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  • 1. Admassie, Shimelis
    et al.
    Yacob, Zekarias
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Mammo, Wendimagegn
    Yohannes, Teketel
    Solomon, Theodros
    Synthesis, optical and electrochemical characterization of anthrancene and benzothiadiazole-containing polyfluorene copolymers2006In: Bulletin of the Chemical Society of Ethiopia, ISSN 1011-3924, E-ISSN 1726-801X, Vol. 20, no 2, p. 309-317Article in journal (Refereed)
    Abstract [en]

    New solution-processable, anthrancene- and benzothiadiazole-containing polyfluorene copolymers (P1-P3) have been synthesized and characterized. The preparation and characterization of the corresponding blue light-emitting devices are also reported. Polymers P2 and P3 show high photoluminescence efficiency while polymer P2 does not show any significant light emission up to 8.0 V. The results show the need for balance of electron and hole transport in polymer light emitting diodes.

  • 2.
    Admassie, Shimelis
    et al.
    IFM Linköpings universitet.
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Manoj, A.G.
    IFM Linköpings universitet.
    Svensson, Mattias
    Chalmers university of Technology.
    Andersson, Mats R
    Chalmers university of Technology.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    A polymer photodiode using vapour-phase polymerized PEDOT as an anode2005In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 90, p. 133-141Article in journal (Refereed)
    Abstract [en]

      

  • 3.
    Andersson, Lars Mattias
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Bipolar transport observed through extraction currents on organic photovoltaic blend materials2006In: Applied Physics Letters, ISSN 0003-6951, Vol. 89, p. 142111-Article in journal (Refereed)
    Abstract [en]

    Both electron and hole mobilities have been simultaneously measured through charge extraction by linearly increasing voltage on polymer heterojunction solar cells with varying stoichiometry of polymer and acceptor. The polymer is a low band gap copolymer of fluorene, thiophene, and electron accepting groups named APFO-Green 5, and the acceptor is [6,6]-phenyl-C61-butyric acid methylester. Results are correlated to field effect transistor measurements on the same material system. A monotonous increase in mobility for both carrier types is observed with increased acceptor loading.

  • 4.
    Andersson, Lars Mattias
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Stoichiometry, mobility, and performance in bulk heterojunction solar cells2007In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 91, no 7, p. 071108-Article in journal (Refereed)
    Abstract [en]

    Bipolar transport in blends of a copolymer of fluorene, thiophene and electron accepting groups, and the substituted fullerene [6,6]-phenyl-C61-butyric acid methylester have been studied through charge extraction by linearly increasing voltage on solar cells and with field effect transistors. Between 10% and 90% polymer has been used and the results show a clear correlation to solar cell performance. Optimal solar cells comprise 20% polymer and have a power conversion efficiency of 3.5%. The electron mobility is increasing strongly with fullerene content, but is always lower than the hole mobility, thus explaining the low amount of polymer in optimized devices.

  • 5.
    Andersson, Mats R.
    et al.
    Chalmers.
    Lindgren, Lars
    Chalmers.
    Perzon, Erik
    Chalmers.
    Mammo, Wendimagegn
    Chalmers.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    PMSE 413-Solar cells of low band gap conjugated polymers in ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, vol 236, issue , pp 413-PMSE -2008In: ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, AMER CHEMICAL SOC , 2008, Vol. 236, p. 413-Conference paper (Refereed)
    Abstract [en]

    n/a

  • 6.
    Andersson, Mattias
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Mueller, Christian
    Esfera UAB.
    Badada, Bekele H
    University of Cincinnati.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Wuerful, Uli
    Fraunhofer Institute Solar Energy Syst ISE.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Mobility and fill factor correlation in geminate recombination limited solar cells2011In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 110, no 2, p. 024509-Article in journal (Refereed)
    Abstract [en]

    Empirical data for the fill factor as a function of charge carrier mobility for two different polymer: fullerene systems is presented and analyzed. The results indicate that charge extraction depth limitations and space charge effects are inconsistent with the observed behavior, and the decrease in the fill factor is, instead, attributed to the field-dependent charge separation and geminate recombination. A solar cell photocurrent limited by the Onsager-Braun charge transfer exciton dissociation is shown to be able to accommodate the experimental observations. Charge dissociation limited solar cells always benefit from increased mobilities, and the negative contribution from the reduced charge separation is shown to be much more important for the fill factor in these material systems than any adverse effects from charge carrier extraction depth limitations or space charge effects due to unbalanced mobilities. The logarithmic dependence of the fill factor on the mobility for such a process is also shown to imply that simply increasing the mobilities is an impractical way to reach very high fill factors under these conditions since unrealistically high mobilities are required. A more controlled morphology is, instead, argued to be necessary for high performance.

  • 7.
    Bai, Sai
    et al.
    Zhejiang University, Peoples R China .
    Cao, Motao
    Zhejiang University, Peoples R China .
    Jin, Yizheng
    Zhejiang University, Peoples R China Zhejiang University, Peoples R China Zhejiang University, Peoples R China .
    Dai, Xinliang
    Zhejiang University, Peoples R China .
    Liang, Xiaoyong
    Zhejiang University, Peoples R China .
    Ye, Zhizhen
    Zhejiang University, Peoples R China Zhejiang University, Peoples R China .
    Li, Min
    Zhejiang University, Peoples R China .
    Cheng, Jipeng
    Zhejiang University, Peoples R China .
    Xiao, Xuezhang
    Zhejiang University, Peoples R China .
    Wu, Zhongwei
    Soochow University, Peoples R China .
    Xia, Zhouhui
    Soochow University, Peoples R China .
    Sun, Baoquan
    Soochow University, Peoples R China .
    Wang, Ergang
    Chalmers, Sweden .
    Mo, Yueqi
    S China University of Technology, Peoples R China .
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Low-Temperature Combustion-Synthesized Nickel Oxide Thin Films as Hole-Transport Interlayers for SolutionProcessed Optoelectronic Devices2014In: ADVANCED ENERGY MATERIALS, ISSN 1614-6832, Vol. 4, no 6Article in journal (Refereed)
    Abstract [en]

    A method to deposit NiOx thin films by employing combustion reactions is reported and a low processing temperature of 175 °C is demonstrated. The resulting NiOx films exhibit high work functions, excellent optical transparency, and flat surface features. The NiOx thin films are employed as hole-transport interlayers in organic solar cells and polymer light-emitting diodes, exhibiting superior electrical properties

  • 8.
    Bai, Sai
    et al.
    Zhejiang University, Peoples R China.
    He, Shasha
    Zhejiang University, Peoples R China.
    Jin, Yizheng
    Zhejiang University, Peoples R China.
    Wu, Zhongwei
    Soochow University, Peoples R China.
    Xia, Zhouhui
    Soochow University, Peoples R China.
    Sun, Baoquan
    Soochow University, Peoples R China.
    Wang, Xin
    Zhejiang University, Peoples R China.
    Ye, Zhizhen
    Zhejiang University, Peoples R China.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Shao, Shuyan
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Electrophoretic deposited oxide thin films as charge transporting interlayers for solution-processed optoelectronic devices: the case of ZnO nanocrystals2015In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, no 11, p. 8216-8222Article in journal (Refereed)
    Abstract [en]

    A promising fabrication method of electron transporting interlayers for solution-processed optoelectronic devices by electrophoretic deposition (EPD) of colloidal zinc oxide (ZnO) nanocrystals was demonstrated. A low voltage of 3-5 V and a short deposition time of 40 s at room temperature were found to be sufficient to generate dense and uniform ZnO thin films. The EPD ZnO nanocrystal films were applied as ETLs for inverted organic solar cell and polymer light emitting diodes (PLEDs). By optimizing the EPD processing of ZnO nanocrystal electron transporting layers (ETLs), inverted organic solar cells based on [3,4-b]-thiophene/benzodithiophene (PTB7): [6-6]-phenyl-C71-butyric acid methyl ester (PC71BM) and poly(3-hexylthiophene) (P3HT): [6-6]-phenyl-C-61-butyric acid methyl ester (PC61BM) with an average PCE of 8.4% and 4.0% were fabricated. In combination with the PLEDs and flexible devices results, we conclude that the EPD processed ZnOnanocrystal thin films can serve as high quality ETLs for solution-processed optoelectronic devices.

