共查询到20条相似文献，搜索用时 203 毫秒
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Andreas Distler Tobias Sauermann Hans‐Joachim Egelhaaf Sheila Rodman Dave Waller Kap‐Soo Cheon Mike Lee Dirk M. Guldi 《Liver Transplantation》2014,4(1)
Increasing the lifetime of polymer based organic solar cells is still a major challenge. Here, the photostability of bulk heterojunction solar cells based on the polymer poly[4,4′‐bis(2‐ethylhexyl)dithieno[3,2‐b:2′,3′‐d]silole)‐2,6‐diyl‐alt‐[2,5‐bis(3‐tetradecylthiophen‐2‐yl)thiazole[5,4‐d]thiazole)‐1,8‐diyl] (PDTSTzTz) and the fullerene [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC60BM) under inert atmosphere is investigated. Correlation of electrical measurements on complete devices and UV‐vis absorption measurements as well as high‐performance liquid chromatography (HPLC) analysis on the active materials reveals that photodimerization of PC60BM is responsible for the observed degradation. Simulation of the electrical device parameters shows that this dimerization results in a significant reduction of the charge carrier mobility. Both the dimerization and the associated device performance loss turn out to be reversible upon annealing. BisPC60BM, the bis‐substituted analog of PC60BM, is shown to be resistant towards light exposure, which in turn enables the manufacture of photostable PDTSTzTz:bisPC60BM solar cells. 相似文献
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Suren A. Gevorgyan Nieves Espinosa Laura Ciammaruchi Bérenger Roth Francesco Livi Stylianos Tsopanidis Simon Züfle Sara Queirós Alberto Gregori Gisele Alves dos Reis Benatto Michael Corazza Morten V. Madsen Markus Hösel Michail J. Beliatis Thue Trofod Larsen‐Olsen Francesco Pastorelli António Castro Alba Mingorance Veniero Lenzi Daniel Fluhr Marta Maria Duarte Ramos Achilleas Savva Luís Silvino Alves Marques Ignasi Burgués Efthymios Georgiou Lucia Serrano‐Luján Frederik C. Krebs 《Liver Transplantation》2016,6(22)
The process of accurately gauging lifetime improvements in organic photovoltaics (OPVs) or other similar emerging technologies, such as perovskites solar cells is still a major challenge. The presented work is part of a larger effort of developing a worldwide database of lifetimes that can help establishing reference baselines of stability performance for OPVs and other emerging PV technologies, which can then be utilized for pass‐fail testing standards and predicting tools. The study constitutes scanning of literature articles related to stability data of OPVs, reported until mid‐2015 and collecting the reported data into a database. A generic lifetime marker is utilized for rating the stability of various reported devices. The collected data is combined with an earlier developed and reported database, which was based on articles reported until mid‐2013. The extended database is utilized for establishing the baselines of lifetime for OPVs tested under different conditions. The work also provides the recent progress in stability of unencapsulated OPVs with different architectures, as well as presents the updated diagram of the reported record lifetimes of OPVs. The presented work is another step forward towards the development of pass‐fail testing standards and lifetime prediction tools for emerging PV technologies. 相似文献
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Junwoo Lee Jae Won Kim Sang Ah Park Sung Yun Son Kyoungwon Choi Woojin Lee Minjun Kim Jin Young Kim Taiho Park 《Liver Transplantation》2019,9(34)
This work deals with the investigation of burn‐in loss in ternary blended organic photovoltaics (OPVs) prepared from a UV‐crosslinkable semiconducting polymer (P2FBTT‐Br) and a nonfullerene acceptor (IEICO‐4F) via a green solvent process. The synthesized P2FBTT‐Br can be crosslinked by UV irradiation for 150 s and dissolved in 2‐methylanisole due to its asymmetric structure. In OPV performance and burn‐in loss tests performed at 75 °C or AM 1.5G Sun illumination for 90 h, UV‐crosslinked devices with PC71BM show 9.2% power conversion efficiency (PCE) and better stability against burn‐in loss than pristine devices. The frozen morphology resulting from the crosslinking prevents lateral crystallization and aggregation related to morphological degradation. When IEICO‐4F is introduced in place of a fullerene‐based acceptor, the burn‐in loss due to thermal aging and light soaking is dramatically suppressed because of the frozen morphology and high miscibility of the nonfullerene acceptor (18.7% → 90.8% after 90 h at 75 °C and 37.9% → 77.5% after 90 h at AM 1.5G). The resulting crosslinked device shows 9.4% PCE (9.8% in chlorobenzene), which is the highest value reported to date for crosslinked active materials, in the first green processing approach. 相似文献
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Eric T. Hoke I. T. Sachs‐Quintana Matthew T. Lloyd Isaac Kauvar William R. Mateker Alexandre M. Nardes Craig H. Peters Nikos Kopidakis Michael D. McGehee 《Liver Transplantation》2012,2(11):1351-1357
Understanding the stability and degradation mechanisms of organic solar materials is critically important to achieving long device lifetimes. Here, an investigation of the photodegradation of polymer:fullerene blend films exposed to ambient conditions for a variety of polymer and fullerene derivative combinations is presented. Despite the wide range in polymer stabilities to photodegradation, the rate of irreversible polymer photobleaching in blend films is found to consistently and dramatically increase with decreasing electron affinity of the fullerene derivative. Furthermore, blends containing fullerenes with the smallest electron affinities photobleached at a faster rate than films of the pure polymer. These observations can be explained by a mechanism where both the polymer and fullerene donate photogenerated electrons to diatomic oxygen to form the superoxide radical anion which degrades the polymer. 相似文献
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Solar Cells: Role of Microstructure in Oxygen Induced Photodegradation of Methylammonium Lead Triiodide Perovskite Films (Adv. Energy Mater. 20/2017) 
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下载免费PDF全文 Qing Sun Paul Fassl David Becker‐Koch Alexandra Bausch Boris Rivkin Sai Bai Paul E. Hopkinson Henry J. Snaith Yana Vaynzof 《Liver Transplantation》2017,7(20)
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Qing Sun Paul Fassl David Becker‐Koch Alexandra Bausch Boris Rivkin Sai Bai Paul E. Hopkinson Henry J. Snaith Yana Vaynzof 《Liver Transplantation》2017,7(20)
This paper investigates the impact of microstructure on the degradation rate of methylammonium lead triiodide (MAPbI3) perovskite films upon exposure to light and oxygen. By comparing the oxygen induced degradation of perovskite films of different microstructure–fabricated using either a lead acetate trihydrate precursor or a solvent engineering technique–it is demonstrated that films with larger and more uniform grains and better electronic quality show a significantly reduced degradation compared to films with smaller, more irregular grains. The effect of degradation on the optical, compositional, and microstructural properties of the perovskite layers is characterized and it is demonstrated that oxygen induced degradation is initiated at the layer surface and grain boundaries. It is found that under illumination, irreversible degradation can occur at oxygen levels as low as 1%, suggesting that degradation can commence already during the device fabrication stage. Finally, this work establishes that improved thin‐film microstructure, with large uniform grains and a low density of defects, is a prerequisite for enhanced stability necessary in order to make MAPbI3 a promising long lived and low cost alternative for future photovoltaic applications. 相似文献
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Morten V. Madsen Thomas Tromholt Kion Norrman Frederik C. Krebs 《Liver Transplantation》2013,3(4):424-427
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Suren A. Gevorgyan Morten V. Madsen Bérenger Roth Michael Corazza Markus Hösel Roar R. Søndergaard Mikkel Jørgensen Frederik C. Krebs 《Liver Transplantation》2016,6(2)
The results of a meta‐analysis conducted on organic photovoltaics (OPV) lifetime data reported in the literature is presented through the compilation of an extensive OPV lifetime database based on a large number of articles, followed by analysis of the large body of data. We fully reveal the progress of reported OPV lifetimes. Furthermore, a generic lifetime marker has been defined, which helps with gauging and comparing the performance of different architectures and materials from the perspective of device stability. Based on the analysis, conclusions are drawn on the bottlenecks for stability of device configurations and packaging techniques, as well as the current level of OPV lifetimes reported under different aging conditions. The work is summarized by discussing the development of a tool for OPV lifetime prediction and the development of more stable technologies. An online platform is introduced that will aid the process of generating statistical data on OPV lifetimes and further refinement of the lifetime prediction tool. 相似文献
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Efficient, low‐cost, and low‐embodied energy photovoltaics are key enablers of the global decarbonization agenda. In addition to the market‐leading crystalline silicon technology, several other promising candidates are under active investigation with the perovskites leading the way with single‐junction efficiencies exceeding 25% at the lab‐scale. So‐called organic photovoltaics (solar cells based upon organic semiconductors), particularly those that can be solution processed, have long promised the Nirvana of ultralow cost and very short energy payback times. However, relatively low efficiencies, poor long‐term stability, and issues with manufacturing at scale have so far prevented truly meaningful commercialization of the technology. The recent emergence of the so‐called nonfullerene electron acceptors is potentially about to shift this dynamic—they have delivered a step change in performance in a relatively short period of time. In this Essay, the basic properties of these new materials, their pros and cons, what we know and what we do not know are explored. 相似文献
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Properties of hole transporting layers (HTLs) and back electrode are very critical to the stability of inverted bulk heterojunction organic photovoltaic (OPV) modules. Here, various deposition methods for back electrodes and materials of HTLs are examined by applying to inverted organic solar cells with a structure of indium tin oxide/ZnO/photoactive layer/poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/Ag. The experiment is performed on encapsulated modules with flexible barrier films under accelerated conditions. The OPV modules with screen‐printed Ag electrodes are shown to be electrically unstable with a reduction of the current density under damp heat condition at 85 °C/85% RH. Optical images for the active layer/PEDOT:PSS interface reveal that a reaction between the solvent from the Ag electrode and the underlying layers is the major cause for the degradation. In comparison with materials of the HTLs, the PEDOT:PSS layer shows low stability compared to the MoO3 layer under the accelerated conditions. Unusual chemical changes in the PEDOT:PSS film are observed through X‐ray photoelectron spectroscopy and this is further addressed by correlating the stability of the OPV devices. 相似文献
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Organic solar cells have the potential to become the cheapest form of electricity, beating even silicon photovoltaics. This article summarizes the state of the art in the field, highlighting research challenges, mainly the need for an efficiency increase as well as an improvement in long-term stability. It discusses possible current and future applications, such as building integrated photovoltaics or portable electronics. Finally, the environmental footprint of this renewable energy technology is evaluated, highlighting the potential to be the energy generation technology with the lowest carbon footprint of all. 相似文献
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Lee J. Richter Dean M. DeLongchamp Felicia A. Bokel Sebastian Engmann Kang Wei Chou Aram Amassian Eric Schaible Alexander Hexemer 《Liver Transplantation》2015,5(3)
The most successful active film morphology in organic photovoltaics is the bulk heterojunction (BHJ). The performance of a BHJ arises from a complex interplay of the spatial organization of the segregated donor and acceptor phases and the local order/quality of the respective phases. These critical morphological features develop dynamically during film formation, and it has become common practice to control them by the introduction of processing additives. Here, in situ grazing incidence X‐ray diffraction (GIXD) and grazing incidence small angle X‐ray scattering (GISAXS) studies of the development of order in BHJ films formed from the donor polymer poly(3‐hexylthiophene) and acceptor phenyl‐C61‐butyric acid methyl ester under the influence of two common additives, 1,8‐octanedithiol and 1‐chloronaphthalene, are reported. By comparing optical aggregation to crystallization and using GISAXS to determine the number and nature of phases present during drying, two common mechanisms by which the additives increase P3HT crystallinity are identified. Additives accelerate the appearance of pre‐crystalline nuclei by controlling solvent quality and allow for extended crystal growth by delaying the onset of PCBM‐induced vitrification. The glass transition effects vary system‐to‐system and may be correlated to the number and composition of phases present during drying. 相似文献
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Sofia Masi Aurora Rizzo Rahim Munir Andrea Listorti Antonella Giuri Carola Esposito Corcione Neil D. Treat Giuseppe Gigli Aram Amassian Natalie Stingelin Silvia Colella 《Liver Transplantation》2017,7(14)
Low‐molecular‐weight organic gelators are widely used to influence the solidification of polymers, with applications ranging from packaging items, food containers to organic electronic devices, including organic photovoltaics. Here, this concept is extended to hybrid halide perovskite‐based materials. In situ time‐resolved grazing incidence wide‐angle X‐ray scattering measurements performed during spin coating reveal that organic gelators beneficially influence the nucleation and growth of the perovskite precursor phase. This can be exploited for the fabrication of planar n‐i‐p heterojunction devices with MAPbI3 (MA = CH3NH3+) that display a performance that not only is enhanced by ≈ 25% compared to solar cells where the active layer is produced without the use of a gelator but that also features a higher stability to moisture and a reduced hysteresis. Most importantly, the presented approach is straightforward and simple, and it provides a general method to render the film formation of hybrid perovskites more reliable and robust, analogous to the control that is afforded by these additives in the processing of commodity “plastics.” 相似文献
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