Transparent Conductive Oxides for Organic Photovoltaics PDF Download

Author: Graham Murdoch
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Graham Blair Murdoch
Publisher:
ISBN: 9780494675519
Category :
Languages : en
Pages : 168

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Book Description
Organic solar cells and organic light emitting diodes are on the forefront of emerging technologies aimed at harnessing light in ways never thought possible. Large-area installations of OLED solid state lighting (SSL), as well as organic photovoltaics (OPVs), will become possible as the efficiencies of these devices continue to rise. All organic solar cells and OLEDs require the use of transparent conductive electrodes. Indium oxide (ITO) is currently the transparent conductor of choice for these applications, due to its unique combination of transparency, high conductivity, durability, and favourable surface properties.Indium, however, is a rare and expensive metal; proposed large-area installations of OPV cells and OLEDs will add further strain to global indium supply. Transparent conductive materials that are abundant, inexpensive, and which enable efficient and robust organic devices must therefore be developed. In the present work, suitable ITO anode replacement materials are demonstrated for OLEDs, small-molecule, polymer, and PbS colloidal quantum dot photovoltaics.

Author: David S. Ginley
Publisher: Springer Science & Business Media
ISBN: 1441916385
Category : Technology & Engineering
Languages : en
Pages : 537

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Transparent conducting materials are key elements in a wide variety of current technologies including flat panel displays, photovoltaics, organic, low-e windows and electrochromics. The needs for new and improved materials is pressing, because the existing materials do not have the performance levels to meet the ever- increasing demand, and because some of the current materials used may not be viable in the future. In addition, the field of transparent conductors has gone through dramatic changes in the last 5-7 years with new materials being identified, new applications and new people in the field. “Handbook of Transparent Conductors” presents transparent conductors in a historical perspective, provides current applications as well as insights into the future of the devices. It is a comprehensive reference, and represents the most current resource on the subject.

Author: Marwa Abd-Ellah
Publisher:
ISBN:
Category : Nanostructured materials
Languages : en
Pages : 149

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In Ontario, there are great incentives to invest in solar cell research through the Feed-In Tariff program, which has successfully increased the total connected capacity of solar power in Ontario to well over 215 MW. Extensive studies have been conducted on fabrication of efficient solar cells, with the most mature technology being silicon-based solar cells. However, other types of solar cells have been introduced as alternatives to silicon based solar cells due to their laborious work, energy consumption, and high cost of production. Different inorganic and organic photovoltaic systems including dye-sensitized, organic/polymer, quantum-dot, and hybrid nanocrystal/polymer hetero-junctions solar cells have been proposed to provide comparable efficiencies. Transparent conductive oxides are usually the main component in any solar system because of its role as an electrode photoanode, acting as a diffusion barrier and an open-circuit voltage attenuator. These are due to their high electrical conductivity, wide optical transmittance, and relatively ease of synthesis. As a result, a rich amount of studies on their synthesis, modification, and application as photo-catalytic electrodes, gas sensors, photonic crystals, and solar cell photoanodes exists in the literature. Their use in photovoltaics as thin film materials has since evolved into nanostructured films, as numerous studies have showed that the material morphology is an important parameter in improving solar cell performance. Many nanostructured transparent conductive oxide films have been extensively investigated for use as an n-type semiconductor in a p-n junction solar cell system or as a photoanode in a dye-sensitized solar cell (DSSC). Thus far these applications have proven challenging in terms of achieving high device efficiencies, particularly by taking advantage of their inherently higher surface area-to-volume ratio, better photon harvesting, and enhanced interparticle charge transport with shorter diffusion lengths across the device structure. With a large direct band gap (3.37 eV), a large exciton binding energy (60 m eV), and high electron mobility (120 cm2 V-1 s-1), zinc oxide (ZnO) is considered an excellent candidate as an (n-type) transparent semiconducting material at room temperature for photovoltaic application. In the present work, two different ZnO nanostructural morphologies are prepared by controlling the electrolyte conductivity using a direct, catalyst- and seed-layer free electrodeposition method. The effect of deposition time and temperature on the growth of the high-specific-surface-area ZnO nanotubes electrodeposited is studied. Furthermore, the morphology, crystallinity, and chemical composition of the resulting ZnO nanotubes and nanorods are fully characterized with a proposed model of their growth mechanism. These one-dimensional ZnO nanostructures are then employed as an n-type semiconductor, along with a p-type Cu2O thin film, to fabricate an inorganic p-n junction solar cell. As an important step to improve device performance, the electrical and optical properties of the p-type Cu2O film are optimized by simple annealing. Two different device structures, consisting of the electrodeposited ZnO nanorods and nanotubes grown on the top of a thick n-type ZnO seed layer (500 nm) covered by an optimized (2.5[mu]m) p-type Cu2O layer (in order to provide the full built-in potential across the junction area), are fabricated. The relations of structural morphology (i.e. nanotube vs nanorod) and characteristic solar cell parameters are investigated. The new device architecture is found to offer minimum leakage path and reduced recombination loss expected in a typical nanostructure-based solar cell. A photon-to-electron conversion efficiency (PCE) of 0.8 % is obtained for ZnO nanotubes compared to other traditional one-dimensional nanostructures (i.e. nanorods or nanowires) that is due to the increased junction area and the better charge collection. These results illustrate the advantage of single-step electrodeposition of ZnO nanotubes, which provide a larger interfacial area and a much lower defect density than previously reported nanotubes obtained by etching ZnO nanorods. Taking advantage of their higher electron dynamics than the classical TiO2, ZnO and SnO2 are employed as photoanode materials to fabricate an organic DSSC system. To further improve the optical absorption, the effects of surface modification using gold nanoparticles to ZnO nanotubes are investigated. Different gold electrolyte concentrations are used to manipulate the plasmonic nanoparticle size while deposition time is used to control the aerial density. These studies lead to a significant increase in the PCE for DSSC based on ZnO nanotubes with gold nanoparticle modification (6%) when compared to that with pristine ZnO nanotubes (4.7%). Surface decoration with plasmonic gold nanoparticles therefore provides an efficient approach to creating not only high surface area for superior loading of dye molecules but also enhanced absorption specifically in the visible range by taking advantage of their surface plasmon resonance effect. Hierarchical one-dimensional SnO2 nanostructures are also employed as photoanode material for DSSC application. With a band gap of 3.8 eV, low UV degradation characteristic and generally high thermal and chemical stability, SnO2 is also an excellent photoanode alternative to TiO2. Almost 10-fold enhancement of PCE (3.6%) when compared with pristine SnO2 nanobelts with (0.48%) is obtained for these hierarchical SnO2 nanostructures. This significant improvement is in part due to better dye loading of highly branched nanostructures. Additional surface passivation has also been performed on the as-deposited hierarchical SnO2 nanostructures by dip-coating with an MgO passivation layer of appropriately optimized thickness. Such an insulating layer is found to effectively reduce the recombination loss process caused by the higher electron mobility of SnO2 photoanode nanostructures. This MgO-passivation treatment further enhances the PCE to (4.14%). The present work therefore shows that one-dimensional ZnO and SnO2 nanostructures provide a viable, powerful platform for developing the next-generation photovoltaic devices. This study further demonstrates the novel techniques used to significantly enhance the PCEs for both inorganic p-n junction solar cell and organic DSSC.

Author: Klaus Ellmer
Publisher: Springer
ISBN: 9783540840961
Category : Technology & Engineering
Languages : en
Pages : 446

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Book Description
Zinc oxide (ZnO) belongs to the class of transparent conducting oxides that can be used as transparent electrodes in electronic devices or heated windows. In this book the material properties of, the deposition technologies for, and applications of zinc oxide in thin film solar cells are described in a comprehensive manner. Structural, morphological, optical and electronic properties of ZnO are treated in this review.

Author: Christoph Brabec
Publisher: John Wiley & Sons
ISBN: 3527623205
Category : Technology & Engineering
Languages : en
Pages : 597

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Providing complementary viewpoints from academia as well as technology companies, this book covers the three most important aspects of successful device design: materials, device physics, and manufacturing technologies. It also offers an insight into commercialization concerns, such as packaging technologies, system integration, reel-to-reel large scale manufacturing issues and production costs. With an introduction by Nobel Laureate Alan Heeger.

Author: Barry P. Rand
Publisher: CRC Press
ISBN: 9814463663
Category : Science
Languages : en
Pages : 795

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Organic photovoltaic (OPV) cells have the potential to make a significant contribution to the increasing energy needs of the future. In this book, 15 chapters written by selected experts explore the required characteristics of components present in an OPV device, such as transparent electrodes, electron- and hole-conducting layers, as well as elect

Author: David Levy
Publisher: John Wiley & Sons
ISBN: 3527342079
Category : Technology & Engineering
Languages : en
Pages : 390

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Edited by well-known pioneers in the field, this handbook and ready reference provides a comprehensive overview of transparent conductive materials with a strong application focus. Following an introduction to the materials and recent developments, subsequent chapters discuss the synthesis and characterization as well as the deposition techniques that are commonly used for energy harvesting and light emitting applications. Finally, the book concludes with a look at future technological advances. All-encompassing and up-to-date, this interdisciplinary text runs the gamut from chemistry and materials science to engineering, from academia to industry, and from fundamental challenges to readily available applications.

Author: Hyesung Park (Ph. D.)
Publisher:
ISBN:
Category :
Languages : en
Pages : 191

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Graphene, a hexagonal arrangement of carbon atoms forming a one-atom thick planar sheet, has gained much attention due to its remarkable physical properties. Apart from the micromechanical cleavage of highly ordered pyrolytic graphite (HOPG), several alternate methods have been explored to achieve reliable and repeatable synthesis of large-area graphene sheets. Among these, the chemical vapor deposition (CVD) process has been demonstrated as an efficient way of producing continuous, large area graphene films and the synthesis of graphene sheets up to 30-inch has been reported. Similar to graphene research, solar cells based on organic materials have also drawn significant attention as a possible candidate for the generation of clean electricity over conventional inorganic photovoltaics due to the interesting properties of organic semiconductors such as high absorption coefficients, light weight and flexibility, and potentially low-cost, high throughput fabrication processes. Transparent conducting electrodes (TCE) are widely used in organic photovoltaics, and metal oxides such as indium tin oxide (ITO) have been commonly used as window electrodes. Usually used as thin films, these materials require low sheet resistance (Rsh) with high transparency (T). Currently the dominant material used in the industry standard is ITO. However, these materials are not ideal options for organic photovoltaic applications due to several reasons: (1) non-uniform absorption across the visible to near infrared region; (2) chemical instability; (3) metal oxide electrodes easily fracture under large bending, and they are not suitable for flexible solar cell applications; (4) limited availability of indium on the earth leading to increasing costs with time. Therefore, the need for alternative/replacement materials for ITO is ever increasing and ideally need to be developed with the following characteristics: low-cost, mechanically robust, transparent, electrically conductive, and ultimately should demonstrate comparable or better performance compared to ITO-based photovoltaic devices. With superior flexibility and good electrical conductivity, as well as abundance of source material (carbon) at lower costs compared to ITO, in this thesis, we propose that the CVD graphene can be a suitable candidate material as TCE in organic photovoltaic applications, satisfying the aforementioned requirements.

Author: Vijay Kumar
Publisher: Elsevier
ISBN: 0323993672
Category : Technology & Engineering
Languages : en
Pages : 676

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Metal Oxides for Next Generation Optoelectronic, Photonic and Photovoltaic Applications focuses on the optoelectronic, photonic and photovoltaic behaviors of metallic oxides and closely related phenomena, from elementary principles to the latest findings. Each chapter includes a comprehensive evaluation of the synthesis and characterization of the most relevant metal oxides nanostructures for each application. In addition, there is a focus on methods to tune the materials’ properties in order to improve devices performance. This book is suitable for researchers and practitioners in academia and industry working in the disciplines of materials science and engineering, chemistry and physics. Metal oxides are widely used in various optoelectronic devices, photonics, display devices, smart windows, sensors, optical components, energy-saving, and harvesting devices. Each application requires materials with their own specific properties. By controlling the particle size, shape, crystal structure, one can tune various properties of metal oxides viz. bandgap, absorption properties, conductivity, which alter the material for the specific application. Includes discussions of synthesis and characterization of metal oxides materials for applications in next-generation optoelectronic, photonic and photovoltaic devices Emphasizes material design strategies of metal oxide nanostructures Focuses on the optoelectronic, photonic and photovoltaic behaviors of metallic oxides and closely related phenomena, from elementary principles to the latest findings