  • 9.
    Bai, Sai
    et al.
    Zhejiang University, Peoples R China; Zhejiang University, Peoples R China.
    Jin, Yizheng
    Zhejiang University, Peoples R China; Zhejiang University, Peoples R China.
    Liang, Xiaoyong
    Zhejiang University, Peoples R China; Zhejiang University, Peoples R China.
    Ye, Zhizhen
    Zhejiang University, Peoples R China; Zhejiang University, Peoples R China.
    Wu, Zhongwei
    Soochow University, Peoples R China.
    Sun, Baoquan
    Soochow University, Peoples R China.
    Ma, Zaifei
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Tang, Zheng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Wang, Jianpu
    Nanjing Technical University, Peoples R China.
    Wuerfel, Uli
    Fraunhofer Institute Solar Energy Syst ISE, Germany; University of Freiburg, Germany.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Ethanedithiol Treatment of Solution-Processed ZnO Thin Films: Controlling the Intragap States of Electron Transporting Interlayers for Efficient and Stable Inverted Organic Photovoltaics2015In: ADVANCED ENERGY MATERIALS, ISSN 1614-6832, Vol. 5, no 5, p. 1401606-Article in journal (Refereed)
    Abstract [en]

    The surface defects of solution-processed ZnO films lead to various intragap states. When the solution-processed ZnO films are used as electron transport interlayers (ETLs) in inverted organic solar cells, the intragap states act as interfacial recombination centers for photogenerated charges and thereby degrade the device performance. Here, a simple passivation method based on ethanedithiol (EDT) treatment is demonstrated, which effectively removes the surface defects of the ZnO nanocrystal films by forming zinc ethanedithiolates. The passivation by EDT treatment modulates the intragap states of the ZnO films and introduces a new intragap band. When the EDT-treated ZnO nanocrystal films are used as ETLs in inverted organic solar cells, both the power conversion efficiency and stability of the devices are improved. The control studies show that the solar cells with EDT-treated ZnO films exhibit reduced charge recombination rates and enhanced charge extraction properties. These features are consistent with the fact that the modulation of the intragap states results in reduction of interfacial recombination as well as the improved charge selectivity and electron transport properties of the ETLs. It is further demonstrated that the EDT treatment-based passivation method can be extended to ZnO films deposited from sol-gel precursors.

  • 10.
    Barrau, Sophie
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Andersson, Viktor
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Masich, Sergej
    Karolinska Institutet, Stockholm.
    Bijleveld, Johan
    Chalmers University of Technology, Göteborg.
    Andersson, Mats R
    Chalmers University of Technology, Göteborg.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Nanomorphology of Bulk Heterojunction Organic Solar Cells in 2D and 3D Correlated to Photovoltaic Performance2009In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 42, no 13, p. 4646-4650Article in journal (Refereed)
    Abstract [en]

    Control of the nanoscale morphology of the donor-acceptor material blends inorganic solar Cells is critical for optimizing the photovoltaic performances. The influence of intrinsic (acceptor materials) and extrinsic (donor:acceptor weight ratio, substrate, solvent) parameters was investigated, by atomic force microscopy (AFM) and electron tomography (ET), on the nanoscale phase separation of blends of a low-band-gap alternating polyfluorene copolymers (APFO-Green9) with [6,6]-phenyl-C-71-butyric acid methyl ester ([70]PCBM). The photovoltaic performances display an optimal efficiency for the device elaborated with a 1:3 APFO-Green polymer:[70][PCBM weight ratio and spin-coated from chloroform solution. The associated active layer morphology presents small phase-separated domains which is a good balance between as a large interfacial donor-acceptor area and Continuous paths of the donor and acceptor phases to the electrodes.

  • 11.
    Barrau, Sophie
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Herland, Anna
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Mammo, W.
    Chalmers University of Technology.
    Andersson, Mats R.
    Chalmers University of Technology.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Integration of Amyloid Nanowires in Organic Solar Cells2008In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 93, p. 23307-Article in journal (Refereed)
    Abstract [en]

      

  • 12.
    Bi, Zhaozhao
    et al.
    Xi An Jiao Tong Univ, Peoples R China.
    Naveed, Hafiz Bilal
    Xi An Jiao Tong Univ, Peoples R China.
    Sui, Xinyu
    CAS Ctr Excellence Nanosci, Peoples R China.
    Zhu, Qinglian
    Xi An Jiao Tong Univ, Peoples R China.
    Xu, Xianbin
    Xi An Jiao Tong Univ, Peoples R China.
    Gou, Lu
    Xi An Jiao Tong Univ, Peoples R China.
    Liu, Yanfeng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhou, Ke
    Xi An Jiao Tong Univ, Peoples R China.
    Zhang, Lei
    Xi An Jiao Tong Univ, Peoples R China.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Liu, Xinfeng
    CAS Ctr Excellence Nanosci, Peoples R China.
    Ma, Wei
    Xi An Jiao Tong Univ, Peoples R China.
    Individual nanostructure optimization in donor and acceptor phases to achieve efficient quaternary organic solar cells2019In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 66, article id 104176Article in journal (Refereed)
    Abstract [en]

    Fullerene derivative (PC71BM) and high crystallinity molecule (DR3TBDTT) are employed into PTB7-Th:FOIC based organic solar cells (OSCs) to cooperate an individual nanostructure optimized quaternary blend. PC71BM functions as molecular adjuster and phase modifier promoting FOIC forming "head-to-head" molecular packing and neutralizing the excessive FOIC crystallites. A multi-scale modified morphology is present thanks to the mixture of FOIC and PC71BM while DR3TBDTT disperses into PTB7-Th matrix to reinforce donors crystal-linity and enhance domain purity. Morphology characterization highlights the importance of individually optimizated nanostructures for donor and acceptor, which contributes to efficient hole and electron transport toward improved carrier mobilities and suppressed non-geminated recombination. Therefore, a power conversion efficiency of 13.51% is realized for a quaternary device which is 16% higher than the binary device (PTB7-Th:FOIC). This work demonstrates that utilizing quaternary strategy for simultaneous optimization of donor and acceptor phases is a feasible way to realize high efficient OSCs.

  • 13.
    Bjorstrom, Cecilia M.
    et al.
    Karlstad University.
    Nilsson, Svante
    Karlstad University.
    Magnusson, Kjell O.
    Karlstad University.
    Moons, Ellen
    Karlstad University.
    Bernasik, Andrzej
    AGH-Univ. of Science and Technology .
    Rysz, Jakub
    Jagiellonian Univ.
    Budkowski, Andrzej
    Jagiellonian Univ.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Andersson, Mats R.
    Chalmers.
    Influence of solvents and substrates on the morphology and the performance of low-bandgap polyfluorene: PCBM photovoltaic devices - art. no. 61921X2006In: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6192, p. X1921-X1921Article in journal (Refereed)
    Abstract [en]

    Spin-coated thin films of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)] (APFO-3) blended with [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) are used as the active material in polymer photovoltaic cells. Such blends are known for their tendency to phase separate during film formation. Tuning the morphology of the blend in a controlled way is one possible road towards higher efficiency. We studied the effect of adding chlorobenzene to chloroform-based blend solutions before spin-coating on the conversion efficiency of APFO-3:PCBM photodiodes, and related that to the lateral and vertical morphology of thin films of the blend. The lateral morphology is imaged by atomic force microscopy (AFM) and the vertical compositional profile is obtained by dynamic secondary ion mass spectrometry (SIMS). The profiles reveal compositional variations consisting of multilayers of alternating polymer-rich and PCBM-rich domains in the blend film spin-coated from chloroform. The vertical compositional variations are caused by surface-directed spinodal waves and are frozen in during the rapid evaporation of a highly volatile solvent. With addition of the low-vapour pressure solvent chlorobenzene, a more homogeneous vertical composition is found. The conversion efficiency for solar cells of this blend was found to be optimal for chloroform: chlorobenzene mixtures with a volume-ratio of 80:1. We have also investigated the role of the substrate on the morphology. We found that blend films spin-coated from chloroform solutions on PEDOT:PSS-coated ITO show a similar compositional structure as the films on silicon, and that changing the substrate from silicon to gold only affects the vertical phase separation in a region close to the substrate interface.

  • 14.
    Bjorstrom Svanstrom, Cecilia M
    et al.
    Karlstad University, Department Phys and Elect Engn, S-65188 Karlstad, Sweden .
    Rysz, Jakub
    Jagiellonian University, Institute Phys, PL-30059 Krakow, Poland .
    Bernasik, Andrzej
    AGH University Science and Technology, Fac Phys and Appl Comp Science, PL-30059 Krakow, Poland .
    Budkowski, Andrzej
    Jagiellonian University, Institute Phys, PL-30059 Krakow, Poland .
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Andersson, Mats R
    Chalmers, Department Polymer Technology, S-41296 Gothenburg, Sweden .
    O Magnusson, Kjell
    Karlstad University, Department Phys and Elect Engn, S-65188 Karlstad, Sweden .
    J Benson-Smith, Jessica
    University London Imperial Coll Science Technology and Med, Department Phys, London SW7 2BW, England .
    Nelson, Jenny
    University London Imperial Coll Science Technology and Med, Department Phys, London SW7 2BW, England .
    Moons, Ellen
    Karlstad University, Department Phys and Elect Engn, S-65188 Karlstad, Sweden .
    Device Performance of APFO-3/PCBM Solar Cells with Controlled Morphology2009In: ADVANCED MATERIALS, ISSN 0935-9648, Vol. 21, no 43, p. 4398-+Article in journal (Refereed)
    Abstract [en]

    Polymer/fullerene solar cells with three different device structures: A) diffuse bilayer, B) spontaneously formed multilayer and C) vertically homogeneous thin films, are fabricated. The photocurrent/voltage performance is compared and it is found that the self-stratified structure (B) yields the highest energy conversion efficiency.

