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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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Zinchenko KS, Ardana-Lamas F, Lanfaloni VU, Luu TT, Pertot Y, Huppert M, Wörner HJ. Apparatus for attosecond transient-absorption spectroscopy in the water-window soft-X-ray region. Sci Rep 2023; 13:3059. [PMID: 36810355 PMCID: PMC9944907 DOI: 10.1038/s41598-023-29089-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 01/30/2023] [Indexed: 02/24/2023] Open
Abstract
We present an apparatus for attosecond transient-absorption spectroscopy (ATAS) featuring soft-X-ray (SXR) supercontinua that extend beyond 450 eV. This instrument combines an attosecond table-top high-harmonic light source with mid-infrared (mid-IR) pulses, both driven by 1.7-1.9 mJ, sub-11 fs pulses centered at 1.76 [Formula: see text]m. A remarkably low timing jitter of [Formula: see text] 20 as is achieved through active stabilization of the pump and probe arms of the instrument. A temporal resolution of better than 400 as is demonstrated through ATAS measurements at the argon L[Formula: see text]-edges. A spectral resolving power of 1490 is demonstrated through simultaneous absorption measurements at the sulfur L[Formula: see text]- and carbon K-edges of OCS. Coupled with its high SXR photon flux, this instrument paves the way to attosecond time-resolved spectroscopy of organic molecules in the gas phase or in aqueous solutions, as well as thin films of advanced materials. Such measurements will advance the studies of complex systems to the electronic time scale.
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Affiliation(s)
- Kristina S. Zinchenko
- grid.5801.c0000 0001 2156 2780Laboratory of Physical Chemistry, ETH Zürich, 8093 Zurich, Switzerland
| | - Fernando Ardana-Lamas
- Laboratory of Physical Chemistry, ETH Zürich, 8093, Zurich, Switzerland. .,European XFEL GmbH, 22869, Schenefeld, Germany.
| | - Valentina Utrio Lanfaloni
- grid.5801.c0000 0001 2156 2780Laboratory of Physical Chemistry, ETH Zürich, 8093 Zurich, Switzerland
| | - Tran Trung Luu
- grid.5801.c0000 0001 2156 2780Laboratory of Physical Chemistry, ETH Zürich, 8093 Zurich, Switzerland ,grid.194645.b0000000121742757Department of Physics, The University of Hong Kong, Pokfulam Road, SAR Hong Kong, People’s Republic of China
| | - Yoann Pertot
- grid.5801.c0000 0001 2156 2780Laboratory of Physical Chemistry, ETH Zürich, 8093 Zurich, Switzerland
| | - Martin Huppert
- grid.5801.c0000 0001 2156 2780Laboratory of Physical Chemistry, ETH Zürich, 8093 Zurich, Switzerland ,grid.5991.40000 0001 1090 7501Paul Scherrer Institut, PSI, 5232 Villigen, Switzerland
| | - Hans Jakob Wörner
- grid.5801.c0000 0001 2156 2780Laboratory of Physical Chemistry, ETH Zürich, 8093 Zurich, Switzerland
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Barnard JCT, Lee JP, Alexander O, Jarosch S, Garratt D, Picciuto R, Kowalczyk K, Ferchaud C, Gregory A, Matthews M, Marangos JP. Delivery of stable ultra-thin liquid sheets in vacuum for biochemical spectroscopy. Front Mol Biosci 2022; 9:1044610. [PMID: 36452452 PMCID: PMC9701818 DOI: 10.3389/fmolb.2022.1044610] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 11/01/2022] [Indexed: 08/20/2023] Open
Abstract
The development of ultra-thin flat liquid sheets capable of running in vacuum has provided an exciting new target for X-ray absorption spectroscopy in the liquid and solution phases. Several methods have become available for delivering in-vacuum sheet jets using different nozzle designs. We compare the sheets produced by two different types of nozzle; a commercially available borosillicate glass chip using microfluidic channels to deliver colliding jets, and an in-house fabricated fan spray nozzle which compresses the liquid on an axis out of a slit to achieve collision conditions. We find in our tests that both nozzles are suitable for use in X-ray absorption spectroscopy with the fan spray nozzle producing thicker but more stable jets than the commercial nozzle. We also provide practical details of how to run these nozzles in vacuum.
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Affiliation(s)
- Jonathan C. T. Barnard
- Extreme Light Consortium, Blackett Laboratory, Imperial College London, Department of Physics, London, United Kingdom
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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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Nishimura K, Fu Y, Suda A, Midorikawa K, Takahashi EJ. Apparatus for generation of nanojoule-class water-window high-order harmonics. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:063001. [PMID: 34243496 DOI: 10.1063/5.0045342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/17/2021] [Indexed: 06/13/2023]
Abstract
In our recent study [Fu et al., Commun. Phys. 3(1), 92 (2020)], we have developed an approach for energy-scaling of high-order harmonic generation in the water-window region under a neutral-medium condition. More specifically, we obtained a nanojoule-class water-window soft x-ray harmonic beam under a phase-matching condition. It has been achieved by combining a newly developed terawatt-class mid-infrared femtosecond laser and a loose-focusing geometry for high-order harmonic generation. The generated beam is more than 100 times intense compared to previously reported results. The experimental setup included two key parts: a terawatt mid-infrared femtosecond driving laser [Fu et al., Sci. Rep. 8(1), 7692 (2018)] and a specially designed gas cell. Despite the dramatic drop in the optimal gas pressure for phase-matching due to loose-focusing geometry, it still reached the 1 bar level for helium. Thus, we have designed a double-structured pulsed-gas cell with a differential pumping system, which enabled providing sufficiently high gas pressure. Moreover, it allowed reducing gas consumption significantly. A robust energy-scalable apparatus for high-order harmonic generation developed in this study will enable the generation of over ten-nanojoule water-window attosecond pulses in the near future.
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Affiliation(s)
- Kotaro Nishimura
- Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yuxi Fu
- Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Akira Suda
- Department of Physics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Katsumi Midorikawa
- Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Eiji J Takahashi
- Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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Barreau L, Ross AD, Garg S, Kraus PM, Neumark DM, Leone SR. Efficient table-top dual-wavelength beamline for ultrafast transient absorption spectroscopy in the soft X-ray region. Sci Rep 2020; 10:5773. [PMID: 32238820 PMCID: PMC7113301 DOI: 10.1038/s41598-020-62461-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 03/09/2020] [Indexed: 11/08/2022] Open
Abstract
We present a table-top beamline providing a soft X-ray supercontinuum extending up to 370 eV from high-order harmonic generation with sub-13 fs 1300 nm driving pulses and simultaneous production of sub-5 fs pulses centered at 800 nm. Optimization of high harmonic generation in a long and dense gas medium yields a photon flux of ~ 1.4 × 106 photons/s/1% bandwidth at 300 eV. The temporal resolution of X-ray transient absorption experiments with this beamline is measured to be 11 fs for 800 nm excitation. This dual-wavelength approach, combined with high flux and high spectral and temporal resolution soft X-ray absorption spectroscopy, is a new route to the study of ultrafast electronic dynamics in carbon-containing molecules and materials at the carbon K-edge.
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Affiliation(s)
- Lou Barreau
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Andrew D Ross
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Samay Garg
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
| | - Peter M Kraus
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
- Advanced Research Center for Nanolithography (ARCNL), Science Park 106, 1098 XG, Amsterdam, The Netherlands
| | - Daniel M Neumark
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Stephen R Leone
- Department of Chemistry, University of California, Berkeley, CA, 94720, USA.
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
- Department of Physics, University of California, Berkeley, CA, 94720, USA.
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Naumov AY, Villeneuve DM, Niikura H. High conversion efficiency of an optical parametric amplifier pumped by 1 kHz Ti:Sapphire laser pulses for tunable high-harmonic generation. OPTICS EXPRESS 2020; 28:4088-4098. [PMID: 32122068 DOI: 10.1364/oe.383489] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 01/20/2020] [Indexed: 06/10/2023]
Abstract
We report that high-conversion efficiency of nearly 50% has been realized by combining a commercially available Ti:Sapphire femtosecond, 1 kHz laser system and an optical parametric amplifier (OPA). For an input energy of 2.2 mJ/pulse at 1 kHz and 35 fs duration, the total OPA output energy of the signal plus idler pulses is 1.09 mJ/pulse at a signal wavelength of 1310 nm. We found that the output beam profile is almost flat-top due to high gain saturation in the OPA. Using the signal pulse, we generate high-harmonics in gases and measure the velocity map images of photoelectrons ionized from argon gas as a function of the signal wavelength. We observe that in a particular range of the high-harmonic photon energy, a four-fold photoelectron angular structure is observed in the low kinetic energy region. Our results indicate that the output pulses with the high-conversion efficiency OPA and super Gaussian beam profile can be used for experiments requiring generation of tunable high-harmonics in the extreme ultra-violet region.
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Ruberti M. Onset of ionic coherence and ultrafast charge dynamics in attosecond molecular ionisation. Phys Chem Chem Phys 2019; 21:17584-17604. [PMID: 31372608 DOI: 10.1039/c9cp03074c] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Here is presented a fully ab initio theoretical framework for simulating the correlated many-electron dynamics occurring during and emerging from molecular ionisation by attosecond laser pulses. This is based on the time-dependent (TD) version of the B-spline restricted correlation space (RCS)-algebraic diagrammatic construction (ADC) method, with the full description of the photoelectron and inclusion of electron correlation effects, such as shakeup processes and inter-channel couplings. The nature of the ultrafast charge dynamics in the molecular ion is elucidated by quantitatively predicting the degree of electronic coherence and eigenstate content of the prepared molecular cationic state, beyond the commonly used sudden approximation. The results presented here for the acetylene and ethylene molecules show that even in the high photon energy regime the simulated hole dynamics is quantitatively different from the prediction of the sudden approximation. Moreover, for high-bandwidth ionising pulse, the residual interaction between the cation, in highly-excited shake-up states, and the emitted slow photoelectron gives rise to a loss of coherence in the ionic system which can persist for the first few femtoseconds after ionisation.
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Affiliation(s)
- M Ruberti
- Department of Physics, Imperial College London, Prince Consort Road, London SW7 2AZ, UK.
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9
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The 2018 Nobel Prize in Physics: optical tweezers and chirped pulse amplification. Anal Bioanal Chem 2019; 411:5001-5005. [PMID: 31143967 DOI: 10.1007/s00216-019-01913-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 05/10/2019] [Indexed: 10/26/2022]
Abstract
The 2018 Nobel Prize in Physics was awarded to Arthur Ashkin (prize share ½), Gérard Mourou (prize share ¼), and Donna Strickland (prize share ¼) for "groundbreaking inventions in the field of laser physics." This feature article summarizes the development of "optical tweezers and their application to biological systems" by Arthur Ashkin, as well as the Mourou/Strickland method of "generating high-intensity, ultrashort optical pulses" known as chirped pulse amplification. Further developments are also briefly discussed.
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Ruberti M. Restricted Correlation Space B-Spline ADC Approach to Molecular Ionization: Theory and Applications to Total Photoionization Cross-Sections. J Chem Theory Comput 2019; 15:3635-3653. [PMID: 31136172 DOI: 10.1021/acs.jctc.9b00288] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herein is presented a new approach to the ab initio algebraic diagrammatic construction (ADC) schemes for the polarization propagator, which is explicitly designed to accurately and efficiently describe molecular ionization. The restricted correlation space (RCS) version of the ADC methods up to second order of perturbation theory is derived via the intermediate state representation (ISR) and implemented in the multicenter B-spline basis set for the electronic continuum. Remarkably a general close-coupling structure of the RCS-ADC many-electron wave function, connecting the N-particle to the ( N - 1)-particle ADC intermediate states, emerges naturally as a nontrivial result of the RCS ansatz. Moreover, the introduced RCS-ADC schemes prove to be particularly manageable from a computational point of view, overcoming the practical limitations of the conventional ADC approaches. The quality of the new RCS-ADC( n) approaches is verified by performing a series of total photoionization cross-section calculations on a test set of molecules. The excellent agreement of the results with existing accurate benchmarks demonstrates that the RCS versions of the ADC schemes are optimal and quantitatively accurate methods for studying multichannel molecular photoionization.
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Affiliation(s)
- M Ruberti
- Department of Physics , Imperial College London , Prince Consort Road , London SW7 2AZ , United Kingdom
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Johnson AS, Avni T, Larsen EW, Austin DR, Marangos JP. Attosecond soft X-ray high harmonic generation. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2019; 377:20170468. [PMID: 30929634 PMCID: PMC6452054 DOI: 10.1098/rsta.2017.0468] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
High harmonic generation (HHG) of an intense laser pulse is a highly nonlinear optical phenomenon that provides the only proven source of tabletop attosecond pulses, and it is the key technology in attosecond science. Recent developments in high-intensity infrared lasers have extended HHG beyond its traditional domain of the XUV spectral range (10-150 eV) into the soft X-ray regime (150 eV to 3 keV), allowing the compactness, stability and sub-femtosecond duration of HHG to be combined with the atomic site specificity and electronic/structural sensitivity of X-ray spectroscopy. HHG in the soft X-ray spectral region has significant differences from HHG in the XUV, which necessitate new approaches to generating and characterizing attosecond pulses. Here, we examine the challenges and opportunities of soft X-ray HHG, and we use simulations to examine the optimal generating conditions for the development of high-flux, attosecond-duration pulses in the soft X-ray spectral range. This article is part of the theme issue 'Measurement of ultrafast electronic and structural dynamics with X-rays'.
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Affiliation(s)
- Allan S. Johnson
- ICFO - The Institute of Photonic Sciences, Castelldefels (Barcelona) 08860, Spain
- e-mail:
| | - Timur Avni
- Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, UK
| | - Esben W. Larsen
- Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, UK
| | - Dane R. Austin
- Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, UK
| | - Jon P. Marangos
- Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ, UK
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Affiliation(s)
- Majed Chergui
- Laboratoire de Spectroscopie Ultrarapide (LSU) and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne, ISIC, FSB, Station 6, CH-1015 Lausanne, Switzerland
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