1
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Rosławska A, Kaiser K, Romeo M, Devaux E, Scheurer F, Berciaud S, Neuman T, Schull G. Submolecular-scale control of phototautomerization. NATURE NANOTECHNOLOGY 2024; 19:738-743. [PMID: 38413791 DOI: 10.1038/s41565-024-01622-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 01/29/2024] [Indexed: 02/29/2024]
Abstract
Optically activated reactions initiate biological processes such as photosynthesis or vision, but can also control polymerization, catalysis or energy conversion. Methods relying on the manipulation of light at macroscopic and mesoscopic scales are used to control on-surface photochemistry, but do not offer atomic-scale control. Here we take advantage of the confinement of the electromagnetic field at the apex of a scanning tunnelling microscope tip to drive the phototautomerization of a free-base phthalocyanine with submolecular precision. We can control the reaction rate and the relative tautomer population through a change in the laser excitation wavelength or through the tip position. Atomically resolved tip-enhanced photoluminescence spectroscopy and hyperspectral mapping unravel an excited-state mediated process, which is quantitatively supported by a comprehensive theoretical model combining ab initio calculations with a parametric open-quantum-system approach. Our experimental strategy may allow insights in other photochemical reactions and proof useful to control complex on-surface reactions.
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Affiliation(s)
- Anna Rosławska
- Université de Strasbourg, CNRS, IPCMS, Strasbourg, France.
- Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany.
| | - Katharina Kaiser
- Université de Strasbourg, CNRS, IPCMS, Strasbourg, France
- 4th Physical Institute - Solids and Nanostructures, Georg-August-Universität Göttingen, Göttingen, Germany
| | | | - Eloïse Devaux
- Université de Strasbourg, CNRS, ISIS, Strasbourg, France
| | | | | | - Tomáš Neuman
- Institut des Sciences Moléculaires d'Orsay (ISMO), UMR 8214, CNRS, Université Paris-Saclay, Orsay, France.
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic.
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2
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Hung TC, Godinez-Loyola Y, Steinbrecher M, Kiraly B, Khajetoorians AA, Doltsinis NL, Strassert CA, Wegner D. Activating the Fluorescence of a Ni(II) Complex by Energy Transfer. J Am Chem Soc 2024; 146:8858-8864. [PMID: 38513215 PMCID: PMC10996004 DOI: 10.1021/jacs.3c07716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 03/07/2024] [Accepted: 03/07/2024] [Indexed: 03/23/2024]
Abstract
Luminescence of open-shell 3d metal complexes is often quenched due to ultrafast intersystem crossing (ISC) and cooling into a dark metal-centered excited state. We demonstrate successful activation of fluorescence from individual nickel phthalocyanine (NiPc) molecules in the junction of a scanning tunneling microscope (STM) by resonant energy transfer from other metal phthalocyanines at low temperature. By combining STM, scanning tunneling spectroscopy, STM-induced luminescence, and photoluminescence experiments as well as time-dependent density functional theory, we provide evidence that there is an activation barrier for the ISC, which, in most experimental conditions, is overcome. We show that this is also the case in an electroluminescent tunnel junction where individual NiPc molecules adsorbed on an ultrathin NaCl decoupling film on a Ag(111) substrate are probed. However, when an MPc (M = Zn, Pd, Pt) molecule is placed close to NiPc by means of STM atomic manipulation, resonant energy transfer can excite NiPc without overcoming the ISC activation barrier, leading to Q-band fluorescence. This work demonstrates that the thermally activated population of dark metal-centered states can be avoided by a designed local environment at low temperatures paired with directed molecular excitation into vibrationally cold electronic states. Thus, we can envisage the use of luminophores based on more abundant transition metal complexes that do not rely on Pt or Ir by restricting vibration-induced ISC.
