1
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Spellberg JL, Kodaimati L, Joshi PP, Mirzajani N, Liang L, King SB. Electronic structure orientation as a map of in-plane antiferroelectricity in β'-In 2Se 3. SCIENCE ADVANCES 2024; 10:eado2136. [PMID: 38875325 PMCID: PMC11177895 DOI: 10.1126/sciadv.ado2136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 05/10/2024] [Indexed: 06/16/2024]
Abstract
Antiferroelectric (AFE) materials are excellent candidates for sensors, capacitors, and data storage due to their electrical switchability and high-energy storage capacity. However, imaging the nanoscale landscape of AFE domains is notoriously inaccessible, which has hindered development and intentional tuning of AFE materials. Here, we demonstrate that polarization-dependent photoemission electron microscopy can resolve the arrangement and orientation of in-plane AFE domains on the nanoscale, despite the absence of a net lattice polarization. Through direct determination of electronic transition orientations and analysis of domain boundary constraints, we establish that antiferroelectricity in β'-In2Se3 is a robust property from the scale of tens of nanometers to tens of micrometers. Ultimately, the method for imaging AFE domain organization presented here opens the door to investigations of the influence of domain formation and orientation on charge transport and dynamics.
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Affiliation(s)
- Joseph L Spellberg
- Department of Chemistry, University of Chicago, Chicago, IL 60637, USA
- James Franck Institute, University of Chicago, Chicago, IL 60637, USA
| | - Lina Kodaimati
- Department of Chemistry, University of Chicago, Chicago, IL 60637, USA
| | - Prakriti P Joshi
- James Franck Institute, University of Chicago, Chicago, IL 60637, USA
| | - Nasim Mirzajani
- Department of Chemistry, University of Chicago, Chicago, IL 60637, USA
- James Franck Institute, University of Chicago, Chicago, IL 60637, USA
| | - Liangbo Liang
- Center for Nanophase Materials Science, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Sarah B King
- Department of Chemistry, University of Chicago, Chicago, IL 60637, USA
- James Franck Institute, University of Chicago, Chicago, IL 60637, USA
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2
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Winchester AJ, Anderson TJ, Hite JK, Elmquist RE, Pookpanratana S. Methodology and implementation of a tunable deep-ultraviolet laser source for photoemission electron microscopy. Ultramicroscopy 2023; 253:113819. [PMID: 37549583 DOI: 10.1016/j.ultramic.2023.113819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 06/21/2023] [Accepted: 07/25/2023] [Indexed: 08/09/2023]
Abstract
Photoemission electron microscopy (PEEM) is a unique and powerful tool for studying the electronic properties of materials and surfaces. However, it requires intense and well-controlled light sources with photon energies ranging from the UV to soft X-rays for achieving high spatial resolution and image contrast. Traditionally, many PEEMs were installed at synchrotron light sources to access intense and tunable soft X-rays. More recently, the maturation of solid-state lasers has opened a new avenue for laboratory-based PEEMs using laser-based UV light at lower photon energies. Here, we report on the characteristics of a laser-based UV light source that was recently integrated with a PEEM instrument. The system consists of a high repetition rate, tunable wavelength laser coupled to a harmonics generation module, which generates deep-UV radiation from 192 nm to 210 nm. We comment on the spectral characteristics and overall laser system stability, as well as on the effects of space charge within the PEEM microscope at high UV laser fluxes. Further, we show an example of imaging on gallium nitride, where the higher UV photon energy and flux of the laser provides considerably improved image quality, compared to a conventional light source. These results demonstrate the capabilities of laser-based UV light sources for advancing laboratory-based PEEMs.
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Affiliation(s)
- Andrew J Winchester
- Nanoscale Device and Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD, United States
| | - Travis J Anderson
- Electronics Science and Technology Division, U.S. Naval Research Laboratory, Washington, DC, United States
| | - Jennifer K Hite
- Electronics Science and Technology Division, U.S. Naval Research Laboratory, Washington, DC, United States
| | - Randolph E Elmquist
- Quantum Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, United States
| | - Sujitra Pookpanratana
- Nanoscale Device and Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD, United States.
