1
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Leone SR. Reinvented: An Attosecond Chemist. Annu Rev Phys Chem 2024; 75:1-19. [PMID: 38012050 DOI: 10.1146/annurev-physchem-083122-011610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Attosecond science requires a substantial rethinking of how to make measurements on very short timescales; how to acquire the necessary equipment, technology, and personnel; and how to build a set of laboratories for such experiments. This entails a rejuvenation of the author in many respects, in the laboratory itself, with regard to students and postdocs, and in generating funding for research. It also brings up questions of what it means to do attosecond science, and the discovery of the power of X-ray spectroscopy itself, which complements the short timescales addressed. The lessons learned, expressed in the meanderings of this autobiographical article, may be of benefit to others who try to reinvent themselves.
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Affiliation(s)
- Stephen R Leone
- Departments of Chemistry and Physics and Lawrence Berkeley National Laboratory, University of California, Berkeley, California, USA;
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2
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Palmer LD, Lee W, Dong CL, Liu RS, Wu N, Cushing SK. Determining Quasi-Equilibrium Electron and Hole Distributions of Plasmonic Photocatalysts Using Photomodulated X-ray Absorption Spectroscopy. ACS NANO 2024; 18:9344-9353. [PMID: 38498940 PMCID: PMC10993415 DOI: 10.1021/acsnano.3c08181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 03/09/2024] [Accepted: 03/14/2024] [Indexed: 03/20/2024]
Abstract
Most photocatalytic and photovoltaic devices operate under broadband, constant illumination. Electron and hole dynamics in these devices, however, are usually measured by using ultrafast pulsed lasers in a narrow wavelength range. In this work, we use excited-state X-ray theory originally developed for transient X-ray experiments to study steady-state photomodulated X-ray spectra. We use this method to attempt to extract electron and hole distributions from spectra collected at a nontime-resolved synchrotron beamline. A set of plasmonic metal core-shell nanoparticles is designed as the control experiment because they can systematically isolate photothermal, hot electron, and thermalized electron-hole pairs in a TiO2 shell. Steady-state changes in the Ti L2,3 edge are measured with and without continuous-wave illumination of the nanoparticle's localized surface plasmon resonance. The results suggest that within error the quasi-equilibrium carrier distribution can be determined even from relatively noisy data with mixed excited-state phenomena. Just as importantly, the theoretical analysis of noisy data is used to provide guidelines for the beamline development of photomodulated steady-state spectroscopy.
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Affiliation(s)
- Levi Daniel Palmer
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena 91125, California, United States
| | - Wonseok Lee
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena 91125, California, United States
| | - Chung-Li Dong
- Department
of Physics, Tamkang University, New Taipei City 251301, Taiwan
| | - Ru-Shi Liu
- Department
of Chemistry, National Taiwan University
and Advanced Research Center for Green Materials Science and Technology, Taipei 10617, Taiwan
| | - Nianqiang Wu
- Department
of Chemical Engineering, University of Massachusetts
Amherst, Amherst 01003−9303, Massachusetts, United States
| | - Scott Kevin Cushing
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena 91125, California, United States
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3
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Garratt D, Matthews M, Marangos J. Toward ultrafast soft x-ray spectroscopy of organic photovoltaic devices. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2024; 11:010901. [PMID: 38250136 PMCID: PMC10799687 DOI: 10.1063/4.0000214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 12/17/2023] [Indexed: 01/23/2024]
Abstract
Novel ultrafast x-ray sources based on high harmonic generation and at x-ray free electron lasers are opening up new opportunities to resolve complex ultrafast processes in condensed phase systems with exceptional temporal resolution and atomic site specificity. In this perspective, we present techniques for resolving charge localization, transfer, and separation processes in organic semiconductors and organic photovoltaic devices with time-resolved soft x-ray spectroscopy. We review recent results in ultrafast soft x-ray spectroscopy of these systems and discuss routes to overcome the technical challenges in performing time-resolved x-ray experiments on photosensitive materials with poor thermal conductivity and low pump intensity thresholds for nonlinear effects.
