1
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Luo Y, Sheng S, Pisarra M, Martin-Jimenez A, Martin F, Kern K, Garg M. Selective excitation of vibrations in a single molecule. Nat Commun 2024; 15:6983. [PMID: 39143046 PMCID: PMC11324655 DOI: 10.1038/s41467-024-51419-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Accepted: 08/06/2024] [Indexed: 08/16/2024] Open
Abstract
The capability to excite, probe, and manipulate vibrational modes is essential for understanding and controlling chemical reactions at the molecular level. Recent advancements in tip-enhanced Raman spectroscopies have enabled the probing of vibrational fingerprints in a single molecule with Ångström-scale spatial resolution. However, achieving controllable excitation of specific vibrational modes in individual molecules remains challenging. Here, we demonstrate the selective excitation and probing of vibrational modes in single deprotonated phthalocyanine molecules utilizing resonance Raman spectroscopy in a scanning tunneling microscope. Selective excitation is achieved by finely tuning the excitation wavelength of the laser to be resonant with the vibronic transitions between the molecular ground electronic state and the vibrational levels in the excited electronic state, resulting in the state-selective enhancement of the resonance Raman signal. Our approach contributes to setting the stage for steering chemical transformations in molecules on surfaces by selective excitation of molecular vibrations.
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Affiliation(s)
- Yang Luo
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany.
| | - Shaoxiang Sheng
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany
| | - Michele Pisarra
- Dipartimento di Fisica, Università della Calabria, Via P. Bucci, Cubo 30C, 87036, Rende, CS, Italy
- INFN-LNF, Gruppo Collegato di Cosenza, Via P. Bucci, Cubo 31C, 87036, Rende, CS, Italy
| | - Alberto Martin-Jimenez
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nano), Faraday 9, Cantoblanco, 28049, Madrid, Spain
| | - 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.
| | - 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
| | - Manish Garg
- Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany.
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2
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Wang Z, Yin R, Tang Z, Du H, Liang Y, Wang X, Deng QS, Tan YZ, Zhang Y, Ma C, Tan S, Wang B. Topologically Localized Vibronic Excitations in Second-Layer Graphene Nanoribbons. PHYSICAL REVIEW LETTERS 2024; 133:036401. [PMID: 39094172 DOI: 10.1103/physrevlett.133.036401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 06/06/2024] [Indexed: 08/04/2024]
Abstract
It is of fundamental importance to characterize the intrinsic properties, like the topological end states, in the on-surface synthesized graphene nanoribbons (GNRs), but the strong electronic interaction with the metal substrate usually smears out their characteristic features. Here, we report our approach to investigate the vibronic excitations of the topological end states in self-decoupled second-layer GNRs, which are grown using an on-surface squeezing-induced spillover strategy. The vibronic progressions show highly spatially localized distributions at the second-layer GNR ends, which can be ascribed to the decoupling-extended lifetime of charging through resonant electron tunneling at the topological end states. In combination with theoretical calculations, we assign the vibronic progressions to specific vibrational modes that mediate the vibronic excitations. The spatial distribution of each resolved excitation shows evident characteristics beyond the conventional Franck-Condon picture. Our work by direct growth of second-layer GNRs provides an effective way to explore the interplay between the intrinsic electronic, vibrational, and topological properties.
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Affiliation(s)
| | | | | | | | | | | | - Qing-Song Deng
- Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory for Physical Chemistry of Solid Surfaces, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China
| | - Yuan-Zhi Tan
- Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory for Physical Chemistry of Solid Surfaces, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China
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3
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Rosławska A, Kaiser K, Romeo M, Devaux E, Scheurer F, Berciaud S, Neuman T, Schull G. Submolecular-scale control of phototautomerization. NATURE NANOTECHNOLOGY 2024; 19:738-743. [PMID: 38413791 DOI: 10.1038/s41565-024-01622-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/29/2024] [Indexed: 02/29/2024]
Abstract
Optically activated reactions initiate biological processes such as photosynthesis or vision, but can also control polymerization, catalysis or energy conversion. Methods relying on the manipulation of light at macroscopic and mesoscopic scales are used to control on-surface photochemistry, but do not offer atomic-scale control. Here we take advantage of the confinement of the electromagnetic field at the apex of a scanning tunnelling microscope tip to drive the phototautomerization of a free-base phthalocyanine with submolecular precision. We can control the reaction rate and the relative tautomer population through a change in the laser excitation wavelength or through the tip position. Atomically resolved tip-enhanced photoluminescence spectroscopy and hyperspectral mapping unravel an excited-state mediated process, which is quantitatively supported by a comprehensive theoretical model combining ab initio calculations with a parametric open-quantum-system approach. Our experimental strategy may allow insights in other photochemical reactions and proof useful to control complex on-surface reactions.
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Affiliation(s)
- Anna Rosławska
- Université de Strasbourg, CNRS, IPCMS, Strasbourg, France.
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany.
| | - Katharina Kaiser
- Université de Strasbourg, CNRS, IPCMS, Strasbourg, France
- 4th Physical Institute - Solids and Nanostructures, Georg-August-Universität Göttingen, Göttingen, Germany
| | | | - Eloïse Devaux
- Université de Strasbourg, CNRS, ISIS, Strasbourg, France
| | | | | | - Tomáš Neuman
- Institut des Sciences Moléculaires d'Orsay (ISMO), UMR 8214, CNRS, Université Paris-Saclay, Orsay, France.
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic.
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4
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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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5
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Duan S, Tian G, Luo Y. Theoretical and computational methods for tip- and surface-enhanced Raman scattering. Chem Soc Rev 2024; 53:5083-5117. [PMID: 38596836 DOI: 10.1039/d3cs01070h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Raman spectroscopy is a versatile tool for acquiring molecular structure information. The incorporation of plasmonic fields has significantly enhanced the sensitivity and resolution of surface-enhanced Raman scattering (SERS) and tip-enhanced Raman spectroscopy (TERS). The strong spatial confinement effect of plasmonic fields has challenged the conventional Raman theory, in which a plane wave approximation for the light has been adopted. In this review, we comprehensively survey the progress of a generalized theory for SERS and TERS in the framework of effective field Hamiltonian (EFH). With this approach, all characteristics of localized plasmonic fields can be well taken into account. By employing EFH, quantitative simulations at the first-principles level for state-of-the-art experimental observations have been achieved, revealing the underlying intrinsic physics in the measurements. The predictive power of EFH is demonstrated by several new phenomena generated from the intrinsic spatial, momentum, time, and energy structures of the localized plasmonic field. The corresponding experimental verifications are also carried out briefly. A comprehensive computational package for modeling of SERS and TERS at the first-principles level is introduced. Finally, we provide an outlook on the future developments of theory and experiments for SERS and TERS.
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Affiliation(s)
- Sai Duan
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai 200433, China.
| | - Guangjun Tian
- State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
| | - Yi Luo
- Hefei National Research Center for Physical Science at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum 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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6
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Li H, Xiang Z, Naik MH, Kim W, Li Z, Sailus R, Banerjee R, Taniguchi T, Watanabe K, Tongay S, Zettl A, da Jornada FH, Louie SG, Crommie MF, Wang F. Imaging moiré excited states with photocurrent tunnelling microscopy. NATURE MATERIALS 2024; 23:633-638. [PMID: 38172545 DOI: 10.1038/s41563-023-01753-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 11/06/2023] [Indexed: 01/05/2024]
Abstract
Moiré superlattices provide a highly tuneable and versatile platform to explore novel quantum phases and exotic excited states ranging from correlated insulators to moiré excitons. Scanning tunnelling microscopy has played a key role in probing microscopic behaviours of the moiré correlated ground states at the atomic scale. However, imaging of quantum excited states in moiré heterostructures remains an outstanding challenge. Here we develop a photocurrent tunnelling microscopy technique that combines laser excitation and scanning tunnelling spectroscopy to directly visualize the electron and hole distribution within the photoexcited moiré exciton in twisted bilayer WS2. The tunnelling photocurrent alternates between positive and negative polarities at different locations within a single moiré unit cell. This alternating photocurrent originates from the in-plane charge transfer moiré exciton in twisted bilayer WS2, predicted by our GW-Bethe-Salpeter equation calculations, that emerges from the competition between the electron-hole Coulomb interaction and the moiré potential landscape. Our technique enables the exploration of photoexcited non-equilibrium moiré phenomena at the atomic scale.
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Affiliation(s)
- Hongyuan Li
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
- Graduate Group in Applied Science and Technology, University of California Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Ziyu Xiang
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
- Graduate Group in Applied Science and Technology, University of California Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Mit H Naik
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Woochang Kim
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Zhenglu Li
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Renee Sailus
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA
| | - Rounak Banerjee
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Sefaattin Tongay
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA
| | - Alex Zettl
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Kavli Energy Nano Sciences Institute, University of California Berkeley and Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Felipe H da Jornada
- Department of Materials Science and Engineering, Stanford University, Palo Alto, CA, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Steven G Louie
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - Michael F Crommie
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Kavli Energy Nano Sciences Institute, University of California Berkeley and Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - Feng Wang
- Department of Physics, University of California at Berkeley, Berkeley, CA, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Kavli Energy Nano Sciences Institute, University of California Berkeley and Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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7
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Zhang X, Li Z, Ji S, Xu W, Chen L, Xiao Z, Liu J, Hong W. Plasmon-Molecule Interactions in Single-Molecule Junctions. Chempluschem 2024; 89:e202300556. [PMID: 38050755 DOI: 10.1002/cplu.202300556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 11/16/2023] [Accepted: 11/28/2023] [Indexed: 12/06/2023]
Abstract
Single-molecule optoelectronics offers opportunities for advancing integrated photonics and electronics, which also serves as a tool to elucidate the underlying mechanism of light-matter interaction. Plasmonics, which plays pivotal role in the interaction of photons and matter, have became an emerging area. A comprehensive understanding of the plasmonic excitation and modulation mechanisms within single-molecule junctions (SMJs) lays the foundation for optoelectronic devices. Consequently, this review primarily concentrates on illuminating the fundamental principles of plasmonics within SMJs, delving into their research methods and modulation factors of plasmon-exciton. Moreover, we underscore the interaction phenomena within SMJs, including the enhancement of molecular fluorescence by plasmonics, Fano resonance and Rabi splitting caused by the interaction of plasmon-exciton. Finally, by emphasizing the potential applications of plasmonics within SMJs, such as their roles in optical tweezers, single-photon sources, super-resolution imaging, and chemical reactions, we elucidate the future prospects and current challenges in this domain.
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Affiliation(s)
- Xiangui Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian, 361005, China
| | - Zhengyu Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian, 361005, China
| | - Shurui Ji
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian, 361005, China
| | - Wei Xu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian, 361005, China
| | - Lijue Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian, 361005, China
| | - Zongyuan Xiao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian, 361005, China
| | - Junyang Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian, 361005, China
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian, 361005, China
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8
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Hung TC, Godinez-Loyola Y, Steinbrecher M, Kiraly B, Khajetoorians AA, Doltsinis NL, Strassert CA, Wegner D. Activating the Fluorescence of a Ni(II) Complex by Energy Transfer. J Am Chem Soc 2024; 146:8858-8864. [PMID: 38513215 PMCID: PMC10996004 DOI: 10.1021/jacs.3c07716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 03/07/2024] [Accepted: 03/07/2024] [Indexed: 03/23/2024]
Abstract
Luminescence of open-shell 3d metal complexes is often quenched due to ultrafast intersystem crossing (ISC) and cooling into a dark metal-centered excited state. We demonstrate successful activation of fluorescence from individual nickel phthalocyanine (NiPc) molecules in the junction of a scanning tunneling microscope (STM) by resonant energy transfer from other metal phthalocyanines at low temperature. By combining STM, scanning tunneling spectroscopy, STM-induced luminescence, and photoluminescence experiments as well as time-dependent density functional theory, we provide evidence that there is an activation barrier for the ISC, which, in most experimental conditions, is overcome. We show that this is also the case in an electroluminescent tunnel junction where individual NiPc molecules adsorbed on an ultrathin NaCl decoupling film on a Ag(111) substrate are probed. However, when an MPc (M = Zn, Pd, Pt) molecule is placed close to NiPc by means of STM atomic manipulation, resonant energy transfer can excite NiPc without overcoming the ISC activation barrier, leading to Q-band fluorescence. This work demonstrates that the thermally activated population of dark metal-centered states can be avoided by a designed local environment at low temperatures paired with directed molecular excitation into vibrationally cold electronic states. Thus, we can envisage the use of luminophores based on more abundant transition metal complexes that do not rely on Pt or Ir by restricting vibration-induced ISC.
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Affiliation(s)
- Tzu-Chao Hung
- Institute
for Molecules and Materials, Radboud University, 6500 GL Nijmegen, The Netherlands
- Institute
for Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Yokari Godinez-Loyola
- Institut
für Anorganische und Analytische Chemie, University of Münster, 48149 Münster, Germany
- Center
for Nanotechnology (CeNTech), University
of Münster, 48149 Münster, Germany
| | - Manuel Steinbrecher
- Institute
for Molecules and Materials, Radboud University, 6500 GL Nijmegen, The Netherlands
| | - Brian Kiraly
- Institute
for Molecules and Materials, Radboud University, 6500 GL Nijmegen, The Netherlands
| | | | - Nikos L. Doltsinis
- Institut
für Festkörpertheorie and Center for Multiscale Theory
and Computation, University of Münster, 48149 Münster, Germany
| | - Cristian A. Strassert
- Institut
für Anorganische und Analytische Chemie, University of Münster, 48149 Münster, Germany
- Center
for Nanotechnology (CeNTech), University
of Münster, 48149 Münster, Germany
- Cells in
Motion Interfaculty Centre (CiMIC) and Center for Soft Nanoscience
(SoN), University of Münster, 48149 Münster, Germany
| | - Daniel Wegner
- Institute
for Molecules and Materials, Radboud University, 6500 GL Nijmegen, The Netherlands
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9
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Luo Y, Kong FF, Tian XJ, Yu YJ, Jing SH, Zhang C, Chen G, Zhang Y, Zhang Y, Li XG, Zhang ZY, Dong ZC. Anomalously bright single-molecule upconversion electroluminescence. Nat Commun 2024; 15:1677. [PMID: 38395971 PMCID: PMC10891098 DOI: 10.1038/s41467-024-45450-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 01/23/2024] [Indexed: 02/25/2024] Open
Abstract
Efficient upconversion electroluminescence is highly desirable for a broad range of optoelectronic applications, yet to date, it has been reported only for ensemble systems, while the upconversion electroluminescence efficiency remains very low for single-molecule emitters. Here we report on the observation of anomalously bright single-molecule upconversion electroluminescence, with emission efficiencies improved by more than one order of magnitude over previous studies, and even stronger than normal-bias electroluminescence. Intuitively, the improvement is achieved via engineering the energy-level alignments at the molecule-substrate interface so as to activate an efficient spin-triplet mediated upconversion electroluminescence mechanism that only involves pure carrier injection steps. We further validate the intuitive picture with the construction of delicate electroluminescence diagrams for the excitation of single-molecule electroluminescence, allowing to readily identify the prerequisite conditions for producing efficient upconversion electroluminescence. These findings provide deep insights into the microscopic mechanism of single-molecule upconversion electroluminescence and organic electroluminescence in general.
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Affiliation(s)
- Yang Luo
- International Center for Quantum Design of Functional Materials (ICQD), 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
| | - Fan-Fang Kong
- International Center for Quantum Design of Functional Materials (ICQD), 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-Jun Tian
- International Center for Quantum Design of Functional Materials (ICQD), 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
| | - Yun-Jie Yu
- International Center for Quantum Design of Functional Materials (ICQD), 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
| | - Shi-Hao Jing
- International Center for Quantum Design of Functional Materials (ICQD), 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
| | - Chao Zhang
- International Center for Quantum Design of Functional Materials (ICQD), 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
- International Center for Quantum Design of Functional Materials (ICQD), 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
- International Center for Quantum Design of Functional Materials (ICQD), 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
- International Center for Quantum Design of Functional Materials (ICQD), 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
| | - Xiao-Guang Li
- Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Zhen-Yu Zhang
- International Center for Quantum Design of Functional Materials (ICQD), 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
- International Center for Quantum Design of Functional Materials (ICQD), 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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10
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Coane CV, Romanelli M, Dall'Osto G, Di Felice R, Corni S. Unraveling the mechanism of tip-enhanced molecular energy transfer. Commun Chem 2024; 7:32. [PMID: 38360897 PMCID: PMC10869822 DOI: 10.1038/s42004-024-01118-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 02/01/2024] [Indexed: 02/17/2024] Open
Abstract
Electronic Energy Transfer (EET) between chromophores is fundamental in many natural light-harvesting complexes, serving as a critical step for solar energy funneling in photosynthetic plants and bacteria. The complicated role of the environment in mediating this process in natural architectures has been addressed by recent scanning tunneling microscope experiments involving EET between two molecules supported on a solid substrate. These measurements demonstrated that EET in such conditions has peculiar features, such as a steep dependence on the donor-acceptor distance, reminiscent of a short-range mechanism more than of a Förster-like process. By using state of the art hybrid ab initio/electromagnetic modeling, here we provide a comprehensive theoretical analysis of tip-enhanced EET. In particular, we show that this process can be understood as a complex interplay of electromagnetic-based molecular plasmonic processes, whose result may effectively mimic short range effects. Therefore, the established identification of an exponential decay with Dexter-like effects does not hold for tip-enhanced EET, and accurate electromagnetic modeling is needed to identify the EET mechanism.
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Affiliation(s)
- Colin V Coane
- Department of Chemical Sciences, University of Padova, via Marzolo 1, Padova, Italy
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, 90089, USA
| | - Marco Romanelli
- Department of Chemical Sciences, University of Padova, via Marzolo 1, Padova, Italy
| | - Giulia Dall'Osto
- Department of Chemical Sciences, University of Padova, via Marzolo 1, Padova, Italy
| | - Rosa Di Felice
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, 90089, USA.
- CNR Institute of Nanoscience, via Campi 213/A, Modena, Italy.
| | - Stefano Corni
- Department of Chemical Sciences, University of Padova, via Marzolo 1, Padova, Italy.
- CNR Institute of Nanoscience, via Campi 213/A, Modena, Italy.
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11
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Maytin A, Gruebele M. High index dielectric films on metals: An island of emission. J Chem Phys 2024; 160:014704. [PMID: 38168695 DOI: 10.1063/5.0181874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 12/11/2023] [Indexed: 01/05/2024] Open
Abstract
Fluorescent emitters are quenched near the surfaces of metals via rapid energy transfer to the metal, via surface plasmons, waveguide modes, and absorption. Commonly, this quenching is reduced by introducing a polymeric or dielectric spacer but requires large distances, at least a fraction of the wavelength, between the metal and chromophore. Using the classical theory for a dipole above a metal/dielectric substrate, we investigate the fluorescent yield for emitters above a wide range of metals and spacers. For metals with low loss and low plasma frequencies, a high index spacer is shown to be advantageous for obtaining higher fluorescent yield in an "island of emission" at finely tuned spacer thickness just 20-30 nm from the metal surface. For such metal-dielectric combinations, fluorophores can be placed surprisingly close to the metal surface while remaining significantly emissive.
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Affiliation(s)
- Andrew Maytin
- Department of Physics, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA
| | - Martin Gruebele
- Department of Physics, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA
- Department of Chemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA
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12
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Yonemoto R, Ueda R, Otomo A, Noguchi Y. Light-Emitting Electrochemical Cells Based on Nanogap Electrodes. NANO LETTERS 2023; 23:7493-7499. [PMID: 37579029 DOI: 10.1021/acs.nanolett.3c02001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Abstract
In a light-emitting electrochemical cell (LEC), electrochemical doping caused by mobile ions facilitates bipolar charge injection and recombination emissions for a high electroluminescence (EL) intensity at low driving voltages. We present the development of a nanogap LEC (i.e., nano-LEC) comprising a light-emitting polymer (F8BT) and an ionic liquid deposited on a gold nanogap electrode. The device demonstrated a high EL intensity at a wavelength of 540 nm corresponding to the emission peak of F8BT and a threshold voltage of ∼2 V at 300 K. Upon application of a constant voltage, the device demonstrated a gradual increase in current intensity followed by light emission. Notably, the delayed components of the current and EL were strongly suppressed at low temperatures (<285 K). The results clearly indicate that the device functions as an LEC and that the nano-LEC is a promising approach to realizing molecular-scale current-induced light sources.
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Affiliation(s)
- Ryo Yonemoto
- Graduate School of Science and Technology, Meiji University, Kawasaki 214-8571, Japan
| | - Rieko Ueda
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Akira Otomo
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe 651-2492, Japan
| | - Yutaka Noguchi
- Graduate School of Science and Technology, Meiji University, Kawasaki 214-8571, Japan
- School of Science & Technology, Meiji University, Kawasaki 214-8571, Japan
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13
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Kaiser K, Lieske LA, Repp J, Gross L. Charge-state lifetimes of single molecules on few monolayers of NaCl. Nat Commun 2023; 14:4988. [PMID: 37591847 PMCID: PMC10435478 DOI: 10.1038/s41467-023-40692-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 08/02/2023] [Indexed: 08/19/2023] Open
Abstract
In molecular tunnel junctions, where the molecule is decoupled from the electrodes by few-monolayers-thin insulating layers, resonant charge transport takes place by sequential charge transfer to and from the molecule which implies transient charging of the molecule. The corresponding charge state transitions, which involve tunneling through the insulating decoupling layers, are crucial for understanding electrically driven processes such as electroluminescence or photocurrent generation in such a geometry. Here, we use scanning tunneling microscopy to investigate the decharging of single ZnPc and H2Pc molecules through NaCl films of 3 to 5 monolayers thickness on Cu(111) and Au(111). To this end, we approach the tip to the molecule at resonant tunnel conditions up to a regime where charge transport is limited by tunneling through the NaCl film. The resulting saturation of the tunnel current is a direct measure of the lifetimes of the anionic and cationic states, i.e., the molecule's charge-state lifetime, and thus provides a means to study charge dynamics and, thereby, exciton dynamics. Comparison of anion and cation lifetimes on different substrates reveals the critical role of the level alignment with the insulator's conduction and valence band, and the metal-insulator interface state.
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Affiliation(s)
- Katharina Kaiser
- IBM Research Europe-Zurich, Säumerstrasse 4, 8803, Rüschlikon, Switzerland.
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000, Strasbourg, France.
| | | | - Jascha Repp
- Department of Physics, University of Regensburg, Universitätsstraße 31, 93053, Regensburg, Germany
| | - Leo Gross
- IBM Research Europe-Zurich, Säumerstrasse 4, 8803, Rüschlikon, Switzerland.
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14
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Duan S, Xu X. Accurate Simulations of Scanning Tunneling Microscope: Both Tip and Substrate States Matter. J Phys Chem Lett 2023:6726-6735. [PMID: 37470339 DOI: 10.1021/acs.jpclett.3c01603] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
Scanning tunneling microscope (STM) provides an atomic-scale characterization tool. To this end, high-resolution measurements and accurate simulations must closely cooperate. Emerging experimental techniques, e.g., substrate spacers and tip modifications, suppress metallic couplings and improve the resolution. On the other hand, development of STM simulation methods was inactive in the past decade. Conventional simulations focus on the electronic structure of the substrate, often overlooking detailed descriptions of the tip states. Meanwhile, the overwhelming usage of periodic boundary conditions ensures effective simulations of only neutral systems. In this Perspective, we highlight the recent progress that takes the effects of both tip and substrate into account under either Tersoff-Hamann or Bardeen's approximation, which provides an accurate analysis of measured high-resolution STM results, uncovers underlying concepts, and rationally designs experimental protocols for important chemical systems. We hope this Perspective will stimulate broad interest in advanced STM simulations, highlighting the way forward for STM investigations that involve complex geometrical and electronic structures.
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Affiliation(s)
- Sai Duan
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China
| | - Xin Xu
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China
- Hefei National Laboratory, Hefei 230088, P. R. China
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15
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Grewal A, Leon CC, Kuhnke K, Kern K, Gunnarsson O. Character of Electronic States in the Transport Gap of Molecules on Surfaces. ACS NANO 2023. [PMID: 37387521 PMCID: PMC10373518 DOI: 10.1021/acsnano.2c12447] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Abstract
We report on scanning tunneling microscopy (STM) topographs of individual metal phthalocyanines (MPc) on a thin salt (NaCl) film adsorbed on a gold substrate, at tunneling energies within the molecule's electronic transport gap. Theoretical models of increasing complexity are discussed. The calculations for MPcs adsorbed on a thin NaCl layer on Au(111) demonstrate that the STM pattern rotates with the molecule's orientations─in excellent agreement with the experimental data. Thus, even the STM topography obtained for energies in the transport gap represent the structure of a one atom thick molecule. It is shown that the electronic states inside the transport gap can be rather accurately approximated by linear combinations of bound molecular orbitals (MOs). The gap states include not only the frontier orbitals but also surprisingly large contributions from energetically much lower MOs. These results will be essential for understanding processes, such as exciton creation, which can be induced by electrons tunneling through the transport gap of a molecule.
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Affiliation(s)
- Abhishek Grewal
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Christopher C Leon
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Klaus Kuhnke
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Klaus Kern
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
- Institut de Physique, École Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Olle Gunnarsson
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
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16
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Yu YJ, Kuai Y, Fan YT, Zhu LF, Kong FF, Tian XJ, Jing SH, Zhang L, Zhang DG, Zhang Y, Zhang Y, Dong ZC. Back focal plane imaging for light emission from a tunneling junction in a low-temperature ultrahigh-vacuum scanning tunneling microscope. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:063703. [PMID: 37862523 DOI: 10.1063/5.0147401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/04/2023] [Indexed: 10/22/2023]
Abstract
We report the design and realization of the back focal plane (BFP) imaging for the light emission from a tunnel junction in a low-temperature ultrahigh-vacuum (UHV) scanning tunneling microscope (STM). To achieve the BFP imaging in a UHV environment, a compact "all-in-one" sample holder is designed and fabricated, which allows us to integrate the sample substrate with the photon collection units that include a hemisphere solid immersion lens and an aspherical collecting lens. Such a specially designed holder enables the characterization of light emission both within and beyond the critical angle and also facilitates the optical alignment inside a UHV chamber. To test the performance of the BFP imaging system, we first measure the photoluminescence from dye-doped polystyrene beads on a thin Ag film. A double-ring pattern is observed in the BFP image, arising from two kinds of emission channels: strong surface plasmon coupled emissions around the surface plasmon resonance angle and weak transmitted fluorescence maximized at the critical angle, respectively. Such an observation also helps to determine the emission angle for each image pixel in the BFP image and, more importantly, proves the feasibility of our BFP imaging system. Furthermore, as a proof-of-principle experiment, electrically driven plasmon emissions are used to demonstrate the capability of the constructed BFP imaging system for STM induced electroluminescence measurements. A single-ring pattern is obtained in the BFP image, which reveals the generation and detection of the leakage radiation from the surface plasmon propagating on the Ag surface. Further analyses of the BFP image provide valuable information on the emission angle of the leakage radiation, the orientation of the radiating dipole, and the plasmon wavevector. The UHV-BFP imaging technique demonstrated here opens new routes for future studies on the angular distributed emission and dipole orientation of individual quantum emitters in UHV.
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Affiliation(s)
- Yun-Jie Yu
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230088, China
| | - Yan Kuai
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yong-Tao Fan
- Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Liang-Fu Zhu
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Fan-Fang Kong
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiao-Jun Tian
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Shi-Hao Jing
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Li Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Dou-Guo Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230088, China
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yao Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230088, China
- School of Physics and Department of Chemical 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 Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230088, China
- School of Physics and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhen-Chao Dong
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230088, China
- School of Physics and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
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17
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Huang L. Tunnelling electrons locally ignite excitons. NATURE MATERIALS 2023; 22:414-415. [PMID: 37002499 DOI: 10.1038/s41563-023-01514-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Affiliation(s)
- Libai Huang
- Department of Chemistry, Purdue University, West Lafayette, IN, USA.
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18
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Yang C, Guo Y, Zhou S, Liu Z, Liu Z, Zhang D, Guo X. A Tunable Single-Molecule Light-Emitting Diode with Single-Photon Precision. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2209750. [PMID: 36718825 DOI: 10.1002/adma.202209750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 01/01/2023] [Indexed: 06/18/2023]
Abstract
A robust single-molecule light-emitting diode (SM-LED) with high color purity, linear polarization, and efficiency tunability is prepared by covalently integrating one fluorescent molecule into nanogapped graphene electrodes. Furthermore, single-molecule Förster resonance energy transfer from the electroluminescent center to different accepters is achieved through rational molecular engineering, enabling construction of a multicolor SM-LED. All these characterizations are accomplished in the photoelectrical integration system with high temporal/spatial/energy resolution, demonstrating the capability of the single-photon emission of SM-LEDs. The success in developing high-performance SM-LEDs inspires the development of the next generation of commercial display devices and promises a single-photon emitter for use in quantum computation and quantum communication.
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Affiliation(s)
- Chen Yang
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing, 100871, P. R. China
| | - Yilin Guo
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing, 100871, P. R. China
| | - Shuyao Zhou
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing, 100871, P. R. China
| | - Zhirong Liu
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing, 100871, P. R. China
| | - Zitong Liu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, P. R. China
| | - Deqing Zhang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Xuefeng Guo
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing, 100871, P. R. China
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin, 300350, P. R. China
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19
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López LEP, Rosławska A, Scheurer F, Berciaud S, Schull G. Tip-induced excitonic luminescence nanoscopy of an atomically resolved van der Waals heterostructure. NATURE MATERIALS 2023; 22:482-488. [PMID: 36928383 DOI: 10.1038/s41563-023-01494-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
The electronic and optical properties of van der Waals heterostructures are strongly influenced by the structuration and homogeneity of their nano- and atomic-scale environments. Unravelling this intimate structure-property relationship is a key challenge that requires methods capable of addressing the light-matter interactions in van der Waals materials with ultimate spatial resolution. Here we use a low-temperature scanning tunnelling microscope to probe-with atomic-scale resolution-the excitonic luminescence of a van der Waals heterostructure, made of a transition metal dichalcogenide monolayer stacked onto a few-layer graphene flake supported by a Au(111) substrate. Sharp emission lines arising from neutral, charged and localized excitons are reported. Their intensities and emission energies vary as a function of the nanoscale topography of the van der Waals heterostructure, explaining the variability of the emission properties observed with diffraction-limited approaches. Our work paves the way towards understanding and controlling optoelectronic phenomena in moiré superlattices with atomic-scale resolution.
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Affiliation(s)
- Luis E Parra López
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, Strasbourg, France
| | - Anna Rosławska
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, Strasbourg, France
| | - Fabrice Scheurer
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, Strasbourg, France
| | - Stéphane Berciaud
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, Strasbourg, France.
| | - Guillaume Schull
- Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg, UMR 7504, Strasbourg, France.
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20
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Jiang S, Neuman T, Bretel R, Boeglin A, Scheurer F, Le Moal E, Schull G. Many-Body Description of STM-Induced Fluorescence of Charged Molecules. PHYSICAL REVIEW LETTERS 2023; 130:126202. [PMID: 37027885 DOI: 10.1103/physrevlett.130.126202] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 01/30/2023] [Indexed: 06/19/2023]
Abstract
A scanning tunneling microscope is used to study the fluorescence of a model charged molecule (quinacridone) adsorbed on a sodium chloride (NaCl)-covered metallic sample. Fluorescence from the neutral and positively charged species is reported and imaged using hyperresolved fluorescence microscopy. A many-body model is established based on a detailed analysis of voltage, current, and spatial dependences of the fluorescence and electron transport features. This model reveals that quinacridone adopts a palette of charge states, transient or not, depending on the voltage used and the nature of the underlying substrate. This model has a universal character and clarifies the transport and fluorescence mechanisms of molecules adsorbed on thin insulators.
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Affiliation(s)
- Song Jiang
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Tomáš Neuman
- Institut des Sciences Moléculaires d'Orsay (ISMO), UMR 8214, CNRS, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Rémi Bretel
- Institut des Sciences Moléculaires d'Orsay (ISMO), UMR 8214, CNRS, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Alex Boeglin
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Fabrice Scheurer
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Eric Le Moal
- Institut des Sciences Moléculaires d'Orsay (ISMO), UMR 8214, CNRS, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Guillaume Schull
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
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21
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Wu X, Néel N, Brandbyge M, Kröger J. Enhancement of Graphene Phonon Excitation by a Chemically Engineered Molecular Resonance. PHYSICAL REVIEW LETTERS 2023; 130:116201. [PMID: 37001107 DOI: 10.1103/physrevlett.130.116201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 02/21/2023] [Indexed: 06/19/2023]
Abstract
The abstraction of pyrrolic hydrogen from a single phthalocyanine on graphene turns the molecule into a sensitive probe for graphene phonons. The inelastic electron transport measured with a scanning tunneling microscope across the molecular adsorbate and graphene becomes strongly enhanced for a graphene out-of-plane acoustic phonon mode. Supporting density functional and transport calculations elucidate the underlying physical mechanism. A molecular orbital resonance close to the Fermi energy controls the inelastic current while specific phonon modes of graphene are magnified due to their coupling to symmetry-equivalent vibrational quanta of the molecule.
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Affiliation(s)
- Xiaocui Wu
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
| | - Nicolas Néel
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
| | - Mads Brandbyge
- Center of Nanostructured Graphene, Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Jörg Kröger
- Institut für Physik, Technische Universität Ilmenau, D-98693 Ilmenau, Germany
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22
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Amini M, Silveira OJ, Vaňo V, Lado JL, Foster AS, Liljeroth P, Kezilebieke S. Control of Molecular Orbital Ordering Using a van der Waals Monolayer Ferroelectric. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2206456. [PMID: 36526444 DOI: 10.1002/adma.202206456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 12/08/2022] [Indexed: 06/17/2023]
Abstract
2D ferroelectric materials provide a promising platform for the electrical control of quantum states. In particular, due to their 2D nature, they are suitable for influencing the quantum states of deposited molecules via the proximity effect. Here, electrically controllable molecular states in phthalocyanine molecules adsorbed on monolayer ferroelectric material SnTe are reported. The strain and ferroelectric order in SnTe are found to create a transition between two distinct orbital orders in the adsorbed phthalocyanine molecules. By controlling the polarization of the ferroelectric domain using scanning tunneling microscopy (STM), it is successfully demonstrated that orbital order can be manipulated electrically. The results show how ferroelastic coupling in 2D systems allows for control of molecular states, providing a starting point for ferroelectrically switchable molecular orbital ordering and ultimately, electrical control of molecular magnetism.
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Affiliation(s)
- Mohammad Amini
- Department of Applied Physics, Aalto University, Aalto, FI-00076, Finland
| | - Orlando J Silveira
- Department of Applied Physics, Aalto University, Aalto, FI-00076, Finland
| | - Viliam Vaňo
- Department of Applied Physics, Aalto University, Aalto, FI-00076, Finland
| | - Jose L Lado
- Department of Applied Physics, Aalto University, Aalto, FI-00076, Finland
| | - Adam S Foster
- Department of Applied Physics, Aalto University, Aalto, FI-00076, Finland
- WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan
| | - Peter Liljeroth
- Department of Applied Physics, Aalto University, Aalto, FI-00076, Finland
| | - Shawulienu Kezilebieke
- Department of Physics, Department of Chemistry and Nanoscience Center, University of Jyväskylä, Jyväskylä, FI-40014, Finland
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23
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Xiao J, Zhao W, Li L, Ma L, Tian G. Adsorption properties of a paracyclophane molecule on NaCl/Au surfaces: a first-principles study. Phys Chem Chem Phys 2023; 25:6060-6066. [PMID: 36751852 DOI: 10.1039/d2cp04745d] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Ultrathin insulating layers are commonly applied in scanning tunneling microscope (STM) measurements on molecular systems to preserve the intrinsic properties of a sample. We examine in the present work the adsorption properties of a double-decker 3,3-paracyclophane (PCP) molecule supported on Au surfaces with thin NaCl monolayers (MLs) as the decoupling spacer by using first-principles calculations. The interactions between the adsorbed molecule and the substrate were analyzed in terms of the adsorption energy, dispersion interactions, charge transfer, and molecular structure changes. The simulation results show that the presence of NaCl can significantly reduce the adsorption energy as well as the charge transfer between the molecule and the substrate. Detailed analysis of the differential charge density and partial charge density of states indicates that three MLs of NaCl are sufficient to decouple the molecule from the Au substrate with no significant changes in the adsorption properties of the PCP with the further increase of the thickness of the NaCl spacer. These results could be helpful for the application of the interesting double-decker molecules as functional single-molecule devices where the intrinsic molecular properties need to be preserved.
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Affiliation(s)
- Jiyin Xiao
- State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao, 066004, P. R. China.
| | - Wenjing Zhao
- State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao, 066004, P. R. China.
| | - Li Li
- State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao, 066004, P. R. China.
| | - Liang Ma
- State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao, 066004, P. R. China.
| | - Guangjun Tian
- State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao, 066004, P. R. China.
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24
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Duan S, Tian G, Xu X. A General Framework of Scanning Tunneling Microscopy Based on Bardeen's Approximation for Isolated Molecules. JACS AU 2023; 3:86-92. [PMID: 36711086 PMCID: PMC9875243 DOI: 10.1021/jacsau.2c00627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/18/2022] [Accepted: 12/28/2022] [Indexed: 06/18/2023]
Abstract
Scanning tunneling microscopy (STM) is one of the most popular techniques for precise characterization. Yet, its current theoretical implementation is often based on the periodic boundary condition with the Tersoff-Hamann approximation, which is inefficient to explore the tip states other than the s-wave and to treat properly the charged molecules that are ubiquitous in chemistry. In this work, we establish a general theoretical framework for STM image simulations, which is based on the Bardeen's approximation and utilizes the boundary condition of the cluster model. We develop an analytic algorithm for the precise evaluation of the transfer Hamiltonian matrix, addressing correctly the asymptotic behaviors of the tip states. Numerical results demonstrate that the molecular images under different STM tip states and mapping modes can be quantitatively simulated in the present framework, which paves the avenue for the conclusive investigation of the ground state electronic structures for either neutral or charged molecules.
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Affiliation(s)
- Sai Duan
- Collaborative
Innovation Center of Chemistry for Energy Materials, Shanghai Key
Laboratory of Molecular Catalysis and Innovative Materials, MOE Key
Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai200433, P. R. China
| | - Guangjun Tian
- Key
Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao, 066004, P. R. China
| | - Xin Xu
- Collaborative
Innovation Center of Chemistry for Energy Materials, Shanghai Key
Laboratory of Molecular Catalysis and Innovative Materials, MOE Key
Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai200433, P. R. China
- Hefei
National Laboratory, Hefei230088, P. R. China
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25
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Rai V, Gerhard L, Balzer N, Valášek M, Holzer C, Yang L, Wegener M, Rockstuhl C, Mayor M, Wulfhekel W. Activating Electroluminescence of Charged Naphthalene Diimide Complexes Directly Adsorbed on a Metal Substrate. PHYSICAL REVIEW LETTERS 2023; 130:036201. [PMID: 36763403 DOI: 10.1103/physrevlett.130.036201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 09/02/2022] [Accepted: 12/13/2022] [Indexed: 06/18/2023]
Abstract
Electroluminescence from single molecules adsorbed on a conducting surface imposes conflicting demands for the molecule-electrode coupling. To conduct electrons, the molecular orbitals need to be hybridized with the electrodes. To emit light, they need to be decoupled from the electrodes to prevent fluorescence quenching. Here, we show that fully quenched 2,6-core-substituted naphthalene diimide derivative in a self-assembled monolayer directly deposited on a Au(111) surface can be activated with the tip of a scanning tunneling microscope to decouple the relevant frontier orbitals from the metallic substrate. In this way, individual molecules can be driven from a strongly hybridized state with quenched luminescence to a light-emitting state. The emission performance compares in terms of quantum efficiency, stability, and reproducibility to that of single molecules deposited on thin insulating layers. Quantum chemical calculations suggest that the emitted light originates from the singly charged cationic pair of the molecules.
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Affiliation(s)
- Vibhuti Rai
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
| | - Lukas Gerhard
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
| | - Nico Balzer
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
| | - Michal Valášek
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
| | - Christof Holzer
- Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology (KIT), D-76128 Karlsruhe, Germany
| | - Liang Yang
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), D-76128 Karlsruhe, Germany
| | - Martin Wegener
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), D-76128 Karlsruhe, Germany
| | - Carsten Rockstuhl
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
- Institute of Theoretical Solid State Physics, Karlsruhe Institute of Technology (KIT), D-76128 Karlsruhe, Germany
| | - Marcel Mayor
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
- Department of Chemistry, University of Basel, St. Johannsring 19, CH-4056 Basel, Switzerland
- Lehn Institute of Functional Materials (LIFM), Sun Yat-Sen University (SYSU), Xingang West Road, Guangzhou, China
| | - Wulf Wulfhekel
- Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen, Germany
- Physikalisches Institut, Karlsruhe Institute of Technology (KIT), D-76128 Karlsruhe, Germany
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26
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Li E, Lyu CK, Chen C, Xie H, Zhang J, Lam JWY, Tang BZ, Lin N. On-surface synthesis and spontaneous segregation of conjugated tetraphenylethylene macrocycles. Commun Chem 2022; 5:174. [PMID: 36697742 PMCID: PMC9814618 DOI: 10.1038/s42004-022-00794-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 12/07/2022] [Indexed: 12/24/2022] Open
Abstract
Creating conjugated macrocycles has attracted extensive research interest because their unique chemical and physical properties, such as conformational flexibility, intrinsic inner cavities and aromaticity/antiaromaticity, make these systems appealing building blocks for functional supramolecular materials. Here, we report the synthesis of four-, six- and eight-membered tetraphenylethylene (TPE)-based macrocycles on Ag(111) via on-surface Ullmann coupling reactions. The as-synthesized macrocycles are spontaneously segregated on the surface and self-assemble as large-area two-dimensional mono-component supramolecular crystals, as characterized by scanning tunneling microscopy (STM). We propose that the synthesis benefits from the conformational flexibility of the TPE backbone in distinctive multi-step reaction pathways. This study opens up opportunities for exploring the photophysical properties of TPE-based macrocycles.
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Affiliation(s)
- En Li
- grid.24515.370000 0004 1937 1450Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Cheng-Kun Lyu
- grid.24515.370000 0004 1937 1450Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Chengyi Chen
- grid.24515.370000 0004 1937 1450Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Huilin Xie
- grid.24515.370000 0004 1937 1450Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Jianyu Zhang
- grid.24515.370000 0004 1937 1450Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Jacky Wing Yip Lam
- grid.24515.370000 0004 1937 1450Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Ben Zhong Tang
- grid.24515.370000 0004 1937 1450Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China ,grid.10784.3a0000 0004 1937 0482School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen, Guangdong China
| | - Nian Lin
- grid.24515.370000 0004 1937 1450Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
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27
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Nian LL, Wang T, Lü JT. Plasmon Squeezing in Single-Molecule Junctions. NANO LETTERS 2022; 22:9418-9423. [PMID: 36449564 DOI: 10.1021/acs.nanolett.2c03371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Scanning tunneling microscope (STM)-induced luminescence provides an ideal platform for electrical generation and the atomic-scale manipulation of nonclassical states of light. However, despite its extreme importance in quantum technologies, squeezed light emission with reduced quantum fluctuations has hitherto not been demonstrated in such a platform. Here, we theoretically predict that the emitted light from the plasmon mode can be squeezed in an STM single molecular junction subject to an external laser drive. Going beyond the traditional paradigm that generates squeezing with the quadratic interaction of photons, our prediction explores the molecular coherence involved in an anharmonic energy spectrum of a coupled plasmon-molecule-exciton system. Furthermore, we show that, by selectively exciting the energy ladder, the squeezed plasmon can show either sub- or super-Poissonian statistical properties. We also demonstrate that, following the same principle, the molecular excitonic mode can be squeezed simultaneously.
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Affiliation(s)
- Lei-Lei Nian
- School of Physics and Astronomy, Yunnan University, 650091Kunming, People's Republic of China
| | - Tao Wang
- School of Physics, Institute for Quantum Science and Engineering, and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074Wuhan, People's Republic of China
| | - Jing-Tao Lü
- School of Physics, Institute for Quantum Science and Engineering, and Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, 430074Wuhan, People's Republic of China
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28
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Martín-Jiménez A, Jover Ó, Lauwaet K, Granados D, Miranda R, Otero R. Selectively Addressing Plasmonic Modes and Excitonic States in a Nanocavity Hosting a Quantum Emitter. NANO LETTERS 2022; 22:9283-9289. [PMID: 36441511 PMCID: PMC9756330 DOI: 10.1021/acs.nanolett.2c02758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 11/18/2022] [Indexed: 06/16/2023]
Abstract
Controlling the interaction between the excitonic states of a quantum emitter and the plasmonic modes of a nanocavity is key for the development of quantum information processing devices. In this Letter we demonstrate that the tunnel electroluminescence of electrically insulated C60 nanocrystals enclosed in the plasmonic nanocavity at the junction of a scanning tunneling microscope can be switched from a broad emission spectrum, revealing the plasmonic modes of the cavity, to a narrow band emission, displaying only the excitonic states of the C60 molecules by changing the bias voltage applied to the junction. Interestingly, excitonic emission dominates the spectra in the high-voltage region in which the simultaneously acquired inelastic rate is low, demonstrating that the excitons cannot be created by an inelastic tunnel process. These results point toward new possible mechanisms for tunnel electroluminescence of quantum emitters and offer new avenues to develop electrically tunable nanoscale light sources.
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Affiliation(s)
| | - Óscar Jover
- IMDEA-Nanoscience
Center, 28049Madrid, Spain
- Departamento
de Física de la Materia Condensada & IFIMAC, Universidad Autónoma de Madrid, 28049Madrid, Spain
| | | | | | - Rodolfo Miranda
- IMDEA-Nanoscience
Center, 28049Madrid, Spain
- Departamento
de Física de la Materia Condensada & IFIMAC, Universidad Autónoma de Madrid, 28049Madrid, Spain
| | - Roberto Otero
- IMDEA-Nanoscience
Center, 28049Madrid, Spain
- Departamento
de Física de la Materia Condensada & IFIMAC, Universidad Autónoma de Madrid, 28049Madrid, Spain
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29
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Krukowski P, Hattori T, Akai-Kasaya M, Saito A, Osuga H, Kuwahara Y. Light Emission from M-Type Enantiomer of 2,13-bis(hydroxymethyl)[7]-thiaheterohelicene Molecules Adsorbed on Au(111) and C 60/Au(111) Surfaces Investigated by STM-LE. Int J Mol Sci 2022; 23:ijms232315399. [PMID: 36499724 PMCID: PMC9737099 DOI: 10.3390/ijms232315399] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/26/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Light emission from the M-type enantiomer of a helicene derivative (2,13-bis(hydroxymethyl)[7]-thiaheterohelicene) adsorbed on the clean Au(111) and the C60-covered Au(111) surfaces were investigated by tunneling-current-induced light-emission technique. Plasmon-originated light emission was observed on the helicence/Au(111) surface and it was strongly suppressed on the area where the helicene molecules were adsorbed at the edges of the Au(111) terraces. To avoid luminescence quenching of excited helicene molecules and to suppress strong plasmon light emission from the Au(111) surface, C60 layers were used as decoupling buffer layers between helicene molecules and the Au(111) surface. Helicene molecules were adsorbed preferentially on the Au(111) surface rather than on the C60 buffer layers due to the small interaction of the molecules and C60 islands. This fact motivated us to deposit a multilayer of helicene molecules onto the C60 layers grown on the Au(111) surface, leading to the fact that the helicene/C60 multilayer showed strong luminescence with the molecules character. We consider that such strong light emission from the multilayer of helicene molecules has a plasmon origin strongly modulated by the molecular electronic states of (M)-[7]TH-diol molecules.
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Affiliation(s)
- Paweł Krukowski
- Department of Solid State Physics, Faculty of Physics and Applied Informatics, University of Lodz, 90–236 Łódź, Poland
- Correspondence:
| | - Takuma Hattori
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, Suita 565–0871, Japan
| | - Megumi Akai-Kasaya
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, Suita 565–0871, Japan
| | - Akira Saito
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, Suita 565–0871, Japan
| | - Hideji Osuga
- Department of Materials Science and Chemistry, Faculty of Systems Engineering, Wakayama University, Wakayama 640-8510, Japan
| | - Yuji Kuwahara
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, Suita 565–0871, Japan
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30
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Doležal J, Canola S, Hapala P, de Campos Ferreira RC, Merino P, Švec M. Evidence of exciton-libron coupling in chirally adsorbed single molecules. Nat Commun 2022; 13:6008. [PMID: 36224183 PMCID: PMC9556530 DOI: 10.1038/s41467-022-33653-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 09/28/2022] [Indexed: 11/18/2022] Open
Abstract
Interplay between motion of nuclei and excitations has an important role in molecular photophysics of natural and artificial structures. Here we provide a detailed analysis of coupling between quantized librational modes (librons) and charged excited states (trions) on single phthalocyanine dyes adsorbed on a surface. By means of tip-induced electroluminescence performed with a scanning probe microscope, we identify libronic signatures in spectra of chirally adsorbed phthalocyanines and find that these signatures are absent from spectra of symmetrically adsorbed species. We create a model of the libronic coupling based on the Franck-Condon principle to simulate the spectral features. Experimentally measured librational spectra match very well the theoretically calculated librational eigenenergies and peak intensities (Franck-Condon factors). Moreover, the comparison reveals an unexpected depopulation channel for the zero libron of the excited state that can be effectively controlled by tuning the size of the nanocavity. Our results showcase the possibility of characterizing the dynamics of molecules by their low-energy molecular modes using µeV-resolved tip-enhanced spectroscopy. Vibronic coupling in molecules plays an essential role in photophysics. Here, the authors observe optical fingerprints of the coupling between librational states and charged excited states in a single phthalocyanine molecule chirally absorbed on a surface.
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Affiliation(s)
- Jiří Doležal
- Institute of Physics, Czech Academy of Sciences, CZ16200, Praha 6, Czech Republic. .,Faculty of Mathematics and Physics, Charles University, CZ12116, Praha 2, Czech Republic.
| | - Sofia Canola
- Institute of Physics, Czech Academy of Sciences, CZ16200, Praha 6, Czech Republic
| | - Prokop Hapala
- Institute of Physics, Czech Academy of Sciences, CZ16200, Praha 6, Czech Republic
| | | | - Pablo Merino
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, E08193, Barcelona, Spain.,Instituto de Ciencia de Materiales de Madrid; CSIC, E28049, Madrid, Spain
| | - Martin Švec
- Institute of Physics, Czech Academy of Sciences, CZ16200, Praha 6, Czech Republic. .,Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, CZ16000, Praha 6, Czech Republic.
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31
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Homberg J, Weismann A, Markussen T, Berndt R. Resonance-Enhanced Vibrational Spectroscopy of Molecules on a Superconductor. PHYSICAL REVIEW LETTERS 2022; 129:116801. [PMID: 36154405 DOI: 10.1103/physrevlett.129.116801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/13/2022] [Accepted: 07/13/2022] [Indexed: 06/16/2023]
Abstract
Molecular vibrational spectroscopy with the scanning tunneling microscope is feasible but usually detects few vibrational modes. We harness sharp Yu-Shiba-Rusinov states observed from molecules on a superconductor to significantly enhance the vibrational signal. From a lead phthalocyanine molecule 46 vibrational peaks are resolved enabling a comparison with calculated modes. The energy resolution is improved beyond the thermal broadening limit and shifts induced by neighbor molecules or the position of the microscope tip are determined. Vice versa, spectra of vibrational modes are used to measure the effect of an electrical field on the energy of Yu-Shiba-Rusinov states. The method may help to further probe the interaction of molecules with their environment and to better understand selection rules for vibrational excitations.
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Affiliation(s)
- Jan Homberg
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Alexander Weismann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Troels Markussen
- Synopsys Denmark, Fruebjergvej 3, Postbox 4, DK-2100 Copenhagen, Denmark
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
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32
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First-principles study on the luminescence property of a single-molecule near metallic nanoclusters. COMPUT THEOR CHEM 2022. [DOI: 10.1016/j.comptc.2022.113813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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33
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Imada H, Imai-Imada M, Ouyang X, Muranaka A, Kim Y. Anti-Kasha emissions of single molecules in a plasmonic nanocavity. J Chem Phys 2022; 157:104302. [DOI: 10.1063/5.0102087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Kasha's rule generally holds true for solid-state molecular systems, where the rates of internal conversion and vibrational relaxation are sufficiently higher than the luminescence rate. In contrast, in systems where plasmons and matter interact strongly, the luminescence rate is significantly enhanced, leading to the emergence of luminescence that does not obey Kasha's rule. In this work, we investigate the anti-Kasha emissions of single molecules, free-base and magnesium naphthalocyanine (H2Nc and MgNc), in a plasmonic nanocavity formed between the tip of a scanning tunneling microscope (STM) and metal substrate. A narrow-line tunable laser was employed to precisely reveal the excited-state levels of a single molecule located under the tip and to selectively excite it into a specific excited state, followed by obtaining STM-photoluminescence (STM-PL) spectrum to reveal energy relaxation from the state. The excitation to higher-lying states of H2Nc caused various changes in the emission spectrum, such as broadening and the appearance of new peaks, implying the breakdown of Kasha's rule. These observations indicate emissions from the vibrationally excited states in the first singlet excited state ( S1) and second singlet excited state ( S2), as well as internal conversion from S2 to S1. Moreover, we obtained direct evidence of electronic and vibronic transitions from the vibrationally excited states, from the STM-PL measurements of MgNc. The results obtained herein shed light on the energy dynamics of molecular systems under a plasmonic field and highlight the possibility of obtaining various energy-converting functions using anti-Kasha processes.
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34
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Li P, Zhou L, Zhao C, Ju H, Gao Q, Si W, Cheng L, Hao J, Li M, Chen Y, Jia C, Guo X. Single-molecule nano-optoelectronics: insights from physics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:086401. [PMID: 35623319 DOI: 10.1088/1361-6633/ac7401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
Single-molecule optoelectronic devices promise a potential solution for miniaturization and functionalization of silicon-based microelectronic circuits in the future. For decades of its fast development, this field has made significant progress in the synthesis of optoelectronic materials, the fabrication of single-molecule devices and the realization of optoelectronic functions. On the other hand, single-molecule optoelectronic devices offer a reliable platform to investigate the intrinsic physical phenomena and regulation rules of matters at the single-molecule level. To further realize and regulate the optoelectronic functions toward practical applications, it is necessary to clarify the intrinsic physical mechanisms of single-molecule optoelectronic nanodevices. Here, we provide a timely review to survey the physical phenomena and laws involved in single-molecule optoelectronic materials and devices, including charge effects, spin effects, exciton effects, vibronic effects, structural and orbital effects. In particular, we will systematically summarize the basics of molecular optoelectronic materials, and the physical effects and manipulations of single-molecule optoelectronic nanodevices. In addition, fundamentals of single-molecule electronics, which are basic of single-molecule optoelectronics, can also be found in this review. At last, we tend to focus the discussion on the opportunities and challenges arising in the field of single-molecule optoelectronics, and propose further potential breakthroughs.
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Affiliation(s)
- Peihui Li
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Li Zhou
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Cong Zhao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Hongyu Ju
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, People's Republic of China
| | - Qinghua Gao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Wei Si
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Li Cheng
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Jie Hao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Mengmeng Li
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Yijian Chen
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Chuancheng Jia
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, People's Republic of China
| | - Xuefeng Guo
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, People's Republic of China
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35
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Kong FF, Tian XJ, Zhang Y, Zhang Y, Chen G, Yu YJ, Jing SH, Gao HY, Luo Y, Yang JL, Dong ZC, Hou JG. Wavelike electronic energy transfer in donor-acceptor molecular systems through quantum coherence. NATURE NANOTECHNOLOGY 2022; 17:729-736. [PMID: 35668169 DOI: 10.1038/s41565-022-01142-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 04/25/2022] [Indexed: 06/15/2023]
Abstract
Quantum-coherent intermolecular energy transfer is believed to play a key role in light harvesting in photosynthesis and photovoltaics. So far, a direct, real-space demonstration of quantum coherence in donor-acceptor systems has been lacking because of the fragile quantum coherence in lossy molecular systems. Here, we precisely control the separations in well-defined donor-acceptor model systems and unveil a transition from incoherent to coherent electronic energy transfer. We monitor the fluorescence from the heterodimers with subnanometre resolution through scanning tunnelling microscopy induced luminescence. With decreasing intermolecular distance, the dipole coupling strength increases and two new emission peaks emerge: a low-intensity peak blueshifted from the donor emission, and an intense peak redshifted from the acceptor emission. Spatially resolved spectroscopic images of the redshifted emission exhibit a σ antibonding-like pattern and thus indicate a delocalized nature of the excitonic state over the whole heterodimer due to the in-phase superposition of molecular excited states. These observations suggest that the exciton can travel coherently through the whole heterodimer as a quantum-mechanical wavepacket. In our model system, the wavelike quantum-coherent transfer channel is three times more efficient than the incoherent channel.
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Affiliation(s)
- Fan-Fang Kong
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
| | - Xiao-Jun Tian
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
| | - Yang Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China.
- School of Physics and Department of Chemical Physics, University of Science and Technology of China, Hefei, China.
- Hefei National Laboratory, Hefei, China.
| | - Yao Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- School of Physics and Department of Chemical Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, Hefei, China
| | - Gong Chen
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
| | - Yun-Jie Yu
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
| | - Shi-Hao Jing
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
| | - Hong-Ying Gao
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, China
| | - Yi Luo
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- School of Physics and Department of Chemical Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, Hefei, China
| | - Jin-Long Yang
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China
- School of Physics and Department of Chemical Physics, University of Science and Technology of China, Hefei, China
- Hefei National Laboratory, Hefei, China
| | - Zhen-Chao Dong
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China.
- School of Physics and Department of Chemical Physics, University of Science and Technology of China, Hefei, China.
- Hefei National Laboratory, Hefei, China.
| | - J G Hou
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, China.
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36
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Cheng B, Wu D, Bian K, Tian Y, Guo C, Liu K, Jiang Y. A qPlus-based scanning probe microscope compatible with optical measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:043701. [PMID: 35489886 DOI: 10.1063/5.0082369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
We design and develop a scanning probe microscope (SPM) system based on the qPlus sensor for atomic-scale optical experiments. The microscope operates under ultrahigh vacuum and low temperature (6.2 K). In order to obtain high efficiency of light excitation and collection, two front lenses with high numerical apertures (N.A. = 0.38) driven by compact nano-positioners are directly integrated on the scanner head without degrading its mechanical and thermal stability. The electric noise floor of the background current is 5 fA/Hz1/2, and the maximum vibrational noise of the tip height is below 200 fm/Hz1/2. The drift of the tip-sample spacing is smaller than 0.1 pm/min. Such a rigid scanner head yields small background noise (oscillation amplitude of ∼2 pm without excitation) and high quality factor (Q factor up to 140 000) for the qPlus sensor. Atomic-resolution imaging and inelastic electron tunneling spectroscopy are obtained under the scanning tunneling microscope mode on the Au(111) surface. The hydrogen-bonding structure of two-dimensional (2D) ice on the Au(111) surface is clearly resolved under the atomic force microscope (AFM) mode with a CO-terminated tip. Finally, the electroluminescence spectrum from a plasmonic AFM tip is demonstrated, which paves the way for future photon-assisted SPM experiments.
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Affiliation(s)
- Bowei Cheng
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Da Wu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Ke Bian
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Ye Tian
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Chaoyu Guo
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Kaihui Liu
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
| | - Ying Jiang
- International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China
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37
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Peña Román RJ, Auad Y, Grasso L, Padilha LA, Alvarez F, Barcelos ID, Kociak M, Zagonel LF. Design and implementation of a device based on an off-axis parabolic mirror to perform luminescence experiments in a scanning tunneling microscope. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:043704. [PMID: 35489916 DOI: 10.1063/5.0078423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/27/2022] [Indexed: 06/14/2023]
Abstract
We present the design, implementation, and illustrative results of a light collection/injection strategy based on an off-axis parabolic mirror collector for a low-temperature Scanning Tunneling Microscope (STM). This device allows us to perform STM induced Light Emission (STM-LE) and Cathodoluminescence (STM-CL) experiments and in situ Photoluminescence (PL) and Raman spectroscopy as complementary techniques. Considering the Étendue conservation and using an off-axis parabolic mirror, it is possible to design a light collection and injection system that displays 72% of collection efficiency (considering the hemisphere above the sample surface) while maintaining high spectral resolution and minimizing signal loss. The performance of the STM is tested by atomically resolved images and scanning tunneling spectroscopy results on standard sample surfaces. The capabilities of our system are demonstrated by performing STM-LE on metallic surfaces and two-dimensional semiconducting samples, observing both plasmonic and excitonic emissions. In addition, we carried out in situ PL measurements on semiconducting monolayers and quantum dots and in situ Raman on graphite and hexagonal boron nitride (h-BN) samples. Additionally, STM-CL and PL were obtained on monolayer h-BN gathering luminescence spectra that are typically associated with intragap states related to carbon defects. The results show that the flexible and efficient light injection and collection device based on an off-axis parabolic mirror is a powerful tool to study several types of nanostructures with multiple spectroscopic techniques in correlation with their morphology at the atomic scale and electronic structure.
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Affiliation(s)
- Ricardo Javier Peña Román
- "Gleb Wataghin" Institute of Physics, University of Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil
| | - Yves Auad
- "Gleb Wataghin" Institute of Physics, University of Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil
| | - Lucas Grasso
- "Gleb Wataghin" Institute of Physics, University of Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil
| | - Lazaro A Padilha
- "Gleb Wataghin" Institute of Physics, University of Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil
| | - Fernando Alvarez
- "Gleb Wataghin" Institute of Physics, University of Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil
| | - Ingrid David Barcelos
- Brazilian Synchrotron Light Laboratory (LNLS), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-970 Campinas, SP, Brazil
| | - Mathieu Kociak
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - Luiz Fernando Zagonel
- "Gleb Wataghin" Institute of Physics, University of Campinas-UNICAMP, 13083-859 Campinas, SP, Brazil
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38
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Vauthey E. Watching Excited-State Symmetry Breaking in Multibranched Push-Pull Molecules. J Phys Chem Lett 2022; 13:2064-2071. [PMID: 35212550 DOI: 10.1021/acs.jpclett.2c00259] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The emissive properties of symmetric molecules containing several donor-acceptor branches are often similar to those of the single-branched analogues. This is due to the at least partial localization of the excitation on one branch. Detailed understanding of this excited-state symmetry breaking (ES-SB) requires the ability to monitor this process in real time. Over the past few years, several spectroscopic approaches were shown to enable visualization of ES-SB and of its dynamics. They include the detection of new vibrational or electronic absorption bands associated with transitions that are forbidden in the symmetric excited state. Alternatively, ES-SB can be detected by observing transitions that become weaker or vanish upon localization of the excitation. Herein, we discuss these different approaches as well as their merits and weaknesses.
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Affiliation(s)
- Eric Vauthey
- Department of Physical Chemistry, University of Geneva, 30 Quai Ernest-Ansermet, CH-1211 Geneva, Switzerland
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39
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Orbital-resolved visualization of single-molecule photocurrent channels. Nature 2022; 603:829-834. [PMID: 35354999 DOI: 10.1038/s41586-022-04401-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 01/03/2022] [Indexed: 11/08/2022]
Abstract
Given its central role in utilizing light energy, photoinduced electron transfer (PET) from an excited molecule has been widely studied1-6. However, even though microscopic photocurrent measurement methods7-11 have made it possible to correlate the efficiency of the process with local features, spatial resolution has been insufficient to resolve it at the molecular level. Recent work has, however, shown that single molecules can be efficiently excited and probed when combining a scanning tunnelling microscope (STM) with localized plasmon fields driven by a tunable laser12,13. Here we use that approach to directly visualize with atomic-scale resolution the photocurrent channels through the molecular orbitals of a single free-base phthalocyanine (FBPc) molecule, by detecting electrons from its first excited state tunnelling through the STM tip. We find that the direction and the spatial distribution of the photocurrent depend sensitively on the bias voltage, and detect counter-flowing photocurrent channels even at a voltage where the averaged photocurrent is near zero. Moreover, we see evidence of competition between PET and photoluminescence12, and find that we can control whether the excited molecule primarily relaxes through PET or photoluminescence by positioning the STM tip with three-dimensional, atomic precision. These observations suggest that specific photocurrent channels can be promoted or suppressed by tuning the coupling to excited-state molecular orbitals, and thus provide new perspectives for improving energy-conversion efficiencies by atomic-scale electronic and geometric engineering of molecular interfaces.
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40
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Haupa KA, Krappel NP, Strelnikov D, Kappes MM. Vibrationally Resolved Absorption and Luminescence Spectra of Mass-Selected Free-Base and Zinc Phthalocyanine Radical Cations Isolated in Solid Ne. J Phys Chem A 2022; 126:593-599. [PMID: 35044185 DOI: 10.1021/acs.jpca.1c09916] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We report the first vibrationally well-resolved absorption and laser-induced fluorescence spectra of the radical cations of free-base phthalocyanine (H2Pc+) and zinc phthalocyanine (ZnPc+) isolated in 5 K neon matrices and compare them to the spectral properties of the corresponding neutrals. The samples were generated by low-energy deposition of the mass-selected ions. The spectra are also discussed in terms of time-dependent density functional theory calculations and compared with recently reported scanning tunneling microscopy-induced single-molecule luminescence of the same species adsorbed on NaCl-covered Au(111) or Ag(111) single crystal supports.
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Affiliation(s)
- Karolina A Haupa
- Institute of Physical Chemistry II, KIT, Fritz-Haber-Weg 2, Karlsruhe 76131, Germany
| | - Niklas P Krappel
- Institute of Physical Chemistry II, KIT, Fritz-Haber-Weg 2, Karlsruhe 76131, Germany
| | - Dmitry Strelnikov
- Institute of Physical Chemistry II, KIT, Fritz-Haber-Weg 2, Karlsruhe 76131, Germany
| | - Manfred M Kappes
- Institute of Physical Chemistry II, KIT, Fritz-Haber-Weg 2, Karlsruhe 76131, Germany.,Institute of Nanotechnology, KIT, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
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41
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Qiu F, Gong ZY, Cao D, Song C, Tian G, Duan S, Luo Y. Optical Images of Molecular Vibronic Couplings from Tip-Enhanced Fluorescence Excitation Spectroscopy. JACS AU 2022; 2:150-158. [PMID: 35098231 PMCID: PMC8790811 DOI: 10.1021/jacsau.1c00442] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Indexed: 06/14/2023]
Abstract
Tip-based photoemission spectroscopic techniques have now achieved subnanometer resolution that allows visualization of the chemical structure and even the ground-state vibrational modes of a single molecule. However, the ability to visualize the interplay between electronic and nuclear motions of excited states, i.e., vibronic couplings, is yet to be explored. Herein, we theoretically propose a new technique, namely, tip-enhanced fluorescence excitation (TEFE). TEFE takes advantage of the highly confined plasmonic field and thus can offer a possibility to directly visualize the vibronic effect of a single molecule in real space for arbitrary excited states in a given energy window. Numerical simulations for a single porphine molecule confirm that vibronic couplings originating from Herzberg-Teller (HT) active modes can be visually identified. TEFE further enables high-order vibrational transitions that are normally suppressed in the other plasmon-based processes. Images of the combination vibrational transitions have the same pattern as that of their parental HT active mode's fundamental transition, providing a direct protocol for measurements of the activity of Franck-Condon modes of selected excited states. These findings strongly suggest that TEFE is a powerful strategy to identify the involvement of molecular moieties in the complicated electron-nuclear interactions of the excited states at the single-molecule level.
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Affiliation(s)
- Feifei Qiu
- State
Key Laboratory of Metastable Materials Science & Technology and
Key Laboratory for Microstructural Material Physics of Hebei Province,
School of Science, Yanshan University, Qinhuangdao 066004, P.R. China
| | - Zu-Yong Gong
- Collaborative
Innovation Center of Chemistry for Energy Materials, Shanghai Key
Laboratory of Molecular Catalysis and Innovative Materials, MOE Key
Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai 200433, P.R. China
| | - Dongwei Cao
- State
Key Laboratory of Metastable Materials Science & Technology and
Key Laboratory for Microstructural Material Physics of Hebei Province,
School of Science, Yanshan University, Qinhuangdao 066004, P.R. China
| | - Ce Song
- Hefei
National Laboratory for Physical Sciences at the Microscale and Synergetic
Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei 230026 Anhui, P.R. China
- Department
of Theoretical Chemistry and Biology, School of Engineering Sciences
in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, S-106 91 Stockholm, Sweden
| | - Guangjun Tian
- State
Key Laboratory of Metastable Materials Science & Technology and
Key Laboratory for Microstructural Material Physics of Hebei Province,
School of Science, Yanshan University, Qinhuangdao 066004, P.R. China
| | - Sai Duan
- Collaborative
Innovation Center of Chemistry for Energy Materials, Shanghai Key
Laboratory of Molecular Catalysis and Innovative Materials, MOE Key
Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai 200433, P.R. China
| | - Yi Luo
- Hefei
National Laboratory for Physical Sciences at the Microscale and Synergetic
Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei 230026 Anhui, P.R. China
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42
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Ma Y, Kalt RA, Stemmer A. Local strain and tunneling current modulate excitonic luminescence in MoS 2 monolayers. RSC Adv 2022; 12:24922-24929. [PMID: 36199876 PMCID: PMC9434384 DOI: 10.1039/d2ra05123k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 08/26/2022] [Indexed: 11/21/2022] Open
Abstract
Local strain in monolayer molybdenum disulfide (MoS2) on an evaporated Au surface is studied by scanning tunneling microscopy (STM) induced excitonic luminescence on a length scale of 10 nm.
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Affiliation(s)
- Yalan Ma
- Nanotechnology Group, ETH Zürich, Säumerstrasse 4, Rüschlikon, 8803, Switzerland
| | - Romana Alice Kalt
- Nanotechnology Group, ETH Zürich, Säumerstrasse 4, Rüschlikon, 8803, Switzerland
| | - Andreas Stemmer
- Nanotechnology Group, ETH Zürich, Säumerstrasse 4, Rüschlikon, 8803, Switzerland
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43
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Tian G, Qiu F, Song C, Duan S, Luo Y. Electric Field Controlled Single-Molecule Optical Switch by Through-Space Charge Transfer State. J Phys Chem Lett 2021; 12:9094-9099. [PMID: 34520213 DOI: 10.1021/acs.jpclett.1c02578] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Controlling the photon emission property of a single molecule is an important goal for nano-optics. We propose here a new mechanism for a single-molecule optical switch that utilizes the in situ electric field (EF) in biased metallic nanojunctions to control photon emission of molecules with through-space charge transfer (TSCT) excited states. The EF-induced Stark effect is capable of flipping the order of the bright noncharge transfer state and dark TSCT state, resulting in the anticipated switching behavior. The proposed mechanism was theoretically verified by scanning tunneling microscope-induced electroluminescence from a naphtalenediimide cyclophane molecule under experimentally accessible conditions. Simulations show that the proposed switching effect can be obtained by changing either bias polarity, which alters the polarization of the field, or tip-height, which affects the magnitude of the field. Our finding indicates that the in situ EF could play an important role in the design of optoelectronic molecular devices.
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Affiliation(s)
- Guangjun Tian
- State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, P. R. China
| | - Feifei Qiu
- State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, P. R. China
| | - Ce Song
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, 230026 Anhui, P. R. China
- Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, S-106 91 Stockholm, Sweden
| | - Sai Duan
- Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, MOE Key Laboratory of Computational Physical Sciences, Department of Chemistry, Fudan University, Shanghai 200433, P. R. China
| | - Yi Luo
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, 230026 Anhui, P. R. China
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44
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Yokota Y, Wong RA, Hong M, Hayazawa N, Kim Y. Monatomic Iodine Dielectric Layer for Multimodal Optical Spectroscopy of Dye Molecules on Metal Surfaces. J Am Chem Soc 2021; 143:15205-15214. [PMID: 34496210 DOI: 10.1021/jacs.1c06303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fluorescence and Raman scattering spectroscopies have been used in various research fields such as chemistry, electrochemistry, and biochemistry because they can easily obtain detailed information about molecules at interfaces with visible light. In particular, multimodal fluorescence and Raman scattering spectroscopy have recently attracted significant attention, which enables us to distinguish chemical species and their electronic states that are important for expressing various functions. However, a special strategy is required to perform simultaneous measurements because the cross sections of fluorescence and Raman scattering differ by as much as ∼1014. In this study, we propose a method for the simultaneous measurement of dye molecules on a metal surface using a monatomic layer of iodine as the dielectric layer. The method is based on adequately quenching the photoexcited state of the molecules near the metal surface to weaken the fluorescence intensity and using the resonance effect to increase the Raman signal. We have validated this concept by experiments with insulating layers of different thicknesses and dye molecules of different chemical structures. The proposed multimodal strategy paves the way for various applications such as catalytic chemistry and electrochemistry, where the adsorption structure and electronic states of molecular species near the metal surface determine functionalities.
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Affiliation(s)
- Yasuyuki Yokota
- Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.,JST PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Raymond A Wong
- Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Misun Hong
- Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Norihiko Hayazawa
- Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yousoo Kim
- Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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45
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Rosławska A, Merino P, Grewal A, Leon CC, Kuhnke K, Kern K. Atomic-Scale Structural Fluctuations of a Plasmonic Cavity. NANO LETTERS 2021; 21:7221-7227. [PMID: 34428071 PMCID: PMC8887667 DOI: 10.1021/acs.nanolett.1c02207] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Optical spectromicroscopies, which can reach atomic resolution due to plasmonic enhancement, are perturbed by spontaneous intensity modifications. Here, we study such fluctuations in plasmonic electroluminescence at the single-atom limit profiting from the precision of a low-temperature scanning tunneling microscope. First, we investigate the influence of a controlled single-atom transfer from the tip to the sample on the plasmonic properties of the junction. Next, we form a well-defined atomic contact of several quanta of conductance. In contact, we observe changes of the electroluminescence intensity that can be assigned to spontaneous modifications of electronic conductance, plasmonic excitation, and optical antenna properties all originating from minute atomic rearrangements at or near the contact. Our observations are relevant for the understanding of processes leading to spontaneous intensity variations in plasmon-enhanced atomic-scale spectroscopies such as intensity blinking in picocavities.
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Affiliation(s)
- Anna Rosławska
- Max-Planck-Institut
für Festkörperforschung, D-70569 Stuttgart, Germany
- Université
de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Pablo Merino
- Max-Planck-Institut
für Festkörperforschung, D-70569 Stuttgart, Germany
- Instituto
de Ciencia de Materiales de Madrid, CSIC, E-28049 Madrid, Spain
- Instituto
de Física Fundamental, CSIC, E-28006 Madrid, Spain
| | - Abhishek Grewal
- Max-Planck-Institut
für Festkörperforschung, D-70569 Stuttgart, Germany
| | | | - Klaus Kuhnke
- Max-Planck-Institut
für Festkörperforschung, D-70569 Stuttgart, Germany
| | - Klaus Kern
- Max-Planck-Institut
für Festkörperforschung, D-70569 Stuttgart, Germany
- Institut
de Physique, École Polytechnique
Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
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46
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Maier S, Stöhr M. Molecular assemblies on surfaces: towards physical and electronic decoupling of organic molecules. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2021; 12:950-956. [PMID: 34540518 PMCID: PMC8404214 DOI: 10.3762/bjnano.12.71] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Affiliation(s)
- Sabine Maier
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany
| | - Meike Stöhr
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
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47
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Balzer N, Lukášek J, Valášek M, Rai V, Sun Q, Gerhard L, Wulfhekel W, Mayor M. Synthesis and Surface Behaviour of NDI Chromophores Mounted on a Tripodal Scaffold: Towards Self-Decoupled Chromophores for Single-Molecule Electroluminescence. Chemistry 2021; 27:12144-12155. [PMID: 34152041 PMCID: PMC8457086 DOI: 10.1002/chem.202101264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Indexed: 12/01/2022]
Abstract
This paper reports the efficient synthesis, absorption and emission spectra, and the electrochemical properties of a series of 2,6-disubstituted naphthalene-1,4,5,8-tetracarboxdiimide (NDI) tripodal molecules with thioacetate anchors for their surface investigations. Our studies showed that, in particular, the pyrrolidinyl group with its strong electron-donating properties enhanced the fluorescence of such core-substituted NDI chromophores and caused a significant bathochromic shift in the absorption spectrum with a correspondingly narrowed bandgap of 1.94 eV. Cyclic voltammetry showed the redox properties of NDIs to be influenced by core substituents. The strong electron-donating character of pyrrolidine substituents results in rather high HOMO and LUMO levels of -5.31 and -3.37 eV when compared with the parental unsubstituted NDI. UHV-STM measurements of a sub-monolayer of the rigid tripodal NDI chromophores spray deposited on Au(111) show that these molecules mainly tend to adsorb flat in a pairwise fashion on the surface and form unordered films. However, the STML experiments also revealed a few molecular clusters, which might consist of upright oriented molecules protruding from the molecular island and show electroluminescence photon spectra with high electroluminescence yields of up to 6×10-3 . These results demonstrate the promising potential of the NDI tripodal chromophores for the fabrication of molecular devices profiting from optical features of the molecular layer.
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Affiliation(s)
- Nico Balzer
- Institute of NanotechnologyKarlsruhe Institute of TechnologyP.O. Box 364076021KarlsruheGermany
| | - Jan Lukášek
- Institute of NanotechnologyKarlsruhe Institute of TechnologyP.O. Box 364076021KarlsruheGermany
| | - Michal Valášek
- Institute of NanotechnologyKarlsruhe Institute of TechnologyP.O. Box 364076021KarlsruheGermany
| | - Vibhuti Rai
- Institute of Quantum Materials and TechnologiesKarlsruhe Institute of Technology76021KarlsruheGermany
| | - Qing Sun
- Institute of Quantum Materials and TechnologiesKarlsruhe Institute of Technology76021KarlsruheGermany
| | - Lukas Gerhard
- Institute of Quantum Materials and TechnologiesKarlsruhe Institute of Technology76021KarlsruheGermany
| | - Wulf Wulfhekel
- Institute of Quantum Materials and TechnologiesKarlsruhe Institute of Technology76021KarlsruheGermany
- Physikalisches InstitutKarlsruhe Institute of TechnologyWolfgang-Gaede-Straße 176131KarlsruheGermany
| | - Marcel Mayor
- Institute of NanotechnologyKarlsruhe Institute of TechnologyP.O. Box 364076021KarlsruheGermany
- Department of ChemistryUniversity of BaselSt. Johanns-Ring 194056BaselSwitzerland
- Lehn Institute of Functional MaterialsSchool of ChemistrySun Yat-Sen UniversityGuangzhou, Guangdong510275P. R. China
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48
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Cao S, Rosławska A, Doppagne B, Romeo M, Féron M, Chérioux F, Bulou H, Scheurer F, Schull G. Energy funnelling within multichromophore architectures monitored with subnanometre resolution. Nat Chem 2021; 13:766-770. [PMID: 34031563 DOI: 10.1038/s41557-021-00697-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/08/2021] [Indexed: 02/04/2023]
Abstract
The funnelling of energy within multichromophoric assemblies is at the heart of the efficient conversion of solar energy by plants. The detailed mechanisms of this process are still actively debated as they rely on complex interactions between a large number of chromophores and their environment. Here we used luminescence induced by scanning tunnelling microscopy to probe model multichromophoric structures assembled on a surface. Mimicking strategies developed by photosynthetic systems, individual molecules were used as ancillary, passive or blocking elements to promote and direct resonant energy transfer between distant donor and acceptor units. As it relies on organic chromophores as the elementary components, this approach constitutes a powerful model to address fundamental physical processes at play in natural light-harvesting complexes.
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Affiliation(s)
- Shuiyan Cao
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, Strasbourg, France.,Department of Applied Physics, Nanjing University of Aeronautics and Astronautics, Nanjing, China
| | - Anna Rosławska
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, Strasbourg, France.
| | | | | | - Michel Féron
- Université Bourgogne Franche-Comté, FEMTO-ST, UFC, CNRS, Besançon, France
| | - Frédéric Chérioux
- Université Bourgogne Franche-Comté, FEMTO-ST, UFC, CNRS, Besançon, France
| | - Hervé Bulou
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, Strasbourg, France
| | - Fabrice Scheurer
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, Strasbourg, France
| | - Guillaume Schull
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, Strasbourg, France.
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49
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Imada H, Imai-Imada M, Miwa K, Yamane H, Iwasa T, Tanaka Y, Toriumi N, Kimura K, Yokoshi N, Muranaka A, Uchiyama M, Taketsugu T, Kato YK, Ishihara H, Kim Y. Single-molecule laser nanospectroscopy with micro-electron volt energy resolution. Science 2021; 373:95-98. [PMID: 34210883 DOI: 10.1126/science.abg8790] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 05/22/2021] [Indexed: 12/16/2022]
Abstract
Ways to characterize and control excited states at the single-molecule and atomic levels are needed to exploit excitation-triggered energy-conversion processes. Here, we present a single-molecule spectroscopic method with micro-electron volt energy and submolecular-spatial resolution using laser driving of nanocavity plasmons to induce molecular luminescence in scanning tunneling microscopy. This tunable and monochromatic nanoprobe allows state-selective characterization of the energy levels and linewidths of individual electronic and vibrational quantum states of a single molecule. Moreover, we demonstrate that the energy levels of the states can be finely tuned by using the Stark effect and plasmon-exciton coupling in the tunneling junction. Our technique and findings open a route to the creation of designed energy-converting functions by using tuned energy levels of molecular systems.
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Affiliation(s)
- Hiroshi Imada
- Surface and Interface Science Laboratory, RIKEN, Wako, Saitama 351-0198, Japan. .,PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Miyabi Imai-Imada
- Surface and Interface Science Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Kuniyuki Miwa
- Surface and Interface Science Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.,Institute for Molecular Science, Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Hidemasa Yamane
- Department of Physics and Electronics, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Takeshi Iwasa
- PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan.,Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.,Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 060-0810, Japan
| | - Yusuke Tanaka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.,Advanced Elements Chemistry Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Naoyuki Toriumi
- Advanced Elements Chemistry Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Kensuke Kimura
- Surface and Interface Science Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Nobuhiko Yokoshi
- Department of Physics and Electronics, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan
| | - Atsuya Muranaka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.,Advanced Elements Chemistry Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Masanobu Uchiyama
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.,Advanced Elements Chemistry Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Tetsuya Taketsugu
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan.,Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 060-0810, Japan
| | - Yuichiro K Kato
- Nanoscale Quantum Photonics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.,Quantum Optoelectronics Research Team, RIKEN Center for Advanced Photonics, Wako, Saitama 351-0198, Japan
| | - Hajime Ishihara
- Department of Physics and Electronics, Osaka Prefecture University, Sakai, Osaka 599-8531, Japan.,Department of Materials Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan.,Center for Quantum Information and Quantum Biology, Osaka University 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Yousoo Kim
- Surface and Interface Science Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
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50
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Liu Y, Bian Y, Zhang Y, Hang C, Zhang X, Lou S, Jin Q. Fluorescence of CoTPP Mediated by the Plasmon-Exciton Coupling Effect in the Tunneling Junction. J Phys Chem Lett 2021; 12:5349-5356. [PMID: 34076440 DOI: 10.1021/acs.jpclett.1c01123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
CoTPP, as a common hypsoporphyrin, is usually not a luminescent molecule because of the open-shell Co ion. In this paper, well-defined multilayer CoTPP molecules self-assembled on Au(111) surface are characterized layer by layer with scanning tunneling microscope (STM) induced luminescence. By using the highly localized STM tunneling current, we not only investigate the influence of bias polarity on the amplitude of distinct plasmonic emission resulted from the interaction between the metal substrate and the metal ions but also first obtain the light emission from the hypsoporphyrins in the tunneling junction. The density-matrix method and the combined approach of classical electrodynamics and first-principles calculation are used to explain the mechanism of the light emission. These findings may expand the underlying physics of plasmon-exciton coupling in STM nanocavity and reveal a new possible path to overcome the fluorescent potential of hypsoporphyrins by the intense localized electric fields.
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Affiliation(s)
- Yiting Liu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Yajie Bian
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Yuyi Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Chao Hang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Xiaolei Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, P. R. China
| | - Shitao Lou
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Qingyuan Jin
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
- Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China
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