DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Elucidating ultrafast electron dynamics at surfaces using extreme ultraviolet (XUV) reflection–absorption spectroscopy

Journal Article · · ChemComm
DOI: https://doi.org/10.1039/c8cc01745j · OSTI ID:1594152

Here we review the recent development of extreme ultraviolet reflection–absorption (XUV-RA) spectroscopy. This method combines the benefits of X-ray absorption spectroscopy, such as element, oxidation, and spin state specificity, with surface sensitivity and ultrafast time resolution, having a probe depth of only a few nm and an instrument response less than 100 fs. Using this technique we investigated the ultrafast electron dynamics at a hematite (α-Fe2O3) surface. Surface electron trapping and small polaron formation both occur in 660 fs following photoexcitation. These kinetics are independent of surface morphology indicating that electron trapping is not mediated by defects. Instead, small polaron formation is proposed as the likely driving force for surface electron trapping. We also show that in Fe2O3, Co3O4, and NiO, band gap excitation promotes electron transfer from O 2p valence band states to metal 3d conduction band states. In addition to detecting the photoexcited electron at the metal M2,3-edge, the valence band hole is directly observed as transient signal at the O L1-edge. The size of the resulting charge transfer exciton is on the order of a single metal–oxygen bond length. Spectral shifts at the O L1-edge correlate with metal–oxygen bond covalency, confirming the relationship between valence band hybridization and the overpotential for water oxidation. Furthermore, these examples demonstrate the unique ability to measure ultrafast electron dynamics with element and chemical state resolution using XUV-RA spectroscopy. Accordingly, this method is poised to play an important role to reveal chemical details of previously unseen surface electron dynamics.

Research Organization:
The Ohio State Univ., Columbus, OH (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences, and Biosciences Division
Grant/Contract Number:
SC0014051; FA9550-15-1-0204
OSTI ID:
1594152
Alternate ID(s):
OSTI ID: 1434139
Journal Information:
ChemComm, Vol. 54, Issue 34; ISSN 1359-7345
Publisher:
Royal Society of ChemistryCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 21 works
Citation information provided by
Web of Science

References (158)

Benchmarking Hydrogen Evolving Reaction and Oxygen Evolving Reaction Electrocatalysts for Solar Water Splitting Devices journal March 2015
The soft x-ray free-electron laser FLASH at DESY: beamlines, diagnostics and end-stations journal February 2009
Direct Observation of Surface Chemistry Using Ultrafast Soft-X-Ray Pulses journal June 2001
Femtosecond Extreme Ultraviolet Photoemission Spectroscopy: Observation of Ultrafast Charge Transfer at the n-TiO 2 /p-Si(100) Interface with Controlled TiO 2 Oxygen Vacancies journal January 2016
Descriptors of Oxygen-Evolution Activity for Oxides: A Statistical Evaluation journal December 2015
Ultrafast X-ray Pulses from Laser-Produced Plasmas journal February 1991
Probing ultrafast changes of spin and charge density profiles with resonant XUV magnetic reflectivity at the free-electron laser FERMI journal September 2017
Hematite heterostructures for photoelectrochemical water splitting: rational materials design and charge carrier dynamics journal January 2016
Comparative time-resolved photoemission from the Cu(100) and Cu(111) surfaces journal December 2016
The separation of vibrational coherence from ground- and excited-electronic states in P3HT film journal June 2015
Attosecond science journal June 2007
Exciton-exciton annihilation in MoSe 2 monolayers journal March 2014
Spin-orbit coupling in free-radical reactions: on the way to heavy elements journal January 1993
Energy Conversion in Natural and Artificial Photosynthesis journal May 2010
Visible light driven photocatalysis mediated via ligand-to-metal charge transfer (LMCT): an alternative approach to solar activation of titania journal January 2014
Water Oxidation at Hematite Photoelectrodes: The Role of Surface States journal February 2012
X-Ray Absorption Spectra of Water from First Principles Calculations journal May 2006
SwissFEL: The Swiss X-ray Free Electron Laser journal July 2017
Influence of surface structural disorder on linewidths in angle-resolved photoemission spectra journal August 1997
Observation of Rapid Exciton–Exciton Annihilation in Monolayer Molybdenum Disulfide journal September 2014
Femtosecond M 2,3 -Edge Spectroscopy of Transition-Metal Oxides: Photoinduced Oxidation State Change in α-Fe 2 O 3 journal October 2013
Ultra-fast and ultra-intense x-ray sciences: first results from the Linac Coherent Light Source free-electron laser journal August 2013
Time-resolved X-ray absorption spectroscopy for the study of molecular systems relevant for artificial photosynthesis journal December 2015
Non-thermal melting in semiconductors measured at femtosecond resolution journal March 2001
Electronic and nuclear contributions to time-resolved optical and X-ray absorption spectra of hematite and insights into photoelectrochemical performance journal January 2016
Ultrafast Electron Dynamics in Solar Energy Conversion journal May 2017
Ultrafast Plasmon-Enhanced Hot Electron Generation at Ag Nanocluster/Graphite Heterojunctions journal April 2017
Time-resolved two photon photoemission electron microscopy journal March 2002
Ultrafast Studies of Photoexcited Electron Dynamics in γ- and α-Fe 2 O 3 Semiconductor Nanoparticles journal January 1998
High-Resolution X-ray Emission and X-ray Absorption Spectroscopy journal June 2001
Detecting the oxyl radical of photocatalytic water oxidation at an n-SrTiO3/aqueous interface through its subsurface vibration journal April 2016
Phase Transformation and Lithiation Effect on Electronic Structure of Li x FePO 4 : An In-Depth Study by Soft X-ray and Simulations journal August 2012
Direct and simultaneous observation of ultrafast electron and hole dynamics in germanium journal June 2017
Photoreceptor Proteins, “Star Actors of Modern Times”:  A Review of the Functional Dynamics in the Structure of Representative Members of Six Different Photoreceptor Families journal January 2004
Unraveling the Exciton Quenching Mechanism of Quantum Dots on Antimony-Doped SnO 2 Films by Transient Absorption and Single Dot Fluorescence Spectroscopy journal January 2013
Surface Segregation and Backscattering in Doped Silicon Nanowires journal April 2006
Electron Dynamics at the ZnO (101̅0) Surface journal July 2008
Solar Fuels via Artificial Photosynthesis journal December 2009
Separability between valence and conduction bands in transition metal clusters: Valence and Conduction Bands in TM Clusters journal January 2004
The generation, characterization and applications of broadband isolated attosecond pulses journal February 2014
Ultrafast Electron Transfer at the Molecule-Semiconductor Nanoparticle Interface journal May 2005
Carrier dynamics in α‐Fe2O3 (0001) thin films and single crystals probed by femtosecond transient absorption and reflectivity journal March 2006
Surface Segregation Entropy of Protons and Oxygen Vacancies in BaZrO 3 journal February 2016
Auger Recombination in Chemical Vapor Deposition-Grown Monolayer WS 2 journal November 2016
Effect of the surface roughness on the spectral distribution of photoemission current at the silver/solution contact journal May 1995
Dynamics of photogenerated holes in nanocrystalline α-Fe 2 O 3 electrodes for water oxidation probed by transient absorption spectroscopy journal January 2011
Prolonged Hot Electron Dynamics in Plasmonic-Metal/Semiconductor Heterostructures with Implications for Solar Photocatalysis journal June 2014
Ultrafast x-ray pulse generation by focusing femtosecond infrared laser pulses onto aqueous solutions of alkali metal chloride journal May 2002
Ultrafast Charge Carrier Recombination and Trapping in Hematite Photoanodes under Applied Bias journal July 2014
The CTM4XAS program for EELS and XAS spectral shape analysis of transition metal L edges journal October 2010
Revealing the ultrafast charge carrier dynamics in organo metal halide perovskite solar cell materials using time resolved THz spectroscopy journal January 2016
Passivating surface states on water splitting hematite photoanodes with alumina overlayers journal January 2011
Femtosecond x-ray spectroscopy of an electrocyclic ring-opening reaction journal April 2017
Femtosecond Electron-Transfer Dynamics at a Sensitizing Dye−Semiconductor (TiO 2 ) Interface journal January 1996
Two types of luminescence blinking revealed by spectroelectrochemistry of single quantum dots journal November 2011
Observation of a Train of Attosecond Pulses from High Harmonic Generation journal June 2001
Characterization of Photo-Induced Charge Transfer and Hot Carrier Relaxation Pathways in Spinel Cobalt Oxide (Co 3 O 4 ) journal September 2014
Enhancing the carrier thermalization time in organometallic perovskites by halide mixing journal January 2016
Heterogeneous photocatalysis journal January 1993
Ultrafast Studies of Electron Dynamics in Semiconductor and Metal Colloidal Nanoparticles:  Effects of Size and Surface journal October 1997
High-order laser harmonics and synchrotron study of transition metals M 2 , 3 edges journal March 2006
Transition metal complexes as electrocatalysts—Development and applications in electro-oxidation reactions journal September 2007
Femtosecond time-resolved X-ray absorption spectroscopy of liquid using a hard X-ray free electron laser in a dual-beam dispersive detection method journal January 2014
Dynamics of photogenerated holes in surface modified  -Fe2O3 photoanodes for solar water splitting journal July 2012
Visualizing Interfacial Charge Transfer in Ru-Dye-Sensitized TiO 2 Nanoparticles Using X-ray Transient Absorption Spectroscopy journal February 2011
Impact of surface chemistry journal September 2010
Electron trapping and impurity segregation without defects: Ab initio study of perfectly rebonded grain boundaries journal February 1994
Coherent ultrafast charge transfer in an organic photovoltaic blend journal May 2014
DNA Excited-State Dynamics: From Single Bases to the Double Helix journal May 2009
Mapping vibrational surface and bulk modes in a single nanocube journal March 2017
Influence of iron doping on tetravalent nickel content in catalytic oxygen evolving films journal January 2017
Measuring the Surface Photovoltage of a Schottky Barrier under Intense Light Conditions: Zn/p-Si(100) by Laser Time-Resolved Extreme Ultraviolet Photoelectron Spectroscopy journal September 2017
Attosecond band-gap dynamics in silicon journal December 2014
Surface electron dynamics in hematite (α-Fe 2 O 3 ): correlation between ultrafast surface electron trapping and small polaron formation journal January 2017
Unravelling Small-Polaron Transport in Metal Oxide Photoelectrodes journal January 2016
From two-dimensional electron gas to localized charge: Dynamics of polaron formation in organic semiconductors journal January 2015
Light and oxygen induced degradation limits the operational stability of methylammonium lead triiodide perovskite solar cells journal January 2016
Nanostructured Cobalt Oxide Clusters in Mesoporous Silica as Efficient Oxygen-Evolving Catalysts journal February 2009
Diffusion of Nonequilibrium Quasi-Particles in a Cuprate Superconductor journal May 2003
X-ray Transient Absorption and Picosecond IR Spectroscopy of Fulvalene(tetracarbonyl)diruthenium on Photoexcitation journal June 2012
Electrical Properties of NiO journal March 1954
Estimating Hybridization of Transition Metal and Oxygen States in Perovskites from O K -edge X-ray Absorption Spectroscopy journal January 2014
Carrier-Specific Femtosecond XUV Transient Absorption of PbI 2 Reveals Ultrafast Nonradiative Recombination journal December 2017
Picosecond X-ray Absorption Spectroscopy of a Photoinduced Iron(II) Spin Crossover Reaction in Solution journal January 2006
Determination of the Light-Induced Degradation Rate of the Solar Cell Sensitizer N719 on TiO 2 Nanocrystalline Particles journal December 2005
Electrical Properties of α - Fe 2 O 3 journal March 1954
Limiting Perovskite Solar Cell Performance by Heterogeneous Carrier Extraction journal October 2016
High Photoluminescence Quantum Yield in Band Gap Tunable Bromide Containing Mixed Halide Perovskites journal December 2015
Highly Localized Charge Transfer Excitons in Metal Oxide Semiconductors journal January 2018
Coherent Atomic Motions in a Nanostructure Studied by Femtosecond X-ray Diffraction journal December 2004
Ultrafast Elemental and Oxidation-State Mapping of Hematite by 4D Electron Microscopy journal March 2017
Testing variations of the GW approximation on strongly correlated transition metal oxides: hematite (α-Fe2O3) as a benchmark journal January 2011
Efficient hot-electron transfer by a plasmon-induced interfacial charge-transfer transition journal August 2015
Exploring the impact of semicore level electronic relaxation on polaron dynamics: An adiabatic ab initio study of FePO 4 journal January 2016
Exciton–exciton annihilation and relaxation pathways in semiconducting carbon nanotubes journal January 2016
Femtosecond X-ray measurement of coherent lattice vibrations near the Lindemann stability limit journal March 2003
Charge carrier trapping, recombination and transfer in hematite (α-Fe2O3) water splitting photoanodes journal January 2013
Coherence in Energy Transfer and Photosynthesis journal April 2015
Ultrafast Intersystem Crossing in Acetylacetone via Femtosecond X-ray Transient Absorption at the Carbon K-Edge journal November 2017
Excitation-wavelength-dependent small polaron trapping of photoexcited carriers in α-Fe2O3 journal July 2017
Interfacial Charge Transfer Circumventing Momentum Mismatch at Two-Dimensional van der Waals Heterojunctions journal May 2017
Hydrogen Production by Molecular Photocatalysis journal October 2007
Ultrafast dynamics in solids probed by femtosecond time-resolved broadband electronic sum frequency generation journal November 2016
Oxygen 1 s x-ray-absorption edges of transition-metal oxides journal September 1989
Direct Measurement of Off-State Trapping Rate Fluctuations in Single Quantum Dot Fluorescence journal August 2011
Probing electronic binding potentials with attosecond photoelectron wavepackets journal October 2017
Surface electronic states in three-dimensional SnO2 nanostructures journal July 2005
Femtosecond transient reflectivity measurements as a probe for process-induced defects in silicon journal December 1990
Scalable Ligand-Mediated Transport Synthesis of Organic–Inorganic Hybrid Perovskite Nanocrystals with Resolved Electronic Structure and Ultrafast Dynamics journal February 2017
Bandgap Inhomogeneity of a PbSe Quantum Dot Ensemble from Two-Dimensional Spectroscopy and Comparison to Size Inhomogeneity from Electron Microscopy journal January 2017
Ultrafast Structural Rearrangements in the MLCT Excited State for Copper(I) bis- Phenanthrolines in Solution journal February 2007
Electronic and Molecular Structure of Photoexcited [Ru II (bpy) 3 ] 2+ Probed by Picosecond X-ray Absorption Spectroscopy journal April 2006
Photoinduced Structural Dynamics of Molecular Systems Mapped by Time-Resolved X-ray Methods journal May 2017
Quantitative electron spectroscopy of surfaces: A standard data base for electron inelastic mean free paths in solids journal February 1979
Universal energy-level alignment of molecules on metal oxides journal November 2011
Hole localization in Fe 2 O 3 from density functional theory and wave-function-based methods journal August 2017
Surface phonons; past, present and future journal January 1990
Photocatalysis on TiO2 Surfaces: Principles, Mechanisms, and Selected Results journal May 1995
Solar Water Splitting: Progress Using Hematite (α-Fe2O3) Photoelectrodes journal March 2011
Plasmon-induced hot-electron generation at nanoparticle/metal-oxide interfaces for photovoltaic and photocatalytic devices journal January 2014
X-Ray Interactions: Photoabsorption, Scattering, Transmission, and Reflection at E = 50-30,000 eV, Z = 1-92 journal July 1993
Transient optical diffraction of GaN/aqueous interfaces: Interfacial carrier mobility dependence on surface reactivity journal April 2016
Molecular Fluorescence book April 2012
Ultrafast Carrier Dynamics in Hematite Films: The Role of Photoexcited Electrons in the Transient Optical Response journal October 2014
Achieving Surface Sensitivity in Ultrafast XUV Spectroscopy: M 2,3 -Edge Reflection–Absorption of Transition Metal Oxides journal July 2017
Femtosecond Dynamics of Electron Localization at Interfaces journal January 1998
Femtosecond Studies of Electron Dynamics at Interfaces journal February 2000
Rate Law Analysis of Water Oxidation on a Hematite Surface journal May 2015
Plasmonic hot carrier dynamics in solid-state and chemical systems for energy conversion journal January 2016
Molecular photovoltaics journal April 1998
Oxygen vacancies: The origin of n -type conductivity in ZnO journal June 2016
Bulk heterojunction solar cells with internal quantum efficiency approaching 100% journal April 2009
Determination of Molecular Surface Structure, Composition, and Dynamics under Reaction Conditions at High Pressures and at the Solid-Liquid Interface journal May 2011
Determination of spin injection and transport in a ferromagnet/organic semiconductor heterojunction by two-photon photoemission journal November 2008
Ultrafast X-ray Absorption Spectroscopy journal April 2004
Molecular Photovoltaics journal May 2000
53-attosecond X-ray pulses reach the carbon K-edge journal August 2017
Hot-electron-driven charge transfer processes on O 2 / Pt ( 111 ) surface probed by ultrafast extreme-ultraviolet pulses journal December 2002
Probing the Impact of Solvation on Photoexcited Spin Crossover Complexes with High-Precision X-ray Transient Absorption Spectroscopy journal November 2017
Subpicosecond Interfacial Charge Separation in Dye-Sensitized Nanocrystalline Titanium Dioxide Films journal January 1996
Formation of Two-Dimensional Polarons that are Absent in Three-Dimensional Crystals journal June 2007
Thermodynamic efficiency limit of excitonic solar cells journal May 2011
Surface Chemistry of Ruthenium Dioxide in Heterogeneous Catalysis and Electrocatalysis: From Fundamental to Applied Research journal March 2012
Mimicking Photosynthetic Solar Energy Transduction journal January 2001
Charge Carrier Dynamics of Photoexcited Co 3 O 4 in Methanol: Extending High Harmonic Transient Absorption Spectroscopy to Liquid Environments journal September 2014
Quantification of hot carrier thermalization in PbS colloidal quantum dots by power and temperature dependent photoluminescence spectroscopy journal January 2016
Limiting Perovskite Solar Cell Performance by Heterogeneous Carrier Extraction journal October 2016
Achieving Surface Sensitivity in Ultrafast XUV Spectroscopy: M2,3-edge Reflection-Absorption of Transition Metal Oxides conference January 2017
Coherent ultrafast charge transfer in an organic photovoltaic blend conference January 2014
Ultrafast charge carrier recombination and trapping in hematite photoanodes under applied bias text January 2014
Rate law analysis of water oxidation on a hematite surface text January 2015
Prolonged Hot Electron Dynamics in Plasmonic-Metal/Semiconductor Heterostructures with Implications for Solar Photocatalysis journal June 2014
Nanostructured Cobalt Oxide Clusters in Mesoporous Silica as Efficient Oxygen-Evolving Catalysts journal February 2009
Hydrogen Production by Molecular Photocatalysis journal December 2007
Probing ultrafast changes of spin and charge density profiles with resonant XUV magnetic reflectivity at the free-electron laser FERMI text January 2017
Heterogeneous Photocatalysis journal May 2021
X-ray Transient Absorption and Picosecond IR Spectroscopy of Fulvalene(tetracarbonyl)diruthenium on Photoexcitation journal June 2012
Diffusion of Nonequilibrium Quasiparticles in a Cuprate Superconductor text January 2003

Cited By (3)

Controlling polaron formation at hematite surfaces by molecular functionalization probed by XUV reflection-absorption spectroscopy journal September 2019
Transient absorption spectroscopy using high harmonic generation: a review of ultrafast X-ray dynamics in molecules and solids
  • Geneaux, Romain; Marroux, Hugo J. B.; Guggenmos, Alexander
  • Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Vol. 377, Issue 2145 https://doi.org/10.1098/rsta.2017.0463
journal April 2019
Ultrafast Dynamics of Charge Transfer and Photochemical Reactions in Solar Energy Conversion journal October 2018