Université de Strasbourg), 67034 Strasbourg, France
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50
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Abstract
Achieving highly spin-polarized electric currents in atomic-scale junctions is of great importance in the field of nanoelectronics and spintronics. Based on robust symmetry considerations, we propose a mechanism to block completely one of spin conduction channels for a broad class of atomic and molecular junctions bridging two ferromagnetic electrodes. This particular behavior is due to the wave function orthogonality between spin up s-like states in ferromagnetic electrode and available π channels in the junction. As a consequence, the system would ideally yield 100% spin-polarized current, with a junction acting thus as a "half-metallic" conductor. Using ab initio electron transport calculations, we demonstrate this principle on two examples: (i) a short carbon chain and (ii) a π-conjugated molecule (polythiophene) connected either to model semi-infinite Ni wires or to realistic Ni(111) electrodes. It is also predicted that such atomic-scale junctions should lead to very high (ideally, infinite) magneto-resistance ratios since the electric current gets fully blocked if two electrodes have antiparallel magnetic alignment.
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Affiliation(s)
- Alexander Smogunov
- Service de Physique de l'Etat Condensé DSM/IRAMIS/SPEC (CNRS UMR 3680), CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Yannick J Dappe
- Service de Physique de l'Etat Condensé DSM/IRAMIS/SPEC (CNRS UMR 3680), CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
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