Download or read book High Performance Organic Photovoltaics Via Novel Materials Combinations written by and published by . This book was released on 2011 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: OPV cell efficiencies have increased significantly over the last decade and verified champion efficiencies are currently at 8.3% for both single and multi-junction device types. These increases in efficiency have been driven through the development and optimization of the donor and acceptor materials in bulk heterojunction active layers. Plextronics and Solarmer Energy Inc. are two of the world leading developers of these donor and acceptor materials. Solarmer Energy has reported NREL certified 6.77% efficiencies using optimized low band gap donor materials in combination with PC61BM and PC71BM acceptors and recently reported a champion NREL certified efficiency of 8.1%. Plextronics has reported Newport certified efficiencies of 6.7% using PC71BM acceptors with low band gap materials. In addition, Plextronics has also demonstrated that OPV efficiency of P3HT based materials can be improved by 50% by improving the Voc using alternative acceptors (indene substituted C60 and C70) to PC61BM and PC71BM. However, performance of these alternative acceptors in combination with low band gap materials has not been investigated and the potential for efficiency improvement is evident. In this collaboration, four low band gap donor materials from Solarmer Energy Inc were combined with Plextronics' indene-class acceptors Plextronics' indene substituted C60 and C70 acceptors to demonstrate OPV performance greater than 7%. Two main indene class C60 acceptors (codenamed Mono-indene[C60] Mono-indene[C60], Bis-indene[C60]) were screened with the Solarmer polymers. These four polymers were screened and optimized with the indene class acceptors at both Plextronics and Solarmer. A combination was identified which produced 6.7% (internal measurement) with a Solarmer polymer and a Plextronics fullerene acceptor. This was accomplished primarily by improving the Voc as well as improving the current (Jsc) and FF.

Download or read book Achieving High Performance Polymer Tandem Solar Cells Via Novel Materials Design written by Letian Dou and published by . This book was released on 2014 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic photovoltaic (OPV) devices show great promise in low-cost, flexible, lightweight, and large-area energy-generation applications. Nonetheless, most of the materials designed today always suffer from the inherent disadvantage of not having a broad absorption range, and relatively low mobility, which limit the utilization of the full solar spectrum. Tandem solar cells provide an effective way to harvest a broader spectrum of solar radiation by combining two or more solar cells with different absorption bands. However, for polymer solar cells, the performance of tandem devices lags behind single-layer solar cells mainly due to the lack of suitable low-bandgap polymers (near-IR absorbing polymers). In this dissertation, in order to achieve high performance, we focus on design and synthesis of novel low bandgap polymers specifically for tandem solar cells. In Chapter 3, I demonstrate highly efficient single junction and tandem polymer solar cells featuring a spectrally matched low-bandgap conjugated polymer (PBDTT-DPP: bandgap, ~1.44 eV). The polymer has a backbone based on alternating benzodithiophene and diketopyrrolopyrrole units. A single-layer device based on the polymer provides a power conversion efficiency of ~6%. When the polymer is applied to tandem solar cells, a power conversion efficiency of 8.62% is achieved, which was the highest certified efficiency for a polymer solar cell. To further improve this material system, in Chapter 4, I show that the reduction of the bandgap and the enhancement of the charge transport properties of the low bandgap polymer PBDTT-DPP can be accomplished simultaneously by substituting the sulfur atoms on the DPP unit with selenium atoms. The newly designed polymer PBDTT-SeDPP (Eg = 1.38 eV) shows excellent photovoltaic performance in single junction devices with PCEs over 7% and photo-response up to 900 nm. Tandem polymer solar cells based on PBDTT-SeDPP are also demonstrated with a 9.5% PCE, which are more than 10% enhancement over those based on PBDTT-DPP. Finally, in Chapter 5, I demonstrate a new polymer system based on alternating dithienopyran and benzothiadiazole units with a bandgap of 1.38 eV, high mobility, deep highest occupied molecular orbital. As a result, a single-junction device shows high external quantum efficiency of>60% and spectral response that extends to 900 nm, with a power conversion efficiency of 7.9%. The polymer enables a solution processed tandem solar cell with certified 10.6% power conversion efficiency under standard reporting conditions, which is the first certified polymer solar cell efficiency over 10%.

Download or read book Organic Solar Cells written by Wallace C.H. Choy and published by Springer Science & Business Media. This book was released on 2012-11-19 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic solar cells have emerged as new promising photovoltaic devices due to their potential applications in large area, printable and flexible solar panels. Organic Solar Cells: Materials and Device Physics offers an updated review on the topics covering the synthesis, properties and applications of new materials for various critical roles in devices from electrodes, interface and carrier transport materials, to the active layer composed of donors and acceptors. Addressing the important device physics issues of carrier and exciton dynamics and interface stability and novel light trapping structures, the potential for hybrid organic solar cells to provide high efficiency solar cells is examined and discussed in detail. Specific chapters covers key areas including: Latest research and designs for highly effective polymer donors/acceptors and interface materials Synthesis and application of highly transparent and conductive graphene Exciton and charge dynamics for in-depth understanding of the mechanism underlying organic solar cells. New potentials and emerging functionalities of plasmonic effects in OSCs Interface Degradation Mechanisms in organic photovoltaics improving the entire device lifetime Device architecture and operation mechanism of organic/ inorganic hybrid solar cells for next generation of high performance photovoltaics This reference can be practically and theoretically applied by senior undergraduates, postgraduates, engineers, scientists, researchers, and project managers with some fundamental knowledge in organic and inorganic semiconductor materials or devices.

Download or read book Polymer polymer blends in organic photovoltaic and photodiode devices written by Yuxin Xia and published by Linköping University Electronic Press. This book was released on 2019-01-04 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic photovoltaics devices (OPV) have attracted attentions of scientist for their potential as inexpensive, lightweight, flexible and suitable for roll-to-roll production. In recent years, considerable attention has been focused on new acceptor materials, either polymeric or small molecules, to replace the once dominating fullerene derivatives. The emergence of numerous new non-fullerene materials has driven power conversion efficiency (PCE) up to 17%, attracting more and more interests of commercialization. Polymer acceptors with more morphology stability, more absorption and more desired energy levels has been intensively studied and show great potential for large area and low-cost production in the future. OPV at this moment is not yet competitive with inorganic solar cells in PCE but is more attractive in flexibility, low weight and semitransparency. In this thesis, some basic knowledges of OPV is introduced in the first few chapters, while the next chapters are focusing on polymer-polymer blends and investigating novel structures and techniques for large scale production of solar cells and photodetectors aiming at maximizing these advantages to compete with inorganic counterpart. Thermal annealing effects on polymer-polymer solar cells based is studied. Annealed devices show doubled power conversion efficiency compared to non-annealed devices. Based on the morphology—mobility examination, we conclude that the better charge transport is achieved by higher order and better interconnected networks of the bulk heterojunction in the annealed active layers. The annealing improves charge transport and extends the conjugation length of the polymers, which do help charge generation and meanwhile reduce recombination. The blend of an amorphous polymer and a semi-crystalline polymer can thus be modified by thermal annealing to double the power conversion efficiency. A novel concept of all-polymer organic photovoltaics device is demonstrated in this thesis where all the layers are made out of polymers. We use PEDOT:PSS as semitransparent anode and polyethyleneimine modified PEDOT:PSS as semitransparent cathode, both of which are slot-die printed on polyethylene terephthalate(PET). Active layers are deposited on cathode and anode surfaces by spin coating separately. These layers are then joined through a roll-to-roll compatible lamination process. This forms a semitransparent and flexible solar cell. By laminating a thin layer acceptor polymer to a thick polymer-polymer blend, we can further improve the performance by reducing traps comparing to laminating blend to blend. Flexible and semitransparent all-polymer photodiodes with different geometries can be fabricated through lamination. By choosing high band gap polymers and appropriate combination of two or more polymers, organic photodiode with low noise and high specific detectivity can be obtained. Comparison between bilayer and bulk heterojunction devices gives better understanding of the origin of noise and provides ways to improve the performance of photodiodes as detector. Noise level is a critical parameter for photodetectors. The difficulties of measuring the noise of photodetectors make some researchers prefer the estimated shot noise as the dominating one and ignore the thermal noise and 1/f noise. The latter two terms are sometimes several orders higher than the former, noting the importance of experimentally measuring noise. The use of semi-transparent photovoltaic devices causes an inevitable loss of photocurrent, as light transmitted has not been absorbed. This trivial effect also leads to a loss of photovoltage, an effect partially due to the lower photocurrent but also due to the geometry of the semitransparent photovoltaic device. We here demonstrate and evaluate this photovoltage loss in semi-transparent organic photovoltaic devices, compared with non-transparent solar cells of the same material. Semi-transparent solar cells in addition introduce photovoltage loss when formed by lamination. We document and analyze these effects for a number of polymer blends in the form of bulk heterojunctions.

Download or read book Photovoltaics Beyond Silicon written by Senthilarasu Sundaram and published by Elsevier. This book was released on 2024-07-01 with total page 819 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photovoltaics Beyond Silicon: Innovative Materials, Sustainable Processing Technologies, and Novel Device Structures presents the latest innovations in materials, processing and devices to produce electricity via advanced, sustainable photovoltaics technologies. The book provides an overview of the novel materials and device architectures that have been developed to optimize energy conversion efficiencies and minimize environmental impacts. Advances in technologies for harnessing solar energy are extensively discussed, with topics including materials processing, device fabrication, sustainability of materials and manufacturing, and the current state-of-the-art. Contributions from leading international experts discuss the applications, challenges and future prospects of research in this increasingly vital field, providing a valuable resource for students and researchers working in this area. - Presents a comprehensive overview and detailed discussion of solar energy technology options for sustainable energy conversion - Provides an understanding of the environmental challenges to be overcome and discusses the importance of efficient materials utilization for clean energy - Looks at how to design materials processing and optimize device fabrication, including metrics such as power-to-weight ratio, effectiveness at EOL compared to BOL, life-cycle analysis

Download or read book Organic Photovoltaics written by Sam-Shajing Sun and published by CRC Press. This book was released on 2017-12-19 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently developed organic photovoltaics (OPVs) show distinct advantages over their inorganic counterparts due to their lighter weight, flexible shape, versatile materials synthesis and device fabrication schemes, and low cost in large-scale industrial production. Although many books currently exist on general concepts of PV and inorganic PV materials and devices, few are available that offer a comprehensive overview of recently fast developing organic and polymeric PV materials and devices. Organic Photovoltaics: Mechanisms, Materials, and Devices fills this gap. The book provides an international perspective on the latest research in this rapidly expanding field with contributions from top experts around the world. It presents a unified approach comprising three sections: General Overviews; Mechanisms and Modeling; and Materials and Devices. Discussions include sunlight capture, exciton diffusion and dissociation, interface properties, charge recombination and migration, and a variety of currently developing OPV materials/devices. The book also includes two forewords: one by Nobel Laureate Dr. Alan J. Heeger, and the other by Drs. Aloysius Hepp and Sheila Bailey of NASA Glenn Research Center. Organic Photovoltaics equips students, researchers, and engineers with knowledge of the mechanisms, materials, devices, and applications of OPVs necessary to develop cheaper, lighter, and cleaner renewable energy throughout the coming decades.

Download or read book Progress in High Efficient Solution Process Organic Photovoltaic Devices written by Yang Yang and published by Springer. This book was released on 2015-02-17 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an important technique to process organic photovoltaic devices. The basics, materials aspects and manufacturing of photovoltaic devices with solution processing are explained. Solution processable organic solar cells - polymer or solution processable small molecules - have the potential to significantly reduce the costs for solar electricity and energy payback time due to the low material costs for the cells, low cost and fast fabrication processes (ambient, roll-to-roll), high material utilization etc. In addition, organic photovoltaics (OPV) also provides attractive properties like flexibility, colorful displays and transparency which could open new market opportunities. The material and device innovations lead to improved efficiency by 8% for organic photovoltaic solar cells, compared to 4% in 2005. Both academic and industry research have significant interest in the development of this technology. This book gives an overview of the booming technology, focusing on the solution process for organic solar cells and provides a state-of-the-art report of the latest developments. World class experts cover fundamental, materials, devices and manufacturing technology of OPV technology.

Download or read book Organic Solar Cells written by Wallace C.H. Choy and published by Springer. This book was released on 2012-11-17 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic solar cells have emerged as new promising photovoltaic devices due to their potential applications in large area, printable and flexible solar panels. Organic Solar Cells: Materials and Device Physics offers an updated review on the topics covering the synthesis, properties and applications of new materials for various critical roles in devices from electrodes, interface and carrier transport materials, to the active layer composed of donors and acceptors. Addressing the important device physics issues of carrier and exciton dynamics and interface stability and novel light trapping structures, the potential for hybrid organic solar cells to provide high efficiency solar cells is examined and discussed in detail. Specific chapters covers key areas including: Latest research and designs for highly effective polymer donors/acceptors and interface materials Synthesis and application of highly transparent and conductive graphene Exciton and charge dynamics for in-depth understanding of the mechanism underlying organic solar cells. New potentials and emerging functionalities of plasmonic effects in OSCs Interface Degradation Mechanisms in organic photovoltaics improving the entire device lifetime Device architecture and operation mechanism of organic/ inorganic hybrid solar cells for next generation of high performance photovoltaics This reference can be practically and theoretically applied by senior undergraduates, postgraduates, engineers, scientists, researchers, and project managers with some fundamental knowledge in organic and inorganic semiconductor materials or devices.

Download or read book Organic Solar Cells written by Liming Ding and published by John Wiley & Sons. This book was released on 2022-02-09 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic Solar Cells A timely and singular resource on the latest advances in organic photovoltaics Organic photovoltaics are gaining widespread attention due to their solution processability, tunable electronic properties, low temperature manufacture, and cheap and light materials. Their wide range of potential applications may result in significant near-term commercialization of the technology. In Organic Solar Cells: Materials Design, Technology and Commercialization, renowned scientist Dr. Liming Ding delivers a comprehensive exploration of organic solar cells, including discussions of their key materials, mechanisms, molecular designs, stability features, and applications. The book presents the most state-of-the-art developments in the field alongside fulsome treatments of the commercialization potential of various organic solar cell technologies. The author also provides: Thorough introductions to fullerene acceptors, polymer donors, and non-fullerene small molecule acceptors Comprehensive explorations of p-type molecular photovoltaic materials and polymer-polymer solar cell materials, devices, and stability Practical discussions of electron donating ladder-type heteroacenes for photovoltaic applications In-depth examinations of chlorinated organic and single-component organic solar cells, as well as the morphological characterization and manipulation of organic solar cells Perfect for materials scientists, organic and solid-state chemists, and solid-state physicists, Organic Solar Cells: Materials Design, Technology and Commercialization will also earn a place in the libraries of surface chemists and physicists and electrical engineers.

Download or read book Design Synthesis and Application of Novel Conjugated Materials Part II written by Haichang Zhang and published by Frontiers Media SA. This book was released on 2021-11-09 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Organic Photovoltaics written by Christoph Brabec and published by John Wiley & Sons. This book was released on 2014-02-20 with total page 766 pages. Available in PDF, EPUB and Kindle. Book excerpt: The versatility of organic photovoltaics is already well known and this completely revised, updated, and enlarged edition of a classic provides an up-to-date overview of this hot topic. The proven structure of the successful first edition, divided into the three key aspects of successful device design: materials, device physics, and manufacturing technologies, has been retained. Important aspects such as printing technologies, substrates, and electrode systems are covered. The result is a balanced, comprehensive text on the fundamentals as well as the latest results in the area that will set R&D trends for years to come. With its combination of both academic and commercial technological views, this is an optimal source of information for scientists, engineers, and graduate students already actively working in this field, and looking for comprehensive summaries on specific topics.

Download or read book The Impact of Interfaces on the Performance of Organic Photovoltaic Cells written by Roland Steim and published by KIT Scientific Publishing. This book was released on 2010 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic photovoltaic is an attractive technology to solve future energy supply scenarios. To further increase the potential of this technology novel absorber materials and interface materials have to be developed. In this work the paramount importance of interface materials for efficient as well as stable organic photovoltaic cells and modules is demonstrated. The general requirements of interface materials are elaborated and properties of a novel interface material which meets the demands are investigated experimentally and by simulations.

Download or read book Organic Photovoltaics written by Christoph Joseph Brabec and published by Springer Science & Business Media. This book was released on 2013-11-21 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present volume describes and explains the fundamentals of organic/plastic solar cells in a manner accessible to both researchers and students. It provides an up-to-date and comprehensive account of these materials and corresponding devices, which will play a key role in future solar energy systems.

Download or read book Phosphor Handbook written by Ru-Shi Liu and published by CRC Press. This book was released on 2022-01-31 with total page 585 pages. Available in PDF, EPUB and Kindle. Book excerpt: A benchmark publication, the first edition of the Phosphor Handbook, published in 1998, set the standard for references in the field. The second edition, updated and published in 2007, began exploring new and emerging fields. However, in the last 14 years, since the second edition was published, many notable advances and broader phosphor applications have occurred. Completely revised, updated, and expanded into three separate volumes, this third edition of the Handbook covers the most recent developments in phosphor research, characterization, and applications. This volume on ‘Experimental Methods for Phosphor Evaluation and Characterization’ addresses the theoretical and experimental methods for phosphor evaluation and characterization. The chapters in the book cover: First principle and DFT analysis of optical, structural, and chemical properties of phosphors Phosphor design and tuning through structure and solid solution Design for IR, NIR, and narrowband emission and thermally stable phosphors and nanophosphors Detailed illustration for measurement of the absolute photoluminescence quantum yield of phosphors Phosphor analysis through photoionization, high pressure, and synchrotron radiation studies

Download or read book Emerging Photovoltaic Materials written by Santosh K. Kurinec and published by John Wiley & Sons. This book was released on 2018-11-30 with total page 827 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the recent advances in photovoltaics materials and their innovative applications. Many materials science problems are encountered in understanding existing solar cells and the development of more efficient, less costly, and more stable cells. This important and timely book provides a historical overview, but concentrates primarily on the exciting developments in the last decade. It includes organic and perovskite solar cells, photovoltaics in ferroelectric materials, organic-inorganic hybrid perovskite, materials with improved photovoltaic efficiencies as well as the full range of semiconductor materials for solar-to-electricity conversion, from crystalline silicon and amorphous silicon to cadmium telluride, copper indium gallium sulfide selenides, dye sensitized solar cells, organic solar cells, and environmentally-friendly copper zinc tin sulfide selenides.

Download or read book Clean Electricity From Photovoltaics written by Mary D Archer and published by World Scientific. This book was released on 2001-06-04 with total page 870 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photovoltaic cells provide clean, reversible electrical power from the sun. Made from semiconductors, they are durable, silent in operation and free of polluting emissions. In this book, experts from all sectors of the PV community — materials scientists, physicists, production engineers, economists and environmentalists — give their critical appraisals of where the technology is now and what its prospects are./a

Download or read book Pathway Towards High Performance Organic Photovoltaics written by Thinh Le and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: State-of-the-art organic solar cells rely on kinetically trapped, partially phase separated structures of electron donor and acceptor blend mixtures. However, blend systems suffer from morphological instability and disorder near metal contacts which hamper device performance and lifetime. We demonstrate potential strategies to improve performance of organic photovoltaics via contact doping with polymer electrolytes and controlling the active layer morphology using fully conjugated block copolymers. We demonstrated that polymer acids can act as p-type dopants near electrode interfaces for active layers containing poly(3-hexylthiophene-2,5-diyl) (P3HT). By varying the pendant acidic groups across different backbones, we find the effectiveness of doping the conjugated polymer at the interface depends on the strength of the pendant acid group with stronger acid moieties being capable of creating more carriers in the doped system. Nevertheless, strong pendant acid groups also cause phase separation between dopants and conjugated polymers, thus hindering the doping effectiveness. The overall doping efficacy near electrodes therefore depends on the interplay between the strength of pendant acid groups and miscibility between polymeric dopants and conjugated polymers. To better control the active layer morphology and address morphological instability problem, we employed fully conjugated block copolymer composed of donor and acceptor blocks as active layer material. Previously, we have demonstrated that poly(3-hexylthiophene)blockpoly-((9,9-dioctylfluorene)-2,7-diyl-alt-[4,7-bis(thiophen-5-yl)-2,1,3-benzothiadiazole]-2,2-diyl) (P3HT-b-PFTBT) can self-assemble into 10 nm lamellae with alternating electron donor and acceptor domains. The resulting solar cell performance is approximately 3% which clearly outperforms blends of the same component obtained due to the self-assembly of the block copolymers. Nevertheless, one of the challenges in controlling the self-assembly of fully conjugated block copolymers is controlling the interplay between crystallization of the P3HT block and microphase separation between the donor and acceptor. To this end, we have examined the kinetics of the morphological evolution during two processes: solution casting and thermal annealing. We find that during film drying, P3HT crystallization happens on a much faster time scale than phase separation of the two blocks but the crystallization is significantly suppressed with respect to neat materials, enabling the microphase separation to proceed at time scales after crystallization of P3HT takes place. This enables the mesoscale structure to develop during processes such as thermal annealing, because self-assembly of the lamellar structure takes place before the crystallization of P3HT is complete. We also discover there is competitive crystallization between P3HT and PFTBT. In P3HT-b-PFTBT, P3HT crystallization dominates while PFTBT crystallization is either delayed or completely subdue, depending on the volume fraction of P3HT. The overall device performance strongly depends on the interplay between order phase formation in both P3HT and PFTBT. To further understand morphology evolution in block copolymer, we employed polarized resonant soft X-ray scattering (PSOXS) to study the interfacial molecular alignment in P3HT-b-PFTBT block copolymer. Using two different batches of block copolymer with different degree of P3HT crystallization, we found that in block copolymer where P3HT strongly crystallize, its harder to achieve lamellar morphology due to the formation of P3HT crystallites within a kinetically trapped P3HT and PFTBT amorphous matrix after solvent casting. High thermal annealing is required to provide enough energy to promote nanoscale phase separation and lamellae formation. However, the lamellar domains that formed at high temperature are highly-ordered with P3HT crystallites embedded inside. Here, P3HT chains aligned parallel with respect to lamellae domain interface. PSOXS also reveals the molecular orientation of P3HT crystallites within the P3HT lamellar domain. In block copolymer where P3HT crystallization is suppressed, weak P3HT crystallization allows for easier lamellae formation at low annealing temperature but at the cost of well-ordered phase separated domains.