1
|
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.
Collapse
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
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
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]
|
8
|
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: 6] [Impact Index Per Article: 3.0] [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.
Collapse
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.
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
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: 2] [Impact Index Per Article: 0.7] [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.
Collapse
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
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Zhu JZ, Chen G, Ijaz T, Li XG, Dong ZC. Influence of an atomistic protrusion at the tip apex on enhancing molecular emission in tunnel junctions: A theoretical study. J Chem Phys 2021; 154:214706. [PMID: 34240995 DOI: 10.1063/5.0048440] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Light emission from the gap of a scanning tunneling microscope can be used to investigate many optoelectronic processes at the single-molecule level and to gain insight into the fundamental photophysical mechanisms involved. One important issue is how to improve the quantum efficiency of quantum emitters in the nanometer-sized metallic gap so that molecule-specific emission can be clearly observed. Here, using electromagnetic simulations, we systematically investigate the influence of an atomic-scale protrusion at the tip apex on the emission properties of a point dipole in the plasmonic nanocavity. We found that such an atomistic protrusion can induce strong and spatially highly confined electric fields, thus increasing the quantum efficiency of molecular fluorescence over two orders of magnitude even when its dipole is oriented parallel to the metal surface, a situation occurring in most realistic single-molecule electroluminescence experiments. In addition, our theoretical simulations indicate that due to the lightning rod effect induced by the protrusion in a plasmonic nanocavity, the quantum efficiency increases monotonically as the tip approaches the dipole to the point of contact, instead of being quenched, thus explaining previous experimental observations with ever-enhancing fluorescence. Furthermore, we also examine in detail how the protrusion radius, height, and material affect the protrusion-induced emission enhancement. These results are believed to be instructive for further studies on the optoelectronic properties of single molecules in tip-based plasmonic nanocavities.
Collapse
Affiliation(s)
- Jia-Zhe Zhu
- Hefei National Laboratory 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
| | - Gong Chen
- Hefei National Laboratory 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
| | - Talha Ijaz
- Hefei National Laboratory 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-Guang Li
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Zhen-Chao Dong
- Hefei National Laboratory 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
| |
Collapse
|
14
|
Probing intramolecular vibronic coupling through vibronic-state imaging. Nat Commun 2021; 12:1280. [PMID: 33627671 PMCID: PMC7904785 DOI: 10.1038/s41467-021-21571-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 02/03/2021] [Indexed: 12/04/2022] Open
Abstract
Vibronic coupling is a central issue in molecular spectroscopy. Here we investigate vibronic coupling within a single pentacene molecule in real space by imaging the spatial distribution of single-molecule electroluminescence via highly localized excitation of tunneling electrons in a controlled plasmonic junction. The observed two-spot orientation for certain vibronic-state imaging is found to be evidently different from the purely electronic 0–0 transition, rotated by 90°, which reflects the change in the transition dipole orientation from along the molecular short axis to the long axis. Such a change reveals the occurrence of strong vibronic coupling associated with a large Herzberg–Teller contribution, going beyond the conventional Franck–Condon picture. The emergence of large vibration-induced transition charges oscillating along the long axis is found to originate from the strong dynamic perturbation of the anti-symmetric vibration on those carbon atoms with large transition density populations during electronic transitions. Vibronic coupling is a key feature of molecular electronic transitions, but its visualization in real space is an experimental challenge. Here the authors, using scanning tunneling microscopy induced luminescence, resolve the effect of vibronic coupling with different modes on the electron distributions in real space in a single pentacene molecule.
Collapse
|
15
|
Farrukh A, Tian XJ, Kong FF, Yu YJ, Jing SH, Chen G, Zhang Y, Liao Y, Zhang Y, Dong ZC. Bias-polarity dependent electroluminescence from a single platinum phthalocyanine molecule. CHINESE J CHEM PHYS 2021. [DOI: 10.1063/1674-0068/cjcp2007114] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Aftab Farrukh
- 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, China
| | - Xiao-jun Tian
- 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, China
| | - Fan-fang Kong
- 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, China
| | - Yun-jie Yu
- 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, China
| | - Shi-hao Jing
- 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, China
| | - Gong Chen
- 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, China
| | - Yao Zhang
- 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, China
| | - Yuan Liao
- 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, China
| | - Yang Zhang
- 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, China
| | - Zhen-chao Dong
- 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, China
| |
Collapse
|
16
|
Luo Y, Kong FF, Tian XJ, Yu YJ, Zhang L, Chen G, Zhang Y, Zhang Y, Dong ZC. What can single-molecule Fano resonance tell? J Chem Phys 2021; 154:044309. [PMID: 33514086 DOI: 10.1063/5.0033200] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
In this work, we showcase applications of single-molecule Fano resonance (SMFR) measurements beyond the determination of molecular excitonic energy and associated dipole orientation. We use the SMFR measurement to probe the local influence of a man-made single chlorine vacancy on the molecular transition of a single zinc phthalocyanine, which clearly reveals the lifting-up of the double degeneracy of the excited states due to defect-induced configurational changes. Furthermore, time-trace SMFR measurements at different excitation voltages are used to track the tautomerization process in a free-base phthalocyanine. Different behaviors in switching between two inner-hydrogen configurations are observed with decreasing voltages, which helps to reveal the underlying tautomerization mechanism involving both the molecular electronic excited states and vibrational excited states in the ground state.
Collapse
Affiliation(s)
- Yang Luo
- Hefei National Laboratory 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
| | - Fan-Fang Kong
- Hefei National Laboratory 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 Laboratory 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
| | - Yun-Jie Yu
- Hefei National Laboratory 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 Laboratory 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
| | - Gong Chen
- Hefei National Laboratory 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
| | - Yao Zhang
- Hefei National Laboratory 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
| | - Yang Zhang
- Hefei National Laboratory 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
| | - Zhen-Chao Dong
- Hefei National Laboratory 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
| |
Collapse
|
17
|
Schultz JF, Li S, Jiang S, Jiang N. Optical scanning tunneling microscopy based chemical imaging and spectroscopy. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:463001. [PMID: 32702674 DOI: 10.1088/1361-648x/aba8c7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
Through coupling optical processes with the scanning tunneling microscope (STM), single-molecule chemistry and physics have been investigated at the ultimate spatial and temporal limit. Electrons and photons can be used to drive interactions and reactions in chemical systems and simultaneously probe their characteristics and consequences. In this review we introduce and review methods to couple optical imaging and spectroscopy with scanning tunneling microscopy. The integration of the STM and optical spectroscopy provides new insights into individual molecular adsorbates, surface-supported molecular assemblies, and two-dimensional materials with subnanoscale resolution, enabling the fundamental study of chemistry at the spatial and temporal limit. The inelastic scattering of photons by molecules and materials, that results in unique and sensitive vibrational fingerprints, will be considered with tip-enhanced Raman spectroscopy. STM-induced luminescence examines the intrinsic luminescence of organic adsorbates and their energy transfer and charge transfer processes with their surroundings. We also provide a survey of recent efforts to probe the dynamics of optical excitation at the molecular level with scanning tunneling microscopy in the context of light-induced photophysical and photochemical transformations.
Collapse
Affiliation(s)
- Jeremy F Schultz
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, United States of America
| | - Shaowei Li
- Department of Chemistry and Biochemistry, University of California, San Diego, CA 92093, United States of America
- Kavli Energy NanoScience Institute, University of California, Berkeley, CA 94720, United States of America
| | - Song Jiang
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Nan Jiang
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, United States of America
| |
Collapse
|
18
|
Rosławska A, Leon CC, Grewal A, Merino P, Kuhnke K, Kern K. Atomic-Scale Dynamics Probed by Photon Correlations. ACS NANO 2020; 14:6366-6375. [PMID: 32479059 PMCID: PMC7315641 DOI: 10.1021/acsnano.0c03704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Light absorption and emission have their origins in fast atomic-scale phenomena. To characterize these basic steps (e.g., in photosynthesis, luminescence, and quantum optics), it is necessary to access picosecond temporal and picometer spatial scales simultaneously. In this Perspective, we describe how state-of-the-art picosecond photon correlation spectroscopy combined with luminescence induced at the atomic scale with a scanning tunneling microscope (STM) enables such studies. We outline recent STM-induced luminescence work on single-photon emitters and the dynamics of excitons, charges, molecules, and atoms as well as several prospective experiments concerning light-matter interactions at the nanoscale. We also describe future strategies for measuring and rationalizing ultrafast phenomena at the nanoscale.
Collapse
Affiliation(s)
- Anna Rosławska
- Max-Planck-Institut
für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Christopher C. Leon
- Max-Planck-Institut
für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Abhishek Grewal
- Max-Planck-Institut
für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Pablo Merino
- Max-Planck-Institut
für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
- Instituto
de Ciencia de Materiales de Madrid, CSIC, c/Sor Juana Inés de la Cruz 3, E28049 Madrid, Spain
- Instituto
de Física Fundamental, CSIC, Serrano 121, E28006 Madrid, Spain
| | - 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, 1015 Lausanne, Switzerland
| |
Collapse
|
19
|
Wu X, Wang R, Liu N, Zou H, Shao B, Shao L, Yam C. Controlling the emission frequency of graphene nanoribbon emitters based on spatially excited topological boundary states. Phys Chem Chem Phys 2020; 22:8277-8283. [PMID: 32182306 DOI: 10.1039/c9cp06732a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Graphene nanoribbons (GNRs) with atomically precise heterojunction interfaces are exploited as nanoscale light emitting devices with modulable emission frequencies. By connecting GNRs with different widths and lengths, topological boundary states can be formed and manipulated. Using first-principles-based atomistic simulations, we studied the luminescence properties of a STM GNR junction and explored the applications of these topological states as nanoscale light sources. Taking advantage of the ultrahigh resolution of the STM tip, direct injection of high energy carriers at selected boundary states can be achieved. In this way, the emission color can be controlled by precisely changing the tip position. The GNR heterojunction can therefore represent a robust and controllable light-emitting device that takes a step forward towards the fabrication of nanoscale graphene-based optoelectronic devices.
Collapse
Affiliation(s)
- Xiaoyan Wu
- Beijing Computational Science Research Center, ZPark II, Beijing 100193, China.
| | | | | | | | | | | | | |
Collapse
|
20
|
Cabra G, Franco I, Galperin M. Optical properties of periodically driven open nonequilibrium quantum systems. J Chem Phys 2020; 152:094101. [DOI: 10.1063/1.5144779] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Gabriel Cabra
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, USA
| | - Ignacio Franco
- Department of Chemistry, University of Rochester, Rochester, New York 14627, USA
- Department of Physics, University of Rochester, Rochester, New York 14627, USA
| | - Michael Galperin
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, USA
| |
Collapse
|
21
|
Cohen G, Galperin M. Green’s function methods for single molecule junctions. J Chem Phys 2020; 152:090901. [DOI: 10.1063/1.5145210] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Guy Cohen
- The Raymond and Beverley Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 69978, Israel
- School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel
| | - Michael Galperin
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, USA
| |
Collapse
|
22
|
Yadalam HK, Mukamel S, Harbola U. Energy, Particle, and Photon Fluxes in Molecular Junctions. J Phys Chem Lett 2020; 11:1762-1766. [PMID: 32046490 DOI: 10.1021/acs.jpclett.0c00044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Electroluminescence from a current-carrying molecular junction at steady state is simulated. (Charge) particle conservation and energy conservation are satisfied by a perturbative expansion in the radiation/matter coupling. Our approach makes it possible to adopt standard tools of traditional (equilibrium) spectroscopy to study signals from open systems such as molecular junctions. The nonperturbative analysis of spontaneous light emission signals coincides with the perturbative approach for weak molecule-field coupling.
Collapse
Affiliation(s)
- Hari Kumar Yadalam
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Shaul Mukamel
- Department of Chemistry, University of California, Irvine, California 92614, United States
| | - Upendra Harbola
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| |
Collapse
|
23
|
Moorsom T, Rogers M, Scivetti I, Bandaru S, Teobaldi G, Valvidares M, Flokstra M, Lee S, Stewart R, Prokscha T, Gargiani P, Alosaimi N, Stefanou G, Ali M, Al Ma’Mari F, Burnell G, Hickey BJ, Cespedes O. Reversible spin storage in metal oxide-fullerene heterojunctions. SCIENCE ADVANCES 2020; 6:eaax1085. [PMID: 32219155 PMCID: PMC7083605 DOI: 10.1126/sciadv.aax1085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 12/12/2019] [Indexed: 06/10/2023]
Abstract
We show that hybrid MnOx/C60 heterojunctions can be used to design a storage device for spin-polarized charge: a spin capacitor. Hybridization at the carbon-metal oxide interface leads to spin-polarized charge trapping after an applied voltage or photocurrent. Strong electronic structure changes, including a 1-eV energy shift and spin polarization in the C60 lowest unoccupied molecular orbital, are then revealed by x-ray absorption spectroscopy, in agreement with density functional theory simulations. Muon spin spectroscopy measurements give further independent evidence of local spin ordering and magnetic moments optically/electronically stored at the heterojunctions. These spin-polarized states dissipate when shorting the electrodes. The spin storage decay time is controlled by magnetic ordering at the interface, leading to coherence times of seconds to hours even at room temperature.
Collapse
Affiliation(s)
- T. Moorsom
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - M. Rogers
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - I. Scivetti
- Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool, Liverpool L69 3BX, England
| | - S. Bandaru
- Beijing Computational Science Research Centre, 100193 Beijing, China
| | - G. Teobaldi
- Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool, Liverpool L69 3BX, England
- Beijing Computational Science Research Centre, 100193 Beijing, China
| | - M. Valvidares
- ALBA Synchrotron Light Source, E-08290 Barcelona, Spain
| | - M. Flokstra
- School of Physics and Astronomy, SUPA, University of St Andrews, St Andrews KY16 9SS, UK
| | - S. Lee
- School of Physics and Astronomy, SUPA, University of St Andrews, St Andrews KY16 9SS, UK
| | - R. Stewart
- School of Physics and Astronomy, SUPA, University of St Andrews, St Andrews KY16 9SS, UK
| | - T. Prokscha
- Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - P. Gargiani
- ALBA Synchrotron Light Source, E-08290 Barcelona, Spain
| | - N. Alosaimi
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - G. Stefanou
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - M. Ali
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - F. Al Ma’Mari
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
- Department of Physics, Sultan Qaboos University, P.O. Box 36, 123 Muscat, Oman
| | - G. Burnell
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - B. J. Hickey
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - O. Cespedes
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| |
Collapse
|
24
|
Yadalam HK, Mitra S, Harbola U. Spontaneous Light Emission from Molecular Junctions: Theoretical Analysis of Upconversion Signal. J Phys Chem A 2019; 123:10594-10598. [PMID: 31718183 DOI: 10.1021/acs.jpca.9b09917] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Spontaneous light emission from a current-carrying molecular junction is analyzed. There are two leading processes, fluorescence and electroluminescence, as defined using Liouville space diagrams within the perturbative method, that contribute to the light emission from junctions. This allows us to identify a general mechanism that explains the origin of the so-called upconversion electroluminescence (UCEL) signal, which has been observed in a variety of molecular junctions [Umera et al. Chem. Phys. Lett. 2007, 448, 232; Dong et al. Nat. Photonics 2010, 4, 50]. Here, we show that a double-peak signal, one at energy less than the applied bias and the other at higher energy (UCEL), is generated due to overlap between two processes: one is electron transfer to create the required excited state, and the other is radiative relaxation of the excited state. The lifetimes induced by the lead interactions play a crucial role in determining the required overlap between these processes. Our analysis shows that, unlike the higher-energy signal, the lower-energy peak is sensitive to the applied bias and does not correspond to any optical resonance in the junction. The signal at higher energy is enhanced as the temperature is increased. We demonstrate our findings using nonperturbative analytic results for a model system.
Collapse
Affiliation(s)
- Hari Kumar Yadalam
- Department of Inorganic and Physical Chemistry , Indian Institute of Science , Bangalore 560012 India
| | - Souvik Mitra
- Department of Inorganic and Physical Chemistry , Indian Institute of Science , Bangalore 560012 India
| | - Upendra Harbola
- Department of Inorganic and Physical Chemistry , Indian Institute of Science , Bangalore 560012 India
| |
Collapse
|
25
|
Parzefall M, Novotny L. Optical antennas driven by quantum tunneling: a key issues review. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2019; 82:112401. [PMID: 31491785 DOI: 10.1088/1361-6633/ab4239] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Analogous to radio- and microwave antennas, optical nanoantennas are devices that receive and emit radiation at optical frequencies. Until recently, the realization of electrically driven optical antennas was an outstanding challenge in nanophotonics. In this review we discuss and analyze recent reports in which quantum tunneling-specifically inelastic electron tunneling-is harnessed as a means to convert electrical energy into photons, mediated by optical antennas. To aid this analysis we introduce the fundamentals of optical antennas and inelastic electron tunneling. Our discussion is focused on recent progress in the field and on future directions and opportunities.
Collapse
|
26
|
Kaiser K, Gross L, Schulz F. A Single-Molecule Chemical Reaction Studied by High-Resolution Atomic Force Microscopy and Scanning Tunneling Microscopy Induced Light Emission. ACS NANO 2019; 13:6947-6954. [PMID: 31184117 PMCID: PMC6595658 DOI: 10.1021/acsnano.9b01852] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Atomic force microscopy (AFM) as well as scanning tunneling microscopy induced light emission (STM-LE) are, each on their own, powerful tools used to investigate a large variety of properties of single molecules adsorbed on a surface. However, accessing both structural information by AFM as well as optical information by STM-LE on the same molecule so far remains elusive. We present a combined high-resolution AFM and STM-LE study on single metal-oxide phthalocyanines. Using atomic manipulation, the molecules can be deliberately reduced. We demonstrate structure elucidation and adsorption geometry determination of single molecules with atomic resolution combined with optical characterization by STM-LE and the possibility of investigating the change in a molecule's exciton emission intensity by a chemical reaction.
Collapse
|
27
|
Luo Y, Chen G, Zhang Y, Zhang L, Yu Y, Kong F, Tian X, Zhang Y, Shan C, Luo Y, Yang J, Sandoghdar V, Dong Z, Hou JG. Electrically Driven Single-Photon Superradiance from Molecular Chains in a Plasmonic Nanocavity. PHYSICAL REVIEW LETTERS 2019; 122:233901. [PMID: 31298910 DOI: 10.1103/physrevlett.122.233901] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Indexed: 05/21/2023]
Abstract
We demonstrate single-photon superradiance from artificially constructed nonbonded zinc-phthalocyanine molecular chains of up to 12 molecules. We excite the system via electron tunneling in a plasmonic nanocavity and quantitatively investigate the interaction of the localized plasmon with single-exciton superradiant states resulting from dipole-dipole coupling. Dumbbell-like patterns obtained by subnanometer resolved spectroscopic imaging disclose the coherent nature of the coupling associated with superradiant states while second-order photon correlation measurements demonstrate single-photon emission. The combination of spatially resolved spectral measurements with theoretical considerations reveals that nanocavity plasmons dramatically modify the linewidth and intensity of emission from the molecular chains, but they do not dictate the intrinsic coherence of the superradiant states. Our studies shed light on the optical properties of molecular collective states and their interaction with nanoscopically localized plasmons.
