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183 results on '"Naumenko, Denys"'

1. Ultrafast opto-magnetic effects in the extreme ultraviolet spectral range

Author

Hennecke, Martin, von Korff Schmising, Clemens, Yao, Kelvin, Jal, Emmanuelle, Vodungbo, Boris, Chardonnet, Valentin, Légaré, Katherine, Capotondi, Flavio, Naumenko, Denys, Pedersoli, Emanuele, Lopez-Quintas, Ignacio, Nikolov, Ivaylo P., Raimondi, Lorenzo, De Ninno, Giovanni, Salemi, Leandro, Ruta, Sergiu, Chantrell, Roy, Ostler, Thomas, Pfau, Bastian, Engel, Dieter, Oppeneer, Peter M., Eisebitt, Stefan, and Radu, Ilie

Published
2024
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2. Ultrafast Opto-magnetic Effects in the Extreme Ultraviolet Spectral Range

Author

Hennecke, Martin, Schmising, Clemens von Korff, Yao, Kelvin, Jal, Emmanuelle, Vodungbo, Boris, Chardonnet, Valentin, Légaré, Katherine, Capotondi, Flavio, Naumenko, Denys, Pedersoli, Emanuele, Lopez-Quintas, Ignacio, Nikolov, Ivaylo P., Raimondi, Lorenzo, De Ninno, Giovanni, Salemi, Leandro, Ruta, Sergiu, Chantrell, Roy, Ostler, Thomas, Pfau, Bastian, Engel, Dieter, Oppeneer, Peter M., Eisebitt, Stefan, and Radu, Ilie

Subjects
Condensed Matter - Materials Science
Abstract

Coherent light-matter interactions mediated by opto-magnetic phenomena like the inverse Faraday effect (IFE) are expected to provide a non-thermal pathway for ultrafast manipulation of magnetism on timescales as short as the excitation pulse itself. As the IFE scales with the spin-orbit coupling strength of the involved electronic states, photo-exciting the strongly spin-orbit coupled core-level electrons in magnetic materials appears as an appealing method to transiently generate large opto-magnetic moments. Here, we investigate this scenario in a ferrimagnetic GdFeCo alloy by using intense and circularly polarized pulses of extreme ultraviolet radiation. Our results reveal ultrafast and strong helicity-dependent magnetic effects which are in line with the characteristic fingerprints of an IFE, corroborated by ab initio opto-magnetic IFE theory and atomistic spin dynamics simulations.

Published
2023
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3. Implication of the double-gating mode in hybrid photon counting detector for measurements of transient heat conduction in GaAs/AlAs superlattice structures

Author

Naumenko, Denys, Burian, Max, Marmiroli, Benedetta, Haider, Richard, Radeticchio, Andrea, Wagner, Lucas, Piazza, Luca, Glatt, Lisa, Brandstetter, Stefan, Zilio, Simone Dal, Biasiol, Giorgio, and Amenitsch, Heinz

Subjects
Physics - Applied Physics, Condensed Matter - Materials Science
Abstract

Understanding and control of thermal transport in solids at nanoscale is crucial to engineer and to enhance properties of a new generation of optoelectronic, thermoelectric, and photonic devices. In this regard, semiconductor superlattice structures provide a unique platform to study phenomena associated with phonon propagations in solids such as heat conduction. Transient X-ray diffraction can directly probe atomic motions and therefore is among the rare techniques sensitive to phonon dynamics in a condensed matter. Here, we study optically induced transient heat conduction in GaAs/AlAs superlattice structures using EIGER2 detector. Benchmark experiments have been performed at the Austrian SAXS beamline at Elettra Sincrotrone Trieste that operated in the hybrid filling mode. We demonstrate that drifts of experimental conditions, such as synchrotron beam fluctuations, become less essential when utilizing EIGER2 double gating mode that results in a faster acquisition of high quality data and facilitates data analysis and data interpretation., Comment: 15 pages, 9 figures, 1 table

Published
2023

4. Atom-Specific Probing of Electron Dynamics in an Atomic Adsorbate by Time-Resolved X-ray Spectroscopy

Author

Schreck, Simon, Diesen, Elias, Dell'Angela, Martina, Liu, Chang, Weston, Matthew, Capotondi, Flavio, Ogasawara, Hirohito, LaRue, Jerry, Costantini, Roberto, Beye, Martin, Miedema, Piter S., Stenlid, Joakim Halldin, Gladh, Jörgen, Liu, Boyang, Wang, Hsin-Yi, Perakis, Fivos, Cavalca, Filippo, Koroidov, Sergey, Amann, Peter, Pedersoli, Emanuele, Naumenko, Denys, Nikolov, Ivaylo, Raimondi, Lorenzo, Abild-Pedersen, Frank, Heinz, Tony F., Voss, Johannes, Luntz, Alan C., and Nilsson, Anders

Subjects
Physics - Chemical Physics, Condensed Matter - Materials Science
Abstract

The electronic excitation occurring on adsorbates at ultrafast time scales from optical lasers that initiate surface chemical reactions is still an open question. Here, we report the ultrafast temporal evolution of X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) of a simple well known adsorbate prototype system, namely carbon (C) atoms adsorbed on a nickel (Ni(100)) surface, following intense laser optical pumping at 400 nm. We observe ultrafast (~100 fs) changes in both XAS and XES showing clear signatures of the formation of a hot electron-hole pair distribution on the adsorbate. This is followed by slower changes on a few ps time scale, shown to be consistent with thermalization of the complete C/Ni system. Density functional theory spectrum simulations support this interpretation., Comment: 33 pages, 12 figures. Submitted to Physical Review Letters

Published
2022
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5. Ultrafast adsorbate excitation probed with sub-ps resolution XAS

Author

Diesen, Elias, Wang, Hsin-Yi, Schreck, Simon, Weston, Matthew, Ogasawara, Hirohito, LaRue, Jerry, Perakis, Fivos, Dell'Angela, Martina, Capotondi, Flavio, Giannessi, Luca, Pedersoli, Emanuele, Naumenko, Denys, Nikolov, Ivaylo, Raimondi, Lorenzo, Spezzani, Carlo, Beye, Martin, Cavalca, Filippo, Liu, Boyang, Gladh, Jörgen, Koroidov, Sergey, Miedema, Piter S., Costantini, Roberto, Heinz, Tony F., Abild-Pedersen, Frank, Voss, Johannes, Luntz, Alan C., and Nilsson, Anders

Subjects
Physics - Chemical Physics
Abstract

We use a pump-probe scheme to measure the time evolution of the C K-edge X-ray absorption spectrum (XAS) from CO/Ru(0001) after excitation by an ultrashort high-intensity optical laser pulse. Due to the short duration of the X-ray probe pulse and precise control of the pulse delay, the excitation-induced dynamics during the first ps after the pump can be resolved with unprecedented time resolution. By comparing with theoretical (DFT) spectrum calculations we find high excitation of the internal stretch and frustrated rotation modes occurring within 200 fs of laser excitation, as well as thermalization of the system in the ps regime. The ~100 fs initial excitation of these CO vibrational modes is not readily rationalized by traditional theories of nonadiabatic coupling of adsorbates to metal surfaces, e. g. electronic frictions based on first order electron-phonon coupling or transient population of adsorbate resonances. We suggest that coupling of the adsorbate to non-thermalized electron-hole pairs is responsible for the ultrafast initial excitation of the modes., Comment: 16 pages, 16 figures. To be published in Physical Review Letters: https://journals.aps.org/prl/accepted/c1070Y74M8b18063d9cd0221b000631d50ef7a249

Published
2021
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6. Time-Resolved XUV absorption spectroscopy and magnetic circular dichroism at the Ni $M_{2,3}$-edges

Author

Hennes, Marcel, Rösner, Benedikt, Chardonnet, Valentin, Chiuzbaian, Gheorghe S., Delaunay, Renaud, Döring, Florian, Guzenko, Vitaliy A., Hehn, Michel, Jarrier, Romain, Kleibert, Armin, Lebugle, Maxime, Lüning, Jan, Merhe, Aladine, Naumenko, Denys, Nikolov, Ivaylo P., Lopez-Quintas, Ignacio, Pedersoli, Emanuele, Savchenko, Tatiana, Watts, Benjamin, Zangrando, Marco, David, Christian, Capotondi, Flavio, Vodungbo, Boris, and Jal, Emmanuelle

Subjects
Condensed Matter - Materials Science
Abstract

Ultrashort optical pulses can trigger a variety of non-equilibrium processes in magnetic thin films affecting electrons and spins on femtosecond timescales. In order to probe the charge and magnetic degrees of freedom simultaneously, we developed an x-ray streaking technique that has the advantage of providing a jitter-free picture of absorption cross section changes. In this paper, we present an experiment based on this approach which we performed using five photon probing energies at the Ni $M_{2,3}$-edges. This allowed us to retrieve the absorption and magnetic circular dichroism time traces, yielding detailed information on transient modifications of electron and spin populations close to the Fermi level. Our findings suggest that the observed charge and magnetic dynamics both depend on the XUV probing wavelength, and can be described, at least qualitatively, by assuming ultrafast energy shifts of the electronic and magnetic elemental absorption resonances, as reported in recent work. However, our analysis also hints at more complex changes, highlighting the need for further experimental and theoretical analysis in order to gain a thorough understanding of the interplay of electronic and spin degrees of freedom in optically excited magnetic thin films.

Published
2020
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7. SAXSDOG: open software for real-time azimuthal integration of 2D scattering images

Author

Burian, Max, Meisenbichler, Christian, Naumenko, Denys, and Amenitsch, Heinz

Subjects
Computer Science - Other Computer Science, Electrical Engineering and Systems Science - Image and Video Processing, Physics - Instrumentation and Detectors
Abstract

In-situ small- and wide-angle scattering experiments at synchrotrons often result in massive amounts of data within seconds only. Especially during such beamtimes, processing of the acquired data online, so without mentionable delay, is key to obtain feedback on failure or success of the experiment. We thus developed SAXSDOG, a python based environment for real-time azimuthal integration of large-area scattering-images. The software is primarily designed for dedicated data-pipelines: once a scattering image is transferred from the detector onto the storage-unit, it is automatically integrated and pre-evaluated using integral parameters within milliseconds. The control and configuration of the underlying server-based processes is done via a graphical user interface SAXSLEASH, which visualizes the resulting 1D data together with integral classifiers in real time. SAXSDOG further includes a portable 'take-home' version for users that runs on standalone computers, enabling its use in labs or at the preferred workspace., Comment: Source-code available at https://github.com/maxburian/SAXS_py3

Published
2020

8. Simultaneous two-color snapshot view on ultrafast charge and spin dynamics in a Fe-Cu-Ni tri-layer

Author

Rösner, Benedikt, Vodungbo, Boris, Chardonnet, Valentin, Döring, Florian, Guzenko, Vitaliy A., Hennes, Marcel, Kleibert, Armin, Lebugle, Maxime, Lüning, Jan, Mahne, Nicola, Merhe, Aladine, Naumenko, Denys, Nikolov, Ivaylo P., Lopez-Quintas, Ignacio, Pedersoli, Emanuele, Ribič, Primož R., Savchenko, Tatiana, Watts, Benjamin, Zangrando, Marco, Capotondi, Flavio, David, Christian, and Jal, Emmanuelle

Subjects
Condensed Matter - Materials Science, Physics - Instrumentation and Detectors, Physics - Optics
Abstract

Ultrafast phenomena on a femtosecond timescale are commonly examined by pump-probe experiments. This implies multiple measurements where the sample under investigation is pumped with a short light pulse and then probed with a second pulse at various time delays to follow its dynamics. Recently, the principle of streaking extreme ultraviolet (XUV) pulses in the temporal domain has enabled recording the dynamics of a system within a single pulse. However, separate pump-probe experiments at different absorption edges still lack a unified timing, when comparing the dynamics in complex systems. Here we report on an experiment using a dedicated optical element and the two-color emission of the FERMI XUV free-electron laser to follow the charge and spin dynamics in composite materials at two distinct absorption edges, simultaneously. The sample, consisting of ferromagnetic Fe and Ni layers, separated by a Cu layer, is pumped by an infrared laser and probed by a two-color XUV pulse with photon energies tuned to the M edges of these two transition metals. The experimental geometry intrinsically avoids any timing uncertainty between the two elements and unambiguously reveals an approximately 100 fs delay of the magnetic response with respect to the electronic excitation for both Fe and Ni. This delay shows that the electronic and spin degrees of freedom are decoupled during the demagnetization process. These observations underline the importance of simultaneous investigation of the temporal response of both charge and spin in multi-component materials. In a more general scenario, the experimental approach can be extended to continuous energy ranges, promising the development of jitter-free transient absorption spectroscopy in the XUV and soft X-ray regimes.

Published
2020
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9. A DNA origami plasmonic sensor with environment-independent read-out

Author

Masciotti, Valentina, Piantanida, Luca, Naumenko, Denys, Amenitsch, Heinz, Fanetti, Mattia, Valant, Matjaž, Lei, Dongsheng, Ren, Gang, and Lazzarino, Marco

Subjects
Biological Sciences, Engineering, Industrial Biotechnology, Bioengineering, Genetics, Nanotechnology, Generic health relevance, DNA origami, plasmonic sensor, molecular detection, gold nanoparticle, Nanoscience & Nanotechnology
Abstract

DNA origami is a promising technology for its reproducibility, flexibility, scalability and biocompatibility. Among the several potential applications, DNA origami has been proposed as a tool for drug delivery and as a contrast agent, since a conformational change upon specific target interaction may be used to release a drug or produce a physical signal, respectively. However, its conformation should be robust with respect to the properties of the medium in which either the recognition or the read-out take place, such as pressure, viscosity and any other unspecific interaction other than the desired target recognition. Here we report on the read-out robustness of a tetragonal DNA-origami/gold-nanoparticle hybrid structure able to change its configuration, which is transduced in a change of its plasmonic properties, upon interaction with a specific DNA target. We investigated its response when analyzed in three different media: aqueous solution, solid support and viscous gel. We show that, once a conformational variation is produced, it remains unaffected by the subsequent physical interactions with the environment.

Published
2019

12. Perovskite-type superlattices from lead halide perovskite nanocubes

Author

Cherniukh, Ihor, Rainò, Gabriele, Stöferle, Thilo, Burian, Max, Travesset, Alex, Naumenko, Denys, Amenitsch, Heinz, Erni, Rolf, Mahrt, Rainter F., Bodnarchuk, Maryna I., and Kovalenko, Maksym V.

Subjects
Lead compounds -- Usage -- Chemical properties -- Mechanical properties, Perovskite -- Usage -- Chemical properties -- Mechanical properties, Nanoparticles -- Production processes -- Materials, Halides -- Usage -- Chemical properties -- Mechanical properties, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Atomically defined assemblies of dye molecules (such as H and J aggregates) have been of interest for more than 80 years because of the emergence of collective phenomena in their optical spectra.sup.1-3, their coherent long-range energy transport, their conceptual similarity to natural light-harvesting complexes.sup.4,5, and their potential use as light sources and in photovoltaics. Another way of creating versatile and controlled aggregates that exhibit collective phenomena involves the organization of colloidal semiconductor nanocrystals into long-range-ordered superlattices.sup.6. Caesium lead halide perovskite nanocrystals.sup.7-9 are promising building blocks for such superlattices, owing to the high oscillator strength of bright triplet excitons.sup.10, slow dephasing (coherence times of up to 80 picoseconds) and minimal inhomogeneous broadening of emission lines.sup.11,12. So far, only single-component superlattices with simple cubic packing have been devised from these nanocrystals.sup.13. Here we present perovskite-type (ABO.sub.3) binary and ternary nanocrystal superlattices, created via the shape-directed co-assembly of steric-stabilized, highly luminescent cubic CsPbBr.sub.3 nanocrystals (which occupy the B and/or O lattice sites), spherical Fe.sub.3O.sub.4 or NaGdF.sub.4 nanocrystals (A sites) and truncated-cuboid PbS nanocrystals (B sites). These ABO.sub.3 superlattices, as well as the binary NaCl and AlB.sub.2 superlattice structures that we demonstrate, exhibit a high degree of orientational ordering of the CsPbBr.sub.3 nanocubes. They also exhibit superfluorescence--a collective emission that results in a burst of photons with ultrafast radiative decay (22 picoseconds) that could be tailored for use in ultrabright (quantum) light sources. Our work paves the way for further exploration of complex, ordered and functionally useful perovskite mesostructures. Through precise structural engineering, perovskite nanocrystals are co-assembled with other nanocrystal materials to form a range of binary and ternary perovskite-type superlattices that exhibit superfluorescence., Author(s): Ihor Cherniukh [sup.1] [sup.2] , Gabriele Rainò [sup.1] [sup.2] , Thilo Stöferle [sup.3] , Max Burian [sup.4] , Alex Travesset [sup.5] , Denys Naumenko [sup.6] , Heinz Amenitsch [sup.6] [...]

Published
2021
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13. Two-dimensional perovskites with alternating cations in the interlayer space for stable light-emitting diodes

Author

Zhang Yiyue, Keshavarz Masoumeh, Debroye Elke, Fron Eduard, Rodríguez González Miriam Candelaria, Naumenko Denys, Amenitsch Heinz, Van de Vondel Joris, De Feyter Steven, Heremans Paul, Roeffaers Maarten B. J., Qiu Weiming, Pradhan Bapi, and Hofkens Johan

Subjects
alternating interlayer cations, light-emitting diodes, stability, two-dimensional perovskites, Physics, QC1-999
Abstract

Lead halide perovskites have attracted tremendous attention in photovoltaics due to their impressive optoelectronic properties. However, the poor stability of perovskite-based devices remains a bottleneck for further commercial development. Two-dimensional perovskites have great potential in optoelectronic devices, as they are much more stable than their three-dimensional counterparts and rapidly catching up in performance. Herein, we demonstrate high-quality two-dimensional novel perovskite thin films with alternating cations in the interlayer space. This innovative perovskite provides highly stable semiconductor thin films for efficient near-infrared light-emitting diodes (LEDs). Highly efficient LEDs with tunable emission wavelengths from 680 to 770 nm along with excellent operational stability are demonstrated by varying the thickness of the interlayer spacer cation. Furthermore, the best-performing device exhibits an external quantum efficiency of 3.4% at a high current density (J) of 249 mA/cm2 and remains above 2.5% for a J up to 720 mA cm−2, leading to a high radiance of 77.5 W/Sr m2 when driven at 6 V. The same device also shows impressive operational stability, retaining almost 80% of its initial performance after operating at 20 mA/cm2 for 350 min. This work provides fundamental evidence that this novel alternating interlayer cation 2D perovskite can be a promising and stable photonic emitter.

Published
2021
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14. Orthogonal stimulation of structural transformations in photo-responsive MOF films through linker functionalization.

Author

Klokic, Sumea, Marmiroli, Benedetta, Naumenko, Denys, Birarda, Giovanni, Dal Zilio, Simone, Velásquez-Hernández, Miriam de J., Falcaro, Paolo, Vaccari, Lisa, and Amenitsch, Heinz

Subjects
ENERGY storage, STRUCTURAL dynamics, CHLORINE
Abstract

Controlling the magnitude of structural dynamics in flexible MOF films by an applied stimulus is largely desired for specific applications such as energy storage. Herein, by introducing chlorine substituents in an azobenzene-infiltrated Cl-DMOF-1 film structure, a significantly slowed structural response is obtained upon photo-switching of the system. [ABSTRACT FROM AUTHOR]

Published
2024
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15. Symmetry-resolved CO desorption and oxidation dynamics on O/Ru(0001) probed at the C K-edge by ultrafast x-ray spectroscopy.

Author

LaRue, Jerry, Liu, Boyang, Rodrigues, Gabriel L. S., Liu, Chang, Garrido Torres, Jose Antonio, Schreck, Simon, Diesen, Elias, Weston, Matthew, Ogasawara, Hirohito, Perakis, Fivos, Dell'Angela, Martina, Capotondi, Flavio, Ball, Devon, Carnahan, Conner, Zeri, Gary, Giannessi, Luca, Pedersoli, Emanuele, Naumenko, Denys, Amann, Peter, and Nikolov, Ivaylo

Subjects
X-ray spectroscopy, OXIDATION of carbon monoxide, TIME-resolved spectroscopy, FEMTOSECOND pulses, DESORPTION, FEMTOSECOND lasers, DIPOLE-dipole interactions, OXIDATION states
Abstract

We report on carbon monoxide desorption and oxidation induced by 400 nm femtosecond laser excitation on the O/Ru(0001) surface probed by time-resolved x-ray absorption spectroscopy (TR-XAS) at the carbon K-edge. The experiments were performed under constant background pressures of CO (6 × 10−8 Torr) and O2 (3 × 10−8 Torr). Under these conditions, we detect two transient CO species with narrow 2π* peaks, suggesting little 2π* interaction with the surface. Based on polarization measurements, we find that these two species have opposing orientations: (1) CO favoring a more perpendicular orientation and (2) CO favoring a more parallel orientation with respect to the surface. We also directly detect gas-phase CO2 using a mass spectrometer and observe weak signatures of bent adsorbed CO2 at slightly higher x-ray energies than the 2π* region. These results are compared to previously reported TR-XAS results at the O K-edge, where the CO background pressure was three times lower (2 × 10−8 Torr) while maintaining the same O2 pressure. At the lower CO pressure, in the CO 2π* region, we observed adsorbed CO and a distribution of OC–O bond lengths close to the CO oxidation transition state, with little indication of gas-like CO. The shift toward "gas-like" CO species may be explained by the higher CO exposure, which blocks O adsorption, decreasing O coverage and increasing CO coverage. These effects decrease the CO desorption barrier through dipole–dipole interaction while simultaneously increasing the CO oxidation barrier. [ABSTRACT FROM AUTHOR]

Published
2022
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16. Noncollinear, inelastic four-wave mixing in the extreme ultraviolet

Author

Mincigrucci, Riccardo, primary, Cannizzo, Andrea, additional, capotondi, flavio, additional, Cinquegrana, Paolo, additional, Cucini, Riccardo, additional, Dallari, Francesco, additional, Danailov, M, additional, de Ninno, Giovanni, additional, Di Mitri, Simone, additional, Feurer, Thomas, additional, Foglia, Laura, additional, Frey, Hans-Martin, additional, Manfredda, Michele, additional, Maznev, Alexei, additional, Monaco, Giulio, additional, Naumenko, Denys, additional, Nikolov, Ivaylo, additional, Ollmann, Zoltán, additional, Paltanin, Ettore, additional, Pamfilidis, Georgios, additional, Pedersoli, Emanuele, additional, Principi, Emiliano, additional, Réhault, Julien, additional, Simoncig, Alberto, additional, Svetina, Cristian, additional, Knopp, Gregor, additional, Masciovecchio, Claudio, additional, and Bencivenga, Filippo, additional

Published
2023
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17. Time-resolved chemically-selective spectroscopic investigation of the α-Fe2O3/Al redox reaction

Author

Mincigrucci, Riccardo, primary, Paltanin, Ettore, additional, Pelli-Cresi, Jacopo, additional, Principi, Emiliano, additional, De Angelis, Dario, additional, Foglia, Laura, additional, Garzella, David, additional, Kurdi, Gabor, additional, Manfredda, Michele, additional, Simoncig, Alberto, additional, Masciovecchio, Claudio, additional, Naumenko, Denys, additional, Bencivenga, Filippo, additional, Lee, Wonseok, additional, and Cushing, Scott, additional

Published
2023
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18. EIGER2 hybrid-photon-counting X-ray detectors for advanced synchrotron diffraction experiments

Author

Donath, Tilman, primary, Šišak Jung, Dubravka, additional, Burian, Max, additional, Radicci, Valeria, additional, Zambon, Pietro, additional, Fitch, Andrew N., additional, Dejoie, Catherine, additional, Zhang, Bingbing, additional, Ruat, Marie, additional, Hanfland, Michael, additional, Kewish, Cameron M., additional, van Riessen, Grant A., additional, Naumenko, Denys, additional, Amenitsch, Heinz, additional, Bourenkov, Gleb, additional, Bricogne, Gerard, additional, Chari, Ashwin, additional, and Schulze-Briese, Clemens, additional

Published
2023
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19. Implication of the double-gating mode in a hybrid photon counting detector for measurements of transient heat conduction in GaAs/AlAs superlattice structures

Author

Naumenko, Denys, primary, Burian, Max, additional, Marmiroli, Benedetta, additional, Haider, Richard, additional, Radeticchio, Andrea, additional, Wagner, Lucas, additional, Piazza, Luca, additional, Glatt, Lisa, additional, Brandstetter, Stefan, additional, Dal Zilio, Simone, additional, Biasiol, Giorgio, additional, and Amenitsch, Heinz, additional

Published
2023
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20. Mn Doping in Low-Dimensional Perovskites: A Switch for Controlling Dopant and Host Emission

Author

Pradhan, Bapi, primary, Keshavarz, Masoumeh, additional, Zhang, Yiyue, additional, Sun, Li, additional, Marquez, Carlos, additional, Smolders, Simon, additional, De Vos, Dirk, additional, Fron, Eduard, additional, Van de Vondel, Joris, additional, Naumenko, Denys, additional, Amenitsch, Heinz, additional, Debroye, Elke, additional, Roeffaers, Maarten BJ, additional, and Hofkens, Johan, additional

Published
2023
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23. Strongly Confined CsPbBr3 Quantum Dots as Quantum Emitters and Building Blocks for Rhombic Superlattices

Author

Boehme, Simon C., primary, Bodnarchuk, Maryna I., additional, Burian, Max, additional, Bertolotti, Federica, additional, Cherniukh, Ihor, additional, Bernasconi, Caterina, additional, Zhu, Chenglian, additional, Erni, Rolf, additional, Amenitsch, Heinz, additional, Naumenko, Denys, additional, Andrusiv, Hordii, additional, Semkiv, Nazar, additional, John, Rohit Abraham, additional, Baldwin, Alan, additional, Galkowski, Krzysztof, additional, Masciocchi, Norberto, additional, Stranks, Samuel D., additional, Rainò, Gabriele, additional, Guagliardi, Antonietta, additional, and Kovalenko, Maksym V., additional

Published
2023
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24. Atom-Specific Probing of Electron Dynamics in an Atomic Adsorbate by Time-Resolved X-Ray Spectroscopy

Author

Schreck, Simon, primary, Diesen, Elias, additional, Dell’Angela, Martina, additional, Liu, Chang, additional, Weston, Matthew, additional, Capotondi, Flavio, additional, Ogasawara, Hirohito, additional, LaRue, Jerry, additional, Costantini, Roberto, additional, Beye, Martin, additional, Miedema, Piter S., additional, Halldin Stenlid, Joakim, additional, Gladh, Jörgen, additional, Liu, Boyang, additional, Wang, Hsin-Yi, additional, Perakis, Fivos, additional, Cavalca, Filippo, additional, Koroidov, Sergey, additional, Amann, Peter, additional, Pedersoli, Emanuele, additional, Naumenko, Denys, additional, Nikolov, Ivaylo, additional, Raimondi, Lorenzo, additional, Abild-Pedersen, Frank, additional, Heinz, Tony F., additional, Voss, Johannes, additional, Luntz, Alan C., additional, and Nilsson, Anders, additional

Published
2022
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26. Superfluorescent Multicomponent Nanocrystal Superlattices from Lead Halide Perovskite Nanocubes

Author

Cherniukh, Ihor, primary, Kovalenko, Maksym, additional, Sekh, Taras, additional, Stöferle, Thilo, additional, Burian, Max, additional, Travesset, Alex, additional, Athanasiou, Modestos, additional, Manoli, Andreas, additional, Rainò, Gabriele, additional, Shynkarenko, Yevhen, additional, Naumenko, Denys, additional, Amenitsch, Heinz, additional, Itskos, Grigorios, additional, Erni, Rolf, additional, Mahrt, Rainer, additional, Bodnarchuk, Maryna, additional, and John, Rohit, additional

Published
2022
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27. Strongly Confined CsPbBr3 Perovskite Quantum Dots as Quantum Emitters and Building Blocks for Highly Ordered Rhombic Superlattices

Author

Boehme, Simon, primary, Kovalenko, Maksym, additional, Burian, Max, additional, Bertolotti, Federica, additional, Cherniukh, Ihor, additional, Bernasconi, Caterina, additional, Zhu, Chenglian, additional, Amenitsch, Heinz, additional, Naumenko, Denys, additional, Bodnarchuk, Maryna, additional, Semkiv, Nazar, additional, John, Rohit Abraham, additional, Baldwin, Alan, additional, Galkowski, Krzystof, additional, Masciocchi, Norberto, additional, Stranks, Samuel, additional, Rainò, Gabriele, additional, Guagliardi, Antonietta, additional, and Andrusiv, Hordii, additional

Published
2022
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29. Unravelling the origin of the capacitance in nanostructured nitrogen-doped carbon - NiO hybrid electrodes deposited with laser

Author

Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, European Commission, CSIC - Unidad de Recursos de Información Científica para la Investigación (URICI), García Lebière, Pablo [0000-0001-9687-0227], Rajak, Piu [0000-0002-8728-7459], Ciancio, Regina [0000-0003-1739-3763], García Lebière, Pablo, Gyorgy, Eniko, Logofatu, Constantin, Naumenko, Denys, Amenitsch, Heinz, Rajak, Piu, Ciancio, Regina, Pérez del Pino, Ángel, Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, European Commission, CSIC - Unidad de Recursos de Información Científica para la Investigación (URICI), García Lebière, Pablo [0000-0001-9687-0227], Rajak, Piu [0000-0002-8728-7459], Ciancio, Regina [0000-0003-1739-3763], García Lebière, Pablo, Gyorgy, Eniko, Logofatu, Constantin, Naumenko, Denys, Amenitsch, Heinz, Rajak, Piu, Ciancio, Regina, and Pérez del Pino, Ángel

Abstract

The full knowledge of the charge storage mechanisms occurring in complex composite electrodes is key for the straightforward development of advanced electrochemical capacitors. In this work, hybrid electrodes composed of reduced graphene oxide, multiwall carbon nanotubes and NiO nanostructures were fabricated through reactive inverse matrix assisted pulsed laser evaporation technique. Nitrogen doping of the carbon nanostructures was carried out by introducing ammonia, urea and melamine precursors in the target. The N-doped graphene electrodes exhibited a significant capacitance enhancement as compared to non-doped ones. This fact is commonly ascribed to faradaic mechanisms. However, our structural-compositional studies point to a significant change of the structural configuration of the composites at the nanoscale upon the nitrogen functionalization as the source of the electrodes’ capacitance enhancement. The composites fabricated with urea precursor exhibited the highest capacitance, and this fact was associated with the presence of pyridinic N groups that triggered the formation of a high amount of structural defects (vacancies – boundaries) and microporosity, not observed in the samples synthesized with other precursors that mainly contained pyrrolic-graphitic N.

Published
2022

30. An Integrated Bulk and Surface Modification Strategy for Gas-Quenched Inverted Perovskite Solar Cells with Efficiencies Exceeding 22%

Author

Zhang, Xin, Qiu, Weiming, Song, Wenya, Hawash, Zafer, Wang, Yaxin, Pradhan, Bapi, Zhang, Yiyue, Naumenko, Denys, Amenitsch, Heinz, Moons, Ellen, Merckx, Tamara, Aguirre, Aranzazu, Abdulraheem, Yaser, Aernouts, Tom, Zhan, Yiqiang, Kuang, Yinghuan, Hofkens, Johan, Poortmans, Jef, Zhang, Xin, Qiu, Weiming, Song, Wenya, Hawash, Zafer, Wang, Yaxin, Pradhan, Bapi, Zhang, Yiyue, Naumenko, Denys, Amenitsch, Heinz, Moons, Ellen, Merckx, Tamara, Aguirre, Aranzazu, Abdulraheem, Yaser, Aernouts, Tom, Zhan, Yiqiang, Kuang, Yinghuan, Hofkens, Johan, and Poortmans, Jef

Abstract

Inverted perovskite solar cells (PSCs) prepared by the antisolvent method have achieved power conversion efficiencies (PCEs) of over 23%, but they are not ideal for device upscaling. In contrast, gas-quenched PSCs offer great potential for upscaling, but their performance still lags behind. Herein, the gas-quenched films through both surface and bulk modifications are upgraded. First, a novel surface modifier, benzylammonium thiocyanate, is found to allow remarkably improved surface properties, but the PCE gain is limited by the existence of longitudinally multiple grains. Thus, methylammonium chloride additive as a second modifier to realize monolithic grains is further utilized. Such an integrated strategy enables the average open-circuit voltage of the gas-quenched PSCs to increase from 1.08 to 1.15 V, leading to a champion PCE of 22.3%. Moreover, the unencapsulated device shows negligible degradation after 150 h of maximum power point operation under simulated 1 sun illumination in N2.

Published
2022
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32. Strongly Confined CsPbBr3 Quantum Dots as Quantum Emitters and Building Blocks for Rhombic Superlattices.

Author

Boehme, Simon C., Bodnarchuk, Maryna I., Burian, Max, Bertolotti, Federica, Cherniukh, Ihor, Bernasconi, Caterina, Zhu, Chenglian, Erni, Rolf, Amenitsch, Heinz, Naumenko, Denys, Andrusiv, Hordii, Semkiv, Nazar, John, Rohit Abraham, Baldwin, Alan, Galkowski, Krzysztof, Masciocchi, Norberto, Stranks, Samuel D., Rainò, Gabriele, Guagliardi, Antonietta, and Kovalenko, Maksym V.

Published
2023
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33. Structural Diversity in Multicomponent Nanocrystal Superlattices Comprising Lead Halide Perovskite Nanocubes

Author

Cherniukh, Ihor, primary, Sekh, Taras V., additional, Rainò, Gabriele, additional, Ashton, Olivia J., additional, Burian, Max, additional, Travesset, Alex, additional, Athanasiou, Modestos, additional, Manoli, Andreas, additional, John, Rohit Abraham, additional, Svyrydenko, Mariia, additional, Morad, Viktoriia, additional, Shynkarenko, Yevhen, additional, Montanarella, Federico, additional, Naumenko, Denys, additional, Amenitsch, Heinz, additional, Itskos, Grigorios, additional, Mahrt, Rainer F., additional, Stöferle, Thilo, additional, Erni, Rolf, additional, Kovalenko, Maksym V., additional, and Bodnarchuk, Maryna I., additional

Published
2022
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34. An Integrated Bulk and Surface Modification Strategy for Gas‐Quenched Inverted Perovskite Solar Cells with Efficiencies Exceeding 22%

Author

Zhang, Xin, primary, Qiu, Weiming, additional, Song, Wenya, additional, Hawash, Zafer, additional, Wang, Yaxin, additional, Pradhan, Bapi, additional, Zhang, Yiyue, additional, Naumenko, Denys, additional, Amenitsch, Heinz, additional, Moons, Ellen, additional, Merckx, Tamara, additional, Aguirre, Aranzazu, additional, Abdulraheem, Yaser, additional, Aernouts, Tom, additional, Zhan, Yiqiang, additional, Kuang, Yinghuan, additional, Hofkens, Johan, additional, and Poortmans, Jef, additional

Published
2022
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39. Nanoscale Thermoelasticity in Silicon Nitride Membranes: Implications for Thermal Management

Author

Milloch, Alessandra, primary, Mincigrucci, Riccardo, additional, Capotondi, Flavio, additional, De Angelis, Dario, additional, Foglia, Laura, additional, Kurdi, Gabor, additional, Naumenko, Denys, additional, Pedersoli, Emanuele, additional, Pelli-Cresi, Jacopo S., additional, Simoncig, Alberto, additional, Wehinger, Björn, additional, Masciovecchio, Claudio, additional, and Bencivenga, Filippo, additional

Published
2021
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41. Ultrafast Adsorbate Excitation Probed with Subpicosecond-Resolution X-Ray Absorption Spectroscopy

Author

Diesen, Elias, primary, Wang, Hsin-Yi, additional, Schreck, Simon, additional, Weston, Matthew, additional, Ogasawara, Hirohito, additional, LaRue, Jerry, additional, Perakis, Fivos, additional, Dell’Angela, Martina, additional, Capotondi, Flavio, additional, Giannessi, Luca, additional, Pedersoli, Emanuele, additional, Naumenko, Denys, additional, Nikolov, Ivaylo, additional, Raimondi, Lorenzo, additional, Spezzani, Carlo, additional, Beye, Martin, additional, Cavalca, Filippo, additional, Liu, Boyang, additional, Gladh, Jörgen, additional, Koroidov, Sergey, additional, Miedema, Piter S., additional, Costantini, Roberto, additional, Heinz, Tony F., additional, Abild-Pedersen, Frank, additional, Voss, Johannes, additional, Luntz, Alan C., additional, and Nilsson, Anders, additional

Published
2021
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43. Monodisperse Long-Chain Sulfobetaine-Capped CsPbBr₃ Nanocrystals and Their Superfluorescent Assemblies

Author

Krieg, Franziska, Sercel, Peter C., Burian, Max, Andrusiv, Hordii, Bodnarchuk, Maryna I., Stöferle, Thilo, Mahrt, Rainer F., Naumenko, Denys, Amenitsch, Heinz, Rainò, Gabriele, and Kovalenko, Maksym V.

Abstract

Ligand-capped nanocrystals (NCs) of lead halide perovskites, foremost fully inorganic CsPbX₃ NCs, are the latest generation of colloidal semiconductor quantum dots. They offer a set of compelling characteristics—large absorption cross section, as well as narrow, fast, and efficient photoluminescence with long exciton coherence times—rendering them attractive for applications in light-emitting devices and quantum optics. Monodisperse and shape-uniform, broadly size-tunable, scalable, and robust NC samples are paramount for unveiling their basic photophysics, as well as for putting them into use. Thus far, no synthesis method fulfilling all these requirements has been reported. For instance, long-chain zwitterionic ligands impart the most durable surface coating, but at the expense of reduced size uniformity of the as-synthesized colloid. In this work, we demonstrate that size-selective precipitation of CsPbBr₃ NCs coated with a long-chain sulfobetaine ligand, namely, 3-(N,N-dimethyloctadecylammonio)-propanesulfonate, yields monodisperse and sizable fractions (>100 mg inorganic mass) with the mean NC size adjustable in the range between 3.5 and 16 nm and emission peak wavelength between 479 and 518 nm. We find that all NCs exhibit an oblate cuboidal shape with the aspect ratio of 1.2 × 1.2 × 1. We present a theoretical model (effective mass/k·p) that accounts for the anisotropic NC shape and describes the size dependence of the first and second excitonic transition in absorption spectra and explains room-temperature exciton lifetimes. We also show that uniform zwitterion-capped NCs readily form long-range ordered superlattices upon solvent evaporation. In comparison to more conventional ligand systems (oleic acid and oleylamine), supercrystals of zwitterion-capped NCs exhibit larger domain sizes and lower mosaicity. Both kinds of supercrystals exhibit superfluorescence at cryogenic temperatures—accelerated collective emission arising from the coherent coupling of the emitting dipoles.

Published
2021

44. Ultrafast Adsorbate Excitation Probed with Subpicosecond-Resolution X-Ray Absorption Spectroscopy

Author

Diesen, Elias, Wang, Hsin-Yi, Schreck, Simon, Weston, Matthew, Ogasawara, Hirohito, LaRue, Jerry, Perakis, Fivos, Dell’Angela, Martina, Capotondi, Flavio, Giannessi, Luca, Pedersoli, Emanuele, Naumenko, Denys, Nikolov, Ivaylo, Raimondi, Lorenzo, Spezzani, Carlo, Beye, Martin, Cavalca, Filippo, Liu, Boyang, Gladh, Jörgen, Koroidov, Sergey, Miedema, Piter S., Costantini, Roberto, Heinz, Tony F., Abild-Pedersen, Frank, Voss, Johannes, Luntz, Alan C., Nilsson, Anders, Diesen, Elias, Wang, Hsin-Yi, Schreck, Simon, Weston, Matthew, Ogasawara, Hirohito, LaRue, Jerry, Perakis, Fivos, Dell’Angela, Martina, Capotondi, Flavio, Giannessi, Luca, Pedersoli, Emanuele, Naumenko, Denys, Nikolov, Ivaylo, Raimondi, Lorenzo, Spezzani, Carlo, Beye, Martin, Cavalca, Filippo, Liu, Boyang, Gladh, Jörgen, Koroidov, Sergey, Miedema, Piter S., Costantini, Roberto, Heinz, Tony F., Abild-Pedersen, Frank, Voss, Johannes, Luntz, Alan C., and Nilsson, Anders

Published
2021
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46. Time-resolved observation of transient precursor state of CO on Ru(0001) using carbon K-edge spectroscopy

Author

Wang, Hsin-Yi, Schreck, Simon, Weston, Matthew, Liu, Chang, Ogasawara, Hirohito, LaRue, Jerry, Perakis, Fivos, Dell’Angela, Martina, Capotondi, Flavio, Giannessi, Luca, Pedersoli, Emanuele, Naumenko, Denys, Nikolov, Ivaylo, Raimondi, Lorenzo, Spezzani, Carlo, Beye, Martin, Cavalca, Filippo, Liu, Boyang, Gladh, Jörgen, Koroidov, Sergey, Miedema, Piter S., Costantini, Roberto, Pettersson, Lars G. M., Nilsson, Anders, Wang, Hsin-Yi, Schreck, Simon, Weston, Matthew, Liu, Chang, Ogasawara, Hirohito, LaRue, Jerry, Perakis, Fivos, Dell’Angela, Martina, Capotondi, Flavio, Giannessi, Luca, Pedersoli, Emanuele, Naumenko, Denys, Nikolov, Ivaylo, Raimondi, Lorenzo, Spezzani, Carlo, Beye, Martin, Cavalca, Filippo, Liu, Boyang, Gladh, Jörgen, Koroidov, Sergey, Miedema, Piter S., Costantini, Roberto, Pettersson, Lars G. M., and Nilsson, Anders

Abstract

The transient dynamics of carbon monoxide (CO) molecules on a Ru(0001) surface following femtosecond optical laser pump excitation has been studied by monitoring changes in the unoccupied electronic structure using an ultrafast X-ray free-electron laser (FEL) probe. The particular symmetry of perpendicularly chemisorbed CO on the surface is exploited to investigate how the molecular orientation changes with time by varying the polarization of the FEL pulses. The time evolution of spectral features corresponding to the desorption precursor state was well distinguished due to the narrow line-width of the C K-edge in the X-ray absorption (XA) spectrum, illustrating that CO molecules in the precursor state rotated freely and resided on the surface for several picoseconds. Most of the CO molecules trapped in the precursor state ultimately cooled back down to the chemisorbed state, while we estimate that ∼14.5 ± 4.9% of the molecules in the precursor state desorbed into the gas phase. It was also observed that chemisorbed CO molecules diffused over the metal surface from on-top sites toward highly coordinated sites. In addition, a new “vibrationally hot precursor” state was identified in the polarization-dependent XA spectra.

Published
2020
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47. Time-Resolved XUV Absorption Spectroscopy and Magnetic Circular Dichroism at the Ni M2,3-Edges

Author

Hennes, Marcel, primary, Rösner, Benedikt, additional, Chardonnet, Valentin, additional, Chiuzbaian, Gheorghe S., additional, Delaunay, Renaud, additional, Döring, Florian, additional, Guzenko, Vitaliy A., additional, Hehn, Michel, additional, Jarrier, Romain, additional, Kleibert, Armin, additional, Lebugle, Maxime, additional, Lüning, Jan, additional, Malinowski, Gregory, additional, Merhe, Aladine, additional, Naumenko, Denys, additional, Nikolov, Ivaylo P., additional, Lopez-Quintas, Ignacio, additional, Pedersoli, Emanuele, additional, Savchenko, Tatiana, additional, Watts, Benjamin, additional, Zangrando, Marco, additional, David, Christian, additional, Capotondi, Flavio, additional, Vodungbo, Boris, additional, and Jal, Emmanuelle, additional

Published
2020
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50. Simultaneous two-color snapshot view on ultrafast charge and spin dynamics in a Fe-Cu-Ni tri-layer

Author

Rösner, Benedikt, primary, Vodungbo, Boris, additional, Chardonnet, Valentin, additional, Döring, Florian, additional, Guzenko, Vitaliy A., additional, Hennes, Marcel, additional, Kleibert, Armin, additional, Lebugle, Maxime, additional, Lüning, Jan, additional, Mahne, Nicola, additional, Merhe, Aladine, additional, Naumenko, Denys, additional, Nikolov, Ivaylo P., additional, Lopez-Quintas, Ignacio, additional, Pedersoli, Emanuele, additional, Ribič, Primož R., additional, Savchenko, Tatiana, additional, Watts, Benjamin, additional, Zangrando, Marco, additional, Capotondi, Flavio, additional, David, Christian, additional, and Jal, Emmanuelle, additional

Published
2020
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