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 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 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 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 Photovoltaics Beyond Silicon written by Senthilarasu Sundaram and published by Elsevier. This book was released on 2024-06-28 with total page 818 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.
Download or read book Polymeric Solar Cells written by Frederik C. Krebs and published by DEStech Publications, Inc. This book was released on 2010 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Book offers a comprehensive treatment of nonhybrid polymeric solar cells from the basic chemistry of donor and acceptor materials through device design, processing and manufacture. Written by a team of Europe-based experts, the text shows the steps and strategies of successfully moving from the science of solar cells to commercial device production. Chapters focus on technologies that lead to increased efficiencies, longer usable life and lower costs. Highlighted are ways to fabricate solar cells from a range of polymers and develop them into marketable commodities. Special consideration is given to solar cells as intellectual property.
Download or read book Process structure property relationship of polymer fullerene bulk heterojunction films for organic solar cells written by Benjamin Schmidt-Hansberg and published by Cuvillier Verlag. This book was released on 2012-05-09 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photovoltaic (PV) is attracting increasing interest as an important contribution to renewable energy supply. Organic photovoltaic (OPV) is a comparable young PV technology with a great potential towards low cost solar power. This is due to the intrinsic advantage of the incorporated organic semiconductors which are soluble. Solution processing allows high throughput coating and printing processes. Hence, energy intensive high temperature and vacuum steps can be avoided which reduces the fabrication costs and keeps energy payback times low. The performance of organic solar cells strongly depends on the structure of the solution cast photoactive layer which comprises a polymer-fullerene blend. The blend structure evolves during the film drying step which has been studied in this thesis. Starting point of this work was the hypothesis that drying process parameters are suitable for systematically tuning the structure formation during drying of solution cast polymer-fullerene films in order to generate optimized structures with improved photovoltaic performance. For the evaluation of this hypothesis the structure formation of the polymer-fullerene system Poly(3-hexylthiophene-2,5-diyl):[6,6]-Phenyl C61-butyric acid methyl ester (P3HT:PCBM) was investigated incorporating i) thin film drying kinetics, ii) phase behavior of polymer-fullerene solutions, iii) structure formation and iv) the drying process-structure-property relationship of solar cells. The generality of the obtained results has been studied in comparison with the behavior of Poly{[4,40-bis(2-ethylhexyl)dithieno(3,2-b;20,30-d)silole]-2,6-diyl-alt-(2,1,3-benzothidiazole)-4,7-diyl} (PSBTBT). i) Within this thesis a dedicated coating and drying setup was developed which afforded precisely defined coating and drying process conditions as prerequisite for all obtained results. For the first time, the drying behavior of finally a few hundred nanometer thin films could be investigated at five measurement positions with laser reflectometry simultaneously. This allowed the elaboration of a spatially resolved numerical thin film drying model. ii) In conjunction with the measurement and simulation of the evolution of film composition it was required to determine important instants of phase transitions such as solubility limits. Therefore the binodal region of P3HT solutions has been determined in the temperature range of 0°C-60°C. Within the unstable region P3HT solutions phase separate into a sol and a gel phase. The fullerene PCBM exhibits only a single solubility limit. iii) In order to correlate the expected phase transitions according to the phase diagrams with the real structure formation, the above mentioned coating and drying setup was combined with synchrotron based in situ grazing incidence X-ray diffraction (GIXD) measurements. This gave unique insights into the mechanisms and dynamics of polymer-fullerene blend crystallization. After reaching P3HT solubility the crystallization proceeded with well-oriented interface-induced P3HT nucleation followed by P3HT crystal growth with increasing orientation distribution of the crystallites and PCBM aggregation in the final drying period. Furthermore strong polymer-fullerene interaction forces could be derived. By increasing the PCBM fraction it could be shown for the 1:2 P3HT:PCBM ratio that PCBM molecules brake the (020) π-π-stacking of P3HT lamellae which signifies a dramatic loss of hole mobility and consequently reduced device performance. It is further notable that increasing drying temperatures reduce the amount of (020) π-π-stacked P3HT molecules but lead to an increased amount of P3HT (100) crystallinity. Hence, drying temperature determines the preferred direction of crystal growth. iv) Besides a finer degree of phase separation, reduced drying temperatures also cause a higher amount of π-π-stacked polymers, longer effective polymer conjugation length, increased amount of vertical charge transport pathways and an increasingly rough topography due to larger polymer aggregates. Jointly this leads to improved power conversion efficiency at lower drying temperatures. Based on the elaborated knowledge a strategy for a 40% reduction of drying time with only small drawbacks in solar cell performance could be developed. Finally it was important to investigate the transferability of the obtained knowledge to other material systems. PSBTBT:PC71BM blends show similarities to that of P3HT:PCBM with partly interface induced polymer nucleation and subsequent fullerene aggregation in the final drying stage. The kinetics of molecular ordering however proceed fast enough such that the drying process under the investigated conditions cannot limit the structure formation. Hence, P3HT:PCBM is a suitable model system due to its sensitivity to many process parameters. According to the process influence on novel materials the results of this thesis can serve as a source for appropriate process strategies.
Download or read book Molecular Engineering on Semiconducting Polymers for Enhancing Solar Cell Performance written by Wei-Hsuan Chang and published by . This book was released on 2016 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: A promising solution to address the present-day energy crisis is photovoltaic technology. Currently, the market is dominated by inorganic-based materials such as silicon, III-V semiconductors, CIGS, etc. Despite their technical maturity, the energy generated from these devices is still low. This is partially due to the high production cost of these materials. Therefore, the search for next generation photovoltaic technologies that utilize earth-abundant elements with low-cost production processes has been an intensive research area. Using solution-processable organic polymer semiconductors, polymer solar cells provide an opportunity to efficiently generate energy from sunlight at a reasonable cost. This is due to the ease of synthesis/modification of organic molecules and polymers compared to that of inorganic materials, the easily scalable solution-based fabrication process, and the use of cost-effective, environmentally friendly carbon-based elements. Owing to the vast research efforts over the past decade, the power conversion efficiencies of single- and multi-junction polymer solar cells have recently surpassed the 10% milestone. During this progression, materials development, driven by the desire to overcome the constraint of P3HT, has played a very important role in advancing the technology. To date, hundreds of photovoltaic polymers have been made through different combinations of conjugated building blocks and suitable functional groups. As a result, several state-of-the-art polymers, such as PTB7, PDPP3T, PBDTDPP and PffBT4T, have shown impressive performance. In order to keep this momentum going, further improvements and deeper insights into materials' property are certainly needed. In this dissertation, we particularly focus on improving the properties of several state-of-the-art photovoltaic polymers by resolving their shortcomings using innovative organic synthetic approaches. It is demonstrated that the materials' optoelectronic property as well as their fabrication process can be alternated through chemistry modification at a molecular scale, that is, by molecule engineering. This study paves a way not only to achieve high performance polymer solar cells, but also to provide novel synthetic strategies for researchers in the field to further push the boundaries of polymer solar cell technology in the future.
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 Fabrication and Characterization of Low Cost Solar Cells based on Earth Abundant Materials for Sustainable Photovoltaics written by Mahmoud Abdelfatah and published by Cuvillier Verlag. This book was released on 2016-07-08 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The low cost and low temperature electrochemical deposition technique was employed to grow Cu2O thin films and ZnO:Al thin films were deposited by d.c. magnetron sputtering in order to fabricate solar cells. The potentiostatic and galvanostatic electrodeposition modes were used to deposit the Cu2O thin films. Raman spectra of thin films have shown characteristic frequencies of crystalline Cu2O. The contact between Cu2O and Au is found to be an Ohmic contact. The devices grown by a potentiostatic mode have higher efficiency than those grown by a galvanostatic mode. The optimum thickness of Cu2O thin films as an absorber layer in solar cells. was found to be around 3 µm respect to a high efficiency. Flexible and light weight solar cell was fabricated on plastic substrate.
Download or read book Fiber Solar Cells written by Shaocong Hou and published by Springer. This book was released on 2017-01-23 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the fundamental research and latest findings on novel flexible/wearable photovoltaic technology, and comprehensively summarizes the rapid developments in flexible photovoltaics, from traditional planar solar cells to fiber solar cells. It discusses the rational design of fiber solar cell materials, electrodes and devices, as well as critical factors including cost, efficiency, flexibility and stability . Furthermore, it addresses fundamental theoretical principles and novel fabrication technologies and their potential applications. The book provides practical information for university researchers and graduate students interested in flexible fiber photovoltaics, and inspires them to design other novel flexible/wearable electronics and textiles.
Download or read book Next Generation Solar Cells written by Yoon-Bong Hahn and published by CRC Press. This book was released on 2023-08-10 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses the principles and materials for the development of next-generation solar cells for a sustainable global society Discusses the structures, working principles, and limitations of solar cells as well as the improvement methods of their power-conversion efficiency Introduces generations of cells as photovoltaic devices, including third-generation solar cells such as organic solar cells, quantum dots solar cells, and organic–inorganic hybrid solar cells Focuses on the emerging perovskite solar cells (PSCs) and deals with their cell configuration, transport materials, and fabrication processes in detail.
Download or read book Rational Design of Solar Cells for Efficient Solar Energy Conversion written by Alagarsamy Pandikumar and published by John Wiley & Sons. This book was released on 2018-09-05 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: An interdisciplinary guide to the newest solar cell technology for efficient renewable energy Rational Design of Solar Cells for Efficient Solar Energy Conversion explores the development of the most recent solar technology and materials used to manufacture solar cells in order to achieve higher solar energy conversion efficiency. The text offers an interdisciplinary approach and combines information on dye-sensitized solar cells, organic solar cells, polymer solar cells, perovskite solar cells, and quantum dot solar cells. The text contains contributions from noted experts in the fields of chemistry, physics, materials science, and engineering. The authors review the development of components such as photoanodes, sensitizers, electrolytes, and photocathodes for high performance dye-sensitized solar cells. In addition, the text puts the focus on the design of material assemblies to achieve higher solar energy conversion. This important resource: Offers a comprehensive review of recent developments in solar cell technology Includes information on a variety of solar cell materials and devices, focusing on dye-sensitized solar cells Contains a thorough approach beginning with the fundamental material characterization and concluding with real-world device application. Presents content from researchers in multiple fields of study such as physicists, engineers, and material scientists Written for researchers, scientists, and engineers in university and industry laboratories, Rational Design of Solar Cells for Efficient Solar Energy Conversion offers a comprehensive review of the newest developments and applications of solar cells with contributions from a range of experts in various disciplines.
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 2015-02-26 with total page 417 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 WOLEDs and Organic Photovoltaics written by Vivian W. W. Yam and published by Springer Science & Business Media. This book was released on 2010-11-19 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: A major global issue that the world is facing today is the upcoming depletion of fossil fuels and the energy crisis. In 1998, the global annual energy consumption was 12. 7 TW; of which 80% was generated from fossil fuels. This also translates into huge annual emissions of CO that leads to massive environmental problems, 2 particularly the global warming, which could be disastrous. Future global annual energy needs are also estimated to rise dramatically. A major challenge confronting the world is to ?nd an additional 14–20 TW by 2050 when our energy reserves based on fossil fuels are vanishing. The massive demand for energy would require materials and/or processes that would help to provide new sources of clean ren- able energy or to develop processes that would harvest energy or to better utilize energy in an ef?cient manner. The present monograph, WOLEDs and Organic Photovoltaics – Recent Advances and Applications, focuses on a very important and timely subject of topical interest that deals with the more ef?cient use of energy through white organic light-emitting diodes (WOLEDs) for solid-state lighting and the development of clean sources of renewable energy through the harvesting of light energy for conversion into electrical energy in organic photovoltaics. While LED solid-state lighting and photovoltaics have been dominated by inorganic semiconductor materials and silicon-based solar cells, there have been growing interests in the development of WOLEDs and organic photovoltaics.
Download or read book Optical Properties and Applications of Semiconductors written by Inamuddin and published by CRC Press. This book was released on 2022-07-18 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductors with optical characteristics have found widespread use in evolving semiconductor photovoltaics, where optical features are important. The industrialization of semiconductors and their allied applications have paved the way for optical measurement techniques to be used in new ways. Due to their unique properties, semiconductors are key components in the daily employed technologies in healthcare, computing, communications, green energy, and a range of other uses. This book examines the fundamental optical properties and applications of semiconductors. It summarizes the information as well as the optical characteristics and applicability of semiconductors through an in-depth review of the literature. Accomplished experts in the field share their knowledge and examine new developments. FEATURES Comprehensive coverage of all types of optical applications using semiconductors Explores relevant composite materials and devices for each application Addresses the optical properties of crystalline and amorphous semiconductors Describes new developments in the field and future potential applications Optical Properties and Applications of Semiconductors is a comprehensive reference and an invaluable resource for engineers, scientists, academics, and industry R&D teams working in applied physics.
Download or read book Device Interface Process and Electrode Engineering Towards Low Cost and High Efficiency Polymer Solar Cells in Inverted Structure written by Jingyu Zou and published by . This book was released on 2013 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a promising technology for economically viable alternative energy source, polymer solar cells (PSCs) have attracted substantial interests and made significant progress in the past few years, due the advantages of being potentially easily solution processed into large areas, flexible, light weight, and have the versatility of material design. In this dissertation, an integrated approach is taken to improve the overall performance of polymer solar cells by the development of new polymer materials, device architectures, interface engineering of the contacts between layers, and new transparent electrodes. First, several new classes of polymers are explored as potential light harvesting materials for solar cells. Processing has been optimized and efficiency as high as 6.24% has been demonstrated. Then, with the development of inverted device structure, which has better air stability by utilizing more air stable, high work function metals, newly developed high efficiency polymers have been integrated into inverted structure device with integrated engineering approach. A comprehensive characterization and optical modeling based on conventional and inverted devices have been performed to understand the effect of device geometry on photovoltaic performance based on a newly developed high performance polymer poly(indacenodithiophene-co-phananthrene-quinoxaline) (PIDT-PhanQ). By modifying anode with a bilayer combining graphene oxide (GO) and poly(3,4-ethylenedioxylenethiophene):poly(styrenesulfonic acid) (PEDOT:PSS) as hole transporter/electron blocker, it further improved device performance of inverted structured to 6.38%. A novel processing method of sequentially bilayer deposition for active layer has been conducted based on a low band-gap polymer poly[2, 6-(4, 4-bis-(2-ethylhexyl)-4H-cyclopenta [2,1-b;3,4-bʹ] dithiophene)-alt-4,7-(2, 1, 3- fluorobenzothiadiazole)] (PCPDT-FBT). Inverted structure devices processed from bilayer deposition shows even higher performance than bulk-heterojunction. Polymer and fullerene distribute uniformly throughout the layer in vertical direction. Better electron mobility and better crystallinity in inverted bilayer film bas been observed, which can contribute to the higher IQE in inverted bilayer device. Metal grid/conducting polymer hybrid transparent electrode has been proved can be an alternative to ITO in inverted structure with similar device performance. Further, a novel protocol to fabricate highly transparent ultra thin silver films as transparent electrode on both glass and plastic substrates also has been demonstrated, based on ZnO/Ag/ZnO tri-layer structure and self-assembled monolayer interfacial modification. Sophisticated interfacial engineering method is applied at necessary interfaces to functioning the ultra thin silver film as a platform for polymer solar cells, and superior device performance that even exceeds using ITO has been achieved.