  • 15.
    Cai, Tianqi
    et al.
    Chalmers.
    Zhou, Yi
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Wang, Ergang
    Chalmers.
    Hellstrom, Stefan
    Chalmers.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Xu, Shiai
    East China University of Science and Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Andersson, Mats R
    Chalmers.
    Low bandgap polymers synthesized by FeCol(3) oxidative polymerization2010In: SOLAR ENERGY MATERIALS AND SOLAR CELLS, ISSN 0927-0248, Vol. 94, no 7, p. 1275-1281Article in journal (Refereed)
    Abstract [en]

    Four low bandgap polymers, combining an alkyl thiophene donor with benzo[c][1,2,5]thiadiazole, 2,3-diphenylquinoxaline, 2,3-diphenylthieno[3,4-b]pyrazine and 6,7-diphenyl-[1,2,5]thiadiazolo[3,4-g] quinoxaline acceptors in a donor-acceptor-donor architecture, were synthesized via FeCl3 oxidative polymerization. The molecular weights of the polymers were improved by introducing o-dichlor-obenzene (ODCB) as the reaction solvent instead of the commonly used solvent, chloroform. The photophysical, electrochemical and photovoltaic properties of the resulting polymers were investigated and compared. The optical bandgaps of the polymers vary between 1.0 and 1.9 eV, which is promising for solar cells. The devices spin-coated from an ODCB solution of P1DB:[70]PCBM showed a power conversion efficiency of 1.08% with an open-circuit voltage of 0.91 V and a short-circuit current density of 3.36 mA cm(-2) under irradiation from an AM1.5G solar simulator (100 mW cm(-2)).

  • 16.
    Chen, Youchun
    et al.
    Jilin University, Peoples R China.
    Wang, Shan
    Jilin University, Peoples R China.
    Xue, Lingwei
    Chinese Academic Science, Peoples R China.
    Zhang, Zhiguo
    Chinese Academic Science, Peoples R China.
    Li, Haolong
    Jilin University, Peoples R China.
    Wu, Lixin
    Jilin University, Peoples R China.
    Wang, Yue
    Jilin University, Peoples R China.
    Li, Fenghong
    Jilin University, Peoples R China.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Li, Yongfang
    Chinese Academic Science, Peoples R China.
    Insights into the working mechanism of cathode interlayers in polymer solar cells via [(C8H17)(4)N](4)[SiW12O40]2016In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 48, p. 19189-19196Article in journal (Refereed)
    Abstract [en]

    A low-cost (amp;lt;$1 per g), high-yield (amp;gt;90%), alcohol soluble surfactant-encapsulated polyoxometalate complex [(C8H17)(4)N](4)[SiW12O40] has been synthesized and utilized as a cathode interlayer (CIL) in polymer solar cells (PSCs). A power conversion efficiency of 10.1% can be obtained for PSCs based on PTB7-Th (poly[[2,6-4,8-di(5-ethylhexylthienyl) benzo[1,2-b;3,3-b]-dithiophene][3-fluoro-2[(2-ethylhexyl) carbonyl] thieno [3,4-b]-thiophenediyl]]):PC71BM ([6,6]-phenyl C71-butyric acidmethyl ester) due to the incorporation of [(C8H17)(4)N](4)[SiW12O40]. Combined measurements of current density-voltage characteristics, transient photocurrent, charge carrier mobility and capacitance-voltage characteristics demonstrate that [(C8H17)(4)N](4)[SiW12O40] can effectively increase the built-in potential, charge carrier density and mobility and accelerate the charge carrier extraction in PSCs. Most importantly, the mechanism of using [(C8H17)(4)N](4)[SiW12O40] as the CIL is further brought to light by X-ray photoemission spectroscopy (XPS) and ultraviolet photoemission spectroscopy (UPS) of the metal/ [(C8H17)(4)N](4)[SiW12O40] interface. The findings suggest that [(C8H17)(4)N](4)[SiW12O40] not only decreased the work function of the metal cathodes but also was n-doped upon contact with the metals, which provide insights into the working mechanism of the CILs simultaneously improving the open circuit voltage, short circuit current and fill factor in the PSCs.

  • 17. De, S.
    et al.
    Pascher, T.
    Maiti, M.
    Kesti, T.
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics.
    Yartsev, A.
    Sundstrom, V.
    Geminate charge recombination in alternating polyfluorene copolymer/fullerene blends2007In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 129, no 27, p. 8466-8472Article in journal (Refereed)
    Abstract [en]

    By measuring excited state and charge dynamics in blends of an alternating polyfluorene copolymer and fullerene derivative over nine orders in time and two orders in light intensity, we have monitored the light-induced processes from ultrafast charge photogeneration to much slower decay of charges by recombination. We find that at low light intensities relevant to solar cell operation relatively fast (∼30 ns) geminate recombination is the dominating charge decay process, while nongeminate recombination has a negligible contribution. The conclusion of our work is that under solar illumination conditions geminate recombination of charges may be directly competing with efficient charge collection in polymer/fullerene solar cells. © 2007 American Chemical Society.

  • 18.
    De, Swati
    et al.
    Kemisk Fysik, Kemicentrum, Lunds Universitet, Lund, Sweden.
    Kesti, Tero
    Kemisk Fysik, Kemicentrum, Lunds Universitet, Lund, Sweden.
    Maiti, Manisankar
    Kemisk Fysik, Kemicentrum, Lunds Universitet, Lund, Sweden.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Yartsev, Arkady
    Kemisk Fysik, Kemicentrum, Lunds Universitet, Lund, Sweden.
    Pascher, Torbjörn
    Kemisk Fysik, Kemicentrum, Lunds Universitet, Lund, Sweden.
    Sundström, Villy
    Kemisk Fysik, Kemicentrum, Lunds Universitet, Lund, Sweden.
    Exciton Dynamics in Alternating Polyfluorene/Fullerene Blends2008In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 350, no 1-3, p. 14-22Article in journal (Refereed)
    Abstract [en]

    Exciton dynamics in alternating copolymer/fullerene solar cell blends have been investigated using femtosecond transient absorption spectroscopy. The acceptor concentrations have been varied over a wide range. Experimental data, kinetic modeling and simulations, all indicate that the efficiency of exciton conversion to charges is 100% even at acceptor concentrations as low as 20 wt%. The reported dependence of solar cell efficiency on fullerene concentration may thus arise from other factors. However, there exists an acceptor concentration threshold (5 wt%) below which a substantial fraction of the excitations remain unquenched. The results, we believe are very relevant to optimization of performance efficiency by clever manipulation of morphology. We have also observed exciton–exciton energy transfer in these blends at low acceptor concentrations.

  • 19.
    Du, Chun
    et al.
    Chinese Academy of Science.
    Li, Cuihong
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Li, Weiwei
    Chinese Academy of Science.
    Chen, Xiong
    Chinese Academy of Science.
    Bo, Zhishan
    Beijing Normal University.
    Veit, Clemens
    Fraunhofer Institute for Solar Energy Systems ISE.
    Ma, Zaifei
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Wuerfel, Uli
    Fraunhofer Institute for Solar Energy Systems ISE.
    Zhu, Hongfei
    Chinese Academy of Science.
    Hu, Wenping
    Chinese Academy of Science.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    9-Alkylidene-9H-Fluorene-Containing Polymer for High-Efficiency Polymer Solar Cells2011In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 44, no 19, p. 7617-7624Article in journal (Refereed)
    Abstract [en]

    A novel donor-acceptor copolymer containing 9-alkylidene-9H-fluorene unit in the main chain, poly[9-(1-hexylheptylidene)-2,7-fluorene-alt-5, 5-(4,7-di-2-thienyl-5,6-dialkoxy-2,1,3-benzothiadiazole)] (PAFDTBT), has been synthesized and evaluated in bulk heterojunction polymer solar cells (BHJ PSCs). The polymer possesses a low band gap of 1.84 eV, a low-lying HOMO energy level (5.32 eV), and excellent solubility in common organic solvents. PSCs based on PAFDTBT and (6,6)-phenyl-C(71)-butyric add methyl ester (PC(71)BM) demonstrate a power conversion efficiency (PCE) of 6.2% with a high fill factor (FF) of 0.70, which indicates that 9-alkylidene-9H-fluorene can be a very useful building block for constructing narrow band gap conjugated polymers for high-efficiency BHJ PSCs.

  • 20.
    Dyer, Aubrey L.
    et al.
    Georgia Institute Technology, GA 30332 USA .
    Bulloch, Rayford H.
    Georgia Institute Technology, GA 30332 USA .
    Zhou, Yinhua
    Georgia Institute Technology, GA 30332 USA Huazhong University of Science and Technology, Peoples R China .
    Kippelen, Bernard
    Georgia Institute Technology, GA 30332 USA .
    Reynolds, John R.
    Georgia Institute Technology, GA 30332 USA Georgia Institute Technology, GA 30332 USA .
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    A Vertically Integrated Solar-Powered Electrochromic Window for Energy Efficient Buildings2014In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 26, no 28, p. 4895-4900Article in journal (Refereed)
    Abstract [en]

    A solution-processed self-powered polymer electrochromic/photovoltaic (EC/PV) device is realized by vertically integrating two transparent PV cells with an ECD. The EC/PV cell is a net energy positive dual functional device, which can be reversibly switched between transparent and colored states by PV cells for regulating incoming sunlight through windows. The two PV cells can individually, or in pairs, generate electricity.

  • 21.
    Feng, Guitao
    et al.
    Chinese Academic Science, Peoples R China; University of Chinese Academic Science, Peoples R China.
    Li, Junyu
    DSM DMSC RandD Solut, Netherlands.
    Colberts, Fallon J. M.
    Eindhoven University of Technology, Netherlands.
    Li, Mengmeng
    Eindhoven University of Technology, Netherlands; Eindhoven University of Technology, Netherlands.
    Zhang, Jianqi
    National Centre Nanosci and Technology, Peoples R China.
    Yang, Fan
    Chinese Academic Science, Peoples R China; University of Chinese Academic Science, Peoples R China.
    Jin, Yingzhi
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Janssen, Rene A. J.
    Eindhoven University of Technology, Netherlands; Eindhoven University of Technology, Netherlands.
    Li, Cheng
    Chinese Academic Science, Peoples R China.
    Li, Weiwei
    Chinese Academic Science, Peoples R China.
    “Double-Cable” Conjugated Polymers with Linear Backbone toward High Quantum Efficiencies in Single-Component Polymer Solar Cells2017In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 139, no 51, p. 18647-18656Article in journal (Refereed)
    Abstract [en]

    A series of "double-cable" conjugated polymers were developed for application in efficient single-component polymer solar cells, in which high quantum efficiencies could be achieved due to the optimized nanophase separation between donor and acceptor parts. The new double-cable polymers contain electron-donating poly(benzodithiophene) (BDT) as linear conjugated backbone for hole transport and pendant electron-deficient perylene bisimide (PBI) units for electron transport, connected via a dodecyl linker. Sulfur and fluorine substituents were introduced to tune the energy levels and crystallinity of the conjugated polymers. The double-cable polymers adopt a "face-on" orientation in which the conjugated BDT backbone and the pendant PBI units have a preferential pi-pi stacking direction perpendicular to the substrate, favorable for interchain charge transport normal to the plane. The linear conjugated backbone acts as a scaffold for the crystallization of the PBI groups, to provide a double-cable nanophase separation of donor and acceptor phases. The optimized nanophase separation enables efficient exciton dissociation as well as charge transport as evidenced from the high-up to 80%-internal quantum efficiency for photon-to-electron conversion. In single-component organic solar cells, the double-cable polymers provide power conversion efficiency up to 4.18%. This is one of the highest performances in single-component organic solar cells. The nanophase-separated design can likely be used to achieve high-performance single-component organic solar cells.

  • 22.
    Gadisa, Abay
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Mammo, W.
    Addis Ababa University.
    Andersson, Mattias
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Admassie, S.
    Addis Ababa University.
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Andersson, M.R.
    Chalmers University of Technology.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    A New Donor-Acceptor-Donor Polyfluorence Copolymer with Balanced Electron and Hole Mobility2007In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 0000, no 00Article in journal (Refereed)
  • 23.
    Gadisa, Abay
    et al.
    Hasselt University.
    Tvingstedt, Kristofer
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Vandewal, Koen
    Hasselt University.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    V Manca, Jean
    Hasselt University.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Bipolar Charge Transport in Fullerene Molecules in a Bilayer and Blend of Polyfluorene Copolymer and Fullerene2010In: ADVANCED MATERIALS, ISSN 0935-9648, Vol. 22, no 9, p. 1008-Article in journal (Refereed)
    Abstract [en]

    Efficient polymer solar cells typically contain the fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), which promotes dissociation of excited states and enhances charge transport. The ability of PCBM to transport holes in solar cell bulk heterojunction films is monitored via the electroluminescence emission of a bulk heterojunction blend of PCBM and a polyfluorene copolymer. In polymer/fullerene bilayer diodes, fullerene emission is also observed.

  • 24.
    Gadisa, Abay
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Sharma, Deepak
    Department of Electrical Engineering, Indian Institute of Technology Kanpur, Kanpur, India.
    Svensson, Mattias
    Department of Organic Chemistry and Polymer Technology, Chalmers University of Technology, Göteborg, Sweden.
    Andersson, Mats R.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Improvements of fill factor in solar cells based on blends of polyfluorene copolymers as electron donors2007In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 515, no 5, p. 3126-3131Article in journal (Refereed)
    Abstract [en]

    The photovoltaic characteristics of solar cells based on alternating polyfluorene copolymers, poly(2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)) (APFO-3), and poly(2,7-(9,9-didodecyl-fluorene)-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)) (APFO-4), blended with an electron acceptor fullerene molecule [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), have been investigated and compared. The two copolymers have the same aromatic backbone structure but differ by the length of their alkyl side chain. The overall photovoltaic performance of the solar cells is comparable irrespective of the copolymer used in the active layer. However, the fill factor (FF) values of the devices are strongly affected by the copolymer type. Higher FF values were realized in solar cells with APFO-4 (with longer alkyl side chain)/PCBM bulk heterojunction active layer. On the other hand, devices with blends of APFO-3/APFO-4/PCBM were found to render fill factor values that are intermediate between the values obtained in solar cells with APFO-3/PCBM and APFO-4/PCBM active film. Upon using APFO-3/APFO-4 blends as electron donors, the cell efficiency can be enhanced by about 16% as compared to cells with either APFO-3 or APFO-4. The transport of holes in each polymer obeys the model of hopping transport in disordered media. However, the degree of energetic barrier against hopping was found to be larger in APFO-3. The tuning of the photovoltaic parameters will be discussed based on studies of hole transport in the pure polymer films, and morphology of blend layers. The effect of bipolar transport in PCBM will also be discussed.

  • 25.
    Gedefaw, Desta A.
    et al.
    Chalmers, Sweden.
    Ma, Zaifei
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Henriksson, Patrik
    Chalmers, Sweden.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Andersson, Mats R.
    Chalmers, Sweden.
    Mammo, Wendimagegn
    University of Addis Ababa, Ethiopia.
    RANDOM POLYFLUORENE CO-POLYMERS DESIGNED FOR A BETTER OPTICAL ABSORPTION COVERAGE OF THE VISIBLE REGION OF THE ELECTROMAGNETIC SPECTRUM2014In: Bulletin of the Chemical Society of Ethiopia, ISSN 1011-3924, E-ISSN 1726-801X, Vol. 28, no 1, p. 121-130Article in journal (Refereed)
    Abstract [en]

    Two alternating polyfluorenes (APFO15-F8BT and APFO3-F8BT) with full absorption of the visible region of the electromagnetic radiation were designed and synthesized for bulk-heterojunction solar cell devices. The optical and electrochemical properties of the two polymers were studied. The two polymers exhibited strong absorption in the visible region with no significant valley over the visible region extending up to 650 nm. Deep HOMO and ideally situated LUMO energy levels were the characteristics of the two polymers as revealed from the square wave voltammogram study: desired properties for extracting high open circuit voltage and for a facile charge transfer to the acceptor component in devices to take place, respectively. Photovoltaic devices were fabricated by blending the two polymers with PCBM[70] and up to similar to 2% power conversion efficiency were obtained.

  • 26.
    Gedefaw, Desta A
    et al.
    Chalmers, Sweden .
    Zhou, Yi
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Ma, Zaifei
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Genene, Zewdneh
    University of Addis Ababa, Ethiopia .
    Hellstrom, Stefan
    Chalmers, Sweden .
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Mammo, Wendimagegn
    University of Addis Ababa, Ethiopia .
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Andersson, Mats R
    Chalmers, Sweden .
    Conjugated polymers with polar side chains in bulk heterojunction solar cell devices2014In: Polymer international, ISSN 0959-8103, E-ISSN 1097-0126, Vol. 63, no 1, p. 22-30Article in journal (Refereed)
    Abstract [en]

    Two polymers with polar side chains, namely poly[2,7-(9,9-dioctylfluorene)-alt-5,5-(5,8-di-2-thienyl-(2,3-bis(3-(2-(2-methoxyethoxy)ethoxy)phenyl)quinoxaline))] (P1) and poly[2,7-(9,9-bis(2-(2-methoxyethoxy)ethyl)fluorene)-alt-5,5-(5,8-di-2-thienyl-(2,3-bis(3-(2-(2-methoxyethoxy)-ethoxy)phenyl)quinoxaline))] (P2), were synthesized for solar cell application. A series of bulk heterojunction solar cells were systematically fabricated and characterized by varying the electron-acceptor materials, processing solvents and thickness of the active layer. The results show that P1, with a higher molecular weight and good film-forming properties, performed better. The best device showed an open circuit voltage of 0.87 V, a short circuit current of 6.81 mA cm(-2) and a power conversion efficiency of 2.74% with 1:4 polymer:[6,6]-phenyl-C71-butyric acid methyl ester (PCBM[70]) mixture using o-dichlorobenzene (o-DCB) as processing solvent. P2 on the other hand showed a poorer performance with chlorobenzene as processing solvent, but a much improved performance was obtained using o-DCB instead. Thus, an open circuit voltage of 0.80 V, short circuit current of 6.21 mA cm(-2) and an overall power conversion efficiency of 2.22% were recorded for a polymer:PCBM[70] mixing ratio of 1:4. This is presumably due to the improvement of the morphology of the active layer using o-DCB as processing solvent.

  • 27.
    Gedefaw, Desta
    et al.
    Chalmers, Sweden; University of S Australia, Australia.
    Zaifei, Zaifei
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Mulugeta, Endale
    University of Addis Ababa, Ethiopia.
    Zhao, Yang
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Andersson, Mats R.
    Chalmers, Sweden; University of S Australia, Australia.
    Mammo, Wendimagegn
    University of Addis Ababa, Ethiopia.
    An alternating copolymer of fluorene donor and quinoxaline acceptor versus a terpolymer consisting of fluorene, quinoxaline and benzothiadiazole building units: synthesis and characterization2016In: Polymer Bulletin, ISSN 0170-0839, E-ISSN 1436-2449, Vol. 73, no 4, p. 1167-1183Article in journal (Refereed)
    Abstract [en]

    An alternating polyfluorene copolymer based on fluorene donor and quinoxaline acceptor (P1) and an alternating terpolymer (P2) with fluorene (50 %) donor and quinoxaline (25 %) and benzothiadiazole (25 %) acceptor units were designed and synthesized for use as photoactive materials in solar cells. The presence of benzothiadiazole unit in P2 increased the optical absorption coverage in the range of 350-600 nm, which is an interesting property and a big potential for achieving improved photovoltaic performances with judicious optimization of the devices. Solar cells were fabricated from 1:4 blends of polymers-PCBM[70] using o-dichlorobenzene (o-DCB) as processing solvent, and P1 showed a power conversion efficiency (PCE) of 3.18 %, with a short-circuit current density (J (SC)) of 7.78 mA/cm(2), an open-circuit voltage (V (OC)) of 0.82 V, and a fill factor (FF) of 50 % while P2 showed an overall PCE of 2.14 % with corresponding J (SC) of 5.97 mA/cm(2), V (OC) of 0.84 V and FF of 42 %. In general, P2 gave lower J (SC) and FF presumably due to the fine domain sizes of the polymer-PCBM[70] blend as seen from the atomic force microscopy (AFM) image which might have affected the charge carrier transport. Alternating (P1) and ternary (P2) conjugated polymers were designed, synthesized and used for fabrication of photovoltaic devices. [GRAPHICS] .

  • 28.
    Gedefaw, Desta
    et al.
    Gothenburg University.
    Zhou, Yi
    Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics . Linköping University, The Institute of Technology.
    Hellstrom, Stefan
    Chalmers Institute of Technology.
    Lindgren, Lars
    Chalmers Institute of Technology.
    Andersson, L.Mattias
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Mammo, Wendimagegn
    Chalmers Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Andersson, Mats R
    Chalmers Institute of Technology.
    Alternating copolymers of fluorene and donor-acceptor-donor segments designed for miscibility in bulk heterojunction photovoltaics2009In: JOURNAL OF MATERIALS CHEMISTRY, ISSN 0959-9428, Vol. 19, no 30, p. 5359-5363Article in journal (Refereed)
    Abstract [en]

    A novel copolymer based on alternating fluorene and donor-acceptor-donor segments is reported, together with its photovoltaic properties in blends with fullerene derivatives. The balanced electron and hole mobility of the blends leads to a power-conversion efficiency of 2-3% under solar illumination.

  • 29.
    Guo, Yiting
    et al.
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Liu, Yanfeng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhu, Qinglian
    Xi An Jiao Tong Univ, Peoples R China.
    Li, Cheng
    Chinese Acad Sci, Peoples R China.
    Jin, Yingzhi
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Puttisong, Yuttapoom
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Liu, Feng
    Hebei Univ, Peoples R China.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Ma, Wei
    Xi An Jiao Tong Univ, Peoples R China.
    Li, Weiwei
    Chinese Acad Sci, Peoples R China.
    Effect of Side Groups on the Photovoltaic Performance Based on Porphyrin-Perylene Bisimide Electron Acceptors2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 38, p. 32454-32461Article in journal (Refereed)
    Abstract [en]

    In this work, we developed four porphyrin-based small molecular electron acceptors for non-fullerene organic solar cells, in which different side groups attached to the porphyrin core were selected in order to achieve optimized performance. The molecules contain porphyrin as the core, perylene bisimides as end groups, and the ethynyl unit as the linker. Four side groups, from 2,6-di(dodecyloxy)phenyl to (2-ethylhexyl)thiophen-2-yl, pentadecan-7-yl, and 3,5-di(dodecyloxy)phenyl unit, were applied into the electron acceptors. The new molecules exhibit broad absorption spectra from 300 to 900 nm and high molar extinction coefficients. The molecules as electron acceptors were applied into organic solar cells, showing increased power conversion efficiencies from 1.84 to 5.34%. We employed several techniques, including photoluminescence spectra, electroluminescence spectra, atomic force microscopy, and grazing-incidence wide-angle X-ray to probe the blends to find the effects of the side groups on the photovoltaic properties. We found that the electron acceptors with 2,6-di(dodecyloxy)phenyl units show high-lying frontier energy levels, good crystalline properties, and low nonradiative recombination loss, resulting in possible large phase separation and low energy loss, which is responsible for the low performance. Our results provide a detailed study about the side groups of non-fullerene materials, demonstrating that porphyrin can be used to design electron acceptors toward near-infrared absorption.

  • 30.
    Hamedi, Mahiar Max
    et al.
    KTH Royal Inst Technol, Sweden.
    Herland, Anna
    KTH Royal Inst Technol, Sweden; Karolinska Inst, Sweden.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Pei, Qibing
    Univ Calif Los Angeles, CA 90095 USA.
    Organic Polymer Electronics - A Special Issue in Honor of Prof. Olle Inganas2019In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 31, no 22, article id 1901940Article in journal (Other academic)
    Abstract [en]

    n/a

  • 31.
    He, Youjun
    et al.
    Chinese Acadamy of Science.
    Zhou, Yi
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhao, Guangjin
    Chinese Acadamy of Science.
    Min, Jie
    Chinese Acadamy of Science.
    Guo, Xia
    Chinese Acadamy of Science.
    Zhang, Bo
    Chinese Acadamy of Science.
    Zhang, Maojie
    Chinese Acadamy of Science.
    Zhang, Jing
    Chinese Acadamy of Science.
    Li, Yongfang
    Chinese Acadamy of Science.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Poly(4,8-bis(2-ethylhexyloxy)benzo[1,2-b:4,5-b ]dithiophene vinylene): Synthesis, Optical and Photovoltaic Properties2010In: JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY, ISSN 0887-624X, Vol. 48, no 8, p. 1822-1829Article in journal (Refereed)
    Abstract [en]

    A new benzodithiophene (BDT)-based polymer, poly(4,8-bis(2-ethylhexyloxy)benzo[1,2-b:4,5-b]dithiophene vinylene) (PBDTV), was synthesized by Pd-catalyzed Stille-coupling method. The polymer is soluble in common organic solvents and possesses high thermal stability. PBDTV film shows a broad absorption band covering from 350 nm to 618 nm, strong photoluminescence peaked at 545 nm and high hole mobility of 4.84 x 10(-3) cm(2)/Vs. Photovoltaic properties of PBDTV were studied by fabricating the polymer solar cells based on PBDTV as donor and PC70BM as acceptor. With the weight ratio of PBDTV: PC70BM of 1:4 and the active layer thickness of 65 nm, the power conversion efficiency of the device reached 2.63% with V-oc = 0.71 V, I-sc = 6.46 mA/cm(2), and FF = 0.57 under the illumination of AM1.5, 100 mW/cm(2).

  • 32.
    Hellstrom, Stefan
    et al.
    Chalmers.
    Lindgren, Lars J
    Chalmers.
    Zhou, Yi
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Andersson, Mats R
    Chalmers.
    Synthesis and characterization of three small band gap conjugated polymers for solar cell applications2010In: POLYMER CHEMISTRY, ISSN 1759-9954, Vol. 1, no 8, p. 1272-1280Article in journal (Refereed)
    Abstract [en]

    We report on a new series of small band gap conjugated polymers utilizing donor-acceptor-donor substructures in the polymer backbone to broaden and extend the optical absorption to longer wavelengths. Three polymers were prepared by Suzuki polymerization, using the same donor-acceptor-donor segment but with different comonomers. The goal was to investigate how the optical and electronic properties of the polymers were influenced by the different comonomers. Electrochemical spectroscopy, using square-wave voltammetry, shows that increasing the electron-donating strength of the comonomer will raise the HOMO energy level of the polymer, resulting in a decreased band gap. This result is also manifested by comparing open-circuit voltages from the corresponding laboratory fabricated solar cells. The best performing photovoltaic cell, based on APFO-Green15/[60]PCBM (1 : 4 w/w), reached a J(sc) of 4.2 mA cm(-2), a V-oc of 0.73 V, and a FF of 0.54, giving a PCE of 1.7%.

  • 33.
    Hellstrom, Stefan
    et al.
    Chalmers.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Andersson, Mats R
    Chalmers.
    Structure-property relationships of small bandgap conjugated polymers for solar cells2009In: DALTON TRANSACTIONS, ISSN 1477-9226, Vol. 45, p. 10032-10039Article in journal (Refereed)
    Abstract [en]

    Conjugated polymers as electron donors in solar cells based on donor/acceptor combinations are of great interest, partly due to the possibility of converting solar light with a low materials budget. Six small bandgap polymers with optical bandgap ranging from 1.0-1.9 eV are presented in this paper. All polymers utilize an electron donor-acceptor-donor (DAD) segment in the polymer backbone, creating a partial charge-transfer, to decrease the bandgap. The design, synthesis and the optical characteristics as well as the solar cell characteristics of the polymers are discussed. The positions of the energy levels of the conjugated polymer relative to the electron acceptor are of significant importance and determine not only the driving force for exciton dissociation but also the maximum open-circuit voltage. This work also focuses on investigating the redox behavior of the described conjugated polymers and electron acceptors using square wave voltammetry. Comparing the electrochemical data gives important information of the structure-property relationships of the polymers.

