Download or read book Understanding Morphology Evolution in Printed Organic Solar Cells written by Kevin Li Gu and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymer-based organic photovoltaics (OPVs) have emerged as a promising renewable energy candidate suitable for inexpensive and scalable production, being lightweight, flexible, and amenable to low-energy solution processing. However, despite having surpassed 10% power conversion efficiency (PCE) - widely held as the threshold for commercial viability - OPVs are still mostly constrained to lab-scale devices fabricated by spin coating. Efforts to translate to scalable roll-to-roll printing trail significantly in efficiency, commonly by an order of magnitude, highlighting the need to better understand the processing-morphology-performance relationship in the context of linear printing methods. The work presented will focus on two aspects of OPV development: 1) process control to translate from spin coating to printing in order to achieve scalable high-performance devices, and 2) application of improved tools for nanoscale morphological characterization. To the former, a thermodynamic model of phase separation is presented for a model polymer:fullerene system. Next we investigate a high-performance system which has demonstrated > 10% PCE via spincoating but only exhibits 1% PCE when roll-to-roll printed due to differences in drying dynamics and phase separation. OPV bulk heterojunctions are characterized using synchrotron X-ray scattering techniques, elucidating the impact of a critical residual chemical additive on the phase-separated morphology. It is discovered that excessive additive residence time within the semi-dry film gives rise to a hierarchal morphology that severely degrades device performance. Using the understanding gained in this study, we are able to achieve a printed OPV with 5.33% PCE, which is among the highest performing roll-to-roll OPVs to date. To the latter, we address the fact that commonly used microscopy techniques suffer from significant shortcomings for imaging OPVs. We demonstrate the first application of a technique known as Photo-induced Force Microscopy (PiFM) for imaging OPVs with nanoscale chemical specificity. Results from image processing are corroborated with established synchrotron methods and photovoltaic device performance, revealing excellent quantitative agreement. Further, we demonstrate that images from atomic force microscopy (AFM) and PiFM show poor correlation, highlighting the need to move beyond standard AFM for morphology characterization of bulk heterojunctions. We emphasize that PiFM is high-throughput, lab-scale, ambient, and requires no special sample preparation, filling an important underserved role in imaging of OPVs.

Download or read book Morphology Control Strategies to Enable Printable Solar Cells written by Sebastian Alexander Schneider and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Rapidly decarbonizing our way of life, parti¬cularly the way we generate power, will be critical to mitigate the potentially catastrophic effects of climate change. Time is of the essence and low-cost and scaleable energy technologies that are equitable can play a key role in these efforts. Organic photovoltaics (OPVs) are an emerging technology based on semiconducting organic polymers and molecules with many potential benefits, such as low weight, flexibility, and printability. In recent years, the performance of research level OPVs has significantly increased, closing the gap to established silicon solar cell technologies. Arguably, printability is one of the key advantages of OPVs, as it can facilitate high-throughput production at extremely low cost. Yet, producing high efficiency OPVs with scaleable production methods such as roll-to-roll (R2R) printing is a key challenge that remains on the path to commercialization and implementation of OPVs. This is largely due to the fact that the efficiency of OPVs strongly depends on the complex microstructure -- also referred to as morphology -- of the active layer that converts light into electricity. Controlling the self-assembly of the materials during printing is significantly more challenging on the industrial scale than on the lab scale. In this thesis, three morphology control strategies are developed that enable direct transfer to scaleable printing techniques while maintaining high solar cell efficiencies. The focus of this work is on developing structure-performance relationships using a suite of synchrotron X-ray scattering techniques for in-depth morphological characterizations. Further, we use these techniques to study the self-assembly of the active layer in real-time during printing and provide mechanistic insight on how different morphology control strategies can be leveraged to optimize the morphology and thereby the performance of printed OPVs. First, a high-level introduction outlines the challenge of rapid decarbonization and the role emerging solar cell technologies such as OPVs can play in addressing this challenge. Special emphasis is placed on the challenge of scaleability on the path to commercialization of OPVs. Chapter 2 provides relevant theoretical background on the three key areas relevant to this thesis research. (I) Organic solar cells, (II) X-ray characterization techniques for organic thin films, and (III) scaleable printing techniques for organic solar cells. Chapter 3 describes a systematic side-chain engineering molecular design approach to control the self-aggregation of a widely used OPV acceptor polymer enabling high performance printable all-polymer solar cells. We find that a balanced propensity of donor and acceptor to self-aggregate is key to achieve intrinsic printability for this material system. Specifically, we show a simple yet effective way to modulate the self-aggregation of the commonly used naphthalene diimide (NDI)-based acceptor polymer (N2200) by systematically replacing a certain amount of alkyl side-chains with compact bulky side-chains (CBS) resulting in a series of random copolymer (PNDI-CBSx) with different molar fractions. Both solution-phase aggregation and solid-state crystallinity of these acceptor polymers are increasingly suppressed with increasing molar fractions of the CBS side-chain. We find that balanced aggregation strength between the donor and acceptor polymers is critical to achieve high-performance (up to 8.5% efficient) all-PSCs with optimal active layer film morphology. Further, we show that balanced aggregation strength of donor and acceptor yields an active layer morphology that is less sensitive to the film deposition methods and solution coating can be achieved without performance losses. Chapter 4 showcases the systematic fluorination of a PBDB-TFy donor and PNDI-TFx acceptor polymer (x, y = 0, 50, 75, 100) and discusses the impact active layer morphology and device performance. We find that fluorination of donor and acceptor polymers does not significantly alter the crystallinity of the respective neat polymers but results in increased compatibility -- in terms of reduced Flory-Huggins interaction parameter -- of the materials. We observe a systematic increase of device performance with increased extent of fluorination. Morphological studies reveal that this improvement largely stems from a more favorable blend morphology with reduced domain size. Specifically, we characterize the domain size of the best performing blend PBDB-TF100:PNDI-TF100 in detail with RSoXS and HRTEM techniques. We observe good agreement between both techniques yielding a domain size close to 30 nm representing a significantly reduce phase separation compare to the non-fluorinated control system PBDB-TF0:PNDI-TF0. Further, we explore the device optimization of this system with the commonly used DIO additive in detail and find that DIO selectively interacts with the donor polymer leading to increased face-on texture crystallinity, further improving the fill factor of the solar cells. Chapter 5 provides in-depth mechanistic insight into the in-situ morphology evolution of all-polymers solar cell systems during scaleable printing. We demonstrate how non-covalent interactions between donor and acceptor polymers can be leveraged to achieve a morphology evolution that is insensitive to changes in the drying conditions and that translates exceptionally well to printing fabrication. Specifically, we systematically control the donor-acceptor interactions using different extents of fluorination of PDBD-TFy and PNDI-TFx (x, y = 0, 0.5, 1.0) donor and acceptor polymers. We show that donor-acceptor interactions can induce donor crystallization, facilitating a high solar cell fill factor (0.65) and excellent transferability to printing fabrication. Leveraging this molecular design strategy, we fabricate printed devices with up to 6.82 % efficiency (compared to the 3.61 % efficient control system). Chapter 6 showcases a novel solvent additive approach based on phthalate additives to control polymer crystallinity and suppress unfavorable phase separation in a representative PTB7-Th/P(NDI2OD-2T) all-polymer solar cell. The best-performing additive increased the blade-coated device performance from 2.09 to 4.50% power conversion efficiency, an over two-fold improvement, mitigating the loss in performance that is typically observed during process transfer from spin-coating to blade-coating. We find that the improved device performance stems from a finer polymer phase-separation size and overall improved active layer morphology. Real-time X-ray diffraction measurements during blade-coating provide mechanistic insights and suggest that the dioctyl phthalate additive may act as a compatibilizer, reducing the demixing of the donor and acceptor polymer during film formation, enabling a smaller phase separation and improved performance. Chapter 7 concludes this thesis with a summary of key conclusions and future directions of this work. Specifically, mixed phase characterization and morphology evolution of polymer:NFA systems, potential morphology control strategies for state-of-the-art all-polymer solar cells, and solvent quality and temperature aggregation studies are briefly discussed. Lastly, the appendix to this thesis provides an overview of selected examples of structural characterization of functional organic thin films to develop structure-property relations in organic solar cells and adjacent field such as organic field effect transistors (OFETs).

Download or read book Understanding Morphology and Photo stability of Organic Solar Cells Via Advanced Structural Probes written by Joseph Razzell Hollis and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Morphology Formation and Manipulation in Printed Organic Solar Cells written by Stephan Hubert Pröller and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Morphology Characterization and Understanding in Organic Solar Cells Based on Temperature Dependent Aggregation Property written by Guofang Yang and published by . This book was released on 2019 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Morphology Formation and Manipulation in Printed Organic Solar Cells written by Stephan Pröller 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 Understanding the Impact of Molecular Reorganization on Morphology Formation and Charge Transfer in Organic Solar Cells written by Stefan Wedler and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Morphology Characterization of Organic Solar Cell Materials and Blends written by John Daniel Roehling and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The organization of polymers and fullerenes, both in their pure states and mixed together, have a large impact on their macroscopic properties. For mixtures used in organic solar cells, the morphology of the mixture has a very large impact upon the mixture's ability to efficiently convert sunlight into useful electrical energy. Understanding how the morphology can change under certain processing conditions and in turn, affect the characteristics of the solar cell is therefore important to improving the function of organic solar cells.Conventional poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PCBM) solar cells have served as a staple system to study organic solar cell function for nearly a decade. Much of the understanding of how to make these "poorly" conductive organic materials efficiently convert sunlight into electricity has come from the study of P3HT:PCBM. It has long been understood that in order for a polymer:fullerene (electron donor and acceptor, respectively) mixture to function well as a solar cell, two major criteria for the morphology must be met; first, the interface between the two materials must be large to efficiently create charges, and secondly, there must be continous pathways through the "pure" materials for charges to be efficiently collected at the electrodes. This makes it advantageous for OPV materials to phase-separate into interconnected domains with very small domain sizes, a structure that P3HT:PCBM seems to naturally self-assemble. Despite P3HT:PCBM's ability to reach an optimal morphology, a complete understanding of exactly how the morphology affects device performance has not been realized. Completely different morphological models can end up predicting the same device performance characteristics. Much of the problem comes from the assumed morphology within a particular model, which can often be incorrect. The problem lies in the fact that obtaining real, accurate morphological information is difficult. An often neglected morphological feature is the existence of a third mixed phase, which is often unaccounted for because much about its composition and location are poorly understood. Obtaining this information and measuring the full morphology of OPV layers would therefore enable further understanding of device function. It is the aim of this thesis to demonstrate a technique which can measure the morphology of OPV layers accurately, accounting for the third phase and its composition. By using a scanning transmission electron microscope (STEM) in conjunction with electron tomography (ET) and an easily resolved fullerene component, the morphology of P3HT:fullerene layers are herein investigated. The combination of materials and techniques are demonstrated to accurately measure the morphology, illustrated by results which corroborate previous studies in the literature. It will be shown that not only can the position of each of the three phases present be measured, but their compositions can also be determined.Through this technique, morphologies formed under different processing conditions are quantitatively compared. The technique reveals differences between conventional processing methods that are not obvious through other measurements. Differences in the materials distribution throughout the thickness of the layer are also demonstrated and shown to give implications toward device function. Additionally, the precise changes in morphology which occur from different processing conditions are determined and shown to have a significant impact upon the properties of an OPV layer as a solar energy harvester. Not only does the morphology of the mixed materials affect the solar cell properties, but the local structure of the component materials themselves can strongly influence the macroscopic properties. By removing the fullerene component and forming pure domains of P3HT, the effects of internal structure on the properties of P3HT and how the structure is formed is also herein investigated.Through these techniques, the morphology and structure of different organic solar cell mixtures can now be thoroughly investigated. Through this work and future studies, the exact effects of morphology can be more fully understood. With the availability of accurate morphological data, it may now be possible to decouple morphology from other factors which govern device function.

Download or read book Solar Cell Materials written by Arthur Willoughby and published by John Wiley & Sons. This book was released on 2014-03-03 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comparison of solar cell materials, including both new materials based on organics, nanostructures and novel inorganics and developments in more traditional photovoltaic materials. It surveys the materials and materials trends in the field including third generation solar cells (multiple energy level cells, thermal approaches and the modification of the solar spectrum) with an eye firmly on low costs, energy efficiency and the use of abundant non-toxic materials.

Download or read book Novel Advances in Microsystems Technologies and Their Applications written by Laurent A. Francis and published by CRC Press. This book was released on 2017-07-28 with total page 637 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microsystems technologies have found their way into an impressive variety of applications, from mobile phones, computers, and displays to smart grids, electric cars, and space shuttles. This multidisciplinary field of research extends the current capabilities of standard integrated circuits in terms of materials and designs and complements them by creating innovative components and smaller systems that require lower power consumption and display better performance. Novel Advances in Microsystems Technologies and their Applications delves into the state of the art and the applications of microsystems and microelectronics-related technologies. Featuring contributions by academic and industrial researchers from around the world, this book: Examines organic and flexible electronics, from polymer solar cell to flexible interconnects for the co-integration of micro-electromechanical systems (MEMS) with complementary metal oxide semiconductors (CMOS) Discusses imaging and display technologies, including MEMS technology in reflective displays, the fabrication of thin-film transistors on glass substrates, and new techniques to display and quickly transmit high-quality images Explores sensor technologies for sensing electrical currents and temperature, monitoring structural health and critical industrial processes, and more Covers biomedical microsystems, including biosensors, point-of-care devices, neural stimulation and recording, and ultra-low-power biomedical systems Written for researchers, engineers, and graduate students in electrical and biomedical engineering, this book reviews groundbreaking technology, trends, and applications in microelectronics. Its coverage of the latest research serves as a source of inspiration for anyone interested in further developing microsystems technologies and creating new applications.

Download or read book On the Morphology of Polymer based Solar Cells to Achieve Higher Device Performance written by Yu Gu and published by . This book was released on 2014 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been recognized that the morphology of the active layer of the polymer-based solar cells has a great influence on the device performance. To push the efficiency to a higher level, morphology design and control by varying processing conditions are crucial. The theme of this dissertation is to characterize and understanding of the morphology of the active layer of polymer-based solar cells and the role that the morphology plays on device performance, so as to develop routes by which the morphology can be optimized. The focus of this dissertation is first on a binary system consisting of poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) (Chapter 2). Then composition of the active layer was extended to a more complicated ternary system containing poly(3-hexylthiophene) (P3HT), PCPDTBT and PCBM (from Chapter 3 to 5). Multiple characterization methods were used, including x-ray/neutron scattering or reflectivity techniques in combination with transmission electron microscopy and UV-vis absorption spectroscopy. Degree of ordering, degree of phase separation, molecular orientation and vertical component distribution were determined. Morphology evolution was monitored by conducting in-situ or ex-situ experiments and the driving force for generating the multi-length scale morphology was discussed. It was found that crystallization behaviors of conjugated polymers with or without confinement, with or without the use of processing additives were different. The interaction between polymers and PCBM had great influence on domain size and purity. The key factors for the success of polymer-based solar cells are high crystallinity, separated donor materials, bi-continuous donor and acceptor phases and large interfacial area.

Download or read book Examining and Controlling the Morphology of the Photoactive Layer of Organic Photovoltaic Devices written by Sameer Vajjala Kesava and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Electronic devices such as solar cells, transistors and light-emitting diodes (LEDs) fabricated using organic semiconductors offer a potential feasible alternative to their inorganic counterparts due to several advantages such as ease of processing (ink-jet printing, roll-to-roll processing), flexibility and excellent control over the electronic properties through chemical modifications. Compared to the inorganic semiconductors, however, the performance of organic semiconductor-based electronic devices are much lower. For example, in the case of photovoltaic devices (solar cells), the power-conversion efficiencies are still lower (7%-10%) compared to that of inorganic solar cells (> 25%). The efficiency of a solar cell is determined, among other factors, to a significant extent by the morphology of the active layer, the thin film where photons are absorbed and charges generated. Even though significant improvement in the efficiencies have been achieved, mainly through band-gap engineering and processing optimization, a fundamental understanding of the structural and morphological effects of the active layer on the performance of organic photovoltaic devices remains obscured. In this work, the focus is on examining the structure-function relationships in solution-processed bulk-heterojunction organic photovoltaic devices and development of processing techniques for device optimization. A bulk-heterojunction device is formed by mixing of donor-acceptor semiconductors, and the subsequent structure formed in the active layer is dictated by the miscibility and crystallization of the components, which are functions of processing conditions. Excitons (electron-hole pairs bound by coulombic forces) formed in the donor semiconductor upon absorption of light have a diffusion length of around 5-10 nm before recombination occurs. Thus the structural length scales formed in the active layer determine the number of excitons that can dissociate into charges. We have examined the microstructure of poly(3-hexyl thiophene) (P3HT) donor and phenyl-C61-butyric acid methyl ester (PC61BM) acceptor mixture using grazing incidence small angle X-ray scattering (GISAXS) and energy-filtered transmission electron microscopy (EFTEM) to characterize the in-plane structural length scales for various processing conditions such as annealing temperatures and spin-casting solvents. Our results show that the structural length scales are driven by self-limiting P3HT crystallization upon thermal annealing, which correlate to the internal quantum efficiencies of the devices. In contrast, it has been reported in the case of poly[2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene] (PBTTT)/ fullerene mixtures that thermal annealing results in crystallization of PBTTT with unconstrained lateral dimensions causing coarsening of the in-plane characteristic length scales. Thus the morphological evolution in polymer/fullerene solar cells, and consequently device performance, depends on the crystallization motif of the polymer. The microstructure resulting from mixing of donor-acceptor semiconductors can yield distinctive donor-acceptor interfaces that affect charge separation and recombination. Our studies utilizing a low band-gap poly[(4,4'-bis(2-ethylhexyl)dithieno[3,2-b:2',3'-d]germole)-2,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl] (PGeBTBT) donor and PC71BM acceptor examine the effects of mixing on the charge generation in a device. Composition of mixed phases ascertained qualitatively and quantitatively using EFTEM and resonance soft X-ray scattering (RSOXS) show that the concentration of polymer in the mixed phase decreases as fullerene concentration in the mixture is increased. This resulted in a concomitant increase in the device performance. Similarly, photo-induced absorption studies carried out using ultrafast spectroscopy show increase in polaron concentration with increase in purity of the mixed phase. Grazing-incidence wide-angle X-ray scattering (GIWAXS) data show a change in fullerene aggregation with increase in fullerene concentration in the mixture. This indicates that adding polymer to the mixed phase results in dispersal of fullerene, and consequently, changing the local environment of the polymer affects formation of charge-transfer states and subsequent dissociation into individual charges. Thus, high interfacial area that is formed upon intimate mixing of polymer/fullerene, considered ideal for efficient exciton dissociation, counteracts through high charge recombination. Our results show that the composition of mixed phases affects charge separation at the interface consequently affecting device performance of organic photovoltaics. Another important aspect that has been shown to affect device performance of organic photovoltaics is the orientation of polymer crystals with respect to the substrate. For example, P3HT predominantly orients in an edge-on configuration, i.e., with the [pi]-[pi] bond stacking direction parallel to the substrate. It is hypothesized that out of plane [pi]-[pi] stacking, called face-on orientation, is important for effective charge transport. One way to achieve enhancement of face-on orientation is by directional crystallization which has been shown to be very effective for P3HT -- in this case, directional crystallization from solution. In this context, 'zone-annealing' is relevant as it has been employed to directionally crystallize polymers. In this work, we designed and developed the zone-annealing equipment, which can yield thermal gradients greater than 60°C/mm. Preliminary results from GIWAXS experiments on P3HT/PC61BM thin films show anisotropy in the structure and a moderate enhancement of face-on orientated P3HT crystallites. This technique was extended to organic field-effect transistors (OFET) to enhance charge mobilities through directional crystallization of organic semiconductors. In case of P3HT, the increment in charge mobilities was by a factor of 2 upon zone-annealing. However, in the case of organic small molecule semiconductor, 2,7-dioctyl[1]benzo- thieno[3,2-b][1] benzothiophene (C8-BTBT) , highly aligned crystalline domains were obtained -- a very promising result for fabricating high mobility OFETs. Thus, the zone-annealing technique provides a handle for controlling the morphology of organic thin film electronic devices.

Download or read book Polymer Coatings written by Gijsbertus de With and published by John Wiley & Sons. This book was released on 2018-07-03 with total page 769 pages. Available in PDF, EPUB and Kindle. Book excerpt: A practical guide to polymer coatings that covers all aspects from materials to applications Polymer Coatings is a practical resource that offers an overview of the fundamentals to the synthesis, characterization, deposition methods, and recent developments of polymer coatings. The text includes information about the different polymers and polymer networks in use, resins for solvent- and water-based coatings, and a variety of additives. It presents deposition methods that encompass frequently used mechanical and electrochemical approaches, in addition to the physical-chemical aspects of the coating process. The author covers the available characterization methods including spectroscopic, morphological, thermal and mechanical techniques. The comprehensive text also reviews developments in selected technology areas such as electrically conductive, anti-fouling, and self-replenishing coatings. The author includes insight into the present status of the research field, describes systems currently under investigation, and draws our attention to yet to be explored systems. This important text: • Offers a thorough overview of polymer coatings and their applications • Covers different classes of materials, deposition methods, coating processes, and ways of characterization • Contains a text that is designed to be accessible and helps to apply the acquired knowledge immediately • Includes information on selected areas of research with imminent application potential for functional coatings Written for chemists in industry, materials scientists, polymer chemists, and physical chemists, Polymer Coatings offers a text that contains the information needed to gain an understanding of the charaterization and applications of polymer coatings.

Download or read book Evolution of Thin Film Morphology written by Matthew Pelliccione and published by Springer Science & Business Media. This book was released on 2008-01-29 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this book is on modeling and simulations used in research on the morphological evolution during film growth. The authors emphasize the detailed mathematical formulation of the problem. The book will enable readers themselves to set up a computational program to investigate specific topics of interest in thin film deposition. It will benefit those working in any discipline that requires an understanding of thin film growth processes.

Download or read book Conjugated Polymers written by John R. Reynolds and published by CRC Press. This book was released on 2019-03-25 with total page 853 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers properties, processing, and applications of conducting polymers. It discusses properties and characterization, including photophysics and transport. It then moves to processing and morphology of conducting polymers, covering such topics as printing, thermal processing, morphology evolution, conducting polymer composites, thin films

Download or read book Materials Science and Engineering written by S. Samudrala and published by Elsevier Inc. Chapters. This book was released on 2013-07-10 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials science research has witnessed an increasing use of data-mining techniques in establishing structure–process–property relationships. Significant advances in high-throughput experiments and computational capability have resulted in the generation of huge amounts of data. Various statistical methods are currently employed to reduce the noise, redundancy, and dimensionality of the data to make analysis more tractable. Popular methods for reduction (such as principal component analysis) assume a linear relationship between the input and output variables. Recent developments in nonlinear reduction (neural networks, self-organizing maps), though successful, have computational issues associated with convergence and scalability. This chapter reviews various spectral-based techniques that efficiently unravel linear and nonlinear structures in the data, which can subsequently be used to tractably investigate structure–property–process relationships. We compare and contrast the advantages and disadvantages of these techniques and discuss the mathematical and algorithmic underpinning of these methods. In addition, we describe techniques (based on graph-theoretic analysis) to estimate the optimal dimensionality of the low-dimensional parametric representation. We show how these techniques can be packaged into a modular, computationally scalable software framework with a graphical user interface – Scalable Extensible Toolkit for Dimensionality Reduction (SETDiR). This interface helps to separate out the mathematics and computational aspects from the material science applications, thus significantly enhancing utility to the materials science community. The applicability of the framework in constructing reduced order models of complicated materials data sets is illustrated.

Download or read book Handbook of Conducting Polymers Fourth Edition 2 Volume Set written by John R. Reynolds and published by CRC Press. This book was released on 2019-11-14 with total page 1488 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the last 10 years there have been major advances in fundamental understanding and applications and a vast portfolio of new polymer structures with unique and tailored properties was developed. Work moved from a chemical repeat unit structure to one more based on structural control, new polymerization methodologies, properties, processing, and applications. The 4th Edition takes this into account and will be completely rewritten and reorganized, focusing on spin coating, spray coating, blade/slot die coating, layer-by-layer assembly, and fiber spinning methods; property characterizations of redox, interfacial, electrical, and optical phenomena; and commercial applications.