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  • 201.
    Johansson, D.M.
    et al.
    Department of Organic Chemistry, Chalmers University of Technology, S-412 96 Göteborg, Sweden.
    Srdanov, G.
    UNIAX Corporation, 6780 Cortona Drive, Santa Barbara, CA 93117, United States.
    Yu, G.
    UNIAX Corporation, 6780 Cortona Drive, Santa Barbara, CA 93117, United States.
    Theander, M.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Andersson, M.R.
    Department of Polymer Technology, Chalmers University of Technology, S-412 96 Göteborg, Sweden.
    Synthesis and characterization of highly soluble phenyl-substituted poly(p-phenylenevinylenes)2000In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 33, no 7, p. 2525-2529Article in journal (Refereed)
    Abstract [en]

    We present the synthesis and characterization of soluble, high molecular weight phenyl-substituted poly(p-phenylenevinylenes). The studied polymers are poly(2-(2',5'-bis(2?-ethylhexyloxy)phenyl)- 1,4-phenylenevinylene) (BEHP-PPV) and copolymers of BEHP-PPV and poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV). Their photoluminescence and electroluminescence have been examined as well as their stability to air and light. The polymers emitted green and yellow light. Stability measurements showed increased stability compared to some previously known substituted PPVs.

  • 202. Johansson, DM
    et al.
    Theander, M
    Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Chalmers Univ Technol, Dept Organ Chem, SE-41296 Gothenburg, Sweden Linkoping Univ, IFM, Dept Phys, SE-58183 Linkoping, Sweden.
    Granlund, T
    Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Chalmers Univ Technol, Dept Organ Chem, SE-41296 Gothenburg, Sweden Linkoping Univ, IFM, Dept Phys, SE-58183 Linkoping, Sweden.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Andersson, MR
    Synthesis and characterization of polyfluorenes with light-emitting segments2001In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 34, no 6, p. 1981-1986Article in journal (Refereed)
    Abstract [en]

    Two new polymers consisting of poly(9-(2'-ethylhexyl)-9-hexylfluorene) (EHH-PF) with a small amount of substituted poly(p-phenylenevinylene) (PPV) segments have been synthesized and characterized. The synthetic route was designed to allow the incorporation of only one (or zero) PPV segments per polymer chain. Photoluminescence measurements showed that energy transfer from the PF segments to the more narrow band-gap PPV segments did occur, both in solution and in film. In the solid state, all emissions were detected from the PPV segments with photoluminescence quantum yields up to 68%. One of the polymers has been used as the active material in a microcavity laser device. The threshold for lasing is 2 muJ/cm(2).

  • 203.
    Johansson, D.M.
    et al.
    Department of Organic Chemistry, Chalmers Univ. Technol., SE-412 96, Göteborg, Sweden.
    Theander, M.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Andersson, M.R.
    Department of Polymer Technology, Chalmers Univ. Technol., SE-412 96, Göteborg, Sweden.
    Convenient synthetic route to poly(p-phenylene-1,2-diphenylvinylenes)2000In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 113, no 3, p. 293-297Article in journal (Refereed)
    Abstract [en]

    The synthesis and characterization of two soluble poly(p-phenylenevinylene)s substituted with phenyl groups on the vinylene moiety is reported. The polymers are poly(1,4-phenylene-1,2-diphenylvinylene) (PPV-DP) and poly(1,4-phenylene-1,2-(3'-(2?-ethylhexyloxy))-diphenylvinylene) (PPV-mEHDP). The monomers containing chloromethyl groups were polymerized with excess potassium tert-butoxide in dioxane at room temperature. The polymerization conditions are optimized. The photoluminescence (PL) properties of the polymers showed an increase in the PL efficiency in film from 19% for PPV-DP to 37% for PPV-mEHDP. Both polymers emitted green light with higher intensity in film than in solution.

  • 204. Johansson, DM
    et al.
    Theander, M
    Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Chalmers Univ Technol, Dept Organ Chem, SE-41296 Gothenburg, Sweden Linkoping Univ, Dept Phys IFM, SE-58183 Linkoping, Sweden UNIAX Corp, Goleta, CA 93117 USA.
    Srdanov, G
    Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Chalmers Univ Technol, Dept Organ Chem, SE-41296 Gothenburg, Sweden Linkoping Univ, Dept Phys IFM, SE-58183 Linkoping, Sweden UNIAX Corp, Goleta, CA 93117 USA.
    Yu, G
    Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Chalmers Univ Technol, Dept Organ Chem, SE-41296 Gothenburg, Sweden Linkoping Univ, Dept Phys IFM, SE-58183 Linkoping, Sweden UNIAX Corp, Goleta, CA 93117 USA.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Andersson, MR
    Influence of polymerization temperature on molecular weight, photoluminescence, and electroluminescence for a phenyl-substituted poly(p-phenylenevinylene)2001In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 34, no 11, p. 3716-3719Article in journal (Refereed)
    Abstract [en]

    We present the synthesis and characterization of poly(2-(2",5'-bis(2"-ethylhexyloxy)phenyl)-1,4-phenylenevinylene) (BEHP-PPV) polymerized at different temperatures. The photoluminescence efficiencies in the solid state of BEHP-PPV obtained at 144 and 0 degreesC are 28% and 60%, respectively. H-1 NMR measurements showed a lower concentration of structural defects for BEHP-PPV obtained at lower temperatures, which can explain the increased photoluminescence efficiencies for these polymers. Polymerization temperatures below 0 degreesC decrease the molecular weight without changing the photoluminescence efficiency to any large extent. The electroluminescence efficiencies follow the trend in the photoluminescence efficiencies.

  • 205. Johansson, DM
    et al.
    Wang, XJ
    Johansson, Tomas
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Yu, G
    Srdanov, G
    Andersson, MR
    Synthesis of soluble phenyl-substituted poly(p-phenylenevinylenes) with a low content of structural defects2002In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 35, no 13, p. 4997-5003Article in journal (Refereed)
    Abstract [en]

    The synthesis and characterization of two new soluble poly(p-phenylenevinylenes) (PPVs) are reported. The polymers are poly(2-2',5'-bis(octyloxy)benzene)-1,4-phenylenevinylene) (BOP-PPV) and poly(2-(2',5'-bis(octyloxy)benzene)-5-methoxy-1,4-phenylenevinylene) (BOPM-PPV). Both polymers have been polymerized at high and low temperatures to study the formation of structural defects. It is shown that both methoxy groups as side chains and low polymerization temperatures decrease the content of defects in the final polymer. As a consequence, the polymers with lower concentration of defects exhibit higher electroluminescence yields in light-emitting diodes. In addition to this, the polymers with a low content of defects exhibited longer operational lifetimes in these devices. The highest photoluminescence quantum yield in the solid state and electroluminescence efficiency were found to be 72% and 1.74%, respectively.

  • 206.
    Johansson, Patrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Jullesson, David
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Elfwing, Anders
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Liin, Sara
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Musumeci, Chiara
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zeglio, Erica
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Elinder, Fredrik
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Solin, Niclas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Electronic polymers in lipid membranes2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, no 11242Article in journal (Refereed)
    Abstract [en]

    Electrical interfaces between biological cells and man-made electrical devices exist in many forms, but it remains a challenge to bridge the different mechanical and chemical environments of electronic conductors (metals, semiconductors) and biosystems. Here we demonstrate soft electrical interfaces, by integrating the metallic polymer PEDOT-S into lipid membranes. By preparing complexes between alkyl-ammonium salts and PEDOT-S we were able to integrate PEDOT-S into both liposomes and in lipid bilayers on solid surfaces. This is a step towards efficient electronic conduction within lipid membranes. We also demonstrate that the PEDOT-S@alkyl-ammonium: lipid hybrid structures created in this work affect ion channels in the membrane of Xenopus oocytes, which shows the possibility to access and control cell membrane structures with conductive polyelectrolytes.

  • 207.
    Johansson, Tomas
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Mammo, W.
    Depts. Organ. Chem./Polymer Technol., Chalmers University of Technology, 412 83 Göteborg, Sweden, Addis Ababa University, Department of Chemistry, P.O. Box 1176, Addis Ababa, Ethiopia.
    Svensson, M.
    Depts. Organ. Chem./Polymer Technol., Chalmers University of Technology, 412 83 Göteborg, Sweden.
    Andersson, M.R.
    Depts. Organ. Chem./Polymer Technol., Chalmers University of Technology, 412 83 Göteborg, Sweden.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Electrochemical bandgaps of substituted polythiophenes2003In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 13, no 6, p. 1316-1323Article in journal (Refereed)
    Abstract [en]

    The electrochemical bandgaps for different soluble substituted polythiophenes have been measured by cyclic voltammetry. The effect of substituents on the oxidation/reduction potentials is discussed. Bandgaps obtained by cyclic voltammetry have been found to be in general higher than optical bandgaps. Among regioregular polymers substituted with a phenyl group at position 3 of the thiophene ring, examples are found that give very symmetric voltammograms. Rationalization for this behaviour is discussed from a conformational point of view.

  • 208.
    Johansson, Tomas
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Persson, Nils-Krister
    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 .
    Moving Redox Fronts in Conjugated Polymers Studies from Lateral Electrochemistry in Polythiophenes2004In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 151, no 4Article in journal (Refereed)
    Abstract [en]

    The propagation speed of the front of electrochemical conversion, from semiconductor to highly doped polymer, in films of regioregular poly(3-hexylthiophene) spin cast on insulating substrates was analyzed. Propagation of the p-doped zone in polymer electrochromic devices was imaged simultaneously with recording of electrochemical data. The current is proportional to the propagation speed and has a Tafel-like behavior when taking the resistive drop in the film into account. The resistivity in the film, which gradually lowers the propagation speed, was used for determination of the conductivity of the p-doped polymer. By combining these values with the doping charge injected into the film during front migration we estimated the hole carrier mobility for different doping levels. © 2004 The Electrochemical Society.

  • 209.
    Johansson, Tomas
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Pettersson, Lars
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Conductivity of de-doped poly(3,4-ethylenedioxythiophene)2002In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 129, no 3, p. 269-274Article in journal (Refereed)
    Abstract [en]

    The conductivity of chemically and electrochemically de-doped poly(3,4-ethylenedioxythiophene) (PEDOT) has been investigated in situ. We observe a decrease in the conductivity by 4-5 orders of magnitude. The change of conductivity is correlated to the change of electronic structure. We obtain the dielectric function of the polymer by spectroscopic ellipsometry and note that anisotropy is observed in both doped and neutral states. © 2002 Elsevier Science B.V. All rights reserved.

  • 210.
    Jonforsen, M.
    et al.
    Department of Polymer Technology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
    Ahmad, I.
    Johansson, Tomas
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Larsson, J.
    Department of Polymer Technology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
    Roman, L.S.
    Svensson, M.
    Department of Organic Chemistry, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Andersson, M.R.
    Department of Polymer Technology, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
    Photodiodes made from poly(pyridopyrazine vinylene): polythiophene blends2001In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 119, no 1-3, p. 185-186Article in journal (Refereed)
    Abstract [en]

    A PPV-type polymer with the pyridopyrazine heterocycle (EHH-PPyPzV) has been synthesised and found to have high electron affinity according to electrochemical measurements. When used as the electron accepting material in single-layer-photodiodes, with a thiophene copolymer (PEOPT-co-PAAPT) as the electron donating material, IPCE (incident photon to current conversion efficiency) up to 1% was measured. Atomic force microscopy was used to analyse the blend morphology in the devices.

  • 211. Jonforsen, M
    et al.
    Johansson, Tomas
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Andersson, MR
    Synthesis and characterization of soluble and n-dopable poly(quinoxaline vinylene)s and poly(pyridopyrazine vinylene)s with relatively small band gap2002In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 35, no 5, p. 1638-1643Article in journal (Refereed)
    Abstract [en]

    Synthesis and characterization of poly(quinoxaline vinylene)s and poly(pyridopyrazine vinylene)s with linear and branched aliphatic side chains are reported. The electron affinity of the polymers was measured with cyclic voltammetry (CV) and found to be highest for the pyridopyrazine vinylene polymers, Compared to CN-MEH-PPV, the pyridopyrazine vinylene polymers were easier to reduce, while the quinoxaline derivatives were harder. UV-vis absorption measurements showed that the polymers have relatively small band gaps.

  • 212.
    Jonforsen, M.
    et al.
    Department of Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
    Johansson, Tomas
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Spjuth, L.
    Department of Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Andersson, M.R.
    Department of Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
    Synthesis and characterization of poly(quinoxaline vinylene)s and poly(pyridopyrazine vinylene)s with phenyl substituted side-groups2002In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 131, no 1-3, p. 53-59Article in journal (Refereed)
    Abstract [en]

    Poly(quinoxaline vinylene) and poly(pyridopyrazine vinylene) with 3(2'-ethylhexyloxy)phenyl side-groups have been synthesized and compared with similar polymers with purely aliphatic side-chains. The new polymers had smaller bandgaps, and from cyclic voltammetry it was seen that the phenyl substituted side-groups made the polymers easier to reduce, with half wave potentials of -1.02 and -1.33 V versus Ag/AgCl for the poly(pyridopyrazine vinylene) and poly(quinoxaline vinylene) respectively. The attachment of the phenyl substituted side-groups had counteracting effects on the stability towards photo-oxidation, which resulted in improved stability of the poly(pyridopyrazine vinylene) compared to its equivalent with purely aliphatic side-chains, while the poly(quinoxaline vinylene) showed decreased stability. © 2002 Elsevier Science B.V. All rights reserved.

  • 213.
    Kaminorz, Y.
    et al.
    Institute of Physics, Condensed Matter Phys., Univ. P., Potsdam, Germany.
    Smela, E.
    Condensed Matter Phys. Chem. Dept., Ris Natl. Lab. FYS-124, P.O. B., Roskilde, Denmark.
    Johansson, Tomas
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Brehmer, L.
    Institute of Physics, Condensed Matter Phys., Univ. P., Potsdam, Germany.
    Andersson, M.R.
    Dept. Organ. Chem. Poly. Technol., Chalmers Univ. of Technol., S-412 96, Göteborg, Sweden.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Characteristics of polythiophene surface light emitting diodes2000In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 113, no 1, p. 103-114Article in journal (Refereed)
    Abstract [en]

    Surface light emitting diodes (SLEDs), in which previously microfabricated electrodes were coated with a conjugated polymer, were made with greatly different electrode spacings (250 nm and 10 or 20 µm) and with different electrode material combinations. The fabrication process allowed us to compare several electrode materials. The SLED structures also enabled imaging of the light emission zone with fluorescence video microscopy. Conventional sandwich structures were also made for comparison (electrode separation 50 nm). In this study, the emitting layer was poly[3-(2',5'-bis(1?,4?,7?trioxaoctyl)phenyl)- 2,2'-bithiophene] (EO-PT), a conjugated polymer based on polythiophene with oligo(ethyleneoxide) side chains. The current-voltage (I(V)) and light-voltage (L(V)) characteristics of the SLEDs were largely insensitive to electrode separation except at high voltages, at which the current in the devices with the largest separations was limited. Sandwich structures had the same light output at a given current. Light could be obtained in forward and reverse bias from indium tin oxide (ITO)-aluminum, gold silicide-aluminum, and gold silicide-gold SLEDs, but the turn-on voltages were lowest with the ITO-aluminum devices, and these were also the brightest and most reliable. Adding salt to the EO-PT increased the current and brightness, decreased the turn-on voltages, and made the I(V) characteristics symmetric, thus, a device with an electrode separation of 10 µm had the extraordinarily low turn-on voltage of 6 V. The location of the light emission was at the electron-injecting contact.

