1
|
Pan L, Miao P, Horneber A, Meixner AJ, Adam PM, Zhang D. Revealing local structural properties of an atomically thin MoSe 2 surface using optical microscopy. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2022; 13:572-581. [PMID: 35860454 PMCID: PMC9263549 DOI: 10.3762/bjnano.13.49] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 06/02/2022] [Indexed: 06/15/2023]
Abstract
Using a triangular molybdenum diselenide (MoSe2) flake as surface-enhanced Raman spectroscopy (SERS) platform, we demonstrate the dependency of the Raman enhancement on laser beam polarization and local structure using copper phthalocyanine (CuPc) as probe. Second harmonic generation (SHG) and photoluminescence spectroscopy and microscopy are used to reveal the structural irregularities of the MoSe2 flake. The Raman enhancement in the focus of an azimuthally polarized beam, which possesses exclusively an in-plane electric field component is stronger than the enhancement by a focused radially polarized beam, where the out-of-plane electric field component dominates. This phenomenon indicates that the face-on oriented CuPc molecules strongly interact with the MoSe2 flake via charge transfer and dipole-dipole interaction. Furthermore, the Raman scattering maps on the irregular MoSe2 surface show a distinct correlation with the SHG and photoluminescence optical images, indicating the relationship between local structure and optical properties of the MoSe2 flake. These results contribute to understand the impacts of local structural properties on the Raman enhancement at the surface of the 2D transition-metal dichalcogenide.
Collapse
Affiliation(s)
- Lin Pan
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
- Laboratoire Lumière, nanomatériaux et nanotechnologies – L2n, Université de Technologie de Troyes & CNRS EMR 7004, 12 Rue Marie Curie, CS42060, 10004 Troyes Cedex, France
- Center for Light-Matter-Interaction, Sensors and Analytics (LISA+), Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Peng Miao
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
- Center for Light-Matter-Interaction, Sensors and Analytics (LISA+), Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Anke Horneber
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
- Center for Light-Matter-Interaction, Sensors and Analytics (LISA+), Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Alfred J Meixner
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
- Center for Light-Matter-Interaction, Sensors and Analytics (LISA+), Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Pierre-Michel Adam
- Laboratoire Lumière, nanomatériaux et nanotechnologies – L2n, Université de Technologie de Troyes & CNRS EMR 7004, 12 Rue Marie Curie, CS42060, 10004 Troyes Cedex, France
| | - Dai Zhang
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
- Center for Light-Matter-Interaction, Sensors and Analytics (LISA+), Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| |
Collapse
|
2
|
Moriyama T, Umakoshi T, Hattori Y, Taguchi K, Verma P, Kitamura M. Polarization Raman Imaging of Organic Monolayer Islands for Crystal Orientation Analysis. ACS OMEGA 2021; 6:9520-9527. [PMID: 33869932 PMCID: PMC8047675 DOI: 10.1021/acsomega.0c06313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
An organic semiconductor film made of diphenyl derivative dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DPh-DNTT) has high carrier mobility. However, this mobility may be greatly affected by the crystal orientation of the DPh-DNTT's first layer. Polarization Raman microscopy is widely used to quantitatively analyze the molecular orientation, and thus holds great potential as a powerful tool to investigate the crystal orientation of monolayer DPh-DNTT with high spatial resolution. In this study, we demonstrate polarization Raman imaging of monolayer DPh-DNTT islands for crystal orientation analysis. We found that the DPh-DNTT sample indicated a strong dependence of the Raman intensity on the incident polarization direction. Based on the polarization dependence, we developed an analytical method of determining the crystal orientation of the monolayer DPh-DNTT islands and experimentally confirmed that our technique was highly effective at imaging the islands' crystal orientation with a spatial resolution of a few hundred nanometers.
