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Lee J, Kim E, Cho J, Seok H, Woo G, Yu D, Jung G, Hwangbo H, Na J, Im I, Kim T. Remote-Controllable Interfacial Electron Tunneling at Heterogeneous Molecular Junctions via Tip-Induced Optoelectrical Engineering. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2305512. [PMID: 38057140 PMCID: PMC10837351 DOI: 10.1002/advs.202305512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/31/2023] [Indexed: 12/08/2023]
Abstract
Molecular electronics enables functional electronic behavior via single molecules or molecular self-assembled monolayers, providing versatile opportunities for hybrid molecular-scale electronic devices. Although various molecular junction structures are constructed to investigate charge transfer dynamics, significant challenges remain in terms of interfacial charging effects and far-field background signals, which dominantly block the optoelectrical observation of interfacial charge transfer dynamics. Here, tip-induced optoelectrical engineering is presented that synergistically correlates photo-induced force microscopy and Kelvin probe force microscopy to remotely control and probe the interfacial charge transfer dynamics with sub-10 nm spatial resolution. Based on this approach, the optoelectrical origin of metal-molecule interfaces is clearly revealed by the nanoscale heterogeneity of the tip-sample interaction and optoelectrical reactivity, which theoretically aligned with density functional theory calculations. For a practical device-scale demonstration of tip-induced optoelectrical engineering, interfacial tunneling is remotely controlled at a 4-inch wafer-scale metal-insulator-metal capacitor, facilitating a 5.211-fold current amplification with the tip-induced electrical field. In conclusion, tip-induced optoelectrical engineering provides a novel strategy to comprehensively understand interfacial charge transfer dynamics and a non-destructive tunneling control platform that enables real-time and real-space investigation of ultrathin hybrid molecular systems.
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Affiliation(s)
- Jinhyoung Lee
- School of Mechanical Engineering, Sungkyunkwan University (SKKU), Suwon-si, Gyeonggi-do, 16419, Republic of Korea
| | - Eungchul Kim
- AVP process development team, Samsung Electronics, Cheonan-si, Chungcheongnam-do, 31086, South Korea
| | - Jinill Cho
- School of Mechanical Engineering, Sungkyunkwan University (SKKU), Suwon-si, Gyeonggi-do, 16419, Republic of Korea
| | - Hyunho Seok
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Nano Science and Technology, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Gunhoo Woo
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Nano Science and Technology, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Dayoung Yu
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Nano Science and Technology, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Gooeun Jung
- Park Systems Corp, R&D Center, Suwon, 16229, Republic of Korea
| | - Hyeon Hwangbo
- Park Systems Corp, R&D Center, Suwon, 16229, Republic of Korea
| | - Jinyoung Na
- Park Systems Corp, R&D Center, Suwon, 16229, Republic of Korea
| | - Inseob Im
- Park Systems Corp, R&D Center, Suwon, 16229, Republic of Korea
| | - Taesung Kim
- School of Mechanical Engineering, Sungkyunkwan University (SKKU), Suwon-si, Gyeonggi-do, 16419, Republic of Korea
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Nano Science and Technology, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Nano Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea
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2
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De Sousa JA, Pfattner R, Gutiérrez D, Jutglar K, Bromley ST, Veciana J, Rovira C, Mas-Torrent M, Fabre B, Crivillers N. Stable Organic Radical for Enhancing Metal-Monolayer-Semiconductor Junction Performance. ACS APPLIED MATERIALS & INTERFACES 2023; 15:4635-4642. [PMID: 36642951 PMCID: PMC9949700 DOI: 10.1021/acsami.2c15690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
The preparation of monolayers based on an organic radical and its diamagnetic counterpart has been pursued on hydrogen-terminated silicon surfaces. The functional monolayers have been investigated as solid-state metal/monolayer/semiconductor (MmS) junctions showing a characteristic diode behavior which is tuned by the electronic characteristics of the organic molecule. The eutectic gallium-indium liquid metal is used as a top electrode to perform the transport measurements and the results clearly indicate that the SOMO-SUMO molecular orbitals impact the device performance. The junction incorporating the radical shows an almost two orders of magnitude higher rectification ratio (R(|J1V/J-1V|) = 104.04) in comparison with the nonradical one (R(|J1V/J-1V|) = 102.30). The high stability of the fabricated MmS allows the system to be interrogated under irradiation, evidencing that at the wavelength where the photon energy is close to the band gap of the radical there is a clear enhancement of the photoresponse. This is translated into an increase of the photosensitivity (Sph) value from 68.7 to 269.0 mA/W for the nonradical and radical based systems, respectively.
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Affiliation(s)
- J. Alejandro De Sousa
- Institut
de Ciència de Materials de Barcelona (ICMAB, CSIC), Campus de la UAB s/n, Bellaterra 081093, Spain
- Laboratorio
de Electroquímica, Departamento de Química, Facultad
de Ciencias, Universidad de los Andes, 5101 Mérida, Venezuela
| | - Raphael Pfattner
- Institut
de Ciència de Materials de Barcelona (ICMAB, CSIC), Campus de la UAB s/n, Bellaterra 081093, Spain
| | - Diego Gutiérrez
- Institut
de Ciència de Materials de Barcelona (ICMAB, CSIC), Campus de la UAB s/n, Bellaterra 081093, Spain
| | - Kilian Jutglar
- Departament
de Ciència de Materials i Química Física &
Institut de Química Teòrica i Computacional (IQTC), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Stefan T. Bromley
- Departament
de Ciència de Materials i Química Física &
Institut de Química Teòrica i Computacional (IQTC), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain
- Institució
Catalana de Recerca i Estudis Avançats (ICREA), E-08010 Barcelona, Spain
| | - Jaume Veciana
- Institut
de Ciència de Materials de Barcelona (ICMAB, CSIC), Campus de la UAB s/n, Bellaterra 081093, Spain
| | - Concepció Rovira
- Institut
de Ciència de Materials de Barcelona (ICMAB, CSIC), Campus de la UAB s/n, Bellaterra 081093, Spain
| | - Marta Mas-Torrent
- Institut
de Ciència de Materials de Barcelona (ICMAB, CSIC), Campus de la UAB s/n, Bellaterra 081093, Spain
| | - Bruno Fabre
- Univ
Rennes, CNRS, ISCR (Institut
des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France
| | - Núria Crivillers
- Institut
de Ciència de Materials de Barcelona (ICMAB, CSIC), Campus de la UAB s/n, Bellaterra 081093, Spain
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3
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Zhao Z, Soni S, Lee T, Nijhuis CA, Xiang D. Smart Eutectic Gallium-Indium: From Properties to Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2203391. [PMID: 36036771 DOI: 10.1002/adma.202203391] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/30/2022] [Indexed: 05/27/2023]
Abstract
Eutectic gallium-indium (EGaIn), a liquid metal with a melting point close to or below room temperature, has attracted extensive attention in recent years due to its excellent properties such as fluidity, high conductivity, thermal conductivity, stretchability, self-healing capability, biocompatibility, and recyclability. These features of EGaIn can be adjusted by changing the experimental condition, and various composite materials with extended properties can be further obtained by mixing EGaIn with other materials. In this review, not only the are unique properties of EGaIn introduced, but also the working principles for the EGaIn-based devices are illustrated and the developments of EGaIn-related techniques are summarized. The applications of EGaIn in various fields, such as flexible electronics (sensors, antennas, electronic circuits), molecular electronics (molecular memory, opto-electronic switches, or reconfigurable junctions), energy catalysis (heat management, motors, generators, batteries), biomedical science (drug delivery, tumor therapy, bioimaging and neural interfaces) are reviewed. Finally, a critical discussion of the main challenges for the development of EGaIn-based techniques are discussed, and the potential applications in new fields are prospected.
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Affiliation(s)
- Zhibin Zhao
- Institute of Modern Optics and Center of Single Molecule Sciences, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, 300350, Tianjin, P. R. China
| | - Saurabh Soni
- Department of Molecules and Materials, MESA+ Institute for Nanotechnology, Molecules Center and Center for Brain-Inspired Nano Systems, Faculty of Science and Technology, University of Twente, Enschede, 7500 AE, The Netherlands
| | - Takhee Lee
- Department of Physics and Astronomy, Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea
| | - Christian A Nijhuis
- Department of Molecules and Materials, MESA+ Institute for Nanotechnology, Molecules Center and Center for Brain-Inspired Nano Systems, Faculty of Science and Technology, University of Twente, Enschede, 7500 AE, The Netherlands
| | - Dong Xiang
- Institute of Modern Optics and Center of Single Molecule Sciences, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, 300350, Tianjin, P. R. China
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4
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Estimating the Number of Molecules in Molecular Junctions Merely Based on the Low Bias Tunneling Conductance at Variable Temperature. Int J Mol Sci 2022; 23:ijms232314985. [PMID: 36499309 PMCID: PMC9737784 DOI: 10.3390/ijms232314985] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 11/23/2022] [Accepted: 11/25/2022] [Indexed: 12/05/2022] Open
Abstract
Temperature (T) dependent conductance G=G(T) data measured in molecular junctions are routinely taken as evidence for a two-step hopping mechanism. The present paper emphasizes that this is not necessarily the case. A curve of lnG versus 1/T decreasing almost linearly (Arrhenius-like regime) and eventually switching to a nearly horizontal plateau (Sommerfeld regime), or possessing a slope gradually decreasing with increasing 1/T is fully compatible with a single-step tunneling mechanism. The results for the dependence of G on T presented include both analytical exact and accurate approximate formulas and numerical simulations. These theoretical results are general, also in the sense that they are not limited, e.g., to the (single molecule electromigrated (SET) or large area EGaIn) fabrication platforms, which are chosen for exemplification merely in view of the available experimental data needed for analysis. To be specific, we examine in detail transport measurements for molecular junctions based on ferrocene (Fc). As a particularly important finding, we show how the present analytic formulas for G=G(T) can be utilized to compute the ratio f=Aeff/An between the effective and nominal areas of large area Fc-based junctions with an EGaIn top electrode. Our estimate of f≈0.6×10-4 is comparable with previously reported values based on completely different methods for related large area molecular junctions.
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5
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Park S, Yoon HJ. Thermal and Thermoelectric Properties of SAM-Based Molecular Junctions. ACS APPLIED MATERIALS & INTERFACES 2021; 14:22818-22825. [PMID: 34961308 DOI: 10.1021/acsami.1c20840] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In molecular thermoelectrics, the thermopower of molecular junctions is closely interlinked with their thermal properties; however, the detailed relationship between them remains uncertain. This study systematically investigates the thermal properties of self-assembled monolayer (SAM)-based molecular junctions and relates them to the thermoelectric performance of the junctions. The electrode temperatures for the bare AuTS, AuTS/EGaIn, and AuTS/TPT SAM//Ga2O3/EGaIn samples placed on a hot chuck were measured under different conditions, such as air vs vacuum and the presence and absence of thermal grease, which generates a heat conduction channel from a hot chuck to gold. It was revealed that the SAM was the most efficient thermal resistor, which was responsible for the creation of a temperature differential (ΔT) across the junction; ΔT in an air atmosphere is overestimated to some extent, and air mainly contributes to large dispersions of thermovoltage (ΔV) data. While junction measurements in air were possible at low ΔT (up to 13 K), the new optimal condition, under a vacuum and with thermal grease, allowed us to examine a wide temperature range up to ΔT = 40 K and obtain a more reliable Seebeck coefficient (S, μV/K). The value of S under the new condition was ∼1.4 times higher than that measured in air without thermal grease. Our study shows the potential of liquid-metal-based junctions to reliably investigate heat conduction across nanometer-thick organic films and elaborates on how the thermal properties of molecular junctions affect their thermoelectric performance.
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Affiliation(s)
- Sohyun Park
- Department of Chemistry, Korea University, Seoul 02841, Korea
| | - Hyo Jae Yoon
- Department of Chemistry, Korea University, Seoul 02841, Korea
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6
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Shi J, Jiang F, Long S, Lu Z, Liu T, Zheng H, Shi J, Yang Y, Hong W, Tian ZQ. The influence of water on the charge transport through self-assembled monolayers junctions fabricated by EGaIn technique. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.139304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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7
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Scaccabarozzi AD, Basu A, Aniés F, Liu J, Zapata-Arteaga O, Warren R, Firdaus Y, Nugraha MI, Lin Y, Campoy-Quiles M, Koch N, Müller C, Tsetseris L, Heeney M, Anthopoulos TD. Doping Approaches for Organic Semiconductors. Chem Rev 2021; 122:4420-4492. [PMID: 34793134 DOI: 10.1021/acs.chemrev.1c00581] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Electronic doping in organic materials has remained an elusive concept for several decades. It drew considerable attention in the early days in the quest for organic materials with high electrical conductivity, paving the way for the pioneering work on pristine organic semiconductors (OSCs) and their eventual use in a plethora of applications. Despite this early trend, however, recent strides in the field of organic electronics have been made hand in hand with the development and use of dopants to the point that are now ubiquitous. Here, we give an overview of all important advances in the area of doping of organic semiconductors and their applications. We first review the relevant literature with particular focus on the physical processes involved, discussing established mechanisms but also newly proposed theories. We then continue with a comprehensive summary of the most widely studied dopants to date, placing particular emphasis on the chemical strategies toward the synthesis of molecules with improved functionality. The processing routes toward doped organic films and the important doping-processing-nanostructure relationships, are also discussed. We conclude the review by highlighting how doping can enhance the operating characteristics of various organic devices.
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Affiliation(s)
- Alberto D Scaccabarozzi
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955, Saudi Arabia
| | - Aniruddha Basu
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955, Saudi Arabia
| | - Filip Aniés
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, U.K
| | - Jian Liu
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg 412 96, Sweden
| | - Osnat Zapata-Arteaga
- Materials Science Institute of Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Spain
| | - Ross Warren
- Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Yuliar Firdaus
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955, Saudi Arabia.,Research Center for Electronics and Telecommunication, Indonesian Institute of Science, Jalan Sangkuriang Komplek LIPI Building 20 level 4, Bandung 40135, Indonesia
| | - Mohamad Insan Nugraha
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955, Saudi Arabia
| | - Yuanbao Lin
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955, Saudi Arabia
| | - Mariano Campoy-Quiles
- Materials Science Institute of Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Spain
| | - Norbert Koch
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Kekulé-Strasse 5, 12489 Berlin, Germany.,Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
| | - Christian Müller
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg 412 96, Sweden
| | - Leonidas Tsetseris
- Department of Physics, National Technical University of Athens, Athens GR-15780, Greece
| | - Martin Heeney
- Department of Chemistry and Centre for Processable Electronics, Imperial College London, London W12 0BZ, U.K
| | - Thomas D Anthopoulos
- King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Thuwal 23955, Saudi Arabia
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8
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Chen X, Annadata HV, Kretz B, Zharnikov M, Chi X, Yu X, Egger DA, Nijhuis CA. Interplay of Collective Electrostatic Effects and Level Alignment Dictates the Tunneling Rates across Halogenated Aromatic Monolayer Junctions. J Phys Chem Lett 2019; 10:4142-4147. [PMID: 31260324 DOI: 10.1021/acs.jpclett.9b00387] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Predictions about the electrical conductance across molecular junctions based on self-assembled monolayers (SAMs) are often made from the SAM precursor properties. Collective electrostatic effects, however, in a densely packed SAM can override these predictions. We studied, experimentally and theoretically, molecular tunneling junctions based on thiolate SAMs with an aromatic biphenyl backbone and variable, highly polarizable halogen termini X (S-(C6H5)2X; X = H, F, Cl, Br, or I). We found that the halogen-terminated systems show tunneling rates and dielectric behavior that are independent of X despite the large change in the electronegativity of the terminal atom. Using density functional theory, we show that collective electrostatic effects result in modulations of the electrostatic potential that are strongly confined spatially along the direction of charge transport, thereby rendering the role of the halogen atoms insignificant for SAMs with conjugated backbones.
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Affiliation(s)
- Xiaoping Chen
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543 , Singapore
| | - Harshini V Annadata
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543 , Singapore
| | - Bernhard Kretz
- Institute of Theoretical Physics , University of Regensburg , Universitätsstraße 31, 93040 Regensburg , Germany
- Department of Physics , Technical University of Munich , 85748 Garching , Germany
| | - Michael Zharnikov
- Angewandte Physikalische Chemie , Universität Heidelberg , Im Neuenheimer Feld 253 , 69120 Heidelberg , Germany
| | - Xiao Chi
- Singapore Synchrotron Light Source , National University of Singapore , 5 Research Link , Singapore 117603 , Singapore
| | - Xiaojiang Yu
- Singapore Synchrotron Light Source , National University of Singapore , 5 Research Link , Singapore 117603 , Singapore
| | - David A Egger
- Institute of Theoretical Physics , University of Regensburg , Universitätsstraße 31, 93040 Regensburg , Germany
- Department of Physics , Technical University of Munich , 85748 Garching , Germany
| | - Christian A Nijhuis
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543 , Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre , National University of Singapore , 6 Science Drive 2 , Singapore 117546 , Singapore
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9
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Chen X, Hu H, Trasobares J, Nijhuis CA. Rectification Ratio and Tunneling Decay Coefficient Depend on the Contact Geometry Revealed by in Situ Imaging of the Formation of EGaIn Junctions. ACS APPLIED MATERIALS & INTERFACES 2019; 11:21018-21029. [PMID: 31117425 DOI: 10.1021/acsami.9b02033] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This paper describes how the intensive (tunneling decay coefficient β and rectification ratio R) and extensive (current density J) properties of Ag-S(CH2) n-1CH3//GaO x/EGaIn junctions ( n = 10, 14, 18) and molecular diodes of the form of Ag-S(CH2)11Fc//GaO x/EGaIn depend on Ageo, the contact area between the self-assembled monolayer and the cone-shaped EGaIn tip. Large junctions with Ageo ≥ 1000 μm2 are unreliable and defects, such as pinholes, dominate the charge transport characteristics. For S(CH2)11Fc SAMs, R decreases from 130 to unity with increasing Ageo due to an increase in the leakage current (the current flowing across the junction at reverse bias when the diodes block current flow). The value of β decreases from 1.00 ± 0.06 n-1 to 0.70 ± 0.03 n-1 with increasing Ageo which also indicates that large junctions suffer from defects. Small junctions with Ageo ≤ 300 μm2 are not stable due to the high surface tension of the bulk EGaIn resulting in unstable EGaIn tips. In addition, the contact area for such small junctions is dominated by the rough tip apex reducing the effective contact area and reproducibility significantly. The contact area of very large junctions is dominated by the relatively smooth side walls of the tips. Our findings show that there is an optimum range for the value of Ageo between 300-500 μm2 where the electrical properties of the junctions are dominated by molecular effects. In this range of Ageo, the value of J (defined by I/ Ageo where I is the measured current) increases with Ageo until it plateaus for junctions with Ageo > 1000 μm2 in agreement with recently reported findings by the Whitesides group. In this regime reproducible measurements of J can be obtained provided Ageo is kept constant.
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Affiliation(s)
- Xiaoping Chen
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543 , Singapore
| | - Hongting Hu
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543 , Singapore
| | - Jorge Trasobares
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543 , Singapore
| | - Christian A Nijhuis
- Department of Chemistry , National University of Singapore , 3 Science Drive 3 , Singapore 117543 , Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre , National University of Singapore , 6 Science Drive 2 , Singapore 117546 , Singapore
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10
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Sangeeth CSS, Jiang L, Nijhuis CA. Bottom-electrode induced defects in self-assembled monolayer (SAM)-based tunnel junctions affect only the SAM resistance, not the contact resistance or SAM capacitance. RSC Adv 2018; 8:19939-19949. [PMID: 35541643 PMCID: PMC9080736 DOI: 10.1039/c8ra01513a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 05/14/2018] [Indexed: 12/22/2022] Open
Abstract
In large area molecular junctions, defects are always present and can be caused by impurities and/or defects in the electrode materials and/or SAMs, but how they affect the electrical characteristics of junctions has rarely been studied. Usually, junctions are characterized by two-terminal current–voltage measurements where only the total current across the junction is measured, but with these methods one cannot distinguish how the individual components of the junctions are altered by the defects. Here we show that the roughness of the bottom-electrode is a crucial factor in determining the electrical properties of self-assembled monolayer (SAM)-based junctions. We used potentiodynamic impedance spectroscopy to reveal which components of the junctions are altered by defective bottom electrodes because this method allows for direct determination of all components that impede charge transport in the equivalent circuit of the junctions. We intentionally introduced defects via the roughness of the bottom electrode and found that these defects lower the SAM resistance but they do not alter the capacitance of the SAM or the contact resistance of the junction. In other words, defective junctions can be seen as “leaky capacitors” resulting in an underestimation of the SAM resistance of two orders of magnitude. These results help to improve the interpretation of data generated by SAM-based junctions and explain in part the observed large spread of reported tunneling rates for the same molecules measured across different platforms. In large area molecular junctions, defects are always present and can be caused by impurities and/or defects in the electrode materials and/or SAMs, but how they affect the electrical characteristics of junctions has rarely been studied.![]()
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Affiliation(s)
| | - Li Jiang
- Department of Chemistry
- National University of Singapore
- Singapore 117543
- Singapore
| | - Christian A. Nijhuis
- Department of Chemistry
- National University of Singapore
- Singapore 117543
- Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre
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11
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Jeong H, Kim D, Xiang D, Lee T. High-Yield Functional Molecular Electronic Devices. ACS NANO 2017; 11:6511-6548. [PMID: 28578582 DOI: 10.1021/acsnano.7b02967] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
An ultimate goal of molecular electronics, which seeks to incorporate molecular components into electronic circuit units, is to generate functional molecular electronic devices using individual or ensemble molecules to fulfill the increasing technical demands of the miniaturization of traditional silicon-based electronics. This review article presents a summary of recent efforts to pursue this ultimate aim, covering the development of reliable device platforms for high-yield ensemble molecular junctions and their utilization in functional molecular electronic devices, in which distinctive electronic functionalities are observed due to the functional molecules. In addition, other aspects pertaining to the practical application of molecular devices such as manufacturing compatibility with existing complementary metal-oxide-semiconductor technology, their integration, and flexible device applications are also discussed. These advances may contribute to a deeper understanding of charge transport characteristics through functional molecular junctions and provide a desirable roadmap for future practical molecular electronics applications.
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Affiliation(s)
- Hyunhak Jeong
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University , Seoul 08826, Korea
| | - Dongku Kim
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University , Seoul 08826, Korea
| | - Dong Xiang
- Key Laboratory of Optical Information Science and Technology, Institute of Modern Optics, College of Electronic Information and Optical Engineering, Nankai University , Tianjin 300071, China
| | - Takhee Lee
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University , Seoul 08826, Korea
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12
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Baghbanzadeh M, Bowers CM, Rappoport D, Żaba T, Yuan L, Kang K, Liao KC, Gonidec M, Rothemund P, Cyganik P, Aspuru-Guzik A, Whitesides GM. Anomalously Rapid Tunneling: Charge Transport across Self-Assembled Monolayers of Oligo(ethylene glycol). J Am Chem Soc 2017; 139:7624-7631. [DOI: 10.1021/jacs.7b02770] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mostafa Baghbanzadeh
- Department
of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Carleen M. Bowers
- Department
of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Dmitrij Rappoport
- Department
of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Tomasz Żaba
- Smoluchowski
Institute of Physics, Jagiellonian University, Lojasiewicza 11, 30-348 Krakow, Poland
| | - Li Yuan
- Department
of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Kyungtae Kang
- Department
of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Kung-Ching Liao
- Department
of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Mathieu Gonidec
- Department
of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
- CNRS, Université de Bordeaux, ICMCB,
UPR 9048, F-33600 Pessac, France
| | - Philipp Rothemund
- Department
of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Piotr Cyganik
- Smoluchowski
Institute of Physics, Jagiellonian University, Lojasiewicza 11, 30-348 Krakow, Poland
| | - Alan Aspuru-Guzik
- Department
of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - George M. Whitesides
- Department
of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
- Kavli Institute for Bionano Science & Technology, School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, United States
- Wyss
Institute of Biologically Inspired Engineering, Harvard University 60
Oxford Street Cambridge, Massachusetts 02138, United States
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13
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Hacker CA, Bruce RC, Pookpanratana SJ. Interface Engineering for Nanoelectronics. ECS TRANSACTIONS 2017; 80:119-131. [PMID: 29276553 PMCID: PMC5740487 DOI: 10.1149/08001.0119ecst] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Innovation in the electronics industry is tied to interface engineering as devices increasingly incorporate new materials and shrink. Molecular layers offer a versatile means of tuning interfacial electronic, chemical, physical, and magnetic properties enabled by a wide variety of molecules available. This paper will describe three instances where we manipulate molecular interfaces with a specific focus on the nanometer scale characterization and the impact on the resulting performance. The three primary themes include, 1-designer interfaces, 2-electronic junction formation, and 3-advancing metrology for nanoelectronics. We show the ability to engineer interfaces through a variety of techniques and demonstrate the impact on technologies such as molecular memory and spin injection for organic electronics. Underpinning the successful modification of interfaces is the ability to accurately characterize the chemical and electronic properties and we will highlight some measurement advances key to our understanding of the interface engineering for nanoelectronics.
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Affiliation(s)
- C A Hacker
- Engineering Physics Division, Physical Measurements Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - R C Bruce
- Engineering Physics Division, Physical Measurements Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - S J Pookpanratana
- Engineering Physics Division, Physical Measurements Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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14
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Thompson D, Nijhuis CA. Even the Odd Numbers Help: Failure Modes of SAM-Based Tunnel Junctions Probed via Odd-Even Effects Revealed in Synchrotrons and Supercomputers. Acc Chem Res 2016; 49:2061-2069. [PMID: 27598413 DOI: 10.1021/acs.accounts.6b00256] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This Account describes a body of research in atomic level design, synthesis, physicochemical characterization, and macroscopic electrical testing of molecular devices made from ferrocene-functionalized alkanethiol molecules, which are molecular diodes, with the aim to identify, and resolve, the failure modes that cause leakage currents. The mismatch in size between the ferrocene headgroup and alkane rod makes waxlike highly dynamic self-assembled monolayers (SAMs) on coinage metals that show remarkable atomic-scale sensitivity in their electrical properties. Our results make clear that molecular tunnel junction devices provide an excellent testbed to probe the electronic and supramolecular structures of SAMs on inorganic substrates. Contacting these SAMs to a eutectic "EGaIn" alloy top-electrode, we designed highly stable long-lived molecular switches of the form electrode-SAM-electrode with robust rectification ratios of up to 3 orders of magnitude. The graphic that accompanies this conspectus displays a computed SAM packing structure, illustrating the lollipop shape of the molecules that gives dynamic SAM supramolecular structures and also the molecule-electrode van der Waals (vdW) contacts that must be controlled to form good SAM-based devices. In this Account, we first trace the evolution of SAM-based electronic devices and rationalize their operation using energy level diagrams. We describe the measurement of device properties using near edge X-ray absorption fine structure spectroscopy, cyclic voltammetry, and X-ray photoelectron spectroscopy complemented by molecular dynamics and electronic structure calculations together with large numbers of electrical measurements. We discuss how data obtained from these combined experimental/simulation codesign studies demonstrate control over the supramolecular and electronic structure of the devices, tuning odd-even effects to optimize inherent packing tendencies of the molecules in order to minimize leakage currents in the junctions. It is now possible, but still very costly to create atomically smooth electrodes and we discuss progress toward masking electrode imperfections using cooperative molecule-electrode contacts that are only accessible by dynamic SAM structures. Finally, the unique ability of SAM devices to achieve simultaneously high and atom-sensitive electrical switching is summarized and discussed. While putting these structures to work as real world electronic devices remains very challenging, we speculate on the scientific and technological advances that are required to further improve electronic and supramolecular structure, toward the creation of high yields of long-lived molecular devices with (very) large, reproducible rectification ratios.
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Affiliation(s)
- Damien Thompson
- Department
of Physics, Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland
| | - Christian A. Nijhuis
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
- Centre for Advanced 2D Materials, National University of Singapore, 6 Science Drive 2, Singapore 117546
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15
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Sangeeth CSS, Demissie AT, Yuan L, Wang T, Frisbie CD, Nijhuis CA. Comparison of DC and AC Transport in 1.5-7.5 nm Oligophenylene Imine Molecular Wires across Two Junction Platforms: Eutectic Ga-In versus Conducting Probe Atomic Force Microscope Junctions. J Am Chem Soc 2016; 138:7305-14. [PMID: 27172452 DOI: 10.1021/jacs.6b02039] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have utilized DC and AC transport measurements to measure the resistance and capacitance of thin films of conjugated oligophenyleneimine (OPI) molecules ranging from 1.5 to 7.5 nm in length. These films were synthesized on Au surfaces utilizing the imine condensation chemistry between terephthalaldehyde and 1,4-benzenediamine. Near edge X-ray absorption fine structure (NEXAFS) spectroscopy yielded molecular tilt angles of 33-43°. To probe DC and AC transport, we employed Au-S-OPI//GaOx/EGaIn junctions having contact areas of 9.6 × 10(2) μm(2) (10(9) nm(2)) and compared to previously reported DC results on the same OPI system obtained using Au-S-OPI//Au conducting probe atomic force microscopy (CP-AFM) junctions with 50 nm(2) areas. We found that intensive observables agreed very well across the two junction platforms. Specifically, the EGaIn-based junctions showed: (i) a crossover from tunneling to hopping transport at molecular lengths near 4 nm; (ii) activated transport for wires >4 nm in length with an activation energy of 0.245 ± 0.008 eV for OPI-7; (iii) exponential dependence of conductance with molecular length with a decay constant β = 2.84 ± 0.18 nm(-1) (DC) and 2.92 ± 0.13 nm(-1) (AC) in the tunneling regime, and an apparent β = 1.01 ± 0.08 nm(-1) (DC) and 0.99 ± 0.11 nm(-1) (AC) in the hopping regime; (iv) previously unreported dielectric constant of 4.3 ± 0.2 along the OPI wires. However, the absolute resistances of Au-S-OPI//GaOx/EGaIn junctions were approximately 100 times higher than the corresponding CP-AFM junctions due to differences in metal-molecule contact resistances between the two platforms.
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Affiliation(s)
- C S Suchand Sangeeth
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
| | - Abel T Demissie
- Department of Chemical Engineering and Materials Science, University of Minnesota , 421 Washington Avenue SE, Minneapolis, Minnesota 55455, United States
| | - Li Yuan
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
| | - Tao Wang
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
| | - C Daniel Frisbie
- Department of Chemical Engineering and Materials Science, University of Minnesota , 421 Washington Avenue SE, Minneapolis, Minnesota 55455, United States
| | - Christian A Nijhuis
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543.,Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, Singapore 117546
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16
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Song P, Yuan L, Roemer M, Jiang L, Nijhuis CA. Supramolecular vs Electronic Structure: The Effect of the Tilt Angle of the Active Group in the Performance of a Molecular Diode. J Am Chem Soc 2016; 138:5769-72. [DOI: 10.1021/jacs.6b02208] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Peng Song
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543
| | - Li Yuan
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543
| | - Max Roemer
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543
| | - Li Jiang
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543
| | - Christian A. Nijhuis
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543
- Centre
for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore, 117546
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17
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Song P, Sangeeth CSS, Thompson D, Du W, Loh KP, Nijhuis CA. Noncovalent Self-Assembled Monolayers on Graphene as a Highly Stable Platform for Molecular Tunnel Junctions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:631-9. [PMID: 26618274 DOI: 10.1002/adma.201504207] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 10/02/2015] [Indexed: 05/16/2023]
Abstract
Monolayer graphene is used as the bottom electrode to fabricate stable and high-quality self-assembled monolayer (SAM)-based tunnel junctions. The SAMs are formed on graphene via noncovalent bonds without altering the structure of the graphene. This work paves the way to new types of molecular electronic junctions based on 2D materials.
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Affiliation(s)
- Peng Song
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
| | - C S Suchand Sangeeth
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
| | - Damien Thompson
- Materials and Surface Science Institute and Department of Physics and Energy, University of Limerick, Co. Limerick, Ireland
| | - Wei Du
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
| | - Kian Ping Loh
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
| | - Christian A Nijhuis
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
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18
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Garrigues AR, Yuan L, Wang L, Singh S, del Barco E, Nijhuis CA. Temperature dependent charge transport across tunnel junctions of single-molecules and self-assembled monolayers: a comparative study. Dalton Trans 2016; 45:17153-17159. [PMID: 27775126 DOI: 10.1039/c6dt03204d] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In this work we present a comparative study of the temperature behavior of charge current in both single-molecule transistors and self-assembled monolayer-based tunnel junctions with ferrocene molecules.
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Affiliation(s)
| | - Li Yuan
- Department of Chemistry
- National University of Singapore
- Singapore 117543
- Singapore
| | - Lejia Wang
- Department of Chemistry
- National University of Singapore
- Singapore 117543
- Singapore
- School of Chemical Engineering
| | | | | | - Christian A. Nijhuis
- Department of Chemistry
- National University of Singapore
- Singapore 117543
- Singapore
- Centre for Advanced 2D Materials
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19
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Wang D, Fracasso D, Nurbawono A, Annadata HV, Sangeeth CSS, Yuan L, Nijhuis CA. Tuning the Tunneling Rate and Dielectric Response of SAM-Based Junctions via a Single Polarizable Atom. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:6689-6695. [PMID: 26414779 DOI: 10.1002/adma.201502968] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 08/16/2015] [Indexed: 06/05/2023]
Abstract
The dielectric response and electrical properties of junctions based on self-assembled monolayers (SAMs) of the form S(CH2)11X can be controlled by changing the polarizability of X (here X = H, F, Cl, Br, or I). A 1000-fold increase in the tunneling rate and a four-fold increase of the dielectric constant (ε r ) with increasing polarizability of X are found.
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Affiliation(s)
- Dandan Wang
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
| | - Davide Fracasso
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
| | - Argo Nurbawono
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117551, Singapore
| | - Harshini V Annadata
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
| | - C S Suchand Sangeeth
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
| | - Li Yuan
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
| | - Christian A Nijhuis
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
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20
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Jiang L, Sangeeth CSS, Yuan L, Thompson D, Nijhuis CA. One-Nanometer Thin Monolayers Remove the Deleterious Effect of Substrate Defects in Molecular Tunnel Junctions. NANO LETTERS 2015; 15:6643-6649. [PMID: 26340232 DOI: 10.1021/acs.nanolett.5b02481] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Defects in self-assembled monolayer (SAMs) based junctions cause the largest deviation between predicted and measured values of the tunnelling current. We report the remarkable, seemingly counterintuitive finding that shorter, less-ordered SAMs provide, unlike taller crystalline-like SAMs, higher quality tunnelling barriers on defective substrates, which points to self-repair of liquid-like SAMs on defects. The molecular dynamics show that short-chain molecules can more easily rotate into low-density boundary regions and smoothen out defects than thick solid-like SAMs. Our findings point to an attractive means of removing their deleterious effects simply by using flexible molecules.
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Affiliation(s)
- Li Jiang
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore
| | - C S Suchand Sangeeth
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore
| | - Li Yuan
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore
| | - Damien Thompson
- Materials and Surface Science Institute and Department of Physics and Energy, University of Limerick , Co. Limerick, Ireland
| | - Christian A Nijhuis
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore
- Solar Energy Research Institute of Singapore (SERIS), 7 Engineering Drive 1, National University of Singapore , Singapore 117574, Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore , 6 Science Drive 2, Singapore 117546, Singapore
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21
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Jiang L, Sangeeth CSS, Nijhuis CA. The Origin of the Odd–Even Effect in the Tunneling Rates across EGaIn Junctions with Self-Assembled Monolayers (SAMs) of n-Alkanethiolates. J Am Chem Soc 2015; 137:10659-67. [DOI: 10.1021/jacs.5b05761] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Li Jiang
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - C. S. Suchand Sangeeth
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Christian A. Nijhuis
- Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
- Solar
Energy Research Institute of Singapore (SERIS), National University of Singapore, 7 Engineering Drive 1, Singapore 117574, Singapore
- Centre
for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
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