Download or read book Long lived Photophysics of Conjugated Polymers written by Christine Marie Liberatore Cuppoletti and published by . This book was released on 2002 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photophysics of Long lived Excitations in Pi conjugated Polymer Films and Devices written by Markus Wohlgenannt and published by . This book was released on 2000 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigating the Photochemistry and Photophysics of Conjugated Polymers by Single Molecule Spectroscopy written by Dehong Hu and published by . This book was released on 1999 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectral Properties and Photophysics of Conjugated Polymers in Electric Fields written by Timothy McCalvin Smith and published by . This book was released on 2006 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photophysics of Conjugated Polymers written by Tieneke E. Dykstra and published by . This book was released on 2008 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Poly (para-phenylenevinylene) (PPV), and its derivatives such as poly [2-methoxy, 5-(2'-ethyl-hexoxy)-1,4-phenylene vinylene] (MEH-PPV), are typical conjugated polymers. In order to implement conjugated polymers into processable electronics technologies, we must first understand their complex photophysical properties as their efficiencies depend on the balance between exciton recombination and charge carrier formation. The inherent complexities of these materials arise from entanglement of the pi-electron system with disorder and nuclear motions of the polymer backbone. This disorder breaks the polymer chain into conformational subunits which can couple, giving rise to a set of delocalized states formed by Coulombic interactions between proximate subunits. Characteristics of PPVs include high quantum yields, non-mirror image absorption and fluorescence line shapes, and large apparent Stokes' shifts. These properties are discussed in the context of the relationships between polymer conformation, electronic structure, coupling, disorder and polymer photophysics.These important influences are often manifest in the dynamics of what happens after photoexcitation. In this work, we present 3-pulse photon echo peak shift (3PEPS) studies of conjugated polymers in both solution and film. To elucidate timescales characteristic of relaxation processes, we have simulated the 3PEPS data simultaneously with absorption and fluorescence, observing a rapid localization of the exciton in the initial ∼ 20 fs. Additional contributions to the decay of the peakshift are discussed. We also present transient anisotropy data for PPV polymers and oligomers which is compared to dynamics simulation for isolated chains of PPVs. This work demonstrates the influence of microscopic structure on ultrafast dynamics. We show that relaxation between exciton states can lead to rapid depolarization of the anisotropy, even though the spatial extent of exciton migration may be small. Generally, the connection between conformation and electronic structure is a theme throughout this thesis.
Download or read book Photophysics of Conjugated Polymers and Oligomers written by Kurt Justin Baldwin and published by . This book was released on 1997 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Effective Particle Approach to the Photophysics of Conjugated Polymers written by Melissa Anna Pasquinelli and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photophysics of Conjugated Polymers written by Tieneke Emily Dykstra and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photophysics of Molecular Materials written by Guglielmo Lanzani and published by John Wiley & Sons. This book was released on 2006-05-12 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon based pi-conjugated materials offer a broad range of applications, going from molecular electronics and single molecule devices to nanotechnology, plastic electronics and optoelectronics. The proper physical description of such materials is in between that of molecular solids and that of low-dimensional covalent semiconductors. This book is a comprehensive review of their elementary excitations processes and dynamics, which merges the two viewpoints, sometimes very different if not contrasting. In each chapter, a broad tutorial introduction provides a solid physical background to the topic, which is further discussed based on recent experimental results obtained via state-of-the-art techniques. Both the molecular, intra-chain character and the solid state, inter-molecular physics is addressed. Reports on single molecule and single polymer chain spectroscopy introduce the on-site phenomena. Several chapters are dedicated to nano-probes, steady state and transient spectroscopies. The highly ordered state, occurring in single crystals, is also discussed thoroughly. Finally, less conventional tools such as THz spectroscopy are discussed in detail. The book provides a useful introduction to the field for newcomers, and a valid reference for experienced researchers in the field.
Download or read book Enhanced Photophysics of Conjugated Polymers written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The addition of oppositely charged surfactant to fluorescent ionic conjugated polymer forms a polymer-surfactant complex that exhibits at least one improved photophysical property. The conjugated polymer is a fluorescent ionic polymer that typically has at least one ionic side chain or moiety that interacts with the specific surfactant selected. The photophysical property improvements may include increased fluorescence quantum efficiency, wavelength-independent emission and absorption spectra, and more stable fluorescence decay kinetics. The complexation typically occurs in a solution of a polar solvent in which the polymer and surfactant are soluble, but it may also occur in a mixture of solvents. The solution is commonly prepared with a surfactant molecule:monomer repeat unit of polymer ratio ranging from about 1:100 to about 1:1. A polymer-surfactant complex precipitate is formed as the ratio approaches 1:1. This precipitate is recoverable and usable in many forms.
Download or read book Optical and Electronic Properties of Fullerenes and Fullerene Based Materials written by Joseph Shinar and published by CRC Press. This book was released on 1999-11-24 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text covers a host of fullerene applications, including nanotubes, compounds of fullerenes with other elements and structures and polymerized fullerenes. It discusses properties of photoexcited states of fullerenes, neutral and charged states, nonlinear optical response (NLO) and electron-electron interactions.
Download or read book The Influence of Interchain Interactions on the Photophysics of Conjugated Polymers written by and published by . This book was released on 2002 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photochemistry and Photophysics of Polymeric Materials written by Norman S. Allen and published by John Wiley & Sons. This book was released on 2010-03-18 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents the state of the technology, from fundamentals to new materials and applications Today's electronic devices, computers, solar cells, printing, imaging, copying, and recording technology, to name a few, all owe a debt to our growing understanding of the photophysics and photochemistry of polymeric materials. This book draws together, analyzes, and presents our current understanding of polymer photochemistry and photophysics. In addition to exploring materials, mechanisms, processes, and properties, the handbook also highlights the latest applications in the field and points to new developments on the horizon. Photochemistry and Photophysics of Polymer Materials is divided into seventeen chapters, including: Optical and luminescent properties and applications of metal complex-based polymers Photoinitiators for free radical polymerization reactions Photovoltaic polymer materials Photoimaging and lithographic processes in polymers Photostabilization of polymer materials Photodegradation processes in polymeric materials Each chapter, written by one or more leading experts and pioneers in the field, incorporates all the latest findings and developments as well as the authors' own personal insights and perspectives. References guide readers to the literature for further investigation of individual topics. Together, the contributions represent a series of major developments in the polymer world in which light and its energy have been put to valuable use. Not only does this reference capture our current state of knowledge, but it also provides the foundation for new research and the development of new materials and new applications.
Download or read book Film Stabilizaiton and Photophysics of Unconventional Conjugated Polymers written by Kara Martin and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Conjugated polymers offer a unique opportunity to develop high performing, flexible, lightweight, and large area electronic devices. With advances in conjugated polymer understanding and synthesis, the use of polymers as active layer materials in electronic applications, rather than just substrate materials, has become more promising. However, defects in morphological stability, as well as imperfect electronic understanding, are still present, limiting the use of these materials in commercializable electronics. Fundamental understanding of structure-property relationships can allow for facile synthetic solutions to major drawbacks of conjugated polymer integration in standard device architectures. Chapter 1 presents background research on the history of conjugated polymer development and the electronic device architectures these materials are typically incorporated in. Chapter 2 presents the use of thiol-ene chemistry to stabilize poly(3-alkylthiophene) films through a grafting-to procedure. This offers a simple way to produce highly oriented, insoluble, semi-conducting films through facile synthetic tuning of the polymers end-groups and side chains. In Chapter 3, the photophysics of carborane containing poly(dihexylfluorene) polymers is discussed. These unique class of materials experience drastic solvatochromism making them highly coveted for simple sensing applications. Through extensive spectroscopic investigations, a complete understanding of the excited-state dynamics is presented. Chapter 4 extends on Chapter 3 by demonstrating a straightforward method to synthesize carborane containing poly(dihexylfluorene)s with emissive properties that change with fluorene conjugation length, allowing for emission color tuning of the polymer solid and solution states. Lastly, Chapter 5 presents the synthesis of novel poly(bisthienyl carborane) and poly(bisthienyl carborane-alt-thiophene) is presented. This is the first example of a soluble conjugated polymer implementing a strong donor aromatic group and a strong acceptor carborane junction in the repeat unit. The fascinating excited-state characteristics are determined through femtosecond and nanosecond spectroscopy, showing the polymer can promote triplet formation on the carborane unit, making it useful for triplet sensitization applications. The work presented in this thesis shows that straightforward synthetic techniques can be used to highly affect the properties of common conjugated polymers, making them more robust or beneficial for electronic applications. Side-chain and backbone engineering is a necessary technique for furthering the development of useful and applicable "plastic" electronics.
Download or read book Understanding and Controlling Conjugated Polymer Conformation and Photophysics written by Youngah Kwon and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In general, this work suggests techniques and approaches to enhance understanding of various photophysical phenomena in conjugated polymers and other multichromophoric systems over an array of length scales.
Download or read book Photophysics and Photochemistry of Conjugated Polymer Nanoparticles written by Scott N. Clafton and published by . This book was released on 2014 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoparticles prepared by the reprecipitation of conjugated polymers are an exciting development in the field of biological imaging and fluorescence sensing. The colloidal stability of these hydrophobic polymers in aqueous suspension was found to originate from the surface charge density of ~15 mC/m2, which is in part attributed to negatively charged functional groups produced by polymer oxidation. The suitability of these nanoparticles in traditional conjugated polymer applications, such as polymer photovoltaics, was also investigated using femtosecond fluorescence upconversion and transient absorption spectroscopies. Polarisation resolved studies of energy transfer in highly compact nanoparticles and extended polymer conformations showed the nanoparticles exclusively undergo intermolecular energy transfer. These observations were supported by energy transfer simulations on polymer structures obtained from coarse-grained molecular dynamics simulations. Next, the recombination of polarons in composite rr-P3HT/PCBM nanoparticles, dominated by geminate recombination below 10 wt% PCBM, was demonstrated using a one dimensional diffusion model. This model also yielded the P3HT domain size of ~5 nm, which confirms these nanoparticles can serve as a model system for probing charge generation and recombination processes in device-like environments. Finally, the power dependent exciton decay in highly ordered nanowires yielded an exciton diffusion length of 11 ± 3 nm, which is toward the upper limit of diffusion lengths reported for annealed P3HT films. This data indicates the gentle solution based crystallisation of nanowires is a promising route for enhancing the performance of bulk heterojunction devices.
Download or read book An Investigation of the Photophysical Properties of Some Conjugated Polymers written by D. A. Ross and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
