Download or read book Device Fabrication and Material Design for High Performance Organic Photovoltaics Based on Non fullerene Acceptors with Bulky Flanking Side chains written by Yuan Chang and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Material Design and Device Fabrication for High performance Non fullerene Organic Photovoltaics written by Fujin Bai and published by . This book was released on 2021 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Material Design and Device Fabrication for High performance Non fullerene Organic Solar Cells written by Shangshang Chen and published by . This book was released on 2018 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterisation of Non Fullerene Electron Acceptors for Organic Photovoltaics written by Sarah Holliday and published by Springer. This book was released on 2018-03-22 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reports on the design, synthesis and characterization of new small molecule electron acceptors for polymer solar cells. Starting with a detailed introduction to the science behind polymer solar cells, the author then goes on to review the challenges and advances made in developing non-fullerene acceptors so far. In the main body of the book, the author describes the design principles and synthetic strategy for a new family of acceptors, including detailed synthetic procedures and molecular modeling data used to predict physical properties. An indepth characterization of the photovoltaic performance, with transient absorption spectroscopy (TAS), photo-induced charge extraction, and grazing incidence X-ray diffraction (GIXRD) is also included, and the author uses this data to relate material properties and device performance. This book provides a useful overview for researchers beginning a project in this or related areas.

Download or read book Design Synthesis and Application of Novel Conjugated Materials written by Haichang Zhang and published by Frontiers Media SA. This book was released on 2021-02-11 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ORGANIC PHOTOVOLTAICS written by Jon-Paul Sun and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent decades the demand for low-cost and sustainable energy sources has fueled the growth of photovoltaic research. Among the various photovoltaic technologies, organic semiconductors offer a light-weight and inherently-flexible solution that can be fabricated in a roll-to-roll process, significantly reducing fabrication and installation costs. Additionally, due to their transparent nature a number of previously unutilized architectural surfaces such as windows, building facades, and vehicle panels can be employed for energy production. Among solution-processed organic photovoltaics, fullerenes have dominated as the highest performing electron acceptor materials. However, their low absorption in the solar spectrum and high-energy synthesis is undesirable. Non-fullerene acceptors have the potential for low-cost synthesis while providing complementary absorption to the donor material, enhancing photocurrent. This dissertation presents the design, characterization, and integration into solar cells of novel non-fullerene acceptors. A family of related push-pull chromophores with phthalimide or naphthalimide end-groups, as well as perylene diimide-based acceptors were characterized using a combination of ultraviolet-visible absorption spectroscopy and ultraviolet photoemission spectroscopy. The acceptor molecules were integrated into thin-film transistors to measure field-effect mobilities. Solution-processed bulk heterojunction photovoltaic devices were fabricated and characterized using atomic force microscopy and by measuring current density-voltage curves and external quantum efficiencies while under illumination. The best performing devices achieved power conversion efficiencies of 5.5 %, where overall performance was limited by domain sizes in the blend films. Difficulties in forming nanoscale domain sizes in blend films are presented and discussed. A low-cost nanoembossing technique utilizing anodized aluminum oxide templates is presented to address the associated challenges with bulk heterojunctions. Initial results show that small-molecule acceptor films can be nanostructured prior to donor material deposition. This presents a viable method for fabricating large-area modules with predetermined nanoscale domain sizes, that is compatible with roll-to-roll processing.

Download or read book Understanding Fundamental Physical Properties of Non fullerene Acceptors for High Performance Organic Photovoltaics written by Chujun Zhang and published by . This book was released on 2022 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of non-fullerene acceptors (NFAs) promoted the progress of bulk heterojunction (BHJ) organic solar cells (OSCs) with remarkable power conversion efficiencies (PCEs) over 18%, push the OSCs field to a new phase. This thesis focuses on the emerging "Y-series" NFAs, presents the optical and electrical characterization of these high-performance OSCs materials and correlated the fundamental solid state properties with their molecule structure and OSCs performance. We first focus two A-DA'D-A type "Y" acceptors incorporating the same backbone skeleton and end groups but without (Y3) or with (Y18) alkyl side chains, and examine the alkyl side chains effects on their charge transport properties and device performance. We probe investigation into the fundamental interplay between their chemical structures and opto-electronic properties including the (i) charge transport, (ii) heat transfer, and (iii) electronic disorder. We found that the BHJ with Y18 possesses more efficient phonon transfer and charge transport as well as suppressed electronic disorder. Among these properties, the extremely low Urbach energy (EU) of 23 meV in Y18 stands out because it is even under the thermal energy (~26 meV) which sets the electronic disorder limit at room temperature. With all the contrasting results, a simple molecular model has rationalized in which the extra alkyl chains in Y18 help suppress the formation of rotamers, endowing it with a disorder-free molecular conformation and remarkable solid state properties. With the knowledge of the conformational effects of the molecules on the thermal properties, we further focused on the heat energy transfer of the organic materials relevant to organic semiconductor applications. Here, we probe heat diffusion properties of Y-series non-fullerene acceptors processing different DA'D framework, named BZ4F-5, BZ4F-6, and BZ4F-7, we found that backbone rings extension from five- to six- and seven-membered-fused rings trigger longer phonon mean free path and higher thermal diffusivities (D) in their pristine solid films and bulk heterojunction blends. Particularly, the correlation between the thermal transport properties in Y-series acceptors and their backbone geometry, molecule stacking, and thin-film crystallinity is demonstrated. More importantly, both organic thin-film transistors (OTFTs) and OSCs confirm that thermal durability of organic semiconductor devices correlated with the thermal properties of their active layer. Although BZ5F-6 and BZ4F-7 based devices possess similar device performance at room temperature, superior heat dissipation in BZ4F-7 molecule endows it with enhanced device lifetime.

