1
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Chaudhry I, Hu G, Ye H, Jensen L. Toward Modeling the Complexity of the Chemical Mechanism in SERS. ACS NANO 2024. [PMID: 39087679 DOI: 10.1021/acsnano.4c07198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2024]
Abstract
Surface-enhanced Raman scattering (SERS) provides detailed information about the binding of molecules at interfaces and their interactions with the local environment due to the large enhancement of Raman scattering. This enhancement arises from a combination of the electromagnetic mechanism (EM) and chemical mechanism (CM). While it is commonly accepted that EM gives rise to most of the enhancement, large spectral changes originate from CM. To elucidate the rich information contained in SERS spectra about molecules at interfaces, a comprehensive understanding of the enhancement mechanisms is necessary. In this Perspective, we discuss the current understanding of the enhancement mechanisms and highlight their interplay in complex local environments. We will also discuss emerging areas where the development of computational and theoretical models is needed with specific attention given to how the CM contributes to the spectral changes. Future efforts in modeling should focus on overcoming the challenges presented in this review in order to capture the complexity of CM in SERS.
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Affiliation(s)
- Imran Chaudhry
- Department of Chemistry, The Pennsylvania State University, 104 Benkovic Building, University Park, Pennsylvania 16802, United States
| | - Gaohe Hu
- Department of Chemistry, The Pennsylvania State University, 104 Benkovic Building, University Park, Pennsylvania 16802, United States
| | - Hepeng Ye
- Department of Chemistry, The Pennsylvania State University, 104 Benkovic Building, University Park, Pennsylvania 16802, United States
| | - Lasse Jensen
- Department of Chemistry, The Pennsylvania State University, 104 Benkovic Building, University Park, Pennsylvania 16802, United States
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2
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Shukla S, Jana S, Gupta A, Ghosh S, Ray SK, Srivastava SK. Photoresponse of Carbon Nanofiber-Based Photodetector and Its Enhancement on CuNi Nanoparticle Adsorption. ACS OMEGA 2024; 9:27232-27247. [PMID: 38947801 PMCID: PMC11209913 DOI: 10.1021/acsomega.4c01546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 04/15/2024] [Accepted: 06/07/2024] [Indexed: 07/02/2024]
Abstract
We explore the photodetection properties of a carbon nanofiber (CNF)-based p-CNF/n-Si heterojunction device in the 400-800 nm wavelength range and investigate the changes brought in by adsorption of CuNi (CN) nanoparticles on the CNFs. The nanoparticles and CN-CNF nanocomposites were synthesized by using chemical hydrothermal routes. The p-type semiconducting nature of the CNFs and nanocomposites was determined using X-ray photoelectron (XPS) and UV-vis spectroscopies. The p-CNF/n-Si device is found to be better than many carbon-nanotube-based devices in terms of its peak responsivity (0.6 A/W) and gain (1.6), with an acceptably moderate peak detectivity (1.3 × 109 Jones) at 450 nm and a -5 V bias. The p-CN-CNF/n-Si device displays an appreciable enhancement in the photoresponse with respect to the p-CNF/n-Si device, with a peak responsivity of 2.8 A/W, peak detectivity of 9.4 × 109 Jones, and gain of 8. With the aid of valence band XPS and Raman spectra, the enhancement is explainable in terms of a CN to CNF charge transfer and the resulting increase in the built-in potential at the heterojunction.
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Affiliation(s)
- Shivam Shukla
- Department
of Physics, Indian Institute of Technology
Kharagpur, Kharagpur WB - 721302, India
| | - Subhajit Jana
- Department
of Physics, Indian Institute of Technology
Kharagpur, Kharagpur WB - 721302, India
| | - Anu Gupta
- Department
of Chemical and Biological Physics, Weizmann
Institute of Science, Rehovot 7610001, Israel
| | - Subhadip Ghosh
- Department
of Physics, Indian Institute of Technology
Kharagpur, Kharagpur WB - 721302, India
| | - Samit K. Ray
- Department
of Physics, Indian Institute of Technology
Kharagpur, Kharagpur WB - 721302, India
| | - Sanjeev K. Srivastava
- Department
of Physics, Indian Institute of Technology
Kharagpur, Kharagpur WB - 721302, India
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3
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de Campos Ferreira R, Sagwal A, Doležal J, Canola S, Merino P, Neuman T, Švec M. Resonant Tip-Enhanced Raman Spectroscopy of a Single-Molecule Kondo System. ACS NANO 2024; 18:13164-13170. [PMID: 38711331 PMCID: PMC11112976 DOI: 10.1021/acsnano.4c02105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/11/2024] [Accepted: 04/24/2024] [Indexed: 05/08/2024]
Abstract
Tip-enhanced Raman spectroscopy (TERS) under ultrahigh vacuum and cryogenic conditions enables exploration of the relations between the adsorption geometry, electronic state, and vibrational fingerprints of individual molecules. TERS capability of reflecting spin states in open-shell molecular configurations is yet unexplored. Here, we use the tip of a scanning probe microscope to lift a perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecule from a metal surface to bring it into an open-shell spin one-half anionic state. We reveal a correlation between the appearance of a Kondo resonance in differential conductance spectroscopy and concurrent characteristic changes captured by the TERS measurements. Through a detailed investigation of various adsorbed and tip-contacted PTCDA scenarios, we infer that the Raman scattering on suspended PTCDA is resonant with a higher excited state. Theoretical simulation of the vibrational spectra enables a precise assignment of the individual TERS peaks to high-symmetry Ag modes, including the fingerprints of the observed spin state. These findings highlight the potential of TERS in capturing complex interactions between charge, spin, and photophysical properties in nanoscale molecular systems and suggest a pathway for designing single-molecule spin-optical devices.
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Affiliation(s)
| | - Amandeep Sagwal
- Institute
of Physics, Czech Academy of Sciences; Cukrovarnická 10/112, Praha 6 CZ16200, Czech Republic
- Faculty
of Mathematics and Physics, Charles University; Ke Karlovu 3, Praha 2 CZ12116. Czech Republic
| | - Jiří Doležal
- Institute
of Physics, Czech Academy of Sciences; Cukrovarnická 10/112, Praha 6 CZ16200, Czech Republic
- Institute
of Physics, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - Sofia Canola
- Institute
of Physics, Czech Academy of Sciences; Cukrovarnická 10/112, Praha 6 CZ16200, Czech Republic
| | - Pablo Merino
- Instituto
de Ciencia de Materiales de Madrid; CSIC, Sor Juana Inés de la Cruz 3, Madrid E28049, Spain
| | - Tomáš Neuman
- Institute
of Physics, Czech Academy of Sciences; Cukrovarnická 10/112, Praha 6 CZ16200, Czech Republic
| | - Martin Švec
- Institute
of Physics, Czech Academy of Sciences; Cukrovarnická 10/112, Praha 6 CZ16200, Czech Republic
- Institute
of Organic Chemistry and Biochemistry, Czech
Academy of Sciences; Flemingovo náměstí 542/2. Praha 6 CZ16000, Czech Republic
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4
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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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5
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Chen L, Yang Z, Lin Q, Li X, Bai J, Hong W. Evolution of Single-Molecule Electronic Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:1988-2004. [PMID: 38227964 DOI: 10.1021/acs.langmuir.3c03104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Single-molecule electronics can fabricate single-molecule devices via the construction of molecule-electrode interfaces and also provide a unique tool to investigate single-molecule scale physicochemical processes at these interfaces. To investigate single-molecule electronic devices with desired functionalities, an understanding of the interface evolution processes in single-molecule devices is essential. In this review, we focus on the evolution of molecule-electrode interface properties, including the background of interface evolution in single-molecule electronics, the construction of different types of single-molecule interfaces, and the regulation methods. Finally, we discuss the perspective of future characterization techniques and applications for single-molecule electronic interfaces.
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Affiliation(s)
- Lichuan Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & College of Materials & IKKEM, Xiamen University, Xiamen 361000, China
| | - Zixian Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & College of Materials & IKKEM, Xiamen University, Xiamen 361000, China
| | - Qichao Lin
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & College of Materials & IKKEM, Xiamen University, Xiamen 361000, China
| | - Xiaohui Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & College of Materials & IKKEM, Xiamen University, Xiamen 361000, China
| | - Jie Bai
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & College of Materials & IKKEM, Xiamen University, Xiamen 361000, China
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & College of Materials & IKKEM, Xiamen University, Xiamen 361000, China
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6
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Litman Y, Bonafé FP, Akkoush A, Appel H, Rossi M. First-Principles Simulations of Tip Enhanced Raman Scattering Reveal Active Role of Substrate on High-Resolution Images. J Phys Chem Lett 2023; 14:6850-6859. [PMID: 37487223 PMCID: PMC10405274 DOI: 10.1021/acs.jpclett.3c01216] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 07/14/2023] [Indexed: 07/26/2023]
Abstract
Tip-enhanced Raman scattering (TERS) has emerged as a powerful tool to obtain subnanometer spatial resolution fingerprints of atomic motion. Theoretical calculations that can simulate the Raman scattering process and provide an unambiguous interpretation of TERS images often rely on crude approximations of the local electric field. In this work, we present a novel and first-principles-based method to compute TERS images by combining Time Dependent Density Functional Theory (TD-DFT) and Density Functional Perturbation Theory (DFPT) to calculate Raman cross sections with realistic local fields. We present TERS results on free-standing benzene and C60 molecules, and on the TCNE molecule adsorbed on Ag(100). We demonstrate that chemical effects on chemisorbed molecules, often ignored in TERS simulations of larger systems, dramatically change the TERS images. This observation calls for the inclusion of chemical effects for predictive theory-experiment comparisons and an understanding of molecular motion at the nanoscale.
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Affiliation(s)
- Yair Litman
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
- MPI
for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Franco P. Bonafé
- MPI
for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Alaa Akkoush
- MPI
for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany
- Fritz
Haber Institute of the Max Planck Society, Faradayweg 4−6, 14195 Berlin, Germany
| | - Heiko Appel
- MPI
for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Mariana Rossi
- MPI
for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany
- Fritz
Haber Institute of the Max Planck Society, Faradayweg 4−6, 14195 Berlin, Germany
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7
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Luo Y, Martin-Jimenez A, Pisarra M, Martin F, Garg M, Kern K. Imaging and controlling coherent phonon wave packets in single graphene nanoribbons. Nat Commun 2023; 14:3484. [PMID: 37311753 DOI: 10.1038/s41467-023-39239-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 06/06/2023] [Indexed: 06/15/2023] Open
Abstract
The motion of atoms is at the heart of any chemical or structural transformation in molecules and materials. Upon activation of this motion by an external source, several (usually many) vibrational modes can be coherently coupled, thus facilitating the chemical or structural phase transformation. These coherent dynamics occur on the ultrafast timescale, as revealed, e.g., by nonlocal ultrafast vibrational spectroscopic measurements in bulk molecular ensembles and solids. Tracking and controlling vibrational coherences locally at the atomic and molecular scales is, however, much more challenging and in fact has remained elusive so far. Here, we demonstrate that the vibrational coherences induced by broadband laser pulses on a single graphene nanoribbon (GNR) can be probed by femtosecond coherent anti-Stokes Raman spectroscopy (CARS) when performed in a scanning tunnelling microscope (STM). In addition to determining dephasing (~440 fs) and population decay times (~1.8 ps) of the generated phonon wave packets, we are able to track and control the corresponding quantum coherences, which we show to evolve on time scales as short as ~70 fs. We demonstrate that a two-dimensional frequency correlation spectrum unequivocally reveals the quantum couplings between different phonon modes in the GNR.
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Affiliation(s)
- Yang Luo
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany
| | - Alberto Martin-Jimenez
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany
| | - Michele Pisarra
- INFN-LNF, Gruppo Collegato di Cosenza, Via P. Bucci, cubo 31C, 87036, Rende (CS), Italy
| | - Fernando Martin
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nano), Faraday 9, Cantoblanco, 28049, Madrid, Spain
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049, Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Manish Garg
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany.
| | - Klaus Kern
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany
- Institut de Physique, Ecole Polytechnique Fédérale de Lausanne, 1015, Lausanne, Switzerland
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8
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Yang B, Chen G, Ghafoor A, Zhang YF, Zhang XB, Li H, Dong XR, Wang RP, Zhang Y, Zhang Y, Dong ZC. Chemical Enhancement and Quenching in Single-Molecule Tip-Enhanced Raman Spectroscopy. Angew Chem Int Ed Engl 2023; 62:e202218799. [PMID: 36719175 DOI: 10.1002/anie.202218799] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/29/2023] [Accepted: 01/30/2023] [Indexed: 02/01/2023]
Abstract
Despite intensive research in surface enhanced Raman spectroscopy (SERS), the influence mechanism of chemical effects on Raman signals remains elusive. Here, we investigate such chemical effects through tip-enhanced Raman spectroscopy (TERS) of a single planar ZnPc molecule with varying but controlled contact environments. TERS signals are found dramatically enhanced upon making a tip-molecule point contact. A combined physico-chemical mechanism is proposed to explain such an enhancement via the generation of a ground-state charge-transfer induced vertical Raman polarizability that is further enhanced by the strong vertical plasmonic field in the nanocavity. In contrast, TERS signals from ZnPc chemisorbed flatly on substrates are found strongly quenched, which is rationalized by the Raman polarizability screening effect induced by interfacial dynamic charge transfer. Our results provide deep insights into the understanding of the chemical effects in TERS/SERS enhancement and quenching.
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Affiliation(s)
- Ben Yang
- Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Gong Chen
- Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Atif Ghafoor
- Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Yu-Fan Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Xian-Biao Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Hang Li
- Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Xiao-Ru Dong
- Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Rui-Pu Wang
- Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Yang Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.,School of Physics and Department of Chemical Physics, University of Science and Technology of China Hefei, Anhui, 230026, China.,Hefei National Laboratory, University of Science and Technology of China, Hefei, 230088, China
| | - Yao Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.,School of Physics and Department of Chemical Physics, University of Science and Technology of China Hefei, Anhui, 230026, China.,Hefei National Laboratory, University of Science and Technology of China, Hefei, 230088, China
| | - Zhen-Chao Dong
- Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.,School of Physics and Department of Chemical Physics, University of Science and Technology of China Hefei, Anhui, 230026, China.,Hefei National Laboratory, University of Science and Technology of China, Hefei, 230088, China
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9
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Lu Y, Yan L, Xi X, Fan W, Du R, Li J, Fu Z, Zhang Z. Selective Raman Enhancement with Electronic Sensitivity in Tip-Enhanced Raman Spectroscopy. J Phys Chem A 2022; 126:9147-9153. [DOI: 10.1021/acs.jpca.2c04929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Affiliation(s)
- Yirui Lu
- School of Physics and Information Technology, Shaanxi Normal University, Xi’an, Shaanxi 710119, China
| | - Lei Yan
- School of Physics and Information Technology, Shaanxi Normal University, Xi’an, Shaanxi 710119, China
| | - Xiangtai Xi
- School of Physics and Information Technology, Shaanxi Normal University, Xi’an, Shaanxi 710119, China
| | - Wenli Fan
- School of Physics and Information Technology, Shaanxi Normal University, Xi’an, Shaanxi 710119, China
| | - Ruhai Du
- School of Physics and Information Technology, Shaanxi Normal University, Xi’an, Shaanxi 710119, China
| | - Jinping Li
- School of Physics and Information Technology, Shaanxi Normal University, Xi’an, Shaanxi 710119, China
| | - Zhengkun Fu
- School of Physics and Information Technology, Shaanxi Normal University, Xi’an, Shaanxi 710119, China
| | - Zhenglong Zhang
- School of Physics and Information Technology, Shaanxi Normal University, Xi’an, Shaanxi 710119, China
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10
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Cirera B, Wolf M, Kumagai T. Joule Heating in Single-Molecule Point Contacts Studied by Tip-Enhanced Raman Spectroscopy. ACS NANO 2022; 16:16443-16451. [PMID: 36197071 DOI: 10.1021/acsnano.2c05642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Heating and cooling in current-carrying molecular junctions is a crucial issue in molecular electronics. The microscopic mechanism involves complex factors such as energy inputs, molecular properties, electrode materials, and molecule-electrode coupling. To gain an in-depth understanding, it is a desired experiment to assess vibrational population that represents the energy distribution stored within the molecule. Here, we demonstrate the direct observation of vibrational heating in a single C60 molecule by means of tip-enhanced Raman spectroscopy (TERS). The heating of respective vibrational modes is monitored by anti-Stokes Raman scattering in the TERS spectra. The precise control of the gap distance in the single-molecule junction allows us to reveal a qualitatively different heating mechanism in distinct electron transport regimes, namely, the tunneling and single-molecule point contact (SMPC) regimes. Strong Joule heating via inelastic electron-vibration scattering occurs in the SMPC regime, whereas optical heating is predominant in the tunneling regime. The strong Joule heating at the SMPC also leads to a pronounced red shift of the Raman peak position and line width broadening. Furthermore, by examining the SMPC with several types of contact surfaces, we show that the heating efficiency is related to the current density at the SMPC and the vibrational dissipation channels into the electrode.
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Affiliation(s)
- Borja Cirera
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195Berlin, Germany
| | - Martin Wolf
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195Berlin, Germany
| | - Takashi Kumagai
- Department of Physical Chemistry, Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195Berlin, Germany
- Center for Mesoscopic Sciences, Institute for Molecular Science, Okazaki444-8585, Japan
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