• 제목/요약/키워드: Regioregularity

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Magnetic and Magneto-Optical Properties of Conjugated Polymers: A New Frontier

  • Gangopandhyay, Palash;Foerier, Stijn;Vangheluwe, M.;Koeckelberghs, Guy;Verbiest, Thiery;Persoons, Andr
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.23-24
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    • 2006
  • Magnetic and magneto-optical properties of regioregular (>99%) poly(3-dodecylthiopenes are investigated. Faraday rotation of spin-coated films show extremely large Verdet constants, falling strongly with decreasing regioregularity. EPR spectroscopy at room temperature shows the presence of about 1 spin/190 monomers, indicative of delocalisation beyond a single polymer chain. SQUID measurements on the polymer give an effective magnetic moment of about 48900 mB, corrsponding to a S-value of 25.000. The Weiss-constant is 1.33 K indicating ferromagnetic coupling. Our experimental results show that organic polymer magnets can be prepared. Large MO effects allow the use of these materials in all-organic MO-sensors and devices.

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Effects of Carrier Mobility on Photocurrent Generation in $TiO_2/Poly$(alkylthiophene) Photovoltaic Devices

  • Song, Mi-Yeon;Kim, Kang-Jin;Kim, Dong-Young
    • Macromolecular Research
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    • 제14권6호
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    • pp.630-633
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    • 2006
  • In heterojunction photovoltaic devices of $ITO/TiO_2/poly$(3-alkylthiophene)/Au, the photo current was characterized at different temperatures for different alkyl chain lengths and regioregularities: regiorandom, regioregular poly(3-hexylthiophene), and regioregular poly(3-dodecylthiophene). The regioregularity and alkyl chain length affected the photovoltaic characteristics due to differences in hole-carrier transportation. The drift charge mobilities of these devices were analyzed by the space-charge-limited current theory using the relation between the dark current and the bias voltage. The photocurrent in the devices based on poly(3-alkylthiophene)s decreased rapidly below the temperature at which the drift charge mobility was $10^{-5}\;cm^2/V{\cdot}s$.