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 Design and Synthesis of New Organic Semiconductors for Organic Solar Cells written by Xiaomei Ding and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular design and synthesis play critical roles in the development of organic semiconductors for organic photovoltaics (OPVs). This dissertation describes the design, synthesis, and characterization of three classes of organic semiconductors for OPVs: p-type semiconducting polymers, n-type semiconducting polymers, and non-fullerene small molecule acceptors. The relative merits of alternative building blocks and design strategies for organic semiconductors are investigated. Complex factors governing the underlying structure-property-processing-performance relationships are discussed in detail. The fundamentals of organic semiconductors and organic solar cells, state-of-the-art materials and devices, and challenges in the design and synthesis of materials are reviewed in Chapter 1. Chapter 2 discusses the strategy of selenophene substitution as a potential method to improve photovoltaic performance of the regular thiophene-based p-type semiconducting polymers. New selenophene-containing polymers were synthesized based on a widely used polymer, PBDB-T, where the original thiophene units at various side chain and backbone positions were substituted with selenophene. This study revealed the intramolecular and intermolecular interactions related with selenophene substitution, thus provided important guidelines in designing selenophene-containing polymers. Chapter 3 presents a comparative study of the alternating naphthalene diimide-thiophene copolymer, PNDIT-hd, and naphthalene diimide-selenophene copolymer, PNDIS-hd. The effects of selenophene substitution on the intrinsic and photovoltaic blend properties of n-type semiconducting naphthalene diimide-arylene copolymers with simple donor−acceptor architecture were investigated. This study demonstrated multiple advantages of selenophene substitution including enhancing light harvesting, formation of favorable morphology, and reducing charge recombination losses in all-polymer solar cell devices. Towards enhancing the intrinsic stability of small molecule acceptors, novel tridecacyclic ladder structure was designed and realized via Friedlander condensation reactions. The tridecacyclic ladder molecule acceptors (LMAs) described in Chapter 4 combined good solubility with enhanced stabilities and high photovoltaic performance. One of the new LMAs, LTX-4Cl, demonstrated a high PCE of 11.5% with high fill factor of 0.75. This study also unraveled the significant impact of side chains and halogenations on the molecular packing characteristics of the LMAs and the resulted photovoltaic performance. Finally, the results of the above studies are summarized in Chapter 5 and an outlook is given for future development of organic semiconductors and the organic photovoltaic technology.

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 Study of Device Physics and Active Layer Morphology in Polymer fullerene Based Solar Cells written by Guangye Zhang and published by . This book was released on 2015 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic photovoltaics (OPVs) are flexible, low cost and easily processable, which provides them with a very short energy payback time compared to most PV technologies and makes them strong candidates for industrial mass production. The richness of organic synthesis has afforded a large library of molecular semiconductors, among which the combination of conjugated polymers as electron donors and fullerenes as electron acceptors has been demonstrated to be the best sellers as building blocks of OPV devices. In the past few years, the majority of research focus on OPVs has been devoted to improving their power conversion efficiencies by using new combinations of polymer and fullerene materials. Most devices are based on blend-cast bulk heterojunctions (BHJs), in which a polymer and fullerene are mixed together in a solution that is then used to cast the active layer of the organic solar cell. Because the nm-scale morphology of the film depends on so many of the details of how it is cast, the device performance of blend-cast BHJ solar cells is hypersensitive to the processing kinetics of the active layer. Thus, for any new set of OPV materials, an Edisonian approach involving the fabrication of hundreds of blend-cast devices is needed to find the processing conditions that lead to the optimal morphology and best device performance. In this thesis, I will focus on two main contributions that I have made to help rationally design OPVs. First, our group recently has gone beyond the traditional method of simply blending the donor and acceptor material by developing a new technique to process the active layer of OPVs called sequential processing. This method takes advantage of a pair of quasi-orthogonal solvents to process the two components used in the active layer separately. By studying a series of crystalline polymers with controlled regioregularities and polydispersities, I have found that increasing polymer crystallinity produces the opposite behavior in BHJ solar cells fabricated by sequentially-processing and blend-casting. This suggests that the two processing techniques are complementary and provides guidance on selecting the appropriate processing technique for a given polymer. Second, I have studied the performance and device physics of a new series of controllably tuned fullerene derivatives applied in traditional blend-cast active layers. We obtained a series of carefully designed 1,4-dibenzyl fullerene bisadducts synthesized by our collaborators in Prof. Yves Rubin's group. The fullerenes have methoxy substituents selectively positioned on pendant phenyl rings, which allows us to examine the effect of the subtle molecular changes on both macroscopic solar cell performance and the underlying device physics. Through carrier recombination studies, I have learned that solar cell performance often depends on the material's surface energy and the vertical phase segregation caused by this surface energy in the active layer. The results will allow us to offer new directions on how to select the best device structure with a given new fullerene material. Finally, I have helped to make an interesting discovery during my study of the device physics of as-cast sequentially processed solar cells. I found that the specific type of vertical phase segregation in the as-cast devices gives rise to dark carriers, whose presence can be measured using the charge extraction by linear increasing voltage (CELIV) technique. The dark carriers directly clearly are created by the evaporation of metal electrodes because I found no such carriers when non-metal interfacial layers were inserted between the metal and the organic layer. Through capacitance analysis and transmission electron microscopy studies, we found this n-type doping is caused by metal penetration into the fullerene domain. These findings could have significant impact on determining device performance, explaining device physics and guiding future research directions.

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 Molecular Design and Synthesis of Non fullerene Acceptors for the High performance Organic Solar Cells written by Gaoda Chai and published by . This book was released on 2021 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comparing the Device Performance of Solar Cells Based on Polymers Mixed with Fullerene Polymer Blends and Block Copolymers written by Mario Palarino and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Conjugated polymers are candidates for use in low-cost electronics and photovoltaics. These organic materials could have myriad applications ranging from providing residential electricity to accessing and collecting data. The potential impact of such devices derives from the organic interfaces of the electron donor-acceptor heterojunctions. These interfaces, which are typically composed of fullerene-based acceptors, demonstrate efficient conversion between light and power. This work compares the efficiency of fullerene-based PCBM and non-fullerene-based PFTBT acceptors. To test fullerene-based acceptors, organic photovoltaic devices were constructed using P3HT/PCBM and PTB7/PCBM active layer combinations that were fabricated using glass substrates with an indium tin oxide (ITO) and PEDOT:PSS coated cathode combined with an evaporated aluminum anode. To test non-fullerene-based acceptors, various devices were created using P3HT/PFTBT and P3HT-b-PFTBT combinations. Experimental device efficiencies found for fullerene-based acceptors were higher than those found for non-fullerene-based acceptors.

Download or read book The Development of Semiconducting Materials for Organic Photovoltaics written by Jessica D. Douglas and published by . This book was released on 2013 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: The chemical structure of conjugated semiconducting materials strongly influences the performance of organic photovoltaic (OPV) devices. Thus a good understanding of the structure-function relationships that govern the optoelectronic and physical properties of OPV materials is necessary. In this dissertation, organic polymers and small molecules are evaluated in terms of OPV device output parameters, and molecular design rules are elucidated. The development of molecules with alternating electron-rich and electron-deficient backbone units provides materials with suitable optoelectronic properties for OPVs and favorable modularity for organic semiconductor design. The choice of specific aromatic units and side chains for conjugated materials are shown to modulate the energy levels and architecture of OPV devices, affecting each of the four mechanistic steps of OPV operation. In Chapter 2, the relationship between molecular packing parameters and the bulkiness of aliphatic solubilizing group extending away from a polymer backbone is elucidated, and high-performance OPV devices are achieved. In Chapter 3, the inclusion of a post-processing functionality on a polymer side chain is found to have a positive effect on the bulk morphology and overall performance of OPV devices. In Chapter 4, the influence of electron-withdrawing and quinoidal monomers on the optoelectronic properties of conjugated polymers is established, and energy level modulation is shown to affect the electron accepting and donating capabilities of OPV materials in a blended device. In Chapter 5, small molecules are designed with complementary light absorption properties in order to investigate a rarely observed charge generation mechanism.

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 Molecular Design of High performance Materials for Non fullerene Organic Solar Cells written by Jiaen Liang and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: