liu.seSök publikationer i DiVA
Ändra sökning
Avgränsa sökresultatet
12 1 - 50 av 70
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Bai, Sai
    et al.
    Zhejiang University, Peoples R China .
    Cao, Motao
    Zhejiang University, Peoples R China .
    Jin, Yizheng
    Zhejiang University, Peoples R China Zhejiang University, Peoples R China Zhejiang University, Peoples R China .
    Dai, Xinliang
    Zhejiang University, Peoples R China .
    Liang, Xiaoyong
    Zhejiang University, Peoples R China .
    Ye, Zhizhen
    Zhejiang University, Peoples R China Zhejiang University, Peoples R China .
    Li, Min
    Zhejiang University, Peoples R China .
    Cheng, Jipeng
    Zhejiang University, Peoples R China .
    Xiao, Xuezhang
    Zhejiang University, Peoples R China .
    Wu, Zhongwei
    Soochow University, Peoples R China .
    Xia, Zhouhui
    Soochow University, Peoples R China .
    Sun, Baoquan
    Soochow University, Peoples R China .
    Wang, Ergang
    Chalmers, Sweden .
    Mo, Yueqi
    S China University of Technology, Peoples R China .
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Zhang, Fengling
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Low-Temperature Combustion-Synthesized Nickel Oxide Thin Films as Hole-Transport Interlayers for SolutionProcessed Optoelectronic Devices2014Ingår i: ADVANCED ENERGY MATERIALS, ISSN 1614-6832, Vol. 4, nr 6Artikel i tidskrift (Refereegranskat)
    Abstract [en]

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

  • 2.
    Bai, Sai
    et al.
    Zhejiang University, Peoples R China.
    He, Shasha
    Zhejiang University, Peoples R China.
    Jin, Yizheng
    Zhejiang University, Peoples R China.
    Wu, Zhongwei
    Soochow University, Peoples R China.
    Xia, Zhouhui
    Soochow University, Peoples R China.
    Sun, Baoquan
    Soochow University, Peoples R China.
    Wang, Xin
    Zhejiang University, Peoples R China.
    Ye, Zhizhen
    Zhejiang University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Shao, Shuyan
    Zhang, Fengling
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Electrophoretic deposited oxide thin films as charge transporting interlayers for solution-processed optoelectronic devices: the case of ZnO nanocrystals2015Ingår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 5, nr 11, s. 8216-8222Artikel i tidskrift (Refereegranskat)
    Abstract [en]

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

  • 3.
    Bai, Sai
    et al.
    Zhejiang University, Peoples R China; Zhejiang University, Peoples R China.
    Jin, Yizheng
    Zhejiang University, Peoples R China; Zhejiang University, Peoples R China.
    Liang, Xiaoyong
    Zhejiang University, Peoples R China; Zhejiang University, Peoples R China.
    Ye, Zhizhen
    Zhejiang University, Peoples R China; Zhejiang University, Peoples R China.
    Wu, Zhongwei
    Soochow University, Peoples R China.
    Sun, Baoquan
    Soochow University, Peoples R China.
    Ma, Zaifei
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Tang, Zheng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Wang, Jianpu
    Nanjing Technical University, Peoples R China.
    Wuerfel, Uli
    Fraunhofer Institute Solar Energy Syst ISE, Germany; University of Freiburg, Germany.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Zhang, Fengling
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Ethanedithiol Treatment of Solution-Processed ZnO Thin Films: Controlling the Intragap States of Electron Transporting Interlayers for Efficient and Stable Inverted Organic Photovoltaics2015Ingår i: ADVANCED ENERGY MATERIALS, ISSN 1614-6832, Vol. 5, nr 5, s. 1401606-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

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

  • 4.
    Bai, Sai
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Yuan, Zhongcheng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Colloidal metal halide perovskite nanocrystals: synthesis, characterization, and applications2016Ingår i: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 4, nr 18, s. 3898-3904Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Colloidal metal halide perovskite nanocrystals (NCs) have emerged as promising materials for optoelectronic devices and received considerable attention recently. Their superior photoluminescence (PL) properties provide significant advantages for lighting and display applications. In this Highlight, we discuss recent developments in the design and chemical synthesis of colloidal perovskite NCs, including both organic-inorganic hybrid and all inorganic perovskite NCs. We review the excellent PL properties and current optoelectronic applications of these perovskite NCs. In addition, critical challenges that currently limit the applicability of perovskite NCs are discussed, and prospects for future directions are proposed.

  • 5.
    Bakulin, Artem A.
    et al.
    FOM Institute AMOLF, Netherlands; University of Cambridge, England.
    Xia, Yuxin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Bakker, Huib J.
    FOM Institute AMOLF, Netherlands.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Morphology, Temperature, and Field Dependence Separation in High-Efficiency Solar Cells Based on Polyquinoxaline Copolymer2016Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 120, nr 8, s. 4219-4226Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Charge separation and recombination are key processes determining the performance of organic optoelectronic devices. Here we combine photoluminescence and photovoltaic characterization of organic solar cell devices with ultrafast multipulse photocurrent spectroscopy to investigate charge generation mechanisms in the organic photovoltaic devices based on a blend of an alternating polyquinoxaline copolymer with fullerene. The combined use of these techniques enables the determination of the contributions of geminate and bimolecular processes to the solar cell performance. We observe that charge separation is not a temperature-activated process in the studied materials. At the same time, the generation of free charges shows a dear external field and morphology dependence. This indicates that the critical step of charge separation involves the nonequilibrium state that is formed at early times after photoexcitation, when the polaronic localization is not yet complete. This work reveals new aspects of molecular level charge dynamics in the organic light-conversion systems.

  • 6.
    Bao, Qinye
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Liu, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Braun, Slawomir
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Fahlman, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Energetics at Doped Conjugated Polymer/Electrode Interfaces2015Ingår i: ADVANCED MATERIALS INTERFACES, ISSN 2196-7350, Vol. 2, nr 2Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    n/a

  • 7.
    Bao, Qinye
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Liu, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Wang, Ergang
    Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, Sweden.
    Fang, Junfeng
    Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science, Ningbo, PR China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten. State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, P. R. China.
    Braun, Slawomirslama19
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Fahlman, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Regular Energetics at Conjugated Electrolyte/Electrode Modifier for Organic Electronics and Their Implications of Design Rules2015Ingår i: Advanced Materials Interfaces, ISSN 2196-7350, Vol. 2, nr 12, s. 1-6, artikel-id 1500204Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Regular energetics at a conjugated electrolyte/electrode modifier are found and controlled by equilibration of the Fermi level and an additional interface double dipole step induced by ionic functionality. Based on the results, design rules for conjugated electrolyte/electrode modifiers to achieve the smallest charge injection/exaction barrier and break through the current thickness limitation are proposed.

  • 8.
    Bao, Qinye
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Liu, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Xia, Yuxin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Kauffmann, Louis-Dominique
    GenesInk, France.
    Margeat, Olivier
    Aix Marseille University, France.
    Ackermann, Jorg
    Aix Marseille University, France.
    Fahlman, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska högskolan.
    Effects of ultraviolet soaking on surface electronic structures of solution processed ZnO nanoparticle films in polymer solar cells2014Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2, nr 41, s. 17676-17682Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We systematically show the effect of UV-light soaking on surface electronic structures and chemical states of solution processed ZnO nanoparticle (ZnONP) films in UHV, dry air and UV-ozone. UV exposure in UHV induces a slight decrease in work function and surface-desorption of chemisorbed oxygen, whereas UV exposure in the presence of oxygen causes an increase in work function due to oxygen atom vacancy filling in the ZnO matrix. We demonstrate that UV-light soaking in combination with vacuum or oxygen can tune the work function of the ZnONP films over a range exceeding 1 eV. Based on photovoltaic performance and diode measurements, we conclude that the oxygen atom vacancy filling occurs mainly at the surface of the ZnONP films and that the films consequently retain their n-type behavior despite a significant increase in the measured work function.

