1
|
Nayak S, Zheng F, Eisfeld A. Near-field scanning optical microscopy of molecular aggregates: The role of light polarization. J Chem Phys 2021; 155:134701. [PMID: 34624996 DOI: 10.1063/5.0064133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We consider theoretically near-field absorption spectra of molecular aggregates stemming from a scattering scanning near-field optical microscopy type setup. Our focus is on the dependence on the direction and polarization of the incoming electromagnetic radiation, which induces a Hertz dipole with a specific orientation at the tip-apex. Within a simple description, which is based on the eigenstates of the aggregate, absorption spectra are calculated for the near field created by this dipole. We find that the spatial patterns of the spectra have a strong dependence on the orientation of this tip-dipole, which can be understood by considering three basic functions that only depend on the arrangement of the aggregate and the molecule tip distance, but not on the orientation of the tip-dipole. This allows direct access to spatial dependence of the aggregate eigenstates. For the important cases of one- and two-dimensional systems with parallel molecules, we discuss these spectra in detail. The simple numerically efficient approach is validated by a more detailed description where the incoming radiation and the interaction between the tip and molecules are explicitly taken into account.
Collapse
Affiliation(s)
- Sidhartha Nayak
- Max-Planck-Institut für Physik Komplexer Systeme, Nöthnitzer Str. 38, D-01187 Dresden, Germany
| | - Fulu Zheng
- Max-Planck-Institut für Physik Komplexer Systeme, Nöthnitzer Str. 38, D-01187 Dresden, Germany
| | - Alexander Eisfeld
- Max-Planck-Institut für Physik Komplexer Systeme, Nöthnitzer Str. 38, D-01187 Dresden, Germany
| |
Collapse
|
2
|
Zheng F, Gao X, Eisfeld A. Excitonic Wave Function Reconstruction from Near-Field Spectra Using Machine Learning Techniques. PHYSICAL REVIEW LETTERS 2019; 123:163202. [PMID: 31702362 DOI: 10.1103/physrevlett.123.163202] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 08/19/2019] [Indexed: 05/26/2023]
Abstract
A general problem in quantum mechanics is the reconstruction of eigenstate wave functions from measured data. In the case of molecular aggregates, information about excitonic eigenstates is vitally important to understand their optical and transport properties. Here we show that from spatially resolved near field spectra it is possible to reconstruct the underlying delocalized aggregate eigenfunctions. Although this high-dimensional nonlinear problem defies standard numerical or analytical approaches, we have found that it can be solved using a convolutional neural network. For both one-dimensional and two-dimensional aggregates we find that the reconstruction is robust to various types of disorder and noise.
Collapse
Affiliation(s)
- Fulu Zheng
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, D-01187 Dresden, Germany
| | - Xing Gao
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, D-01187 Dresden, Germany
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055, USA
| | - Alexander Eisfeld
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Strasse 38, D-01187 Dresden, Germany
| |
Collapse
|
3
|
Eisfeld A, Marquardt C, Paulheim A, Sokolowski M. Superradiance from Two Dimensional Brick-Wall Aggregates of Dye Molecules: The Role of Size and Shape for the Temperature Dependence. PHYSICAL REVIEW LETTERS 2017; 119:097402. [PMID: 28949584 DOI: 10.1103/physrevlett.119.097402] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Indexed: 05/27/2023]
Abstract
Aggregates of interacting molecules can exhibit electronically excited states that are coherently delocalized over many molecules. This can lead to a strong enhancement of the fluorescence decay rate which is referred to as superradiance (SR). To date, the temperature dependence of SR is described by a 1/T law. Using an epitaxial dye layer and a Frenkel-exciton based model we provide both experimental and theoretical evidence that significant deviations from the 1/T behavior can occur for brick-wall-type aggregates of finite size leading even to a maximum of the SR at finite temperature. This is due to the presence of low energy excitations of weak or zero transition strength. These findings are relevant for designing light-emitting molecular materials.
Collapse
Affiliation(s)
- Alexander Eisfeld
- Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Str. 38, D-01187 Dresden, Germany
| | - Christian Marquardt
- Universität Bonn, Institut für Physikalische und Theoretische Chemie, Wegelerstr. 12, 53115 Bonn, Germany
| | - Alexander Paulheim
- Universität Bonn, Institut für Physikalische und Theoretische Chemie, Wegelerstr. 12, 53115 Bonn, Germany
| | - Moritz Sokolowski
- Universität Bonn, Institut für Physikalische und Theoretische Chemie, Wegelerstr. 12, 53115 Bonn, Germany
| |
Collapse
|
4
|
Marquardt C, Paulheim A, Rohbohm N, Merkel R, Sokolowski M. A surface science compatible epifluorescence microscope for inspection of samples under ultra high vacuum and cryogenic conditions. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:083702. [PMID: 28863709 DOI: 10.1063/1.4997953] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We modified an epi-illumination light microscope and mounted it on an ultra high vacuum chamber for investigating samples used in a surface science experiment. For easy access and bake out, all optical components are placed outside the vacuum and the sample is imaged through a glass window. The microscope can be operated in reflection brightfield or epifluorescence mode to image the sample surface or fluorescent dye molecules adsorbed on it. The homemade sample mounting was made compatible for the use under the microscope; sample temperatures as low as 6 K can be achieved. The performance of the microscope is demonstrated on two model samples: Brightfield-images of a well-prepared Ag(100) surface show a macroscopic corrugation of the surface, although low energy electron diffraction data indicate a highly ordered crystalline surface. The surface shows macroscopic protrusions with flat regions, about 20-200 μm in diameter, in between. Fluorescence images of diluted 3,4,9,10-perylene tetracarboxylicacid dianhydride (PTCDA) molecules adsorbed on an ultrathin epitaxial KCl film on the Ag(100) surface show a shading effect at surface protrusions due to an inclined angle of incidence of the PTCDA beam during deposition. For some preparations, the distribution of the fluorescence intensity is inhomogeneous and shows a dense network of bright patches about 5 μm in diameter related to the macroscopic corrugation of the surface. We propose that such a light microscope can aid many surface science experiments, especially those dealing with epitaxial growth or fluorescent materials.
Collapse
Affiliation(s)
- Christian Marquardt
- Institut für Physikalische und Theoretische Chemie der Universität Bonn, Wegelerstrasse 12, 53115 Bonn, Germany
| | - Alexander Paulheim
- Institut für Physikalische und Theoretische Chemie der Universität Bonn, Wegelerstrasse 12, 53115 Bonn, Germany
| | - Nils Rohbohm
- Institut für Physikalische und Theoretische Chemie der Universität Bonn, Wegelerstrasse 12, 53115 Bonn, Germany
| | - Rudolf Merkel
- Institute of Complex Systems, ICS-7: Biomechanics, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Moritz Sokolowski
- Institut für Physikalische und Theoretische Chemie der Universität Bonn, Wegelerstrasse 12, 53115 Bonn, Germany
| |
Collapse
|
5
|
Zhang LJ, Wu SY, Kuang MQ, Hu XF, Li GL. Theoretical studies of the spin Hamiltonian parameters and local structures for Ag2+ in AgCl and KCl crystals. J STRUCT CHEM+ 2017. [DOI: 10.1134/s0022476617040047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
6
|
Dijkstra AG, Duan HG, Knoester J, Nelson KA, Cao J. How two-dimensional brick layer J-aggregates differ from linear ones: Excitonic properties and line broadening mechanisms. J Chem Phys 2016; 144:134310. [DOI: 10.1063/1.4944980] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Arend G. Dijkstra
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149 Bldg. 99, 22761 Hamburg, Germany
| | - Hong-Guang Duan
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149 Bldg. 99, 22761 Hamburg, Germany
| | - Jasper Knoester
- Zernike Institute for Advanced Materials, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Keith A. Nelson
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Jianshu Cao
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| |
Collapse
|
7
|
Paulheim A, Marquardt C, Sokolowski M, Hochheim M, Bredow T, Aldahhak H, Rauls E, Schmidt WG. Surface induced vibrational modes in the fluorescence spectra of PTCDA adsorbed on the KCl(100) and NaCl(100) surfaces. Phys Chem Chem Phys 2016; 18:32891-32902. [DOI: 10.1039/c6cp05661j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report a combined experiment-theory study on low energy vibrational modes in fluorescence spectra of perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTCDA) molecules.
Collapse
Affiliation(s)
- A. Paulheim
- Institut für Physikalische und Theoretische Chemie der Universität Bonn
- 53115 Bonn
- Germany
| | - C. Marquardt
- Institut für Physikalische und Theoretische Chemie der Universität Bonn
- 53115 Bonn
- Germany
| | - M. Sokolowski
- Institut für Physikalische und Theoretische Chemie der Universität Bonn
- 53115 Bonn
- Germany
| | - M. Hochheim
- Mulliken Center for Theoretical Chemistry
- Institut für Physikalische und Theoretische Chemie der Universität Bonn
- 53115 Bonn
- Germany
| | - T. Bredow
- Mulliken Center for Theoretical Chemistry
- Institut für Physikalische und Theoretische Chemie der Universität Bonn
- 53115 Bonn
- Germany
| | - H. Aldahhak
- Lehrstuhl für Theoretische Physik
- Universität Paderborn
- 33098 Paderborn
- Germany
| | - E. Rauls
- Lehrstuhl für Theoretische Physik
- Universität Paderborn
- 33098 Paderborn
- Germany
| | - W. G. Schmidt
- Lehrstuhl für Theoretische Physik
- Universität Paderborn
- 33098 Paderborn
- Germany
| |
Collapse
|
8
|
Rouillé G, Kirchhuebel T, Rink M, Gruenewald M, Kröger J, Forker R, Fritz T. Identification of vibrational excitations and optical transitions of the organic electron donor tetraphenyldibenzoperiflanthene (DBP). Phys Chem Chem Phys 2015; 17:30404-16. [DOI: 10.1039/c5cp03761a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The spectra of DBP grains (IR) and rare-gas-matrix-isolated molecules (UV/vis) are used to analyze HREELS and DRS measurements of DBP molecules adsorbed on Au(111) and mica(0001).
Collapse
Affiliation(s)
- Gaël Rouillé
- Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena
- Institute of Solid State Physics
- 07743 Jena
- Germany
| | - Tino Kirchhuebel
- Institute of Solid State Physics
- Friedrich Schiller University
- 07743 Jena
- Germany
| | - Marcel Rink
- Institut für Physik
- Technische Universität Ilmenau
- 98693 Ilmenau
- Germany
| | - Marco Gruenewald
- Institute of Solid State Physics
- Friedrich Schiller University
- 07743 Jena
- Germany
| | - Jörg Kröger
- Institut für Physik
- Technische Universität Ilmenau
- 98693 Ilmenau
- Germany
| | - Roman Forker
- Institute of Solid State Physics
- Friedrich Schiller University
- 07743 Jena
- Germany
| | - Torsten Fritz
- Institute of Solid State Physics
- Friedrich Schiller University
- 07743 Jena
- Germany
| |
Collapse
|
9
|
Müller M, Paulheim A, Eisfeld A, Sokolowski M. Finite size line broadening and superradiance of optical transitions in two dimensional long-range ordered molecular aggregates. J Chem Phys 2013; 139:044302. [DOI: 10.1063/1.4813521] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
|
10
|
Paulheim A, Müller M, Marquardt C, Sokolowski M. Fluorescence spectroscopy of PTCDA molecules on the KCl(100) surface in the limit of low coverages: site selection and diffusion. Phys Chem Chem Phys 2013; 15:4906-13. [DOI: 10.1039/c3cp44256j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|