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3
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Beechem TE, Smith SW, Copeland RG, Liu F, Ohta T. Spectral and polarization based imaging in deep-ultraviolet excited photoelectron microscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:053701. [PMID: 35649785 DOI: 10.1063/5.0077867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Using photoelectron emission microscopy, nanoscale spectral imaging of atomically thin MoS2 buried between Al2O3 and SiO2 is achieved by monitoring the wavelength and polarization dependence of the photoelectron signal excited by deep-ultraviolet light. Although photons induce the photoemission, images can exhibit resolutions below the photon wavelength as electrons sense the response. To validate this concept, the dependence of photoemission yield on the wavelength and polarization of the exciting light was first measured and then compared to simulations of the optical response quantified with classical optical theory. A close correlation between experiment and theory indicates that photoemission probes the optical interaction of UV-light with the material stack directly. The utility of this probe is then demonstrated when both the spectral and polarization dependence of photoemission observe spatial variation consistent with grains and defects in buried MoS2. Taken together, these new modalities of photoelectron microscopy allow mapping of optical property variation at length scales unobtainable with conventional light-based microscopy.
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Affiliation(s)
- Thomas E Beechem
- School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA
| | - Sean W Smith
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - R Guild Copeland
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - Fangze Liu
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Taisuke Ohta
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
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4
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Joshi P, Li R, Spellberg JL, Liang L, King SB. Nanoimaging of the Edge-Dependent Optical Polarization Anisotropy of Black Phosphorus. NANO LETTERS 2022; 22:3180-3186. [PMID: 35380445 PMCID: PMC9052752 DOI: 10.1021/acs.nanolett.1c03849] [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: 10/05/2021] [Revised: 03/29/2022] [Indexed: 06/14/2023]
Abstract
The electronic structure and functionality of 2D materials is highly sensitive to structural morphology, not only opening the possibility for manipulating material properties but also making predictable and reproducible functionality challenging. Black phosphorus (BP), a corrugated orthorhombic 2D material, has in-plane optical absorption anisotropy critical for applications, such as directional photonics, plasmonics, and waveguides. Here, we use polarization-dependent photoemission electron microscopy to visualize the anisotropic optical absorption of BP with 54 nm spatial resolution. We find the edges of BP flakes have a shift in their optical polarization anisotropy from the flake interior due to the 1D confinement and symmetry reduction at flake edges that alter the electronic charge distributions and transition dipole moments of edge electronic states, confirmed with first-principles calculations. These results uncover previously hidden modification of the polarization-dependent absorbance at the edges of BP, highlighting the opportunity for selective excitation of edge states of 2D materials with polarized light.
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Affiliation(s)
- Prakriti
P. Joshi
- James
Franck Institute, University of Chicago, Chicago, Illinois 60637 United States
| | - Ruiyu Li
- James
Franck Institute, University of Chicago, Chicago, Illinois 60637 United States
- Department
of Chemistry, University of Chicago, Chicago, Illinois 60637 United States
| | - Joseph L. Spellberg
- James
Franck Institute, University of Chicago, Chicago, Illinois 60637 United States
- Department
of Chemistry, University of Chicago, Chicago, Illinois 60637 United States
| | - Liangbo Liang
- Center
for Nanophase Materials Sciences, Oak Ridge
National Laboratory, Oak Ridge, Tennessee 37830 United States
| | - Sarah B. King
- James
Franck Institute, University of Chicago, Chicago, Illinois 60637 United States
- Department
of Chemistry, University of Chicago, Chicago, Illinois 60637 United States
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5
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Ullmann S, Börner M, Kahnt A, Abel B, Kersting B. Green‐Emissive Zn
2+
Complex Supported by a Macrocyclic Schiff‐Base/Calix[4]arene‐Ligand: Crystallographic and Spectroscopic Characterization. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Steve Ullmann
- Institut für Anorganische Chemie Universität Leipzig Johannisallee 29 04103 Leipzig Germany
- Institut für Nichtklassische Chemie e.V. Permoserstraße. 15 04318 Leipzig
| | - Martin Börner
- Institut für Anorganische Chemie Universität Leipzig Johannisallee 29 04103 Leipzig Germany
- Leibniz Institute of Surface Engineering (IOM) Department of Functional Surfaces Permoserstr. 15 04318 Leipzig Germany
| | - Axel Kahnt
- Leibniz Institute of Surface Engineering (IOM) Department of Functional Surfaces Permoserstr. 15 04318 Leipzig Germany
| | - Bernd Abel
- Leibniz Institute of Surface Engineering (IOM) Department of Functional Surfaces Permoserstr. 15 04318 Leipzig Germany
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie Universität Leipzig Linnéstraße 2 04103 Leipzig Germany
| | - Berthold Kersting
- Institut für Anorganische Chemie Universität Leipzig Johannisallee 29 04103 Leipzig Germany
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6
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Xu J, Liu Z, Jing L, Chen J. Fabrication of PCDTBT Conductive Network via Phase Separation. MATERIALS (BASEL, SWITZERLAND) 2021; 14:5071. [PMID: 34501162 PMCID: PMC8433801 DOI: 10.3390/ma14175071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 11/17/2022]
Abstract
Poly[N-9'-hepta-decanyl-2,7-carbazole-alt-5-5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT) is a stable semiconducting polymer with high rigidity in its molecular chains, which makes it difficult to organize into an ordered structure and affects the device performance. Here, a PCDTBT network consisting of aggregates and nanofibers in thin films was fabricated through the phase separation of mixed PCDTBT and polyethylene glycol (PEG). Using atomic force microscopy (AFM), the effect of the blending conditions (weight ratio, solution concentration, and molecular weight) and processing conditions (substrate temperature and solvent) on the resulting phase-separated morphologies of the blend films after a selective washing procedure was studied. It was found that the phase-separated structure's transition from an island to a continuous structure occurred when the weight ratio of PCDTBT/PEG changed from 2:8 to 7:3. Increasing the solution concentration from 0.1 to 3.0 wt% led to an increase in both the height of the PCDTBT aggregate and the width of the nanofiber. When the molecular weight of the PEG was increased, the film exhibited a larger PCDTBT aggregate size. Meanwhile, denser nanofibers were found in films prepared using PCDTBT with higher molecular weight. Furthermore, the electrical characteristics of the PCDTBT network were measured using conductive AFM. Our findings suggest that phase separation plays an important role in improving the molecular chain diffusion rate and fabricating the PCDTBT network.
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Affiliation(s)
- Jianwei Xu
- School of Materials Science & Engineering, Zhengzhou University, Zhengzhou 450002, China; (Z.L.); (L.J.)
| | | | | | - Jingbo Chen
- School of Materials Science & Engineering, Zhengzhou University, Zhengzhou 450002, China; (Z.L.); (L.J.)
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7
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Sharma PA, Ohta T, Brumbach MT, Sugar JD, Michael J. Ex Situ Photoelectron Emission Microscopy of Polycrystalline Bismuth and Antimony Telluride Surfaces Exposed to Ambient Oxidation. ACS APPLIED MATERIALS & INTERFACES 2021; 13:18218-18226. [PMID: 33835776 DOI: 10.1021/acsami.0c22725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The surfaces of textured polycrystalline N-type bismuth telluride and P-type antimony telluride materials were investigated using ex situ photoelectron emission microscopy (PEEM). PEEM enabled imaging of the work function for different oxidation times due to exposure to air across sample surfaces. The spatially averaged work function was also tracked as a function of air exposure time. N-type bismuth telluride showed an increase in the work function around grain boundaries relative to grain interiors during the early stages of air exposure-driven oxidation. At longer time exposure to air, the surface became homogenous after a ∼5 nm-thick oxide formed. X-ray photoemission spectroscopy was used to correlate changes in PEEM imaging in real space and work function evolution to the progressive growth of an oxide layer. The observed work function contrast is consistent with the pinning of electronic surface states due to the defects at a grain boundary.