  • 9.
    Chen, K.
    et al.
    Nanjing University, Peoples R China.
    Li, G. L.
    Nanjing University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Liu, J.
    Nanjing University, Peoples R China.
    Liu, J. M.
    Nanjing University, Peoples R China.
    Zhu, J. S.
    Nanjing University, Peoples R China.
    Conducting grain boundaries in the high-dielectric-constant ceramic CaCu3Ti4O122007Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 101, nr 7, s. 074101-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To clarify the electrical property of grain boundaries, the fine-grained ceramics CaCu3Ti4O12 have been treated with the hydrofluoric acid to remove the parts of grain boundaries. The dielectric response difference between the etched samples and the pristine ones indicates that the ceramic CaCu3Ti4O12 consists of insulating or semiconducting grains with conducting grain boundaries. Therefore, the giant dielectric phenomenon is supposed not to derive from the grain boundary barrier layer capacitance effect. The possible mechanism is discussed. (c) 2007 American Institute of Physics.

  • 10.
    Chen, K.
    et al.
    Nanjing University, Peoples R China.
    Liu, Y. F.
    Nanjing University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Du, Z. L.
    Nanjing University, Peoples R China.
    Liu, J. M.
    Nanjing University, Peoples R China.
    Ying, X. N.
    Nanjing University, Peoples R China.
    Lu, X. M.
    Nanjing University, Peoples R China.
    Zhu, J. S.
    Nanjing University, Peoples R China.
    Ti deficiency effect on the dielectric response of CaCu3Ti4O12 ceramics2007Ingår i: Solid State Communications, ISSN 0038-1098, E-ISSN 1879-2766, Vol. 141, nr 8, s. 440-444Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Single phase ceramics CaCu3Ti4.0O12 and CaCu3Ti3.9O12 have been prepared using the traditional solid-state reaction method. Compared with the stoichiometric ceramics CaCu3Ti4.0O12, Ti-deficient ceramics CaCu3Ti3.9O12 have the larger lattice parameter, the higher force constant, and smaller dielectric constant and the lower dissipation factor, although their fundamental characters of dielectric response are similar. Their characteristic relaxation frequencies are not well fitted with the Arrhenius Law but a tentatively supposed relation. With the Cole-Cole Law, the fitted broadened factors of dissipation peaks are 0.5433 and 0.8651 for CaCu3Ti3.9O12 and CaCu3Ti4.0O12, respectively. All facts mentioned above imply that mutually correlated motion of Ti ions or defects may be expected to be responsible for the giant dielectric constant and high dissipation factor of CaCu3T4.0O12. (c) 2006 Elsevier Ltd. All rights reserved.

  • 11.
    Chen, K.
    et al.
    Nanjing University, Peoples R China.
    Yuan, S. K.
    Nanjing University, Peoples R China.
    Li, P. L.
    Nanjing University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Liu, J.
    Nanjing University, Peoples R China.
    Li, G. L.
    Nanjing University, Peoples R China.
    Zhao, A. G.
    Nanjing University, Peoples R China.
    Lu, X. M.
    Nanjing University, Peoples R China.
    Liu, J. M.
    Nanjing University, Peoples R China.
    Zhu, J. S.
    Nanjing University, Peoples R China.
    High permittivity in zr doped NiO ceramics2007Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 102, nr 3, s. 034103-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report on measurements of the dielectric permittivity of NiO-based ceramics doped with Zr (ZNO). Samples were prepared by the traditional solid-state reaction method. The concentration of Zr has an effect on the dielectric properties of ZNO ceramics. High permittivity values (similar to 10(4)) were observed which remain almost constant from 200 K to 350 K at low frequencies. The high-dielectric-constant response of the ZNO ceramics is attributed mainly to a grain boundary (internal) barrier layer capacitance. (c) 2007 American Institute of Physics.

  • 12.
    Chen, Kai
    et al.
    Nanjing University, Peoples R China; Nanjing University, Peoples R China; Nanjing University of Science and Technology, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Lin, Weiwei
    Nanjing University, Peoples R China; Nanjing University, Peoples R China.
    Cai, Hongling
    Nanjing University, Peoples R China; Nanjing University, Peoples R China.
    Li, Guolin
    Nanjing University, Peoples R China; Nanjing University, Peoples R China.
    Dong, Xingwei
    Nanjing University, Peoples R China; Nanjing University, Peoples R China.
    Peng, Song
    Nanjing University, Peoples R China; Nanjing University, Peoples R China.
    Wu, Xiaoshan
    Nanjing University, Peoples R China; Nanjing University, Peoples R China.
    Yang, Mao
    Nanjing University, Peoples R China; Nanjing University, Peoples R China.
    Du, Jun
    Nanjing University, Peoples R China; Nanjing University, Peoples R China.
    Lu, Xiaomei
    Nanjing University, Peoples R China; Nanjing University, Peoples R China.
    Liu, Junming
    Nanjing University, Peoples R China; Nanjing University, Peoples R China.
    Zhu, Jinsong
    Nanjing University, Peoples R China; Nanjing University, Peoples R China.
    Room-temperature multiferroic properties in NiBi2O42010Ingår i: Europhysics letters, ISSN 0295-5075, E-ISSN 1286-4854, Vol. 89, nr 2, artikel-id 27004Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Magnetism and ferroelectricity at room temperature are observed in the NiBi2O4 ceramics. Both the time reversal and the inversion symmetry of the structure (space group F-43m) are broken. The saturation magnetization is 0.028 emu/g and the saturation polarization 2P(s) similar to 4.0 mu C/cm(2). NiBi2O4 also shows other room-temperature multiferroic properties, e. g. the piezoelectric coefficient (d(33)), the polarized dielectric character, the magneto-dielectric response and the magnetoelectric effect. Copyright (C) EPLA, 2010

  • 13.
    Chen, Kai
    et al.
    Nanjing University of Science and Technology, Peoples R China; Nanjing University, Peoples R China.
    Guo, Rui
    Nanjing University of Science and Technology, Peoples R China.
    Ma, Chunguang
    Nanjing University of Science and Technology, Peoples R China.
    Dai, Tingyang
    Nanjing University, Peoples R China.
    Ye, Sunjie
    Nanjing University, Peoples R China.
    Lu, Yun
    Nanjing University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Zhu, Jinsong
    Nanjing University, Peoples R China.
    Jiang, Wei
    Nanjing University of Science and Technology, Peoples R China.
    Self-Assembled Core-Shell Polymer Dielectric Prepared by Solution Casting Process2009Ingår i: Integrated Ferroelectrics, ISSN 1058-4587, E-ISSN 1607-8489, Vol. 113, s. 1-8Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Giant permittivity at 1 MHz, which slightly changes with temperatures, is observed in a polymer composite. The dielectric spectroscopy demonstrates that the samples are electrically heterogeneous. The microstructure observation and the ingredient analysis evidence they self assemble the conducting cores surrounded by the insulating shells. The giant-dielectric phenomenon is therefore attributed to the percolation effect. The electrically heterogeneous microstructure with effective permittivity values about 10 000 can be fabricated by a simple solution casting process in air. The composite is an attractive option to the currently used printing dielectric and the future flexible electronics.

  • 14.
    Chen, X. Y.
    et al.
    Nanjing University, Peoples R China.
    Yu, T.
    Nanjing University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Zhang, H. T.
    Nanjing University, Peoples R China.
    Liu, L. F.
    Nanjing University, Peoples R China.
    Wang, Y. M.
    Nanjing University, Peoples R China.
    Li, Z. S.
    Nanjing University, Peoples R China.
    Zou, Z. G.
    Nanjing University, Peoples R China.
    Liu, J.-M.
    Nanjing University, Peoples R China.
    Application of weak ferromagnetic BiFeO3 films as the photoelectrode material under visible-light irradiation2007Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 91, nr 2, s. 022114-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BiFeO3 films prepared by pulsed laser deposition on Pt/TiO2/SiO2/Si substrates were studied as photoelectrode for water splitting. Under visible-light irradiation, the photocurrent intensity of the polycrystalline BiFeO3 film was found to double that of the amorphous one in a three-electrode cell. The incident photon to current conversion efficiency for the polycrystalline BiFeO3 electrode was approximately 16% at 350 nm and 7% at 530 nm at 1.5 V (versus saturated calomel electrode). The ferromagnetism of the amorphous BiFeO3 film was an order of magnitude weaker than that of the polycrystalline one, supporting the "size effect" explanation for magnetic origin. (C) 2007 American Institute of Physics.

  • 15.
    Chen, Zhuoying
    et al.
    University of Cambridge, England.
    Fang, Junfeng
    University of Cambridge, England.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Brenner, Thomas J. K.
    University of Cambridge, England.
    Banger, Kulbinder K.
    University of Cambridge, England.
    Wang, Xingzhu
    University of Cambridge, England.
    Huck, Wilhelm T. S.
    Radboud University of Nijmegen, Netherlands; University of Cambridge, England.
    Sirringhaus, Henning
    University of Cambridge, England.
    Enhanced charge transport by incorporating additional thiophene units in the poly(fluorene-thienyl-benzothiadiazole) polymer2011Ingår i: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 12, nr 3, s. 461-471Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report a comparative study of optical properties, structure and morphology, field-effect transistor (FET) and solar cell performance between poly(4-(3,4-dihexyl-2,2-bithiophen-5-yl)-7-(5-(9,9-dioctyl-9H-fluoren-2-yl)-3,4-dihexyl-2,2-bithiophen-5-yl)benzo[c][1,2,5]-thiadiazole) (F8TTBTT), and its predecessor poly((9,9-dioctylfluorene)-2,7-diyl-alt[4,7-bis(3-hexylthien-5-yl)-2,1,3-benzothiadiazole]-2,2 -diyl) (F8TBT). Compared to F8TBT, F8TTBTT has two more thiophene units incorporated in its monomer structure. Such a modification leads to a reduced optical band gap, improved charge injection and significantly enhanced ambipolar field-effect mobilities reaching 5 x 10 (2) cm(2) V (1) s (1) for holes and 4 x 10 (3) cm(2) V (1) s (1) for electrons. The enhanced carrier mobilities are most likely a result of an increased backbone planarization and interchain interaction. As a consequence of ambipolar transport, light-emission was observed from the transistor channel during operation. The reduced band gap and improved charge transport make F8TTBTT an interesting candidate also for solar cell applications. Unoptimized solar cells based on F8TTBTT: PCBM blends were found to exhibit power conversion efficiency under AM 1.5 illumination of similar to 1.54%. (C) 2011 Published by Elsevier B.V.

  • 16.
    Dai, Tingyang
    et al.
    Nanjing University, Peoples R China.
    Chen, Kai
    Nanjing University of Science and Technology, Peoples R China.
    Qing, Xutang
    Nanjing University, Peoples R China.
    Lu, Yun
    Nanjing University, Peoples R China.
    Zhu, Jinsong
    Nanjing University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Sequential Polymer Precipitation of Core-Shell Microstructured Composites with Giant Permittivity2010Ingår i: Macromolecular rapid communications, ISSN 1022-1336, E-ISSN 1521-3927, Vol. 31, nr 5, s. 484-489Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polymeric core shell microstructures have been constructed through a new method, namely sequential precipitation, which is intrinsically a self-assembly and phase separation process. High-quality poly(vinyldene fluoride)-polycarbonate-lithium perchlorate composite films with spherical core shell microstructures have been prepared and determined to consist of conducting cores and insulating shells. Because of the percolation effect, the resulting materials present a dielectric constant as high as 10(4)-10(7) at the threshold.

  • 17.
    Dong, S.
    et al.
    Nanjing University, MA 02460 USA.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Wang, Z. Q.
    Nanjing University, MA 02460 USA.
    Liu, J. -M.
    Nanjing University, MA 02460 USA.
    Ren, Z. F.
    Nanjing University, MA 02460 USA.
    Surface phase separation in nanosized charge-ordered manganites2007Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 90, nr 8, s. 082508-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recent experiments showed that the robust charge ordering in manganites can be weakened by reducing the grain size down to nanoscale. Weak ferromagnetism was evidenced in both nanoparticles and nanowires of charge-ordered manganites. To explain these observations, a phenomenological model based on surface phase separation is proposed. The relaxation of superexchange interaction on the surface layer allows formation of a ferromagnetic shell, whose thickness increases with decreasing grain size. Possible exchange bias and softening of the ferromagnetic transition in nanosized charge-ordered manganites are predicted. (c) 2007 American Institute of Physics.

  • 18.
    Fang, Junfeng
    et al.
    University of Cambridge, England.
    Wallikewitz, Bodo H.
    University of Cambridge, England.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Tu, Guoli
    University of Cambridge, England; Huazhong University of Science and Technology, Peoples R China.
    Mueller, Christian
    University of Cambridge, England.
    Pace, Giuseppina
    University of Cambridge, England.
    Friend, Richard H.
    University of Cambridge, England.
    Huck, Wilhelm T. S.
    University of Cambridge, England; Radboud University of Nijmegen, Netherlands.
    Conjugated Zwitterionic Polyelectrolyte as the Charge Injection Layer for High-Performance Polymer Light-Emitting Diodes2011Ingår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 133, nr 4, s. 683-685Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new zwitterionic conjugated polyelectrolyte without free counterions has been used as an electron injection material in polymer light-emitting diodes. Both the efficiency and maximum brightness were considerably improved in comparison with standard Ca cathode devices. The devices showed very fast response times, indicating that the improved performance is, in addition to hole blocking, due to dipoles at the cathode interface, which facilitate electron injection.

  • 19.
    Gao, Feng
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Cai, C.
    Nanjing University, Peoples R China.
    Wang, Y.
    Nanjing University, Peoples R China.
    Dong, S.
    Nanjing University, Peoples R China.
    Qiu, X. Y.
    Nanjing University, Peoples R China.
    Yuan, G. L.
    Nanjing University, Peoples R China.
    Liu, Z. G.
    Nanjing University, Peoples R China.
    Liu, J. -M.
    Nanjing University, Peoples R China.
    Preparation of la-doped BiFeO3 thin films with Fe2+ ions on Si substrates2006Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 99, nr 9, s. 094105-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    La-doped BiFeO3 thin films with Fe2+ ions have been prepared on Pt/TiO2/SiO2/Si substrates by pulsed laser deposition in order to enhance the ferroelectric and magnetic properties. The targets for the film deposition were synthesized using a rapid liquid phase sintering technique to ensure the low leakage. The dielectric properties at room temperature and above were investigated. It was observed that the La doping greatly enhances the ferroelectric polarization at room temperature by modifying the film structure from rhombohedral to monoclinic. The saturation magnetization was enhanced about two times due to the Fe2+ ions in the thin films. (C) 2006 American Institute of Physics.

  • 20.
    Gao, Feng
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Chen, Xinyi
    Nanjing University, China.
    Yin, Kuibo
    Nanjing University, China.
    Dong, Shuai
    Nanjing University, China.
    Ren, Zhifeng
    Boston College, USA.
    Yuan, Fang
    Nanjing University, China.
    Yu, Tao
    Nanjing University, China.
    Zou, Zhigang
    Nanjing University, China.
    Liu, Jun-Ming
    Nanjing University, China.
    Visible-light photocatalytic properties of weak magnetic BiFeO3 nanoparticles2007Ingår i: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 19, nr 19, s. 2889-2892Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Polycrystalline BiFeO3 nanoparticles (size 80-120 nm) are prepared by a simple sol-gel technique. Such nanoparticles are very efficient for photocatalytic decomposition of organic contaminants under irradiation from ultraviolet to visible frequencies. The BiFeO3 nanoparticles also demonstrate weak ferromagnetism of about 0.06 mu(B)/Fe at room temperature, in good agreement with theoretical calculations.

  • 21.
    Gao, Feng
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Himmelberger, Scott
    Stanford University, CA 94305 USA.
    Andersson, Mattias
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Hanifi, David
    Stanford University, CA 94305 USA.
    Xia, Yuxin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Zhang, Shaoqing
    Chinese Academic Science, Peoples R China.
    Wang, Jianpu
    Nanjing Technical University, Peoples R China; Nanjing Technical University, Peoples R China.
    Hou, Jianhui
    Chinese Academic Science, Peoples R China.
    Salleo, Alberto
    Stanford University, CA 94305 USA.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    The Effect of Processing Additives on Energetic Disorder in Highly Efficient Organic Photovoltaics: A Case Study on PBDTTT-C-T:PC71BM2015Ingår i: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 27, nr 26, s. 3868-3873Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Energetic disorder, an important parameter affecting the performance of organic photovoltaics, is significantly decreased upon the addition of processing additives in a highly efficient benzodithiophene-based copolymer blend (PBDTTT-C-T:PC71BM). Wide-angle and small-angle X-ray scattering measurements suggest that the origin of this reduced energetic disorder is due to increased aggregation and a larger average fullerene domain size together with purer phases.

  • 22.
    Gao, Feng
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Charge generation in polymer-fullerene bulk-heterojunction solar cells2014Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 16, nr 38, s. 20291-20304Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Charge generation in organic solar cells is a fundamental yet heavily debated issue. This article gives a balanced review of different mechanisms proposed to explain efficient charge generation in polymer-fullerene bulk-heterojunction solar cells. We discuss the effect of charge-transfer states, excess energy, external electric field, temperature, disorder of the materials, and delocalisation of the charge carriers on charge generation. Although a general consensus has not been reached yet, recent findings, based on both steady-state and transient measurements, have significantly advanced our understanding of this process.

  • 23.
    Gao, Feng
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Li, P. L.
    Nanjing University, China.
    Weng, Y. Y.
    Nanjing University, China.
    Dong, S.
    Nanjing University, China.
    Wang, L. F.
    Nanjing University, China.
    Lv, L. Y.
    Nanjing University, China.
    Wang, K. F.
    Nanjing University, China.
    Liu, J.-M.
    Nanjing University, China.
    Ren, Z. F.
    Nanjing University, MA 02467 USA.
    Charge order suppression and weak ferromagnetism in La1/3Sr2/3FeO3 nanoparticles2007Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 91, nr 7, s. 072504-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Perovskite-type polycrystalline La1/3Sr2/3FeO3 particles with different sizes (80-2000 nm) were prepared using a simple sol-gel technique. In samples of nanoparticles with a diameter of less than 300 nm, weak ferromagnetism was observed at room temperature, which was attributed to the lattice distortion. The magnetic and specific heat measurements suggest that the charge ordering state was largely suppressed due to the lowering of the particle size, but the charge ordering temperature remained unaffected. (C) 2007 American Institute of Physics.

  • 24.
    Gao, Feng
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Li, Zhe
    University of Cambridge, England.
    Wang, Jianpu
    University of Cambridge, England.
    Rao, Akshay
    University of Cambridge, England.
    Howard, Ian A.
    University of Cambridge, England.
    Abrusci, Agnese
    University of Cambridge, England.
    Massip, Sylvain
    University of Cambridge, England.
    McNeill, Christopher R.
    University of Cambridge, England.
    Greenham, Neil C.
    University of Cambridge, England.
    Trap-Induced Losses in Hybrid Photovoltaics2014Ingår i: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 8, nr 4, s. 3213-3221Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate the loss mechanisms in hybrid photovoltaics based on blends of poly(3-hexylthiophene) with CdSe nanocrystals of various sizes. By combining the spectroscopic and electrical measurements on working devices as well as films, we identify that high trap-mediated recombination is responsible for the loss of photogenerated charge carriers in devices with small nanocrystals. In addition, we demonstrate that the reduced open-circuit voltage for devices with small nanocrystals is also caused by the traps.

  • 25.
    Gao, Feng
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Qiu, X. Y.
    Nanjing University, Peoples R China.
    Yuan, Y.
    Nanjing University, Peoples R China.
    Xu, B.
    Nanjing University, Peoples R China.
    Wen, Y. Y.
    Nanjing University, Peoples R China.
    Yuan, F.
    Nanjing University, Peoples R China.
    Lv, L. Y.
    Nanjing University, Peoples R China.
    Liu, J.-M.
    Nanjing University, Peoples R China.
    Effects of substrate temperature on Bi0.8La0.2FeO3 thin films prepared by pulsed laser deposition2007Ingår i: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731, Vol. 515, nr 13, s. 5366-5373Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Bi0.8La0.2FeO3 thin films on Pt/TiO2/SiO2/Si substrates at various substrate temperatures from 500 degrees C to 750 degrees C are prepared by pulsed laser deposition, and their microstructures and ferroelectric/magnetic properties are carefully investigated using various techniques. It is observed that the crystallographic orientation and Fe-ion valence state depend significantly on the substrate temperature, which consequently influences considerably on the ferroelectric and magnetic properties of the thin films. A considerable improvement of the ferroelectric and magnetic properties of the thin films can be achieved by optimizing the substrate temperature for deposition. (C) 2007 Elsevier B.V. All rights reserved.

  • 26.
    Gao, Feng
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Ren, Shenqiang
    University of Kansas, USA.
    Wang, Jianpu
    University of Cambridge, England.
    The renaissance of hybrid solar cells: progresses, challenges, and perspectives2013Ingår i: Energy & Environmental Science, ISSN 1754-5692, E-ISSN 1754-5706, Vol. 6, nr 7, s. 2020-2040Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Solution-processed hybrid solar cells, a blend of conjugated polymers and semiconducting nanocrystals, are a promising candidate for next-generation energy-conversion devices. The renaissance of this field in recent years has yielded a much deeper understanding of optoelectronic interactions in organic–inorganic hybrid systems. In this article, we review the state-of-the-art progress in hybrid bulk heterojunction solar cells, covering new materials design, interfacial interaction, and processing control. Furthermore, critical challenges that determine photovoltaic performance and prospects for future directions are discussed.

  • 27.
    Gao, Feng
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan. University of Cambridge, England.
    Tress, Wolfgang
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Wang, Jianpu
    University of Cambridge, England; Nanjing Technical University, Peoples R China; Nanjing Technical University, Peoples R China.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Temperature Dependence of Charge Carrier Generation in Organic Photovoltaics2015Ingår i: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 114, nr 12, s. 128701-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The charge generation mechanism in organic photovoltaics is a fundamental yet heavily debated issue. All the generated charges recombine at the open-circuit voltage (VOC), so that investigation of recombined charges at VOC provides a unique approach to understanding charge generation. At low temperatures, we observe a decrease of VOC, which is attributed to reduced charge separation. Comparison between benchmark polymer: fullerene and polymer: polymer blends highlights the critical role of charge delocalization in charge separation and emphasizes the importance of entropy in charge generation.

  • 28.
    Gao, Feng
    et al.
    University of Cambridge, England.
    Wang, Jianpu
    University of Cambridge, England.
    Blakesley, James C.
    University of Potsdam, Germany.
    Hwang, Inchan
    University of Cambridge, England.
    Li, Zhe
    University of Cambridge, England.
    Greenham, Neil C.
    University of Cambridge, England.
    Quantifying Loss Mechanisms in Polymer:Fullerene Photovoltaic Devices2012Ingår i: ADVANCED ENERGY MATERIALS, ISSN 1614-6832, Vol. 2, nr 8, s. 956-961Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    n/a

  • 29.
    Gao, Feng
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Yuan, Y.
    Nanjing University, 210093 China.
    Wang, K. F.
    Nanjing University, 210093 China.
    Chen, X. Y.
    Nanjing University, 210093 China.
    Chen, F.
    Nanjing University, 210093 China.
    Liu, J. -M.
    Nanjing University, 210093 China.
    Preparation and photoabsorption characterization of BiFeO3 nanowires2006Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 89, nr 10, s. 102506-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Perovskite-type polycrystalline BiFeO3 (BFO) nanowires (similar to 50 nm in diameter and similar to 5 mu m in length) were synthesized using the anodized alumina template technique. An energy band gap of similar to 2.5 eV was determined from the UV-visible diffuse reflectance spectrum, and its photocatalytic ability to produce O-2 was revealed under UV irradiation. Weak ferromagnetism at room temperature and superparamagnetism at low temperature were observed for the BFO nanowires, different from the antiferromagnetic order in bulk BFO, reflecting the significant size effects on the magnetic ordering of BFO. (c) 2006 American Institute of Physics.

  • 30.
    He, Ximin
    et al.
    University of Cambridge, England; University of Cambridge, England.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Tu, Guoli
    University of Cambridge, England.
    Hasko, David G.
    University of Cambridge, England.
    Huettner, Sven
    University of Cambridge, England.
    Greenham, Neil C.
    University of Cambridge, England.
    Steiner, Ullrich
    University of Cambridge, England.
    Friend, Richard H.
    University of Cambridge, England.
    Huck, Wilhelm T. S.
    University of Cambridge, England; University of Cambridge, England; Radboud University of Nijmegen, Netherlands.
    Formation of Well-Ordered Heterojunctions in Polymer: PCBM Photovoltaic Devices2011Ingår i: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 21, nr 1, s. 139-146Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The nanoscale morphology in polymer:PCBM based photovoltaic devices is a major contributor to overall device performance. The disordered nature of the phase-separated structure, in combination with the small length scales involved and the inherent difficulty of reproducing the exact morphologies when spin-coating and annealing thin blend films, have greatly hampered the development of a detailed understanding of how morphology impacts photo voltaic device functioning. In this paper we demonstrate a double nanoimprinting process that allows the formation of nanostructured polymer: PCBM heterojunctions of composition and morphology that can be selected independently. We fabricated photovoltaic (PV) devices with extremely high densities (10(14) mm(-2)) of interpenetrating nanoscale columnar features (as small as 25 nm; at or below the exciton diffusion length) in the active layer. By comparing device results of different feature sizes and two different polymer: PCBM combinations, we demonstrate how double imprinting can be a powerful tool to systematically study different parameters in polymer photovoltaic devices.

  • 31.
    He, Ximin
    et al.
    University of Cambridge, England; University of Cambridge, England.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Tu, Guoli
    University of Cambridge, England.
    Hasko, David
    University of Cambridge, England.
    Huettner, Sven
    University of Cambridge, England.
    Steiner, Ullrich
    University of Cambridge, England; University of Freiburg, Germany.
    Greenham, Neil C.
    University of Cambridge, England.
    Friend, Richard H.
    University of Cambridge, England.
    Huck, Wilhelm T. S.
    University of Cambridge, England; University of Cambridge, England; Radboud University of Nijmegen, Netherlands.
    Formation of Nanopatterned Polymer Blends in Photovoltaic Devices2010Ingår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 10, nr 4, s. 1302-1307Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper, we demonstrate a double nanoimprinting process that allows the formation of nanostructured polymer heterojunctions of composition and morphology that can be selected independently. We fabricated photovoltaic (PV) devices with extremely high densities (10(14)/mm(2)) of interpenetrating nanoscale columnar features in the active polymer blend layer. The smallest feature sizes are as small as 25 nm on a 50 nm pitch, which results in a spacing of hererojunctions at or below the exciton diffusion length. Photovoltaic devices based on double-imprinted poly((9,9-dioctylfluorene)-2,7-diyl-alt-[4,7-bis(3-hexylthien-5-yl)-2,1,3-benzothiadiazole]-2,2 diyl) (F8TBT)/poly(3-hexylthiophene) (P3HT) films are among the best polymer polymer blend devices reported to date with a power conversion efficiency (PCE, eta(e)) of 1.9%.

  • 32.
    Hou, Jianhui
    et al.
    Chinese Acad Sci, Peoples R China.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Friend, Richard H.
    Cavendish Lab, England.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Organic solar cells based on non-fullerene acceptors2018Ingår i: Nature Materials, ISSN 1476-1122, E-ISSN 1476-4660, Vol. 17, nr 2, s. 119-128Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Organic solar cells (OSCs) have been dominated by donor: acceptor blends based on fullerene acceptors for over two decades. This situation has changed recently, with non-fullerene (NF) OSCs developing very quickly. The power conversion efficiencies of NF OSCs have now reached a value of over 13%, which is higher than the best fullerene-based OSCs. NF acceptors show great tunability in absorption spectra and electron energy levels, providing a wide range of new opportunities. The coexistence of low voltage losses and high current generation indicates that new regimes of device physics and photophysics are reached in these systems. This Review highlights these opportunities made possible by NF acceptors, and also discuss the challenges facing the development of NF OSCs for practical applications.

  • 33.
    Kroon, Renee
    et al.
    University of S Australia, Australia Chalmers, Sweden .
    Diaz de Zerio Mendaza, Amaia
    Chalmers, Sweden .
    Himmelberger, Scott
    Stanford University, CA 94305 USA .
    Bergqvist, Jonas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Backe, Olof
    Chalmers, Sweden .
    Couto Faria, Gregorio
    Stanford University, CA 94305 USA University of Sao Paulo, Brazil .
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Obaid, Abdulmalik
    Wake Forest University, NC 27106 USA .
    Zhuang, Wenliu
    Chalmers, Sweden .
    Gedefaw, Desta
    Chalmers, Sweden .
    Olsson, Eva
    Chalmers, Sweden .
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Salleo, Alberto
    Stanford University, CA 94305 USA .
    Muller, Christian
    Chalmers, Sweden .
    Andersson, Mats R.
    University of S Australia, Australia Chalmers, Sweden .
    A New Tetracyclic Lactam Building Block for Thick, Broad-Bandgap Photovoltaics2014Ingår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 136, nr 33, s. 11578-11581Artikel i tidskrift (Refereegranskat)
    Abstract [en]

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

  • 34.
    Li, Guangru
    et al.
    University of Cambridge, England.
    Wisnivesky Rocca Rivarola, Florencia
    University of Cambridge, England.
    Davis, Nathaniel J. L. K.
    University of Cambridge, England.
    Bai, Sai
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Jellicoe, Tom C.
    University of Cambridge, England.
    de la Pena, Francisco
    University of Cambridge, England.
    Hou, Shaocong
    University of Cambridge, England.
    Ducati, Caterina
    University of Cambridge, England.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Friend, Richard H.
    University of Cambridge, England.
    Greenham, Neil C.
    University of Cambridge, England.
    Tan, Zhi-Kuang
    University of Cambridge, England; National University of Singapore, Singapore; National University of Singapore, Singapore.
    Highly Efficient Perovskite Nanocrystal Light-Emitting Diodes Enabled by a Universal Crosslinking Method2016Ingår i: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 28, nr 18, s. 3528-+Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The preparation of highly efficient perovskite nanocrystal light-emitting diodes is shown. A new trimethylaluminum vapor-based crosslinking method to render the nanocrystal films insoluble is applied. The resulting near-complete nanocrystal film coverage, coupled with the natural confinement of injected charges within the perovskite crystals, facilitates electron-hole capture and give rise to a remarkable electroluminescence yield of 5.7%.

  • 35.
    Li, P. L.
    et al.
    Nanjing University, MA 02467 USA.
    Yao, X. Y.
    Nanjing University, MA 02467 USA.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Zhao, C.
    Nanjing University, MA 02467 USA.
    Yin, K. B.
    Nanjing University, MA 02467 USA.
    Weng, Y. Y.
    Nanjing University, MA 02467 USA.
    Liu, J.-M.
    Nanjing University, MA 02467 USA.
    Ren, Z. F.
    Nanjing University, MA 02467 USA.
    Preparation of aligned Ca3Co2O6 nanorods and their steplike magnetization2007Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 91, nr 4, s. 042505-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Well-aligned Ca3Co2O6 nanorods (similar to 300 nm in length and similar to 40 nm in diameter) on Si substrates are prepared by pulsed laser deposition. The steplike magnetization feature as identified in bulk Ca3Co2O6 can be retained in the nanorods in spite of the enhanced distortion of the magnetically ordered spin chains due to the finite size effect. The out-of-plane magnetization value is slightly larger than the in-plane value, which shows the small magnetic anisotropy. An additional distinct transition at 54 K associated with the spin frustration is revealed, different from the bulk samples. (C) 2007 American Institute of Physics.

  • 36.
    Li, P. L.
    et al.
    Nanjing University, Peoples R China.
    Yao, X. Y.
    Nanjing University, Peoples R China.
    Wang, K. F.
    Nanjing University, Peoples R China.
    Lu, C. L.
    Nanjing University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Liu, J. -M.
    Nanjing University, Peoples R China.
    Steplike magnetocapacitance and dielectric relaxation in spin frustrated Ca(3)Co(2)O(6)2008Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 104, nr 5, s. 054111-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The dielectric relaxation and magnetocapacitance effect of one-dimensional spin frustrated compound Ca(3)Co(2)O(6) are investigated. The steplike magnetocapacitance effect is observed and one to one corresponds to the steplike magnetization. We explain this phenomenon from the spin configuration dependent dielectric response. The simulation results using the Monte Carlo method are in good agreement with experimental data at low temperature. The close correspondence between the magnetic and dielectric properties indicates that the coupling is the intrinsic character of Ca(3)Co(2)O. The steplike magnetocapacitance effect may find potential applications in data storage and sensors. (C) 2008 American Institute of Physics.

  • 37.
    Li, Xiaodong
    et al.
    Chinese Academic Science, Peoples R China; University of Chinese Academic Science, Peoples R China.
    Wang, Xueyan
    Chinese Academic Science, Peoples R China; University of Chinese Academic Science, Peoples R China.
    Zhang, Wenjun
    Chinese Academic Science, Peoples R China.
    Wu, Yulei
    Chinese Academic Science, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Fang, Junfeng
    Chinese Academic Science, Peoples R China.
    The effect of external electric field on the performance of perovskite solar cells2015Ingår i: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 18, s. 107-112Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Planar heterojunction perovskite solar cells were fabricated through a low temperature approach. We find that the device performance significantly depends on the external bias before and during measurements. By appropriate optimization of the bias conditions, we could achieve an 8-fold increase in the power conversion efficiency. The significant improvement in device performance might be caused by the ion motion in the perovskite under the external electric field.

  • 38.
    Li, Xiaodong
    et al.
    Chinese Academic Science, Peoples R China; University of Chinese Academic Science, Peoples R China.
    Zhang, Wenjun
    Chinese Academic Science, Peoples R China.
    Wang, Xueyan
    Chinese Academic Science, Peoples R China; University of Chinese Academic Science, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Fang, Junfeng
    Chinese Academic Science, Peoples R China.
    Disodium Edetate As a Promising Interfacial Material for Inverted Organic Solar Cells and the Device Performance Optimization2014Ingår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 6, nr 23, s. 20569-20573Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Disodium edetate (EDTA-Na), a popular hexadentate ligand in analytical chemistry, was successfully introduced in organic solar cells (OSCs) as cathode interfacial layer. The inverted OSCs with EDTA-Na showed superior performance both in power conversion efficiency and devices stability compared with conventional devices. Interestingly, we found that the performance of devices with EDTA-Na could be optimized through external bias treatment. After optimization, the efficiency of inverted OSCs with device structure of ITO/EDTA-Na/polymer thieno[3,4-b]thiophene/benzodithiophene (PTB7):PC71BM/MoO3/Al was significantly increased to 8.33% from an initial value of 6.75%. This work introduces a new class of interlayer materials, small molecule electrolytes, for organic solar cells.

  • 39.
    Li, Xiaodong
    et al.
    Chinese Academic Science, Peoples R China; University of Chinese Academic Science, Peoples R China.
    Zhang, Wenjun
    Chinese Academic Science, Peoples R China.
    Wang, Xueyan
    Chinese Academic Science, Peoples R China; University of Chinese Academic Science, Peoples R China.
    Wu, Yulei
    Chinese Academic Science, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Fang, Junfeng
    Chinese Academic Science, Peoples R China.
    Critical role of the external bias in improving the performance of polymer solar cells with a small molecule electrolyte interlayer2015Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 3, nr 2, s. 504-508Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A small-molecule electrolyte based on the popular ethylene diamine tetraacetic acid (EDTA-N) is introduced as an efficient cathode interlayer in inverted polymer solar cells, helping to deliver power conversion efficiency over 9%. The strong dependence of device performance on the external bias suggests that the ion motion plays a critical role in improving the performance of devices with electrolyte interlayers.

  • 40.
    Li, Yongxi
    et al.
    Soochow University, Peoples R China; Soochow University, Peoples R China; Chinese Academic Science, Peoples R China.
    Liu, Xiaodong
    Soochow University, Peoples R China.
    Wu, Fu-Peng
    Soochow University, Peoples R China.
    Zhou, Yi
    Soochow University, Peoples R China.
    Jiang, Zuo-Quan
    Soochow University, Peoples R China.
    Song, Bo
    Soochow University, Peoples R China.
    Xia, Yuxin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Zhang, Zhi-Guo
    Chinese Academic Science, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Li, Yongfang
    Soochow University, Peoples R China; Soochow University, Peoples R China; Chinese Academic Science, Peoples R China.
    Liao, Liang-Sheng
    Soochow University, Peoples R China.
    Non-fullerene acceptor with low energy loss and high external quantum efficiency: towards high performance polymer solar cells2016Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, nr 16, s. 5890-5897Artikel i tidskrift (Refereegranskat)
    Abstract [en]

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

  • 41.
    Li, Zhe
    et al.
    University of Cambridge, England.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Greenham, Neil C.
    University of Cambridge, England.
    McNeill, Christopher R.
    University of Cambridge, England.
    Comparison of the Operation of Polymer/Fullerene, Polymer/Polymer, and Polymer/Nanocrystal Solar Cells: A Transient Photocurrent and Photovoltage Study2011Ingår i: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 21, nr 8, s. 1419-1431Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We utilize transient techniques to directly compare the operation of polymer/fullerene, polymer/nanocrystal, and polymer/polymer bulk heterojunction solar cells. For all devices, poly(3-hexylthiophene) (P3HT) is used as the electron donating polymer, in combination with either the fullerene derivative phenyl-C(61)-butyric acid methyl ester (PCBM) in polymer/fullerene cells, CdSe nanoparticles in polymer/nanocrystal cells, or the polyfluorene copolymer poly((9,9-dioctylfluorene)-2,7-diyl-alt-[4,7-bis(3-hexylthien-5-yl)-2,1,3- benzothiadiazole]-2,2-diyl) (F8TBT) in polymer/polymer cells. Transient photocurrent and photovoltage measurements are used to probe the dynamics of charge-separated carriers, with vastly different dynamic behavior observed for polymer/fullerene, polymer/polymer, and polymer/nanocrystal devices on the microsecond to millisecond timescale. Furthermore, by employing transient photocurrent analysis with different applied voltages we are also able to probe the dynamics behavior of these cells from short circuit to open circuit. P3HT/F8TBT and P3HT/CdSe devices are characterized by poor charge extraction of the long-lived carriers attributed to charge trapping. P3HT/PCBM devices, in contrast, show relatively trap-free operation with the variation in the photocurrent decay kinetics with applied bias at low intensity, consistent with the drift of free charges under a uniform electric field. Under solar conditions at the maximum power point, we see direct evidence of bimolecular recombination in the P3HT/PCBM device competing with charge extraction. Transient photovoltage measurements reveal that, at open circuit, photogenerated charges have similar lifetimes in all device types, and hence, the extraction of these long-lived charges is a limiting process in polymer/nanocrystal and polymer/polymer devices.

  • 42.
    Liang, Xiaoyong
    et al.
    Zhejiang University, Peoples R China .
    Yi, Qing
    Zhejiang University, Peoples R China .
    Bai, Sai
    Zhejiang University, Peoples R China .
    Dai, Xingliang
    Zhejiang University, Peoples R China .
    Wang, Xin
    Zhejiang University, Peoples R China .
    Ye, Zhizhen
    Zhejiang University, Peoples R China .
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Zhang, Fengling
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Sun, Baoquan
    Soochow University, Peoples R China .
    Jin, Yizheng
    Zhejiang University, Peoples R China Zhejiang University, Peoples R China .
    Synthesis of Unstable Colloidal Inorganic Nanocrystals through the Introduction of a Protecting Ligand2014Ingår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 14, nr 6, s. 3117-3123Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We demonstrate a facile and general strategy based on ligand protection for the synthesis of unstable colloidal nanocrystals by using the synthesis of pure p-type NiO nanocrystals as an example. We find that the introduction of lithium stearate, which is stable in the reaction system and capable of binding to the surface of NiO oxide nanocrystals, can effectively suppress the reactivity of NiO nanocrystals and thus prevent their in situ reduction into Ni. The resulting p-type NiO nanocrystals, a highly demanded hole-transporting and electron-blocking material, are applied to the fabrication of organic solar cells and polymer light-emitting diodes, demonstrating their great potential as an interfacial layer for low-cost and large-area, solution-processed optoelectronic devices.

  • 43.
    Lim, Eunhee
    et al.
    University of Cambridge, England; Korea Institute Ind Technology KITECH, South Korea.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Schwartz, Erik
    Radboud University of Nijmegen, Netherlands.
    Cornelissen, Jeroen J. L. M.
    Radboud University of Nijmegen, Netherlands.
    Nolte, Roeland J. M.
    Radboud University of Nijmegen, Netherlands.
    Rowan, Alan E.
    Radboud University of Nijmegen, Netherlands.
    Greenham, Neil C.
    University of Cambridge, England.
    Do, Lee-Mi
    Elect and Telecommun Research Institute ETRI, South Korea.
    Carbazole Functionalized Isocyanide Brushes in Heterojunction Photovoltaic Devices2012Ingår i: Journal of Nanoscience and Nanotechnology, ISSN 1533-4880, E-ISSN 1533-4899, Vol. 12, nr 1, s. 503-507Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, carbazole-containing polyisocyanide (PIACz) brushes were used for photovoltaic devices. A photovoltaic device was fabricated on top of the brushes by spin-coating a suitable acceptor and evaporating an Al cathode. Devices with a poly(N-vinylcarbazole) (PVK) bulk polymer were also prepared for comparison. Interestingly, the brushes showed better photovoltaic characteristics as compared to the blended PVK system. This is attributed to the specific morphologies of the polyisocyanide brushes, which provide a large interfacial area between the donor and acceptor for efficient photogeneration. It was found that the device performance varied according to the molecular size of the incorporated acceptors.

  • 44.
    Liu, J. -M.
    et al.
    Nanjing University, Peoples R China; Chinese Academic Science, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Yuan, G. L.
    Nanjing University, Peoples R China; Chinese Academic Science, Peoples R China.
    Wang, Y.
    Nanjing University, Peoples R China; Chinese Academic Science, Peoples R China.
    Zeng, M.
    Nanjing University, Peoples R China; Chinese Academic Science, Peoples R China.
    Wan, J. G.
    Nanjing University, Peoples R China; Chinese Academic Science, Peoples R China.
    Ferroelectric and magnetoelectric behaviors of multiferroic BiFeO3 and piezoelectric-magnetostrictive composites2008Ingår i: Journal of Electroceramics, ISSN 1385-3449, E-ISSN 1573-8663, Vol. 21, nr 1-4, s. 78-84Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper we overview our recent work on ferroelectric and magnetoelectric coupling behaviors of multiferroic doped BiFeO3 (BFO) and piezoelectric-magnetostrictive composites. Using rapid liquid sintering method we prepare single-phase BFO ceramics of excellent ferroelectric property. The BFO thin films on Pt-coated silicon wafers by pulsed laser deposition show large remnant polarization but serious ferroelectric switching fatigue. A series of piezoelectric-magnetostrictive composite structures in bulk and thin film forms are prepared and giant magnetoelectric coupling effect of them is observed. The experimentally measured results are confirmed by numerical modeling based on piezoelectric and magnetostrictive constitution equations.

  • 45.
    Lu, C. L.
    et al.
    Nanjing University, Peoples R China.
    Dong, S.
    Nanjing University, Peoples R China.
    Wang, K. F.
    Nanjing University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Li, P. L.
    Nanjing University, Peoples R China.
    Lv, L. Y.
    Nanjing University, Peoples R China.
    Liu, J.-M.
    Nanjing University, Peoples R China.
    Charge-order breaking and ferromagnetism in La0.4Ca0.6MnO3 nanoparticles2007Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 91, nr 3, s. 032502-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    La0.4Ca0.6MnO3 nanoparticles of grain size as small as similar to 20 nm are prepared and their magnetic behaviors are investigated in order to understand the size effect of the charge ordering in manganites. The highly stable charge-ordered state can be significantly suppressed upon reduction of the grain size down to nanometer scale, while the ferromagnetism is enhanced. The magnetic phase separation due to the competition between ferromagnetic state and charge-ordered state as well as the surface spin disordering is responsible for the spin-glass-like state at low temperature. (C) 2007 American Institute of Physics.

  • 46.
    Peng, Zuosheng
    et al.
    Jinan University, Peoples R China.
    Xia, Yuxin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan. Jinan University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten. S China University of Technology, Peoples R China.
    Xiong, Kang
    Jinan University, Peoples R China.
    Hu, Zhanhao
    S China University of Technology, Peoples R China.
    Ian James, David
    Chalmers, Sweden.
    Chen, Junwu
    S China University of Technology, Peoples R China.
    Wang, Ergang
    Chalmers, Sweden.
    Hou, Lintao
    Jinan University, Peoples R China.
    A dual ternary system for highly efficient ITO-free inverted polymer solar cells2015Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 3, nr 36, s. 18365-18371Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, it has been found that a very fine nanostructure can be realized by mixing 1-chloronaphthalene (CN) - a high-boiling solvent into a binary chlorobenzene (CB) : 1,8-diiodooctane (DIO) solvent mixture to form a ternary solvent system. An improvement in energy level alignment is also obtained by doping ICBA into a binary PTB7 : PCBM[70] blend, whereby the ternary solute system provides a new pathway for charge transfer from PTB7 to the PCBM[ 70] : ICBA alloy. This is confirmed by imaging the surface morphology of the active layer using AFM and TEM, monitoring the transient film formation process and measuring the charge transfer states with Fourier transform photocurrent spectroscopy. An encouraging PCE of 7.65% is achieved from the dual ternary system, which is the highest value ever reported for an ITO-free inverted polymer solar cell with a PEDOT:PSS layer as the top semitransparent electrode - a system which is compatible with low-cost large-area roll-to-roll manufacturing.

  • 47.
    Qiu, X. Y.
    et al.
    Nanjing University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Liu, H. W.
    Nanjing University, Peoples R China.
    Zhu, J. S.
    Nanjing University, Peoples R China.
    Liu, J. -M.
    Nanjing University, Peoples R China.
    Phase separation enhanced interfacial reactions in complex high-k dielectric films2006Ingår i: Integrated Ferroelectrics, ISSN 1058-4587, E-ISSN 1607-8489, Vol. 86, nr 1, s. 13-19Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Amorphous CaZrOx, ZrAlxSiyOz and HfAlOx complex high-k dielectric films are deposited by pulsed laser deposition, and their microstructural characteristics and interfacial reactions between deposited films and Si substrates during high temperature annealing processes are investigated by X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. An essential finding is that nano-scale phase separation appears to be a common phenomenon for these amorphous films. The nonstoichiometric ZrOx or HfOx clusters precipitating from the amorphous matrix either react with silicon on the interface to form silicate or silicide interfacial layer, or nucleate and grow into nanosized crystals embedded in the outer layer of the dielectric films, which degrades the electrical performances of films.

  • 48.
    Qiu, X. Y.
    et al.
    Nanjing University, Peoples R China.
    Liu, H. W.
    Nanjing University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Liu, J. -M.
    Nanjing University, Peoples R China.
    Thermal stability and interfacial properties of ZrAlxSiyOz films prepared by pulse-laser deposition2006Ingår i: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 100, nr 7, s. 074109-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The thermal stability and interfacial properties of amorphous ZrAlxSiyOz films prepared under high vacuum conditions by pulse-laser deposition are investigated. A high anticrystallization temperature of 916 degrees C is identified by x-ray diffraction and differential scanning calorimeter. However, it is found that ZrOx clusters may precipitate from amorphous film matrix at a temperature as low as 700 degrees C, which subsequently react with Si substrate to form amorphous Zr-silicide interfacial layer. Due to the conductivity and good interfacial morphology of amorphous Zr-silicide interfacial layer, the Pt/ZrAlxSiyOz/IL/Si stack gate structures exhibit good electrical properties such as small equivalent oxide thickness of 0.9 nm, flatband voltage of 0.43 V, and low leakage density of 64 mA/cm(2) at 1 V gate voltage. (c) 2006 American Institute of Physics.

  • 49.
    Qiu, X. Y.
    et al.
    Nanjing University, Peoples R China.
    Liu, Q. M.
    Nanjing University, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan.
    Lu, L. Y.
    Nanjing University, Peoples R China.
    Liu, J. -M.
    Nanjing University, Peoples R China.
    Room-temperature weak ferromagnetism of amorphous HfAlOx thin films deposited by pulsed laser deposition2006Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 89, nr 24, s. 242504-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The room-temperature weak ferromagnetism of amorphous HfAlOx thin films deposited by pulsed laser deposition on various substrates in oxygen-defective ambient is demonstrated. The magnetization is independent of film thickness, but depends on substrates and deposition temperatures. A magnetic moment of similar to 0.26 mu(B) per HfAlOx f.u. is recorded for HfAlOx films deposited under optimized conditions [deposited at 600 degrees C on (001) sapphire in high vacuum]. It is argued that interfacial defects are one of the possible sources of the weak ferromagnetism. (c) 2006 American Institute of Physics.

  • 50.
    Schwarze, Martin
    et al.
    Technical University of Dresden, Germany.
    Tress, Wolfgang
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska högskolan. Swiss Federal Institute Technology EPFL, Switzerland.
    Beyer, Beatrice
    Fraunhofer Institute Electron Beam Plasma Technology and CO, Germany.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Scholz, Reinhard
    Technical University of Dresden, Germany; Technical University of Dresden, Germany.
    Poelking, Carl
    Max Planck Institute Polymer Research, Germany.
    Ortstein, Katrin
    Technical University of Dresden, Germany.
    Guenther, Alrun A.
    Technical University of Dresden, Germany.
    Kasemann, Daniel
    Technical University of Dresden, Germany.
    Andrienko, Denis
    Max Planck Institute Polymer Research, Germany.
    Leo, Karl
    Technical University of Dresden, Germany.
    Band structure engineering in organic semiconductors2016Ingår i: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 352, nr 6292, s. 1446-1449Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A key breakthrough in modern electronics was the introduction of band structure engineering, the design of almost arbitrary electronic potential structures by alloying different semiconductors to continuously tune the band gap and band-edge energies. Implementation of this approach in organic semiconductors has been hindered by strong localization of the electronic states in these materials. We show that the influence of so far largely ignored long-range Coulomb interactions provides a workaround. Photoelectron spectroscopy confirms that the ionization energies of crystalline organic semiconductors can be continuously tuned over a wide range by blending them with their halogenated derivatives. Correspondingly, the photovoltaic gap and open-circuit voltage of organic solar cells can be continuously tuned by the blending ratio of these donors.

12 1 - 50 av 70
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf