共查询到20条相似文献,搜索用时 15 毫秒
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R. C. I. MacKenzie V. S. Balderrama S. Schmeisser R. Stoof S. Greedy J. Pallarès L. F. Marsal A. Chanaewa E. von Hauff 《Liver Transplantation》2016,6(4)
Performance losses and aging mechanisms are investigated in state‐of‐the‐art PTB7:PC70BM solar cells. Inverted devices incorporating a vanadium pentoxide (V2O5) top contact have efficiencies of 8%. After aging the unencapsulated devices, no changes are observed in the open circuit voltage (Voc) or short circuit current (Jsc); however, the fill factor (FF) drops from 0.7 to 0.61. An s‐shape initially appears in the J–V curve after aging, which can be reduced by cycling through the J–V curve under illumination. This is discussed in context of the redox properties of V2O5. With impedance spectroscopy, it is demonstrated that changes to the contact interfaces are completely reversible and not responsible for the performance loss. Intensity modulated photocurrent spectroscopy combined with device modeling reveals that the loss in FF is due to trap formation in the active layer. Additionally it is observed that the performance of pristine devices is limited by optical absorption in the thin active layer and the build‐up of space charge which hinders carrier extraction. 相似文献
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Chih‐Yu Chang Lijian Zuo Hin‐Lap Yip Chang‐Zhi Li Yongxi Li Chain‐Shu Hsu Yen‐Ju Cheng Hongzheng Chen Alex K‐Y. Jen 《Liver Transplantation》2014,4(7)
Highly efficient tandem and semitransparent (ST) polymer solar cells utilizing the same donor polymer blended with [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM) and [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM) as active layers are demonstrated. A high power conversion efficiency (PCE) of 8.5% and a record high open‐circuit voltage of 1.71 V are achieved for a tandem cell based on a medium bandgap polymer poly(indacenodithiophene‐co‐phananthrene‐quinoxaline) (PIDT‐phanQ). In addition, this approach can also be applied to a low bandgap polymer poly[2,6‐(4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]dithiophene)‐alt‐4,7‐(5‐fluoro‐2,1,3‐benzothia‐diazole)] (PCPDTFBT), and PCEs up to 7.9% are achieved. Due to the very thin total active layer thickness, a highly efficient ST tandem cell based on PIDT‐phanQ exhibits a high PCE of 7.4%, which is the highest value reported to date for a ST solar cell. The ST device also possesses a desirable average visible transmittance (≈40%) and an excellent color rendering index (≈100), permitting its use in power‐generating window applications. 相似文献
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Polymer/small molecule/fullerene based ternary solar cells have made great progress and have attracted considerable attention in recent years. The addition of small molecules can effectively compensate for the disadvantages of polymer solar cells, such as increasing the light‐harvesting ability, providing cascade energy levels, and tuning the morphology. Thus, polymer/small molecule/fullerene based ternary solar cells are promising candidates to obtain further improvements in photovoltaic performance for organic solar cells. This article summarizes the developments of ternary solar cells with small molecules as third components, and represents the possible photo‐physics process in the ternary blends. In addition, the challenges and perspectives for ternary solar cells are discussed. 相似文献
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Chuanfei Wang Xiaofeng Xu Wei Zhang Jonas Bergqvist Yuxin Xia Xiangyi Meng Kim Bini Wei Ma Arkady Yartsev Koen Vandewal Mats R. Andersson Olle Inganäs Mats Fahlman Ergang Wang 《Liver Transplantation》2016,6(18)
One of the factors limiting the performance of organic solar cells (OSCs) is their large energy losses (E loss) in the conversion from photons to electrons, typically believed to be around 0.6 eV and often higher than those of inorganic solar cells. In this work, a novel low band gap polymer PIDTT‐TID with a optical gap of 1.49 eV is synthesized and used as the donor combined with PC71BM in solar cells. These solar cells attain a good power conversion efficiency of 6.7% with a high open‐circuit voltage of 1.0 V, leading to the E loss as low as 0.49 eV. A systematic study indicates that the driving force in this donor and acceptor system is sufficient for charge generation with the low E loss. This work pushes the minimal E loss of OSCs down to 0.49 eV, approaching the values of some inorganic and hybrid solar cells. It indicates the potential for further enhancement of the performance of OSCs by improving their V oc since the E loss can be minimized. 相似文献
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In this study, a wavelength selective semitransparent polymer solar cell (ST‐PSC) with a proper transmission spectrum for plant growth is proposed for greenhouse applications. A ternary strategy combining a wide bandgap polymer donor with a near‐infrared absorbing nonfullerene acceptor and a high electron mobility fullerene acceptor is introduced to achieve PSCs with power conversion efficiency (PCE) over 10%. The addition of PC71BM into J52:IEICO‐4F binary blend contributes to the suppressed trap‐assisted recombination, enhanced charge extraction, and improved open‐circuit voltage simultaneously. ST‐PSC based on the J52:IEICO‐4F:PC71BM ternary blend shows an optimized performance with PCE of 7.75% and a defined crop growth factor of 24.8%. Such high‐performance ST‐PSC is achieved by carefully engineering the absorption spectrum of the light harvesting materials. As a result, the transmission spectra of the semitransparent devices are well‐matched with the absorption spectra of the photoreceptors, such as chlorophylls, in green plants, which provides adequate lighting conditions for photosynthesis and plant growth, and therefore making it a competitive candidate for photovoltaic greenhouse applications. 相似文献
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Dechan Angmo Jorgen Sweelssen Ronn Andriessen Yulia Galagan Frederik C. Krebs 《Liver Transplantation》2013,3(9):1230-1237
Evaporation is the most commonly used deposition method in the processing of back electrodes in polymer solar cells used in scientific studies. However, vacuum‐based methods such as evaporation are uneconomical in the upscaling of polymer solar cells as they are throughput limiting steps in an otherwise fast roll‐to‐roll production line. In this paper, the applicability of inkjet printing in the ambient processing of back electrodes in inverted polymer solar cells with the structure ITO/ZnO/P3HT:PCBM/PEDOT:PSS/Ag is investigated. Furthermore, the limitation of screen printing, the commonly employed method in the ambient processing of back electrode, is demonstrated and discussed. Both inkjet printing and screen printing of back electrodes are studied for their impact on the photovoltaic properties of the polymer solar cells measured under 1000 Wm?2 AM1.5. Each ambient processing technique is compared with evaporation in the processing of back electrode. Laser beam induced current (LBIC) imaging is used to investigate the impact of the processing techniques on the current collection in the devices. We report that inkjet printing of back electrode delivers devices having photovoltaic performance comparable to devices with evaporated back electrodes. We further confirm that inkjet printing represent an efficient alternative to screen printing. 相似文献
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Dario Di Carlo Rasi Koen H. Hendriks Martijn M. Wienk René A. J. Janssen 《Liver Transplantation》2017,7(22)
Triple‐junction device architectures represent a promising strategy to highly efficient organic solar cells. Accurate characterization of such devices is challenging, especially with respect to determining the external quantum efficiency (EQE) of the individual subcells. The specific light bias conditions that are commonly used to determine the EQE of a subcell of interest cause an excess of charge generation in the two other subcells. This results in the build‐up of an electric field over the subcell of interest, which enhances current generation and leads to an overestimation of the EQE. A new protocol, involving optical modeling, is developed to correctly measure the EQE of triple‐junction organic solar cells. Apart from correcting for the build‐up electric field, the effect of light intensity is considered with the help of representative single‐junction cells. The short‐circuit current density (JSC) determined from integration of the EQE with the AM1.5G solar spectrum differs by up to 10% between corrected and uncorrected protocols. The results are validated by comparing the EQE experimentally measured to the EQE calculated via optical‐electronic modeling, obtaining an excellent agreement. 相似文献
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Intrinsic photodegradation of organic solar cells, theoretically attributed to C? H bond rearrangement/breaking, remains a key commercialization barrier. This work presents, via dark electron paramagnetic resonance (EPR), the first experimental evidence for metastable C dangling bonds (DBs) formed by blue/UV irradiation of polymer:fullerene blend films in nitrogen. The DB density increases with irradiation and decreases ≈4‐fold after 2 weeks in the dark. The dark EPR also shows increased densities of other spin‐active sites in photodegraded polymer, fullerene, and polymer:fullerene blend films, consistent with broad electronic measurements of fundamental properties, including defect/gap state densities. The EPR and electronic measurements enable identification of defect states, whether in the polymer, fullerene, or at the donor/acceptor (D/A) interface. Importantly, the EPR results indicate that the DBs are at the D/A interface, as they were present only in the blend films. The role of polarons in interface DB formation is also discussed. 相似文献
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Polymer Solar Cells: Matrix Organization and Merit Factor Evaluation as a Method to Address the Challenge of Finding a Polymer Material for Roll Coated Polymer Solar Cells (Adv. Energy Mater. 10/2015)
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Eva Bundgaard Francesco Livi Ole Hagemann Jon E. Carlé Martin Helgesen Ilona M. Heckler Natalia K. Zawacka Dechan Angmo Thue T. Larsen‐Olsen Gisele A. dos Reis Benatto Bérenger Roth Morten V. Madsen Mats R. Andersson Mikkel Jørgensen Roar R. Søndergaard Frederik C. Krebs 《Liver Transplantation》2015,5(10)
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Solar Cells: Investigation of Charge Carrier Behavior in High Performance Ternary Blend Polymer Solar Cells (Adv. Energy Mater. 19/2016)
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Tack Ho Lee Mohammad Afsar Uddin Chengmei Zhong Seo‐Jin Ko Bright Walker Taehyo Kim Yung Jin Yoon Song Yi Park Alan J. Heeger Han Young Woo Jin Young Kim 《Liver Transplantation》2016,6(19)
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Mapping Nonfullerene Acceptors with a Novel Wide Bandgap Polymer for High Performance Polymer Solar Cells
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Xunfan Liao Zhaoyang Yao Ke Gao Xueliang Shi Lijian Zuo Zonglong Zhu Lie Chen Feng Liu Yiwang Chen Alex K.‐Y. Jen 《Liver Transplantation》2018,8(24)
A new weak electron‐deficient building block, bis(2‐ethylhexyl) 2,5‐bis(5‐bromothiophen‐2‐yl) thieno[3,2‐b]thiophene‐3,6‐dicarboxylate ( TT‐Th ), is incorporated to construct a wide‐bandgap (1.88 eV) polymer PBDT‐TT for nonfullerene polymer solar cells (NF‐PSCs). PBDT‐TT possesses suitable energy levels and complementary absorption when blended with both ITIC analogues ( ITIC and IT‐M ) and a near‐infrared (NIR) acceptor ( 6TIC ). Moreover, PBDT‐TT exhibits good conjugated planarity and preferable face‐on orientation in the blended thin film, which are beneficial for charge transfer and carrier transport. The PSCs based on PBDT‐TT : IT‐M and PBDT‐TT : 6TIC blend films yield high power conversion efficiencies of 11.38% and 11.03%, respectively. To the best of the authors' knowledge, the PCE of 11.03% for PBDT‐TT : 6TIC‐ based device is one of the highest values reported for NIR NF‐PSCs. This work demonstrates that TT‐Th is a useful new electron‐accepting building block for making p‐type wide bandgap polymers for efficient NIR NF‐PSCs. 相似文献
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Zheng Tang Wolfgang Tress Qinye Bao Mohammad J. Jafari Jonas Bergqvist Thomas Ederth Mats R. Andersson Olle Inganäs 《Liver Transplantation》2014,4(15)
The effects of cathode modification by a conjugated polymer interlayer PFPA1 on the performance of reversed organic solar cells (substrate/cathode/active layer/transparent anode) based on different active material systems and different substrate electrodes are systematically investigated. A reduction of the work function irrespective of the substrate cathode used is observed upon the deposition of the PFPA1 interlayer, which is further related to an improved built‐in electric field and open‐circuit voltage. The amphiphilic character of the PFPA1 interlayer alters the surface energy of the substrate cathode, leading to the formation of a better active layer morphology aiding efficient exciton dissociation and photocurrent extraction in the modified solar cells. Hence, internal quantum efficiency is found to be significantly higher than that of their unmodified counterparts, while optically, the modified and unmodified solar cells are identical. Moreover, the deep highest occupied molecular orbital (HOMO) of the PFPA1 interlayer improves the selectivity for all investigated substrate cathodes, thus enhancing the fill factor. 相似文献
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Henrik F. Dam Thomas R. Andersen Emil B. L. Pedersen Karl T. S. Thydén Martin Helgesen Jon E. Carlé Peter S. Jørgensen Juliane Reinhardt Roar R. Søndergaard Mikkel Jørgensen Eva Bundgaard Frederik C. Krebs Jens W. Andreasen 《Liver Transplantation》2015,5(1)
The realization of a complete tandem polymer solar cell under ambient conditions using only printing and coating methods on a flexible substrate results in a fully scalable process but also requires accurate control during layer formation to succeed. The serial process where the layers are added one after the other by wet processing leaves plenty of room for error and the process development calls for an analytical technique that enables 3D reconstruction of the layer stack with the possibility to probe thickness, density, and chemistry of the individual layers in the stack. The use of ptychography on a complete 12‐layer solar cell stack is presented and it is shown that this technique provides the necessary insight to enable efficient development of inks and processes for the most critical layers in the tandem stack such as the recombination layer where solvent penetration in fully solution processed 12‐layer stacks is critical in eleven of the steps. 相似文献