Relevant bibliographies by topics / Static and time resolved spectroscopies

Academic literature on the topic 'Static and time resolved spectroscopies'

Author: Grafiati
Published: 11 March 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Contents

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Static and time resolved spectroscopies.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Static and time resolved spectroscopies"

1

Niedzwiedzki, Dariusz M., Mojgan Kouhnavard, Yifan Diao, Julio M. D'Arcy, and Pratim Biswas. "Spectroscopic investigations of electron and hole dynamics in MAPbBr3 perovskite film and carrier extraction to PEDOT hole transport layer." Physical Chemistry Chemical Physics 23, no. 23 (2021): 13011–22. http://dx.doi.org/10.1039/d1cp00658d.

Full text
Abstract:
Characterization of photophysical properties of MAPbBr3 perovskite film with application of various static and time-resolved spectroscopies and evaluation of hole extraction process in the FTO/RVPP-PEDOT/MAPbBr3 architecture.
APA, Harvard, Vancouver, ISO, and other styles
2

Curtright, Aimee E., and James K. McCusker. "Static and Time-Resolved Spectroscopic Studies of Low-Symmetry Ru(II) Polypyridyl Complexes." Journal of Physical Chemistry A 103, no. 35 (September 1999): 7032–41. http://dx.doi.org/10.1021/jp9919415.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Rastogi, Vinay, Usha Rao, Shivanand Chaurasia, Chakkalakkal Davis Sijoy, Vinayak Mishra, Shashank Chaturvedi, and Mukul Narayan Deo. "Time-Resolved Vibrational Spectroscopy of Polytetrafluoroethylene Under Laser-Shock Compression." Applied Spectroscopy 71, no. 12 (August 11, 2017): 2643–52. http://dx.doi.org/10.1177/0003702817726542.

Full text
Abstract:
Shock-wave-induced high pressure and nanosecond time-resolved Raman spectroscopic experiments were performed to examine the dynamic response of polytetrafluoroethylene (PTFE) in confinement geometry targets. Time-resolved Raman spectroscopy was used to observe the pressure-induced molecular and chemical changes on nanosecond time scale. Raman spectra were measured as a function of shock pressure in the 1.2–2.4 GPa range. Furthermore, the symmetric stretching mode at 729 cm–1 of CF2 was compared to corresponding static high-pressure measurements carried out in a diamond anvil cell, to see if any general trend can be established. The symmetric stretching mode of CF2 at 729 cm–1 is the most intense Raman transition in PTFE and is very sensitive to change in pressure. Therefore, it can also be utilized as a pressure gauge for large amplitude shock wave compression experiments. A maximum blueshift of 12 cm–1 for the 729 cm–1 vibrational mode has been observed for the present experimental pressure range. A comparative study on the similarities and differences from the earlier work has been done in detail. One-dimensional radiation hydrodynamic simulations were performed to validate our shock compression results and are in very good agreement.
APA, Harvard, Vancouver, ISO, and other styles
4

Thekku Veedu, Sreevidya. "Ultrafast Dynamical Study Using Time-resolved Laue Diffraction." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C766. http://dx.doi.org/10.1107/s205327331409233x.

Full text
Abstract:
Electron transfer reactions are fundamental processes in chemistry and also in biology [1-3]. Light harvesting complexes are functional centers in plants where sunlight is converted into chemical energy. In this, optical excitation in a chromophore unit leads to the transfer of electrons within the system. However, due to the complexity of the biological photo-reaction centre, recent spectroscopic efforts have concentrated on a smaller chemical model which share characteristic with their biological counter parts. A promising model is the so-called D-A (donor-acceptor) systems, which are chemically synthetic molecules with electron transfer capabilities. The electrical conductivity is a function of the optical state of the system. An optically switching diode is an interesting application of donor-acceptor molecules. We aimed to determine photo-induced structural changes in Pyrene-N,N-dimethylaniline (PyDMA). Static structures for many molecules are available at high resolution but the mechanism by which these molecules function and the structures of intermediate states often remain elusive. Knowledge of the geometry of molecular excited states at atomic resolution is crucial for a full understanding of photo-induced chemical processes. Time-resolved X-ray diffraction (TR-XRD) using polychromatic synchrotron radiation allows a detailed study of the time evolution of structural intermediates and short living states of chemical systems at wide range of time-scales, drawing a complete picture of the photo-induced charge transfer process. Investigation of photo-excitation processes in molecular single crystals, where the initial photo-excitation processes occur on extremely short time-scales (femto-/picosecond time domain) and have been in the focus of scientific investigations due to their possible applications, e.g. as optical switches.
APA, Harvard, Vancouver, ISO, and other styles
5

Mottin, Stephane, Canh Tran-Minh, Pierre Laporte, Raymond Cespuglio, and Michel Jouvet. "Fiber-Optic Time-Resolved Fluorescence Sensor for in Vitro Serotonin Determination." Applied Spectroscopy 47, no. 5 (May 1993): 590–97. http://dx.doi.org/10.1366/0003702934067180.

Full text
Abstract:
At pH 7 and with the excitation at wavelengths above 315 nm, previously unreported fluorescence of 5-HT (5-hydroxytryptamine) is observed. Two fluorescence bands were observed for 5-HT; the first emits at around 390 nm with an associated lifetime near 1 ns, and the other (well known) emits at 340 nm with an associated lifetime of 2.7 ns. With both static and time-resolved fluorescences, the spectral and temporal effects of the excitation wavelength were studied between 285 and 340 nm. With these basic spectroscopic properties as a starting point, a fiber-optic chemical sensor (FOCS) was developed in order to measure 5-HT with a single-fiber configuration, nitrogen laser excitation, and fast digitizing techniques. Temporal effects including fluorescence of the optical fiber were studied and compared with measurements both directly in cuvette and through the fiber-optic sensor. Less than thirty seconds are required for each measurement. A detection limit of 5-HT is reached in the range of 5 μM. Our system, with an improved sensitivity, could therefore be a possible and convenient “tool” for in vivo determination of 5-HT.
APA, Harvard, Vancouver, ISO, and other styles
6

Sciortino, Alice, Roberto Pecorella, Marco Cannas, and Fabrizio Messina. "Effect of Halogen Ions on the Photocycle of Fluorescent Carbon Nanodots." C — Journal of Carbon Research 5, no. 4 (October 24, 2019): 64. http://dx.doi.org/10.3390/c5040064.

