liu.seSearch for publications in DiVA
Change search
Refine search result
1213141516 701 - 750 of 754
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 701.
    Zhang, Fengling
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Bijleveld, Johan
    Chalmers University.
    Perzon, Erik
    Chalmers University.
    Tvingstedt, Kristofer
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Barrau, Sophie
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Andersson , Mats R
    Chalmers University.
    High photovoltage achieved in low band gap polymer solar cells by adjusting energy levels of a polymer with the LUMOs of fullerene derivatives2008In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 18, no 45, p. 5468-5474Article in journal (Refereed)
    Abstract [en]

    Solar cells based on organic molecules or conjugated polymers attract great attention due to their unique advantages, such as low cost, and their use in flexible devices, but are still limited by their low power conversion efficiency (PCE). To improve the PCEs of polymer solar cells, more efforts have been made to increase short-circuit current (J(sc)) or open-circuit voltage (V-oc). However, the trade-off between J(sc) and V-oc in bulk heterojunctions solar cells makes it tricky to find a polymer with a low band gap to efficiently absorb photons in the visible and near infrared region of the solar spectrum, while maintaining a high V-oc in solar cells. Therefore, it is crucial to design and synthesize polymers with energy levels aligning with the LUMO (lowest unoccupied molecular orbital) of an electron acceptor to minimize the LUMO level difference between donor and acceptor to keep enough driving force for charge generation, thereby maximizing photovoltage in solar cells. Here a novel copolymer APFO-Green 9 was synthesized. Polymer solar cells based on APFO-Green 9 blended with a derivative of fullerene demonstrate high photovoltage by fine tuning the HOMO and LUMO level of APFO-Green 9. Solar cells based on APFO-Green 9 and [6,6]-phenyl-C71-butyric acid methyl ester ([70]PCBM) present a photoresponse extended to 900 nm with J(sc) of 6.5 mA cm(-2), V-oc of 0.81 V and PCE of 2.3% under illumination of AM1.5 with light intensity of 100 mW cm(-2). As a low band gap polymer with a V-oc bigger than 0.8 V, APFO-Green 9 is a promising candidate for efficient tandem solar cells.

  • 702.
    Zhang, Fengling
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Ceder, M.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics.
    Enhancing the photovoltage of polymer solar cells by using a modified cathode2007In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 19, no 14, p. 1835-1838Article in journal (Refereed)
    Abstract [en]

    A method to increase the open-circuit voltage (Voc) up to 200 mV and the power conversion efficiency (PCE) by 50%, by using a thin layer of poly(ethylene oxide) (PEO) to modify the cathode in polymer solar cells, was reported. An enhanced photocurrent of polymer solar cells by bending a small amount of PEO and LiCF3SO3 into the active layer was also demonstrated. The results show that the value of open-circuit voltage increases in all diodes with PEO by 150 to 200 mV while the fill factor (FF) increases with a decrease of the thickness of PEO. The thickness of the PEO layers on Si wafers measured by using ellipsometry shows that the thickness are 3.8 nm for 1000 rmp, 2.1 nm for 3000 rmp, and 1.4 nm for 5000 rmp. The quantitative similarity of the J-V characteristics in the dark between the diodes containing PEO and LiF shows that PEO has an analogous function in the device as LiF.

  • 703.
    Zhang, Fengling
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Gadisa, Abay
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Svensson, M.
    Mat./Surf. Chem./Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
    Andersson, M.R.
    Mat./Surf. Chem./Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
    Influence of buffer layers on the performance of polymer solar cells2004In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 84, no 19, p. 3906-3908Article in journal (Refereed)
    Abstract [en]

    The study of the influence of different anode buffer layers on the performance of solar cells based on blends of polyfluorene copolymers, acting as electron donor, and [6,6]-phenyl-C61-butyric acid methylester (PCBM), acting as electron acceptor was presented. The construction of buffer later was done from different forms of poly(3, 4-ethylenedioxythiophene) poly-(styrenesulfonate) (PEDOT-PSS). Variations in open-circuit voltage, short-circuit current and fill factor were also observed. The anode buffer layer influences the photovoltage of polymer solar cells by controlling the conditions for charge injection at the anode.

  • 704.
    Zhang, Fengling
    et al.
    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.
    Conducting and Transparent Polymer Electrodes2005In: Organic Photovoltaics: Mechanism, Materials and Devices / [ed] Sam-Shajing Sun, Niyazi Serdar Sariciftci, Boca Raton, FL, USA: CRC Press , 2005, 1, p. 479-494Chapter in book (Other academic)
    Abstract [en]

    Recently developed organic photovoltaics (OPVs) show distinct advantages over their inorganic counterparts due to their lighter weight, flexible shape, versatile materials synthesis and device fabrication schemes, and low cost in large-scale industrial production. Although many books currently exist on general concepts of PV and inorganic PV materials and devices, few are available that offer a comprehensive overview of recently fast developing organic and polymeric PV materials and devices.

    Organic Photovoltaics: Mechanisms, Materials, and Devicesfills this gap. The book provides an international perspective on the latest research in this rapidly expanding field with contributions from top experts around the world.  It presents a unified approach comprising three sections: General Overviews; Mechanisms and Modeling; and Materials and Devices. Discussions include sunlight capture, exciton diffusion and dissociation, interface properties, charge recombination and migration, and a variety of currently developing OPV materials/devices. The book also includes two forewords: one by Nobel Laureate Dr. Alan J. Heeger, and the other by Drs. Aloysius Hepp and Sheila Bailey of NASA Glenn Research Center.

    Organic Photovoltaics equips students, researchers, and engineers with knowledge of the mechanisms, materials, devices, and applications of OPVs necessary to develop cheaper, lighter, and cleaner renewable energy throughout the coming decades

  • 705.
    Zhang, Fengling
    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, Faculty of Science & Engineering.
    Zhou, Yinhua
    Huazhong University of Science and Technology, Peoples R China.
    Vandewal, Koen
    Technical University of Dresden, Germany.
    Development of polymer-fullerene solar cells2016In: NATIONAL SCIENCE REVIEW, ISSN 2095-5138, Vol. 3, no 2, p. 222-239Article, review/survey (Refereed)
    Abstract [en]

    Global efforts and synergetic interdisciplinary collaborations on solution-processed bulk-heterojunction polymer solar cells (PSCs or OPVs) made power conversion efficiencies over 10% possible. The rapid progress of the field is credited to the synthesis of a large number of novel polymers with specially tunable optoelectronic properties, a better control over the nano-morphology of photoactive blend layers, the introduction of various effective interfacial layers, new device architectures and a deeper understanding of device physics. We will review the pioneering materials for polymer-fullerene solar cells and trace the progress of concepts driving their development. We discuss the evolution of morphology control, interfacial layers and device structures fully exploring the potential of photoactive materials. In order to guide a further increase in power conversion efficiency of OPV, the current understanding of the process of free charge carrier generation and the origin of the photovoltage is summarized followed by a perspective on how to overcome the limitations for industrializing PSCs.

  • 706.
    Zhang, Fengling
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Jespersen, K.G.
    Department of Chemical Physics, Lund University, Kemicentrum, SE-22100 Lund, Sweden.
    Bjorstrom, C.
    Björström, C., Department of Physics, Karlstad University, SE-65188 Karlstad, Sweden.
    Svensson, M.
    Department of Organic Chemistry and Polymer Technology, Chalmers University of Technology, SE-41296 Göteborg, Sweden.
    Andersson, M.R.
    Department of Organic Chemistry and Polymer Technology, Chalmers University of Technology, SE-41296 Göteborg, Sweden.
    Sundstrom, V.
    Sundström, V., Department of Chemical Physics, Lund University, Kemicentrum, SE-22100 Lund, Sweden.
    Magnusson, K.
    Department of Physics, Karlstad University, SE-65188 Karlstad, Sweden.
    Moons, E.
    Department of Physics, Karlstad University, SE-65188 Karlstad, Sweden.
    Yartsev, A.
    Department of Chemical Physics, Lund University, Kemicentrum, SE-22100 Lund, Sweden.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Influence of solvent mixing on the morphology and performance of solar cells based on polyfluorene copolymer/fullerene blends2006In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 16, no 5, p. 667-674Article in journal (Refereed)
    Abstract [en]

    The influence of the solvent on the morphology and performance of polymer solar cells is investigated in devices based on blends of the polyfluorene copolymer, poly(2,7-(9,9-dioctyl-fluorene)-alt-5,5-(4',7'-di-2- thienyl-2',1',3'-benzothiadiazole)), and [6,6]-phenyl-C 61-: -butyric acid methyl ester. The blends are spin-coated from chloroform or from chloroform mixed with small amounts of xylene, toluene, or chlorobenzene. The devices are characterized under monochromatic light and solar illumination AM1.5 (AM: air mass). An enhancement of the photocurrent density is observed in diodes made from chloroform mixed with chlorobenzene, and reduced photocurrent density is observed in diodes made from chloroform mixed with xylene or toluene, compared to diodes made from neat chloroform. The open-circuit voltages are almost the same in all diodes. The surfaces of the active layers are imaged using atomic force microscopy. Height images indicate that a finer and more uniform distribution of domains corresponds to the diodes with enhanced photocurrent that are made from chloroform mixed with chlorobenzene, while a structure with larger domains is associated with the lower photocurrents in the diodes made from chloroform mixed with xylene or toluene. The influence of the morphology on the excited-state dynamics and charge generation is investigated using time-resolved spectroscopy. Fast formation of bound charge pairs followed by their conversion into free charge carriers is resolved, and excitation-intensity-dependent non-geminate recombination of free charges is observed. A significant enhancement in free-charge-carrier generation is observed on introducing chlorobenzene into chloroform. Imaging photocurrent generation from the solar cells with a light-pulse technique shows an inhomogeneous photocurrent distribution, which is related to the undulations in the thickness of the active layer. Thicker parts of the diodes yield higher photocurrent values. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.

  • 707.
    Zhang, Fengling
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Johansson, M
    Andersson, MR
    Hummelen, JC
    Linkoping Univ, IFM, S-58183 Linkoping, Sweden Chalmers Univ Technol, Dept Polymer Technol, S-41296 Gothenburg, Sweden Univ Groningen, Stratingh Inst, NL-9747 AG Groningen, Netherlands.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Polymer photovoltaic cells with conducting polymer anodes2002In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 14, no 9, p. 662-665Article in journal (Refereed)
  • 708.
    Zhang, Fengling
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Johansson, M.
    Department of Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
    Andersson, M.R.
    Department of Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
    Hummelen, J.C.
    Stratingh Institute, Materials Science Centre, University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Polymer solar cells based on MEH-PPV and PCBM2003Conference paper (Refereed)
    Abstract [en]

    Polymer solar cells based on poly(2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene(MEH-PPV) and fullerene derivative [6,6]phenyl-C61butyric acid methyl ester (PCBM) were fabricated by spin-coating. The improved performance has been achieved by blend polymer MEH-PPV with PCBM in a ratio of 1:4 by weight. The power conversion efficiency reached 1.3% under illumination of AM 1.5 with an incident power density of 78 mW/cm2 in blend single layer polymer solar cells.

  • 709.
    Zhang, Fengling
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Jonforsen, M.
    Department of Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
    Johansson, D.M.
    Department of Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
    Andersson, M.R.
    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 .
    Photodiodes and solar cells based on the n-type polymer poly(pyridopyrazine vinylene) as electron acceptor2003In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 138, no 3, p. 555-560Article in journal (Refereed)
    Abstract [en]

    The photodiodes and solar cells based on the n-type polymer poly(pyridopyrazine vinylene) as electron acceptor were discussed. It was found that the external quantum efficiency of these diodes reached 7%. The analysis showed that under low-intensity monochromatic light, the open circuit voltage reached 900 mv.

  • 710.
    Zhang, Fengling
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Lacic, Sasa
    Linköpings universitet.
    Svensson, Mattias
    Chalmers Tekniska Högskola.
    Andersson, Mats R
    Chalmers Tekniska Högskola.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Theoretical models and experimental results on the temperature dependence of polyfluorene solar cells2006In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 90, p. 1607-1614Article in journal (Refereed)
  • 711.
    Zhang, Fengling
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Mammo, W.
    Addis Ababa University.
    Andersson, M.R.
    Chalmers University of Technology.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Efficient Bilayer Low Bandgap Polymer Solar Cells2006In: European Conference on Hybrid and Organic Solar Celss ECHOS06,2006, 2006, p. N29-03-3-Conference paper (Other academic)
    Abstract [en]

       

  • 712.
    Zhang, Fengling
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Mammo, Wendimagegn
    Addis Ababa Univeristy.
    Andersson, Mattias
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Admassie, Shimelis
    Addis Ababa Univeristy.
    Andersson, Mats R
    Chalmers University of Technology.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Low-Bandgap Alternating Fluorene Copolymer/Methanofullerene Heterojunctions in Efficient Near-Infrared Polymer Solar Cells2006In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 18, p. 2169-2173Article in journal (Refereed)
  • 713.
    Zhang, Fengling
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Nyberg, Tobias
    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 .
    Conducting Polymer Nanowires and Nanodots Made with Soft Lithography2002In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 2, no 12, p. 1373-1377Article in journal (Refereed)
    Abstract [en]

    The conducting polymer poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT-PSS) was patterned by micromolding in capillaries (MIMIC), in the form of nanowires on a glass or a Si wafer. The periods of the molded nanowires were 833 or 278 nm. By applying force on top of the stamp during MIMIC, the height of these nanowires could be changed. An alternative method of preparing structured surfaces is the liquid embossing technique, used to pattern polymers deposited from dispersion. Nanowires (278 nm) and 2-D nanodots on semiconducting polymer (poly(3-(2'-methoxy-5'-octyphenyl) thiophene)) POMeOPT were also achieved by another soft lithography technique-soft-embossing. The possibility to pattern both semiconducting and metallic conjugated polymers from aqueous solutions or organic solvents on a submicron level makes it possible to use these materials in flexible optoelectronic devices where light propagation and electronic paths are defined by patterning.

  • 714.
    Zhang, Fengling
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Perzon, Erik
    Chalmers Tekniska Högskola.
    Wang, Xiangjun
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Mammo, Wendimagegn
    Chalmers Tekniska Högskola.
    Andersson, Mats R.
    Chalmers Tekniska Högskola.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Polymer Solar Cells Based on a Low-Bandgap Fluorence Copolymer and a Fullerene Derivative with Photocurrent Extended to 850 nm2005In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 15, no 5, p. 745-750Article in journal (Refereed)
  • 715.
    Zhang, Fengling
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Svensson, M
    Andersson, MR
    Maggini, M
    Linkoping Univ, IFM, SE-58183 Linkoping, Sweden Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Univ Padua, Dept Organ Chem, CNR, CMRO, I-35131 Padua, Italy.
    Bucella, S
    Linkoping Univ, IFM, SE-58183 Linkoping, Sweden Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Univ Padua, Dept Organ Chem, CNR, CMRO, I-35131 Padua, Italy.
    Menna, E
    Linkoping Univ, IFM, SE-58183 Linkoping, Sweden Chalmers Univ Technol, Dept Polymer Technol, SE-41296 Gothenburg, Sweden Univ Padua, Dept Organ Chem, CNR, CMRO, I-35131 Padua, Italy.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Soluble polythiophenes with pendant fullerene groups as double cable materials for photodiodes2001In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 13, no 24, p. 1871-+Article in journal (Refereed)
    Abstract [en]

    A novel "double cable" material for photodiodes, containing both electron- and hole-transporting functional groups, is obtained by co-polymerization of thiophenes that bear a covalently linker-bound fullerene (see Figure). Even at 14% of fullerene substitution, the order of the main polythiophene chain is not seriously disturbed.

  • 716.
    Zhang, Jiangbin
    et al.
    Univ Cambridge, England; Imperial Coll London, England.
    Kan, Bin
    Nankai Univ, Peoples R China.
    Pearson, Andrew J.
    Univ Cambridge, England.
    Parnell, Andrew J.
    Univ Sheffield, England.
    Cooper, Joshaniel F. K.
    Rutherford Appleton Lab, England.
    Liu, Xiaoke
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Univ Cambridge, England.
    Conaghan, Patrick J.
    Univ Cambridge, England.
    Hopper, Thomas R.
    Imperial Coll London, England.
    Wu, Yutian
    Univ Cambridge, England.
    Wan, Xiangjian
    Nankai Univ, Peoples R China.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Greenham, Neil C.
    Univ Cambridge, England.
    Bakulin, Artem A.
    Imperial Coll London, England.
    Chen, Yongsheng
    Nankai Univ, Peoples R China.
    Friend, Richard H.
    Univ Cambridge, England.
    Correction: Efficient non-fullerene organic solar cells employing sequentially deposited donor–acceptor layers(vol 6, pg 18225, 2018)2018In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, no 43, p. 21618-21618Article in journal (Refereed)
    Abstract [en]

    Correction for Efficient non-fullerene organic solar cells employing sequentially deposited donor-acceptor layers by Jiangbin Zhang et al., J. Mater. Chem. A, 2018, 6, 18225-18233.

    Download full text (pdf)
    fulltext
  • 717.
    Zhang, Jiangbin
    et al.
    Univ Cambridge, England; Imperial Coll London, England.
    Kan, Bin
    Nankai Univ, Peoples R China.
    Pearson, Andrew J.
    Univ Cambridge, England.
    Parnell, Andrew J.
    Univ Sheffield, England.
    Cooper, Joshaniel F. K.
    Rutherford Appleton Lab, England.
    Liu, Xiaoke
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Univ Cambridge, England.
    Conaghan, Patrick J.
    Univ Cambridge, England.
    Hopper, Thomas R.
    Imperial Coll London, England.
    Wu, Yutian
    Imperial Coll London, England.
    Wan, Xiangjian
    Nankai Univ, Peoples R China.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Greenham, Neil C.
    Univ Cambridge, England.
    Bakulin, Artem A.
    Imperial Coll London, England.
    Chen, Yongsheng
    Nankai Univ, Peoples R China.
    Friend, Richard H.
    Univ Cambridge, England.
    Efficient non-fullerene organic solar cells employing sequentially deposited donor-acceptor layers2018In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, no 37, p. 18225-18233Article in journal (Refereed)
    Abstract [en]

    Non-fullerene acceptors (NFAs) have recently outperformed their fullerene counterparts in binary bulk-heterojunction (BHJ) organic solar cells (OSCs). Further development of NFA OSCs may benefit other novel OSC device structures that alter or extend the standard BHJ concept. Here, we report such a new processing route that forms a BHJ-like morphology between sequentially processed polymer donor and NFA with high power conversion efficiencies in excess of 10%. Both devices show similar charge generation and recombination behaviours, supporting formation of similar BHJ active layers. We correlate the approximate to 30 meV smaller open-circuit voltage in sq-BHJ devices to more substantial non-radiative recombination by voltage loss analysis. We also determine the exciton diffusion length of benchmark polymer PBDB-T to be 10 +/- 3 nm. Our results demonstrate high-efficiency OSC devices using sequential deposition method and provide new opportunities to further improve performance of state-of-the-art OSCs.

    Download full text (pdf)
    fulltext
  • 718.
    Zhang, Jianyun
    et al.
    Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; School of Chemical Sciences, University of Chinese Academy of Sciences, China.
    Liu, Wenrui
    Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; School of Chemical Sciences, University of Chinese Academy of Sciences, China.
    Zhang, Ming
    School of Chemistry and Chemical Engineering, and Center for Advanced Electronic Materials and Devices, Shanghai Jiao Tong University, China.
    Liu, Yanfeng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhou, Guanqing
    School of Chemistry and Chemical Engineering, and Center for Advanced Electronic Materials and Devices, Shanghai Jiao Tong University, China.
    Xu, Shengjie
    Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, China.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhu, Haiming
    Department of Chemistry, Zhejiang University, China.
    Liu, Feng
    School of Chemistry and Chemical Engineering, and Center for Advanced Electronic Materials and Devices, Shanghai Jiao Tong University, China.
    Zhu, Xiaozhang
    Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; School of Chemical Sciences, University of Chinese Academy of Sciences, China.
    Revealing the Critical Role of the HOMO Alignment on Maximizing Current Extraction and Suppressing Energy Loss in Organic Solar Cells2019In: iScience, ISSN 2589-0042, Vol. 19, p. 883-893Article in journal (Refereed)
    Abstract [en]

    For state-of-the-art organic solar cells (OSCs) consisting of a large-bandgap polymer donor and a near-infrared (NIR) molecular acceptor, the control of the HOMO offset is the key to simultaneously achieve small energy loss (Eloss) and high photocurrent. However, the relationship between HOMO offsets and the efficiency for hole separation is quite elusive so far, which requires a comprehensive understanding on how small the driving force can effectively perform the charge separation while obtaining a high photovoltage to ensure high OSC performance. By designing a new family of ZITI-X NIR acceptors (X = S, C, N) with a high structural similarity and matching them with polymer donor J71 forming reduced HOMO offsets, we systematically investigated and established the relationship among the photovoltaic performance, energy loss, and hole-transfer kinetics. We achieved the highest PCEavgs of 14.05 ± 0.21% in a ternary system (J71:ZITI-C:ZITI-N) that best optimize the balance between driving force and energy loss.