  • 214.
    Karlsson, Fredrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Åsberg, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Nilsson, Peter
    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.
    Interactions between a zwitterionic polythiophene derivative and oligonucleotides as resolved by fluorescence resonance energy transfer2005In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 17, no 16, p. 4204-4211Article in journal (Refereed)
    Abstract [en]

    The interactions between a zwitterionic polythiophene derivative, POWT, and DNA oligonucleotides in solution have been studied by FRET (fluorescence resonance energy transfer). When POWT and ssDNA are bound alone in a complex, the distance between them is at its smallest. The distance increases when adding complementary DNA, but POWT is still mainly bound to the first DNA strand. We find that two POWT chains bind to one DNA strand, and the two POWT chains seem held together in pairs, unable to separate, as they can only bind to and quench half their own amount of labeled DNA. This POWT−POWT complex appears to dissociate at lower concentrations. ssDNA attached to POWT in a complex can also be substituted by other ssDNA in solution; this occurs to 50% when the free DNA is present in 10-fold concentration compared to the ssDNA bound to POWT. Titration studies at different concentrations show positive cooperativity in the binding of POWT and ssDNA into a complex. The hybridization of complementary DNA to the same complex involves no cooperativity. These observations indicate interesting possibilities for the use of POWT as a DNA sensor.

  • 215.
    Karlsson, Roger H.
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Herland, Anna
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Hamedi, Mahiar
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics . Linköping University, The Institute of Technology.
    Åslund, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry . 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.
    Konradsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry . Linköping University, The Institute of Technology.
    Iron Catalyzed Polymerization of Alkoxysulfonate-Functionalized EDOT gives2007In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002Article in journal (Refereed)
  • 216.
    Karlsson, Roger
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Herland, Anna
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Hamedi, Mahiar
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Wigenius, Jens
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Åslund, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, The Institute of Technology.
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. 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.
    Konradsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Organic Chemistry. Linköping University, The Institute of Technology.
    Iron-Catalyzed Polymerization of Alkoxysulfonate-Functionalized 3,4-Ethylenedioxythiophene Gives Water-Soluble Poly(3,4-ethylenedioxythiophene) of High Conductivity2009In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 21, no 9, p. 1815-1821Article in journal (Refereed)
    Abstract [en]

    Chemical polymerization of a 3,4-ethylenedioxythiophene derivative bearing a sulfonate group (EDOTS) is reported. The polymer, PEDOT-S, is fully water-soluble and has been produced by polymerizing EDOT-S in water, using Na2S2O8 and a catalytic amount of FeCl3. Elemental analysis and XPS measurements indicate that PEDOT-S is a material with a substantial degree of self-doping, but also contains free sulfate ions as charge-balancing counterions of the oxidized polymer. Apart from self-doping PEDOT-S, the side chains enable full water solubility of the material; DLS studies show an average cluster size of only 2 nm. Importantly, the solvation properties of the PEDOT-S are reflected in spin-coated films, which show a surface roughness of 1.2 nm and good conductivity (12 S/cm) in ambient conditions. The electro-optical properties of this material are shown with cyclic voltammetry and spectroelectrochemical experiment reveals an electrochromic contrast (similar to 48% at lambda(max) = 606 nm).

  • 217.
    Koehler, M.
    et al.
    Depto. de Engenharia Elétrica, Univ. Federal do Paraná, 81531-990 Curitiba-PR, Brazil.
    Roman, L.S.
    Departamento de Física, Univ. Federal do Paraná, C.P. 19044, 81531-990 Curitiba-PR, Brazil.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Da, Luz M.G.E.
    Da Luz, M.G.E., Departamento de Física, Univ. Federal do Paraná, C.P. 19044, 81531-990 Curitiba-PR, Brazil.
    Modeling bilayer polymer/fullerene photovoltaic devices2004In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 96, no 1, p. 40-43Article in journal (Refereed)
    Abstract [en]

    The electrical transport and charge generation of polymer/fullerene photovoltaic devices were investigated. The polymer/fullerene photodiodes were formed by a heterojunction of fullerene and a semiconducting polymer poly (3,4-ethylenedioxythiophene). The current-voltage characteristic of the devices were measured with variable thickness of the C60 layer, under monochromatic light of different wavelengths. The results show that the values of the electrical photoconductivity are related to the optical absorption coefficient of the fullerene, and thus implying a large contribution of the C60 films to the diode photocurrent.

  • 218.
    Koehler, M.
    et al.
    Nonlinear Optics Laboratory, Institute of Quantum Electronics, Swiss Federal Institute of Technology, CH-8093 Zürich, Switzerland.
    Roman, L.S.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Da, Luz M.G.E.
    Da Luz, M.G.E., Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-990 Curitiba-PR, Brazil.
    Space-charge-limited bipolar currents in polymer/C60 diodes2002In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 92, no 9, p. 5575-Article in journal (Refereed)
    Abstract [en]

    [No abstract available]

  • 219.
    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.

  • 220.
    Kroon, Renee
    et al.
    University of S Australia, Australia Chalmers, Sweden .
    Diaz de Zerio Mendaza, Amaia
    Chalmers, Sweden .
    Himmelberger, Scott
    Stanford University, CA 94305 USA .
    Bergqvist, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Backe, Olof
    Chalmers, Sweden .
    Couto Faria, Gregorio
    Stanford University, CA 94305 USA University of Sao Paulo, Brazil .
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Obaid, Abdulmalik
    Wake Forest University, NC 27106 USA .
    Zhuang, Wenliu
    Chalmers, Sweden .
    Gedefaw, Desta
    Chalmers, Sweden .
    Olsson, Eva
    Chalmers, Sweden .
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Salleo, Alberto
    Stanford University, CA 94305 USA .
    Muller, Christian
    Chalmers, Sweden .
    Andersson, Mats R.
    University of S Australia, Australia Chalmers, Sweden .
    A New Tetracyclic Lactam Building Block for Thick, Broad-Bandgap Photovoltaics2014In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 136, no 33, p. 11578-11581Article in journal (Refereed)
    Abstract [en]

    A new tetracyclic lactam building block for polymer semiconductors is reported that was designed to combine the many favorable properties that larger fused and/or amide-containing building blocks can induce, including improved solid-state packing, high charge carrier mobility, and improved charge separation. Copolymerization with thiophene resulted in a semicrystalline conjugated polymer, PTNT, with a broad bandgap of 2.2 eV. Grazing incidence wide-angle X-ray scattering of PTNT thin films revealed a strong tendency for face-on pi-stacking of the polymer backbone, which was retained in PTNT:firllerene blends. Corresponding solar cells featured a high open-circuit voltage of 0.9 V, a fill factor around 0.6, and a power conversion efficiency as high as 596 for greater than200 nm thick active layers, regardless of variations in blend stoichiometry and nanostructure. Moreover, efficiencies of greater than4% could be retained when thick active layers of similar to 400 rim were employed. Overall, these values are the highest reported for a conjugated polymer with such a broad bandgap and are unprecedented in materials for tandem and particularly ternary blend photovoltaics. Hence, the newly developed tetracyclic lactam unit has significant potential as a conjugated building block in future organic electronic materials.

  • 221.
    Kroon, Renee
    et al.
    University of S Australia, Australia; Chalmers, Sweden.
    Melianas, Armantas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhuang, Wenliu
    Chalmers, Sweden.
    Bergqvist, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Diaz de Zerio Mendaza, Amaia
    Chalmers, Sweden.
    Steckler, Timothy T.
    Chalmers, Sweden.
    Yu, Liyang
    King Abdullah University of Science and Technology, Saudi Arabia.
    Bradley, Siobhan J.
    University of S Australia, Australia.
    Musumeci, Chiara
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Gedefaw, Desta
    Chalmers, Sweden.
    Nann, Thomas
    University of S Australia, Australia.
    Amassian, Aram
    King Abdullah University of Science and Technology, Saudi Arabia.
    Muller, Christian
    Chalmers, Sweden.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Andersson, Mats R.
    University of S Australia, Australia; Chalmers, Sweden.
    Comparison of selenophene and thienothiophene incorporation into pentacyclic lactam-based conjugated polymers for organic solar cells2015In: Polymer Chemistry, ISSN 1759-9954, E-ISSN 1759-9962, Vol. 6, no 42, p. 7402-7409Article in journal (Refereed)
    Abstract [en]

    In this work, we compare the effect of incorporating selenophene versus thienothiophene spacers into pentacyclic lactam-based conjugated polymers for organic solar cells. The two cyclic lactam-based copolymers were obtained via a new synthetic method for the lactam moiety. Selenophene incorporation results in a broader and red-shifted optical absorption while retaining a deep highest occupied molecular orbital level, whereas thienothienophene incorporation results in a blue-shifted optical absorption. Additionally, grazing-incidence wide angle X-ray scattering data indicates edge- and face-on solid state order for the selenophene-based polymer as compared to the thienothiophene-based polymer, which orders predominantly edge-on with respect to the substrate. In polymer : PC71BM bulk heterojunction solar cells both materials show a similar open-circuit voltage of similar to 0.80-0.84 V, however the selenophene-based polymer displays a higher fill factor of similar to 0.70 vs. similar to 0.65. This is due to the partial face-on backbone orientation of the selenophene-based polymer, leading to a higher hole mobility, as confirmed by single-carrier diode measurements, and a concomitantly higher fill factor. Combined with improved spectral coverage of the selenophene-based polymer, as confirmed by quantum efficiency experiments, it offers a larger short-circuit current density of similar to 12 mA cm(-2). Despite the relatively low molecular weight of both materials, a very robust power conversion efficiency similar to 7% is achieved for the selenophene-based polymer, while the thienothiophene-based polymer demonstrates only a moderate maximum PCE of similar to 5.5%. Hence, the favorable effects of selenophene incorporation on the photovoltaic performance of pentacyclic lactam-based conjugated polymers are clearly demonstrated.

  • 222. Lacic, Sasa
    et al.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Modeling electrical transport in blend heterojunction organic solar cells2005In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 97, p. 12490-1-142490-7Article in journal (Refereed)
  • 223.
    Li, Wei
    et al.
    Chalmers, Sweden; S China University of Technology, Peoples R China.
    Wang, Daojuan
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Wang, Suhao
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Ma, Wei
    Xi An Jiao Tong University, Peoples R China.
    Hedstrom, Svante
    Lund University, Sweden.
    Ian James, David
    Chalmers, Sweden.
    Xu, Xiaofeng
    Chalmers, Sweden.
    Persson, Petter
    Lund University, Sweden.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Huang, Fei
    S China University of Technology, Peoples R China.
    Wang, Ergang
    Chalmers, Sweden.
    One-Step Synthesis of Precursor Oligomers for Organic Photovoltaics: A Comparative Study between Polymers and Small Molecules2015In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 49, p. 27106-27114Article in journal (Refereed)
    Abstract [en]

    Two series of oligomers TQ and rhodanine end-capped TQ-DR were synthesized using a facile one-step method. Their optical, electrical, and thermal properties and photovoltaic performances were systematically investigated and compared. The TQ series of oligomers were found to be amorphous, whereas the TQ-DR series are semicrystalline. For the TQ oligomers, the results obtained in solar cells show that as the chain length of the oligomers increases, an increase in power conversion efficiency (PCE) is obtained. However, when introducing 3-ethylrhodanine into the TQ oligomers as end groups, the PCE of the TQ-DR series of oligomers decreases as the chain length increases. Moreover, the TQ-DR series of oligomers give much higher performances compared to the original amorphous TQ series of oligomers owing to the improved extinction coefficient (epsilon) and crystallinity afforded by the rhodanine. In particular, the highly crystalline oligomer TQ5-DR, which has the shortest conjugation length shows a high hole mobility of 0.034 cm(2) V-1 s(-1) and a high PCE of 3.14%, which is the highest efficiency out of all of the six oligomers. The structure-property correlations for all of the oligomers and the TQ1 polymer demonstrate that structural control of enhanced intermolecular interactions and crystallinity is a key for small molecules/oligomers to achieve high mobilities, which is an essential requirement for use in OPVs.

  • 224.
    Li, Weiwei
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhou, Yi
    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.
    Andersson, Mattias
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Thomann, Yi
    Freiburg Material Research Centre, Germany.
    Veit, Clemens
    Fraunhofer Institute for Solar Energy Systems, Germany.
    Tvingstedt, Kristofer
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Qin, Ruiping
    Beijing Normal University, China.
    Bo, Zhishan
    Beijing Normal University, China.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Wuerfel, Uli
    Freiburg Material Research Centre, Germany.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    The Effect of additive on performance and shelf-stability of HSX-1/PCBM photovoltaic devices2011In: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 12, no 9, p. 1544-1551Article in journal (Refereed)
    Abstract [en]

    How 1,8-diiodooctane (DIO) enhances performance of polymer solar cells based on polymer HXS-1 and fullerene [6,6]-phenyl C(71)-butyric acid methyl ester (PC(71)BM) from 3.6% to 5.4% is scrutinized with several techniques by comparing devices or blend films spin-coated from dichlorobenzene (DCB) to those from DCB/DIO (97.5:2.5 v/v). Morphology of blend films is examined with atomic force microscopy (AFM), transmission electron microscopy (TEM) and electron tomography (3-D TEM), respectively. Charge generation and recombination is studied with photoluminescence, and charge transport with field effect transistors. The morphology with domain size in 10-20 nm and vertical elongated clusters formed in DIO system is supposed to facilitate charge transport and minimize charge carrier recombination, which are the main reasons for enhancing power conversion efficiency (PCE) from 3.6% (without DIO) to 5.4% (with DIO). Furthermore, a two year inspection shows no significant impact of DIO on the shelf-stability of the solar cells. No visible degradation in the second year indicates that the morphology of the active layers in the devices is relatively stable after initial relaxation in the first year.

  • 225.
    Li, Yongxi
    et al.
    Soochow University, Peoples R China; Soochow University, Peoples R China; Chinese Academic Science, Peoples R China.
    Liu, Xiaodong
    Soochow University, Peoples R China.
    Wu, Fu-Peng
    Soochow University, Peoples R China.
    Zhou, Yi
    Soochow University, Peoples R China.
    Jiang, Zuo-Quan
    Soochow University, Peoples R China.
    Song, Bo
    Soochow University, Peoples R China.
    Xia, Yuxin
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhang, Zhi-Guo
    Chinese Academic Science, Peoples R China.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Li, Yongfang
    Soochow University, Peoples R China; Soochow University, Peoples R China; Chinese Academic Science, Peoples R China.
    Liao, Liang-Sheng
    Soochow University, Peoples R China.
    Non-fullerene acceptor with low energy loss and high external quantum efficiency: towards high performance polymer solar cells2016In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 16, p. 5890-5897Article in journal (Refereed)
    Abstract [en]

    A non-fullerene electron acceptor bearing a fused 10-heterocyclic ring (indacenodithiophenoindacenodithiophene) with a narrow band gap (similar to 1.5 eV) was designed and synthesized. It possesses excellent planarity and enhanced effective conjugation length compared to previously reported fused-ring electron acceptors. When this acceptor was paired with PTB7-Th and applied in polymer solar cells, a power conversion efficiency of 6.5% was achieved with a high open circuit voltage of 0.94 V. More significantly, an energy loss as low as 0.59 eV and an external quantum efficiency as high as 63% were obtained simultaneously.

  • 226.
    Lindgren, Lars
    et al.
    Chalmers University of Technology.
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Admassie, Shimelis
    Addis Ababa University.
    Wang, Xiangjun
    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 .
    Andersson, M.R.
    Chalmers University of Technology.
    Blue Polymer Light-Emitting Diodes Based on Novel Polymers2005In: 14:th International Conference on Luminescence ICL05,2005, 2005Conference paper (Other academic)
  • 227.
    Lindgren, L.J.
    et al.
    Chalmers Tekniska Högskola.
    Wang, Xiangjun
    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 .
    Andersson, Mats R.
    Chalmers Tekniska Högskola.
    Synthesis and properties of polyfluorenes with phenyl substituents2005In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 154, p. 97-100Article in journal (Refereed)
  • 228.
    Lindgren, L.J
    et al.
    CTH.
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Admassie, S.
    Addis Abeba university.
    Wang, Xiangjun
    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 .
    Blue light-emitting diodes based on novel polyfluorene copolymers2007In: Journal of Luminescence, ISSN 0022-2313, E-ISSN 1872-7883, Vol. 122-123, no 1-2, p. 610-613Article in journal (Refereed)
    Abstract [en]

    This study presents the synthesis and characterisation of a series of fluorene-based conjugated copolymers, together with the preparation and characterisation of the corresponding light-emitting devices. The polymers consist of alkoxyphenyl-substituted fluorene units together with different amounts of a hole-transporting triphenylamine-substituted fluorene unit: 0%, 10%, 25% and 50%. All polymers (P0, P1, P2, and P3) show high photoluminescence efficiency (ηPL) and light emission (both PL and EL) in the blue spectral region. Electrochemical studies show improved hole injection as the ratio of the triphenylamine-substituted segment is increased. The electroluminescence quantum efficiencies (EQEs) of the devices increase six times going from P0 to P1. Compared with P1, polymers P2 and P3 show lower efficiencies in devices. These findings indicate the presence of an optimal polymer composition, where balance between the charge-carrier mobilities has been reached. © 2006 Elsevier B.V. All rights reserved.

  • 229.
    Lindgren, Mikael
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Stabo-Eeg, Frantz
    Norwegian University of Science and Technology.
    Nilsson, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Hammarström, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biochemistry. 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.
    Biosensing and -imaging with enantiomeric luminescent conjugated polythiophenes using single - and multiphoton excitation2006In: Proceedings of International Symposium on Biophotonics, Nanophotonics and Metamaterials, IEEE , 2006, p. 226-226Conference paper (Refereed)
  • 230.
    Lindqvist, Camilla
    et al.
    Chalmers, Sweden .
    Bergqvist, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Backe, Olof
    Chalmers, Sweden .
    Gustafsson, Stefan
    Chalmers, Sweden .
    Wang, Ergang
    Chalmers, Sweden .
    Olsson, Eva
    Chalmers, Sweden .
    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 University of S Australia, Australia .
    Muller, Christian
    Chalmers, Sweden .
    Fullerene mixtures enhance the thermal stability of a non-crystalline polymer solar cell blend2014In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 104, no 15, p. 153301-Article in journal (Refereed)
    Abstract [en]

    Printing of polymer: fullerene solar cells at high speed requires annealing at temperatures up to 140 degrees C. However, bulk-heterojunction blends that comprise a non-crystalline donor polymer often suffer from insufficient thermal stability and hence rapidly coarsen upon annealing above the glass transition temperature of the blend. In addition, micrometer-sized fullerene crystals grow, which are detrimental for the solar cell performance. In this manuscript, we present a strategy to limit fullerene crystallization, which is based on the use of fullerene mixtures of the two most common derivatives, PC61BM and PC71BM, as the acceptor material. Blends of this fullerene mixture and a non-crystalline thiophene-quinoxaline copolymer display considerably enhanced thermal stability and largely retain their photovoltaic performance upon annealing at elevated temperatures as high as 170 degrees C.

  • 231.
    Lindqvist, Camilla
    et al.
    Chalmers University of Technology, Göteborg, Sweden.
    Bergqvist, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Feng, Ching-Chiao
    Chalmers University of Technology, Göteborg, Sweden.
    Gustafsson, Stefan
    Chalmers University of Technology, Göteborg, Sweden.
    Backe, Olof
    Chalmers University of Technology, Göteborg, Sweden.
    Treat, Neil D.
    Imperial College London, UK.
    Bounioux, Celine
    Ben Gurion University of Negev, Israel .
    Henriksson, Patrik
    Chalmers University of Technology, Göteborg, Sweden.
    Kroon, Renee
    Chalmers University of Technology, Göteborg, Sweden.
    Wang, Ergang
    Chalmers University of Technology, Göteborg, Sweden.
    Sanz-Velasco, Anke
    Chalmers University of Technology, Göteborg, Sweden.
    Magnus Kristiansen, Per
    University of Applied Sciences and Arts Northwestern Switzerland (FHNW), Windisch, Switzerland.
    Stingelin, Natalie
    Imperial College London, UK.
    Olsson, Eva
    Chalmers University of Technology, Göteborg, Sweden.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Andersson, Mats R.
    Chalmers University of Technology, Göteborg, Sweden.
    Muller, Christian
    Chalmers University of Technology, Göteborg, Sweden.
    Fullerene Nucleating Agents: A Route Towards Thermally Stable Photovoltaic Blends2014In: Advanced Energy Materials, ISSN 1614-6832, Vol. 4, no 9, article id 1301437Article in journal (Refereed)
    Abstract [en]

    The bulk-heterojunction nanostructure of non-crystalline polymer: fullerene blends has the tendency to rapidly coarsen when heated above its glass transition temperature, which represents an important degradation mechanism. We demonstrate that fullerene nucleating agents can be used to thermally arrest the nanostructure of photovoltaic blends that comprise a non-crystalline thiophene-quinoxaline copolymer and the widely used fullerene derivative [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM). To this end, C-60 fullerene is employed to efficiently nucleate PCBM crystallization. Sub-micrometer-sized fullerene crystals are formed when as little as 2 wt% C-60 with respect to PCBM is added to the blend. These reach an average size of only 200 nanometers upon introduction of more than 8 wt% C-60. Solar cells based on C-60-nucleated blends indicate significantly improved thermal stability of the bulk-heterojunction nanostructure even after annealing at an elevated temperature of 130 degrees C, which lies above the glass transition temperature of the blend. Moreover, we find that various other compounds, including C-70 fullerene, single-walled carbon nanotubes, and sodium benzoate, as well as a number of commercial nucleating agents-commonly used to clarify isotactic polypropylene-permit to control crystallization of the fullerene phase.

  • 232.
    Lorrmann, J
    et al.
    University Wurzburg.
    Badada, B H
    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.
    Dyakonov, V
    University Wurzburg.
    Deibel, C
    University Wurzburg.
    Charge carrier extraction by linearly increasing voltage: Analytic framework and ambipolar transients2010In: JOURNAL OF APPLIED PHYSICS, ISSN 0021-8979, Vol. 108, no 11, p. 113705-Article in journal (Refereed)
    Abstract [en]

    Up to now the basic theoretical description of charge extraction by linearly increasing voltage (CELIV) is solved for a low conductivity approximation only. Here we present the full analytical solution, thus generalize the theoretical framework for this method. We compare the analytical solution and the approximated theory, showing that especially for typical organic solar cell materials the latter approach has a very limited validity. Photo-CELIV measurements on poly(3-hexyl thiophene-2,5-diyl):[6,6]-phenyl-C-61 butyric acid methyl ester based solar cells were then evaluated by fitting the current transients to the analytical solution. We found that the fit results are in a very good agreement with the experimental observations, if ambipolar transport is taken into account, the origin of which we will discuss. Furthermore we present parametric equations for the mobility and the charge carrier density, which can be applied over the entire experimental range of parameters.

  • 233.
    Ma, Zaifei
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Dang, Dongfeng
    Chalmers, Sweden Xiangtan University, Peoples R China .
    Tang, Zheng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Gedefaw, Desta
    Chalmers, Sweden .
    Bergqvist, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Zhu, Weiguo
    Xiangtan University, Peoples R China .
    Mammo, Wendimagegn
    University of Addis Ababa, Ethiopia .
    Andersson, Mats R.
    Chalmers, Sweden .
    Inganäs, Olle
    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.
    Wang, Ergang
    Chalmers, Sweden .
    A Facile Method to Enhance Photovoltaic Performance of Benzodithiophene-Isoindigo Polymers by Inserting Bithiophene Spacer2014In: ADVANCED ENERGY MATERIALS, ISSN 1614-6832, Vol. 4, no 6Article in journal (Refereed)
    Abstract [en]

    A series of conjugated polymers containing benzodithiophene as donor and isoindigo as acceptor with no, one, two and three thiophene spacer groups is synthesized and characterized. The polymer with bithiophene as a spacer has a superior efficiency of 7.31% in solar cells. This demonstrates an important design strategy to produce polymers for high-performance solar cells by inserting thiophene spacer groups.

  • 234.
    Ma, Zaifei
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Sun, Wenjun
    Department of Chemical and Biological Engineering/Polymer Technology, Chalmers University of Technology, Göteborg, Sweden.
    Himmelberger, Scott
    Department of Material Science and Engineering, Stanford University, USA.
    Vandewal, Koen
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Tang, Zheng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Bergqvist, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Salleo, Alberto
    Department of Material Science and Engineering, Stanford University, USA.
    Wenzel Andreasen, Jens
    Imaging and Structural Analysis Programme, Department of Energy Conversion and Storage, Technical University of Denmark, Denmark.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Andersson, Mats R
    Department of Chemical and Biological Engineering/Polymer Technology, Chalmers University of Technology, Sweden.
    Müller, Christian
    Department of Chemical and Biological Engineering/Polymer Technology, Chalmers University of Technology, Sweden.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Wang, Ergang
    Chalmers, Sweden .
    Structure-Property Relationships of Oligothiophene-Isoindigo Polymers for Efficient Bulk-Heterojunction Solar Cells2014In: energy and environmental science, ISSN 1754-5692, Vol. 17, no 1, p. 361-369Article in journal (Refereed)
    Abstract [en]

    A series of alternating oligothiophene (nT)-isoindigo (I) copolymers (PnTI) were synthesized to investigate the influence of the oligothiophene block length on the photovoltaic (PV) properties of PnTI:PCBM bulk-heterojunction blends. Our study indicates that the number of thiophene rings (n) in the repeating unit alters both, polymer crystallinity and polymer-fullerene interfacial energetics, which results in a decreasing open-circuit voltage (Voc) of the solar cells with increasing n. The short-circuit current density (Jsc) of P1TI:PCBM devices is limited by the absence of a significant driving force for electron transfer. Instead, blends based on P5TI and P6TI feature large polymer domains, which limit charge generation and thus Jsc. The best PV performance with a power conversion efficiency of up to 6.9% was achieved with devices based on P3TI, where a combination of favorable morphology and optimal interface energy level offset ensures efficient exciton separation and charge generation. The structure-property relationship demonstrated in this work is a valuable guideline for the design of high performance polymers with small energy losses during the charge generation process, allowing for the fabrication of efficient solar cells that combine a minimal loss in Voc with a high Jsc.

  • 235.
    Ma, Zaifei
    et al.
    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, Ergang
    Chalmers, Sweden .
    Andersson, Mats R
    Chalmers, Sweden .
    Inganäs, Olle
    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.
    Influences of Surface Roughness of ZnO Electron Transport Layer on the Photovoltaic Performance of Organic Inverted Solar Cells2012In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 116, no 46, p. 24462-24468Article in journal (Refereed)
    Abstract [en]

    Here, we demonstrate the correlation between the surface roughness of the ZnO interlayer used as an electron transporting interlayer (ETL) in organic inverted solar cells (ISCs) and the photovoltaic performance of the ISCs. Three different surfaces of the ZnO ETL are studied in ISCs with the polymer poly[2,3-bis-(3-octyloxyphenyl)-quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl] (TQ1) mixed with [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) as the active layer. The results obtained from these ISCs show that power conversion efficiency increases from 2.7% to 3.9% when the root-mean-square roughness of the ZnO layer decreases from 48 to 1.9 nm. Moreover, it is found that the short-circuit current density is higher in the ISC based on the smoother ZnO interlayer, with a larger donor/acceptor (D/A) interfacial area in the active layer that facilitates exciton dissociation. The reduced effective interfacial area between the photoactive layer and the ZnO interlayer with decreased ZnO surface roughness leads to an observed improvement in both fill factor and open circuit voltage, which is ascribed to a reduced concentration of traps at the interface between the ZnO interlayer and the active layer.

  • 236.
    Ma, Zaifei
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Wang, Ergang
    Chalmers.
    Jarvid, Markus E
    Chalmers.
    Henriksson, Patrik
    Chalmers.
    Inganäs, Olle
    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.
    Synthesis and characterization of benzodithiophene-isoindigo polymers for solar cells2012In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, no 5, p. 2306-2314Article in journal (Refereed)
    Abstract [en]

    Three new alternating polymers with the electron-deficient isoindigo group as the acceptor unit and benzo[1,2-b:4,5-b] dithiophene (BDT) or BDT flanked by thiophenes (or octylthiophenes) as the donor unit were designed and synthesized. All the polymers have good thermal stability, solubility and broad absorption spectra. Their photophysical, electrochemical and photovoltaic (PV) properties were investigated. To understand their different PV performance in the resulting polymer solar cells (PSCs), the morphology of their blends with fullerene derivatives was investigated by atomic force microscopy, and the molecular geometries as well as the molecular frontier orbitals were simulated by density functional theory calculations (Gaussian 09). The polymer PBDT-TIT, with BDT flanked by thiophenes as the donor unit and isoindigo as the acceptor unit, exhibits quite planar backbones and its blend with fullerene derivatives shows optimal morphology. As a result, the PSCs based on PBDT-TIT with a conventional device configuration of ITO/PEDOT: PSS/PBDT-TIT: PC(61)BM/LiF/Al showed a power conversion efficiency of 4.22%, with a short-circuit current density of 7.87 mA cm(-2), an open-circuit voltage of 0.79 V and a fill factor of 0.68 under the AM 1.5G illumination with an intensity of 100 mW cm(-2) from a solar simulator.

  • 237.
    Mammo, W.
    et al.
    CTH.
    Admassie, S.
    Addis Abeba university.
    Gadisa, Abay
    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 .
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Andersson, m.R
    CTH.
    New low band gap alternating polyfluorene copolymer-based photovoltaic cells2007In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 91, no 11, p. 1010-1018Article in journal (Refereed)
    Abstract [en]

    New low band gap alternating polyfluorene copolymers were synthesized for use in plastic solar cells and their optical, electrochemical, and photovoltaic characteristics were determined. These polymers incorporated fluorene units alternating with groups including electron-withdrawing (A) and electron-donating (D) groups in donor-acceptor-donor (DAD) sequence to achieve the lowering of band gaps. The HOMO-LUMO values were estimated from electrochemical studies. By varying the donor and acceptor strength and position of the solubilizing substituents, similar HOMO values were obtained. These values were also found to correlate well with the open circuit voltage (VOC) values determined from photovoltaic data of the polymers blended with the acceptor PCBM. Despite similar HOMO values, the absorption spectra of the polymers differ significantly. This prompted the preparation of photovoltaic devices consisting of blends of two polymers with complementary absorptions in combination with PCBM to harvest more photons in the polymer solar cells. © 2007 Elsevier B.V. All rights reserved.

  • 238.
    Mastria, Rosanna
    et al.
    CNR NANOTEC Ist Nanotecnol, Italy; University of Salento, Italy.
    Rizzo, Aurora
    CNR NANOTEC Ist Nanotecnol, Italy.
    Giansante, Carlo
    CNR NANOTEC Ist Nanotecnol, Italy; UNILE, Italy.
    Ballarini, Dario
    CNR NANOTEC Ist Nanotecnol, Italy.
    Dominici, Lorenzo
    CNR NANOTEC Ist Nanotecnol, Italy; UNILE, Italy.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Gigli, Giuseppe
    CNR NANOTEC Ist Nanotecnol, Italy; University of Salento, Italy.
    Role of Polymer in Hybrid Polymer/PbS Quantum Dot Solar Cells2015In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 119, no 27, p. 14972-14979Article in journal (Refereed)
    Abstract [en]

    Hybrid nanocomposites (HCs) obtained by blend solutions of conjugated polymers and colloidal semiconductor nanocrystals are among the most promising materials to be exploited in solution-processed photovoltaic applications. The comprehension of the operating principles of solar cells based on HCs thus represents a crucial step toward the rational engineering of high performing photovoltaic devices. Here we investigate the effect of conjugated polymers on hybrid solar cell performances by taking advantage from an optimized morphology of the HCs comprising lead sulfide quantum dots (PbS QDs). Uncommonly, we find that larger photocurrent densities are achieved by HCs incorporating wide-bandgap polymers. A combination of spectroscopic and electro-optical measurements suggests that wide-bandgap polymers promote efficient charge/exciton transfer processes and hinder the population of midgap states on PbS QDs. Our linings underline the key role of the polymer in HC-based solar cells in the activation/deactivation of charge transfer/loss pathways.

  • 239.
    Melianas, Armantas
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Etzold, Fabian
    Max Planck Institute Polymer Research, Germany.
    Savenije, Tom J.
    Delft University of Technology, Netherlands.
    Laquai, Frederic
    Max Planck Institute Polymer Research, Germany; King Abdullah University of Science and Technology, Saudi Arabia.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Kemerink, Martijn
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering. Eindhoven University of Technology, Netherlands.
    Photo-generated carriers lose energy during extraction from polymer-fullerene solar cells2015In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 6, no 8778Article in journal (Refereed)
    Abstract [en]

    In photovoltaic devices, the photo-generated charge carriers are typically assumed to be in thermal equilibrium with the lattice. In conventional materials, this assumption is experimentally justified as carrier thermalization completes before any significant carrier transport has occurred. Here, we demonstrate by unifying time-resolved optical and electrical experiments and Monte Carlo simulations over an exceptionally wide dynamic range that in the case of organic photovoltaic devices, this assumption is invalid. As the photo-generated carriers are transported to the electrodes, a substantial amount of their energy is lost by continuous thermalization in the disorder broadened density of states. Since thermalization occurs downward in energy, carrier motion is boosted by this process, leading to a time-dependent carrier mobility as confirmed by direct experiments. We identify the time and distance scales relevant for carrier extraction and show that the photo-generated carriers are extracted from the operating device before reaching thermal equilibrium.

  • 240.
    Melianas, Armantas
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Pranculis, Vytenis
    Center for Physical Sciences and Technology, Lithuania.
    Devižis, Andrius
    Center for Physical Sciences and Technology, Lithuania.
    Gulbinas, Vidmantas
    Center for Physical Sciences and Technology, Lithuania.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Kemerink, Martijn
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, The Institute of Technology. Department of Applied Physics, Eindhoven University of Technology, MB, Eindhoven, The Netherlands.
    Dispersion-Dominated Photocurrent in Polymer:Fullerene Solar Cells2014In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 24, no 28, p. 4507-4514Article in journal (Refereed)
    Abstract [en]

    Organic bulk heterojunction solar cells are often regarded as near-equilibrium devices, whose kinetics are set by well-defined charge carrier mobilities, and relaxation in the density of states is commonly ignored or included purely phenomenologically. Here, the motion of photocreated charges is studied experimentally with picosecond time resolution by a combination of time-resolved optical probing of electric field and photocurrent measurements, and the data are used to define parameters for kinetic Monte Carlo modelling. The results show that charge carrier motion in a prototypical polymer:fullerene solar cell under operational conditions is orders of magnitude faster than would be expected on the basis of corresponding near-equilibrium mobilities, and is extremely dispersive. There is no unique mobility. The distribution of extraction times of photocreated charges in operating organic solar cells can be experimentally determined from the charge collection transients measured under pulsed excitation. Finally, a remarkable distribution of the photocurrent over energy is found, in which the most relaxed charge carriers in fact counteract the net photocurrent.

  • 241.
    Melianas, Armantas
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Pranculis, Vytenis
    Center for Physical Sciences and Technology, Vilnius, Lithuania.
    Spoltore, Donato
    Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Dresden, Germany.
    Benduhn, Johannes
    Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Dresden, Germany.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Gulbinas, Vidmantas
    Center for Physical Sciences and Technology, Vilnius, Lithuania / Department of General Physics and Spectroscopy, Faculty of Physics, Vilnius University, Vilnius, Lithuania.
    Vandewal, Koen
    Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) and Institute for Applied Physics, Technische Universität Dresden, Dresden, Germany.
    Kemerink, Martijn
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering.
    Charge Transport in Pure and Mixed Phases in Organic Solar Cells2017In: Advanced Energy Materials, ISSN 1614-6840, Vol. 7, no 20Article in journal (Refereed)
    Abstract [en]

    In organic solar cells continuous donor and acceptor networks are considered necessary for charge extraction, whereas discontinuous neat phases and molecularly mixed donor–acceptor phases are generally regarded as detrimental. However, the impact of different levels of domain continuity, purity, and donor–acceptor mixing on charge transport remains only semiquantitatively described. Here, cosublimed donor–acceptor mixtures, where the distance between the donor sites is varied in a controlled manner from homogeneously diluted donor sites to a continuous donor network are studied. Using transient measurements, spanning from sub-picoseconds to microseconds photogenerated charge motion is measured in complete photovoltaic devices, to show that even highly diluted donor sites (5.7%–10% molar) in a buckminsterfullerene matrix enable hole transport. Hopping between isolated donor sites can occur by long-range hole tunneling through several buckminsterfullerene molecules, over distances of up to ≈4 nm. Hence, these results question the relevance of “pristine” phases and whether a continuous interpenetrating donor–acceptor network is the ideal morphology for charge transport.

  • 242.
    Milczarek, Grzegorz
    et al.
    Poznan Technical University.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Renewable Cathode Materials from Biopolymer/Conjugated Polymer Interpenetrating Networks2012In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 335, no 6075, p. 1468-1471Article in journal (Refereed)
    Abstract [en]

    Renewable and cheap materials in electrodes could meet the need for low-cost, intermittent electrical energy storage in a renewable energy system if sufficient charge density is obtained. Brown liquor, the waste product from paper processing, contains lignin derivatives. Polymer cathodes can be prepared by electrochemical oxidation of pyrrole to polypyrrole in solutions of lignin derivatives. The quinone group in lignin is used for electron and proton storage and exchange during redox cycling, thus combining charge storage in lignin and polypyrrole in an interpenetrating polypyrrole/lignin composite.

  • 243.
    Molla, Shimelis
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. University of Addis Ababa, Ethiopia.
    Elfwing, Anders
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Electrochemical Synthesis and Characterization of Interpenetrating Networks of Conducting Polymers for Enhanced Charge Storage2016In: ADVANCED MATERIALS INTERFACES, ISSN 2196-7350, Vol. 3, no 10, p. 1500533-Article in journal (Refereed)
    Abstract [en]

    A supercapacitor electrode consisting of an interpenetrating network of poly(aminoanthraquinone) (PAAQ) and poly(3,4-ethylenedioxythiophene) (PEDOT) is synthesized by a simple two-step galvanostatic deposition and characterized by electrochemical methods. By electrodepositing PEDOT on top of PAAQ, it is possible to access the quinones in PAAQ and as a result the specific capacitance of PAAQ increases from 90 to 383 F g(-1) and also significantly improves the charge-storage capacity from 25 to 106 mAh g(-1) at a discharge current of 1 A g(-1). These values are also significantly higher than most reported values for PEDOT and hybrids. Moreover, the hybrid material shows excellent stability with 91% of the initial capacitance being retained after 2000 cycles at a discharge rate of 2 A g(-1).

  • 244.
    Molla, Shimelis
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, Faculty of Science & Engineering. University of Addis Ababa, Ethiopia.
    Elfwing, Anders
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Skallberg, Andreas
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Extracting metal ions from water with redox active biopolymer electrodes2015In: ENVIRONMENTAL SCIENCE-WATER RESEARCH and TECHNOLOGY, ISSN 2053-1400, Vol. 1, no 3, p. 326-331Article in journal (Refereed)
    Abstract [en]

    Renewable, environmentally friendly and cheap materials like lignin and cellulose have been considered as promising materials for use in energy storage technologies. Here, we report a new application for biopolymer electrodes where they can also be simultaneously used as ion pumps to purify industrial wastewater and drinking water contaminated with toxic metals. A ternary composite film consisting of a conducting polymer polypyrrole (PPy), biopolymer lignin (LG) and anthraquinonesulfonate (AQS) was synthesized by one-step galvanostatic polymerization from an aqueous electrolyte solution. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) techniques revealed that lead ions can be extracted from a neutral aqueous solution containing lead ions by applying a potential, and can be released into another solution by reversing the polarity of the applied potential. Electrochemical quartz crystal microbalance was used to quantify the amount of metal ions that can be extracted and released.

  • 245.
    Muller, Christian
    et al.
    Esfera UAB.
    Bergqvist, Jonas
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Vandewal, Koen
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Tvingstedt, Kristofer
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Anselmo, Ana Sofia
    Karlstads University.
    Magnusson, Roger
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Applied Optics .
    Alonso, M .Isabel
    Esfera UAB.
    Moons, Ellen
    Karlstads University.
    Arwin, Hans
    Linköping University, Department of Physics, Chemistry and Biology, Applied Optics . Linköping University, The Institute of Technology.
    Campoy-Quiles, Mariano
    Esfera UAB.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Phase behaviour of liquid-crystalline polymer/fullerene organic photovoltaic blends: thermal stability and miscibility2011In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 21, no 29, p. 10676-10684Article in journal (Refereed)
    Abstract [en]

    The thermal behaviour of an organic photovoltaic (OPV) binary system comprised of a liquid-crystalline fluorene-based polymer and a fullerene derivative is investigated. We employ variable-temperature ellipsometry complemented by photo-and electroluminescence spectroscopy as well as optical microscopy and scanning force nanoscopy to explore phase transitions of blend thin films. The high glass transition temperature correlates with the good thermal stability of solar cells based on these materials. Furthermore, we observe partial miscibility of the donor and acceptor together with the tendency of excess fullerene derivative to segregate into exceedingly large domains. Thus, for charge generation less adequate bulk-heterojunction nanostructures are poised to develop if this mixture is exposed to more elevated temperatures. Gratifyingly, the solubility of the fullerene derivative in the polymer phase is found to decrease if a higher molecular-weight polymer fraction is employed, which offers routes towards improving the photovoltaic performance of non-crystalline OPV blends.

  • 246.
    Murthy, D H K
    et al.
    Delft University of Technology, Netherlands .
    Melianas, Armantas
    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.
    Juska, Gytis
    Vilnius University, Lithuania .
    Arlauskas, Kestutis
    Vilnius University, Lithuania .
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Siebbeles, Laurens D A
    Delft University of Technology, Netherlands .
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Savenije, Tom J
    Delft University of Technology, Netherlands .
    Origin of Reduced Bimolecular Recombination in Blends of Conjugated Polymers and Fullerenes2013In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 23, no 34, p. 4262-4268Article in journal (Refereed)
    Abstract [en]

    Bimolecular charge carrier recombination in blends of a conjugated copolymer based on a thiophene and quinoxaline (TQ1) with a fullerene derivative ((6,6)-phenyl-C-71-butyric acidmethyl ester, PC71BM) is studied by two complementary techniques. TRMC (time-resolved microwave conductance) monitors the conductance of photogenerated mobile charge carriers locally on a timescale of nanoseconds, while using photo-CELIV (charge extraction by linearly increasing voltage) charge carrier dynamics are monitored on a macroscopic scale and over tens of microseconds. Despite these significant differences in the length and time scales, both techniques show a reduced Langevin recombination with a prefactor close to 0.05. For TQ1:PC71BM blends, the value is independent of temperature. On comparing TRMC data with electroluminescence measurements it is concluded that the encounter complex and the charge transfer state have very similar energetic properties. The value for annealed poly(3-hexylthiophene) (P3HT):(6,6)-phenyl-C-61-butyric acid methyl ester (PC61BM) is approximately 10(-4), while for blend systems containing an amorphous polymer values are close to 1. These large differences can be related to the extent of charge delocalization of opposite charges in an encounter complex. Insight is provided into factors governing the bimolecular recombination process, which forms a major loss mechanism limiting the efficiency of polymer solar cells.

  • 247.
    Müller, Christian
    et al.
    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.
    Pena-Rodriguez, Ovidio
    Esfera UAB, Spain .
    Garriga, Miquel
    Esfera UAB, Spain .
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Campoy-Quiles, Mariano
    Esfera UAB, Spain .
    Determination of Thermal Transition Depth Profiles in Polymer Semiconductor Films with Ellipsometry2013In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 46, no 18, p. 7325-7331Article in journal (Refereed)
    Abstract [en]

    Geometric confinement and interface effects can significantly alter the thermodynamic properties of thin polymer films. Phase transition temperatures have been shown to strongly depend on film thickness below a critical thickness threshold. It has been suggested that this behavior is due to an interface-induced continuous variation in phase transition 200 temperatures throughout the depth of the films. Here we employ variable-temperature spectroscopic ellipsometry to demonstrate the existence of these depth profiles. We examine four different polymer semiconductors that are of interest for organic light-emitting diodes, solar cells, and field-effect transistors. In contrast to insulating polymers, these light-absorbing materials provide detailed information about structural changes as a function of depth due to wavelength-dependent attenuation. This concept enables us to investigate a broad range of thermodynamic processes including the glass transition, crystallization as well as crystalline and liquid-crystalline melting. In general, for the here investigated systems, higher transition temperatures are found at the free surface. Finally, the deduced profiles are used to predict the thickness dependence of the mean phase transition temperature.

  • 248.
    Müller, Christian
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Esmaeili, Morteza
    Norwegian University of Science and Technology, Norway .
    Riekel, Christian
    European Synchrotron Radiat Facil, France .
    Breiby, Dag W.
    Norwegian University of Science and Technology, Norway .
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Micro X-ray diffraction mapping of a fluorene copolymer fibre2013In: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 54, no 2, p. 805-811Article in journal (Refereed)
    Abstract [en]

    Using raster-scanning wide-angle X-ray scattering, we investigate oriented fibres of the low bandgap conjugated polymer, poly[2,7-(9,9-dioctylfluorene)-alt-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)] (F8TBT), that was developed in particular for polymer solar cells. For the first time, structural data are provided for F8TBT. Our results demonstrate that the nano-scale structure of this polymer is closely related to the externally observable features of the fibre, and thus emphasise the importance of having full control over the local molecular conformation. Liquid-crystalline phases are observed at elevated temperatures, and the molecular alignment in the drawn fibres yields scattering patterns that are dominated by broad peaks of equatorial diffuse scattering. The significant degree of preferred orientation facilitates the analysis, leading to estimates of (average) nearest-neighbour packing distances and coherence length of this macromolecule. In particular, we observe a pronounced broad signal assigned to packing of the conjugated backbone with an approximate spacing of 4.00-4.39 angstrom that is coherent over 5-6 polymer segments.

  • 249.
    Müller, Christian
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Hamedi, Mahiar
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Karlsson, Roger
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Jansson, Ronnie
    Biomed Centre, SLU.
    Marcilla, Rebeca
    CIDETEC Centre Electrochem Technology.
    Hedhammar, My
    Biomed Centre, SLU.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Woven Electrochemical Transistors on Silk Fibers2011In: ADVANCED MATERIALS, ISSN 0935-9648, Vol. 23, no 7, p. 898-Article in journal (Refereed)
    Abstract [en]

    Woven electrochemical transistors on silk fibers from the silkworm Bombyx mori are demonstrated. This is achieved with carefully chosen electrolyte chemistry: electrically conducting silk fibers are produced by dyeing silk fibers with a conjugated polyelectrolyte and gating is accomplished by use of an electrolyte mixture composed of imidazolium-based ionic liquids.

  • 250.
    Müller, Christian
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Lyotropic phase behaviour of dilute, aqueous hen lysozyme amyloid fibril dispersions2011In: JOURNAL OF MATERIALS SCIENCE, ISSN 0022-2461, Vol. 46, no 11, p. 3687-3692Article in journal (Refereed)
    Abstract [en]

    We explore the lyotropic phase behaviour of dilute, aqueous amyloid fibril dispersions from hen egg white lysozyme with respect to protein and acid concentration in order to establish preparation protocols that provide homogeneous nematic phases. Such ordered dispersions are demonstrated to facilitate alignment of amyloid nanofibrils in thin solid films, which are utilised to structure conjugated (poly)electrolytes. In addition, the occurrence of ordered phases is found to be in good qualitative agreement with phase equilibria predicted for dispersions of rod-like particles.

2345678 201 - 250 of 410
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