共查询到20条相似文献，搜索用时 15 毫秒
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Zheng Tang Zandra George Zaifei Ma Jonas Bergqvist Kristofer Tvingstedt Koen Vandewal Ergang Wang L. Mattias Andersson Mats R. Andersson Fengling Zhang Olle Inganäs 《Liver Transplantation》2012,2(12):1467-1476
Semi‐transparent (ST) organic solar cells with potential application as power generating windows are studied. The main challenge is to find proper transparent electrodes with desired electrical and optical properties. In this work, this is addressed by employing an amphiphilic conjugated polymer PFPA‐1 modified ITO coated glass substrate as the ohmic electron‐collecting cathode and PEDOT:PSS PH1000 as the hole‐collecting anode. For active layers based on different donor polymers, considerably lower reflection and parasitic absorption are found in the ST solar cells as compared to solar cells in the standard geometry with an ITO/PEDOT:PSS anode and a LiF/Al cathode. The ST solar cells have remarkably high internal quantum efficiency at short circuit condition (～90%) and high transmittance (～50%). Hence, efficient ST tandem solar cells with enhanced power conversion efficiency (PCE) compared to a single ST solar cell can be constructed by connecting the stacked two ST sub‐cells in parallel. The total loss of photons by reflection, parasitic absorption and transmission in the ST tandem solar cell can be smaller than the loss in a standard solar cell based on the same active materials. We demonstrate this by stacking five separately prepared ST cells on top of each other, to obtain a higher photocurrent than in an optimized standard solar cell. 相似文献
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Chin Pang Yau Sarah Wang Neil D. Treat Zhuping Fei Bertrand J. Tremolet de Villers Michael L. Chabinyc Martin Heeney 《Liver Transplantation》2015,5(5)
Dithienogermole‐co‐thieno[3,4‐c]pyrroledione (DTG‐TPD) polymers incorporating chemically cross‐linkable sidechains are reported and their properties compared to a parent polymer with simple octyl sidechains. Two cross‐linking groups and mechanisms are investigated, UV‐promoted radical cross‐linking of an alkyl bromide cross‐linker and acid‐promoted cationic cross‐linking of an oxetane cross‐linker. It is found that random copolymers with a 20% incorporation of the cross‐linker demonstrate a higher performance in bulk heterojunction solar cells than the parent polymer, while 100% cross‐linker incorporation results in deterioration in device efficiency. The use of 1,8‐diiodooctane (DIO) as a processing additive improves as‐cast solar cell performance, but is found to have a significant deleterious impact on solar cell efficiency after UV exposure. The instability to UV can be overcome by the use of an alternative additive, 1‐chloronapthalene, which also promotes high device efficiency. Cross‐linking of the polymer is investigated in the presence and absence of fullerene highlighting significant differences in behavior. Intractable films cannot be obtained by radical cross‐linking in the presence of fullerene, whereas cationic cross‐linking is successful. 相似文献
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Koen H. Hendriks Weiwei Li Martijn M. Wienk René A. J. Janssen 《Liver Transplantation》2013,3(5):674-679
We compare the opto‐electronic and photovoltaic properties of two diketopyrrolopyrrole (DPP) based semiconducting polymers in which the DPP unit alternates along the chain with a conjugated bis(dithienyl)phenylene (4TP) unit. The two polymers differ only in the solubilizing substituents on the thiophene rings which are either alkyl (PDPP4TP) or alkoxy (PDPP4TOP) groups. We show that alkoxy groups lower the optical band gap and increase the ionization potential compared to the alkyl groups. As a result, PDDP4TOP provides a significantly higher charge generation efficiency and concomitant higher short‐circuit current, 18.0 mA cm?2 vs. 12.4 mA cm?2, compared to PDPP4TP in optimized devices with [6,6]phenyl‐C71‐butyric acid methyl ester ([70]PCBM) as acceptor, but a simultaneous decrease in open circuit voltage, 0.51 vs. 0.67 V. The increased current arises from a higher external quantum efficiency and a wider spectral coverage. The net result is a small increase in power conversion efficiency from 5.8% for PDPP4TP to 6.0% for the PDPP4TOP in optimized devices. The optimized processing conditions and bulk heterojunction morphology are virtually identical for both photoactive layers. The study demonstrates that the side chains enable effective method for rationally designing new photoactive semiconducting polymers. 相似文献
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Serkan Esiner Tom Bus Martijn M. Wienk Ko Hermans René A. J. Janssen 《Liver Transplantation》2013,3(8):1013-1017
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Sooncheol Kwon Jin Kuen Park Geunjin Kim Jaemin Kong Guillermo C. Bazan Kwanghee Lee 《Liver Transplantation》2012,2(12):1420-1424
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Sooncheol Kwon Jin Kuen Park Geunjin Kim Jaemin Kong Guillermo C. Bazan Kwanghee Lee 《Liver Transplantation》2012,2(12):1413-1413
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Aurélien Tournebize Pierre‐Olivier Bussière Pascal Wong‐Wah‐Chung Sandrine Thérias Agnès Rivaton Jean‐Luc Gardette Serge Beaupré Mario Leclerc 《Liver Transplantation》2013,3(4):478-487
This paper reports on the photochemical behavior upon exposure to UV‐visible light of a poly(2,7‐carbazole) derivative for use in high‐performance solar cells. Poly[N‐9′‐hepta‐decanyl‐2,7‐carbazole‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole)] (PCDTBT) is one of a relatively large class of push‐pull carbazole‐based copolymers that have been synthesized to better harvest the solar spectrum. The 2,7‐carbazole building block of PCDTBT is also used with different electron‐accepting units in a large variety of low‐band‐gap polymers. The photochemical and morphological behavior of PCDTBT thin films is investigated from the molecular scale to the nanomechanical properties. The photo‐oxidation mechanism is shown to be governed by chain‐scission and cross‐linking reactions. It results in dramatic evolution of the morphology, roughness and stiffness of thin PCDTBT films. Based on the identification of several photoproducts formed along the macromolecular chains or released into the gas phase, the main pathways of PCDTBT photochemical evolution are discussed. These processes first involve the scission of the C–N bond between the carbazole group and the tertiary carbon atom bearing the alkyl side‐chain. Modifications of the chemical structure of PCDTBT, the evolution of its UV‐visible absorbance, and its nanomechanical properties initiated by light irradiation are shown to be closely related. 相似文献
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Bo Zhang Yonggao Yu Jiadong Zhou Zhenfeng Wang Haoran Tang Shenkun Xie Zengqi Xie Liuyong Hu Hin‐Lap Yip Long Ye Harald Ade Zhitian Liu Zhicai He Chunhui Duan Fei Huang Yong Cao 《Liver Transplantation》2020,10(12)
In this contribution, a versatile building block, 3,4‐dicyanothiophene (DCT), which possesses structural simplicity and synthetic accessibility for constructing high‐performance, low‐cost, wide‐bandgap conjugated polymers for use as donors in polymer solar cells (PSCs), is reported. A prototype polymer, PB3TCN‐C66, and its cyano‐free analogue polymer PB3T‐C66, are synthesized to evaluate the potential of using DCT in nonfullerene PSCs. A stronger aggregation property in solution, higher thermal transition temperatures with higher enthalpies, a larger dipole moment, higher relative dielectric constant, and more linear conformation are exhibited by PB3TCN‐C66. Solar cells employing IT‐4F as the electron acceptor offer power conversion efficiencies (PCEs) of 11.2% and 2.3% for PB3TCN‐C66 and PB3T‐C66, respectively. Morphological characterizations reveal that the PB3TCN‐C66:IT‐4F blend exhibits better π–π paracrystallinity, a contracted domain size, and higher phase purity, consistent with its higher molecular interaction parameter, derived from thermodynamic calculations. Moreover, PB3TCN‐C66 offers a higher open‐circuit voltage and reduced energy loss than most state‐of‐the‐art wide‐bandgap polymers, without the need of additional electron‐withdrawing substituents. Two additional polymers derived from DCT also demonstrate promising performance with a higher PCE of 13.4% being achieved. Thus, DCT represents a versatile and promising building block for constructing high‐performance, low‐cost, conjugated polymers for application in PSCs. 相似文献
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Recombination of charges residing in the TiO2 and redox electrolyte is one of the factors affecting the efficiency of dye sensitized solar cells (DSSCs). To circumvent this recombination, inorganic oxide barrier layers and organic silanes have been coated on TiO2/dyes. Due to the insulating nature of these layers, the efficiency increase is not very impressive. Conducting polymers with different band edges are used to suppress the charge recombination. Amongst the four polymers that are used as barrier layers, a polymer with a highest occupied molecular orbital energy at ?5.8 eV and lowest unoccupied molecular orbital at ?3.1 eV is found to increase the electron life time at TiO2 and decrease the charge recombination. The electron life time is found to be 88 ms. In addition to the long electron life time, the recombination resistance of this polymer is also high (91 Ω). This resistance is 18% higher than that measured for DSSCs without polymer barrier layer. These factors impact the efficiency of DSSCs. DSSCs fabricated with this polymer as barrier layer exhibit an efficiency of 9.2%, which is 22% higher than that of DSSCs without polymer barrier layer. 相似文献
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Junyi Wang Shiliang Wang Chunhui Duan Fallon J. M. Colberts Jiangquan Mai Xi Liu Xiao'e Jia Xinhui Lu René A. J. Janssen Fei Huang Yong Cao 《Liver Transplantation》2017,7(22)
To advance polymer solar cells (PSCs) toward real‐world applications, it is crucial to develop materials that are compatible with a low‐cost large‐scale manufacturing technology. In this context, a practically useful polymer should fulfill several critical requirements: the capability to provide high power conversion efficiencies (PCEs) via low‐cost fabrication using environmentally friendly solvents under mild thermal conditions, resulting in an active layer that is thick enough to minimize defects in large‐area films. Here, the development of new photovoltaic polymers is reported through rational molecular design to meet these requirements. Benzodithiophene (BDT)‐difluorobenzoxadiazole (ffBX)‐2‐decyltetradecyl (DT), a wide‐bandgap polymer based on ffBX and BDT emerges as the first example that fulfills the qualifications. When blended with a low‐cost acceptor (C60‐fullerene derivative), BDT‐ffBX‐DT produces a PCE of 9.4% at active layer thickness over 250 nm. BDT‐ffBX‐DT devices can be fabricated from nonhalogenated solvents at low processing temperature. The success of BDT‐ffBX‐DT originates from its appropriate electronic structure and charge transport characteristics, in combination with a favorable face‐on orientation of the polymer backbone in blends, and the ability to form proper phase separation morphology with a fibrillar bicontinuous interpenetrating network in bulk‐heterojunction films. With these characteristics, BDT‐ffBX‐DT represents a meaningful step toward future everyday applications of polymer solar cells. 相似文献
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Ahmed Najari Serge Beaupré Nicolas Allard Mariane Ouattara Jean‐Rémi Pouliot Patrick Charest Simon Besner Martin Simoneau Mario Leclerc 《Liver Transplantation》2015,5(23)
Polymers based on thieno[3,4‐c]pyrrole‐4,6‐dione derivatives are interesting and promising candidates for organic bulk heterojunction solar cells. Herein, a series of push–pull conjugated polymers based on thieno[3,4‐c]pyrrole‐4,6‐dione (TPD), furo[3,4‐c]pyrrole‐4,6‐dione (FPD), and selenopheno[3,4‐c]‐pyrrole‐4,6‐dione (SePD) have been synthesized by direct heteroarylation polymerization and fully characterized. The impacts of both the heteroatom (sulfur, oxygen, and selenium) and the side chain (branched or linear) of [3,4‐c]pyrrole‐4,6‐dione unit on the electro‐optical properties have been investigated. Among polymers developed, two new highly processable terthiophene–SePD ( P4 ) and dithienosilole–SePD ( P9 ) copolymers led to air‐processed polymer solar cells with power conversion efficiencies of 5.1% and 7.1% using the following inverted configuration: ITO/ZnO/Polymer:PCBM/MoO3/Ag. These promising results make P4 and P9 good candidates for further upscaling and device optimization. 相似文献
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Xiaofeng Xu Zhaojun Li Wei Zhang Xiangyi Meng Xianshao Zou Dario Di Carlo Rasi Wei Ma Arkady Yartsev Mats R. Andersson René A. J. Janssen Ergang Wang 《Liver Transplantation》2018,8(1)
In very recent years, growing efforts have been devoted to the development of all‐polymer solar cells (all‐PSCs). One of the advantages of all‐PSCs over the fullerene‐based PSCs is the versatile design of both donor and acceptor polymers which allows the optimization of energy levels to maximize the open‐circuit voltage (Voc). However, there is no successful example of all‐PSCs with both high Voc over 1 V and high power conversion efficiency (PCE) up to 8% reported so far. In this work, a combination of a donor polymer poly[4,8‐bis(5‐(2‐octylthio)thiophen‐2‐yl)benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl‐alt‐(5‐(2‐ethylhexyl)‐4H‐thieno[3,4‐c]pyrrole‐4,6(5H)‐dione)‐1,3‐diyl] (PBDTS‐TPD) with a low‐lying highest occupied molecular orbital level and an acceptor polymer poly[[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐thiophene‐2,5‐diyl] (PNDI‐T) with a high‐lying lowest unoccupied molecular orbital level is used, realizing high‐performance all‐PSCs with simultaneously high Voc of 1.1 V and high PCE of 8.0%, and surpassing the performance of the corresponding PC71BM‐based PSCs. The PBDTS‐TPD:PNDI‐T all‐PSCs achieve a maximum internal quantum efficiency of 95% at 450 nm, which reveals that almost all the absorbed photons can be converted into free charges and collected by electrodes. This work demonstrates the advantages of all‐PSCs by incorporating proper donor and acceptor polymers to boost both Voc and PCEs. 相似文献
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Jaewon Lee Min Kim Boseok Kang Sae Byeok Jo Heung Gyu Kim Jisoo Shin Kilwon Cho 《Liver Transplantation》2014,4(10)
A series of four polymers containing benzo[1,2‐b:4,5‐b′]dithiophene (BDT) and 5,6‐difluoro‐4,7‐diiodobenzo[c][1,2,5]thiadiazole (2FBT), PBDT2FBT, PBDT2FBT‐O, PBDT2FBT‐T, and PBDT2FBT‐T‐O, are synthesized with their four different side chains, alkyl‐, alkoxy‐, alkylthienyl‐, and alkoxythienyl. Experimental results and theoretical calculations show that the molecular tuning of the side chains simultaneously influences the solubilities, energy levels, light absorption, surface tension, and intermolecular packing of the resulting polymers by altering their molecular coplanarity and electron affinity. The polymer solar cell (PSC) based on a blend of PBDT2FBT‐T/[6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM) exhibits the best photovoltaic performance of the four PBDT2FBT derivatives, with a high open‐circuit voltage of 0.98 V and a power conversion efficiency of 6.37%, without any processing additives, post‐treatments, or optical spacers. Furthermore, PBDT2FBT‐T‐O, which has a novel side chain alkoxythienyl, showed promising properties with the most red‐shifted absorption and strong intermolecular packing property in solid state. This study provides insight into molecular design and fabrication strategies via structural tuning of the side chains of conjugated polymers for achieving highly efficient PSCs. 相似文献