Collapse
Affiliation(s)
- Toki Moriyama
- Department
of Applied Physics, Osaka University, 2-1, Yamadaoka,
Suita, Osaka 565-0871, Japan
| | - Takayuki Umakoshi
- Department
of Applied Physics, Osaka University, 2-1, Yamadaoka,
Suita, Osaka 565-0871, Japan
- PRESTO,
Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Yoshiaki Hattori
- Department
of Electrical and Electronic Engineering, Kobe University, 1-1, Rokkodai-cho, Nada, Kobe 657-8501, Japan
| | - Koki Taguchi
- Department
of Applied Physics, Osaka University, 2-1, Yamadaoka,
Suita, Osaka 565-0871, Japan
| | - Prabhat Verma
- Department
of Applied Physics, Osaka University, 2-1, Yamadaoka,
Suita, Osaka 565-0871, Japan
| | - Masatoshi Kitamura
- Department
of Electrical and Electronic Engineering, Kobe University, 1-1, Rokkodai-cho, Nada, Kobe 657-8501, Japan
| |
Collapse
|
3
|
van den Berg M, Moeinian A, Kobald A, Chen YT, Horneber A, Strehle S, Meixner AJ, Zhang D. Revealing the local crystallinity of single silicon core-shell nanowires using tip-enhanced Raman spectroscopy. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2020; 11:1147-1156. [PMID: 32802717 PMCID: PMC7404174 DOI: 10.3762/bjnano.11.99] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 07/16/2020] [Indexed: 05/26/2023]
Abstract
Tip-enhanced Raman spectroscopy is combined with polarization angle-resolved spectroscopy to investigate the nanometer-scale structural properties of core-shell silicon nanowires (crystalline Si core and amorphous Si shell), which were synthesized by platinum-catalyzed vapor-liquid-solid growth and silicon overcoating by thermal chemical vapor deposition. Local changes in the fraction of crystallinity in these silicon nanowires are characterized at an optical resolution of about 300 nm. Furthermore, we are able to resolve the variations in the intensity ratios of the Raman peaks of crystalline Si and amorphous Si by applying tip-enhanced Raman spectroscopy, at sample positions being 8 nm apart. The local crystallinity revealed using confocal Raman spectroscopy and tip-enhanced Raman spectroscopy agrees well with the high-resolution transmission electron microscopy images. Additionally, the polarizations of Raman scattering and the photoluminescence signal from the tip-sample nanogap are explored by combining polarization angle-resolved emission spectroscopy with tip-enhanced optical spectroscopy. Our work demonstrates the significant potential of resolving local structural properties of Si nanomaterials at the sub-10 nanometer scale using tip-enhanced Raman techniques.
Collapse
Affiliation(s)
- Marius van den Berg
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, Tübingen, Germany
- Center for Light-Matter Interaction, Sensors & Analytics (LISA+), Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, Tübingen, Germany
| | - Ardeshir Moeinian
- Institute of Electronic Devices and Circuits, Ulm University, Albert-Einstein-Allee 45, Ulm, Germany
| | - Arne Kobald
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, Tübingen, Germany
- Center for Light-Matter Interaction, Sensors & Analytics (LISA+), Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, Tübingen, Germany
| | - Yu-Ting Chen
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, Tübingen, Germany
- Center for Light-Matter Interaction, Sensors & Analytics (LISA+), Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, Tübingen, Germany
| | - Anke Horneber
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, Tübingen, Germany
- Center for Light-Matter Interaction, Sensors & Analytics (LISA+), Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, Tübingen, Germany
| | - Steffen Strehle
- Institute of Micro- and Nanotechnology, Technische Universität Ilmenau, Max-Planck-Ring 12, Ilmenau, Germany
| | - Alfred J Meixner
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, Tübingen, Germany
- Center for Light-Matter Interaction, Sensors & Analytics (LISA+), Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, Tübingen, Germany
| | - Dai Zhang
- Institute of Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, Tübingen, Germany
- Center for Light-Matter Interaction, Sensors & Analytics (LISA+), Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, Tübingen, Germany
| |
Collapse
|
4
|
Tang X, van den Berg M, Gu E, Horneber A, Matt GJ, Osvet A, Meixner AJ, Zhang D, Brabec CJ. Local Observation of Phase Segregation in Mixed-Halide Perovskite. NANO LETTERS 2018; 18:2172-2178. [PMID: 29498866 DOI: 10.1021/acs.nanolett.8b00505] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Mixed-halide perovskites have emerged as promising materials for optoelectronics due to their tunable band gap in the entire visible region. A challenge remains, however, in the photoinduced phase segregation, narrowing the band gap of mixed-halide perovskites under illumination thus restricting applications. Here, we use a combination of spatially resolved and bulk measurements to give an in-depth insight into this important yet unclear phenomenon. We demonstrate that photoinduced phase segregation in mixed-halide perovskites selectively occurs at the grain boundaries rather than within the grain centers by using shear-force scanning probe microscopy in combination with confocal optical spectroscopy. Such difference is further evidenced by light-biased bulk Fourier-transform photocurrent spectroscopy, which shows the iodine-rich domain as a minority phase coexisting with the homogeneously mixed phase during illumination. By mapping the surface potential of mixed-halide perovskites, we evidence the higher concentration of positive space charge near the grain boundary possibly provides the initial driving force for phase segregation, while entropic mixing dominates the reverse process. Our work offers detailed insight into the microscopic processes occurring at the boundary of crystalline perovskite grains and will support the development of better passivation strategies, ultimately allowing the processing of more environmentally stable perovskite films.