    Download full text (pdf)
    fulltext
  • 719.
    Zhang, Liangdong
    et al.
    Nanjing Tech Univ, Peoples R China.
    Jiang, Tao
    Nanjing Tech Univ, Peoples R China.
    Yi, Chang
    Nanjing Tech Univ, Peoples R China.
    Wu, Jiquan
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Liu, Xiaoke
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    He, Yaron
    Nanjing Tech Univ, Peoples R China.
    Miao, Yanfeng
    Nanjing Tech Univ, Peoples R China.
    Zhang, Ya
    Nanjing Tech Univ, Peoples R China.
    Zhang, Huotian
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Xie, Xinrui
    Zhejiang Univ, Peoples R China.
    Wang, Peng
    Zhejiang Univ, Peoples R China.
    Li, Renzhi
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Huang, Wei
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China; NPU, Peoples R China.
    Wang, Jianpu
    Nanjing Tech Univ, Peoples R China.
    Bright Free Exciton Electroluminescence from Mn-Doped Two-Dimensional Layered Perovskites2019In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 10, no 11, p. 3171-3175Article in journal (Refereed)
    Abstract [en]

    Two-dimensional (2D) perovskites incorporating hydrophobic organic spacer cations show improved film stability and morphology compared to their three-dimensional (3D) counterparts. However, 2D perovskites usually exhibit low photoluminescence quantum efficiency (PLQE) owing to strong exciton-phonon interaction at room temperature, which limits their efficiency in light-emitting diodes (LEDs). Here, we demonstrate that the device performance of 2D perovskite LEDs can be significantly enhanced by doping Mn(2+)in (benzimidazolium)(2)PbI4 2D perovskite films to suppress the exciton-phonon interaction. The distorted [PbI6](4-) octahedra by Mn-doping and the rigid benzimidazolium (BIZ) ring without branched chains in the 2D perovskite structure lead to improved crystallinity and rigidity of the perovskites, resulting in suppressed phonon-exciton interaction and enhanced PLQE. On the basis of this strategy, for the first time, we report yellow electroluminescence from free excitons in 2D (n = 1) perovskites with a maximum brightness of 225 cd m(-2) and a peak EQE of 0.045%.

    Download full text (pdf)
    fulltext
  • 720.
    Zhang, Wenjun
    et al.
    Chinese Academic Science, Peoples R China .
    Wu, Yulei
    Chinese Academic Science, Peoples R China .
    Bao, Qinye
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, The Institute of Technology.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Fang, Junfeng
    Chinese Academic Science, Peoples R China .
    Morphological Control for Highly Efficient Inverted Polymer Solar Cells Via the Backbone Design of Cathode Interlayer Materials2014In: ADVANCED ENERGY MATERIALS, ISSN 1614-6832, Vol. 4, no 12, p. 1400359-Article in journal (Refereed)
    Abstract [en]

    Two alcohol-soluble organic molecules are synthesized and introduced into inverted organic solar cells as the cathode interlayer. A power conversion efficiency as high as 9.22% is obtained by using the more hydrophobic molecule FTBTF-N as the cathode interlayer. Morphological studies suggest that design of the backbone can help to enhance short-circuit current density and fill factor.

    Download full text (pdf)
    fulltext
  • 721.
    Zhang, Xin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Yuan, Lin
    Anhui Univ, Peoples R China.
    Jiang, Jianxia
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering. South China Univ Technol, Peoples R China.
    Hu, Jiwen
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Du Rietz, Anna
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Cao, Hongzhi
    Anhui Univ, Peoples R China.
    Zhang, Ruilong
    Anhui Univ, Peoples R China.
    Tian, Xiaohe
    Anhui Univ, Peoples R China.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Ma, Yuguang
    South China Univ Technol, Peoples R China.
    Zhang, Zhongping
    Anhui Univ, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Light-Up Lipid Droplets Dynamic Behaviors Using a Red-Emitting Fluorogenic Probe2020In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 92, no 5, p. 3613-3619Article in journal (Refereed)
    Abstract [en]

    Intracellular lipid metabolism occurs in lipid droplets (LDs), which is critical to the survival of cells. Imaging LDs is an intuitive way to understand their physiology in live cells. However, this is limited by the availability of specific probes that can properly visualize LDs in vivo. Here, an LDs-specific red-emitting probe is proposed to address this need, which is not merely with an ultrahigh signal-to-noise (S/N) ratio and a large Stokes shift (up to 214 nm) but also with superior resistance to photobleaching. The probe has been successfully applied to real-time tracking of intracellular LDs behaviors, including fusion, migration, and lipophagy processes. We deem that the proposed probe here offers a new possibility for deeper understanding of LDs-associated behaviors, elucidation of their roles and mechanisms in cellular metabolism, and determination of the transition between adaptive lipid storage and lipotoxicity as well.

    Download full text (pdf)
    fulltext
  • 722.
    Zhang, Y.
    et al.
    University of Cambridge, England.
    Kappers, M. J.
    University of Cambridge, England.
    Zhu, D.
    University of Cambridge, England.
    Oehler, F.
    University of Cambridge, England.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Humphreys, C. J.
    University of Cambridge, England.
    The effect of dislocations on the efficiency of InGaN/GaN solar cells2013In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 117, p. 279-284Article in journal (Refereed)
    Abstract [en]

    Two solar cells based on an InGaN/GaN p-i-n hetero-junction, but having different dislocation densities, were fabricated and characterized. The structures were grown on c-plane (0001) GaN-on-sapphire templates with different threading dislocation (TD) densities of 5 x 10(8) and 5 x 10(9) cm(-2). Structural characterization revealed the presence of V-defects in the InGaN epilayer. Since each V-defect was associated with a TD, the structural as well as the optical properties worsened with a higher TO density in the GaN/sapphire template. It was also found that additional dislocations were generated in the p-GaN layer over the V-defects in the InGaN layer. Because of its superior structural quality, the peak external quantum efficiency (EQE) of the low TO density sample was three times higher than that of the high TD density sample. (C) 2013 Elsevier B.V. All rights reserved.

  • 723.
    Zhang, Yun
    et al.
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Yao, Huifeng
    Chinese Acad Sci, Peoples R China.
    Zhang, Shaoqing
    Chinese Acad Sci, Peoples R China; Univ Sci and Technol Beijing, Peoples R China.
    Qin, Yunpeng
    Chinese Acad Sci, Peoples R China; Univ Sci and Technol Beijing, Peoples R China.
    Zhang, Jianqi
    Natl Ctr Nanosci and Technol, Peoples R China.
    Yang, Liyan
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Li, Wanning
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Wei, Zhixiang
    Natl Ctr Nanosci and Technol, Peoples R China.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Hou, Jianhui
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Fluorination vs. chlorination: a case study on high performance organic photovoltaic materials2018In: Science in China Series B: Chemistry, ISSN 1674-7291, E-ISSN 1869-1870, Vol. 61, no 10, p. 1328-1337Article in journal (Refereed)
    Abstract [en]

    Halogenation is a very efficient chemical modification method to tune the molecular energy levels, absorption spectra and molecular packing of organic semiconductors. Recently, in the field of organic solar cells (OSCs), both fluorine- and chlorinesubstituted photovoltaic materials, including donors and acceptors, demonstrated their great potentials in achieving high power conversion efficiencies (PCEs), raising a question that how to make a decision between fluorination and chlorination when designing materials. Herein, we systemically studied the impact of fluorination and chlorination on the properties of resulting donors (PBDB-T-2F and PBDB-T-2Cl) and acceptors (IT-4F and IT-4Cl). The results suggest that all the OSCs based on different donor and acceptor combinations can deliver good PCEs around 13%-14%. Chlorination is more effective than fluorination in downshifting the molecular energy levels and broadening the absorption spectra. The influence of chlorination and fluorination on the crystallinity of the resulting materials is dependent on their introduction positions. As chlorination has the advantage of easy synthesis, it is more attractive in designing low-cost photovoltaic materials and therefore may have more potential in largescale applications.

  • 724.
    Zhao, Baodan
    et al.
    Univ Cambridge, England.
    Bai, Sai
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Univ Oxford, England.
    Kim, Vincent
    Univ Cambridge, England.
    Lamboll, Robin
    Univ Cambridge, England.
    Shivanna, Ravichandran
    Univ Cambridge, England.
    Auras, Florian
    Univ Cambridge, England.
    Richter, Johannes M.
    Univ Cambridge, England.
    Yang, Le
    Univ Cambridge, England; ASTAR, Singapore.
    Dai, Linjie
    Univ Cambridge, England.
    Alsari, Mejd
    Univ Cambridge, England.
    She, Xiao-Jian
    Univ Cambridge, England.
    Liang, Lusheng
    Chinese Acad Sci, Peoples R China.
    Zhang, Jiangbin
    Univ Cambridge, England.
    Lilliu, Samuele
    Univ Sheffield, England; UAE Ctr Crystallog, U Arab Emirates.
    Gao, Peng
    Chinese Acad Sci, Peoples R China.
    Snaith, Henry J.
    Univ Oxford, England.
    Wang, Jianpu
    Nanjing Tech Univ, Peoples R China.
    Greenham, Neil C.
    Univ Cambridge, England.
    Friend, Richard H.
    Univ Cambridge, England.
    Di, Dawei
    Univ Cambridge, England.
    High-efficiency perovskite-polymer bulk heterostructure light-emitting diodes2018In: Nature Photonics, ISSN 1749-4885, E-ISSN 1749-4893, Vol. 12, no 12, p. 783-+Article in journal (Refereed)
    Abstract [en]

    Perovskite-based optoelectronic devices are gaining much attention owing to their remarkable performance and low processing cost, particularly for solar cells. However, for perovskite light-emitting diodes, non-radiative charge recombination has limited the electroluminescence efficiency. Here we demonstrate perovskite-polymer bulk heterostructure light-emitting diodes exhibiting external quantum efficiencies of up to 20.1% (at current densities of 0.1-1 mA cm(-2)). The light-emitting diode emissive layer comprises quasi-two-dimensional and three-dimensional (2D/3D) perovskites and an insulating polymer. Photogenerated excitations migrate from quasi-2D to lower-energy sites within 1 ps, followed by radiative bimolecular recombination in the 3D regions. From near-unity external photoluminescence quantum efficiencies and transient kinetics of the emissive layer with and without charge-transport contacts, we find non-radiative recombination pathways to be effectively eliminated, consistent with optical models giving near 100% internal quantum efficiencies. Although the device brightness and stability (T-50 = 46 h in air at peak external quantum efficiency) require further improvement, our results indicate the significant potential of perovskite-based photon sources.

    Download full text (pdf)
    fulltext
  • 725.
    Zhao, Wenchao
    et al.
    Chinese Academic Science, Peoples R China.
    Qian, Deping
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhang, Shaoqing
    Chinese Academic Science, Peoples R China.
    Li, Sunsun
    Chinese Academic Science, Peoples R China.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Hou, Jianhui
    Chinese Academic Science, Peoples R China.
    Fullerene-Free Polymer Solar Cells with over 11% Efficiency and Excellent Thermal Stability2016In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 28, no 23, p. 4734-4739Article in journal (Refereed)
    Abstract [en]

    A nonfullerene-based polymer solar cell (PSC) that significantly outperforms fullerene-based PSCs with respect to the power-conversion efficiency is demonstrated for the first time. An efficiency of amp;gt;11%, which is among the top values in the PSC field, and excellent thermal stability is obtained using PBDB-T and ITIC as donor and acceptor, respectively.

  • 726.
    ZHAO, Yang
    et al.
    Jilin University, Changchun, P. R. China.
    ZHANG, Feng-ling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    ZHANG, Ming
    Jilin University, Changchun, P. R. China.
    MA, Yu-guang
    Jilin University, Changchun, P. R. China.
    Characterization and properties of a new amorphous small-molecule material containing both donor and acceptor moieties for photovoltaic application2013In: Chemical Research in Chinese Universities, ISSN 1005-9040, E-ISSN 2210-3171, Vol. 29, no 6, p. 1193-1198Article in journal (Refereed)
    Abstract [en]

    A new amorphous small-molecule material, in which the electron-donating carbazole units are connected to the backbone by flexible side chains, has been synthesized and utilised in the photovoltaic(PV) field. This material exhibits the amorphous feature, higher thermal stability and good film forming ability. The influence of the heat-treatment on the morphology and the performance of PV devices were studied. Eventually, a relatively high photovoltaic conversion efficiency was achieved. At the same time, the PV device displayed an ideal open-circuit voltage(over 1 V) which is very close to the upper limit of its theoretical value.

  • 727.
    Zhen, Hongyu
    et al.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology. State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027, China.
    Hou, Qiong
    S China Normal University, Peoples R China S China University of Technology, Peoples R China .
    Li, Kan
    Zhejiang University, Peoples R China .
    Ma, Zaifei
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Solution-processed bulk-heterojunction organic solar cells employing Ir complexes as electron donors2014In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2, no 31, p. 12390-12396Article in journal (Refereed)
    Abstract [en]

    To explore enhancing photocurrent in organic solar cells (OSCs) via harvesting triplet excitons, two novel bicycloiridium complexes (R-1 and R-2) are designed and synthesized. Conventional bulk-heterojunction triplet OSCs are solution processed using R-1 or R-2 as sole electron donors and phenyl-C-71-butyric acid methyl ester (PC71BM) as the electron acceptor. A decent short circuit current (J(sc)) of 6.5 mA cm(-2) is achieved though the overlap between the absorption spectrum (with similar to 550 nm absorption onset) of R-2 and the solar flux is relatively small. With an open circuit voltage of 0.74 V and a fill factor of 0.42, an encouraging power conversion efficiency of 2.0% is achieved in the OSCs based on R-2 and PC71BM without any processing additives and post-treatments. Our preliminary result demonstrates the possibility of utilizing Ir complexes as sole electron donors in OSCs, which extends available soluble small molecules for OSCs.

  • 728.
    Zhen, Hongyu
    et al.
    Zhejiang Univ, Peoples R China.
    Li, Kan
    Zhejiang University, Peoples R China .
    Huang, Zhuoyin
    Zhejiang University, Peoples R China .
    Tang, Zheng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Wu, Rengmao
    Zhejiang University, Peoples R China .
    Li, Guolong
    Zhejiang University, Peoples R China .
    Liu, Xu
    Zhejiang University, Peoples R China .
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Inverted indium-tin-oxide-free cone-shaped polymer solar cells for light trapping2012In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 100, no 21, p. 213901-Article in journal (Refereed)
    Abstract [en]

    Based on the flexibility of polymer film, cone-shaped polymer solar cells (PSCs) are fabricated and studied. Effective light trapping is achieved due to multi-absorption in all 360 degrees directions. Monte Carlo ray tracing is used to simulate the absorption of cone-shaped PSCs with two variables: wavelength and half cone angle. With an inverted indium-tin-oxide-free device structure, a 43% enhanced light utilization without loss of material utilization is realized in the cone-shaped PSCs with a half cone angle of 45 degrees, compared with the planar PSCs.

    Download full text (pdf)
    fulltext
  • 729.
    Zheng, Kaibo
    et al.
    Lund University, Sweden .
    Zidek, Karel
    Lund University, Sweden .
    Abdellah, Mohamed
    Lund University, Sweden .
    Torbjornsson, Magne
    Lund University, Sweden .
    Chabera, Pavel
    Lund University, Sweden .
    Shao, Shuyan
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. 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.
    Pullerits, Tonu
    Lund University, Sweden .
    Fast Monolayer Adsorption and Slow Energy Transfer in CdSe Quantum Dot Sensitized ZnO Nanowires2013In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 117, no 29, p. 5919-5925Article in journal (Refereed)
    Abstract [en]

    A method for CdSe quantum dot (QD) sensitization of ZnO nanowires (NW) with fast adsorption rate is applied. Photoinduced excited state dynamics of the quantum dots in the case of more than monolayer coverage of the nanowires is studied. Transient absorption kinetics reveals an excitation depopulation process of indirectly attached quantum dots with a lifetime of similar to 4 ns. Photoluminescence and incident photon-to-electron conversion efficiency show that this process consists of both radiative e-h recombination and nonradiative excitation-to-charge conversion. We argue that the latter occurs via interdot energy transfer from the indirectly attached QDs to the dots with direct contact to the nanowires. From the latter, fast electron injection into ZnO occurs. The energy transfer time constant is found to be around 5 ns.

  • 730.
    Zheng, Wenhao
    et al.
    Jinan University, Peoples R China.
    Lin, Yuanbao
    Jinan University, Peoples R China.
    Zhang, Yangdong
    Jinan University, Peoples R China.
    Yang, Junyu
    Jinan University, Peoples R China.
    Peng, Zuosheng
    Jinan University, Peoples R China.
    Liu, Alei
    Jinan University, Peoples R China.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Jinan University, Peoples R China.
    Hou, Lintao
    Jinan University, Peoples R China.
    Dual Function of UV/Ozone Plasma-Treated Polymer in Polymer/Metal Hybrid Electrodes and Semitransparent Polymer Solar Cells2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 51, p. 44656-44666Article in journal (Refereed)
    Abstract [en]

    In this work, high-performance inverted indium tin oxide (ITO)-free semitransparent polymer solar cells are comprehensively investigated using a novel polymer/metal hybrid transparent electrode. The electrical and optical characteristics of hybrid electrodes are significantly enhanced by introducing UV/ozone plasma treatment on the polymer poly[(9,9-bis(3-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN), which is functioned as both a seed layer for ultrathin Ag metal electrode and an optical spacer for transparent devices. The optimized sheet resistance of PFN/Ag (12 nm) hybrid electrode is only half of the commercial ITO (9.4 vs 20.0 Omega sq(-1)) and the high wavelength-dependent reflectance of hybrid electrode helps to increase the ITO-free device short-circuit current density. Furthermore, the interface property between PFN and ultrathin Ag is analyzed in detail and the optical field distribution is calculated for comparison. A high power conversion efficiency of 5.02%, which is increased by 35% compared to that of the ITO-based device, is achieved in the ITO-free semitransparent device in conjunction with an excellent average visible transmittance above 28% that is higher than the benchmark of 25% for power-generating window, indicating its great potential in building integrated photovoltaic systems in the future. Furthermore, the strategy is successfully developed for other polymer systems, suggesting the universal applicability for plastic electronics.

    Download full text (pdf)
    fulltext
  • 731.
    Zheng, Xiaopeng
    et al.
    KAUST, Saudi Arabia.
    Hou, Yi
    Univ Toronto, Canada.
    Bao, Chunxiong
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Yin, Jun
    KAUST, Saudi Arabia.
    Yuan, Fanglong
    Univ Toronto, Canada.
    Huang, Ziru
    University of Toronto, Toronto, Ontario, Canada.
    Song, Kepeng
    KAUST, Saudi Arabia.
    Liu, Jiakai
    KAUST, Saudi Arabia.
    Troughton, Joel
    KAUST, Saudi Arabia.
    Gasparini, Nicola
    KAUST, Saudi Arabia.
    Zhou, Chun
    Univ Toronto, Canada.
    Lin, Yuanbao
    KAUST, Saudi Arabia.
    Xue, Ding-Jiang
    Univ Toronto, Canada.
    Chen, Bin
    Univ Toronto, Canada.
    Johnston, Andrew K.
    Univ Toronto, Canada.
    Wei, Nini
    KAUST, Saudi Arabia.
    Hedhili, Mohamed Nejib
    KAUST, Saudi Arabia.
    Wei, Mingyang
    Univ Toronto, Canada.
    Alsalloum, Abdullah Y.
    KAUST, Saudi Arabia.
    Maity, Partha
    KAUST, Saudi Arabia.
    Turedi, Bekir
    KAUST, Saudi Arabia.
    Yang, Chen
    KAUST, Saudi Arabia.
    Baran, Derya
    KAUST, Saudi Arabia.
    Anthopoulos, Thomas D.
    KAUST, Saudi Arabia.
    Han, Yu
    KAUST, Saudi Arabia.
    Lu, Zheng-Hong
    Univ Toronto, Canada.
    Mohammed, Omar F.
    KAUST, Saudi Arabia.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Sargent, Edward H.
    Univ Toronto, Canada.
    Bakr, Osman M.
    KAUST, Saudi Arabia.
    Managing grains and interfaces via ligand anchoring enables 22.3%-efficiency inverted perovskite solar cells2020In: NATURE ENERGY, ISSN 2058-7546, Vol. 5, p. 131-140Article in journal (Refereed)
    Abstract [en]

    Inverted perovskite solar cells have attracted increasing attention because they have achieved long operating lifetimes. However, they have exhibited significantly inferior power conversion efficiencies compared to regular perovskite solar cells. Here we reduce this efficiency gap using a trace amount of surface-anchoring alkylamine ligands (AALs) with different chain lengths as grain and interface modifiers. We show that long-chain AALs added to the precursor solution suppress nonradiative carrier recombination and improve the optoelectronic properties of mixed-cation mixed-halide perovskite films. The resulting AAL surface-modified films exhibit a prominent (100) orientation and lower trap-state density as well as enhanced carrier mobilities and diffusion lengths. These translate into a certified stabilized power conversion efficiency of 22.3% (23.0% power conversion efficiency for lab-measured champion devices). The devices operate for over 1,000 h at the maximum power point under simulated AM1.5 illumination, without loss of efficiency. While perovskite solar cells with an inverted architecture hold great promise for operation stability, their power conversion efficiency lags behind that of conventional cells. Here, Zheng et al. achieve a certified 22.34% efficiency, exploiting alkylamine ligands as grain and interface modifiers.

  • 732.
    Zhou, Ke
    et al.
    Xi An Jiao Tong Univ, Peoples R China.
    Liu, Yanfeng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Alotaibi, Awwad
    Washington State Univ, WA 99164 USA.
    Yuan, Jian
    Xi An Jiao Tong Univ, Peoples R China.
    Jiang, Chuanxiu
    Natl Ctr Nanosci and Technol, Peoples R China.
    Xin, Jingming
    Xi An Jiao Tong Univ, Peoples R China.
    Liu, Xinfeng
    Natl Ctr Nanosci and Technol, Peoples R China.
    Collins, Brian A.
    Washington State Univ, WA 99164 USA.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Ma, Wei
    Xi An Jiao Tong Univ, Peoples R China.
    Molecular and Energetic Order Dominate the Photocurrent Generation Process in Organic Solar Cells with Small Energetic Offsets2020In: ACS ENERGY LETTERS, ISSN 2380-8195, Vol. 5, no 2, p. 589-596Article in journal (Refereed)
    Abstract [en]

    Minimizing the energetic offset between the donor (D) and acceptor (A) in organic solar cells (OSCs) is pivotal for reducing the charge-transfer (CT) loss and improving the open-circuit voltage (V-oc). This nevertheless leads to a topic of debate regarding the driving force for the charge separation in OSCs with small energetic offsets. The molecular packing geometries in the active layer determine the energetic levels and trap density, but their relationship with the driving force is seldom considered. Limited by the complicated demixing morphology and inaccurate measurements of energy levels in the prototypical bulk-heterojunction (BHJ) devices, we thereby demonstrate a concise and robust planar-heterojunction model of PM7/N2200 to investigate the origin of driving force for charge generation. It is surprising to note that the device with smaller energy offset shows higher efficiency. Further analysis reveals that a bilayer device with short-range packing PM7 exhibits smaller energetic offsets along with fewer morphological defects and traps compared to its long-range packing counterparts. This molecular packing characteristic diminishes the energetic disorder at the D/A interfaces and inhibits the trap-assisted charge recombination, contributing to the increased short-circuit current (J(SC)) and V-OC. Our results suggest that the energetic offset actually has limited influence on charge separation, while the synergetic control of molecular and energetic order is vital to the photocurrent generation and energy loss reduction in OSCs.

  • 733.
    Zhou, Ke
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Xi An Jiao Tong Univ, Peoples R China.
    Wu, Yang
    Xi An Jiao Tong Univ, Peoples R China.
    Liu, Yanfeng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhou, Xiaobo
    Xi An Jiao Tong Univ, Peoples R China.
    Zhang, Lin
    Xi An Jiao Tong Univ, Peoples R China.
    Ma, Wei
    Xi An Jiao Tong Univ, Peoples R China.
    Molecular Orientation of Polymer Acceptor Dominates Open-Circuit Voltage Losses in All-Polymer Solar Cells2019In: ACS ENERGY LETTERS, ISSN 2380-8195, Vol. 4, no 5, p. 1057-1064Article in journal (Refereed)
    Abstract [en]

    Low open-circuit voltage (V-oc) induced by energy loss in organic solar cells is considered to be one of the most influencing factors limiting device performance, in which morphology of the active layer plays a crucial role in determining energy loss. By employing a bilayer structure of the P3HT:N2200 all-polymer system, we have identified the isolated impact of a molecular packing structure on device V-oc with analysis of energy loss processes. Thermal annealing and various solvents were used to control molecular orientation in P3HT:N2200 bilayer devices, in which different V-oc spanning from 0.45 to 0.54 V could be obtained. It was found that energy of charge-transfer state (E-ct) differed in these bilayer devices. Besides, increased charge recombination could be observed in bilayer devices when N2200 layers exhibited face-on orientation, which caused an additional energy loss and decreased V-oc. Our results suggest that rational control of polymer molecular orientation is essential to reduce the energy loss and ultimately achieve high V-oc in all-polymer solar cells.

  • 734.
    Zhou, Ke
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Xi An Jiao Tong Univ, Peoples R China.
    Zhou, Xiaobo
    Xi An Jiao Tong Univ, Peoples R China.
    Xu, Xiaofeng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Musumeci, Chiara
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Wang, Chuan Fei
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, Faculty of Science & Engineering.
    Xu, Weidong
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Nanjing Tech Univ NanjingTech, Peoples R China.
    Meng, Xiangyi
    Xi An Jiao Tong Univ, Peoples R China.
    Ma, Wei
    Xi An Jiao Tong Univ, Peoples R China.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    pi-pi Stacking Distance and Phase Separation Controlled Efficiency in Stable All-Polymer Solar Cells2019In: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, POLYMERS, Vol. 11, no 10, article id 1665Article in journal (Refereed)
    Abstract [en]

    The morphology of the active layer plays a crucial role in determining device performance and stability for organic solar cells. All-polymer solar cells (All-PSCs), showing robust and stable morphologies, have been proven to give better thermal stability than their fullerene counterparts. However, outstanding thermal stability is not always the case for polymer blends, and the limiting factors responsible for the poor thermal stability in some All-PSCs, and how to obtain higher efficiency without losing stability, still remain unclear. By studying the morphology of poly [2,3-bis (3-octyloxyphenyl) quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl](TQ1)/poly[4,8-bis[5-(2-ethylhexyl)-2-thienyl]benzo[1,2-b:4,5-b ]dithiophene-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl]] (PCE10)/PNDI-T10 blend systems, we found that the rearranged molecular packing structure and phase separation were mainly responsible for the poor thermal stability in devices containing PCE10. The TQ1/PNDI-T10 devices exhibited an improved PCE with a decreased pi-pi stacking distance after thermal annealing; PCE10/PNDI-T10 devices showed a better pristine PCE, however, thermal annealing induced the increased pi-pi stacking distance and thus inferior hole conductivity, leading to a decreased PCE. Thus, a maximum PCE could be achieved in a TQ1/PCE10/PNDI-T10 (1/1/1) ternary system after thermal annealing resulting from their favorable molecular interaction and the trade-off of molecular packing structure variations between TQ1 and PCE10. This indicates that a route to efficient and thermal stable All-PSCs can be achieved in a ternary blend by using material with excellent pristine efficiency, combined with another material showing improved efficiency under thermal annealing.

    Download full text (pdf)
    fulltext
  • 735.
    Zhou, Ruimin
    et al.
    Natl Ctr Nanosci and Technol, Peoples R China; Univ Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China; Univ Copenhagen, Denmark; Univ Copenhagen, Denmark.
    Jiang, Zhaoyan
    Natl Ctr Nanosci and Technol, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Yang, Chen
    Natl Ctr Nanosci and Technol, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Yu, Jianwei
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Feng, Jirui
    Xi An Jiao Tong Univ, Peoples R China.
    Adil, Muhammad Abdullah
    Natl Ctr Nanosci and Technol, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Deng, Dan
    Natl Ctr Nanosci and Technol, Peoples R China.
    Zou, Wenjun
    Natl Ctr Nanosci and Technol, Peoples R China.
    Zhang, Jianqi
    Natl Ctr Nanosci and Technol, Peoples R China.
    Lu, Kun
    Natl Ctr Nanosci and Technol, Peoples R China.
    Ma, Wei
    Xi An Jiao Tong Univ, Peoples R China.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Wei, Zhixiang
    Natl Ctr Nanosci and Technol, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    All-small-molecule organic solar cells with over 14% efficiency by optimizing hierarchical morphologies2019In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 10, article id 5393Article in journal (Refereed)
    Abstract [en]

    The high efficiency all-small-molecule organic solar cells (OSCs) normally require optimized morphology in their bulk heterojunction active layers. Herein, a small-molecule donor is designed and synthesized, and single-crystal structural analyses reveal its explicit molecular planarity and compact intermolecular packing. A promising narrow bandgap small-molecule with absorption edge of more than 930 nm along with our home-designed small molecule is selected as electron acceptors. To the best of our knowledge, the binary all-small-molecule OSCs achieve the highest efficiency of 14.34% by optimizing their hierarchical morphologies, in which the donor or acceptor rich domains with size up to ca. 70 nm, and the donor crystals of tens of nanometers, together with the donor-acceptor blending, are proved coexisting in the hierarchical large domain. All-small-molecule photovoltaic system shows its promising for high performance OSCs, and our study is likely to lead to insights in relations between bulk heterojunction structure and photovoltaic performance.

    Download full text (pdf)
    fulltext
  • 736.
    Zhou, Yang
    et al.
    Chinese University of Hong Kong, Peoples R China.
    Wang, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Cao, Yu
    Nanjing Technical University, Peoples R China.
    Wang, Jian-Pu
    Nanjing Technical University, Peoples R China.
    Fang, Hong-Hua
    Zernike Institute Adv Mat, Netherlands.
    Antonietta Loi, Maria
    Zernike Institute Adv Mat, Netherlands.
    Zhao, Ni
    Chinese University of Hong Kong, Peoples R China.
    Wong, Ching-Ping
    Chinese University of Hong Kong, Peoples R China.
    Benzylamine-Treated Wide-Bandgap Perovskite with High Thermal-Photostability and Photovoltaic Performance2017In: ADVANCED ENERGY MATERIALS, ISSN 1614-6832, Vol. 7, no 22, article id 1701048Article in journal (Refereed)
    Abstract [en]

    Mixed iodide-bromide organolead perovskites with a bandgap of 1.70-1.80 eV have great potential to boost the efficiency of current silicon solar cells by forming a perovskite-silicon tandem structure. Yet, the stability of the perovskites under various application conditions, and in particular combined light and heat stress, is not well studied. Here, FA(0.15)Cs(0.85)Pb(I0.73Br0.27)(3), with an optical bandgap of approximate to 1.72 eV, is used as a model system to investigate the thermal-photostability of wide-bandgap mixed halide perovskites. It is found that the concerted effect of heat and light can induce both phase segregation and decomposition in a pristine perovskite film. On the other hand, through a postdeposition film treatment with benzylamine (BA) molecules, the highly defective regions (e.g., film surface and grain boundaries) of the film can be well passivated, thus preventing the progression of decomposition or phase segregation in the film. Besides the stability improvement, the BA-modified perovskite solar cells also exhibit excellent photovoltaic performance, with the champion device reaching a power conversion efficiency of 18.1%, a stabilized power output efficiency of 17.1% and an open-circuit voltage (V-oc) of 1.24 V.

  • 737.
    Zhou, Yi
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Antenehe Gedefaw, Desta
    University of Addis Ababa.
    Hellstrom, Stefan
    Chalmers.
    Kratschmer, Ilse
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Mammo, Wendimagegn
    University of Addis Ababa.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Andersson, Mats R
    Chalmers.
    Black Polymers in Bulk-Heterojunction Solar Cells2010In: IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, ISSN 1077-260X, Vol. 16, no 6, p. 1565-1572Article in journal (Refereed)
    Abstract [en]

    The active materials in polymer solar cells have a decisive role on the performance of the cells. Polymers with extended absorption, i.e., black polymers with absorption covering the whole visible region are desired in order to capture the important parts of the solar irradiation. Different ways of achieving black active materials are discussed and two new alternating polyfluorene (APFO) copolymers with broad absorption, APFO-Black 1 and APFO-Black 2, using two different design strategies are described. The UV-Vis absorption spectra of the polymers extend to approximately 850 nm, and the polymers were used as donors and [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM)[60] or PCBM[70] as acceptors in solar cell devices in various mixing ratios. The best combinations yielded an overall power conversion efficiency of 1.2% for APFO-Black 1 and 1.5% for APFO-Black 2.

  • 738.
    Zhou, Yi
    et al.
    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.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Du, Chunxia
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Ni, Wei-Xin
    Linköping University, Department of Physics, Chemistry and Biology, Surface and Semiconductor Physics. Linköping University, The Institute of Technology.
    Andersson, Mats R
    Chalmers, Dept Chem & Biol Engn.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Observation of a Charge Transfer State in Low-Bandgap Polymer/Fullerene Blend Systems by Photoluminescence and Electroluminescence Studies2009In: ADVANCED FUNCTIONAL MATERIALS, ISSN 1616-301X, Vol. 19, no 20, p. 3293-3299Article in journal (Refereed)
    Abstract [en]

    The presence of charge transfer states generated by the interaction between the fullerene acceptor PCBM and two alternating copolymers of fluorene with donor-acceptor-donor comonomers are reported; the generation leads to modifications in the polymer bandgap and electronic structure. In one of polymer/fullerene blends, the driving; force for photocurrent generation, i.e., the gap between the lowest unoccupied molecular orbitals of the donor and acceptor, is only 0.1 eV, but photocurrent is generated. It is shown that the presence of a charge transfer state is more important than the driving force. The charge transfer states are visible through new emission peaks in the photoluminescence spectra and through electroluminescence at a forward bias. The photoluminescence can be quenched under reverse bias, and can be directly correlated to the mechanism of photocurrent generation. The excited charge transfer state is easily dissociated into free charge carriers, and is an important intermediate state through which free charge carriers are generated.

  • 739.
    Zhou, Yinhua
    et al.
    Jilin University.
    Li, Fenghong
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, The Institute of Technology.
    Barrau, Sophie
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Tian, Wenjing
    Jilin University.
    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.
    Inverted and transparent polymer solar cells prepared with vacuum-free processing2009In: SOLAR ENERGY MATERIALS AND SOLAR CELLS, ISSN 0927-0248, Vol. 93, no 4, p. 497-500Article in journal (Refereed)
    Abstract [en]

    Inverted transparent polymer solar cells were fabricated by sequentially depositing several organic layers from fluids, on ITO/glass substrates. ITO was used as a cathode to collect electrons. The photovoltage of these diodes can be increased by up to 400 mV by inserting a buffer layer of polyethylene oxide between ITO and the active layers, which results in 4-fold enhancement of power conversion efficiency under the illumination of 100 mW/cm(2) simulated AM1.5 solar light. The enhancement of V., is consistent with the work function change between ITO and ITO/PEO measured by photoelectron spectroscopy. Solar cell production without vacuum processing may lower production costs.

  • 740.
    Zhou, Yinhua
    et al.
    State Key Lab for Supramolecular Structure and Materials Jilin University.
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Tvingstedt, Kristofer
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Barrau, Sophie
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Li, Fenghong
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Tian, Wenjing
    State Key Lab for Supramolecular Structure and Materials Jilin University.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Investigation on Polymer Anode Design for Flexible Polymer Solar Cells2008In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 92Article in journal (Refereed)
    Abstract [en]

       

  • 741.
    Zhou, Yinhua
    et al.
    State Key Lab for Supramolecular Structure and Materials Jilin University.
    Zhang, Fengling
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Tvingstedt, Kristofer
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Tian, Wenjing
    State Key Lab for Supramolecular Structure and Materials Jilin University.
    Inganäs, Olle
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics .
    Multifolded Polymer Solar Cells on Flexible Substrates2008In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 93, no 033302Article in journal (Refereed)
  • 742.
    Zhou, Zichun
    et al.
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Liu, Wenrui
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Zhou, Guanqing
    Shanghai Jiao Tong Univ, Peoples R China.
    Zhang, Ming
    Shanghai Jiao Tong Univ, Peoples R China.
    Qian, Deping
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhang, Jianyun
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Chen, Shanshan
    Chongqing Univ, Peoples R China; Ulsan Natl Inst Sci and Technol, South Korea.
    Xu, Shengjie
    Chinese Acad Sci, Peoples R China.
    Yang, Changduk
    Ulsan Natl Inst Sci and Technol, South Korea.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhu, Haiming
    Zhejiang Univ, Peoples R China.
    Liu, Feng
    Shanghai Jiao Tong Univ, Peoples R China.
    Zhu, Xiaozhang
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Subtle Molecular Tailoring Induces Significant Morphology Optimization Enabling over 16% Efficiency Organic Solar Cells with Efficient Charge Generation2020In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, article id 1906324Article in journal (Refereed)
    Abstract [en]

    Manipulating charge generation in a broad spectral region has proved to be crucial for nonfullerene-electron-acceptor-based organic solar cells (OSCs). 16.64% high efficiency binary OSCs are achieved through the use of a novel electron acceptor AQx-2 with quinoxaline-containing fused core and PBDB-TF as donor. The significant increase in photovoltaic performance of AQx-2 based devices is obtained merely by a subtle tailoring in molecular structure of its analogue AQx-1. Combining the detailed morphology and transient absorption spectroscopy analyses, a good structure-morphology-property relationship is established. The stronger pi-pi interaction results in efficient electron hopping and balanced electron and hole mobilities attributed to good charge transport. Moreover, the reduced phase separation morphology of AQx-2-based bulk heterojunction blend boosts hole transfer and suppresses geminate recombination. Such success in molecule design and precise morphology optimization may lead to next-generation high-performance OSCs.

  • 743.
    Zhou, Zichun
    et al.
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Xu, Shengjie
    Chinese Acad Sci, Peoples R China.
    Song, Jingnan
    Shanghai Jiao Tong Univ, Peoples R China.
    Jin, Yingzhi
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Yue, Qihui
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Qian, Yuhao
    Shanghai Jiao Tong Univ, Peoples R China.
    Liu, Feng
    Shanghai Jiao Tong Univ, Peoples R China.
    Zhang, Fengling
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Zhu, Xiaozhang
    Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    High-efficiency small-molecule ternary solar cells with a hierarchical morphology enabled by synergizing fullerene and non-fullerene acceptors2018In: NATURE ENERGY, ISSN 2058-7546, Vol. 3, no 11, p. 952-959Article in journal (Refereed)
    Abstract [en]

    Using combinatory photoactive blends is a promising approach to achieve high power conversion efficiency in ternary organic photovoltaics. However, the fundamental challenge of how to manipulate the morphology of multiple components and correlate structure details via device performance has not been well addressed. Achieving an ideal morphology that simultaneously enhances charge generation and transport and reduces voltage loss is an imperative avenue to improve device efficiency. Here, we achieve a high power conversion efficiency of 13.20 +/- 0.25% for ternary solar cells by using a combination of small molecules with both fullerene and non-fullerene acceptors, which form a hierarchical morphology consisting of a PCBM transporting highway and an intricate non-fullerene phase-separated pathway network. Carrier generation and transport find an optimized balance, and voltage loss is simultaneously reduced. Such a morphology fully utilizes the individual advantages of both fullerene and non-fullerene acceptors, demonstrating their indispensability in organic photovoltaics.

  • 744.
    Zhuang, Wenliu
    et al.
    Chalmers, Sweden .
    Zhen, Hongyu
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Kroon, Renee
    Chalmers, Sweden .
    Tang, Zheng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Hellstrom, Stefan
    Chalmers, Sweden .
    Hou, Lintao
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Wang, Ergang
    Chalmers, Sweden .
    Gedefaw, Desta
    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.
    Andersson, Mats R.
    Chalmers, Sweden .
    Molecular orbital energy level modulation through incorporation of selenium and fluorine into conjugated polymers for organic photovoltaic cells2013In: JOURNAL OF MATERIALS CHEMISTRY A, ISSN 2050-7488, Vol. 1, no 43, p. 13422-13425Article in journal (Refereed)
    Abstract [en]

    We demonstrated an effective chemical approach to modulate the energy levels of conjugated polymers by synergistically combining fluorine substitution and thiophene-selenophene exchange. Such modifications from TQ1 resulted in a significantly enhanced open-circuit voltage up to 1.0 V while retaining high photovoltaic performance.

  • 745.
    Zou, Wei
    et al.
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Li, Renzhi
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Zhang, Shuting
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Liu, Yunlong
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China; Liaocheng Univ, Peoples R China.
    Wang, Nana
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Cao, Yu
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Miao, Yanfeng
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Xu, Mengmeng
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Guo, Qiang
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Di, Dawei
    Univ Cambridge, England.
    Zhang, Li
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Yi, Chang
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Friend, Richard H.
    Univ Cambridge, England.
    Wang, Jianpu
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China.
    Huang, Wei
    Nanjing Tech Univ, Peoples R China; Nanjing Tech Univ, Peoples R China; Nanjing Univ Posts and Telecommun, Peoples R China; Nanjing Univ Posts and Telecommun, Peoples R China; Northwestern Polytech Univ, Peoples R China.
    Minimising efficiency roll-off in high-brightness perovskite light-emitting diodes2018In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 9, article id 608Article in journal (Refereed)
    Abstract [en]

    Efficiency roll-off is a major issue for most types of light-emitting diodes (LEDs), and its origins remain controversial. Here we present investigations of the efficiency roll-off in perovskite LEDs based on two-dimensional layered perovskites. By simultaneously measuring electroluminescence and photoluminescence on a working device, supported by transient photoluminescence decay measurements, we conclude that the efficiency roll-off in perovskite LEDs is mainly due to luminescence quenching which is likely caused by non-radiative Auger recombination. This detrimental effect can be suppressed by increasing the width of quantum wells, which can be easily realized in the layered perovskites by tuning the ratio of large and small organic cations in the precursor solution. This approach leads to the realization of a perovskite LED with a record external quantum efficiency of 12.7%, and the efficiency remains to be high, at approximately 10%, under a high current density of 500 mA cm(-2).

    Download full text (pdf)
    fulltext
  • 746.
    Zou, Yatao
    et al.
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Ban, Muyang
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Yang, Yingguo
    Chinese Acad Sci, Peoples R China.
    Bai, Sai
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Wu, Chen
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Han, Yujie
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Wu, Tian
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Tan, Yeshu
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Huang, Qi
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Gao, Xingyu
    Chinese Acad Sci, Peoples R China.
    Song, Tao
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Zhang, Qiao
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Sun, Baoquan
    Soochow Univ, Peoples R China; Soochow Univ, Peoples R China.
    Boosting Perovskite Light-Emitting Diode Performance via Tailoring Interfacial Contact2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 28, p. 24320-24326Article in journal (Refereed)
    Abstract [en]

    Solution-processed perovskite light-emitting diodes (LEDs) have attracted wide attention in the past several years. However, the overall efficiency and stability of perovskite-based LEDs remain inferior to those of organic or quantum dot LEDs. Nonradiative charge recombination and the unbalanced charge injection are two critical factors that limit the device efficiency and operational stability of perovskite LEDs. Here, we develop a strategy to modify the interface between the hole transport layer and the perovskite emissive layer with an amphiphilic conjugated polymer of poly[(9,9-bis(3-(N,N-dimethylamino)propy1)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN). We show evidences that PFN improves the quality of the perovskite film, which effectively suppresses nonradiative recombination. By further improving the charge injection balance rate, a green perovskite LED with a champion current efficiency of 45.2 cd/A, corresponding to an external quantum efficiency of 14.4%, is achieved. In addition, the device based on the PFN layer exhibits improved operational lifetime. Our work paves a facile way for the development of efficient and stable perovskite LEDs.

  • 747.
    Zou, Yatao
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering. Soochow Univ, Peoples R China.
    Xu, Hao
    Soochow Univ, Peoples R China.
    Li, Siying
    Soochow Univ, Peoples R China.
    Song, Tao
    Soochow Univ, Peoples R China.
    Kuai, Liang
    Soochow Univ, Peoples R China.
    Bai, Sai
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Gao, Feng
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Sun, Baoquan
    Soochow Univ, Peoples R China.
    Spectral-Stable Blue Emission from Moisture-Treated Low-Dimensional Lead Bromide-Based Perovskite Films2019In: ACS Photonics, E-ISSN 2330-4022, Vol. 6, no 7, p. 1728-1735Article in journal (Refereed)
    Abstract [en]

    Highly efficient light-emitting diodes (LEDs) based on metal halide perovskites with green, red, and near-infrared electro-luminescence have been widely demonstrated. However, the development of their blue counterparts is still hampered due to the difficult deposition of efficient and spectral-stable blue-emitting active layers. Here, we report a facile and general approach that uses a moisture treatment in combination with the precursor stoichiometry engineering for the fabrication of efficient and color stable blue-emitting perovskite films. We find that, with a short-term moisture exposure, light emission from Ruddlesden Popper lead bromide-based perovskite films exhibit a continuous blue-shift from 512 to 475 nm through incorporating excess CsBr in the precursors. In addition, we observe that the formed Cs4PbBr6 phase under CsBr-rich condition is favorable to stabilize the blue emission of the resulting films. The corresponding blue-emitting perovskite films exhibit a photoluminescence quantum efficiency of over 20%, delivering sky-blue perovskite LEDs with no change in the light emission even under high voltage. Our strategy provides an alternative way for realizing efficient and spectrally stable active layers for the further development of blue-emitting perovskite LEDs.

  • 748.
    Zuo, Guangzheng
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering.
    Abdalla, Hassan
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering.
    Kemerink, Martijn
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Conjugated Polymer Blends for Organic Thermoelectrics2019In: ADVANCED ELECTRONIC MATERIALS, ISSN 2199-160X, Vol. 5, no 11, article id 1800821Article in journal (Refereed)
    Abstract [en]

    A major attraction of organic conjugated semiconductors is that materials with new, emergent functionality can be designed and made by simple blending, as is extensively used in, e.g., bulk heterojunction organic solar cells. Herein doped blends based on organic semiconductors (OSCs) for thermoelectric applications are critically reviewed. Several experimental strategies to improve thermoelectric performance, measured in terms of power factor (PF) or figure-of-merit ZT, have been demonstrated in recent literature. Specifically, density-of-states design in blends of two OSCs can be used to obtain electronic Seebeck coefficients up to approximate to 2000 mu V K-1. Alternatively, blending with (high-dielectric constant) insulating polymers can improve doping efficiency and thereby conductivity, as well as induce more favorable morphologies that improve conductivity while hardly affecting thermopower. In the PEDOT:polystyrene-sulfonate (PEDOT:PSS) blend system, processing schemes to either improve conductivity via morphology or via (partial) removal of the electronically isolating PSS, or both, have been demonstrated. Although a range of experiments have at least quasi-quantitatively been explained by analytical or numerical models, a comprehensive model for organic thermoelectrics is lacking so far.

    Download full text (pdf)
    fulltext
  • 749.
    Åsberg, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Hydrogels of conjugated polyelectrolytes for biosensor and biochip applications2005Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis describes the use of conjugated polyelectrolytes (CPEs) in biosensor devices. The method is based on non-covalent assembly of the biomolecule of interest and the CPE functioning as the reporter, in one case as a transducer, of biomolecular events. Devices of these assemblies on solid supports that can operate in liquid solutions have been the focus. Polythiophenes, both semiconducting and conducting, is the class of materials that has been used in this work. The semiconducting polythiophenes have ionic side chains which makes them water soluble. This ionic side chain is capable of both forming electrostatic and hydrogen bonds, and when paired with the hydrophobic backbone of the polymer a great number of interactions with biomolecules are possible. The highly conducting polythiophene derivative PEDOT -PSS, (PEDOT) doped with ionic and water soluble PSS polyelectrolyte, was used as the conducting material in 3D-electrode. Both the semiconducting and conducting polymers described above forms hydrogels on solid supports if crosslinked with the appropriate ion, biomolecule or polymer. Evaluation of the CPEs, both with and without biomolecules, was performed in liquid, solid and hydrogel state using a number of techniques. This was done to understand how the CPEs behave when exposed to different buffer systems and various biomolecules.

    Hydrogels of conjugated polyelectrolytes combined with biomolecules are attractive as biosensors. The advantage with the hydrogel format is the high water content, the porous structure and the large capacity of binding molecules. High water content is important to preserve the biomolecules by providing the correct buffered environment. In this thesis we demonstrated a hydrogel of the highly conducting PEDOT -PSS polymer that was crosslinked on a solid support together with horseradish peroxidase (HRP) enzyme, forming an enzyme-enhanced electrode. Further studies of hydrogels were done using in situ quartz crystal microbalance with dissipation (QCM-D). POWT is a CPE withproperties well suited for biochip applications and readily forms hydrogels when exposed to water-based buffer solutions or biomolecule solutions. Detection ofcomplementary DNA and rejection of non-complementary DNA in a POWT hydrogel was demonstrated. The interaction between POWT and DNAoligonucleotides was also evaluated using fluorescence resonance energy transfer (FRET) in solution. Labeled DNA oligonucleotides with energy accepting or donating fluorophores allowed us to determine distance and binding stoichiometry in the non-covalent POWT-DNA complex.

    Patterning and anchoring of biomolecules and non-covalent assembled CPE-biomolecule complexes to a chip surface was studied; in the adsorbed state these complexes are hydrogels. Our novel method is based on the modification of the surface energy of a hydrophilic substrate surface using hydrophobic poly(dimethylsiloxane) (PDMS) elastomer stamp containing a relief pattern. Different conformations in biomolecules could be detected using fluorescence microscopy, where the CPEs acts as reporters and the PDMS modified substrates as discriminator. Also, excellent enzyme activity in patterned CPE/Horseradish peroxidase (HRP) enzyme was shown.

    Distances between the individual molecules in solid state devices of conjugated polymers can be small. In luminescence devices, such as light emitting diodes or fluorescence biosensors, there is a chance of interaction between conjugated molecules especially if more than one type of molecule is present. Quenching of the light and fluorescence energy transfer can occur and a simple approach to study this was developed.

    List of papers
    1. Hydrogels of a conducting conjugated polymer as 3-D enzyme electrode
    Open this publication in new window or tab >>Hydrogels of a conducting conjugated polymer as 3-D enzyme electrode
    2003 (English)In: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 19, no 3, p. 199-207Article in journal (Refereed) Published
    Abstract [en]

    We have utilized the highly conducting poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) aqueous dispersion (PEDOT/PSS) to build a conducting hydrogel matrix. Together with appropriate biomolecules this constitutes a hydrogel bio-electrode. The open hydrogel structure makes diffusion of analytes surrounding the cells into the matrix electrode easier. If enzymes are utilized, osmium is used as mediator between the prosthetic group of the enzyme and the conducting polymer matrix. Osmium also functions as a crosslink point to poly-4-vinylpyridine, which together with the magnesium crosslinked PEDOT/PSS gives a rigid hydrogel. The enzyme Horseradish peroxidase (HRP) was used as a model enzyme to evaluate the enzyme-enhanced electrode. We evaluated the electrode at pH 7, which is the pH choice for many biological systems. From cyclic voltammetry (CV) measurements we deduced that a very low reduction potential was needed to reduce the prosthetic group. Constant potential amperometry were performed to demonstrate the biosensor capabilities. A differential sensitivity of 0.13 A M−1 cm−2 through the 0–30 μM concentration range was achieved. Both the biostability and the influence on conductivity, important aspects when for example making nerve- or cell-electrodes, were investigated.

    Keywords
    Biomolecule electrode, Conjugated polymer, Horseradish peroxidase, Hydrogel, Osmium, PEDOT/PSS
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-46422 (URN)10.1016/S0956-5663(03)00220-3 (DOI)
    Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
    2. Hydrogels from a water-soluble Zwitterionic polythiophene: dynamics under pH change and biomolecular interactions observed using quartz crystal microbalance with dissipation monitoring
    Open this publication in new window or tab >>Hydrogels from a water-soluble Zwitterionic polythiophene: dynamics under pH change and biomolecular interactions observed using quartz crystal microbalance with dissipation monitoring
    2005 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 21, no 16, p. 7292-7298Article in journal (Refereed) Published
    Abstract [en]

    The water-soluble zwitterionic polythiophene, poly(3-((S)-5-amino-5- carboxyl-3-oxapentyl)-2,5-thiophene) hydrochloride (POWT), is a conjugated polyelectrolyte (CPE) with properties well suited for biochip applications. CPEs readily form hydrogels when exposed to water-based buffer solutions or biomolecule solutions. In this work, we used in situ quartz crystal microbalance with dissipation (QCM-D) monitoring to collect information on the interaction between POWT films exposed to buffers with different pH and POWT/DNA chains. Our data show that POWT swells significantly when exposed to low-pH buffers, such as pH 4 acetate, this is seen as an increase in thickness and decrease in viscosity obtained via a Voight-based modeling of combined f and D QCM-D measurements. The magnitude of thickness and viscosity change upon changing from a pH 10 carbonate buffer to pH 4 acetate is 100% increase in thickness and 50% decrease in viscosity. The response of the hydrogel under pH change is well correlated with fluorescence data from POWT films on glass. The state of the hydrogel is important during interaction with biomolecules; illustrated by the observation that a swollen CPE hydrogel adsorbs a higher amount of DNA than a compacted one. In agreement with previous results, the QCM-D data confirmed that the POWT/DNA hydrogel sense complementary DNA specifically and with negligible binding of noncomplementary DNA. These results are important for efficient constructions of biochips in water environments using this class of materials.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-12726 (URN)10.1021/la050479e (DOI)
    Available from: 2007-12-07 Created: 2007-12-07 Last updated: 2017-12-14
    3. Interactions between a zwitterionic polythiophene derivative and oligonucleotides as resolved by fluorescence resonance energy transfer
    Open this publication in new window or tab >>Interactions between a zwitterionic polythiophene derivative and oligonucleotides as resolved by fluorescence resonance energy transfer
    2005 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 17, no 16, p. 4204-4211Article in journal (Refereed) Published
    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.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-30356 (URN)10.1021/cm050328x (DOI)15901 (Local ID)15901 (Archive number)15901 (OAI)
    Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2017-12-13
    4. Fluorescence quenching and excitation transfer between semiconducting and metallic organic layers
    Open this publication in new window or tab >>Fluorescence quenching and excitation transfer between semiconducting and metallic organic layers
    2004 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 96, no 6, p. 3140-3147Article in journal (Refereed) Published
    Abstract [en]

    Here we present a simple approach to study the interaction of singlet excitons with polarons in conjugated polymers in organic electronic devices. Interlayer quenching constants KIL of 1.5 M−1 between a fluorescent molecule and a doped polymer in a layered sample demonstrates the importance of understanding the quenching of excited states in polymeric devices. A combination of Förster resonance energy transfer and quenching of photoluminescence between a fluorescent molecule and a conjugated polymer in its semiconducting and metallic states were studied. The polymer is a chiral 3-substituted polythiophene (POWT) and the fluorescent molecule is fluorescein bound to dextran (D-FITC). Bilayer samples with fluorescein on top of the POWT were fabricated and studied with absorption spectroscopy, fluorescence microscopy, and electrochemical doping methods. When POWT is electrochemically dedoped it is possible to enhance the photoluminescence in the polymer layer by excitation transfer from the fluorescein layer. Our results demonstrate that PL from the polythiophene disappears rapidly as soon as the layer is doped. As the doping of polymer layer increases the fluorescence from the fluorescein on top of the polymer decreases, due to excitation quenching. Models for excitation transfer and excitation quenching in POWT/FITC bilayer devices have been developed. This model predicts a linear relationship between the PL from the two molecules, in agreement with our experimental findings. These results are relevant for the development of electroluminescent devices or solar cells based on conjugated polymers.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-45631 (URN)10.1063/1.1774247 (DOI)
    Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
    5. Surface energy modified chips for detection of conformational states and enzymatic activity in biomolecules
    Open this publication in new window or tab >>Surface energy modified chips for detection of conformational states and enzymatic activity in biomolecules
    2006 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 22, no 5, p. 2205-2211Article in journal (Refereed) Published
    Abstract [en]

    A novel patterning method for anchoring biomolecules and noncovalent assembled conjugated polyelectrolyte (CPE)/biomolecule complexes to a chip surface is presented. The surface energy of a hydrophilic substrate is modified using an elastomeric poly(dimethylsiloxane) (PDMS) stamp, containing a relief pattern. Modification takes place on the parts where the PDMS stamp is in conformal contact with the substrate and leaves low molecular weight PDMS residues on the surface resulting in a hydrophobic modification, and then biomolecules and CPE/biomolecule complexes are then adsorbed in a specific pattern. The method constitutes a discrimination system for different conformations in biomolecules using CPEs as reporters and the PDMS modified substrates as the discriminator. Detection of different conformations in two biomacromolecules, a synthetic peptide (JR2E) and a protein (calmodulin), reported by the CPE and resolved by fluorescence was demonstrated. Also, excellent enzyme activity in patterned CPE/horseradish peroxidase (HRP) enzyme was shown, demonstrating that this method can be used to pattern biomolecules with their activity retained. The method presented could be useful in various biochip applications, such as analyzing proteins and peptides in large-scale production, in making metabolic chips, and for making multi-microarrays.

    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-34580 (URN)10.1021/la0527902 (DOI)22009 (Local ID)22009 (Archive number)22009 (OAI)
    Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13
  • 750.
    Åsberg, Peter
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Björk, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Höök, Fredrik
    Solid State Physics, Lund University, Lund, Sweden .
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Hydrogels from a water-soluble Zwitterionic polythiophene: dynamics under pH change and biomolecular interactions observed using quartz crystal microbalance with dissipation monitoring2005In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 21, no 16, p. 7292-7298Article in journal (Refereed)
    Abstract [en]

    The water-soluble zwitterionic polythiophene, poly(3-((S)-5-amino-5- carboxyl-3-oxapentyl)-2,5-thiophene) hydrochloride (POWT), is a conjugated polyelectrolyte (CPE) with properties well suited for biochip applications. CPEs readily form hydrogels when exposed to water-based buffer solutions or biomolecule solutions. In this work, we used in situ quartz crystal microbalance with dissipation (QCM-D) monitoring to collect information on the interaction between POWT films exposed to buffers with different pH and POWT/DNA chains. Our data show that POWT swells significantly when exposed to low-pH buffers, such as pH 4 acetate, this is seen as an increase in thickness and decrease in viscosity obtained via a Voight-based modeling of combined f and D QCM-D measurements. The magnitude of thickness and viscosity change upon changing from a pH 10 carbonate buffer to pH 4 acetate is 100% increase in thickness and 50% decrease in viscosity. The response of the hydrogel under pH change is well correlated with fluorescence data from POWT films on glass. The state of the hydrogel is important during interaction with biomolecules; illustrated by the observation that a swollen CPE hydrogel adsorbs a higher amount of DNA than a compacted one. In agreement with previous results, the QCM-D data confirmed that the POWT/DNA hydrogel sense complementary DNA specifically and with negligible binding of noncomplementary DNA. These results are important for efficient constructions of biochips in water environments using this class of materials.

1213141516 701 - 750 of 754
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf