Transition Of Frequency Domain Coherent Multidimensional Spectroscopic Methods To The Femtosecond Time Regime With Applications To Nanoscale Semiconductors

Author : Schuyler Kain
Publisher :
ISBN 13 :
Total Pages : 598 pages
Book Rating : 4.78/5 ( download)

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Download or read book Transition of Frequency-domain Coherent Multidimensional Spectroscopic Methods to the Femtosecond Time Regime with Applications to Nanoscale Semiconductors written by Schuyler Kain and published by . This book was released on 2017 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: The author describes in this dissertation his work to conduct a wide range of frequency-domain coherent multi-color multidimensional experiments in the femtosecond time regime. A software platform, COLORS, was developed in the LabVIEW environment to calibrate and control tunable light sources, motorized optical delay stages, spectrometers, and data acquisition cards. To take advantage of the hardware control, automated routines were composed to conduct linear and multidimensional frequency, delay, and Wigner experiments. The software was designed with three principles in mind: minimalism, modularity, and extensibility. The author demonstrates the use of COLORS to conduct state-of-the-art multidimensional experiments on two nanomaterial systems--colloidal PbSe quantum dots and a few-layer thin-film of MoS2. In the PbSe studies, three-photon echo peak shift (3PEPS) and transient-grating experiments observed rapid ∼70-fs relaxation dynamics occurring within the 1S excitonic lineshape. These dynamics suggested the presence of fine structure that was inconsistent with the Particle-in-a-Sphere model of electronic structure under quantum confinement. The homogeneous and inhomogeneous contributions to the 1S excitonic linewidth were found to be ∼450 and ∼600 cm-1, respectively. Transient-grating studies performed in reflective geometry on a few-layer thin-film of MoS2 revealed the rapid appearance after excitation of a spectral cross-peak between the A and B excitons. If excitation was at or above the B excitonic feature, strong cross-peaks were created from hot A and B excitons as they underwent ultrafast intraband population transfer. Excitation below the B excitonic feature created a weak cross-peak, indicating an A-induced bleach of the B transition. Population relaxation occurred over ∼680 fs, either by transfer to traps or by bimolecular charge recombination.

Author : Minhaeng Cho
Publisher : Springer
ISBN 13 : 9811397538
Total Pages : 404 pages
Book Rating : 4.30/5 ( download)

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Download or read book Coherent Multidimensional Spectroscopy written by Minhaeng Cho and published by Springer. This book was released on 2019-08-06 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book will fulfill the needs of time-domain spectroscopists who wish to deepen their understanding of both the theoretical and experimental features of this cutting-edge spectroscopy technique. Coherent Multidimensional Spectroscopy (CMDS) is a state-of-the-art technique with applications in a variety of subjects like chemistry, molecular physics, biochemistry, biophysics, and material science. Due to dramatic advancements of ultrafast laser technologies, diverse multidimensional spectroscopic methods utilizing combinations of THz, IR, visible, UV, and X-ray radiation sources have been developed and used to study real time dynamics of small molecules in solutions, proteins and nucleic acids in condensed phases and membranes, single and multiple excitons in functional materials like semiconductors, quantum dots, and solar cells, photo-excited states in light-harvesting complexes, ions in battery electrolytes, electronic and conformational changes in charge or proton transfer systems, and excess electrons and protons in water and biological systems.

Author : Blaise Jonathan Thompson
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.14/5 ( download)

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Download or read book Development of Frequency Domain Multidimensional Spectroscopy with Applications in Semiconductor Photophysics written by Blaise Jonathan Thompson and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Coherent multidimensional spectroscopy (CMDS) encompasses a family of experimental strategies involving the nonlinear interaction between electric fields and a material under investigation. This approach has several unique capabilities: (1) resolving congested states, (2) extracting spectra that would otherwise be selection-rule disallowed, (3) resolving fully coherent dynamics, (4) measuring coupling, and (5) resolving ultrafast dynamics. CMDS can be collected in the frequency or the time domain, and each approach has advantages and disadvantages. Frequency domain ``Multi-resonant'' CMDS (MR-CMDS) requires pulsed ultrafast light sources with tunable output frequencies. These pulses are directed into a material under investigation. The pulses interact with the material, and due to the specific interference between the multiple fields the material is driven to emit a new pulse: the MR-CMDS signal. This signal may have a different frequency and/or direction than the input pulses, depending on the exact experiment being performed. The MR-CMDS experiment involves tracking the intensity of this output signal as a function of different properties of the excitation pulses. These properties include (1) frequency. (2) relative arrival time and separation (delay), (3) fluence, and (4) polarization, among others. Thus MR-CMDS can be thought of as a multidimensional experimental space, where experiments typically involve explorations in one to four of the properties above. Because MR-CMDS is a family of related-but-separate experiments, each of them a multidimensional space, there are special challenges that must be addressed when designing a general-purpose MR-CMDS instrument. These issues require development of software, hardware, and theory. Part I: Background introduces relevant literature which informs on this development work. Part II: Development presents five strategies used to improve MR-CMDS: (1) processing software, (2) acquisition software (3), active artifact correction, (4) automated OPA calibration, and (5) finite pulse accountancy. Finally, Part III: Applications presents four examples where these instruments, with these improvements, have been used to address chemical questions in semiconductor systems.

Author : William Ray Jeffries
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.62/5 ( download)

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Download or read book Coherent Multidimensional Spectroscopy as a Probe for Femtosecond Relaxation Dynamics of Metal Colloids written by William Ray Jeffries and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electronic carrier dynamics are integral in the design of functional metal transducers. Moreover, the optical properties and dynamics of colloidal metals depend sensitively their structures. Hence, a comprehensive understanding of how structural factors like size, geometry, and composition influence electronic relaxation processes allows for the development of predictive models for judicious selection of nanoscale metals for photonic applications. This dissertation focused on the usage of time-resolved nonlinear spectroscopy techniques, specifically femtosecond transient absorption and two-dimensional electronic spectroscopy (2DES) to probe electronic relaxation dynamics in colloidal metals, including: monolayer-protected clusters (MPCs), plasmonic gold nanorods, metal hybrid nanostructures, and 2-D semiconductors. The ultrafast relaxation mechanisms in all of these systems were understood in relation to structure-specific and state-resolved dynamics. 2DES results resolved excited-state symmetry-dependent relaxation dynamics in 38-atom gold nanoclusters that were influenced by specific metal kernel and inorganic semiring structures. It is shown that Fermi liquid dynamics can be resolved in plasmonic metal ensembles. It is also shown that synthetic modification to size and composition of a single domain in composite metal nanostructures can be used to overcome bulk-like contributions that govern phonon-mediated thermalization. In addition, phonon-mediated renormalization rates across different materials thicknesses (i.e. number layers) in 2-D semiconductors is described. All of these results indicate that specific nanostructures (size, composition, thickness, and geometry) play integral roles in governing ultrafast relaxation dynamics in complex nanoscale metal colloids, which in turn can be leveraged to develop predictive models for optimal design of functional metal transducers.

Author :
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.13/5 ( download)

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Download or read book Picosecond and Femtosecond Coherent Multidimensional Spectroscopy of Colloidal PbSe Quantum Dot Structure and Dynamics written by and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiresonant coherent multidimensional spectroscopy (MR-CMDS) is a fully coherent mixed frequency/time domain technique that selectively characterizes vibrational and electronic energetic structure and dynamics. The work reported here describes technique development with 1-picosecond pulses on model vibrational systems, application of this technique to PbSe quantum dots, and recent adaptation to include use of 50-femtosecond pulses. An overview of the quantum mechanical theory behind experimental design and interpretation, with an emphasis on the perturbative limit, is included. A record of the instrumentation and optical component selection associated with both laser systems is provided, which is particularly important for the development of the femtosecond laser table. Initial experiments on the femtosecond system revealed environmental artifacts that have now been identified and characterized. Picosecond pulses are not a good match for studying PbSe quantum dots with MR-CMDS because the pulses are too long to isolate coherence lifetimes and fully coherent processes. Frequency domain results previously acquired on the picosecond system revealed coherence lifetimes near 50fs, which directed the selection of a more appropriate laser system. Experiments with femtosecond pulses are now confirmed to directly measure coherence lifetimes and selectively emphasize spectral signatures from fully coherent processes that were not visible with longer pulses. These confirmations reveal that the flexibility of MR-CMDS techniques, as developed on the model vibrational systems, is available for quantum-confined semiconductor structures. Future directions include laser system improvements and suggestions of samples that may better inform dye-sensitized solar cell core charge transfer events.

Author : Nathan Allen Mathew
Publisher :
ISBN 13 :
Total Pages : 473 pages
Book Rating : 4.04/5 ( download)

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Download or read book Mixed Frequency/time Domain Coherent Multidimensional Spectroscopy written by Nathan Allen Mathew and published by . This book was released on 2010 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : Ernst Lippert
Publisher : Springer Science & Business Media
ISBN 13 : 3642794076
Total Pages : 598 pages
Book Rating : 4.70/5 ( download)

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Download or read book Dynamics During Spectroscopic Transitions written by Ernst Lippert and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: "How does a photon get into an atom?" This question - fundamental to quantum mechanics - puzzled leading scientists such as Schrödinger and Heisenberg and is still asked by students. James D. Macomber's book was the first to provide a didactic and unified approach to the answer, which has now been updated by way of recent experimental results and modern theoretical interpretations written by leading scientists. It provides an understanding for similarities among the spectroscopic methods available and is stimulating to read, reflecting the excitement of scientific research.

Author : Hélène Seiler
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.27/5 ( download)

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Download or read book Development of Coherent Two-dimensional Spectroscopy at Optical Frequencies and Application to Model Chromophores written by Hélène Seiler and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Ultrafast coherent multi-dimensional spectroscopies are a powerful set of techniques used to unravel complex processes. These processes range from electronic coherences in molecular chromophores to many-body interactions in quantum-confined materials. Yet these spectroscopies remain challenging to implement at the high frequencies of vibrational and electronic transitions, thereby limiting their widespread use. The work herein demonstrates three significant methodological improvements of two-dimensional spectroscopy at optical frequencies, followed by applications of the method on two different systems. First, we introduce a hollow-fibre setup for the production of broadband visible pulses. This source is comparatively simple to operate, and yields stable, 45 [mu]J pulses over the 520-700 nm region. Second, we demonstrate the feasibility of two-dimensional electronic spectroscopy in a single beam. By appropriately modulating the phases of the pulses within the beam,we show that it is possible to directly read out the relevant optical signals. This work shows that one needs neither complex beam geometries nor complex detection schemes in order to measure 2D spectra at optical frequencies. Finally, we introducea setup for complete and independent polarization control of each pulse in the sequence. Together, these methodological improvements represent important enabling steps towards the longstanding goal of achieving an "Optical NMR", and extendsthe realm of all-optical multi-dimensional spectroscopies to spatially heterogeneous samples. The methods are applied on two classes of systems. The model system Nile Blue is used to validate the performance of the instrument. The spectrometeris then used to reveal new processes in colloidal semiconductor CdSe nanocrystals, a system of contemporary interest." --

Author : Ernst Lippert
Publisher : Springer
ISBN 13 : 9783540587033
Total Pages : 580 pages
Book Rating : 4.39/5 ( download)

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Download or read book Dynamics During Spectroscopic Transitions written by Ernst Lippert and published by Springer. This book was released on 1995-05-16 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: "How does a photon get into an atom?" This question - fundamental to quantum mechanics - puzzled leading scientists such as Schrödinger and Heisenberg and is still asked by students. James D. Macomber's book was the first to provide a didactic and unified approach to the answer, which has now been updated by way of recent experimental results and modern theoretical interpretations written by leading scientists. It provides an understanding for similarities among the spectroscopic methods available and is stimulating to read, reflecting the excitement of scientific research.

Author : Connor Devyn William Mosley
Publisher : Springer
ISBN 13 : 9783030669010
Total Pages : 115 pages
Book Rating : 4.17/5 ( download)

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Download or read book Enhanced Polarisation Control and Extreme Electric Fields written by Connor Devyn William Mosley and published by Springer. This book was released on 2021-03-26 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis reports advances in terahertz time-domain spectroscopy, relating to the development of new techniques and components that enhance the experimentalist’s control over the terahertz polarisation state produced by photoconductive emitters. It describes how utilising the dynamic magnetoelectric response at THz frequencies, in the form of electromagnons, can probe material properties at a transition between two magnetically ordered phases. Additionally, preliminary investigations into the properties of materials exposed to extreme terahertz optical electric fields are reported. The work presented in this thesis may have immediate impacts on the study of anisotropic media at THz frequencies, with photoconductive emitters and detectors being the most commonly used components for commercially available terahertz spectroscopy and imaging systems, and by providing a new way to study the nature of magnetic phase transitions in multiferroics. In the longer term the increased understanding of multiferroics yielded by ultrafast spectroscopic methods, including terahertz time-domain spectroscopy, may help develop new magnetoelectric and multiferroic materials for applications such as spintronics.