Full text
Abstract:
Carbon dots (C-dots) are well-known for their strong sensitivity to the environment, which reflects on intensity and shape changes of their fluorescence, induced by various interacting ions and molecules in solution. Although these interactions have been extensively studied in the last few years, especially in view of their possible sensing applications, the existing works have mostly focused on the quenching of C-dot fluorescence induced by metal cations. In fact, these latter easily bind to C-dots surfaces, which are negatively charged in most cases, promoting an electron transfer from the surface to them. Much less is known from the literature on the effect induced on C-dots by prototypical negative species in solutions, motivating more systematic studies on this different class of interactions. Here, we analyzed the effect of halogen ions on the fluorescence of C-dots, by combining steady-state optical absorption and photoluminescence, time-resolved fluorescence and femtosecond pump/probe spectroscopy. We demonstrate a quenching effect of C-dots fluorescence in the presence of halogen ions, which becomes more and more pronounced with increasing atomic number of the halogens, being negligible for chloride, appreciable for bromide and stronger for iodide. We find that quenching is mostly static, due to the binding of halogen ions on suitable surface sites at C-dots surfaces, while collisional quenching becomes obvious only at very high iodide concentrations. Finally, nanosecond and femtosecond time-resolved spectroscopies provide information on the quenching mechanism and time scales. Based on these data, we propose that the fluorescent state is deactivated by intersystem crossing to a dark triplet state, induced by close-range interactions with the heaviest halogen ions.
APA, Harvard, Vancouver, ISO, and other styles
7

Noda, Isao, A. E. Dowrey, and Curtis Marcott. "A Spectrometer for Measuring Time-Resolved Infrared Linear Dichroism Induced by a Small-Amplitude Oscillatory Strain." Applied Spectroscopy 42, no. 2 (February 1988): 203–16. http://dx.doi.org/10.1366/0003702884428310.

Full text
Abstract:
A spectrometer for detecting dynamic infrared linear dichroism (DIRLD) induced by a small-amplitude oscillatory strain is described. The strain-induced dynamic variations of absorbance and linear dichroism, as well as the normal static absorbance and dichroism, are measured simultaneously as functions of IR wavenumber, temperature, and strain frequency. The phase (temporal) relationships between the dynamic optical signals and the applied strain are also obtained. The instrument is sensitive enough to detect dynamic optical signals on the order of 10−4 absorbance units with a time resolution of about 14 μs. The dynamic dichroism signals arise from the strain-induced temporary reorientation of dipole-transition moments associated with the molecular vibrations of chemical functional groups. Both the rate and extent of reorientations are strongly influenced by the local molecular environment of the functional groups. Because of the specificity of IR absorbance bands to the individual submolecular structures, DIRLD spectroscopy is especially suited for the study of the intra- and intermolecular interactions and the detection of subtle changes in the local molecular environment. Example DIRLD spectra of atactic polystyrene are presented to demonstrate the potential utility of this spectroscopic technique.
APA, Harvard, Vancouver, ISO, and other styles
8

Abraham, Suja, and Vellaichamy Parthasarathy. "INTERACTION OF COPPER OXIDE NANOPARTICLES WITH BOVINE SERUM ALBUMIN BY SPECTROSCOPIC STUDIES." International Journal of Pharmacy and Pharmaceutical Sciences 10, no. 5 (May 1, 2018): 35. http://dx.doi.org/10.22159/ijpps.2018v10i5.24877.

Full text
Abstract:
Objective: Since structural changes of adsorbed protein are necessary for cellular uptake of nanoparticles (NPs) it is of prime importance to know about structural changes of bovine serum albumin (BSA) when it interacts with CuO NPs–a potential new antitumor drug.Methods: CuO NPs prepared by sol-gel technique were characterized by x-ray diffraction (XRD) and tunneling electron microscope (TEM) techniques. The conformational changes induced by CuO NPs on BSA were studied by various spectroscopic techniques such as steady state and time-resolved fluorescence measurements. The changes in fluorescence emission parameters such as fluorescence intensity, fluorescence emission maximum and lifetimes of fluorescent residues in BSA were studied.Results: XRD analysis showed the average particle size as 32 nm. The TEM micrograph showed particles of different size varying from 10 to 45 nm. Fluorescence quenching was confirmed due to a decrease in fluorescence intensity of CuO NPs–BSA complex. The analysis of lifetime measurements indicated BSA contained two tryptophan (trp) residues that fluoresced in different environments. Static quenching mechanism was confirmed by time-resolved measurements when BSA interacted with CuO NPs.Conclusion: Minor structural changes of BSA protein were observed during the interaction studies.
APA, Harvard, Vancouver, ISO, and other styles
9

Rao, Usha, Shivanand Chaurasia, C. D. Sijoy, Vinayak Mishra, and M. N. Deo. "In Situ Raman Spectroscopic Studies of Liquid Carbon Tetrachloride (CCl4) Under Static and Laser-Driven Shock Compression." Applied Spectroscopy 73, no. 12 (August 12, 2019): 1420–27. http://dx.doi.org/10.1177/0003702819856372.

Full text
Abstract:
High pressure (up to ∼2.2 GPa) Raman scattering studies were performed in carbon tetrachloride (CCl4) under static and dynamic compressions using diamond anvil cell (DAC) and laser-driven shock methods, respectively, and their results are compared. The laser-driven shock experiments were conducted in a glass-confined target geometry. The symmetric stretching mode ν1, symmetric bending mode ν2, and asymmetric bending mode ν4 blueshifts with pressure. Mode Gruneisen parameters were obtained for the above Raman modes. Time-resolved Raman spectroscopic (TRRS) studies were performed under laser-driven shock compression at different delay times. Shock velocity deduced from the intensity ratios of Raman signal scattered from unshocked and shocked regions of symmetric stretching mode is in agreement with the one obtained from one-dimensional hydrodynamic simulations.
APA, Harvard, Vancouver, ISO, and other styles
10

Chinnathambi, Shanmugavel, Subramani Karthikeyan, Devadasan Velmurugan, Nobutaka Hanagata, Prakasarao Aruna, and Singaravelu Ganesan. "Investigations on the Interactions of 5-Fluorouracil with Herring Sperm DNA: Steady State/Time Resolved and Molecular Modeling Studies." Biophysical Reviews and Letters 10, no. 02 (June 2015): 115–33. http://dx.doi.org/10.1142/s1793048015500034.

Full text
Abstract:
In the present study, the interaction of 5-Fluorouracil with herring sperm DNA is reported using spectroscopic and molecular modeling techniques. This binding study of 5-FU with hs-DNA is of paramount importance in understanding chemico–biological interactions for drug design, pharmacy and biochemistry without altering the original structure. The challenge of the study was to find the exact binding mode of the drug 5-Fluorouracil with hs-DNA. From the absorption studies, a hyperchromic effect was observed for the herring sperm DNA in the presence of 5-Fluorouracil and a binding constant of 6.153 × 103 M-1 for 5-Fluorouracil reveals the existence of weak interaction between the 5-Fluorouracil and herring sperm DNA. Ethidium bromide loaded herring sperm DNA showed a quenching in the fluorescence intensity after the addition of 5-Fluorouracil. The binding constants for 5-Fluorouracil stranded DNA and competitive bindings of 5-FU interacting with DNA–EB systems were examined by fluorescence spectra. The Stern–Volmer plots and fluorescence lifetime results confirm the static quenching nature of the drug-DNA complex. The binding constant Kb was 2.5 × 104 L mol-1 and the number of binding sites are 1.17. The 5-FU on DNA system was calculated using double logarithmic plot. From the Forster nonradiative energy transfer study it has been found that the distance of 5-FU from DNA was 4.24 nm. In addition to the spectroscopic results, the molecular modeling studies also revealed the major groove binding as well as the partial intercalation mode of binding between the 5-Fluorouracil and herring sperm DNA. The binding energy and major groove binding as -6.04 kcal mol-1 and -6.31 kcal mol-1 were calculated from the modeling studies. All the testimonies manifested that binding modes between 5-Fluorouracil and DNA were evidenced to be groove binding and in partial intercalative mode.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Static and time resolved spectroscopies"

1

Capogrosso, Valentina. "Dimensionality and ordering effects on the electronic structure of low dimensional strongly correlated electron transition metal oxides." Doctoral thesis, Università degli studi di Trieste, 2013. http://hdl.handle.net/10077/8587.

Full text
Abstract:
2011/2012
Nel vasto scenario dei materiali fortemente correlati gli ossidi dei metalli di transizione hanno attratto enorme interesse a causa delle loro interessanti proprietà fisiche, come ad esempio, la superconduttività nei cuprati e la magnetoresistenza gigante nelle manganiti. In particolare, il mio interesse è stato rivolto ad una specifica classe di materiali, per i quali la dimensionalità è il parametro più importante. Le attività sperimentali sono state focalizzate verso due sistemi: la manganite Pr0.5Ca1.5MnO4 dopata a metà e a strato singolo (hd-PCMO) e la famiglia dei rutenati Srn+1RunO3n+1 (n=1,2,3). Entrambi questi sistemi esibiscono fenomeni affascinanti strettamente legati ad una complicata interazione tra i gradi di libertà del reticolo cristallino, di spin, di carica, ed orbitale, dove la dimensionalità cristallina gioca un ruolo cruciale. Con il mio progetto di dottorato ho studiato alcune proprietà dei materiali sopracitati per mezzo di spettroscopie con raggi X, come l’emissione risonante di raggi X (RXES) e l’assorbimento di raggi X (XAS) statico e risolto in tempo. Tutte le misure sono state condotte utilizzando la linea di luce BACH (linea di luce per dicroismo avanzato) dell’anello di accumulazione Elettra della Elettra-Sincrotrone Trieste. Il sistema hd-PCMO presenta una transizione di ordinamento di carica ed orbitale (CO-O) ad una temperatura TCO relativamente elevate, i.e. 340 K, accompagnata da una distorsione strutturale ortorombica, dove i portatori di carica fortemente correlati eg del Mn si ordinano in sotto-reticoli cristallografici separati (stato di carica ordinato) con un carattere orbitale specifico (stato di ordinamento orbitale). Inoltre, hd-PCMO presenta anche una risposta reticolare anomala ad una temperatura 20 K sopra la temperatura di Neél TN, che è associata ad un inatteso accoppiamento spin-reticolo. Poiché mancava uno studio degli stati elettronici non occupati del PCMO, misure dipendenti dalla temperatura per mezzo del dicroismo lineare (XLD) sono state realizzate alle soglie K dell’ossigeno e L3 del Mn al fine di spiegare il ruolo della topologia orbitale dei Mn 3d – O 2p. I dati sperimentali, supportati da calcoli ab-initio LDA+U, ci danno informazioni sulla ridistribuzione di carica e sui cambiamenti delle p-DOS alla transizione CO-O e a quella antiferromagnetica (AFM). I risultati ottenuti mostrano che l’interazione competitiva tra la distorsione locale atomica, necessaria per permettere l’ordinamento CO, e le dinamiche di carica del meccanismo di hopping regolano lo stato orbitale dei portatori di carica. Inoltre, sulla base di studi teorici che predicono la formazione di fasi orbitali e strutturali transienti “nascoste” per mezzo della stimolazione ottica, abbiamo studiato le DOS non occupate dello stato metastabile indotto otticamente nel PCMO per mezzo della XAS risolta in tempo, che offre uno strumento unico per misurare le DOS proiettate in sito ed in simmetria degli stati metastabili della materia. Le misure XAS risolte in tempo alla soglia K dell’ossigeno sono state realizzate per mezzo di un nuovo apparato sperimentale disponibile a BACH, che si basa su un laser Ti:zaffiro (impulsi di pompa) con tasso di ripetizione variabile sincronizzato con gli impulsi a 500 MHz dei raggi X (impulsi di sonda). L’evoluzione temporale degli spettri XAS attraverso la transizione CO-O fotoindotta otticamente risulta differente rispetto alle misure XAS adiabatiche, dimostrando l’esistenza di una “fase nascosta” fotoindotta nel PCMO, la cui natura è ancora sconosciuta. I rutenati Srn+1RunO3n+1 (n=1,2,3) sono emersi come una famiglia importante di peroschiti a causa dell’evoluzione inattesa e senza precedenti dal comportamento anisotropico ferro- o metamagnetico del Sr4Ru3O10 (n=3) dipendente dalla direzione del campo magnetico, all’ aumentato paramagnetismo di Pauli vicino all’ordinamento magnetico del Sr3Ru2O7 (n=2) e, infine, alla superconduttività a bassa temperature in Sr2RuO4 (n=1). Nonostante vengano riportati numerosi studi sulle proprietà strutturali e magnetiche di questi composti, l’evoluzione delle strutture elettroniche occupate e non occupate non è stata investigata in dettaglio. Quindi, la dipendenza delle strutture elettroniche e l’ibridizzazione degli stati 2p dell’ossigeno sono state investigate combinando la spettroscopia XAS alla soglia K dell’ossigeno (transizione 2p-1s) dipendente dalla polarizzazione e la spettroscopia RXES. Una sezione del capitolo 3 è dedicata ad illustrare un setup sperimentale sviluppato recentemente per esperimenti XAS risolti in tempo sfruttando la struttura temporale “multibunch” dell’anello di accumulazione del sincrotrone. Sfruttando le potenzialità di questo setup, la transizione di superficie semiconduttore-metallo nel germanio cristallino è stata fotoindotta ed il set completo di dati viene discusso. Lo schema della mia tesi di dottorato è il seguente. Il primo capitolo presenta una panoramica dell’intero lavoro. Il secondo capitolo è diviso in due sezioni. La prima sezione introduce il lettore alla fisica orbitale ed alle transizioni di fase elettroniche nei metalli di transizione a ridotta dimensionalità, con un excursus sullo stato dell’arte dei composti 3d del manganese e la famiglia 4d dei rutenati. L’intento della seconda sezione è quello di spiegare l’importanza delle tecniche spettroscopiche nei raggi X molli come strumenti per investigare le proprietà elettroniche dei solidi. La descrizione delle spettroscopie XAS e RXES vengono riviste più in dettaglio nel capitolo 3, che include anche la descrizione dell’apparato sperimentale della beamline BACH e del laboratorio T-ReX al Sincrotrone Elettra. Il capitolo 4 è dedicato alla teoria funzionale di densità (DFT) ed alla approssimazione locale di densità più U (LDA+U) ed ai dettagli del modello del sistema hd-PCMO. Il capitolo 5, che presenta i casi studiati, è diviso in due sezioni: il caso del PCMO, che include le misure XAS statiche e risolte in tempo, ed il caso della serie Ruddlesden-Popper dei rutenati di Sr investigate per mezzo della RXES. Nel capitolo finale vengono presentati i commenti finali su questo lavoro.
In the vast scenario of strongly correlated-electron materials transition-metal oxides have attracted enormous interest because of their interesting physical properties, including for example, superconductivity in cuprates and colossal magnetoresistance in manganites. In particular, my interest was directed to a particular class of materials, whose dimensionality is the most defining material parameter. With my Ph.D. project I deepened into some physical properties of these materials by means of core-levels spectroscopies such as resonant x ray emission (RXES) and static and time-resolved x ray absorption (XAS). All the measurements have been carried out at the beamline BACH (Beamline for Advanced diCHroism) at the Elettra light source facility in Trieste. The experimental activities focused on two case-study systems: the single layered half-doped Pr0.5Ca1.5MnO4 (hd-PCMO) and the layered Srn+1RunO3n+1 (n=1,2,3) family. Both these systems exhibit fascinating phenomena intimately related to a complicated interplay between the crystal lattice, spin, charge, and orbital degrees of freedom, where crystal dimensionality plays a crucial role. hd-PCMO exhibits a charge-orbital ordering (CO-O) transition at a remarkably high TCO, slightly above room temperature, accompanied by an orthorhombic structural distortion, where the strongly correlated Mn eg charge carriers order onto separate crystallographic sub-lattices (charge-ordered state) with a specific orbital character (orbital ordered state). Furthermore, hd-PCMO also displays an anomalous lattice response at temperatures 20K above the Neél temperature TN, which is associated to an unexpected spin-lattice coupling. Since a study of the PCMO unoccupied electronic states was lacking, temperature dependence measurements by XAS linear dichroism (XLD) have been performed at the O-K and Mn-L3 thresholds in order to elucidate the role of Mn 3d - O 2p orbital topology. The experimental data, supported by ab-initio LDA+U, shed light on the charge redistribution and p-DOS changes at the CO-O and antiferromagnetic (AFM) transitions. The results obtained show that the competitive interplay between the local atomic distortion, necessary for accomodating the CO-ordering, and the charge dynamics of the hopping mechanism regulates the orbital state of the charge carriers. Furthermore, on the basis of theoretical studies that predict the formation of transient “hidden” orbital and structural phases by optical stimulation, we have studied the unoccupied DOS of the optically induced metastable state in PCMO by means of time resolved XAS, which offers a unique tool to measure site and symmetry projected DOS of metastable states in matter. Tr-XAS measurements at the O-K edge have been carried out by means of a novel experimental apparatus available at BACH, which is based on a variable repetition rate Ti:sapphire laser (pump pulse) synchronized with the ∼ 500 MHz X-ray photon pulses (probe pulses). The time evolution of the XAS lineshapes across the optically photoinduced CO-O transition results different respect to the adiabatic XAS measurements, demonstrating the existence of a photoinduced “hidden phase” in PCMO, whose nature is still unknown. The layered Srn+1RunO3n+1 (n=1,2,3) have emerged as an important family of perovskites because of the unexpected and unprecedented evolution from anisotropic ferro- or metamagnetic behavior of Sr4Ru3O10 (n=3) dependent on the direction of the magnetic field, enhanced Pauli paramagnetism close to magnetic order of Sr3Ru2O7 (n=2) and, finally, to low-temperature superconductivity in Sr2RuO4 (n=1). Although numerous studies have been reported on the structural and magnetic properties of these compounds, the evolution of the occupied and unoccupied electronic structures were not investigated in detail. Thus, the dependence of electronic structures and the hybridization of O 2p states have been investigated by combining polarization dependent O K (2p-1s transition) XAS and RXES spectroscopies. A section of the chapter 3 is dedicated to illustrate a newly developed experimental setup for time-resolved XAS experiments by exploiting the multibunch time structure of a synchrotron storage ring. By exploiting the capabilities of this setup, the surface semiconductor-metal transition in crystalline germanium has been photoinduced and the complete set of data discussed. The outline of my Ph.D. thesis is the following. The first chapter presents an overview of the entire work. The second chapter is divided into two sections. The first section introduces the reader into the orbital physics and the electronic phase transitions in low dimensional transition metal oxides, with an excursus on the state of the art of 3d manganese compounds and the family of 4d Ruthenates. The second section is aimed to explain the importance of soft x-ray spectroscopic techniques as tools to investigate the electronic properties of solids. The description of XAS and RXES are reviewed in more details in chapter 3, which includes also the description of the experimental apparatus of BACH beamline and T-ReX lab at the Elettra synchrotron light source. Chapter 4 is dedicated to the Density Functional Theory (DFT) and Local Density Approximation plus U (LDA+U) theories and to the details of the modelling of the hd-PCMO system. Chapter 5, which presents the cases studied, is divided into two sections: the case of PCMO, including static and time resolved XAS measurements, and the case of Ruddlesden-Popper series of Sr Ruthenates investigated by means of RXES. In the final chapter the concluding remarks on this work are presented.
XXV Ciclo
1983
APA, Harvard, Vancouver, ISO, and other styles
2

Pemasiri, Karunananda. "Investigation of zincblende, wurtzite, and mixed phase InP nanowires by photocurrent, photoluminescence and time-resolved photoluminescence spectroscopies." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1377873494.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Villamil, Franco Carolina. "Ultrafast dynamics of excitons and charge carriers in colloidal perovskite nanostructures studied by time-resolved optical spectroscopies." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASF012.

Full text
Abstract:
Les matériaux semiconducteurs de pérovskite halogénée se sont révélés très prometteurs en raison de leurs propriétés exceptionnelles et de leur capacité d’élaboration à faible coût. Malgré les progrès réalisés, une meilleure compréhension des dynamiques de relaxation et de recombinaison dans ces matériaux photo-actifs est nécessaire afin d’améliorer les performances des dispositifs opto-électroniques. Cette thèse porte sur la relaxation des porteurs de charge/excitons « chauds » après excitation au-dessus de la bande interdite, et la recombinaison Auger advenant après une excitation de forte puissance ou à haute énergie. La spectroscopie de fluorescence résolue en temps et d'absorption transitoire (AT) femtoseconde sont utilisées afin d’étudier les effets du confinement et de la composition sur ces processus, en particulier dans les nanoplaquettes (NPLs) colloïdales de pérovskite bidimensionnelles (2D), dont la synthèse a été développée et optimisée au préalable. Les dynamiques de relaxation ont été étudiées par AT en utilisant une méthode d'analyse globale où l'évolution temporelle des différentes compositions spectrales est modélisée suivant une cinétique de réactions séquentielles. Cette méthode a pu être appliquée afin de décrire efficacement la relaxation progressive dans les nanostructures de FAPbI₃ (FA= formamidinium) faiblement confinées, et a permis de dissocier les processus de retardement de relaxation à haute puissance d’excitation dus aux effets de « hot phonon bottleneck » et de ré-excitation par recombinaison Auger (RA). Par ailleurs, l'analyse globale de l’évolution spectrale a été essentielle afin d’examiner les dynamiques de relaxation dans les NPLs 2D à fort confinement quantique et diélectrique, présentant des effets Stark importants et une transition de bord de bande excitonique discrète. Comme dans les systèmes faiblement confinés, le taux de relaxation dans les NPLs diminue avec la puissance d'excitation. Cependant, il est plus rapide dans les systèmes présentant un confinement plus important, mettant alors en évidence l'absence de ”phonon bottleneck” intrinsèque. La nature des cations internes (FA, MA=méthylammonium ou Cs) n’influe pas ce taux, ni son évolution en puissance. Toutefois, les mesures dans les films de pérovskite 2D présentant une épaisseur de puits quantique équivalente, suggèrent un rôle des ligands de surface dans la capacité à libérer l'excès d'énergie dans l'environnement. Ensuite, les recombinaisons multi-excitoniques dominées par la RA non radiative ont été étudiées dans les NPLs de pérovskite 2D fortement confinées. Dû à la géométrie asymétrique de ces nanostructures et de la délocalisation limitée de l'exciton, le temps de RA dépend fortement de la densité d'excitons via la distance inter-exciton moyenne : A faible puissance d’excitation, la RA est limitée par la diffusion de l'exciton dans le plan 2D et se produit sur plusieurs centaines de picosecondes (dépendant ainsi de la géométrie de l'échantillon). En revanche, une puissance d'excitation élevée produit des excitons dont les fonctions d’onde se recouvrent spatialement, entraînant des temps de RA inférieurs à 10 ps. Finalement, les dynamiques excitoniques dans les NPLs 2D ont été mesurées par AT après excitation dans l’ultraviolet afin d'observer le processus de multiplication d’excitons. Ce dernier implique la génération de plusieurs excitons “géminés”, et donc proches spatialement, suite à l'absorption d'un unique photon de haute énergie
Halide perovskites have emerged as very promising photoactive materials due to their outstanding optoelectronic properties combined with low-cost processability. In spite of their successful implementation in photovoltaic or light-emitting devices, a deep understanding of the dynamics of relaxation and recombination is still missing in order to enhance the device performances. This thesis focuses on the study of two major fundamental processes occurring in colloidal halide perovskite nanostructures: the hot charge carrier/exciton relaxation (“cooling”), after excitation above the optical bandgap, and the non-radiative Auger recombination, taking place after high-fluence or high-photon energy excitation. In particular, time-resolved photoluminescence and femtosecond transient absorption spectroscopy were used to investigate the confinement and composition effects in strongly confined two-dimensional (2D) lead iodide perovskite nanoplatelets (NPLs), that were synthesized following the development and optimizations of colloidal methods. For the investigation of the cooling dynamics, a global analysis method based on single value decomposition was used, where the temporal evolution of the spectral lineshapes was modeled with a sequential kinetic scheme. This method was succesfully applied to effectively describe the continuous energy relaxation in weakly-confined thick FAPbI₃ nanoplates (FA=formamidinium) and allowed disantangleting the hot phonon bottleneck from the Auger reheating effects at high excitation fluence. Furthermore, the global analysis was essential to investigate the cooling dynamics in strongly confined 2D NPLs presenting large Stark effects and discrete excitonic band-edge transition far away from the continuum of states (exciton binding energy in several hundreds of meV). As in the weakly confined samples, the cooling rate of the NPLs decreases with the excitation fluence. However, it is faster in more-strongly confined samples, evidencing the absence of an intrinsic phonon bottleneck. Furthermore, the cooling rate and its evolution with the exciton density were found independent of the nature of the internal cations (FA, MA=methylammonium and Cs=cesium). However, when comparing with the rate measured in 2D layered perovskite thin film with equivalent quantum well thickness, the results strongly suggest a role of the surface ligands in the possibility to release the excess energy to the surrounding environment. This ligand-mediated relaxation mechanism becomes dominent in the thinner NPL samples with enhanced exciton/ligand vibrational mode coupling. Then, the multiple exciton recombination dominated by non-radiative Auger recombination (AR) was studied in the strongly-confined 2D perovskite NPLs. Due to the large asymmetric geometry and the limited exciton wavefunction delocalization, the AR rate strongly depends on the exciton density via the initial average inter-exciton distance. At low fluence, this distance is in several tens of nanometers such as the AR is limited by the exciton diffusion in the 2D plane. It thus occurs on a timescale of several hundreds of picoseconds and depends on the sample dimensionality (thickness and lateral sizes). In contrast, high excitation fluences produce “overlapping” excitons with inter-exciton distances of only a few times the exciton Bohr radius, resulting in AR times of less than 10 ps and independent of the NPL composition nor geometry. Finally, the exciton population dynamics of 2D NPLs after excitation in the ultraviolet was measured. The strong dependence of the AR with the inter-exciton distance allows the identification of multiple exciton generation (MEG), which involves the reaction of “geminate biexcitons” produced by the absorption of a single high-energy photon
APA, Harvard, Vancouver, ISO, and other styles
4

Hussain, Abid [Verfasser], and Nils [Akademischer Betreuer] Huse. "Theory and computation of time-resolved spectroscopies for molecular systems in complex environments / Abid Hussain ; Betreuer: Nils Huse." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2017. http://d-nb.info/1137323701/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Miki, Takeshi [Verfasser], and Marcus [Akademischer Betreuer] Motzkus. "Third- and Fifth-order Nonlinear Time-resolved Spectroscopies for Ultrafast Molecular Dynamics in Carotenoids / Takeshi Miki ; Betreuer: Marcus Motzkus." Heidelberg : Universitätsbibliothek Heidelberg, 2017. http://d-nb.info/1180986385/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Hieke, Florian [Verfasser], and Wilfried [Akademischer Betreuer] Wurth. "Electronic Excitations in Solids Studied with Static and Time Resolved X-ray Spectroscopy / Florian Hieke ; Betreuer: Wilfried Wurth." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2017. http://d-nb.info/1129874826/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Hua, Ying. "Structures auto-assemblées de guanines étudiées par spectroscopie optique résolue en temps." Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00873695.

Full text
Abstract:
Les brins d'ADN riches en guanine, comme ceux présents à l'extrémité des chromosomes humains, sont capables de s'associer entre eux pour former des structures G-quadruplexes, résultant de l'association de quatre guanines (G-tétrade). Ces structures sont actuellement l'objet d'un intérêt particulier pour le développement de nouvelles thérapies anti-cancéreuses et des applications potentielles pour l'électronique moléculaire. Il n'existe cependant que très peu d'études des propriétés photophysiques des G-quadruplexes. L'objectif de ce travail de thèse est d'étudier l'influence de la structrure des G-quadruplexes sur leurs propriétés photophysiques au moyen de la spectroscopie de fluorescence résolue en temps sur une gamme temporelle allant de la centaine de femtosecondes à la centaine de nanosecondes. Nous avons examiné l'effet de la taille de structures G-quadruplexes tétramoléculaires sur leurs propriétés photophysiques. Nous avons pu montrer que le caractère collectif des états ππ* des guanines est renforcé lorsque le nombre de tétrades augmente et qu'un transfert d'énergie ultra-rapide, en moins de 100 fs a lieu entre ces états. Nous avons ensuite mis en évidence le rôle des cations métalliques situés dans la cavité centrale des quadruplexes dans le processus de désactivation des états excités. En présence de K+, l'émission provient principalement des états délocalisée ππ* des guanines, alors qu'en présence de Na+, l'émission dominée par la contribution d'états excités à caractère de transfert de charge. Enfin, nous avons abordé l'effet de la topologie, en comparant les propriétés photophysiques des G-quadruplexes tétramoléculaires avec celles de structures formées par le repliement d'un simple brin d'ADN. Les différences observées peuvent s'expliquer par la rigidité accrue des structures simple-brins et l'orientation relative différente des tétrades qui détermine la force du couplage électronique entre les bases.
APA, Harvard, Vancouver, ISO, and other styles
8

Paul, Rajsekhar [Verfasser], Josef [Akademischer Betreuer] Wachtveitl, and C. Roy D. [Akademischer Betreuer] Lancaster. "From static difference to time-resolved spectroscopy of coupled electron and proton transfer in the quinol: fumarate reductase of Wolinella succinogenes / Rajsekhar Paul. Gutachter: Josef Wachtveitl ; C. Roy D. Lancaster." Frankfurt am Main : Univ.-Bibliothek Frankfurt am Main, 2011. http://d-nb.info/1044195150/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Khadeeva, Liya. "Photo-isomerization and photo-induced NO release in ruthenium nitrosyl compounds." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S067/document.

Full text
Abstract:
Ce travail de thèse est centré sur l'étude expérimentale de deux types de transformations photo-induites observées dans différents complexes métalliques (Fe, Ru, ...) à ligand nitrosyle: (i) la photo-isomérisation au cours de laquelle le ligand NO passe d'un état lié par l'azote (M-NO, état stable GS) à un état lié par l'oxygène (M-ON, état métastable MSI). C'est un processus réversible et un second état métastable, 'side-on' MSII est observable au cours du processus inverse, MSI --> 'side-on' MSII --> GS; (ii) la libération photo-induite du radical NO°. La photo-isomérisation a été étudiée dans le système [Ru(py)_4Cl(NO)](PF_6)_2.1/2H_2O (sur monocristal) par la diffraction des RX, l'absorption visible statique et l'absorption UV-Vis résolue en temps. Nous avons pu mettre en évidence un processus d'absorption de photons (473 nm) en deux étapes, suivre la dynamique des transformations directes et inverses par l'évolution des paramètres de maille et des l'absorption optique visible, caractériser structuralement l'état 'side-on' MSII. La nature de l'état intermédiaire, MSII, lors du processus direct semble être différente de l'état 'side-on' mais la très faible population de cet intermédiaire n'a pas permis de trancher définitivement. Le rôle de la molécule d'eau dans la maille du complexe [Ru(py)_4Cl(NO)](PF_6)_2.1/2H_2O a été testé par diffraction des RX sur les échantillons hydratées, déshydratées et réhydratées. L'effet de déshydratation sur l'évolution des paramètres de maille et sur la génération d'espèces MSII au cours de la photo-commutation inverse, MSI --> MSII --> GS, est présenté. La libération photo-induite du radical NO° a été étudiée dans une solution d'acétonitrile du complexe trans-(Cl,Cl)[Ru^{II}(FT)Cl_2(NO)]PF_6 par spectroscopies d'absorption UV-Vis et Mi-IR, statiques et résolues en temps. En observant la dynamique ultra-rapide de la photo-transformation, nous avons mis en évidence un processus d'absorption de photons (406 nm) en deux étapes. La nature de l'état intermédiaire est discuté par rapport à de récents calculs théoriques et au processus de photo-isomérisation
This Ph. D. thesis is focused on the experimental study of two photo-induced processes observed in various [ML_5NO] complexes, where M=Fe, Ru, ..., L=CN, Cl, ... : (i) photo-isomerization, where the system goes from N-bound state (M-NO, stable GS state) to O-bound state (M-ON, metastable MSI state) and a second metastable state, 'side-on' MSII is observed during the inverse photo-transformation, MSI --> 'side-on' MSII --> GS; (ii) photo-induced release of NO° radical. The photo-isomerization is investigated in single crystals of [Ru(py)_4Cl(NO)](PF_6)_2.1/2H_2O compound by means of X-Ray diffraction, steady state visible and time-resolved UV-visible absorption spectroscopies. During these experiments we observed the evidence of a two-step photon absorption process (473 nm), we followed the dynamics of direct and inverse photo-switching by the evolution of lattice parameters and absorption in the visible range and we caracterised the structure of 'side-on' MSII state. The nature of MSII in the direct photo-switching, GS --> MSI, seems to be different from the 'side-on' configuration, however, we do not have a direct access to this state due to its low population. The role of water molecule in the unit cell of [Ru(py)_4Cl(NO)](PF_6)_2.1/2H_2O complex was tested by X-Ray diffraction studies on hydrated, dehydrated and rehydrated samples. The effect of sample dehydration on the unit cell parameters evolution and MSII species generation during the MSI --> MSII --> GS inverse photo-switching is presented. The photo-induced NO° release in trans-(Cl,Cl)[Ru^{II}(FT)Cl_2(NO)]PF_6 system in acetonitrile solution is studied by the UV-visible and mid-IR absorption spectroscopies, both steady state and time-resolved. By observing the ultra-fast dynamics of photo-transformation we evidenced a two-step photon absorption process (406 nm). The nature of intermediate state is discussed within the recent theoretical calculations and the photo-isomerization process
APA, Harvard, Vancouver, ISO, and other styles
10

Bourhis, Kevin. "Photostructuration par laser infrarouge femtoseconde de verres photosensibles de phosphates de zinc, d'argent et de gallium." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2011. http://tel.archives-ouvertes.fr/tel-00661392.

Full text
Abstract:
La focalisation de lasers à impulsions ultra-brèves dans les verres a montré des potentialités importantes pour la structuration des matériaux transparents, permettant d'envisager la réalisation de dispositifs tout-optique en une seule étape. Le développement de nouveaux matériaux vitreux de composition 40P2O5-55ZnO-xAg2O-(5-x)Ga2O3 permet de tirer avantage de la photosensibilité de l'ion Ag+ pour la structuration de propriétés optiques au cœur du matériau. L'augmentation du taux d'oxyde de gallium provoque la dépolymérisation des chaînes phosphates et s'accompagne de la réticulation du réseau vitreux par des polyèdres GaOx (4 ≤ x ≤ 6). La formation de des derniers n'affecte pas les propriétés d'émission lumineuses, qui proviennent des ions Ag+ isolés dans différents sites cristallographiques. L'exposition des verres sous faisceau laser intense provoque la formation de centres-trous Ag2+, responsables d'une luminescence intense, et de pièges d'électrons Ag0. Un traitement thermique consécutif ou simultané à l'irradiation provoque la dissociation de ces espèces, et s'accompagne de la formation d'agrégats moléculaires de la forme Agmx+. L'utilisation d'un laser femtoseconde à haute cadence permet, en combinant création de paires électron-trou et élévation locale de la température, de réaliser des architectures complexes conduisant à la structuration de propriétés optiques.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Static and time resolved spectroscopies"

1

Kliger, David S., Eefei Chen, and Robert A. Goldbeck. "Nanosecond Time-Resolved Natural and Magnetic Chiroptical Spectroscopies." In Comprehensive Chiroptical Spectroscopy, 179–201. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2012. http://dx.doi.org/10.1002/9781118120187.ch7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Kirkwood, Jason C., Christoph Scheurer, Tatsuya Minami, Vladimir Chernyak, and Shaul Mukamel. "Energy funneling in the dendrimeric nanostar probed by time-resolved nonlinear spectroscopies." In Ultrafast Phenomena XII, 610–12. Berlin, Heidelberg: Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/978-3-642-56546-5_180.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Ito, Osamu. "Chapter 8. Electron-Transfer Processes of Fullerenes Studied with Time-Resolved Spectroscopies." In Nanoscience & Nanotechnology Series, 270–328. Cambridge: Royal Society of Chemistry, 2011. http://dx.doi.org/10.1039/9781849732956-00270.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Harford, Jeff, and John M. Squire. "Static and Time-resolved X-ray Diffraction Studies of Fish Muscle." In Molecular Mechanisms in Muscular Contraction, 287–320. London: Macmillan Education UK, 1990. http://dx.doi.org/10.1007/978-1-349-09814-9_10.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Venanzi, Mariano, Emanuela Gatto, Gianfranco Bocchinfuso, Antonio Palleschi, Lorenzo Stella, Chiara Baldini, Fernando Formaggio, Claudio Toniolo, and Basilio Pispisa. "Monitoring Peptide Folding by Time-Resolved Spectroscopies: the Effect of a Single Gly to Aib Susbtitution." In Advances in Experimental Medicine and Biology, 47–48. New York, NY: Springer New York, 2009. http://dx.doi.org/10.1007/978-0-387-73657-0_21.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Masotti, Lanfranco, Paolo Cavatorta, Arthur G. Szabo, Giorgio Farruggia, and Giovanna Sartor. "Conformational Flexibility of the Polypeptide Hormone Bombesin: Time Resolved and Static Fluorescence Studies." In Fluorescent Biomolecules, 173–93. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4684-5619-6_12.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Hunter, D. B., W. P. Gates, P. M. Bertsch, and K. M. Kemner. "Degradation of Tetraphenylboron at Hydrated Smectite Surfaces Studied by Time Resolved IR and X-ray Absorption Spectroscopies." In ACS Symposium Series, 282–300. Washington, DC: American Chemical Society, 1999. http://dx.doi.org/10.1021/bk-1998-0715.ch014.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Hienerwadel, Rainer, Eliane Nabedryk, Jacques Breton, Werner Kreutz, and Werner Mäntele. "Time-Resolved Infrared and Static FTIR Studies of QA → QB Electron Transfer in Rhodopseudomonas Viridis Reaction Centers." In The Photosynthetic Bacterial Reaction Center II, 163–72. Boston, MA: Springer US, 1992. http://dx.doi.org/10.1007/978-1-4615-3050-3_20.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Deveaud, B. "Time-Resolved Optical Spectroscopies." In Encyclopedia of Condensed Matter Physics, 206–14. Elsevier, 2005. http://dx.doi.org/10.1016/b0-12-369401-9/00672-0.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Goldbeck, Robert A., and David S. Kliger. "[7] Nanosecond time-resolved absorption and polarization dichroism spectroscopies." In Metallobiochemistry Part C: Spectroscopic and Physical Methods for Probing Metal Ion Environments in Metalloenzymes and Metalloproteins, 147–77. Elsevier, 1993. http://dx.doi.org/10.1016/0076-6879(93)26009-x.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Static and time resolved spectroscopies"

1

Myers, Anne B., and Alan E. Johnson. "Electronic and Vibrational Dephasing in Solution by Dynamic Symmetry Breaking." In International Conference on Ultrafast Phenomena. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/up.1996.fe.25.

Full text
Abstract:
All spectroscopies, whether explicitly time-resolved or steady-state, are sensitive to fluctuations in the spectroscopic environment of the chromophore on the time scale of the radiation-matter interaction(s). Simple "two-state jump" models that assume random hopping between just two spectroscopically distinct environments have been well studied. Such models can provide some qualitative insight into the influence of fluctuations on a particular spectroscopy even if the actual system accesses a continuous distribution of states, as is usually the case for chromophores in liquids. The usual two-state models assume that the states differ in their transition frequencies to one or more accessible excited states. In linear spectroscopies, such models predict the well-known coalescence from two discrete resonances to a single broad one which then motionally narrows as the fluctuation rate increases. For multiphoton spectroscopies the effects are more complicated; in particular, for monochromatically excited spontaneous emission, increasing the fluctuation rate causes evolution from a sharp, "resonance Raman-like" spectrum to one having increasing contributions from broad emission.1 The transition frequency fluctuations constitute a source of electronic pure dephasing at the level of the chromophore's density matrix, generating a "fluorescence" component to the emission.
APA, Harvard, Vancouver, ISO, and other styles
2

Bawendi, Moungi G. "Size Dependent Spectroscopy of CdSe Nanocrystallites." In Spectral Hole-Burning and Related Spectroscopies: Science and Applications. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/shbs.1994.fb1.

Full text
Abstract:
Semiconductor crystallites which are 10's of Angstroms show a striking evolution of electronic properties with size.1 These particles (quantum dots) are large enough to exhibit a crystalline core, but small enough that solid state electronic and vibrational band structure is not yet developed. We use a recently developed synthetic method for the synthesis of high quality nanometer size (1-10 nm) II-VI semiconductor crystallites with narrow size distributions (σ <5%), emphasizing CdSe.2 Optical characterization of their electronic structure using pump-probe techniques, luminescence, and DC Stark techniques reveals both molecular and bulk-like characteristics as well as properties which are unique to nanometer size crystallites. We observe a number of discrete electronic transitions, assign them as coming from the creation of delocalized "particle-in-a-sphere" states using the theory of Ref. 3, and study their dependence on crystallite diameter.4 The Stark experiments are also compatible with the absorbing states as delocalized symmetric states. We use time resolved fluoresence line narrowing spectroscopy to study the dynamics of electron-hole recombination. We observe significant changes in electron-LO phonon coupling with time, temperature, and crystallite size and suggest that the electron-hole pair dynamics following photoexcitation are dominated by surface effects which are especially important in the smaller crystallites where a large fraction of the atoms are "surface" atoms.5
APA, Harvard, Vancouver, ISO, and other styles
3

Long, J. P., B. S. Itchkawitz, and M. N. Kabler. "Photoelectron Spectroscopy of Laser Excited Surfaces Using Synchrotron Radiation." In High Resolution Fourier Transform Spectroscopy. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/hrfts.1994.wd2.

Full text
Abstract:
For over a decade, laser pump-probe photoelectron spectroscopy (PES) has proven unique in its ability to determine the energy, momentum, and population dynamics of surface and near-surface excited states in solids.1,2 Practitioners most often generate the requisite probe UV pulse with laser upconversion techniques. The broader and continuous tunability of synchrotron radiation (SR) make it also an attractive source, albeit with reduced ultimate time resolution, and, in fact, SR is employed for time resolved spectroscopies spanning the far infrared to the hard x-ray regimes.3 We have developed a laser-pump, SR-probe PES system with nanosecond resolution at the National Synchrotron Light Source, and here we summarize results from GaAs, C60 films, and Si. This work anticipates specific areas where new photon probes, particularly femtosecond high harmonic generation4, UV-FEL’s, and 3rd generation SR sources, will find important applications.
APA, Harvard, Vancouver, ISO, and other styles
4

Bressler, Christian. "Time-Resolved X-Ray Spectroscopies and Scattering." In International Conference on Ultrafast Structural Dynamics. Washington, D.C.: OSA, 2012. http://dx.doi.org/10.1364/icusd.2012.iw2d.1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Gaft, M., L. Nagli, and Arnold Gucsik. "Time-Resolved Laser Based Spectroscopies for Mineralogical Research and Applications." In MICRO-RAMAN SPECTROSCOPY AND LUMINESCENCE STUDIES IN THE EARTH AND PLANETARY SCIENCES: Proceedings of the International Conference Spectroscopy 2009. AIP, 2009. http://dx.doi.org/10.1063/1.3222892.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Xie, X. Sunney, and Robert C. Dunn. "Near-field Time-Resolved Fluorescence Spectroscopy of Single Molecules." In Spectral Hole-Burning and Related Spectroscopies: Science and Applications. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/shbs.1994.fc2.

Full text
Abstract:
Fluorescence lifetime measurements on single dye molecules with nanometer spatial resolution are achieved by incorporating time-correlated single photon counting with a near-field fluorescence microscope.
APA, Harvard, Vancouver, ISO, and other styles
7

Wooseok, Heo, Kim JunWoo, Lee Changmin, and Joo Taiha. "Reaction dynamics by time-resolved wave packet spectroscopies & molecular dynamics simulation." In Asian Spectroscopy Conference 2020. Institute of Advanced Studies, Nanyang Technological University, 2020. http://dx.doi.org/10.32655/asc_8-10_dec2020.36.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Koichi, Iwata. "Properties of lipid bilayer membranes examined with time-resolved fluorescence and Raman spectroscopies." In Asian Spectroscopy Conference 2020. Institute of Advanced Studies, Nanyang Technological University, 2020. http://dx.doi.org/10.32655/asc_8-10_dec2020.1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Goldbeck, Robert A., and David S. Kliger. "Nanosecond time-resolved polarization spectroscopies and applications to the study of protein function and folding." In BiOS '98 International Biomedical Optics Symposium, edited by Joseph R. Lakowicz and J. B. Alexander Ross. SPIE, 1998. http://dx.doi.org/10.1117/12.307069.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Matousek, P., A. W. Parker, P. F. Taday, W. T. Toner, and M. Towrie. "Doubly Tunable Femtosecond Pulses Generated in the Visible using Optical Parametric Amplifiers for Time-resolved Spectroscopy." In Laser Applications to Chemical and Environmental Analysis. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/lacea.1996.lwd.3.

Full text
Abstract:
Many time-resolved spectroscopy techniques require two broadly and independently tunable, synchronised light pulses. This requirement can be met by optical parametric oscillators (OPOs) [1] and travelling wave optical parametric amplifiers (OPAs) [2, 3, 4, 5]. The latter capable of providing higher pulse energies. Our aim was to develop a multikilohertz repetition rate OPA system capable of providing femtosecond/picosecond, synchronised and independently tunable pump and probe pulses in the visible part of the spectrum for time-resolved absorption and resonance Raman spectroscopies.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Static and time resolved spectroscopies"

1

Sandstrom, Donald R. Study of Chemical Systems in Static and Time Resolved Mode by X-ray Absorption Spectroscopy. Fort Belvoir, VA: Defense Technical Information Center, November 1989. http://dx.doi.org/10.21236/ada215383.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Crawford, Daniel. "Structure and dynamics in complex chemical systems: Gaining new insights through recent advances in time-resolved spectroscopies.” ACS Division of Physical Chemistry Symposium presented at the Fall National ACS Meeting in Boston, MA, August 2015. Office of Scientific and Technical Information (OSTI), September 2016. http://dx.doi.org/10.2172/1326393.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Static and time resolved spectroscopies' for particular source types:
Journal articles Dissertations / Theses
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography