Download or read book Chemical Control of Charge Trapping and Charge Transfer Processes at the Organic Inorganic Interface Within Quantum Dot Organic Complexes written by and published by . This book was released on 2015 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Within the research program funded through the Early Career Research Award we designed complexes of colloidal semiconductor quantum dots (QDs) and organic molecules in which the interfacial chemistry controls the electronic structure and dynamics of the excitonic state of the QD. The program included two main projects; (1) investigation of the mechanisms by which organic surfactants control the quantum confinement of excitonic charge carriers; and (2) development of models for electron transfer between QDs and adsorbed molecules as a function of interfacial chemistry. This project was extremely successful in that our achievements in those two areas addressed the great majority of questions we outlined in the original proposal and answered questions I did not think to ask in that original proposal. Our work led to the discovery of "exciton delocalizing ligands", which change the electronic structure of colloidal semiconductor nanocrystals by altering, with small synthetic modifications to their surfaces, their most defining characteristic - the quantum confinement of their excited states. It also led to detailed, quantitative descriptions of how the surface chemistry of a QD dictates, thermodynamically and kinetically, the probability of exchange of electrons between the QD and a small molecule. We used two of the three major techniques in the proposal (transient photoluminescence and transient absorption). Electrogenerated chemiluminescence was also proposed, but was too technically difficult with these systems to be useful. Instead, NMR spectroscopy emerged as a major analytical tool in our studies. With the fundamental advancements we made with this project, we believe that we can design QDs to be the next great class of visible-light photocatalysts.
Download or read book Semiconducting Polymers written by Christine Luscombe and published by Royal Society of Chemistry. This book was released on 2016-10-12 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconducting polymers are of great interest for applications in electroluminescent devices, solar cells, batteries and diodes. In recent years vast advances have been made in the area of controlled synthesis of semiconducting polymers, specifically polythiophenes. The book is separated into two main sections, the first will introduce the advances made in polymer synthesis, and the second will focus on the microstructure and property analysis that has been enabled because of the recent advances in synthetic strategies. Edited by one of the leaders in the area of polythiophene synthesis, this new book will bring the field up to date with more recent models for understanding semiconducting polymers. The book will be applicable to materials and polymers chemists in industry and academia from postgraduate level upwards.
Download or read book Intramolecular Charge Transfer written by Ramprasad Misra and published by John Wiley & Sons. This book was released on 2018-02-27 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bridging the gap between the multitude of advanced research articles and the knowledge newcomers to the field are looking for, this is a timely and comprehensive monograph covering the interdisciplinary topic of intramolecular charge transfer (ICT). The book not only covers the fundamentals and physico-chemical background of the ICT process, but also places a special emphasis on the latest experimental and theoretical studies that have been undertaken to understand this process and discusses key technological applications. After outlining the discovery of ICT molecules, the authors go on to discuss several important substance classes. They present the latest techniques for studying the underlying processes and show the interplay between charge transfer and the surrounding medium. Examples taken from nonlinear optics, viscosity and polarity sensors, and organic electronics testify to the vast range of applications. The result is a unique information source for experimentalists as well as theoreticians, from postgraduate students to researchers.
Download or read book Organic Charge transfer Complexes written by Roy Foster and published by . This book was released on 1969 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Charge Transfer in Physics Chemistry and Biology written by A.M. Kuznetrsov and published by CRC Press. This book was released on 2020-09-23 with total page 637 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the various processes of charge transfer in physics, chemistry and biology and shows the similarities and differences between them. It focuses on the physical mechanisms of the elementary processes to demonstrate their common physical nature.
Download or read book Spectroscopic Investigation of Ground State Charge Transfer in Organic Mixed valence and Charge transfer Systems written by Angela Bischof and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Electron transfer processes are widespread in chemistry, and form the basis of photosynthetic systems and molecular electronic devices. However, studying electron transfer processes in these systems directly can be difficult. In order to understand the fundamental processes in these systems, charge transfer (CT) and mixed-valence (MV) compounds have been used extensively as model systems to study the basics of electron transfer reactions under various conditions. This dissertation uses steady-state spectroscopic analyses to determine how structure affects electronic coupling and charge delocalization in several MV and CT systems that are of interest for understanding the fundamental processes that occur in organic devices. In Chapter 2, we find that the introduction of an ethylene bridging ligand between two bis(alkoxy)benzene redox sites increases the intramolecular electronic coupling when compared to the system in which the redox active sites are directly connected, despite an increase in distance. We quantify the increase in coupling as a function of both distance and steric effects. Chapter 3 focuses on the systematic investigation of how van der Waals forces control the electronic coupling in non-covalently bound organic mixed-valence naphthalene diimide dimers, and we find that, in general, as the van der Waals forces in the intermolecular complex increase so does the electronic coupling. Chapter 4 focuses on the analysis of the CT band in donor-acceptor charge-transfer liquid crystals (DACLCs) and uses resonance Raman spectroscopy to investigate the phase-dependence of the charge transfer transition and the vibrational modes that are associated with this transition. Overall, this dissertation contributes to the fundamental understanding of how structure impacts charge transfer in organic MV and CT systems.
Download or read book Charge Transfer Processes Across Organic written by Hsiao-Chu Lin and published by . This book was released on 2013 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: Charge transfer efficiency at organic/electrode interfaces affects the performance organic photovoltaics (OPVs). It is hypothesized that the charge collection efficiency at organic/electrode interfaces is influenced by the structure of the first molecular layer adjacent to the electrode surface. Two differently oriented monolayers composed of two phosphonic acid (PA) functionalized zinc phthalocyanine (ZnPc) molecules, one with four PAs attached peripherally (ZnPcPA4), one at each quadrant, and another that is functionalized with one PA (ZnPcPA), were tethered to indium tin oxide (ITO) surfaces as models for the donor/transparent conducting oxide (TCO) interface in OPVs to address the relationship between molecular orientation and electron transfer kinetics across the organic/ITO interface. The electron transfer rate constants across the monolayer/ITO interface were measured using potential modulated attenuated total reflectance (PM-ATR) spectroscopy in TE and TM polarizations, which allows rate constants to be determined for subpopulations of molecules that are oriented predominately in-plane and out-of-plane, respectively. The templating effect of the tethered monolayer on sequential layers of donor material for ZnPcPA and ZnPcPA4 monolayers was assessed by depositing a few layers of CuPc on ZnPcPA- and ZnPcPA4-modified ITO. The performance of OPV devices fabricated on ITO modified with these two monolayers was compared and correlated to their orientation and energy alignments with other layers in the devices. The dependence of kinetics of electron transfer on overpotential was studied using monolayer-tethered ZnPcPA on ITO. Measurements of apparent heterogeneous electron transfer rate constants (kapp) as a function of applied potential across the ZnPcPA/ITO interface were acquired using PM-ATR at various dc biases (Edc). With varying Edc imposed on the electrode, the fraction of adsorbed molecules in reduced or oxidized states is changed, and both the energetics and kinetics of the electrode reaction are affected. The results were discussed and compared to theoretical predictions. The photoinduced charge harvesting and photocurrent generation were assessed using a clicked ZnPc-perylene diimide (PDI) donor-acceptor assembly tethered to ITO via a PA anchoring group. This ZnPc-PDI donor-acceptor assembly was used to investigate the mechanism of photoinduced charge transfer and hole-capture by ITO in the presence of a solution phase redox mediator.
Download or read book Colloidal Quantum Dot Optoelectronics and Photovoltaics written by Gerasimos Konstantatos and published by Cambridge University Press. This book was released on 2013-11-07 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: Captures the most up-to-date research in the field, written in an accessible style by the world's leading experts.
Download or read book Charge Transfer Complexes in Biological Systems written by Felix Gutmann and published by CRC Press. This book was released on 1997-05-20 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Examining the role played by partial charge transfer in biology, this work offers a theroetical basis of the physics and chemistry of charge transfer complex formation, especially the function of excited states. It discusses drug interactions, highlighting interaction between different types of antibiotics and suggests ways for the synthesis of pharmaceutical products with reduced side effects.
Download or read book Charge Injection Charge Trapping and Charge Transfer in Quantum dot Solids written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ternary Quantum Dots written by Oluwatobi Samuel Oluwafemi and published by Woodhead Publishing. This book was released on 2021-07-02 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ternary Quantum Dots: Synthesis, Properties, and Applications reviews the latest advances in ternary (I-III-VI) chalcopyrite quantum dots (QDs), along with their synthesis, properties and applications. Sections address the fundamental key concepts of ternary quantum dots, progress in synthesis strategies (i.e., organic and aqueous synthesis), and characterization methods (i.e., transmission electron microscopy, dynamic light scattering, etc.). Properties of ternary quantum dots are comprehensively reviewed, including optical, chemical and physical properties. The factors and mechanisms of the cytotoxicity of ternary quantum dot-based nanomaterials are also described. Since ternary chalcopyrite quantum dots are less toxic and more environmentally benign than conventional binary II-VI chalcogenide quantum dots, they are being investigated to replace conventional quantum dots in a range of applications. Thus, this book reviews QDs in various applications, such as solar cells, photocatalytic, sensors and bio-applications. Reviews fundamental concepts of ternary quantum dots and quantum dot-nanocomposites including the most relevant synthesis strategies, key properties, and characterization techniques Delves into the cytotoxicity of quantum dots looking at the factors and mechanisms that influence cytotoxicity including demonstration of cytotoxicity assays for in vitro and in vivo tests Touches on the many applications of ternary quantum dots including biomedical applications, applications in solar cells, sensing applications, and photocatalytic applications
Download or read book Hybrid Inorganic organic Organic Charge Transfer and Radical Based Compounds with Chalcofulvalene Donors and Organic Acceptors written by Eric Wade Reinheimer and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary focus of this dissertation is the electrochemical preparation of radical cation salts utilizing the donor o-4,40́9-dimethyltetrathiafulvalene (o-Me2TTF) and spherical, tetrahedral, octahedral, bimetallic, cyanometallate, and polyoxometallate anions. Other donors, such as tetramethyl(tetraselenafulvalene) (TMTSF), tetramethyl(tetrathiafulvalene) (TMTTF), bis(ethylenedithio)tetrathiafulvalene (BEDTTTF or ET), and bis(propylenedithio)tetrathiafulvalene (BPDT-TTF or PT) also found use in the preparation of salts in the course of this study. X-ray structural characterization of these salts revealed stacking between donor molecules containing significant S0́Ø0́Ø0́ØS interactions in the solid state. Various salts were subjected to either conductivity or molecular magnetism measurements in order to determine the level of itinerant electron density and magnetic contribution from paramagnetic charge compensating anions. In order to expand the library of TTF-containing hybrid materials prepared through metathesis, salts of other tetrathiafulvalenium radicals have also been prepared and characterized crystallographically and by select spectroscopic methods. In an effort to gain further information on formation of organic charge transfer complexes, TTF was combined with nitrofluorenone family of acceptors as well as the organocyanide acceptors HAT-(CN)6 (HAT-(CN)6 = 1,4,5,8,9,12-hexaazatriphenylenehexacarbonitrile) and TCNB (TCNB = 1,2,4,5-tetracyanobenzene). The complexes were characterized using X-ray crystallography, infrared spectroscopy, and molecular magnetism. All of these techniques showed that all compounds underwent little to no charge transfer. Commencing in 2003, the combined work of Dunbar and Omary revealed that systems combining inorganic donors with chelating, sulfur-based ligands and organic acceptors could have their spectroscopic response tuned to display low-energy charge transfer bands extending into the near-IR making them suitable candidates as photosensitizing dyes for semiconductors. In keeping with this idea, new layered charge transfer compounds combining the nitrofluorenone family of acceptors and the inorganic donor Pt(dbbpy)(tdt) (tdt = 3,4-toluenedithiolate) were prepared. The resulting complexes were characterized utilizing X-ray crystallography as well as both spectroscopic and electrochemical methods. Similar analyses were also conducted on various platinum/terpyridine salts and illustrated a level of spectroscopic tunability to that observed for the supramolcular systems composed of inorganic donors and organic acceptors.
Download or read book Intramolecular Charge Transfer in Solvated Organic Molecules written by Mercedes V. Bohnwagner and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Halide Perovskites written by Tze-Chien Sum and published by John Wiley & Sons. This book was released on 2019-03-25 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real insight from leading experts in the field into the causes of the unique photovoltaic performance of perovskite solar cells, describing the fundamentals of perovskite materials and device architectures. The authors cover materials research and development, device fabrication and engineering methodologies, as well as current knowledge extending beyond perovskite photovoltaics, such as the novel spin physics and multiferroic properties of this family of materials. Aimed at a better and clearer understanding of the latest developments in the hybrid perovskite field, this is a must-have for material scientists, chemists, physicists and engineers entering or already working in this booming field.
Download or read book Handbook of Materials Modeling written by Sidney Yip and published by Springer Science & Business Media. This book was released on 2007-11-17 with total page 2903 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first reference of its kind in the rapidly emerging field of computational approachs to materials research, this is a compendium of perspective-providing and topical articles written to inform students and non-specialists of the current status and capabilities of modelling and simulation. From the standpoint of methodology, the development follows a multiscale approach with emphasis on electronic-structure, atomistic, and mesoscale methods, as well as mathematical analysis and rate processes. Basic models are treated across traditional disciplines, not only in the discussion of methods but also in chapters on crystal defects, microstructure, fluids, polymers and soft matter. Written by authors who are actively participating in the current development, this collection of 150 articles has the breadth and depth to be a major contributor toward defining the field of computational materials. In addition, there are 40 commentaries by highly respected researchers, presenting various views that should interest the future generations of the community. Subject Editors: Martin Bazant, MIT; Bruce Boghosian, Tufts University; Richard Catlow, Royal Institution; Long-Qing Chen, Pennsylvania State University; William Curtin, Brown University; Tomas Diaz de la Rubia, Lawrence Livermore National Laboratory; Nicolas Hadjiconstantinou, MIT; Mark F. Horstemeyer, Mississippi State University; Efthimios Kaxiras, Harvard University; L. Mahadevan, Harvard University; Dimitrios Maroudas, University of Massachusetts; Nicola Marzari, MIT; Horia Metiu, University of California Santa Barbara; Gregory C. Rutledge, MIT; David J. Srolovitz, Princeton University; Bernhardt L. Trout, MIT; Dieter Wolf, Argonne National Laboratory.
Download or read book Charge Transfer Photochemistry of Coordination Compounds written by Otto Horvath and published by Wiley-VCH. This book was released on 1993 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure function Relationships in Organic Charge transfer Complexes written by Katelyn Patricia Goetz and published by . This book was released on 2016 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