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Affiliation(s)
- Tzu-Chao Hung
- Institute
for Molecules and Materials, Radboud University, 6500 GL Nijmegen, The Netherlands
- Institute
for Experimental and Applied Physics, University of Regensburg, 93040 Regensburg, Germany
| | - Yokari Godinez-Loyola
- Institut
für Anorganische und Analytische Chemie, University of Münster, 48149 Münster, Germany
- Center
for Nanotechnology (CeNTech), University
of Münster, 48149 Münster, Germany
| | - Manuel Steinbrecher
- Institute
for Molecules and Materials, Radboud University, 6500 GL Nijmegen, The Netherlands
| | - Brian Kiraly
- Institute
for Molecules and Materials, Radboud University, 6500 GL Nijmegen, The Netherlands
| | | | - Nikos L. Doltsinis
- Institut
für Festkörpertheorie and Center for Multiscale Theory
and Computation, University of Münster, 48149 Münster, Germany
| | - Cristian A. Strassert
- Institut
für Anorganische und Analytische Chemie, University of Münster, 48149 Münster, Germany
- Center
for Nanotechnology (CeNTech), University
of Münster, 48149 Münster, Germany
- Cells in
Motion Interfaculty Centre (CiMIC) and Center for Soft Nanoscience
(SoN), University of Münster, 48149 Münster, Germany
| | - Daniel Wegner
- Institute
for Molecules and Materials, Radboud University, 6500 GL Nijmegen, The Netherlands
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3
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Brill L, Brandhoff J, Gruenewald M, Calcinelli F, Hofmann OT, Forker R, Fritz T. Partial restoration of aromaticity of pentacene-5,7,12,14-tetrone on Cu(111). NANOSCALE 2024; 16:2654-2661. [PMID: 38230573 PMCID: PMC10832359 DOI: 10.1039/d3nr04848a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 01/04/2024] [Indexed: 01/18/2024]
Abstract
The π-conjugation of organic molecules can be strongly influenced when functional groups are added to a molecule, for example when pentacene is converted into pentacene-5,7,12,14-tetrone (P4O) by substitution of four H-atoms with four O-atoms, leading to four CO double bonds. In fact, although free P4O resembles the parent hydrocarbon pentacene structurally at a first glance, its electronic properties differ drastically and can be more accurately described by three benzene units connected via four carbonyl groups. If P4O is deposited onto Cu(111), the electronic interaction across the interface has previously been reported to fully restore the π-conjugation through a weakening of the CO double bonds and a redistribution of electrons, both of which have been explained with the model of surface-induced aromatic stabilization. Here, we observe for the case of P4O on Cu(111) that the molecule does not exhibit full π-conjugation upon interaction with the surface, likely because of the special electronic nature of the hybridized P4O on Cu(111). Our results are derived from CO-functionalized noncontact atomic force microscopy measurements in combination with dispersion-corrected density functional theory calculations yielding bond lengths and molecular geometries. To characterize the aromaticity, we apply the harmonic oscillator model of aromaticity.
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Affiliation(s)
- Lorenz Brill
- Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 5, 07743 Jena, Germany.
| | - Jonas Brandhoff
- Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 5, 07743 Jena, Germany.
| | - Marco Gruenewald
- Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 5, 07743 Jena, Germany.
| | - Fabio Calcinelli
- Graz University of Technology, Institute of Solid State Physics, NAWI Graz, Petersgasse 16/II, 8010 Graz, Austria.
| | - Oliver T Hofmann
- Graz University of Technology, Institute of Solid State Physics, NAWI Graz, Petersgasse 16/II, 8010 Graz, Austria.
| | - Roman Forker
- Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 5, 07743 Jena, Germany.
| | - Torsten Fritz
- Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 5, 07743 Jena, Germany.
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4
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Riemann A, Rankin L, Henry D. Atomic Charge Dependency of Spiropyran/Merocyanine Adsorption as a Precursor to Surface Isomerization Reactions. ACS OMEGA 2024; 9:798-810. [PMID: 38222550 PMCID: PMC10785610 DOI: 10.1021/acsomega.3c06712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/29/2023] [Accepted: 12/11/2023] [Indexed: 01/16/2024]
Abstract
This computational study investigates the adsorption of various spiropyran and merocyanine isomers on a NaCl substrate using a combination of density functional theory (DFT) and molecular mechanics (MM) calculations. Four different charge methods were used to determine the partial atomic charges for the adsorbate molecules, including Mulliken population analysis and three electrostatic potential (ESP) methods (Merz-Kollman, ChelpG, and Hu-Lu-Yang), while three different force fields (AMBER 3, CHARMM 27, and MM+) were employed for the MM calculations. The results show that the various DFT charge methods produced similar outcomes for the molecules' partial atomic charges, with some exceptions for individual atoms and methods. Additionally, it was found that the ESP charge methods were more sensitive to the conformer orientation than the Mulliken approach. The adsorption behavior of merocyanine conformers with the central bond in trans orientation (T-conformers) was similar for various configurations, with the molecule adsorbing mostly flat with its aromatic rings almost parallel to the substrate. However, C-conformers (with their central bond in cis orientation) and spiropyran isomers exhibited inconsistent adsorption behavior, mostly because only some of the aromatic rings contributed to the adsorption behavior. Due to additional van der Waals interactions of more aromatic rings, the adsorption energies for T-conformers are consistently 0.2-0.3 eV higher than for C-conformers and for spiropyran. The study found that the adsorption geometries and energies of stable T-conformers were independent of the partial atomic charge scheme and force field used, and C-conformers show parameter-dependent behavior upon adsorption, leading to metastable configurations. These findings indicate viable pathways during the spiropyran-merocyanine isomerization reactions. Therefore, the results provide initial insights into the possibility of switching spiropyran isomers into merocyanine isomers and vice versa after adsorption onto substrates.
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Affiliation(s)
- Andreas Riemann
- Department of Physics & Astronomy, Western Washington University, 516 High Street, Bellingham, Washington 98225, United States
| | - Lauren Rankin
- Department of Physics & Astronomy, Western Washington University, 516 High Street, Bellingham, Washington 98225, United States
| | - Dylan Henry
- Department of Physics & Astronomy, Western Washington University, 516 High Street, Bellingham, Washington 98225, United States
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5
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Jiang S, Neuman T, Bretel R, Boeglin A, Scheurer F, Le Moal E, Schull G. Many-Body Description of STM-Induced Fluorescence of Charged Molecules. PHYSICAL REVIEW LETTERS 2023; 130:126202. [PMID: 37027885 DOI: 10.1103/physrevlett.130.126202] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 01/30/2023] [Indexed: 06/19/2023]
Abstract
A scanning tunneling microscope is used to study the fluorescence of a model charged molecule (quinacridone) adsorbed on a sodium chloride (NaCl)-covered metallic sample. Fluorescence from the neutral and positively charged species is reported and imaged using hyperresolved fluorescence microscopy. A many-body model is established based on a detailed analysis of voltage, current, and spatial dependences of the fluorescence and electron transport features. This model reveals that quinacridone adopts a palette of charge states, transient or not, depending on the voltage used and the nature of the underlying substrate. This model has a universal character and clarifies the transport and fluorescence mechanisms of molecules adsorbed on thin insulators.
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Affiliation(s)
- Song Jiang
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Tomáš Neuman
- Institut des Sciences Moléculaires d'Orsay (ISMO), UMR 8214, CNRS, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Rémi Bretel
- Institut des Sciences Moléculaires d'Orsay (ISMO), UMR 8214, CNRS, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Alex Boeglin
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Fabrice Scheurer
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
| | - Eric Le Moal
- Institut des Sciences Moléculaires d'Orsay (ISMO), UMR 8214, CNRS, Université Paris-Saclay, 91405 Orsay Cedex, France
| | - Guillaume Schull
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
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6
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Krukowski P, Hattori T, Akai-Kasaya M, Saito A, Osuga H, Kuwahara Y. Light Emission from M-Type Enantiomer of 2,13-bis(hydroxymethyl)[7]-thiaheterohelicene Molecules Adsorbed on Au(111) and C 60/Au(111) Surfaces Investigated by STM-LE. Int J Mol Sci 2022; 23:ijms232315399. [PMID: 36499724 PMCID: PMC9737099 DOI: 10.3390/ijms232315399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/26/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Light emission from the M-type enantiomer of a helicene derivative (2,13-bis(hydroxymethyl)[7]-thiaheterohelicene) adsorbed on the clean Au(111) and the C60-covered Au(111) surfaces were investigated by tunneling-current-induced light-emission technique. Plasmon-originated light emission was observed on the helicence/Au(111) surface and it was strongly suppressed on the area where the helicene molecules were adsorbed at the edges of the Au(111) terraces. To avoid luminescence quenching of excited helicene molecules and to suppress strong plasmon light emission from the Au(111) surface, C60 layers were used as decoupling buffer layers between helicene molecules and the Au(111) surface. Helicene molecules were adsorbed preferentially on the Au(111) surface rather than on the C60 buffer layers due to the small interaction of the molecules and C60 islands. This fact motivated us to deposit a multilayer of helicene molecules onto the C60 layers grown on the Au(111) surface, leading to the fact that the helicene/C60 multilayer showed strong luminescence with the molecules character. We consider that such strong light emission from the multilayer of helicene molecules has a plasmon origin strongly modulated by the molecular electronic states of (M)-[7]TH-diol molecules.
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Affiliation(s)
- Paweł Krukowski
- Department of Solid State Physics, Faculty of Physics and Applied Informatics, University of Lodz, 90–236 Łódź, Poland
- Correspondence:
| | - Takuma Hattori
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, Suita 565–0871, Japan
| | - Megumi Akai-Kasaya
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, Suita 565–0871, Japan
| | - Akira Saito
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, Suita 565–0871, Japan
| | - Hideji Osuga
- Department of Materials Science and Chemistry, Faculty of Systems Engineering, Wakayama University, Wakayama 640-8510, Japan
| | - Yuji Kuwahara
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, Suita 565–0871, Japan
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7
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Ekar J, Kovač J. AFM Study of Roughness Development during ToF-SIMS Depth Profiling of Multilayers with a Cs + Ion Beam in a H 2 Atmosphere. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:12871-12880. [PMID: 36239688 PMCID: PMC9609309 DOI: 10.1021/acs.langmuir.2c01837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 10/04/2022] [Indexed: 06/16/2023]
Abstract
The influence of H2 flooding on the development of surface roughness during time-of-flight secondary ion mass spectrometry (ToF-SIMS) depth profiling was studied to evaluate the different aspects of a H2 atmosphere in comparison to an ultrahigh vacuum (UHV) environment. Multilayer samples, consisting of different combinations of metal, metal oxide, and alloy layers of different elements, were bombarded with 1 and 2 keV Cs+ ion beams in UHV and a H2 atmosphere of 7 × 10-7 mbar. The surface roughness Sa was measured with atomic force microscopy (AFM) on the initial surface and in the craters formed while sputtering, either in the middle of the layers or at the interfaces. We found that the roughness after Cs+ sputtering depends on the chemical composition/structure of the individual layers, and it increases with the sputtering depth. However, the increase in the roughness was, in specific cases, approximately a few tens of percent lower when sputtering in the H2 atmosphere compared to the UHV. In the other cases, the average surface roughness was generally still lower when H2 flooding was applied, but the differences were statistically insignificant. Additionally, we observed that for the initially rough surfaces with an Sa of about 5 nm, sputtering with the 1 keV Cs+ beam might have a smoothing effect, thereby reducing the initial roughness. Our observations also indicate that Cs+ sputtering with ion energies of 1 and 2 keV has a similar effect on roughness development, except for the cases with initially very smooth samples. The results show the beneficial effect of H2 flooding on surface roughness development during the ToF-SIMS depth profiling in addition to a reduction of the matrix effect and an improved identification of thin layers.
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Affiliation(s)
- Jernej Ekar
- Jožef
Stefan Institute, Jamova Cesta 39, SI-1000 Ljubljana, Slovenia
- Jožef
Stefan International Postgraduate School, Jamova Cesta 39, SI-1000 Ljubljana, Slovenia
| | - Janez Kovač
- Jožef
Stefan Institute, Jamova Cesta 39, SI-1000 Ljubljana, Slovenia
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8
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Ahn Y, Park M, Seo D. Observation of reactions in single molecules/nanoparticles using light microscopy. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yongdeok Ahn
- Department of Chemistry and Physics DGIST Daegu Republic of Korea
| | - Minsoo Park
- Department of Chemistry and Physics DGIST Daegu Republic of Korea
| | - Daeha Seo
- Department of Chemistry and Physics DGIST Daegu Republic of Korea
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9
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Debnath S, Haupa KA, Lebedkin S, Strelnikov D, Kappes MM. Triggering near‐infrared luminescence of vanadyl phthalocyanine by charging. Angew Chem Int Ed Engl 2022; 61:e202201577. [PMID: 35349208 PMCID: PMC9322020 DOI: 10.1002/anie.202201577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Indexed: 11/17/2022]
Abstract
Probing electrofluorochromism (EFC) at the molecular level remains challenging. Here we study the strongly charge state‐dependent photoluminescence of vanadyl phthalocyanine. We report vibrationally resolved absorption and laser‐induced fluorescence (LIF) spectra of samples comprising both the mass‐selected neutral molecule (VOPc⋅, a stable radical) and its cation produced upon electron ionization (EI) isolated in 5 K neon matrices. Ionization of the essentially non‐emissive VOPc⋅ forms a high‐spin diradical cation (VOPc+..) which shows profound photoluminescence (PL) in the NIR range. This unique phenomenon is potentially of interest for NIR‐emitting electro‐optic devices.
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Affiliation(s)
- Sreekanta Debnath
- Institute of Physical Chemistry II Karlsruhe Institute of Technology Fritz-Haber-Weg 2 76131 Karlsruhe Germany
| | - Karolina A. Haupa
- Institute of Physical Chemistry II Karlsruhe Institute of Technology Fritz-Haber-Weg 2 76131 Karlsruhe Germany
| | - Sergei Lebedkin
- Institute of Nanotechnology Karlsruhe Institute of Technology Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Dmitry Strelnikov
- Institute of Physical Chemistry II Karlsruhe Institute of Technology Fritz-Haber-Weg 2 76131 Karlsruhe Germany
| | - Manfred M. Kappes
- Institute of Physical Chemistry II Karlsruhe Institute of Technology Fritz-Haber-Weg 2 76131 Karlsruhe Germany
- Institute of Nanotechnology Karlsruhe Institute of Technology Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
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10
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Debnath S, Haupa KA, Lebedkin S, Strelnikov D, Kappes MM. Triggering near‐infrared luminescence of vanadyl phthalocyanine by charging. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202201577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sreekanta Debnath
- Institute of Physical Chemistry II Karlsruhe Institute of Technology Fritz-Haber-Weg 2 76131 Karlsruhe Germany
| | - Karolina A. Haupa
- Institute of Physical Chemistry II Karlsruhe Institute of Technology Fritz-Haber-Weg 2 76131 Karlsruhe Germany
| | - Sergei Lebedkin
- Institute of Nanotechnology Karlsruhe Institute of Technology Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
| | - Dmitry Strelnikov
- Institute of Physical Chemistry II Karlsruhe Institute of Technology Fritz-Haber-Weg 2 76131 Karlsruhe Germany
| | - Manfred M. Kappes
- Institute of Physical Chemistry II Karlsruhe Institute of Technology Fritz-Haber-Weg 2 76131 Karlsruhe Germany
- Institute of Nanotechnology Karlsruhe Institute of Technology Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Germany
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11
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Vasilev K, Doppagne B, Neuman T, Rosławska A, Bulou H, Boeglin A, Scheurer F, Schull G. Internal Stark effect of single-molecule fluorescence. Nat Commun 2022; 13:677. [PMID: 35115513 PMCID: PMC8813982 DOI: 10.1038/s41467-022-28241-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 01/07/2022] [Indexed: 12/04/2022] Open
Abstract
The optical properties of chromophores can be efficiently tuned by electrostatic fields generated in their close environment, a phenomenon that plays a central role for the optimization of complex functions within living organisms where it is known as internal Stark effect (ISE). Here, we realised an ISE experiment at the lowest possible scale, by monitoring the Stark shift generated by charges confined within a single chromophore on its emission energy. To this end, a scanning tunneling microscope (STM) functioning at cryogenic temperatures is used to sequentially remove the two central protons of a free-base phthalocyanine chromophore deposited on a NaCl-covered Ag(111) surface. STM-induced fluorescence measurements reveal spectral shifts that are associated to the electrostatic field generated by the internal charges remaining in the chromophores upon deprotonation. The internal Stark effect, a shift of the spectral lines of a chromophore induced by electrostatic fields in its close environment, plays an important role in nature. Here the authors observe a Stark shift in the fluorescence spectrum of a phthalocyanine molecule upon charge modifications within the molecule itself, achieved by sequential removal of the central protons with a STM tip.
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Affiliation(s)
- Kirill Vasilev
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000, Strasbourg, France
| | - Benjamin Doppagne
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000, Strasbourg, France
| | - Tomáš Neuman
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000, Strasbourg, France
| | - Anna Rosławska
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000, Strasbourg, France
| | - Hervé Bulou
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000, Strasbourg, France
| | - Alex Boeglin
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000, Strasbourg, France
| | - Fabrice Scheurer
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000, Strasbourg, France
| | - Guillaume Schull
- Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000, Strasbourg, France.
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12
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Mena-Giraldo P, Orozco J. Polymeric Micro/Nanocarriers and Motors for Cargo Transport and Phototriggered Delivery. Polymers (Basel) 2021; 13:3920. [PMID: 34833219 PMCID: PMC8621231 DOI: 10.3390/polym13223920] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 02/07/2023] Open
Abstract
Smart polymer-based micro/nanoassemblies have emerged as a promising alternative for transporting and delivering a myriad of cargo. Cargo encapsulation into (or linked to) polymeric micro/nanocarrier (PC) strategies may help to conserve cargo activity and functionality when interacting with its surroundings in its journey to the target. PCs for cargo phototriggering allow for excellent spatiotemporal control via irradiation as an external stimulus, thus regulating the delivery kinetics of cargo and potentially increasing its therapeutic effect. Micromotors based on PCs offer an accelerated cargo-medium interaction for biomedical, environmental, and many other applications. This review collects the recent achievements in PC development based on nanomicelles, nanospheres, and nanopolymersomes, among others, with enhanced properties to increase cargo protection and cargo release efficiency triggered by ultraviolet (UV) and near-infrared (NIR) irradiation, including light-stimulated polymeric micromotors for propulsion, cargo transport, biosensing, and photo-thermal therapy. We emphasize the challenges of positioning PCs as drug delivery systems, as well as the outstanding opportunities of light-stimulated polymeric micromotors for practical applications.
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Affiliation(s)
| | - Jahir Orozco
- Max Planck Tandem Group in Nanobioengineering, Institute of Chemistry, Faculty of Natural and Exact Sciences, University of Antioquia, Complejo Ruta N, Calle 67 # 52-20, Medellin 050010, Colombia;
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13
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Adsorption and desorption mechanisms on graphene oxide nanosheets: Kinetics and tuning. Innovation (N Y) 2021; 2:100137. [PMID: 34557777 PMCID: PMC8454550 DOI: 10.1016/j.xinn.2021.100137] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 06/15/2021] [Indexed: 02/07/2023] Open
Abstract
A knowledge of the adsorption and desorption behavior of sorbates on surface adsorptive site (SAS) is the key to optimizing the chemical reactivity of catalysts. However, direct identification of the chemical reactivity of SASs is still a challenge due to the limitations of characterization techniques. Here, we present a new pathway to determine the kinetics of adsorption/desorption on SASs of graphene oxide (GO) based on total internal reflectance fluorescence microscopy. The switching on and off of the fluorescent signal of SAS lit by carbon dots (CDs) was used to trace the adsorption process and desorption process. We find that sodium pyrophosphate (PPi) could increase the adsorption equilibrium of CDs thermodynamically and promote the substrate-assisted desorption pathway kinetically. At the single turnover level, it was disclosed that the species that can promote desorption may also be an adsorption promoter. Such discovery provides significant guidance for improving the chemical reactivity of the heterogeneous catalyst. The kinetics of adsorption and desorption process were revealed, respectively, by monitoring a fluorogenic process of carbon dots on the surface of graphene oxides at the single turnover level By regulating the equilibrium of adsorption and desorption, a mechanism for the simultaneous promotion of adsorption and desorption has been discovered A desorption accelerator could play a satisfactory double action, i.e., adsorption promoter on thermodynamics and desorption promoter on kinetics
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14
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Mallada B, Błoński P, Langer R, Jelínek P, Otyepka M, de la Torre B. On-Surface Synthesis of One-Dimensional Coordination Polymers with Tailored Magnetic Anisotropy. ACS APPLIED MATERIALS & INTERFACES 2021; 13:32393-32401. [PMID: 34227386 DOI: 10.1021/acsami.1c04693] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
One-dimensional (1D) metalloporphyrin polymers can exhibit magnetism, depending on the central metal ion and the surrounding ligand field. The possibility of tailoring the magnetic signal in such nanostructures is highly desirable for potential spintronic devices. We present low-temperature (4.2 K) scanning tunneling microscopy and spectroscopy (LT-STM/STS) in combination with high-resolution atomic force microscopy (AFM) and a density functional theory (DFT) study of a two-step synthetic protocol to grow a robust Fe-porphyrin-based 1D polymer on-surface and to tune its magnetic properties. A thermally assisted Ullmann-like coupling reaction of Fe(III)diphenyl-bromine-porphyrin (2BrFeDPP-Cl) on Au(111) in ultra-high vacuum results in long (up to 50 nm) 1D metal-organic wires with regularly distributed magnetic and (electronically) independent porphyrins units, as confirmed by STM images. Thermally controlled C-H bond activation leads to conformational changes in the porphyrin units, which results in molecular planarization steered by 2D surface confinement, as confirmed by high-resolution AFM images. Spin-flip STS images in combination with DFT self-consistent spin-orbit coupling calculations of porphyrin units with different structural conformations reveal that the magnetic anisotropy of the triplet ground state of the central Fe ion units drops down substantially upon intramolecular rearrangements. These results point out to new opportunities for realizing and studying well-defined 1D organic magnets on surfaces and demonstrate the feasibility of tailoring their magnetic properties.
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Affiliation(s)
- Benjamin Mallada
- Regional Centre of Advanced Technologies and Material, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 783 71 Olomouc, Czech Republic
- Institute of Physics, The Czech Academy of Sciences, Cukrovarnická 10, 162 00 Prague, Czech Republic
| | - Piotr Błoński
- Regional Centre of Advanced Technologies and Material, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 783 71 Olomouc, Czech Republic
| | - Rostislav Langer
- Regional Centre of Advanced Technologies and Material, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 783 71 Olomouc, Czech Republic
- Department of Physical Chemistry, Faculty of Science, Palacký University Olomouc, 78371 Olomouc, Czech Republic
| | - Pavel Jelínek
- Regional Centre of Advanced Technologies and Material, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 783 71 Olomouc, Czech Republic
- Institute of Physics, The Czech Academy of Sciences, Cukrovarnická 10, 162 00 Prague, Czech Republic
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Material, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 783 71 Olomouc, Czech Republic
- IT4Innovations, Technical University of Ostrava, 17. listopadu 2172/15, 708 00 Ostrava-Poruba,Czech Republic
| | - Bruno de la Torre
- Regional Centre of Advanced Technologies and Material, Czech Advanced Technology and Research Institute (CATRIN), Palacký University Olomouc, 783 71 Olomouc, Czech Republic
- Institute of Physics, The Czech Academy of Sciences, Cukrovarnická 10, 162 00 Prague, Czech Republic
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15
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Fukuzumi R, Buerkle M, Li Y, Kaneko S, Li P, Kobayashi S, Fujii S, Kiguchi M, Nakamura H, Tsukagoshi K, Nishino T. Water Splitting Induced by Visible Light at a Copper-Based Single-Molecule Junction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2008109. [PMID: 34089231 DOI: 10.1002/smll.202008109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 04/19/2021] [Indexed: 06/12/2023]
Abstract
Water splitting is an essential process for converting light energy into easily storable energy in the form of hydrogen. As environmentally preferable catalysts, Cu-based materials have attracted attention as water-splitting catalysts. To enhance the efficiency of water splitting, a reaction process should be developed. Single-molecule junctions (SMJs) are attractive structures for developing these reactions because the molecule electronic state is significantly modulated, and characteristic electromagnetic effects can be expected. Here, water splitting is induced at Cu-based SMJ and the produced hydrogen is characterized at a single-molecule scale by employing electron transport measurements. After visible light irradiation, the conductance states originate from Cu/hydrogen molecule/Cu junctions, while before irradiation, only Cu/water molecule/Cu junctions were observed. The vibration spectra obtained from inelastic electron tunneling spectroscopy combined with the first-principles calculations reveal that the water molecule trapped between the Cu electrodes is decomposed and that hydrogen is produced. Time-dependent and wavelength-dependent measurements show that localized-surface plasmon decomposes the water molecule in the vicinity of the junction. These findings indicate the potential ability of Cu-based materials for photocatalysis.
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Affiliation(s)
- Risa Fukuzumi
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Marius Buerkle
- CD-FMat, National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono 1-1-1, Tsukuba, Ibaraki, 305-8568, Japan
| | - Yu Li
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Satoshi Kaneko
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Peihui Li
- Institute of Modern Optics, Nankai University, 94 Weijin Road, Tianjin, 300350, P. R. China
| | - Shuji Kobayashi
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Shintaro Fujii
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Manabu Kiguchi
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
| | - Hisao Nakamura
- CD-FMat, National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono 1-1-1, Tsukuba, Ibaraki, 305-8568, Japan
| | - Kazuhito Tsukagoshi
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan
| | - Tomoaki Nishino
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8551, Japan
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16
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Hung TC, Kiraly B, Strik JH, Khajetoorians AA, Wegner D. Plasmon-Driven Motion of an Individual Molecule. NANO LETTERS 2021; 21:5006-5012. [PMID: 34061553 PMCID: PMC8227484 DOI: 10.1021/acs.nanolett.1c00788] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 05/19/2021] [Indexed: 06/12/2023]
Abstract
We demonstrate that nanocavity plasmons generated a few nanometers away from a molecule can induce molecular motion. For this, we study the well-known rapid shuttling motion of zinc phthalocyanine molecules adsorbed on ultrathin NaCl films by combining scanning tunneling microscopy (STM) and spectroscopy (STS) with STM-induced light emission. Comparing spatially resolved single-molecule luminescence spectra from molecules anchored to a step edge with isolated molecules adsorbed on the free surface, we found that the azimuthal modulation of the Lamb shift is diminished in case of the latter. This is evidence that the rapid shuttling motion is remotely induced by plasmon-molecule coupling. Plasmon-induced molecular motion may open an interesting playground to bridge the nanoscopic and mesoscopic worlds by combining molecular machines with nanoplasmonics to control directed motion of single molecules without the need for local probes.
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17
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Jordan JW, Fung KLY, Skowron ST, Allen CS, Biskupek J, Newton GN, Kaiser U, Khlobystov AN. Single-molecule imaging and kinetic analysis of intermolecular polyoxometalate reactions. Chem Sci 2021; 12:7377-7387. [PMID: 34163827 PMCID: PMC8171355 DOI: 10.1039/d1sc01874d] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 04/12/2021] [Indexed: 11/21/2022] Open
Abstract
We induce and study reactions of polyoxometalate (POM) molecules, [PW12O40]3- (Keggin) and [P2W18O62]6- (Wells-Dawson), at the single-molecule level. Several identical carbon nanotubes aligned side by side within a bundle provided a platform for spatiotemporally resolved imaging of ca. 100 molecules encapsulated within the nanotubes by transmission electron microscopy (TEM). Due to the entrapment of POM molecules their proximity to one another is effectively controlled, limiting molecular motion in two dimensions but leaving the third dimension available for intermolecular reactions between pairs of neighbouring molecules. By coupling the information gained from high resolution structural and kinetics experiments via the variation of key imaging parameters in the TEM, we shed light on the reaction mechanism. The dissociation of W-O bonds, a key initial step of POM reactions, is revealed to be reversible by the kinetic analysis, followed by an irreversible bonding of POM molecules to their nearest neighbours, leading to a continuous tungsten oxide nanowire, which subsequently transforms into amorphous tungsten-rich clusters due to progressive loss of oxygen atoms. The overall intermolecular reaction can therefore be described as a step-wise reductive polycondensation of POM molecules, via an intermediate state of an oxide nanowire. Kinetic analysis enabled by controlled variation of the electron flux in TEM revealed the reaction to be highly flux-dependent, which leads to reaction rates too fast to follow under the standard TEM imaging conditions. Although this presents a challenge for traditional structural characterisation of POM molecules, we harness this effect by controlling the conditions around the molecules and tuning the imaging parameters in TEM, which combined with theoretical modelling and image simulation, can shed light on the atomistic mechanisms of the reactions of POMs. This approach, based on the direct space and real time chemical reaction analysis by TEM, adds a new method to the arsenal of single-molecule kinetics techniques.
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Affiliation(s)
- Jack W Jordan
- School of Chemistry, University of Nottingham University Park Nottingham NG7 2RD UK
| | - Kayleigh L Y Fung
- School of Chemistry, University of Nottingham University Park Nottingham NG7 2RD UK
| | - Stephen T Skowron
- School of Chemistry, University of Nottingham University Park Nottingham NG7 2RD UK
| | - Christopher S Allen
- Electron Physical Science Imaging Center, Diamond Light Source Ltd. Didcot OX11 0DE UK
- Department of Materials, University of Oxford Oxford OX1 3HP UK
| | - Johannes Biskupek
- Electron Microscopy Group of Materials Science, Ulm University 89081 Ulm Germany
| | - Graham N Newton
- GSK Carbon Neutral Laboratories for Sustainable Chemistry, University of Nottingham Nottingham NG7 2TU UK
| | - Ute Kaiser
- Electron Microscopy Group of Materials Science, Ulm University 89081 Ulm Germany
| | - Andrei N Khlobystov
- School of Chemistry, University of Nottingham University Park Nottingham NG7 2RD UK
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18
