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Long-term Stability of Organic Solar Cells

Author : Subarna Babu Sapkota

Publisher :

Page : pages

File Size : 31,36 MB

Release : 2015

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ISBN :

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Zusammenfassung: Organic solar cells bear the potential to be used as flexible, light weight and cheap source of renewable energy. Efficiency, long lifetime and low cost are the important factors for the successful application of this technology. Significant improvement in the power conversion efficiency in the past few years brought lifetime of organic solar cells into focus. Encapsulation assists to achieve long lifetime by protecting organic solar cells against different aging factors like oxygen and moisture. Understanding of degradation mechanisms further helps to develop different strategies to prolong the lifetime.The experimental work of this thesis is divided into two parts. The first part deals with the evaluation of various encapsulation and barrier materials under different aging conditions such as elevated temperature, continuous illumination, UV stress, damp heat and outdoor exposure. In the second part, detailed investigations of degradation mechanisms under different aging conditions (mainly under UV-stress and damp heat) and strategies how to minimize the degradation are presented.A promising lifetime of more than 12 000 hours both under elevated temperature of 85°C, ambient air in the dark and continuous illumination of 1000 W/m2 was demonstrated with less than 10 % degradation for encapsulated devices. Similar devices showed less than 20 % degradation after one complete year of outdoor exposure. Further, completely flexible encapsulated devices also exhibited > 95 % of their initial device performance after 1000 hours of aging under damp heat, successfully fulfilling the standard test condition set by the IEC61646 under 85°C/85 % rh.In contrast, devices exhibited comparably fast degradation in presence of UV radiation resulting in more than 50 % degradation within 1000 hours of aging. The observed degradation under UV radiation was found to be characterized by a drop in fill factor and short circuit current density. Additional experiments revealed an increase in the sheet resistance of the PEDOT:PSS hole transport layer. Numerical simulations based on an effective semiconductor model using experimentally observed sheet resistance values were carried out. Simulation results were found to be in good agreement with experimental observations. The use of high conductive or UV stable PEDOT:PSS formulations, high post annealing temperature ensuring better removal of moisture or an additional UV filter were proven as possible routes for retarding the UV-induced degradation



Flexible Solar Cells

Author : Mario Pagliaro

Publisher : John Wiley & Sons

Page : 202 pages

File Size : 22,95 MB

Release : 2008-11-21

Category : Technology & Engineering

ISBN : 3527623795

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Book Description

With the decline in the world's natural resources, the need for new and cheaper energy sources is evolving. One such source is the sun which generates heat and light which can be harnessed and used to our advantage. This reference book introduces the topic of photovoltaics in the form of flexible solar cells. There are explanations of the principles behind this technology, the engineering required to produce these products and the future possibilities offered by this technology. The chemistry and physics of the cells (both organic and inorganic) are clarified as well as production methods, with information how this can then be applied to the nanoscale as well. A complete guide to this new and exciting way of producing energy which will be invaluable to a variety of people from material scientists, chemists, electrical engineers, to management consultants and politicians.



Understanding Degradation Mechanisms and Improving Long-term Performance of Organic Solar Cells

Author : William Robert Mateker

Publisher :

Page : pages

File Size : 39,9 MB

Release : 2016

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Organic photovoltaics (OPVs) attract interest because they can be printed rapidly and at low cost. Over the past decade, research directed towards increasing the initial power conversion efficiency has pushed the record device efficiency above 10%. However, in order to be a competitive technology, the performance must remain relatively stable over time. In this talk, I discuss mechanisms of degradation in materials and solar cells as well as suggest materials properties that will improve stability. First I discuss the bleaching of the absorber materials in air. I will show that dense, ordered film morphologies can stabilize materials -- in one case, by a factor of 2000. Next, I show that temperature induced degradation can occur in well-encapsulated solar cells when the materials have glass transition temperatures at or below operating conditions. Similarly, I discuss the effect of mobile molecules present in the films and show that purification aimed at reducing their content can improve thermal stability. In a solar cell made from a polymer with a high glass transition temperature, lifetimes can exceed 20 years. Finally, I discuss the light-induced degradation that occurs in the first several hundred hours of solar cell operation, even in the absence of oxygen. This degradation can reduce the short circuit current via a fullerene dimerization reaction, or it can reduce the open circuit voltage via the introduction of energetic disorder on the semiconducting polymer. I show that both degradation modes are reduced in films with a more ordered morphology. These findings provide guidelines for reducing thermal and photo-induced degradation and improving the long-term stability of OPVs.



Organic Solar Cells

Author : Liming Ding

Publisher : John Wiley & Sons

Page : 988 pages

File Size : 16,29 MB

Release : 2022-02-09

Category : Technology & Engineering

ISBN : 3527833668

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Book Description

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.



Stability and Degradation of Organic and Polymer Solar Cells

Author : Frederik C. Krebs

Publisher : John Wiley & Sons

Page : 375 pages

File Size : 33,36 MB

Release : 2012-04-23

Category : Technology & Engineering

ISBN : 1119952514

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Book Description

Organic photovoltaics (OPV) are a new generation of solar cells with the potential to offer very short energy pay back times, mechanical flexibility and significantly lower production costs compared to traditional crystalline photovoltaic systems. A weakness of OPV is their comparative instability during operation and this is a critical area of research towards the successful development and commercialization of these 3rd generation solar cells. Covering both small molecule and polymer solar cells, Stability and Degradation of Organic and Polymer Solar Cells summarizes the state of the art understanding of stability and provides a detailed analysis of the mechanisms by which degradation occurs. Following an introductory chapter which compares different photovoltaic technologies, the book focuses on OPV degradation, discussing the origin and characterization of the instability and describing measures for extending the duration of operation. Topics covered include: *Chemical and physical probes for studying degradation *Imaging techniques *Photochemical stability of OPV materials *Degradation mechanisms *Testing methods *Barrier technology and applications Stability and Degradation of Organic and Polymer Solar Cells is an essential reference source for researchers in academia and industry, engineers and manufacturers working on OPV design, development and implementation.





Organic Photovoltaics

Author : Sam-Shajing Sun

Publisher : CRC Press

Page : 916 pages

File Size : 34,6 MB

Release : 2017-12-19

Category : Technology & Engineering

ISBN : 1351837060

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Book Description

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.



Stability and Degradation of Organic and Polymer Solar Cells

Author : Frederik C. Krebs

Publisher : John Wiley & Sons

Page : 375 pages

File Size : 47,41 MB

Release : 2012-04-02

Category : Technology & Engineering

ISBN : 1118312236

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Book Description

Organic photovoltaics (OPV) are a new generation of solar cells with the potential to offer very short energy pay back times, mechanical flexibility and significantly lower production costs compared to traditional crystalline photovoltaic systems. A weakness of OPV is their comparative instability during operation and this is a critical area of research towards the successful development and commercialization of these 3rd generation solar cells. Covering both small molecule and polymer solar cells, Stability and Degradation of Organic and Polymer Solar Cells summarizes the state of the art understanding of stability and provides a detailed analysis of the mechanisms by which degradation occurs. Following an introductory chapter which compares different photovoltaic technologies, the book focuses on OPV degradation, discussing the origin and characterization of the instability and describing measures for extending the duration of operation. Topics covered include: Chemical and physical probes for studying degradation Imaging techniques Photochemical stability of OPV materials Degradation mechanisms Testing methods Barrier technology and applications Stability and Degradation of Organic and Polymer Solar Cells is an essential reference source for researchers in academia and industry, engineers and manufacturers working on OPV design, development and implementation.



Study of the Photostability of Organic Solar Cells

Author : Elena Barulina

Publisher :

Page : 0 pages

File Size : 50,63 MB

Release : 2020

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ISBN :

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Book Description

Despite a strong increase in the electrical conversion efficiencies of organic solar cells, their long-term stability is a key factor for their commercial viability and therefore needs to be examined in detail. The objective here was to study the lifetime of organic solar cells by varying the active materials in the D:A mixture, the cell architecture, the interfacial layers, the treatments applied and the encapsulation process. Regardless of these parameters, a high stability could be obtained for PC71BM-based devices under LED. On the other hand, under AM1.5, a post-annealing process considerably improves the stability of the devices, but the choice of the cell structure remains the key parameter where only cells with normal structure showed a high stability over time. These layers were studied by absorption spectroscopy, AFM, XRD and analytical TEM. PC71BM-based devices can thus serve as a reference in the study of the stability of mixtures based on NFAs (PBDB-T:ITIC and PBDB-T-2F:ITIC-4F). Regardless of the illumination (LED or AM1.5) and the various parameters, NFA-based solar cells are unstable. Under LEDs, ITIC-4F-based solar cells have a better stability than ITIC-based solar cells, but this degradation also depends very strongly on the chemical nature of the electron extraction layer. Flexible encapsulation processes on ink-jet-printed modules from Dracula Technologies have been evaluated. These modules demonstrated relatively stable properties after 1000 hours of continuous illumination by a non-UV-filtered xenon lamp.



Fundamentals of Solar Cell Design

Author : Inamuddin

Publisher : John Wiley & Sons

Page : 578 pages

File Size : 26,90 MB

Release : 2021-08-24

Category : Science

ISBN : 1119724708

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Book Description

Solar cells are semiconductor devices that convert light photons into electricity in photovoltaic energy conversion and can help to overcome the global energy crisis. Solar cells have many applications including remote area power systems, earth-orbiting satellites, wristwatches, water pumping, photodetectors and remote radiotelephones. Solar cell technology is economically feasible for commercial-scale power generation. While commercial solar cells exhibit good performance and stability, still researchers are looking at many ways to improve the performance and cost of solar cells via modulating the fundamental properties of semiconductors. Solar cell technology is the key to a clean energy future. Solar cells directly harvest energy from the sun’s light radiation into electricity are in an ever-growing demand for future global energy production. Solar cell-based energy harvesting has attracted worldwide attention for their notable features, such as cheap renewable technology, scalable, lightweight, flexibility, versatility, no greenhouse gas emission, environment, and economy friendly and operational costs are quite low compared to other forms of power generation. Thus, solar cell technology is at the forefront of renewable energy technologies which are used in telecommunications, power plants, small devices to satellites. Aiming at large-scale implementation can be manipulated by various types used in solar cell design and exploration of new materials towards improving performance and reducing cost. Therefore, in-depth knowledge about solar cell design is fundamental for those who wish to apply this knowledge and understanding in industries and academics. This book provides a comprehensive overview on solar cells and explores the history to evolution and present scenarios of solar cell design, classification, properties, various semiconductor materials, thin films, wafer-scale, transparent solar cells, and so on. It also includes solar cells’ characterization analytical tools, theoretical modeling, practices to enhance conversion efficiencies, applications and patents.