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4
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Liu H, Michelsen JM, Mendes JL, Klein IM, Bauers SR, Evans JM, Zakutayev A, Cushing SK. Measuring Photoexcited Electron and Hole Dynamics in ZnTe and Modeling Excited State Core-Valence Effects in Transient Extreme Ultraviolet Reflection Spectroscopy. J Phys Chem Lett 2023; 14:2106-2111. [PMID: 36802601 DOI: 10.1021/acs.jpclett.2c03894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Transient extreme ultraviolet (XUV) spectroscopy is becoming a valuable tool for characterizing solar energy materials because it can separate photoexcited electron and hole dynamics with element specificity. Here, we use surface-sensitive femtosecond XUV reflection spectroscopy to separately measure photoexcited electron, hole, and band gap dynamics of ZnTe, a promising photocathode for CO2 reduction. We develop an ab initio theoretical framework based on density functional theory and the Bethe-Salpeter equation to robustly assign the complex transient XUV spectra to the material's electronic states. Applying this framework, we identify the relaxation pathways and quantify their time scales in photoexcited ZnTe, including subpicosecond hot electron and hole thermalization, surface carrier diffusion, ultrafast band gap renormalization, and evidence of acoustic phonon oscillations.
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Affiliation(s)
- Hanzhe Liu
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jonathan M Michelsen
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Jocelyn L Mendes
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Isabel M Klein
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Sage R Bauers
- Materials Science Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Jake M Evans
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Andriy Zakutayev
- Materials Science Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Scott K Cushing
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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5
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Andrei V, Roh I, Yang P. Nanowire photochemical diodes for artificial photosynthesis. SCIENCE ADVANCES 2023; 9:eade9044. [PMID: 36763656 PMCID: PMC9917021 DOI: 10.1126/sciadv.ade9044] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 01/05/2023] [Indexed: 06/18/2023]
Abstract
Artificial photosynthesis can provide a solution to our current energy needs by converting small molecules such as water or carbon dioxide into useful fuels. This can be accomplished using photochemical diodes, which interface two complementary light absorbers with suitable electrocatalysts. Nanowire semiconductors provide unique advantages in terms of light absorption and catalytic activity, yet great control is required to integrate them for overall fuel production. In this review, we journey across the progress in nanowire photoelectrochemistry (PEC) over the past two decades, revealing design principles to build these nanowire photochemical diodes. To this end, we discuss the latest progress in terms of nanowire photoelectrodes, focusing on the interplay between performance, photovoltage, electronic band structure, and catalysis. Emphasis is placed on the overall system integration and semiconductor-catalyst interface, which applies to inorganic, organic, or biologic catalysts. Last, we highlight further directions that may improve the scope of nanowire PEC systems.
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Affiliation(s)
- Virgil Andrei
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Inwhan Roh
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Liquid Sunlight Alliance, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Peidong Yang
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Liquid Sunlight Alliance, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
- Kavli Energy NanoScience Institute, Berkeley, CA 94720, USA
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6
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Klein IM, Liu H, Nimlos D, Krotz A, Cushing SK. Ab Initio Prediction of Excited-State and Polaron Effects in Transient XUV Measurements of α-Fe 2O 3. J Am Chem Soc 2022; 144:12834-12841. [PMID: 35816667 DOI: 10.1021/jacs.2c03994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Transient X-ray and extreme ultraviolet (XUV) spectroscopies have become invaluable tools for studying photoexcited dynamics due to their sensitivity to carrier occupations and local chemical or structural changes. One of the most studied materials using transient XUV spectroscopy is α-Fe2O3 because of its rich photoexcited dynamics, including small polaron formation. The interpretation of carrier and polaron effects in α-Fe2O3 is currently carried out using a semi-empirical method that is not transferrable to most materials. Here, an ab initio, Bethe-Salpeter equation (BSE) approach is developed that can incorporate photoexcited-state effects into arbitrary material systems. The accuracy of this approach is proven by calculating the XUV absorption spectra for the ground, photoexcited, and polaron states of α-Fe2O3. Furthermore, the theoretical approach allows for the projection of the core-valence excitons and different components of the X-ray transition Hamiltonian onto the band structure, providing new insights into old measurements. From this information, a physical intuition about the origins and nature of the transient XUV spectra can be built. A route to extracting electron and hole energies is even shown possible for highly angular momentum split XUV peaks. This method is easily generalized to K, L, M, and N edges to provide a general approach for analyzing transient X-ray absorption or reflection data.
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Affiliation(s)
- Isabel M Klein
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Hanzhe Liu
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Danika Nimlos
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Alex Krotz
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Scott Kevin Cushing
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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7
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Biswas S, Baker LR. Extreme Ultraviolet Reflection-Absorption Spectroscopy: Probing Dynamics at Surfaces from a Molecular Perspective. Acc Chem Res 2022; 55:893-903. [PMID: 35238529 DOI: 10.1021/acs.accounts.1c00765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Extreme ultraviolet light sources based on high harmonic generation are enabling the development of novel spectroscopic methods to help advance the frontiers of ultrafast science and technology. In this Account, we discuss the development of extreme ultraviolet reflection-absorption (XUV-RA) spectroscopy at near grazing incident reflection geometry and highlight recent applications of this method to study ultrafast electron dynamics at surfaces. Measuring core-to-valence transitions with broadband, femtosecond pulses of XUV light extends the benefits of X-ray absorption spectroscopy to a laboratory tabletop by providing a chemical fingerprint of materials, including the ability to resolve individual elements with sensitivity to oxidation state, spin state, carrier polarity, and coordination geometry. Combining this chemical state sensitivity with femtosecond time resolution provides new insight into the material properties that govern charge carrier dynamics in complex materials. It is well-known that surface dynamics differ significantly from equivalent processes in bulk materials and that charge separation, trapping, transport, and recombination occurring uniquely at surfaces govern the efficiency of numerous technologically relevant processes spanning photocatalysis, photovoltaics, and information storage and processing. Importantly, XUV-RA spectroscopy at near grazing angle is also surface sensitive with a probe depth of ∼3 nm, providing a new window into electronic and structural dynamics at surfaces and interfaces. Here we highlight the unique capabilities and recent applications of XUV-RA spectroscopy to study photoinduced surface dynamics in metal oxide semiconductors, including photocatalytic oxides (Fe2O3, Co3O4 NiO, and CuFeO2) as well as photoswitchable magnetic oxide (CoFe2O4). We first compare the ultrafast electron self-trapping rates via small polaron formation at the surface and bulk of Fe2O3 where we note that the energetics and kinetics of this process differ significantly at the surface. Additionally, we demonstrate the ability to systematically tune this kinetics by molecular functionalization, thereby providing a route to control carrier transport at surfaces. We also measure the spectral signatures of charge transfer excitons with site specific localization of both electrons and holes in a series of transition metal oxide semiconductors (Fe2O3, NiO, Co3O4). The presence of valence band holes probed at the oxygen L1-edge confirms a direct relationship between the metal-oxygen bond covalency and water oxidation efficiency. For a mixed metal oxide CuFeO2 in the layered delafossite structure, XUV-RA reveals that the sub-picosecond hole thermalization from O 2p to Cu 3d states of CuFeO2 leads to the spatial separation of electrons and holes, resulting in exceptional photocatalytic performance for H2 evolution and CO2 reduction of this material. Finally, we provide an example to show the ability of XUV-RA to probe spin state specific dynamics in a photoswitchable ferrimagnet, cobalt ferrite (CoFe2O4). This study provides a detailed understating of ultrafast spin switching in a complex magnetic material with site-specific resolution. In summary, the applications of XUV-RA spectroscopy demonstrated here illustrate the current abilities and future promise of this method to extend molecule-level understanding from well-defined photochemical complexes to complex materials so that charge and spin dynamics at surfaces can be tuned with the precision of molecular photochemistry.
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Affiliation(s)
- Somnath Biswas
- Department of Chemistry, Princeton University, Washington Road, Princeton, New Jersey 08544, United States
| | - L. Robert Baker
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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8
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Shari'ati Y, Vura-Weis J. Ballistic Δ S = 2 intersystem crossing in a cobalt cubane following ligand-field excitation probed by extreme ultraviolet spectroscopy. Phys Chem Chem Phys 2021; 23:26990-26996. [PMID: 34842876 DOI: 10.1039/d1cp04136c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Femtosecond M2,3-edge X-ray absorption near-edge structure (XANES) spectroscopy is used to probe the excited-state dynamics of the cobalt cubane [CoIII4O4](OAc)4(py)4 (OAc = acetate, py = pyridine), a model for water oxidation catalysts. After ligand-field excitation, intersystem crossing (ISC) to a metal-centered quintet occurs in 38 fs. 30% of the hot quintet undergoes ballistic back-ISC directly to the singlet ground state, with the remainder relaxing to a long-lived triplet.
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Affiliation(s)
- Yusef Shari'ati
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
| | - Josh Vura-Weis
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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9
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Rossi TC, Dykstra CP, Haddock TN, Wallick R, Burke JH, Gentle CM, Doumy G, March AM, van der Veen RM. Charge Carrier Screening in Photoexcited Epitaxial Semiconductor Nanorods Revealed by Transient X-ray Absorption Linear Dichroism. NANO LETTERS 2021; 21:9534-9542. [PMID: 34767364 DOI: 10.1021/acs.nanolett.1c02865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Understanding the electronic structure and dynamics of semiconducting nanomaterials at the atomic level is crucial for the realization and optimization of devices in solar energy, catalysis, and optoelectronic applications. We report here on the use of ultrafast X-ray linear dichroism spectroscopy to monitor the carrier dynamics in epitaxial ZnO nanorods after band gap photoexcitation. By rigorously subtracting out thermal contributions and conducting ab initio calculations, we reveal an overall depletion of absorption cross sections in the transient X-ray spectra caused by photogenerated charge carriers screening the core-hole potential of the X-ray absorbing atom. At low laser excitation densities, we observe phase-space filling by excited electrons and holes separately. These results pave the way for carrier- and element-specific probing of charge transfer dynamics across heterostructured interfaces with ultrafast table-top and fourth-generation X-ray sources.
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Affiliation(s)
- Thomas C Rossi
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
| | - Conner P Dykstra
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Tyler N Haddock
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Rachel Wallick
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - John H Burke
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Cecilia M Gentle
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Gilles Doumy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - Anne Marie March
- Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, United States
| | - Renske M van der Veen
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, United States
- Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
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10
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van der Geest MLS, Sadegh N, Meerwijk TM, Wooning EI, Wu L, Bloem R, Castellanos Ortega S, Brouwer AM, Kraus PM. Extreme ultraviolet-excited time-resolved luminescence spectroscopy using an ultrafast table-top high-harmonic generation source. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:113004. [PMID: 34852522 DOI: 10.1063/5.0064780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/28/2021] [Indexed: 06/13/2023]
Abstract
We present a table-top extreme ultraviolet (XUV) beamline for measuring time- and frequency-resolved XUV-excited optical luminescence (XEOL) with additional femtosecond-resolution XUV transient absorption spectroscopy functionality. XUV pulses are generated via high-harmonic generation using a near-infrared pulse in a noble gas medium and focused to excite luminescence from a solid sample. The luminescence is collimated and guided into a streak camera where its spectral components are temporally resolved with picosecond temporal resolution. We time-resolve XUV-excited luminescence and compare the results to luminescence decays excited at longer wavelengths for three different materials: (i) sodium salicylate, an often used XUV scintillator; (ii) fluorescent labeling molecule 4-carbazole benzoic (CB) acid; and (iii) a zirconium metal oxo-cluster labeled with CB, which is a photoresist candidate for extreme-ultraviolet lithography. Our results establish time-resolved XEOL as a new technique to measure transient XUV-driven phenomena in solid-state samples and identify decay mechanisms of molecules following XUV and soft-x-ray excitation.
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Affiliation(s)
- M L S van der Geest
- Advanced Research Center for Nanolithography, Science Park 106, 1098 XG Amsterdam, The Netherlands
| | - N Sadegh
- Advanced Research Center for Nanolithography, Science Park 106, 1098 XG Amsterdam, The Netherlands
| | - T M Meerwijk
- Advanced Research Center for Nanolithography, Science Park 106, 1098 XG Amsterdam, The Netherlands
| | - E I Wooning
- Advanced Research Center for Nanolithography, Science Park 106, 1098 XG Amsterdam, The Netherlands
| | - L Wu
- Advanced Research Center for Nanolithography, Science Park 106, 1098 XG Amsterdam, The Netherlands
| | - R Bloem
- Advanced Research Center for Nanolithography, Science Park 106, 1098 XG Amsterdam, The Netherlands
| | - S Castellanos Ortega
- Advanced Research Center for Nanolithography, Science Park 106, 1098 XG Amsterdam, The Netherlands
| | - A M Brouwer
- Advanced Research Center for Nanolithography, Science Park 106, 1098 XG Amsterdam, The Netherlands
| | - P M Kraus
- Advanced Research Center for Nanolithography, Science Park 106, 1098 XG Amsterdam, The Netherlands
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11
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Shari'ati Y, Vura-Weis J. Polymer thin films as universal substrates for extreme ultraviolet absorption spectroscopy of molecular transition metal complexes. JOURNAL OF SYNCHROTRON RADIATION 2021; 28:1850-1857. [PMID: 34738939 DOI: 10.1107/s1600577521010596] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
Polystyrene and polyvinyl chloride thin films are explored as sample supports for extreme ultraviolet (XUV) spectroscopy of molecular transition metal complexes. Thin polymer films prepared by slip-coating are flat and smooth, and transmit much more XUV light than silicon nitride windows. Analytes can be directly cast onto the polymer surface or co-deposited within it. The M-edge XANES spectra (40-90 eV) of eight archetypal transition metal complexes (M = Mn, Fe, Co, Ni) are presented to demonstrate the versatility of this method. The films are suitable for pump/probe transient absorption spectroscopy, as shown by the excited-state spectra of Fe(bpy)32+ in two different polymer supports.
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Affiliation(s)
- Yusef Shari'ati
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Josh Vura-Weis
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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12
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13
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Cheng W, Guo C, Ke Q, Guo Y. Heavy Metal Ions in Wastewater Affect the Photodegradation of Phenol‐4‐sulfonic Acid over Biphasic TiO
2
/Activated Carbon Fiber Composites. ChemistrySelect 2021. [DOI: 10.1002/slct.202100296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Wu‐Kui Cheng
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Normal University Shanghai 200234 PR China
| | - Cui‐Xiang Guo
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Normal University Shanghai 200234 PR China
| | - Qin‐Fei Ke
- School of Materials Science and Engineering Shanghai Institute of Technology Shanghai 201418 China
| | - Ya‐Ping Guo
- The Education Ministry Key Lab of Resource Chemistry Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Normal University Shanghai 200234 PR China
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14
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Pelli Cresi JS, Principi E, Spurio E, Catone D, O’Keeffe P, Turchini S, Benedetti S, Vikatakavi A, D’Addato S, Mincigrucci R, Foglia L, Kurdi G, Nikolov IP, De Ninno G, Masciovecchio C, Nannarone S, Kopula Kesavan J, Boscherini F, Luches P. Ultrafast Dynamics of Plasmon-Mediated Charge Transfer in Ag@CeO 2 Studied by Free Electron Laser Time-Resolved X-ray Absorption Spectroscopy. NANO LETTERS 2021; 21:1729-1734. [PMID: 33570965 PMCID: PMC8023697 DOI: 10.1021/acs.nanolett.0c04547] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/27/2021] [Indexed: 05/21/2023]
Abstract
Expanding the activity of wide bandgap semiconductors from the UV into the visible range has become a central goal for their application in green solar photocatalysis. The hybrid plasmonic/semiconductor system, based on silver nanoparticles (Ag NPs) embedded in a film of CeO2, is an example of a functional material developed with this aim. In this work, we take advantage of the chemical sensitivity of free electron laser (FEL) time-resolved soft X-ray absorption spectroscopy (TRXAS) to investigate the electron transfer process from the Ag NPs to the CeO2 film generated by the NPs plasmonic resonance photoexcitation. Ultrafast changes (<200 fs) of the Ce N4,5 absorption edge allowed us to conclude that the excited Ag NPs transfer electrons to the Ce atoms of the CeO2 film through a highly efficient electron-based mechanism. These results demonstrate the potential of FEL-based TRXAS measurements for the characterization of energy transfer in novel hybrid plasmonic/semiconductor materials.
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Affiliation(s)
- Jacopo Stefano Pelli Cresi
- Elettra-Sincrotrone
Trieste S.C.p.A., Strada Statale 14 km 163.5 in Area Science Park, 34012 Basovizza, Trieste, Italy
| | - Emiliano Principi
- Elettra-Sincrotrone
Trieste S.C.p.A., Strada Statale 14 km 163.5 in Area Science Park, 34012 Basovizza, Trieste, Italy
| | - Eleonora Spurio
- Dipartimento
FIM, Università degli Studi di Modena
e Reggio Emilia, Via Campi 213/a, 41125 Modena, Italy
- Istituto
Nanoscienze, Consiglio Nazionale delle Ricerche,Via G. Campi 213/a, 41125 Modena, Italy
| | - Daniele Catone
- Division
of Ultrafast Processes in Materials (FLASHit), Istituto di Struttura della Materia (ISM-CNR), Area della Ricerca di Roma 2 Tor Vergata, Via del
Fosso del Cavaliere 100, 00133 Rome, Italy
| | - Patrick O’Keeffe
- Division
of Ultrafast Processes in Materials (FLASHit), Istituto di Struttura della Materia (ISM-CNR), Area della Ricerca di Roma 1, I-00015 Monterotondo, Scalo, Italy
| | - Stefano Turchini
- Division
of Ultrafast Processes in Materials (FLASHit), Istituto di Struttura della Materia (ISM-CNR), Area della Ricerca di Roma 2 Tor Vergata, Via del
Fosso del Cavaliere 100, 00133 Rome, Italy
| | - Stefania Benedetti
- Istituto
Nanoscienze, Consiglio Nazionale delle Ricerche,Via G. Campi 213/a, 41125 Modena, Italy
| | - Avinash Vikatakavi
- Dipartimento
FIM, Università degli Studi di Modena
e Reggio Emilia, Via Campi 213/a, 41125 Modena, Italy
- Istituto
Nanoscienze, Consiglio Nazionale delle Ricerche,Via G. Campi 213/a, 41125 Modena, Italy
| | - Sergio D’Addato
- Dipartimento
FIM, Università degli Studi di Modena
e Reggio Emilia, Via Campi 213/a, 41125 Modena, Italy
- Istituto
Nanoscienze, Consiglio Nazionale delle Ricerche,Via G. Campi 213/a, 41125 Modena, Italy
| | - Riccardo Mincigrucci
- Elettra-Sincrotrone
Trieste S.C.p.A., Strada Statale 14 km 163.5 in Area Science Park, 34012 Basovizza, Trieste, Italy
| | - Laura Foglia
- Elettra-Sincrotrone
Trieste S.C.p.A., Strada Statale 14 km 163.5 in Area Science Park, 34012 Basovizza, Trieste, Italy
| | - Gabor Kurdi
- Elettra-Sincrotrone
Trieste S.C.p.A., Strada Statale 14 km 163.5 in Area Science Park, 34012 Basovizza, Trieste, Italy
| | - Ivaylo P. Nikolov
- Elettra-Sincrotrone
Trieste S.C.p.A., Strada Statale 14 km 163.5 in Area Science Park, 34012 Basovizza, Trieste, Italy
| | - Giovanni De Ninno
- Elettra-Sincrotrone
Trieste S.C.p.A., Strada Statale 14 km 163.5 in Area Science Park, 34012 Basovizza, Trieste, Italy
- Laboratory
of Quantum Optics, University of Nova Gorica, Nova Gorica SI-5000, Slovenia
| | - Claudio Masciovecchio
- Elettra-Sincrotrone
Trieste S.C.p.A., Strada Statale 14 km 163.5 in Area Science Park, 34012 Basovizza, Trieste, Italy
| | - Stefano Nannarone
- IOM,
CNR, s.s. 14, Km. 163.5
in AREA Science Park, 34149 Basovizza, Trieste, Italy
| | - Jagadesh Kopula Kesavan
- Dipartimento di Fisica e Astronomia, Alma
Mater Studiorum − Università di Bologna, Viale C. Berti Pichat 6/2, 40127 Bologna, Italy
| | - Federico Boscherini
- Dipartimento di Fisica e Astronomia, Alma
Mater Studiorum − Università di Bologna, Viale C. Berti Pichat 6/2, 40127 Bologna, Italy
| | - Paola Luches
- Istituto
Nanoscienze, Consiglio Nazionale delle Ricerche,Via G. Campi 213/a, 41125 Modena, Italy
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15
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Cordones AA, Pemmaraju CD, Lee JH, Zegkinoglou I, Ragoussi ME, Himpsel FJ, de la Torre G, Schoenlein RW. Excited-State Charge Distribution of a Donor-π-Acceptor Zn Porphyrin Probed by N K-Edge Transient Absorption Spectroscopy. J Phys Chem Lett 2021; 12:1182-1188. [PMID: 33480697 DOI: 10.1021/acs.jpclett.0c03725] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Zinc porphyrin solar cell dyes with donor-π-acceptor architectures combine light absorber (π), electron-donor, and electron-acceptor moieties inside a single molecule with atomic precision. The donor-π-acceptor design promotes the separation of charge carriers following optical excitation. Here, we probe the excited-state electronic structure within such molecules by combining time-resolved X-ray absorption spectroscopy at the N K-edge with first-principles time-dependent density functional theory (TD-DFT) calculations. Customized Zn porphyrins with strong-donor triphenylamine groups or weak-donor tri-tert-butylbenzene groups were synthesized. Energetically well-separated N K-edge absorption features simultaneously probe the excited-state electronic structure from the perspectives of the macrocycle and triphenylamine N atoms. New absorption transitions between the macrocycle N atoms and the excited-state HOMO vacancy are observed, and the triphenylamine associated absorption feature blue-shifts, consistent with partial oxidation of the donor groups in the excited state.
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Affiliation(s)
- Amy A Cordones
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - C Das Pemmaraju
- SIMES, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Jae Hyuk Lee
- Pohang Accelerator Laboratory, Pohang 37673, Republic of Korea
| | - Ioannis Zegkinoglou
- Faculty of Physics and Astronomy, Ruhr-University Bochum, 44780 Bochum, Germany
| | - Maria-Eleni Ragoussi
- Department of Organic Chemistry, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Franz J Himpsel
- Physics Department, University of Wisconsin Madison, Madison, Wisconsin 53706, United States
| | - Gema de la Torre
- Department of Organic Chemistry, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Robert W Schoenlein
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
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16
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Britz A, Attar AR, Zhang X, Chang HT, Nyby C, Krishnamoorthy A, Park SH, Kwon S, Kim M, Nordlund D, Sainio S, Heinz TF, Leone SR, Lindenberg AM, Nakano A, Ajayan P, Vashishta P, Fritz D, Lin MF, Bergmann U. Carrier-specific dynamics in 2H-MoTe 2 observed by femtosecond soft x-ray absorption spectroscopy using an x-ray free-electron laser. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2021; 8:014501. [PMID: 33511247 PMCID: PMC7808761 DOI: 10.1063/4.0000048] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 12/20/2020] [Indexed: 06/12/2023]
Abstract
Femtosecond carrier dynamics in layered 2H-MoTe2 semiconductor crystals have been investigated using soft x-ray transient absorption spectroscopy at the x-ray free-electron laser (XFEL) of the Pohang Accelerator Laboratory. Following above-bandgap optical excitation of 2H-MoTe2, the photoexcited hole distribution is directly probed via short-lived transitions from the Te 3d 5/2 core level (M5-edge, 572-577 eV) to transiently unoccupied states in the valence band. The optically excited electrons are separately probed via the reduced absorption probability at the Te M5-edge involving partially occupied states of the conduction band. A 400 ± 110 fs delay is observed between this transient electron signal near the conduction band minimum compared to higher-lying states within the conduction band, which we assign to hot electron relaxation. Additionally, the transient absorption signals below and above the Te M5 edge, assigned to photoexcited holes and electrons, respectively, are observed to decay concomitantly on a 1-2 ps timescale, which is interpreted as electron-hole recombination. The present work provides a benchmark for applications of XFELs for soft x-ray absorption studies of carrier-specific dynamics in semiconductors, and future opportunities enabled by this method are discussed.
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Affiliation(s)
| | | | - Xiang Zhang
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
| | - Hung-Tzu Chang
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | | | - Aravind Krishnamoorthy
- Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, California 90089, USA
| | - Sang Han Park
- PAL-XFEL, Pohang Accelerator Laboratory, 80 Jigokro-127-beongil, Nam-gu, Pohang, Gyeongbuk 37673, South Korea
| | - Soonnam Kwon
- PAL-XFEL, Pohang Accelerator Laboratory, 80 Jigokro-127-beongil, Nam-gu, Pohang, Gyeongbuk 37673, South Korea
| | - Minseok Kim
- PAL-XFEL, Pohang Accelerator Laboratory, 80 Jigokro-127-beongil, Nam-gu, Pohang, Gyeongbuk 37673, South Korea
| | - Dennis Nordlund
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Sami Sainio
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | | | | | | | - Aiichiro Nakano
- Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, California 90089, USA
| | - Pulickel Ajayan
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
| | - Priya Vashishta
- Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, California 90089, USA
| | - David Fritz
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Ming-Fu Lin
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Uwe Bergmann
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
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17
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Attar AR, Chang HT, Britz A, Zhang X, Lin MF, Krishnamoorthy A, Linker T, Fritz D, Neumark DM, Kalia RK, Nakano A, Ajayan P, Vashishta P, Bergmann U, Leone SR. Simultaneous Observation of Carrier-Specific Redistribution and Coherent Lattice Dynamics in 2H-MoTe 2 with Femtosecond Core-Level Spectroscopy. ACS NANO 2020; 14:15829-15840. [PMID: 33085888 DOI: 10.1021/acsnano.0c06988] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We employ few-femtosecond extreme ultraviolet (XUV) transient absorption spectroscopy to reveal simultaneously the intra- and interband carrier relaxation and the light-induced structural dynamics in nanoscale thin films of layered 2H-MoTe2 semiconductor. By interrogating the valence electronic structure via localized Te 4d (39-46 eV) and Mo 4p (35-38 eV) core levels, the relaxation of the photoexcited hole distribution is directly observed in real time. We obtain hole thermalization and cooling times of 15 ± 5 fs and 380 ± 90 fs, respectively, and an electron-hole recombination time of 1.5 ± 0.1 ps. Furthermore, excitations of coherent out-of-plane A1g (5.1 THz) and in-plane E1g (3.7 THz) lattice vibrations are visualized through oscillations in the XUV absorption spectra. By comparison to Bethe-Salpeter equation simulations, the spectral changes are mapped to real-space excited-state displacements of the lattice along the dominant A1g coordinate. By directly and simultaneously probing the excited carrier distribution dynamics and accompanying femtosecond lattice displacement in 2H-MoTe2 within a single experiment, our work provides a benchmark for understanding the interplay between electronic and structural dynamics in photoexcited nanomaterials.
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Affiliation(s)
- Andrew R Attar
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Hung-Tzu Chang
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Alexander Britz
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Xiang Zhang
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Ming-Fu Lin
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Aravind Krishnamoorthy
- Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, California 90089, United States
| | - Thomas Linker
- Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, California 90089, United States
| | - David Fritz
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Daniel M Neumark
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Rajiv K Kalia
- Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, California 90089, United States
| | - Aiichiro Nakano
- Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, California 90089, United States
| | - Pulickel Ajayan
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States
| | - Priya Vashishta
- Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, California 90089, United States
| | - Uwe Bergmann
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Stephen R Leone
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Department of Physics, University of California, Berkeley, California 94720, United States
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