Collapse
Affiliation(s)
- Xiaofeng Tang
- Institute of Materials for Electronics and Energy Technology (I-MEET), Department of Materials Science and Engineering , Friedrich-Alexander-Universität Erlangen-Nürnberg , Martensstrasse 7 , Erlangen 91058 , Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT) , Paul-Gordan-Strasse 6 , Erlangen 91052 , Germany
| | - Marius van den Berg
- Institute of the Physical and Theoretical Chemistry , University of Tübingen , Auf der Morgenstelle 15 , Tübingen 72074 , Germany
| | - Ening Gu
- Institute of Materials for Electronics and Energy Technology (I-MEET), Department of Materials Science and Engineering , Friedrich-Alexander-Universität Erlangen-Nürnberg , Martensstrasse 7 , Erlangen 91058 , Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT) , Paul-Gordan-Strasse 6 , Erlangen 91052 , Germany
| | - Anke Horneber
- Institute of the Physical and Theoretical Chemistry , University of Tübingen , Auf der Morgenstelle 15 , Tübingen 72074 , Germany
| | - Gebhard J Matt
- Institute of Materials for Electronics and Energy Technology (I-MEET), Department of Materials Science and Engineering , Friedrich-Alexander-Universität Erlangen-Nürnberg , Martensstrasse 7 , Erlangen 91058 , Germany
| | - Andres Osvet
- Institute of Materials for Electronics and Energy Technology (I-MEET), Department of Materials Science and Engineering , Friedrich-Alexander-Universität Erlangen-Nürnberg , Martensstrasse 7 , Erlangen 91058 , Germany
| | - Alfred J Meixner
- Institute of the Physical and Theoretical Chemistry , University of Tübingen , Auf der Morgenstelle 15 , Tübingen 72074 , Germany
| | - Dai Zhang
- Institute of the Physical and Theoretical Chemistry , University of Tübingen , Auf der Morgenstelle 15 , Tübingen 72074 , Germany
| | - Christoph J Brabec
- Institute of Materials for Electronics and Energy Technology (I-MEET), Department of Materials Science and Engineering , Friedrich-Alexander-Universität Erlangen-Nürnberg , Martensstrasse 7 , Erlangen 91058 , Germany
- Bavarian Center for Applied Energy Research (ZAE Bayern) , Haberstrasse 2a , Erlangen 91058 , Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT) , Paul-Gordan-Strasse 6 , Erlangen 91052 , Germany
| |
Collapse
|
5
|
Wang X, Zeng Z, Zhuang X, Wackenhut F, Pan A, Meixner AJ. Second-harmonic generation in single CdSe nanowires by focused cylindrical vector beams. OPTICS LETTERS 2017; 42:2623-2626. [PMID: 28957300 DOI: 10.1364/ol.42.002623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 06/05/2017] [Indexed: 06/07/2023]
Abstract
Cylindrical vector beams with radial or azimuthal polarization have created great interest due to their unique focusing characteristics and focal components. In this Letter, we investigate second-harmonic general (SHG) of single CdSe nanowires (NWs) excited by tightly focused cylindrical vector beams of 150 fs pulses at 800 nm. With the specific polarizations in the focal region, we demonstrate a three-dimensional interaction between the focal electric field components and the NWs. The excitation anisotropy of the SHG can directly be derived from the imaging patterns with the cylindrical vector beams. The highest SHG excitation efficiency is observed when the polarization is parallel to the long axis of the NW, which is confirmed by the conventional linear polarization approach. Our work with cylindrical vector beams provides a new approach to study the nonlinear phenomenon of single semiconductor NWs in three dimensions and it could be applied to many other nanoscale systems.
Collapse
|
6
|
van den Berg M, Back J, Horneber A, Meixner M, Swider K, Ludwigs S, Zhang D. Determination of the Local Morphology within Individual Polymer Domains. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b01671] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marius van den Berg
- Institute
for Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Justus Back
- Institute
of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Anke Horneber
- Institute
for Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Martin Meixner
- Institute
for Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Kathrin Swider
- Institute
for Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| | - Sabine Ludwigs
- Institute
of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Dai Zhang
- Institute
for Physical and Theoretical Chemistry, Eberhard Karls University of Tübingen, Auf der Morgenstelle 15, 72076 Tübingen, Germany
| |
Collapse
|
7
|
Casalegno M, Moret M, Resel R, Raos G. Surface Reconstructions in Organic Crystals: Simulations of the Effect of Temperature and Defectivity on Bulk and (001) Surfaces of 2,2':6',2″-Ternaphthalene. CRYSTAL GROWTH & DESIGN 2016; 16:412-422. [PMID: 26834509 PMCID: PMC4720359 DOI: 10.1021/acs.cgd.5b01405] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 11/17/2015] [Indexed: 06/05/2023]
Abstract
2,2':6',2″-Ternaphthalene (NNN) is a novel, blue-emitting material, suitable for preparation of organic light-emitting diodes. Its crystal structure has been solved recently, but its thermal behavior and surface properties have not yet been explored, partly due to the difficulty in obtaining high quality crystals. In the present study we use classical molecular dynamics to investigate the thermal behavior of bulk and (001) surfaces of NNN. Our bulk simulations indicate the occurrence of a phase transition at about 600 K. The transition is facilitated by the presence of a free (001) surface, since a reconstruction leading to a very similar structure occurs around 550 K in our surface models. This holds for both ideal and defective surface models, containing a small number of vacancies (one or two missing molecules in the outermost layer). In all cases, the process is triggered by thermal motion and involves the reorientation of the molecules with respect to the (001) plane. Both the bulk and surface phases share the monoclinic space group P21/a with a herringbone disposition of molecules. These findings and their implications for the use of NNN in organic electronics are discussed.
Collapse
Affiliation(s)
- Mosè Casalegno
- Dipartimento di Chimica, Materiali e Ingegneria Chimica "G. Natta", Politecnico di Milano , Via L. Mancinelli 7, 20131 Milano, Italy
| | - Massimo Moret
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca , Via R. Cozzi 55, 20125 Milano, Italy
| | - Roland Resel
- Institut für Festkörperphysik, Technische Universität Graz , 60101 Graz, Austria
| | - Guido Raos
- Dipartimento di Chimica, Materiali e Ingegneria Chimica "G. Natta", Politecnico di Milano , Via L. Mancinelli 7, 20131 Milano, Italy
| |
Collapse
|
8
|
Wang X, Broch K, Schreiber F, Meixner AJ, Zhang D. Revealing nanoscale optical properties and morphology in perfluoropentacene films by confocal and tip-enhanced near-field optical microscopy and spectroscopy. Phys Chem Chem Phys 2016; 18:15919-26. [DOI: 10.1039/c6cp01153e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Combining confocal and high resolution near-field optical microscopy and spectroscopy, we propose a sensitive method for determining the local morphology in organic semiconductor thin films.
Collapse
Affiliation(s)
- Xiao Wang
- Institute of Physical and Theoretical Chemistry and LISA+
- University of Tübingen
- 72076 Tübingen
- Germany
| | - Katharina Broch
- Institute of Applied Physics
- University of Tübingen
- 72076 Tübingen
- Germany
- Cavendish Laboratory
| | - Frank Schreiber
- Institute of Applied Physics
- University of Tübingen
- 72076 Tübingen
- Germany
| | - Alfred J. Meixner
- Institute of Physical and Theoretical Chemistry and LISA+
- University of Tübingen
- 72076 Tübingen
- Germany
| | - Dai Zhang
- Institute of Physical and Theoretical Chemistry and LISA+
- University of Tübingen
- 72076 Tübingen
- Germany
| |
Collapse
|