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Martínez‐Tong DE, Pomposo JA, Verde‐Sesto E. Triggering Forces at the Nanoscale: Technologies for Single‐Chain Mechanical Activation and Manipulation. Macromol Rapid Commun 2020; 42:e2000654. [DOI: 10.1002/marc.202000654] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/14/2020] [Indexed: 01/05/2023]
Affiliation(s)
- Daniel E. Martínez‐Tong
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología University of the Basque Country (UPV/EHU) P. Manuel Lardizábal 3 Donostia‐San Sebastián 20018 Spain
- Centro de Física de Materiales (UPV/EHU‐CSIC) P. Manuel Lardizábal 5 San Sebastián 20018 Spain
| | - José A. Pomposo
- Departamento de Polímeros y Materiales Avanzados: Física, Química y Tecnología University of the Basque Country (UPV/EHU) P. Manuel Lardizábal 3 Donostia‐San Sebastián 20018 Spain
- Centro de Física de Materiales (CFM) (CSIC‐UPV/EHU)—Materials Physics Center (MPC) Paseo Manuel de Lardizábal 5 Donostia‐San Sebastián 20018 Spain
- IKERBASQUE—Basque Foundation for Science Plaza Euskadi 5 Bilbao 48009 Spain
| | - Ester Verde‐Sesto
- Centro de Física de Materiales (CFM) (CSIC‐UPV/EHU)—Materials Physics Center (MPC) Paseo Manuel de Lardizábal 5 Donostia‐San Sebastián 20018 Spain
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19
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Sen D, Błoński P, de la Torre B, Jelínek P, Otyepka M. Thermally induced intra-molecular transformation and metalation of free-base porphyrin on Au(111) surface steered by surface confinement and ad-atoms. NANOSCALE ADVANCES 2020; 2:2986-2991. [PMID: 36132418 PMCID: PMC9417104 DOI: 10.1039/d0na00401d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/26/2020] [Indexed: 06/13/2023]
Abstract
We investigated chemical transformations of a fluorinated free-base porphyrin, 5,10,15,20-tetrakis(4-fluorophenyl)-21,23H-porphyrin (2H-4FTPP) under a Au(111) surface confinement and including gold adatoms by using an experiment and density functional theory based first-principles calculations. Annealing of 2H-4FTPP led to cyclodehydrogenation of the molecule to a π-extended fused aromatic planar compound, 2H-4FPP, and metallation of the porphyrin ring by Au atoms to Au-4FPP complex. Noticeable lowering of bond-dissociation energies of the pyrrole's C-H bonds of the Au(111) supported molecule with respect to their values in the gas phase explained the observed on-surface planarization. Our findings also indicate that Au adatoms may catalyze cleavage of C-H/F bonds in temperature-initiated processes on Au surfaces. BDEs and explicit inclusion of Au adatoms helps to rationalize thermally induced chemical reactions on the respective surface.
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Affiliation(s)
- Dipayan Sen
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University Olomouc Czech Republic
| | - Piotr Błoński
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University Olomouc Czech Republic
| | - Bruno de la Torre
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University Olomouc Czech Republic
- Institute of Physics, Academy of Sciences of the Czech Republic Prague Czech Republic
| | - Pavel Jelínek
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University Olomouc Czech Republic
- Institute of Physics, Academy of Sciences of the Czech Republic Prague Czech Republic
| | - Michal Otyepka
- Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University Olomouc Czech Republic
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20
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Doležal J, Merino P, Redondo J, Ondič L, Cahlík A, Švec M. Charge Carrier Injection Electroluminescence with CO-Functionalized Tips on Single Molecular Emitters. NANO LETTERS 2019; 19:8605-8611. [PMID: 31738569 PMCID: PMC7116301 DOI: 10.1021/acs.nanolett.9b03180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We investigate electroluminescence of single molecular emitters on NaCl on Ag(111) and Au(111) with submolecular resolution in a low-temperature scanning probe microscope with tunneling current, atomic force, and light detection capabilities. The role of the tip state is studied in the photon maps of a prototypical emitter, zinc phthalocyanine (ZnPc), using metal and CO-metal tips. CO-functionalization is found to have an impact on the resolution and contrast of the photon maps due to the localized overlap of the p-orbitals on the tip with the molecular orbitals of the emitter. The possibility of using the same CO-functionalized tip for tip-enhanced photon detection and high resolution atomic force is demonstrated. We study the electroluminescence of ZnPc, induced by charge carrier injection at sufficiently high bias voltages. We propose that the distinct level alignment of the ZnPc frontier orbitals with the Au(111) and Ag(111) Fermi levels governs the primary excitation mechanisms as the injection of electrons and holes from the tip into the molecule, respectively. These findings put forward the importance of the tip status in the photon maps and contribute to a better understanding of the photophysics of organic molecules on surfaces.
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Affiliation(s)
- Jiří Doležal
- Institute of Physics, Czech Academy of Sciences, Praha, Czech Republic
| | - Pablo Merino
- Instituto de Ciencia de Materiales de Madrid, CSIC, Sor Juana Inés de la Cruz 3, E28049, Madrid, Spain
- Instituto de Física Fundamental, CSIC, Serrano 121, E28006, Madrid, Spain
| | - Jesus Redondo
- Institute of Physics, Czech Academy of Sciences, Praha, Czech Republic
| | - Lukáš Ondič
- Institute of Physics, Czech Academy of Sciences, Praha, Czech Republic
| | - Aleš Cahlík
- Institute of Physics, Czech Academy of Sciences, Praha, Czech Republic
- Regional Center for Advanced Materials and Technologies, Olomouc, Czech Republic
| | - Martin Švec
- Institute of Physics, Czech Academy of Sciences, Praha, Czech Republic
- Regional Center for Advanced Materials and Technologies, Olomouc, Czech Republic
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