Download or read book Eco friendly Halogen free Solvent Processed Efficient Polymer Solar Cell Fabrication and Morphology Engineering written by Guler Kocak and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing energy demand and diminishing non-renewable energy resources have resulted in facing our biggest challenges for the last decades, and these are indications for more alarming problems such as global warming and pollution. The motivation for this research is based on the state-of-the-art actions to take in order to solve these problems and propose that eco-friendly organic photovoltaics can play a vital role. -- The most abundant and clean energy is solar, and it needs to be utilized with cost-effective and eco-friendlier techniques in the future. Existing solar panels that are commonly used are fabricated in a costlier manner and they require materials that can negatively impact the environment. Whereas, organic photovoltaics (OPV) offer both lightweight architecture and eco-friendliness, and their efficiencies are approaching to 20% with ongoing research which are exceptionally promising. -- Yet, the most important challenges for OPVs are their large-scale applicability and environmental effect for future industrial production. In order to fabricate large-scale and also flexible devices, it is preferrable to be able to experiment with materials that are processable in air without using toxic chemicals in a cost-effective way. -- Therefore, this thesis focuses on both optimization of photo-active layers of OPVs with non-halogenated processing solvents and fabrication of these eco-friendlier solar cells via slot-die coating printing technique. The donor-acceptor (D-A) groups of organic materials are selected initially to be evaluated in inverted devices and different post-treatments were methodically analysed. The successful solvent systems that gave the best performing devices for polymer-fullerene and polymer-non fullerene D-A pairs were specifically tested and characterized for their applicability in printed devices. -- In Chapter 3, a highly popular donor polymer PTB7-Th and non-fullerene acceptor (NFA) ITIC pair was tested in devices made using eco-friendly solvent systems with spin-coating process. The existing solvent systems and fabrication ways for the formation of the organic thin film layer for the same polymer and fullerene systems were also used for comparison. The best performing device efficiency with NFA system was found to be greater than that of reported in the literature and our experiments gave a PCE of 8.5% even when we use our eco-friendly fabrication method. -- Also, techniques for efficient and proper removal of toxic solvent additives for the same D-A pairs were investigated. In order to support this research besides the device performances, surface and thermal characterizations were further carried out. -- In Chapter 4, the motivation was solely on the eco-friendly fabrication and optimization of photo-active layers of solar cells. High performing devices using less harmful solvent systems were found for PTNT polymer and fullerene materials, and they are tested later in Chapter 5 for their applicability for printing techniques. -- In Chapter 5, materials that were extensively studied in previous chapters were also evaluated for flexible device fabrication with eco-friendly methods and post-treatments such as PTNT polymer and fullerene acceptors. PTNT polymer gave high efficiencies (~5%) with this flexible device processing using green solvents, and supported our proposal of new fabrication techniques and use of non-halogenated solvent systems in many more OSC materials commonly tested in literature. The device photovoltaic properties and the microscopy images of the thin film layers were always reported to complement each other and supported our arguments when different treatments were applied. The morphology controllability using pre-and post- treatments of active layers were investigated in detail, especially in Chapter 3 and 5. -- In summary, the inverted polymer solar cells were fabricated with novel green and cost-effective techniques and examined for other comparable polymer-acceptor systems for the best efficiency and eco-friendliness. They were also tested in flexible cell architecture appropriateness and proved their importance for future use in large-scale green solar cell applications with good efficiencies.
Download or read book Processing and Optical Engineering of Polymer fullerene Solar Cells Towards High Efficiency and Environmentally Friendly Fabrication for Real life Applications written by Kung-Shih Chen and published by . This book was released on 2014 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Facing the tremendous challenges of energy shortage and global warming, embracing renewable energies is an obvious choice and necessary action. Solar energy is arguably the most important source of renewable energy. Organic photovoltaics (OPV) has the potential to make the solar energy much more affordable. However, OPV technology is still relatively new and immature and requires substantial improvements on device performance, stability, fabrication, and many other aspects to make OPV actually useful. The studies described in this dissertation are aimed to address some of the critical challenges and provide ideas for future developments. In chapters 1 and 2 the motivations and current developments of OPV research are briefly overviewed. In chapter 3, two high performance polymer:fullerene bulk-heterojunction solar cells used in the works of this dissertation are described. Chapter 4 describes our developments of a device processing approach that involves completely halogen-free solvents, which is desirable to achieve sustainable large-scale fabrication of OPV cells. The solvent system, consisting of small amount of a novel solvent additive 1-methylnaphthalene (Me-naph) in common halogen-free solvent matrix, can drastically improve phase-separated morphology of OPV devices to achieve efficient charge separation and yield high-performance. In Chapter 5, OPV devices in a novel optical resonant cavity structure are systematically investigated. Such structure has exhibited several advantages: first, light trapping of thin film OPV devices can be boosted by carefully tuning the optical field in the resonant cavity. Second, replacing the typical transparent ITO electrode with semi-transparent TeO2/Ag electrode simultaneously solves or ameliorates multiple problems associated with the ITO electrode such as high cost, brittleness, and limited conductance, making the cavity structure viable for making flexible and large-area device. In Chapter 6, semi-transparent organic photovoltaic (OPV) cells with high device performance and tunable transparency are demonstrated. The devices not only possess high performance to transparency ratio but also close to perfect color rendering index (nearly 100), making it a strong candidate for power-generating window applications.
Download or read book Polymer Photovoltaics written by Fei Huang and published by Royal Society of Chemistry. This book was released on 2016 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: An international perspective on the latest research in polymer solar cell technology.
Download or read book Printable Solar Cells written by Nurdan Demirci Sankir and published by John Wiley & Sons. This book was released on 2017-04-25 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: Printable Solar Cells The book brings together the recent advances, new and cutting edge materials from solution process and manufacturing techniques that are the key to making photovoltaic devices more efficient and inexpensive. Printable Solar Cells provides an overall view of the new and highly promising materials and thin film deposition techniques for printable solar cell applications. The book is organized in four parts. Organic and inorganic hybrid materials and solar cell manufacturing techniques are covered in Part I. Part II is devoted to organic materials and processing technologies like spray coating. This part also demonstrates the key features of the interface engineering for the printable organic solar cells. The main focus of Part III is the perovskite solar cells, which is a new and promising family of the photovoltaic applications. Finally, inorganic materials and solution based thin film formation methods using these materials for printable solar cell application is discussed in Part IV. Audience The book will be of interest to a multidisciplinary group of fields, in industry and academia, including physics, chemistry, materials science, biochemical engineering, optoelectronic information, photovoltaic and renewable energy engineering, electrical engineering, mechanical and manufacturing engineering.
Download or read book Properties of Polymers written by D.W. van Krevelen and published by Elsevier. This book was released on 2012-12-02 with total page 898 pages. Available in PDF, EPUB and Kindle. Book excerpt: Properties of Polymers: Their Correlation with Chemical Structure; Their Numerical Estimation and Prediction from Additive Group Contributions summarizes the latest developments regarding polymers, their properties in relation to chemical structure, and methods for estimating and predicting numerical properties from chemical structure. In particular, it examines polymer electrical properties, magnetic properties, and mechanical properties, as well as their crystallization and environmental behavior and failure. The rheological properties of polymer melts and polymer solutions are also considered. Organized into seven parts encompassing 27 chapters, this book begins with an overview of polymer science and engineering, including the typology of polymers and their properties. It then turns to a discussion of thermophysical properties, from transition temperatures to volumetric and calorimetric properties, along with the cohesive aspects and conformation statistics. It also introduces the reader to the behavior of polymers in electromagnetic and mechanical fields of force. The book covers the quantities that influence the transport of heat, momentum, and matter, particularly heat conductivity, viscosity, and diffusivity; properties that control the chemical stability and breakdown of polymers; and polymer properties as an integral concept, with emphasis on processing and product properties. Readers will find tables that give valuable (numerical) data on polymers and include a survey of the group contributions (increments) of almost every additive function considered. This book is a valuable resource for anyone working on practical problems in the field of polymers, including organic chemists, chemical engineers, polymer processers, polymer technologists, and both graduate and PhD students.
Download or read book Optimizing Morphology of Bulk Heterojunction Polymer Solar Cells written by Jing Gao and published by . This book was released on 2014 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of bulk heterojunction polymer solar cells is profoundly influenced by the spatial arrangements of microstructure at various length scales in its photo-active layer, referred to as morphology. Due to their complex chemical structures, polymers usually exhibits low crystallinity and carrier mobility, leading to a limited thickness ~100 nm of the active layer for a typical polymer solar cell. Such thin films are incompatible with the prevailing large-area coating techniques, thus increasing the difficulty to realize the high-throughput production of polymer-based photovoltaics in industry. On the other hand, for most high-performance low-band-gap polymers, during their film-casting process, processing solvent additives are usually essential for morphology optimization, which help boost device efficiency. However, most commonly-used solvent additives such as 1, 8-Diiodooctane (DIO), are disturbingly reactive to oxygen or water in air, leading to deteriorated performance of devices made under the ambient environment. Therefore, fabrication processes involving DIO have to be limited to an air-free environment, which is quite unfavorable for large-area fabrication techniques, as majority of them are carried on under the ambient environment. Therefore, an efficient air-stable solvent additive would be greatly appreciated in terms of OPV industrialization. As a result, in order to achieve thick active layers as well as to find an air-stable alternative additive for industrial applications, a thorough and systematic study on morphology is necessitated. First, via rational modification of polymer chemical structure(fine-tuning on side chains), new polymers with enhanced structure order (e.g., crystallite size increases from 35 Å to 53 Å) and higher hole mobility (from ~10-5 to ~10-4 cm2/(V*s)) are obtained, enabling thicker optimum active layers ~200 nm with a larger thickness tolerance up to ~350 nm for the corresponding bulk heterojunction devices. This result is of great potential for relaxing the required level of precision in active layer thickness, which has important industrial implications for large-area film deposition. Second, through examining those solvents with a great potential to satisfy the criteria for efficient additives, a new efficient air-stable solvent additive -1,2-dichlorobenzene (DCB) was successfully found for the Diketopyrrolopyrrole-based narrow bandgap polymer under investigation in this work, with a much larger working operation window (up to 80%) and higher device efficiency than DIO. The reason for improved performance lies in higher hole mobility due to polymer crystallinity enhancement in films cast from solution processed by both additives, as demonstrated by Transmission Electron Microscopy (TEM), photoluminescence (PL) and Grazing Incident Wide Angle X-ray Scattering (GIWAXS) results. Small Angle Neutron Scattering (SANS) and UV-visible absorption spectroscopy were also conducted on polymer structures in solution, and their results revealed a novel working mechanism of DCB for morphology control, which involves the modified solution-stage polymer conformations due to the polymer-additive interaction. Upon incorporating DCB into blend solution, the resultant polymer configurations in solution would have a high tendency to preserve into crystalline regions in the as-cast films and this unique way of tuning thin-film morphology via altering polymer conformations in solution has established a new guide for future additive selection in other polymer systems. Results of this manuscript will resolve the current obstacle for high-throughput process in industry and should be of great potential to contribute to practical OPV applications in the near future.
Download or read book Polymer Solar Cells written by Vishal Shrotriya and published by . This book was released on 2010-03 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Morphology Evolution in High performance Polymer Solar Cells Processed from Nonhalogenated Solvent written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A new processing protocol based on non-halogenated solvent and additive is developed to produce polymer solar cells with power conversion efficiencies better than those processed from commonly used halogenated solvent-additive pair. Morphology studies show that good performance correlates with a finely distributed nanomorphology with a well-defined polymer fibril network structure, which leads to balanced charge transport in device operation.
Download or read book High Performance Multi Component Organic Solar Cells written by Ismail Alperen Ayhan and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Renewable energies significantly gained in importance in the last decade. Due to worldwide ecological problems and global warming, much effort is needed to increase the awareness and protect earth from the impacts with respect to the climate changes. Particularly, the excessive use of fossil fuels force countries to figure out some alternative applications for the energy supply. Other than hydro and wind-based applications, solar energy becomes the most important renewable technology to reduce the carbon dioxide emission and worldwide photovoltaic systems have recently been installed by gradually rising. Since only China and India are building several coal powers every week for energy needs based-on their population1, it is very important to develop efficient and low-cost solar energy systems to attract attention for especially newly develop countries other than develop ones. Organic solar cells (OSCs) are one of the most promising solar energy systems due to some unique advantages, such as low-cost, lightweight, flexible, semitransparent, large area compatibility, easy fabrication (roll to roll), easy processing (from solution), and energy level tunability, which enables new fields of applications. In contrast to inorganic solar cells, high temperature fabrication techniques are not needed to prepare organic photovoltaics. In solution processed OSCs, the organic semiconductor materials are used in active layer to absorb light and convert it to electrical energy. The active layers containing donor and accepter components where the optimized morphology is achieved through an interpenetrating phase-separated donor-acceptor network that is called as bulk heterojunction. The efficiency of bulk heterojunction OSCs is strongly correlated with the morphology of their active layers, which requires an optimized distribution of the donor and acceptor domains. A large interface between donor and acceptor domains are needed to obtain efficient exciton dissociation at interface. Also, percolation pathways are required to transport the charges to the corresponding electrodes. The nanomorphology depends on tendency of the active layer components to crystallization and phase-separation. These morphological properties can be optimized by altering the process parameters, such as selection of materials and solvents, composition, thickness, and thermal treatments. Recently, OSCs has been remarkably enhanced with power conversion efficiency exceeding 16% by virtue of new materials development and device optimizations.2--4 It is commonly known that the limited absorption window of organic semiconductors causes low photon-harvesting ability from active layer. Multi-component organic solar cells, which consist of one donor and two acceptors, are a promising strategy for broadening the light absorption spectrum and enhancing the power conversion efficiency (PCE) of the organic photovoltaic devices, due to the diverse small molecular materials with different optical band gaps and good compatibility. In this dissertation, the binary and ternary blend systems were studied through optimizing processing parameters and the effect of these parameters on the structural, morphological, electrical and photovoltaic properties were investigated by performing UV-vis absorption, EQE measurement, Grazing-Incidence Wide-Angle X-ray Scattering (GIWAXS) and energy-filtered transmission electron microscopy (EFTEM). In the first part of dissertation, it is found that optimized blends share a universal fibril-like structure, where the polymer donor appears to dictate fibril size. In the second part of section, the effect of third component in ternary blend OSCs is discussed where the optimum morphology is achieved and if the ternary blend systems also have similar morphology such as fibril-like structure. As expected, the ternary blend system showed significant enhancement of device performance due to broadening of the absorption spectrum and the fill factor. We attribute that the high morphology compatibility of the ternary system can benefit to optimized electron/hole mobility and diminished recombination.
Download or read book Sefer efer qoda im written by אפריים ברמן and published by . This book was released on 1971 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Perovskite Photovoltaics written by Aparna Thankappan and published by Academic Press. This book was released on 2018-06-29 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perovskite Photovoltaics: Basic to Advanced Concepts and Implementation examines the emergence of perovskite photovoltaics, associated challenges and opportunities, and how to achieve broader development. Consolidating developments in perovskite photovoltaics, including recent progress solar cells, this text also highlights advances and the research necessary for sustaining energy. Addressing different photovoltaics fields with tailored content for what makes perovskite solar cells suitable, and including commercialization examples of large-scale perovskite solar technology. The book also contains a detailed analysis of the implementation and economic viability of perovskite solar cells, highlighting what photovoltaic devices need to be generated by low cost, non-toxic, earth abundant materials using environmentally scalable processes. This book is a valuable resource engineers, scientists and researchers, and all those who wish to broaden their knowledge on flexible perovskite solar cells. - Includes contributions by leading solar cell academics, industrialists, researchers and institutions across the globe - Addresses different photovoltaics fields with tailored content for what makes perovskite solar cells different - Provides commercialization examples of large-scale perovskite solar technology, giving users detailed analysis on the implementation, technical challenges and economic viability of perovskite solar cells
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 Organic Optoelectronic Materials written by Yongfang Li and published by Springer. This book was released on 2015-05-30 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reviews the latest trends in organic optoelectronic materials. Each comprehensive chapter allows graduate students and newcomers to the field to grasp the basics, whilst also ensuring that they have the most up-to-date overview of the latest research. Topics include: organic conductors and semiconductors; conducting polymers and conjugated polymer semiconductors, as well as their applications in organic field-effect-transistors; organic light-emitting diodes; and organic photovoltaics and transparent conducting electrodes. The molecular structures, synthesis methods, physicochemical and optoelectronic properties of the organic optoelectronic materials are also introduced and described in detail. The authors also elucidate the structures and working mechanisms of organic optoelectronic devices and outline fundamental scientific problems and future research directions. This volume is invaluable to all those interested in organic optoelectronic materials.
Download or read book Polymer Solar Cells written by Lilian Chang and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic solar cells have the potential to be unrivaled in terms of processing cost, speed, and simplicity. The simplest of such devices consists of a single bulk-heterojunction (BHJ) active layer, in which the electron donor (conjugated polymer) and electron acceptor (fullerene) are deposited from a common solvent. The performance of BHJ solar cells is strongly correlated with the nanoscale structure of the active layer. Various processing techniques have been explored to improve the nanoscale morphology of the BHJ layer, e.g. by varying the casting solvent, thermal annealing, solvent annealing, and solvent additives. An understanding of the role of residual solvent in the BHJ layer is imperative in order to develop strategies for morphology stabilization and preserve the longevity of the device. This work highlights the effect of residual solvents on acceptor, (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) diffusion and ultimately the stability of the morphology. We first show that solvent is retained within the BHJ film despite prolonged heat treatment, leading to extensive phase separation between poly(3-hexylthiophene) (P3HT) and PCBM. We then show that the addition of a small volume fraction of nitrobenzene to the casting solution inhibits the diffusion of PCBM in the film and improves the fill factor of the BHJ device without further tempering. Other commonly used additives for morphology improvement were also investigated, i.e. 1,8-diiodooctane and 1-chloronaphthalene. We show that the choice of solvent additives has direct implications on morphological evolution, i.e. P3HT:PCBM BHJ films processed with a small amount of 1,8-diiodooctane or 1-chloronaphthalene have more crystalline PCBM domains compared to crystalline P3HT domains, while the opposite is true for films cast with nitrobenzene additive and films cast purely from chlorobenzene. The BHJ film cross-links when annealed at 300°C in the presence of 1,8-diiodooctane. Cross-linking is found to occur even in pristine P3HT and PCBM films annealed under similar conditions.Our work in understanding solvent interactions greatly facilitated our venture into multi-junction solution-processed devices. In our exploration of various device architectures for optimal performance, we have also established a way to modify the surface energy of a film to render it amenable to subsequent solution-processing. The tandem architecture offers a strategy to efficiently harvest photons from the full solar spectrum by stacking multiple photoactive layers with complementary absorption spectra. We found that the current predominant choices for solution-processed electron transport layer (ETL) each have their problems when implemented into a tandem device. Hence, we are presenting the novel use of stacked perovskite, (TBA,H)Ca2Nb3O10 (CNO), semiconductor nanosheets as an ETL and we have successfully demonstrated a completely solution-processed tandem polymer solar cell. While further optimization of the CNO-layer is still required, the robust CNO-layer can be spin-coated on top of the BHJ photoactive layer and is stable towards subsequent processing and heat-treatment. We also explored the feasibility of introducing silver nanoparticles into the device structure via a low-cost solution-processable route for the exploitation of surface plasmon resonance for near-field absorption enhancement in the photoactive layer. We find that the photo-reduction of Ag+ to Ag appears to be a promising route for in-situ deposition of Ag nanoparticles.
Download or read book Fundamentals of Solar Cell Design written by Inamuddin and published by John Wiley & Sons. This book was released on 2021-08-24 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar cells are semiconductor devices that convert light photons into electricity in photovoltaic energy conversion and can help to overcome the global energy crisis. Solar cells have many applications including remote area power systems, earth-orbiting satellites, wristwatches, water pumping, photodetectors and remote radiotelephones. Solar cell technology is economically feasible for commercial-scale power generation. While commercial solar cells exhibit good performance and stability, still researchers are looking at many ways to improve the performance and cost of solar cells via modulating the fundamental properties of semiconductors. Solar cell technology is the key to a clean energy future. Solar cells directly harvest energy from the sun’s light radiation into electricity are in an ever-growing demand for future global energy production. Solar cell-based energy harvesting has attracted worldwide attention for their notable features, such as cheap renewable technology, scalable, lightweight, flexibility, versatility, no greenhouse gas emission, environment, and economy friendly and operational costs are quite low compared to other forms of power generation. Thus, solar cell technology is at the forefront of renewable energy technologies which are used in telecommunications, power plants, small devices to satellites. Aiming at large-scale implementation can be manipulated by various types used in solar cell design and exploration of new materials towards improving performance and reducing cost. Therefore, in-depth knowledge about solar cell design is fundamental for those who wish to apply this knowledge and understanding in industries and academics. This book provides a comprehensive overview on solar cells and explores the history to evolution and present scenarios of solar cell design, classification, properties, various semiconductor materials, thin films, wafer-scale, transparent solar cells, and so on. It also includes solar cells’ characterization analytical tools, theoretical modeling, practices to enhance conversion efficiencies, applications and patents.
Download or read book Perovskite Photovoltaics and Optoelectronics written by Tsutomu Miyasaka and published by John Wiley & Sons. This book was released on 2022-03-21 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perovskite Photovoltaics and Optoelectronics Discover a one-of-a-kind treatment of perovskite photovoltaics In less than a decade, the photovoltaics of organic-inorganic halide perovskite materials has surpassed the efficiency of semiconductor compounds like CdTe and CIGS in solar cells. In Perovskite Photovoltaics and Optoelectronics: From Fundamentals to Advanced Applications, distinguished engineer Dr. Tsutomu Miyasaka delivers a comprehensive exploration of foundational and advanced topics regarding halide perovskites. It summarizes the latest information and discussion in the field, from fundamental theory and materials to critical device applications. With contributions by top scientists working in the perovskite community, the accomplished editor has compiled a resource of central importance for researchers working on perovskite related materials and devices. This edited volume includes coverage of new materials and their commercial and market potential in areas like perovskite solar cells, perovskite light-emitting diodes (LEDs), and perovskite-based photodetectors. It also includes: A thorough introduction to halide perovskite materials, their synthesis, and dimension control Comprehensive explorations of the photovoltaics of halide perovskites and their historical background Practical discussions of solid-state photophysics and carrier transfer mechanisms in halide perovskite semiconductors In-depth examinations of multi-cation anion-based high efficiency perovskite solar cells Perfect for materials scientists, crystallization physicists, surface chemists, and solid-state physicists, Perovskite Photovoltaics and Optoelectronics: From Fundamentals to Advanced Applications is also an indispensable resource for solid state chemists and device/electronics engineers.
Download or read book Photoenergy and Thin Film Materials written by Xiao-Yu Yang and published by John Wiley & Sons. This book was released on 2019-03-19 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the latest research & developments and future trends in photoenergy and thin film materials—two important areas that have the potential to spearhead the future of the industry. Photoenergy materials are expected to be a next generation class of materials to provide secure, safe, sustainable and affordable energy. Photoenergy devices are known to convert the sunlight into electricity. These types of devices are simple in design with a major advantage as they are stand-alone systems able to provide megawatts of power. They have been applied as a power source for solar home systems, remote buildings, water pumping, megawatt scale power plants, satellites, communications, and space vehicles. With such a list of enormous applications, the demand for photoenergy devices is growing every year. On the other hand, thin films coating, which can be defined as the barriers of surface science, the fields of materials science and applied physics are progressing as a unified discipline of scientific industry. A thin film can be termed as a very fine, or thin layer of material coated on a particular surface, that can be in the range of a nanometer in thickness to several micrometers in size. Thin films are applied in numerous areas ranging from protection purposes to electronic semiconductor devices. The 16 chapters in this volume, all written by subject matter experts, demonstrate the claim that both photoenergy and thin film materials have the potential to be the future of industry.