Collapse
Affiliation(s)
- Yang 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, Anhui 230026, China
| | - Gong Chen
- 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, Anhui 230026, China
- School of Physics and Engineering, Zhengzhou University, Zhengzhou 450052, China
| | - Yang Zhang
- 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, Anhui 230026, China
| | - Li Zhang
- 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, Anhui 230026, China
| | - Yunjie Yu
- 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, Anhui 230026, China
| | - Fanfang Kong
- 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, Anhui 230026, China
| | - Xiaojun Tian
- 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, Anhui 230026, China
| | - Yao Zhang
- 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, Anhui 230026, China
| | - Chongxin Shan
- School of Physics and Engineering, Zhengzhou University, Zhengzhou 450052, 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, Anhui 230026, China
| | - Jinlong Yang
- 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, Anhui 230026, China
| | - Vahid Sandoghdar
- Max Planck Institute for the Science of Light, Erlangen 91058, Germany
| | - Zhenchao Dong
- 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, Anhui 230026, China
| | - J G Hou
- 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, Anhui 230026, China
| |
Collapse
|
28
|
Miwa K, Imada H, Imai-Imada M, Kimura K, Galperin M, Kim Y. Many-Body State Description of Single-Molecule Electroluminescence Driven by a Scanning Tunneling Microscope. NANO LETTERS 2019; 19:2803-2811. [PMID: 30694065 DOI: 10.1021/acs.nanolett.8b04484] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Electron transport and optical properties of a single molecule in contact with conductive materials have attracted considerable attention because of their scientific importance and potential applications. With the recent progress in experimental techniques, especially by virtue of scanning tunneling microscope (STM)-induced light emission, where the tunneling current of the STM is used as an atomic-scale source for induction of light emission from a single molecule, it has become possible to investigate single-molecule properties at subnanometer spatial resolution. Despite extensive experimental studies, the microscopic mechanism of electronic excitation of a single molecule in STM-induced light emission has yet to be clarified. Here we present a formulation of single-molecule electroluminescence driven by electron transfer between a molecule and metal electrodes based on a many-body state representation of the molecule. The effects of intramolecular Coulomb interaction on conductance and luminescence spectra are investigated using the nonequilibrium Hubbard Green's function technique combined with first-principles calculations. We compare simulation results with experimental data and find that the intramolecular Coulomb interaction is crucial for reproducing recent experiments for a single phthalocyanine molecule. The developed theory provides a unified description of the electron transport and optical properties of a single molecule in contact with metal electrodes driven out of equilibrium, and thereby, it contributes to a microscopic understanding of optoelectronic conversion in single molecules on solid surfaces and in nanometer-scale junctions.
Collapse
Affiliation(s)
- Kuniyuki Miwa
- Surface and Interface Science Laboratory , RIKEN , Wako , Saitama 351-0198 , Japan
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Hiroshi Imada
- Surface and Interface Science Laboratory , RIKEN , Wako , Saitama 351-0198 , Japan
| | - Miyabi Imai-Imada
- Surface and Interface Science Laboratory , RIKEN , Wako , Saitama 351-0198 , Japan
- Department of Advanced Materials Science, Graduate School of Frontier Science , The University of Tokyo , Kashiwa , Chiba 277-8651 , Japan
| | - Kensuke Kimura
- Surface and Interface Science Laboratory , RIKEN , Wako , Saitama 351-0198 , Japan
- Department of Advanced Materials Science, Graduate School of Frontier Science , The University of Tokyo , Kashiwa , Chiba 277-8651 , Japan
| | - Michael Galperin
- Department of Chemistry and Biochemistry , University of California, San Diego , La Jolla , California 92093 , United States
| | - Yousoo Kim
- Surface and Interface Science Laboratory , RIKEN , Wako , Saitama 351-0198 , Japan
| |
Collapse
|
29
|
Chen G, Luo Y, Gao H, Jiang J, Yu Y, Zhang L, Zhang Y, Li X, Zhang Z, Dong Z. Spin-Triplet-Mediated Up-Conversion and Crossover Behavior in Single-Molecule Electroluminescence. PHYSICAL REVIEW LETTERS 2019; 122:177401. [PMID: 31107062 DOI: 10.1103/physrevlett.122.177401] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 02/22/2019] [Indexed: 05/24/2023]
Abstract
Scanning-tunneling-microscope-induced light emission serves as a powerful approach in revealing and manipulating the optical properties of molecular species, intermolecular energy transfer, and plasmon-molecule coupling. Earlier studies have established the existence of molecular up-conversion electroluminescence in diverse situations, but the underlying microscopic mechanisms are still under active debate, dominated by intermolecular triplet-triplet annihilation and plasmonic pumping. Here we report on the experimental realization of up-conversion electroluminescence from a prototypical single phthalocyanine molecule, allowing us to unambiguously rule out mechanisms based on intermolecular coupling and also offering unprecedented opportunities to elucidate much richer characteristics unforeseen in previous studies. In particular, the bias-dependent emission intensity displays three distinct regions with different nonlinear current dependences, which can be attributed to crossover behavior caused by the interplay between inelastic electron scattering and carrier-injection processes. We also develop a microscopic description to capture the essential physics involved in up-conversion electroluminescence mediated by a proper intermediate spin-triplet state.
Collapse
Affiliation(s)
- Gong Chen
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
- School of Physics and Engineering, Zhengzhou University, Zhengzhou, Henan 450052, China
| | - Yang Luo
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Hongying Gao
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jun Jiang
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yunjie Yu
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Li Zhang
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yang Zhang
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiaoguang Li
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Zhenyu Zhang
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhenchao Dong
- International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| |
Collapse
|
30
|
Nian LL, Wang Y, Lü JT. On the Fano Line Shape of Single Molecule Electroluminescence Induced by a Scanning Tunneling Microscope. NANO LETTERS 2018; 18:6826-6831. [PMID: 30335393 DOI: 10.1021/acs.nanolett.8b02706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The coupling between molecular exciton and gap plasmons plays a key role in single molecular electroluminescence induced by a scanning tunneling microscope (STM). But it has been difficult to clarify the complex experimental phenomena. By employing the nonequilibrium Green's function method, we propose a general theoretical model to understand the light emission spectrum of single molecule and gap plasmons from an energy transport point of view. The coherent interaction between gap plasmons and molecular exciton leads to a prominent Fano resonance in the emission spectrum. We analyze the dependence of the Fano line shape on the system parameters, based on which we provide a unified account of several recent experimental observations. Moreover, we highlight the effect of the tip-molecule electronic coupling on the spectrum.
Collapse
Affiliation(s)
- Lei-Lei Nian
- School of Physics and Wuhan National High Magnetic Field Center , Huazhong University of Science and Technology , 430074 Wuhan , People's Republic of China
| | - Yongfeng Wang
- Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics , Peking University , 100871 Beijing , People's Republic of China
| | - Jing-Tao Lü
- School of Physics and Wuhan National High Magnetic Field Center , Huazhong University of Science and Technology , 430074 Wuhan , People's Republic of China
| |
Collapse
|
31
|
Lu Y, Chen Y, Xu J, Wang T, Lü JT. Decay channels of gap plasmons in STM tunnel junctions. OPTICS EXPRESS 2018; 26:30444-30455. [PMID: 30469918 DOI: 10.1364/oe.26.030444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 10/11/2018] [Indexed: 06/09/2023]
Abstract
We study the decay of gap plasmons localized between a scanning tunneling microscope tip and metal substrate, excited by inelastic tunneling electrons. The overall excited energy from the tunneling electrons is divided into two categories in the form of resistive dissipation and electromagnetic radiation, which together can further be separated into four diffierent channels, including SPP channel on the tip, SPP channel on the substrate, air mode channel and direct quenching channel. In this work, we study the enhancement factor, i.e. Purcell factor, of the STM tunnel junctions, which are mediated by the nearby metallic structures. We find that the gap plasmon mode is most likely to couple to the SPP channel on the tip, rather than the SPP channel on the substrate or the air mode. The direct quenching in the apex of tip also takes a considerable portion especially in high frequency region, the enhancement factor of direct quenching in the tip is much higher than the direct quenching in the substrate. We adopt four tips with diffierent apex radii, i.e., 1 nm, 5 nm, 10 nm, 20 nm. When the apex size is small, the frequency dependent enhancement factor from the SPPs contribution has a pronounced peak at 1.55 eV, however, as the radius increases, the peak of enhancement factor in the high frequency region appears, the 1.55 eV peak becomes less dominated. This phenomenon can be attributed to the change of tip shape, in the form of mode coupling. Our results also show a relationship between the direct quenching in the substrate and in the tip. With the larger radius of apex, the ratio of these two part of energy approaches 1, which indicate that the energy distribution of direct quenching is sensitive to the shape of the tip-substrate gap.
Collapse
|
32
|
Qiu F, Song C, Li L, Wei Y, Tian G. First-principles study on vibrationally resolved fluorescence of fused 5,15-(diphenyl)-10,20-(dibromo)porphyrin molecule. J Chem Phys 2018; 149:074312. [PMID: 30134706 DOI: 10.1063/1.5036618] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The vibrationally resolved fluorescence spectrum of a narrow-line single-molecule transducer, fused 5,15-(diphenyl)-10,20-(dibromo)porphyrin (fused-H2P) molecule, has been calculated by time-dependent density functional theory with the inclusion of both Franck-Condon and Herzberg-Teller contributions. Analytical transition dipole derivatives are used for the calculations of Herzberg-Teller terms to eliminate the possible errors caused by numerical differentials. The performance of different exchange-correlation functionals including B3LYP, ωB97X-D, and M06-2X has been examined. The comparison with the high-resolution experimental emission spectrum indicates that all three functionals can satisfactorily describe the fluorescence spectral profile, while ωB97X-D and M06-2X give slightly better excitation energy than B3LYP. Detailed analysis shows that the fluorescence spectrum is dominated by the Franck-Condon contribution, while the Herzberg-Teller term contributes mostly to its low energy tail. It is found that the size of the basis set has limited influence on the fluorescence spectrum, and a standard 6-31G(d, p) basis set is adequate for the purpose. The substitution of terthiophene side chains is found to have minor effects on the fluorescence spectrum. Our study provides unambitious assignments for all the vibronic structures in the experimental spectrum.
Collapse
Affiliation(s)
- Feifei Qiu
- Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
| | - Ce Song
- Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm, Sweden
| | - Li Li
- Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
| | - Yong Wei
- Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
| | - Guangjun Tian
- Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China
| |
Collapse
|
33
|
Kröger J, Doppagne B, Scheurer F, Schull G. Fano Description of Single-Hydrocarbon Fluorescence Excited by a Scanning Tunneling Microscope. NANO LETTERS 2018; 18:3407-3413. [PMID: 29719154 DOI: 10.1021/acs.nanolett.8b00304] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The detection of fluorescence with submolecular resolution enables the exploration of spatially varying photon yields and vibronic properties at the single-molecule level. By placing individual polycyclic aromatic hydrocarbon molecules into the plasmon cavity formed by the tip of a scanning tunneling microscope and a NaCl-covered Ag(111) surface, molecular light emission spectra are obtained that unravel vibrational progression. In addition, light spectra unveil a signature of the molecule even when the tunneling current is injected well separated from the molecular emitter. This signature exhibits a distance-dependent Fano profile that reflects the subtle interplay between inelastic tunneling electrons, the molecular exciton and localized plasmons in at-distance as well as on-molecule fluorescence. The presented findings open the path to luminescence of a different class of molecules than investigated before and contribute to the understanding of single-molecule luminescence at surfaces in a unified picture.
Collapse
Affiliation(s)
- Jörg Kröger
- Institut de Physique et Chimie des Matériaux de Strasbourg , Université de Strasbourg, CNRS, IPCMS, UMR 7504 , F-67000 Strasbourg , France
| | - Benjamin Doppagne
- Institut de Physique et Chimie des Matériaux de Strasbourg , Université de Strasbourg, CNRS, IPCMS, UMR 7504 , F-67000 Strasbourg , France
| | - Fabrice Scheurer
- Institut de Physique et Chimie des Matériaux de Strasbourg , Université de Strasbourg, CNRS, IPCMS, UMR 7504 , F-67000 Strasbourg , France
| | - Guillaume Schull
- Institut de Physique et Chimie des Matériaux de Strasbourg , Université de Strasbourg, CNRS, IPCMS, UMR 7504 , F-67000 Strasbourg , France
| |
Collapse
|
34
|
Wang HF, Chen G, Li XG, Dong ZC. Role of nanocavity plasmons in tunneling electron induced light emission on and near a molecule. CHINESE J CHEM PHYS 2018. [DOI: 10.1063/1674-0068/31/cjcp1802024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Hui-fang Wang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
| | - Gong Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
- School of Physics and Engineering, Zhengzhou University, Zhengzhou 450052, China
| | - Xiao-guang Li
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Zhen-chao Dong
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
| |
Collapse
|
35
|
Niu JX, Pan CD, Liu YT, Lou ST, Wu E, Wu BT, Zhang XL, Jin QY. Plasmon-enhanced fluorescence of submonolayer porphyrins by silver-polymer core-shell nanoparticles. OPTICS EXPRESS 2018; 26:3489-3496. [PMID: 29401876 DOI: 10.1364/oe.26.003489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 01/29/2018] [Indexed: 06/07/2023]
Abstract
We investigate the fluorescence from submonolayer porphyrin molecules near silver-polymer core-shell nanoparticles (NPs) at a well-controlled separation distance of about 1 nm - 5 nm. When porphyrin molecules are deposited on silver NPs with the plasmonic resonance peak at about 410 nm, which matches very closely with the 405-nm excitation laser and the absorption band of porphyrin molecules, their emission intensity is found to be enhanced due to the plasmonic resonant excitation enhancement, and shows a decline as the increasing polymer shell thickness. Meanwhile, the lifetime results demonstrate that there exists the fluorescence quenching due to the charge transfer and nonradiative energy transfer losses, which is also the main reason that the maximum enhancement factor obtained in experiment is only about 2.3, although the theoretical one is above 60 according to the electric field distribution near silver NPs calculated by finite-difference time-domain method.
Collapse
|
36
|
Signatures of Plexitonic States in Molecular Electroluminescence. Sci Rep 2018; 8:2314. [PMID: 29396443 PMCID: PMC5797164 DOI: 10.1038/s41598-018-19382-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 12/05/2017] [Indexed: 11/25/2022] Open
Abstract
We develop a quantum master equation (QME) approach to investigate the electroluminesence (EL) of molecules confined between metallic electrodes and coupled to quantum plasmonic modes. Within our general state-based framework, we describe electronic tunneling, vibrational damping, environmental dephasing, and the quantum coherent dynamics of coupled quantum electromagnetic field modes. As an example, we calculate the STM-induced spontaneous emission of a tetraphenylporphyrin (TPP) molecule coupled to a nanocavity plasmon. In the weak molecular exciton-plasmon coupling regime we find excellent agreement with experiments, including above-threshold hot luminescence, an effect not described by previous semiclassical calculations. In the strong coupling regime, we analyze the spectral features indicative of the formation of plexcitonic states.
Collapse
|
37
|
Zhang L, Yu YJ, Chen LG, Luo Y, Yang B, Kong FF, Chen G, Zhang Y, Zhang Q, Luo Y, Yang JL, Dong ZC, Hou JG. Electrically driven single-photon emission from an isolated single molecule. Nat Commun 2017; 8:580. [PMID: 28924226 PMCID: PMC5603600 DOI: 10.1038/s41467-017-00681-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 07/20/2017] [Indexed: 11/09/2022] Open
Abstract
Electrically driven molecular light emitters are considered to be one of the promising candidates as single-photon sources. However, it is yet to be demonstrated that electrically driven single-photon emission can indeed be generated from an isolated single molecule notwithstanding fluorescence quenching and technical challenges. Here, we report such electrically driven single-photon emission from a well-defined single molecule located inside a precisely controlled nanocavity in a scanning tunneling microscope. The effective quenching suppression and nanocavity plasmonic enhancement allow us to achieve intense and stable single-molecule electroluminescence. Second-order photon correlation measurements reveal an evident photon antibunching dip with the single-photon purity down to g(2)(0) = 0.09, unambiguously confirming the single-photon emission nature of the single-molecule electroluminescence. Furthermore, we demonstrate an ultrahigh-density array of identical single-photon emitters. Molecular emitters offer a promising solution for single-photon generation. Here, by exploiting electronic decoupling by an ultrathin dielectric spacer and emission enhancement by a resonant plasmonic nanocavity, the authors demonstrate electrically driven single-photon emission from a single molecule.
Collapse
Affiliation(s)
- Li Zhang
- 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, Anhui, 230026, China
| | - Yun-Jie Yu
- 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, Anhui, 230026, China
| | - Liu-Guo Chen
- 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, Anhui, 230026, China
| | - Yang 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, Anhui, 230026, China
| | - Ben Yang
- 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, Anhui, 230026, China
| | - Fan-Fang Kong
- 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, Anhui, 230026, China
| | - Gong Chen
- 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, Anhui, 230026, China
| | - Yang Zhang
- 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, Anhui, 230026, China.
| | - Qiang Zhang
- 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, Anhui, 230026, 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, Anhui, 230026, China
| | - Jin-Long Yang
- 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, Anhui, 230026, China
| | - Zhen-Chao Dong
- 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, Anhui, 230026, China.
| | - J G Hou
- 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, Anhui, 230026, China.
| |
Collapse
|
38
|
Peters PJ, Xu F, Kaasbjerg K, Rastelli G, Belzig W, Berndt R. Quantum Coherent Multielectron Processes in an Atomic Scale Contact. PHYSICAL REVIEW LETTERS 2017; 119:066803. [PMID: 28949609 DOI: 10.1103/physrevlett.119.066803] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Indexed: 05/13/2023]
Abstract
The light emission from a scanning tunneling microscope operated on a Ag(111) surface at 6 K is analyzed from low conductances to values approaching the conductance quantum. Optical spectra recorded at sample voltages V reveal emission with photon energies hν>2eV. A model of electrons interacting coherently via a localized plasmon-polariton mode reproduces the experimental data, in particular, the kinks in the spectra at eV and 2eV as well as the scaling of the intensity at low and intermediate conductances.
Collapse
Affiliation(s)
- Peter-Jan Peters
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - Fei Xu
- Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany
| | - Kristen Kaasbjerg
- Center for Nanostructured Graphene, Department of Micro- and Nanotechnology, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | | | - Wolfgang Belzig
- Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| |
Collapse
|
39
|
Song C, Li L, Duan S, Luo Y, Tian G. Theoretical simulations for vibrationally-resolved absorption spectra of naphthalenediimide cyclophane derivatives. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 183:339-347. [PMID: 28458239 DOI: 10.1016/j.saa.2017.04.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Revised: 04/14/2017] [Accepted: 04/16/2017] [Indexed: 06/07/2023]
Abstract
In the present work we systematically investigated the vibrationally-resolved absorption spectra of three core substituted naphthalenediimide cyclophane derivatives. It has been performed by time-dependent density functional theory calculations using three different exchange-correlation functionals, including the conventional B3LYP functional and two long-range corrected functionals: CAM-B3LYP and ωB97XD. The solvent effects were also considered with the polarizable continuum model. Calculation results showed that long range corrections are needed to correctly describe the optical properties of the three molecules because of the strong charge transfer characteristic of the excited states. The core substitution induced red shift to the first absorption band is nicely explained by the theoretical calculations. It is found that this band mainly involves the transitions within the core substituted naphthalenediimide chromophore. The high energy absorption band, on the other hand, is generated mainly from the un-substituted chromophore. These characters result in different substitution dependence for those two main absorption bands. Furthermore, the simulated vibrational profiles of the first two absorption bands nicely reproduce the observed vibrational features in the measured spectra. The accuracy of the calculated results from different functionals and basis sets has been discussed.
Collapse
Affiliation(s)
- Ce Song
- College of Science, Yanshan University, Qinhuangdao 066004, China; Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, Stockholm S-106 91, Sweden
| | - Li Li
- College of Science, Yanshan University, Qinhuangdao 066004, China
| | - Sai Duan
- Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, Stockholm S-106 91, Sweden
| | - Yi Luo
- Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, Stockholm S-106 91, Sweden; Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Guangjun Tian
- College of Science, Yanshan University, Qinhuangdao 066004, China.
| |
Collapse
|
40
|
Zhang Y, Meng QS, Zhang L, Luo Y, Yu YJ, Yang B, Zhang Y, Esteban R, Aizpurua J, Luo Y, Yang JL, Dong ZC, Hou JG. Sub-nanometre control of the coherent interaction between a single molecule and a plasmonic nanocavity. Nat Commun 2017; 8:15225. [PMID: 28524881 PMCID: PMC5454454 DOI: 10.1038/ncomms15225] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/06/2017] [Indexed: 01/15/2023] Open
Abstract
The coherent interaction between quantum emitters and photonic modes in cavities underlies many of the current strategies aiming at generating and controlling photonic quantum states. A plasmonic nanocavity provides a powerful solution for reducing the effective mode volumes down to nanometre scale, but spatial control at the atomic scale of the coupling with a single molecular emitter is challenging. Here we demonstrate sub-nanometre spatial control over the coherent coupling between a single molecule and a plasmonic nanocavity in close proximity by monitoring the evolution of Fano lineshapes and photonic Lamb shifts in tunnelling electron-induced luminescence spectra. The evolution of the Fano dips allows the determination of the effective interaction distance of ∼1 nm, coupling strengths reaching ∼15 meV and a giant self-interaction induced photonic Lamb shift of up to ∼3 meV. These results open new pathways to control quantum interference and field–matter interaction at the nanoscale. Assessing the coupling between a plasmonic nanocavity and a single quantum emitter is challenging due to the lack of spatial control at the atomic scale. Here Zhang et al. achieve control with sub-nanometre precision and demonstrate the Fano resonance and Lamb shift at the single-molecule level.
Collapse
Affiliation(s)
- Yao Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.,Materials Physics Center (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, Donostia-San Sebastián 20018, Spain.,Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, Donostia-San Sebastián 20018, Spain
| | - Qiu-Shi Meng
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Li Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yang Luo
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yun-Jie Yu
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Ben Yang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yang Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Ruben Esteban
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, Donostia-San Sebastián 20018, Spain.,IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, Bilbao 48013, Spain
| | - Javier Aizpurua
- Materials Physics Center (CSIC-UPV/EHU), Paseo Manuel de Lardizabal 5, Donostia-San Sebastián 20018, Spain.,Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, Donostia-San Sebastián 20018, Spain
| | - Yi Luo
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Jin-Long Yang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Zhen-Chao Dong
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - J G Hou
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| |
Collapse
|
41
|
Kuhnke K, Große C, Merino P, Kern K. Atomic-Scale Imaging and Spectroscopy of Electroluminescence at Molecular Interfaces. Chem Rev 2017; 117:5174-5222. [DOI: 10.1021/acs.chemrev.6b00645] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Klaus Kuhnke
- Max-Planck-Institut für Festkörperforschung, Stuttgart 70569, Germany
| | - Christoph Große
- Max-Planck-Institut für Festkörperforschung, Stuttgart 70569, Germany
| | - Pablo Merino
- Max-Planck-Institut für Festkörperforschung, Stuttgart 70569, Germany
| | - Klaus Kern
- Max-Planck-Institut für Festkörperforschung, Stuttgart 70569, Germany
- Institut de Physique, Ecole Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| |
Collapse
|
42
|
Große C, Merino P, Rosławska A, Gunnarsson O, Kuhnke K, Kern K. Submolecular Electroluminescence Mapping of Organic Semiconductors. ACS NANO 2017; 11:1230-1237. [PMID: 28085244 DOI: 10.1021/acsnano.6b08471] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The electroluminescence of organic films is the central aspect in organic light emitting diodes (OLEDs) and widely used in current display technology. However, its spatial variation on the molecular scale is essentially unexplored. Here, we address this issue by using scanning tunneling microscopy (STM) and present an in-depth study of the electroluminescence from thin C60 films (<10 monolayers) on Ag(111) and Au(111) surfaces. Similar to an OLED, the metal substrate and STM tip inject complementary charge carriers that may recombine within the molecular film; however, the atomically defined charge injection by the tip enables mapping of the local electroluminescence down to the submolecular scale. We show that the radiative recombination in solid C60 is restricted to various structural defects, whose emission characteristics can be addressed individually. The emission fine structure reveals a coupling to Jahn-Teller active vibrational modes of C60, which implies that its parity-forbidden lowest singlet transition becomes locally allowed at the emission centers. At lateral distances of a few nanometers, only a weak emission from tip-induced plasmons is detectable. Their excitation evidences the injection of both charge carrier types and confirms that they are unable to recombine radiatively at positions far from structural defects. Finally, we demonstrate that the molecular orbital pattern visible in electroluminescence maps enables an unambiguous discrimination between the intrinsic radiative recombination of electron-hole pairs in the organic film and the technique-related emission of tip-induced plasmons. This capability is essential to consolidate STM as a tool to explore the light generation from organic films on the nanoscale.
Collapse
Affiliation(s)
- Christoph Große
- Max-Planck-Institut für Festkörperforschung , Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Pablo Merino
- Max-Planck-Institut für Festkörperforschung , Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Anna Rosławska
- Max-Planck-Institut für Festkörperforschung , Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Olle Gunnarsson
- 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 , 1015 Lausanne, Switzerland
| |
Collapse
|
43
|
Meng Q, Zhang Y, Cai H, Liao Y, Zhang Y, Wang X, Okamoto T, Dong Z. Fabricating two-dimensional plasmonic photonic crystals for the modulation of nanocavity plasmon mode. NANOSCALE 2016; 8:18855-18859. [PMID: 27808322 DOI: 10.1039/c6nr07322k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Here we demonstrate the fabrication of two-dimensional plasmonic photonic crystal (PPC) nanostructures to modulate the nanocavity plasmon (NCP) mode in the scanning tunneling microscope (STM) junction. Theoretically optimized PPC structures with particular defect modes were fabricated and used as the substrates for STM induced luminescence (STML) research. Stable STM imaging and STML studies were achieved by covering a suspended graphene sheet on top of periodic PPC structures. Our preliminary STML results suggest that the NCP emission can be selectively enhanced by the defect mode of the PPC structures, which paves the way for future studies on the engineering of electrically driven single-molecule photon sources and plasmonic lasing through tuning NCP modes.
Collapse
Affiliation(s)
- Qiushi Meng
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Picone A, Giannotti D, Riva M, Calloni A, Bussetti G, Berti G, Duò L, Ciccacci F, Finazzi M, Brambilla A. Controlling the Electronic and Structural Coupling of C 60 Nano Films on Fe(001) through Oxygen Adsorption at the Interface. ACS APPLIED MATERIALS & INTERFACES 2016; 8:26418-26424. [PMID: 27603203 DOI: 10.1021/acsami.6b09641] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
C60 molecules coupled to metals form hybrid systems exploited in a broad range of emerging fields, such as nanoelectronics, spintronics, and photovoltaic solar cells. The electronic coupling at the C60/metal interface plays a crucial role in determining the charge and spin transport in C60-based devices; therefore, a detailed understanding of the interface electronic structure is a prerequisite to engineering the device functionalities. Here, we compare the electronic and structural properties of C60 monolayers interfaced with Fe(001) and oxygen-passivated Fe(001)-p(1 × 1)O substrates. By combining scanning tunneling microscopy and spectroscopy, Auger electron spectroscopy, photoemission and inverse photoemission spectroscopies, we are able to elucidate the striking effect of oxygen on the interaction between Fe(001) and C60. Upon C60 deposition on the oxygen-passivated surface, the oxygen layer remains buried at the C60/Fe(001)-p(1 × 1)O interface, efficiently decoupling the fullerene film from the metallic substrate. Tunneling and photoemission spectroscopies reveal the presence of well-defined molecular resonances for the C60/Fe(001)-p(1 × 1)O system, with a large HOMO-LUMO gap of about 3.4 eV. On the other hand, for the C60/Fe(001) interface, a strong hybridization between the substrate states and the C60 orbitals occurs, resulting in broader molecular resonances.
Collapse
Affiliation(s)
- Andrea Picone
- Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Dario Giannotti
- Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Michele Riva
- Institute of Applied Physics, TU-Wien , Wiedner Hauptstraße 8-10, 1040 Vienna, Austria
| | - Alberto Calloni
- Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Gianlorenzo Bussetti
- Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Giulia Berti
- Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Lamberto Duò
- Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Franco Ciccacci
- Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Marco Finazzi
- Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Alberto Brambilla
- Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| |
Collapse
|
45
|
Meng QS, Cai HB, Lin K, Zhu SE, Liao Y, Zhang Y, Wang XP, Dong ZC. Fabricating Nanogaps between Nanoelectrodes using Dielectrophoresis Technique for Molecular Fluorescence Enhancement. CHINESE J CHEM PHYS 2016. [DOI: 10.1063/1674-0068/29/cjcp1510223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
46
|
Kuang YM, Yu YJ, Luo Y, Zhu JZ, Liao Y, Zhang Y, Dong ZC. Tunneling Electron Induced Fluorescence from Single Porphyrin Molecules Decoupled by Striped-Phase Octanethiol Self-assembled Monolayer. CHINESE J CHEM PHYS 2016. [DOI: 10.1063/1674-0068/29/cjcp1506122] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
47
|
Zhang Y, Luo Y, Zhang Y, Yu YJ, Kuang YM, Zhang L, Meng QS, Luo Y, Yang JL, Dong ZC, Hou JG. Visualizing coherent intermolecular dipole–dipole coupling in real space. Nature 2016; 531:623-7. [DOI: 10.1038/nature17428] [Citation(s) in RCA: 223] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 02/11/2016] [Indexed: 12/29/2022]
|
48
|
Große C, Gunnarsson O, Merino P, Kuhnke K, Kern K. Nanoscale Imaging of Charge Carrier and Exciton Trapping at Structural Defects in Organic Semiconductors. NANO LETTERS 2016; 16:2084-2089. [PMID: 26871739 DOI: 10.1021/acs.nanolett.6b00190] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Charge carrier and exciton trapping in organic semiconductors crucially determine the performance of organic (opto-)electronic devices such as organic field-effect transistors, light-emitting diodes, or solar cells. However, the microscopic origin of the relevant traps generally remains unclear, as most spectroscopic techniques are unable to simultaneously probe the electronic and morphological structure of individual traps. Here, we employ low-temperature scanning tunneling microscopy (STM) and spectroscopy (STS) as well as tight-binding calculations derived from ab initio calculations to image the localized electronic states arising at structural defects in thin C60 films (<10 ML). The spatially and spectrally resolved STM-induced luminescence at these states reveals an enhanced radiative decay of excitons, which is interpreted in terms of the local symmetry lowering and the trapping of excitons by an X-trap. The combined mapping of the STM-induced luminescence, electronic structure, and morphology thus provides new insights into the origin and characteristics of individual exciton traps in organic semiconductors and offers new avenues to study charge carrier and exciton dynamics on molecular scales.
Collapse
Affiliation(s)
- Christoph Große
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Olle Gunnarsson
- Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Pablo Merino
- 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
- École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| |
Collapse
|
49
|
Identifying the Assembly Configuration and Fluorescence Spectra of Nanoscale Zinc-Tetraphenylporphyrin Aggregates with Scanning Tunneling Microscopy. Sci Rep 2016; 6:22756. [PMID: 26948654 PMCID: PMC4780111 DOI: 10.1038/srep22756] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 02/19/2016] [Indexed: 11/23/2022] Open
Abstract
ZnTPP (Zinc-Tetraphenylporphyrin) is one of the most common nanostructured materials, having high stability and excellent optoelectronic properties. In this paper, the fluorescence features of self-assembled ZnTPP monomers and aggregates on Au(111) surface are investigated in detail on the nanometer scale with scanning tunneling microscopy (STM). The formation of ZnTPP dimers is found in thick layers of a layer-by-layer molecular assembly on Au substrate with its specific molecular arrangement well characterized. Tip-induced luminescence shows a red shift from tilted dimers comparing with the behavior from monomers, which can be attributed to the change of vibrational states due to the intermolecular interaction and the increasing dielectric effect. The nanoscale configuration dependence of electroluminescence is demonstrated to provide a powerful tool aiding the design of functional molecular photoelectric devices.
Collapse
|
50
|
Tsai YT, Tseng KP, Chen YF, Wu CC, Fan GL, Wong KT, Wantz G, Hirsch L, Raffy G, Del Guerzo A, Bassani DM. Electroluminescence from Spontaneously Generated Single-Vesicle Aggregates Using Solution-Processed Small Organic Molecules. ACS NANO 2016; 10:998-1006. [PMID: 26730851 DOI: 10.1021/acsnano.5b06261] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Self-assembled aggregates offer great potential for tuning the morphology of organic semiconductors, thereby controlling their size and shape. This is particularly interesting for applications in electroluminescent (EL) devices, but there has been, to date, no reports of a functional EL device in which the size and color of the emissive domains could be controlled using self-assembly. We now report a series of molecules that spontaneously self-organize into small EL domains of sub-micrometer dimensions. By tailoring the emissive chromophores in solution, spherical aggregates that have an average size of 300 nm in diameter and emit any one color, including CIE D65 white, are spontaneously formed in solution. We show that the individual aggregates can be used in EL devices built either using small patterned electrodes or using a sandwich architecture to produce devices emitting in the blue, green, red, and white. Furthermore, sequential deposition of the three primary colors yields an RGB device in which single aggregates of each color are present in close proximity.
Collapse
Affiliation(s)
- Yu-Tang Tsai
- Institute of Molecular Science, CNRS UMR 5255 and University of Bordeaux , F-33405 Talence, France
- IMS, University of Bordeaux, Bordeaux INP, ENSCBP, CNRS UMR 5218 , F-33400 Talence, France
| | - Kuo-Pi Tseng
- Department of Chemistry, National Taiwan University , Taipei 10617, Taiwan
| | - Yan-Fang Chen
- Institute of Molecular Science, CNRS UMR 5255 and University of Bordeaux , F-33405 Talence, France
- IMS, University of Bordeaux, Bordeaux INP, ENSCBP, CNRS UMR 5218 , F-33400 Talence, France
| | - Chung-Chih Wu
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering, Graduate Institute of Photonics and Optoelectronics, and Innovative Photonics Advanced Research Center (i-PARC), National Taiwan University , Taipei 10617, Taiwan
| | - Gang-Lun Fan
- Department of Chemistry, National Taiwan University , Taipei 10617, Taiwan
| | - Ken-Tsung Wong
- Department of Chemistry, National Taiwan University , Taipei 10617, Taiwan
| | - Guillaume Wantz
- IMS, University of Bordeaux, Bordeaux INP, ENSCBP, CNRS UMR 5218 , F-33400 Talence, France
| | - Lionel Hirsch
- IMS, University of Bordeaux, Bordeaux INP, ENSCBP, CNRS UMR 5218 , F-33400 Talence, France
| | - Guillaume Raffy
- Institute of Molecular Science, CNRS UMR 5255 and University of Bordeaux , F-33405 Talence, France
| | - Andre Del Guerzo
- Institute of Molecular Science, CNRS UMR 5255 and University of Bordeaux , F-33405 Talence, France
| | - Dario M Bassani
- Institute of Molecular Science, CNRS UMR 5255 and University of Bordeaux , F-33405 Talence, France
| |
Collapse
|