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Affiliation(s)
- Peter A Sharma
- Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
| | - Taisuke Ohta
- Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
| | - Michael T Brumbach
- Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
| | - Joshua D Sugar
- Sandia National Laboratories, Livermore, California 94550, United States
| | - Joseph Michael
- Sandia National Laboratories, Albuquerque, New Mexico 87185, United States
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8
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Skallberg A, Bunnfors K, Brommesson C, Uvdal K. New Tools for Imaging Neutrophils: Work Function Mapping and Element-Specific, Label-Free Imaging of Cellular Structures. NANO LETTERS 2021; 21:222-229. [PMID: 33263404 PMCID: PMC7809688 DOI: 10.1021/acs.nanolett.0c03554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 11/17/2020] [Indexed: 06/12/2023]
Abstract
Photoemission electron microscopy and imaging X-ray photoelectron spectroscopy are today frequently used to obtain chemical and electronic states, chemical shifts, work function profiles within the fields of surface- and material sciences. Lately, because of recent technological advances, these tools have also been valuable within life sciences. In this study, we have investigated the power of photoemission electron microscopy and imaging X-ray photoelectron spectroscopy for visualization of human neutrophil granulocytes. These cells, commonly called neutrophils, are essential for our innate immune system. We hereby investigate the structure and morphology of neutrophils when adhered to gold and silicon surfaces. Energy-filtered imaging of single cells are acquired. The characteristic polymorphonuclear cellular nuclei divided into 2-5 lobes is visualized. Element-specific imaging is achieved based on O 1s, P 2p, C 1s, Si 2p, and N 1s core level spectra, delivering elemental distribution with submicrometer resolution, illustrating the strength of this type of cellular morphological studies.
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Affiliation(s)
- Andreas Skallberg
- Department
of Physics, Chemistry and Biology (IFM), Division of Molecular Surface
Physics and Nano Science, Linköping
University, Linköping SE-581 83, Sweden
| | - Kalle Bunnfors
- Department
of Physics, Chemistry and Biology (IFM), Division of Molecular Surface
Physics and Nano Science, Linköping
University, Linköping SE-581 83, Sweden
| | - Caroline Brommesson
- Department
of Physics, Chemistry and Biology (IFM), Division of Molecular Surface
Physics and Nano Science, Linköping
University, Linköping SE-581 83, Sweden
| | - Kajsa Uvdal
- Department
of Physics, Chemistry and Biology (IFM), Division of Molecular Surface
Physics and Nano Science, Linköping
University, Linköping SE-581 83, Sweden
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9
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Da Browski M, Dai Y, Petek H. Ultrafast Photoemission Electron Microscopy: Imaging Plasmons in Space and Time. Chem Rev 2020; 120:6247-6287. [PMID: 32530607 DOI: 10.1021/acs.chemrev.0c00146] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Plasmonics is a rapidly growing field spanning research and applications across chemistry, physics, optics, energy harvesting, and medicine. Ultrafast photoemission electron microscopy (PEEM) has demonstrated unprecedented power in the characterization of surface plasmons and other electronic excitations, as it uniquely combines the requisite spatial and temporal resolution, making it ideally suited for 3D space and time coherent imaging of the dynamical plasmonic phenomena on the nanofemto scale. The ability to visualize plasmonic fields evolving at the local speed of light on subwavelength scale with optical phase resolution illuminates old phenomena and opens new directions for growth of plasmonics research. In this review, we guide the reader thorough experimental description of PEEM as a characterization tool for both surface plasmon polaritons and localized plasmons and summarize the exciting progress it has opened by the ultrafast imaging of plasmonic phenomena on the nanofemto scale.
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Affiliation(s)
- Maciej Da Browski
- Department of Physics and Astronomy and Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States.,Department of Physics and Astronomy, University of Exeter, Stocker Road, Exeter, Devon EX4 4QL, U.K
| | - Yanan Dai
- Department of Physics and Astronomy and Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Hrvoje Petek
- Department of Physics and Astronomy and Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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10
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Niefind F, Karande S, Frost F, Abel B, Kahnt A. Solvent influence on the surface morphology of P3HT thin films revealed by photoemission electron microscopy. NANOSCALE ADVANCES 2019; 1:3883-3886. [PMID: 36132106 PMCID: PMC9417572 DOI: 10.1039/c9na00419j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 08/30/2019] [Indexed: 06/15/2023]
Abstract
Only rigorous understanding of the relationship between the nanoscale morphology of organic thin films and the performance of the devices built from them will ultimately lead to design rules that can guide a structured development on the field of organic electronics. Despite great effort, unraveling the nanoscale structure of the films is still a challenge in itself. Here we demonstrate that photoemission electron microscopy can provide valuable insights into the chain orientation, domains size and grain boundary characteristics of P3HT films spun cast from different solvents at room as well as at elevated temperatures.
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Affiliation(s)
- Falk Niefind
- Leibniz Institute of Surface Engineering (IOM) Permoserstr. 15 04318 Leipzig Germany
| | - Shubhangi Karande
- Leibniz Institute of Surface Engineering (IOM) Permoserstr. 15 04318 Leipzig Germany
| | - Frank Frost
- Leibniz Institute of Surface Engineering (IOM) Permoserstr. 15 04318 Leipzig Germany
| | - Bernd Abel
- Leibniz Institute of Surface Engineering (IOM) Permoserstr. 15 04318 Leipzig Germany
| | - Axel Kahnt
- Leibniz Institute of Surface Engineering (IOM) Permoserstr. 15 04318 Leipzig Germany
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11
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Niefind F, Neff A, Mannsfeld SCB, Kahnt A, Abel B. Computational analysis of the orientation persistence length of the polymer chain orientation. Phys Chem Chem Phys 2019; 21:21464-21472. [PMID: 31535122 DOI: 10.1039/c9cp02944c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Analyzing and interpreting the nanoscale morphology of semiconducting polymers is one of the key challenges for advancing in organic electronics. The orientation persistence length (OPL) as a tool to analyze orientation maps generated by photoemission electron microscopy (PEEM) - a state of the art tool for nanoscale imaging/spectroscopy - is presented here. The OPL is a way to quantify the chain orientation within the polymer film in a single graph. In this regard, it is a convincing method that will enable additional direct correlations between the chain orientation and electrical or optical parameters. In this report, we provide computational insights into the factors that contribute to the OPL.
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Affiliation(s)
- Falk Niefind
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, 04318 Leipzig, Germany.
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12
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Noriega R. Efficient Charge Transport in Disordered Conjugated Polymer Microstructures. Macromol Rapid Commun 2018; 39:e1800096. [DOI: 10.1002/marc.201800096] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 03/12/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Rodrigo Noriega
- Chemistry Department; University of Utah; 315 S 1400 E Salt Lake City UT 84112 USA
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13
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Yang J, Park H, Kaufman LJ. In Situ Optical Imaging of the Growth of Conjugated Polymer Aggregates. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201710336] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Jaesung Yang
- Department of Chemistry Columbia University 3000 Broadway New York NY 10027 USA
| | - Heungman Park
- Department of Chemistry Columbia University 3000 Broadway New York NY 10027 USA
- Department of Physics and Astronomy Texas A&M University—Commerce Commerce TX 75429 USA
| | - Laura J. Kaufman
- Department of Chemistry Columbia University 3000 Broadway New York NY 10027 USA
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14
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Yang J, Park H, Kaufman LJ. In Situ Optical Imaging of the Growth of Conjugated Polymer Aggregates. Angew Chem Int Ed Engl 2018; 57:1826-1830. [DOI: 10.1002/anie.201710336] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 12/02/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Jaesung Yang
- Department of Chemistry Columbia University 3000 Broadway New York NY 10027 USA
| | - Heungman Park
- Department of Chemistry Columbia University 3000 Broadway New York NY 10027 USA
- Department of Physics and Astronomy Texas A&M University—Commerce Commerce TX 75429 USA
| | - Laura J. Kaufman
- Department of Chemistry Columbia University 3000 Broadway New York NY 10027 USA
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