  • 34.
    Hou, Lintao
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Wang, Ergang
    Chalmers.
    Bergqvist, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Andersson, Viktor
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Wang, Zhongqiang
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Müller, Christian
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Campoy-Quiles, Mariano
    Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Esfera UAB, Bellaterra, Spain.
    R Andersson, Mats
    Materials and Surface Chemistry/Polymer Technology, Chalmers University of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Lateral Phase Separation Gradients in Spin-Coated Thin Films of High-Performance Polymer: Fullerene Photovoltaic Blends2011In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 21, no 16, p. 3169-3175Article in journal (Refereed)
    Abstract [en]

    In this study, it is demonstrated that a finer nanostructure produced under a rapid rate of solvent removal significantly improves charge separation in a high-performance polymer: fullerene bulk-heterojunction blend. During spin-coating, variations in solvent evaporation rate give rise to lateral phase separation gradients with the degree of coarseness decreasing away from the center of rotation. As a result, across spin-coated thin films the photocurrent at the first interference maximum varies as much as 25%, which is much larger than any optical effect. This is investigated by combining information on the surface morphology of the active layer imaged by atomic force microscopy, the 3D nanostructure imaged by electron tomography, film formation during the spin coating process imaged by optical interference and photocurrent generation distribution in devices imaged by a scanning light pulse technique. The observation that the nanostructure of organic photovoltaic blends can strongly vary across spin-coated thin films will aid the design of solvent mixtures suitable for high molecular-weight polymers and of coating techniques amenable to large area processing.

  • 35.
    Hou, Qiong
    et al.
    S China Normal University, Peoples R China .
    Chen, Yiquan
    S China Normal University, Peoples R China .
    Zhen, Hongyu
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology. Zhejiang Univ, Peoples R China Linkoping Univ, Dept Phys Chem and Biol IFM, SE-58183 Linkoping, Sweden .
    Ma, Zaifei
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Hong, Wenbiao
    S China Normal University, Peoples R China .
    Shi, Guang
    S China Normal University, Peoples R China .
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    A triphenylamine-based four-armed molecule for solution-processed organic solar cells with high photo-voltage2013In: JOURNAL OF MATERIALS CHEMISTRY A, ISSN 2050-7488, Vol. 1, no 16, p. 4937-4940Article in journal (Refereed)
    Abstract [en]

    A new four-armed molecule Th-4(DTPAB) with a triphenylamine-benzothiadiazole-triphenylamine unit as the core and 4-hexylthiophene as arms was synthesized. Solution-processed organic solar cells based on blends of Th-4(DTPAB) and PC71BM demonstrate a power conversion efficiency of 3.18% with a high open circuit voltage of 0.96 V.

  • 36.
    Inganäs, Olle
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Roman, L.S.
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Johansson, D.M.
    Department of Polymer Technology, Chalmers University of Technology, S-412 96 Göteborg, Sweden.
    Andersson, M.R.
    Department of Polymer Technology, Chalmers University of Technology, S-412 96 Göteborg, Sweden.
    Hummelen, J.C.
    Stratingh Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands.
    Recent progress in thin film organic photodiodes2001In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 121, no 1-3, p. 1525-1528Article in journal (Refereed)
    Abstract [en]

    We review current developments in organic photodiodes, with special reference to multilayer thin film optics, and modeling of organic donor-acceptor photodiodes. We indicate possibilities to enhance light absorption in devices by nanopatterning as well as by blending, and also discuss materials science issues of nanostructure in blends and in vertically stratified multilayer devices. Our current best devices have external efficiencies of 30-50% in between 400-600 nm, and show fill factors of 0.54 illuminated under weak monochromatic light.

  • 37.
    Inganäs, Olle
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Svensson, M.
    Materials and Surface Chemistry, Chalmers University of Technology, 412 96 Göteborg, Sweden.
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Gadisa, Abay
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Persson, Nils-Krister
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Wang, Xiangjun
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Andersson, M.R.
    Materials and Surface Chemistry, Chalmers University of Technology, 412 96 Göteborg, Sweden.
    Low bandgap alternating polyfluorene copolymers in plastic photodiodes and solar cells2004In: Applied Physics A: Materials Science & Processing, ISSN 0947-8396, E-ISSN 1432-0630, Vol. 79, no 1, p. 31-35Article in journal (Refereed)
    Abstract [en]

    We report a comparative study of plastic photodiodes using four different copolymers of fluorene, with a variation of alkyl side chain length and chemical structure. Photodiode materials are formed by blending the polymers with a fullerene derivative and spincoating the blend solution. A photovoltage of 1 V is obtained in devices, where the anode is a doped polymer and the cathode is LiF/Al. Monochromatic quantum efficiencies are better than 40% over most of the absorption range, and under solar light AM 1.5 simulation, we reach energy efficiencies beyond 2%. The high fill factors obtained in some of the devices indicate that these are of interest for more elaborate optimisation. Reasons for the benign electrical transport are discussed. © Springer-Verlag 2004.

  • 38.
    Inganäs, Olle
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Polymer optoelectronics - towards nanometer dimensions2003In: NANOTECHNOLOGY AND NANO-INTERFACE CONTROLLED ELECTRONIC DEVICES, p. 65-81Article in journal (Refereed)
    Abstract [en]

    n/a

  • 39.
    Inganäs, Olle
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Andersson, Mats R
    Chalmers, Sweden .
    Alternating Copolymers and Alternative Device Geometries for Organic Photovoltaics2012In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 41, p. 138-142Article in journal (Refereed)
    Abstract [en]

    The efficiency of conversion of light to electrical energy with the help of conjugated polymers and molecules is rapidly improving. The optical absorption properties of these materials can be designed, and implemented via molecular engineering. Full coverage of the solar spectrum is thus feasible. Narrow absorption spectra allow construction of tandem solar cells. The poor transport properties of these materials require thin devices, which limits optical absorption. Alternative device geometries for these flexible materials compensate for the optical absorption by light trapping, and allow tandem cells.

  • 40.
    Inganäs, Olle
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Andersson, Mats R
    Chalmers.
    Alternating Polyfluorenes Collect Solar Light in Polymer Photovoltaics2009In: ACCOUNTS OF CHEMICAL RESEARCH, ISSN 0001-4842, Vol. 42, no 11, p. 1731-1739Article in journal (Refereed)
    Abstract [en]

    The effort to improve the energy conversion efficiency of polymer solar cells has led to the design of novel donor polymers. To improve open circuit photovoltages (OCVs) and the spectral coverage of the solar spectrum, researchers have looked for materials with high HOMO values, an easily modified electronic structure, and sufficient electronic transport within the polymers. One advance in design from our laboratories has been the development of a class of alternating polyfluorene copolymers (APFOs), which can be combined with fullerenes to make bulk heterojunction materials for photovoltaic conversion. This Account describes copolymers of fluorene that we designed to expand the range the optical absorption of solar cells to include wavelengths out to 1000 nm. In most cases, we combine these polymers with acceptors from the fullerene family, typically the phenyl C-61 butyric acid methyl ester (PCBM) molecule, to generate solar cell materials. The synthesis of alternating copolymers of fluorene with various donor-acceptor-don or elements provides the opportunity to shift both HOMO and LUMO, which we have followed by electrochemical spectroscopy. Moving the LUMO of the APFOs farther from the vacuum level eventually leads to a situation where the driving force for photo-induced charge transfer from polymer donor to fullerene acceptor goes to zero, resulting in inefficient charge generation. Moving the HOMO level closer to the vacuum level reduces the OCV of devices made from bulk heterojunction blends. As we move the bandgap toward lower energies and increase the overlap of optical absorption with the solar spectrum, both these events eventually occur. In devices based on these APFO/fullerene blends, the performance depends on the OCV, the photocurrent under solar illumination, and the fill factor. The fill factor is influenced by electrical transport and charge generation. Optimizing these parameters requires new solutions to the perennial conflict between optically thin devices, where electrical extraction of charge is not a limitation, and the optically thick devices, where extraction of charge is hampered by trapping and recombination. As a result, we have developed methods to trap light in optically thin devices. When the thin film flexible solar cells are folded, multiple reflection between adjacent solar cells leads to a longer path length for the photon through the devices and considerable improvement of the optical dissipation in the active material. These optical tricks also enable an alternative route to tandem devices, where two different bandgap materials are located on adjacent folds. Thus light not absorbed in one cell is reflected onto the next cell to produce an effective optical series arrangement. Using experiments and simulations of the light trapping effects, we demonstrate power conversion efficiency enhancements of up to a factor of 1.8.

  • 41.
    Inganäs, Olle
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Tvingstedt, Kristofer
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Andersson, Lars Mattias
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Hellstrom, Stefan
    Chalmers.
    Andersson, Mats R.
    Chalmers.
    Polymer Photovoltaics with Alternating Copolymer/Fullerene Blends and Novel Device Architectures2010In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 22, no 20, p. E100-E116Article in journal (Refereed)
    Abstract [en]

    The synthesis of novel conjugated polymers, designed for the purpose of photovoltaic energy conversion, and their properties in polymer/fullerene materials and photovoltaic devices are reviewed. Two families of main chain polymer donors, based on fluorene or phenylene and donor-acceptor-donor comonomers in alternating copolymers, are used to absorb the high-energy parts of the solar spectrum and to give high photovoltages in combinations with fullerene acceptors in devices. These materials are used in alternative photovoltaic device geometries with enhanced light incoupling to collect larger photocurrents or to enable tandem devices and enhance photovoltage.

  • 42.
    Inganäs, Olle
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics.
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics.
    Wang, Xiangjun
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics.
    Gadisa, Abay
    IPS/ÌFM Linköpings universitet.
    Persson, Nils-Krister
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics.
    Svensson, Mattias
    Chalmers Tekniska Högskola.
    Perzon, Erik
    Chalmers Tekniska Högskola.
    Mammo, W
    Chalmers Tekniska Högskola.
    Andersson, M.R.
    Chalmers Tekniska Högskola.
    Alternating fluorene copolymer/fullerene blend solar cells2005In: Organic Photovoltaics: Mechanisms, Materials and Devices / [ed] Sam-Shajing Sun, Niyazi Serdar Sariciftci, Boca Raton, FL, USA: CRC Press , 2005, 1, p. 387-402Chapter in book (Other academic)
    Abstract [en]

    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 Devicesfills 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.

  • 43.
    J Lindgren, Lars
    et al.
    Chalmers.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Andersson, Mattias
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Barrau, Sophie
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Hellstrom, Stefan
    Chalmers.
    Mammo, Wendimagegn
    Chalmers.
    Perzon, Erik
    Chalmers.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Andersson, Mats R
    Chalmers.
    Synthesis, Characterization, and Devices of a Series of Alternating Copolymers for Solar Cells2009In: CHEMISTRY OF MATERIALS, ISSN 0897-4756, Vol. 21, no 15, p. 3491-3502Article in journal (Refereed)
    Abstract [en]

    In this study we report the synthesis, characterization. and photovoltaic properties of a series of six Conjugated polymers based on donor-acceptor-donor (DAD) structure. The polymers are obtained via Suzuki polymerization of different alkoxy-substituted DAD monomers together with a substituted fluorene or phenylene monomer. Application of polymers as light-harvesting and electron-donating materials in solar cells, in conjunction with both [60]PCBM and [70]PCBM as acceptors, show power-conversion efficiencies (PCEs) up to 2.9%, values obtained without extensive optimization work. Furthermore, atomic force microscopy and field-effect transistor (FET) mobility measurements of acceptor-polymer mixtures show that differences in substitution on the polymers affect morphology, mobility, and device performance. Within the series of polymers, all showing similar optical absorption and redox behavior, substituents play an important role in phase separation on a micrometer scale, which in turn has a large impact on device performance. The phase-separation behavior is clearly seen in [70]PCBM devices where the best-performing devices are obtained using the polymers with short alkoxy groups or no substituents together with a high speed of spin coating during device preparation.

  • 44.
    Jespersen, Kim G
    et al.
    Chemical Physics Kemicentrum.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Gadisa, Abay
    Linköping University, Department of Physics, Chemistry and Biology.
    Sundström, Villy
    Chemical Physics Kemicentrum.
    Yartsev, Arkady
    Chemical Physics Kemicentrum.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Charge formation and transport in bulk-heterojunction solar cells based on alternating polyfluorene copolymers blended with fullerenes2006In: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 7, p. 235-242Article in journal (Refereed)
  • 45.
    Jia, Yuehua
    et al.
    Tianjin University of Technology, Peoples R China .
    Yang, Liying
    Tianjin University of Technology, Peoples R China .
    Qin, Wenjing
    Tianjin University of Technology, Peoples R China .
    Yin, Shougen
    Tianjin University of Technology, Peoples R China .
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics.
    Wei, Jun
    Tianjin University of Technology, Peoples R China .
    Efficient polymer bulk heterojunction solar cells with cesium acetate as the cathode interfacial layer2013In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 50, p. 565-569Article in journal (Refereed)
    Abstract [en]

    The enhanced performance of polymer solar cells based on regioregular poly(3-hexylthiophene) (P3HT) and methanofullerene [6,6]-phenyl C-61-butyric acid methyl ester (PCBM) blend was achieved by using cesium acetate (CH3COOCs) as cathode buffer layer. Under 100 mW/cm(2) white light illumination, the device with 0.8 nm thick CH3COOCs as cathode buffer layer exhibits power conversion efficiency (PCE) as high as (4.16 +/- 0.02) %. Compared to the control devices without cathode buffer layer and with LiF as cathode buffer layer, the PCE is enhanced similar to 100% and similar to 31%, respectively. The introduction of the CH3COOCs buffer layer effectively improves the photo-generated charge collection. The Kelvin Probe measurement shows that the work function of the CH3COOCs is estimated to be -4.0 eV, which has an ideal energy band match with PCBM and a good property for electron collection. The static contact angle results indicated that the CH3COOCs with the hydrophobic CH3COO- group has an improved wettability between the buffer layer and the hydrophobic organic active layer surface, resulting in better interfacial contact and reduced contact resistance. The improved performance may be attributed to the dissociation of semi-conducting CH3COOCs upon deposition to liberate Cs with a low work function, which reduces the interface resistance of the active layer and the cathode and enhances the interior electric field that may result in efficient charge transportation. Therefore, the CH3COOCs interlayer could be a promising alternative to LiF to improve the efficiency of the electron collection of polymer bulk heterojunction solar cells.

  • 46.
    Jin, Yingzhi
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Li, Zaifang
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Leiqiang, Qin
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Mao, Lin
    Huazhong University of Science and Technology, Peoples R China; Huazhong University of Science and Technology, Peoples R China.
    Wang, Yazhong
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering.
    Qin, Fei
    Huazhong University of Science and Technology, Peoples R China; Huazhong University of Science and Technology, Peoples R China.
    Liu, Yanfeng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhou, Yinhua
    Huazhong University of Science and Technology, Peoples R China; Huazhong University of Science and Technology, Peoples R China; South China University of Technology, Peoples R China.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Laminated Free Standing PEDOT:PSS Electrode for Solution Processed Integrated Photocapacitors via Hydrogen-Bond Interaction2017In: ADVANCED MATERIALS INTERFACES, ISSN 2196-7350, Vol. 4, no 23, article id 1700704Article in journal (Refereed)
    Abstract [en]

    In this work, a novel lamination method employing hydrogen-bond interaction to assemble a highly conductive free standing poly(3,4-ethylene dioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) film as a common electrode is demonstrated in a solution processed metal-free foldable integrated photocapacitor (IPC) composed of a monolithic organic solar cell (OSC) and a capacitor. The highlights of the work are:(1) micrometer free standing PEDOT:PSS electrode is successfully laminated onto a relatively large area (1 cm(2)) OSCs; (2) a free standing capacitor based on the PEDOT:PSS electrode is achieved; (3) the IPC demonstrates an overall efficiency of 2% and an energy storage efficiency of 58%, which is comparable with those of IPCs based on metallic common electrodes; (4) the novel lamination method for PEDOT:PSS electrode enables free standing PEDOT:PSS broad applications in solution processed flexible organic electronics, especially tandem or/and integrated organic electronic devices. Furthermore, the IPC is foldable with excellent cycling stability (no decay after 100 recycles at 1 mA cm(-2)). These results indicate that free standing PEDOT:PSS film is a promising candidate as common electrodes for IPCs to break the restrictions of metal electrodes. The demonstrated lamination method will greatly extend the applications of PEDOT:PSS electrodes to large area flexible organic electronic devices.

  • 47.
    Jin, Yingzhi
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhang, Yanxin
    Tsinghua Univ, Peoples R China.
    Liu, Yanfeng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Xue, Jie
    Tsinghua Univ, Peoples R China.
    Li, Weiwei
    Beijing Univ Chem Technol, Peoples R China.
    Qiao, Juan
    Tsinghua Univ, Peoples R China.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Limitations and Perspectives on Triplet-Material-Based Organic Photovoltaic Devices2019In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 31, no 22, article id 1900690Article in journal (Refereed)
    Abstract [en]

    Organic photovoltaic cells (OPVs) have attracted broad attention and become a very energetic field after the emergence of nonfullerene acceptors. Long-lifetime triplet excitons are expected to be good candidates for efficiently harvesting a photocurrent. Parallel with the development of OPVs based on singlet materials (S-OPVs), the potential of triplet materials as photoactive layers has been explored. However, so far, OPVs employing triplet materials in a bulk heterojunction have not exhibited better performance than S-OPVs. Here, the recent progress of representative OPVs based on triplet materials (T-OPVs) is briefly summarized. Based on that, the performance limitations of T-OPVs are analyzed. The shortage of desired triplet materials with favorable optoelectronic properties for OPVs, the tradeoff between long lifetime and high binding energy of triplet excitons, as well as the low charge mobility in most triplet materials are crucial issues restraining the efficiencies of T-OPVs. To overcome these limitations, first, novel materials with desired optoelectronic properties are urgently demanded; second, systematic investigation on the contribution and dynamics of triplet excitons in T-OPVs is necessary; third, close multidisciplinary collaboration is required, as proved by the development of S-OPVs.

    The full text will be freely available from 2020-04-08 14:03
  • 48.
    Jönsson, Stina
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Carlegrim, Elin
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Salaneck, William R
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Fahlman, Mats
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Photoelectron spectroscopy of the contact between the cathode and the active layers in plastic solar cells: the role of LiF2005In: Japanese Journal of Applied Physics, ISSN 0021-4922, E-ISSN 1347-4065, Vol. 44, no 6A, p. 3695-3701Article in journal (Refereed)
    Abstract [en]

    The surfaces and electrode interfaces of a polymer blend used in prototype solar cells have been characterized with photoelectron spectroscopy. The polymer blend in question is a 1:4 mixture of APFO-3:PCBM. Based on surface analysis of the pristine film we can conclude that the surface of the blend is a 1:1 mixture of APFO-3 and PCBM. The electrode systems studied are the widely used Al and Al/LiF contacts. LiF prevents formation at the Al/organic interface of Al-organic complexes that destroy the π-conjugation. In addition to this, there are two other beneficial, thickness dependent, effects. Decomposition of LiF occurs for thin enough layers in which the LiF species are in contact with both the organic film and the Al atoms, which creates a low workfunction contact. For thicker (multi)layers, the dipole formed at the LiF/organic interface is retained as no decomposition of the LiF occurs upon Al deposition.

  • 49.
    Krebs, Frederik C
    et al.
    Tech University Denmark, Riso Natl Lab Sustainable Energy, DK-4000 Roskilde, Denmark .
    Gevorgyan, Suren A
    Tech University Denmark, Riso Natl Lab Sustainable Energy, DK-4000 Roskilde, Denmark .
    Gholamkhass, Bobak
    Simon Fraser University, Burnaby, BC V5A 1S6 Canada .
    Holdcroft, Steven
    Simon Fraser University, Burnaby, BC V5A 1S6 Canada .
    Schlenker, Cody
    University So Calif, Department Chemistry, Loker Hydrocarbon Research Institute, Los Angeles, CA 90089 USA Centre Energy Nanosci and Technology, Los Angeles, CA 90089 USA .
    Thompson, Mark E
    University So Calif, Department Chemistry, Loker Hydrocarbon Research Institute, Los Angeles, CA 90089 USA Centre Energy Nanosci and Technology, Los Angeles, CA 90089 USA .
    Thompson, Barry C
    University So Calif, Department Chemistry, Loker Hydrocarbon Research Institute, Los Angeles, CA 90089 USA Centre Energy Nanosci and Technology, Los Angeles, CA 90089 USA .
    Olson, Dana
    NREL, Golden, CO 80401 USA .
    Ginley, David S
    NREL, Golden, CO 80401 USA .
    Shaheen, Sean E
    NREL, Golden, CO 80401 USA University Denver, Department Phys and Astron, Denver, CO 80208 USA .
    Alshareef, Husam N
    University Texas Dallas, Richardson, TX 75080 USA .
    Murphy, John W
    University Texas Dallas, Richardson, TX 75080 USA .
    Youngblood, W Justin
    University N Texas, Department Chemistry, Denton, TX 76201 USA .
    Heston, Nathan C
    University Florida, Department Phys, Centre Macromol Science and Engn, Gainesville, FL 32611 USA .
    Reynolds, John R
    University Florida, Department Chemistry, Centre Macromol Science and Engn, Gainesville, FL 32611 USA .
    Jia, Shijun
    Plextronics Inc, Pittsburgh, PA 15238 USA .
    Laird, Darin
    Plextronics Inc, Pittsburgh, PA 15238 USA .
    Tuladhar, Sachetan M
    University London Imperial Coll Science Technology and Med, Department Phys, Blackett Lab, London SW7 2AZ, England .
    Dane, Justin G A
    University London Imperial Coll Science Technology and Med, Department Phys, Blackett Lab, London SW7 2AZ, England .
    Atienzar, Pedro
    University London Imperial Coll Science Technology and Med, Department Phys, Blackett Lab, London SW7 2AZ, England .
    Nelson, Jenny
    University London Imperial Coll Science Technology and Med, Department Phys, Blackett Lab, London SW7 2AZ, England .
    Kroon, Jan M
    ECN Solar Energy, NL-1755 ZG Petten, Netherlands .
    Wienk, Martijn M
    Eindhoven University Technology, Lab Macromol and Organ Chemistry, NL-5600 MB Eindhoven, Netherlands .
    Janssen, Rene A J
    Eindhoven University Technology, Lab Macromol and Organ Chemistry, NL-5600 MB Eindhoven, Netherlands .
    Tvingstedt, Kristofer
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Andersson, Mattias
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Lira-Cantu, Monica
    Centre Invest Nanociencia and Nanotecnol, E-08193 Barcelona, Spain .
    de Bettignies, Remi
    CEA INES DRI, Lab Composants Solaires, F-73377 Le Bourget Du lac, France .
    Guillerez, Stephane
    CEA INES DRI, Lab Composants Solaires, F-73377 Le Bourget Du lac, France .
    Aernouts, Tom
    IMEC, PV Department, B-3001 Louvain, Belgium .
    Cheyns, David
    IMEC, PV Department, B-3001 Louvain, Belgium .
    Lutsen, Laurence
    IMEC, IMOMEC, B-3590 Diepenbeek, Belgium .
    Zimmermann, Birger
    Fraunhofer Institute Solare Energiesyst ISE, Department Mat Research and Appl Opt, D-79110 Freiburg, Germany .
    Wuerfel, Uli
    Fraunhofer Institute Solare Energiesyst ISE, Department Mat Research and Appl Opt, D-79110 Freiburg, Germany .
    Niggemann, Michael
    Fraunhofer Institute Solare Energiesyst ISE, Department Mat Research and Appl Opt, D-79110 Freiburg, Germany .
    Schleiermacher, Hans-Frieder
    Fraunhofer Institute Solare Energiesyst ISE, Department Mat Research and Appl Opt, D-79110 Freiburg, Germany .
    Liska, Paul
    Ecole Polytech Fed Lausanne, LPI, Institute Chemistry Science and Engn, Fac Basic Science, CH-1015 Lausanne, Switzerland .
    Graetzel, Michael
    Ecole Polytech Fed Lausanne, LPI, Institute Chemistry Science and Engn, Fac Basic Science, CH-1015 Lausanne, Switzerland .
    Lianos, Panagiotis
    University Patras, Department Engn Science, Patras 26500, Greece .
    Katz, Eugene A
    Ben Gurion University Negev, Jacob Blaustein Institute Desert Research, Department Solar Energy and Environm Phys, IL-84990 Sede Boqer, Israel .
    Lohwasser, Wolfgang
    Alcan Packaging Singen GmbH, D-78221 Singen, Germany .
    Jannon, Bertrand
    Alcan Packaging Singen GmbH, D-78221 Singen, Germany .
    A round robin study of flexible large-area roll-to-roll processed polymer solar cell modules2009In: SOLAR ENERGY MATERIALS AND SOLAR CELLS, ISSN 0927-0248, Vol. 93, no 11, p. 1968-1977Article in journal (Refereed)
    Abstract [en]

    A round robin for the performance of roll-to-roll coated flexible large-area polymer solar-cell modules involving 18 different laboratories in Northern America, Europe and Middle East is presented. The study involved the performance measurement of the devices at one location (Riso DTU) followed by transportation to a participating laboratory for performance measurement and return to the starting location (Riso DTU) for re-measurement of the performance. It was found possible to package polymer solar-cell modules using a flexible plastic barrier material in such a manner that degradation of the devices played a relatively small role in the experiment that has taken place over 4 months. The method of transportation followed both air-mail and surface-mail paths.

  • 50.
    Leiqiang, Qin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Tao, Quanzheng
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    El Ghazaly, Ahmed
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Fernandez-Rodriguez, Julia
    University of Gothenburg, Sweden.
    Persson, Per
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Rosén, Johanna
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    High-Performance Ultrathin Flexible Solid-State Supercapacitors Based on Solution Processable Mo1.33C MXene and PEDOT:PSS2018In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 28, no 2, article id 1703808Article in journal (Refereed)
    Abstract [en]

    MXenes, a young family of 2D transition metal carbides/nitrides, show great potential in electrochemical energy storage applications. Herein, a high performance ultrathin flexible solid-state supercapacitor is demonstrated based on a Mo1.33C MXene with vacancy ordering in an aligned layer structure MXene/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) composite film posttreated with concentrated H2SO4. The flexible solid-state supercapacitor delivers a maximum capacitance of 568 F cm-3, an ultrahigh energy density of 33.2 mWh cm-3 and a power density of 19 470 mW cm-3. The Mo1.33C MXene/PEDOT:PSS composite film shows a reduction in resistance upon H2SO4 treatment, a higher capacitance (1310 F cm-3) and improved rate capabilities than both pristine Mo1.33C MXene and the nontreated Mo1.33C/PEDOT:PSS composite films. The enhanced capacitance and stability are attributed to the synergistic effect of increased interlayer spacing between Mo1.33C MXene layers due to insertion of conductive PEDOT, and surface redox processes of the PEDOT and the MXene.

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