Article
  • Solvent Effects on the Charge Transport Behavior in Poly(3,4-ethylenedioxythiophene) Synthesized with Iron(III)-p-toluenesulfonate
  • Park CM, Kim TY, Kim WJ, Kim YS, Suh KS
  • Iron(III)-p-toluenesulfonate로 합성된 Poly(3,4-ethylenedioxythiophene)의 전하전달현상에 미치는 유기용매의 영향
  • 박창모, 김태영, 김원중, 김윤상, 서광석
Abstract
The effects of organic solvent on the charge transport behavior of poly(3,4-ethylenedioxythiophene)/p-toluenesulfonate(PEDOT-OTs) are investigated. The use of different organic solvents during the oxidative chemical polymerization of 3,4-ethylenedioxythiophene(EDOT) with Iron(III)-tosylate can greatly vary the DC conductivity of PEDOT-OTs along with molecular structure and doping concentration. For example, PEDOT-OTs prepared from methanol shows the conductivity of 19.5 S/cm, which is an increase by a factor of 108 compared to PEDOT-OTs prepared from acetone. From the X-ray diffraction (XRD) experiments, it was found that PEDOT-OTs with ketone is amorphous state, while PEDOT-OTs with alcoholic solvent shows the better defined crystalline structure in which the charge transport along and between the PEDOT chains are promoted. Chemical analysis employing X-ray photoelectron spectroscopy (XPS) revealed that the doping concentration of PEDOT-OTs with alcoholic solvent is much higher than that of PEDOT-OTs with ketones. It is proposed that the interactions between the organic solvent and doping anion can cause the variation in doping concentration and, therefore, result in the PEDOT-OTs of different conductivities and chain structures.

Iron(III)-p-toluenesulfonate를 개시제로 한 3,4-ethylenedioxythiophene(EDOT)의 중합과정시 여러 가지 유기용매를 첨가했을 때 poly(3,4-ethylenedioxythiophene)(PEDOT)의 전하이동특성이 어떻게 변하는지에 대해 연구하였다. 첨가한 유기용매의 종류는 MeOH, EtOH 등의 알콜류와 Acetone, MEK 등의 케톤류였으며, 직류 전기전도도 측정시 280 K에서 전도도는 MeOH를 첨가한 시료가 19.5 S/cm로 가장 높았으며, MEK를 첨가한 시료는 2.2X10-9 S/cm로 각기 다른 전도도를 나타내었다. 유기용매 첨가에 따른 전기전도도의 변화를 설명하기 위해 X-ray diffraction(XRD)를 통한 PEDOT의 구조적 변화를 관찰하였으며, 알콜류를 첨가했을 경우 결정화도가 증가하는 반면, 케톤류의 유기용매를 첨가했을 경우에는 무정형 구조를 가지는 것을 관찰하였다. 또한 X-ray photoelectron spectroscopy(XPS)를 이용하여 S(2p) 피크를 분석한 결과 케톤류를 첨가한 시료의 경우 다른 시료에 비해 도핑레벨이 매우 낮음을 관찰하였다. 이는 유기용매와 PEDOT의 상대이온인 p-toluenesulfonate와의 상호작용으로 인한 것으로 중합시 유기용매의 첨가에 따라 PEDOT의 도핑효율 및 구조가 변화하고 결과적으로 전기전도도갑 ㅕㄴ화하는 것을 확인하였다.

Keywords: charge transport; DC conductivity; poly(3,4-ethylenedioxythiophene) (PEDOT); iron(III)-p-toluenesulfonate (Fe(OTs)3); X-ray photoelectron spectroscopy (XPS).

References
  • 1. Groenendaal L, Jonas F, Freitag D, Pielartzik H, Reynolds JR, Adv. Mater., 12, 481 (2000)
  •  
  • 2. Skotheim TA, Elsenbaumer RL, Reynolds JRHandbook of Conducting Polymers, Marcel Dekker, New York (1998)
  •  
  • 3. Leclerc M, Daoust G, Synth. Met., 41-43, 529 (1991)
  •  
  • 4. Jonas F, Heywang G, Schmidtberg W, Heinze J, Dietrich MU.S.Patent 5035926 (1991)
  •  
  • 5. Jonas F, Krafft W, Muys B, Macromol. Symp., 100, 169 (1995)
  •  
  • 6. Jonas F, Heywang G, Electrochim. Acta, 39(8-9), 1345 (1994)
  •  
  • 7. deLeeuw DM, Kraakman PA, Bongaerts PFG, Mutsaers CMJ, Klaassen DBM, Synth. Met., 66, 263 (1994)
  •  
  • 8. Pettersson LAA, Johansson T, Carlsson F, Arwin H, Inganas O, Synth. Met., 101, 198 (1999)
  •  
  • 9. MacDiarmid AG, Epstein AJ, Synth. Met., 65, 103 (1994)
  •  
  • 10. Kim JY, Jung JH, Lee DE, Joo J, Synth. Met., 126, 311 (2002)
  •  
  • 11. Mott NF, Davis EAElectronic Processes in Non-crystalline Materials, Clarendon press, Oxford (1979)
  •  
  • 12. Campos M, Bello B, J. Phys. D-Appl. Phys., 30, 1531 (1997)
  •  
  • 13. Menon R, Yoon CO, Moses D, Heeger AJ, Cao Y, Phys. Rev. B, 48, 17685 (1993)
  •  
  • 14. Aasmundveit KE, Samuelsen EJ, Inganas O, Petterson LAA, Johansson T, Ferrer S, Synth. Met., 113, 93 (2000)
  •  
  • 15. Crispin X, Marciniak S, Osikowicz W, Zotti G, Van der Gon AWD, Louwet F, Fahlman M, Groenendaal L, De Schryver F, Salaneck WR, J. Polym. Sci. B: Polym. Phys., 41(21), 2561 (2003)
  •  
  • 16. Kaiser AB, Rep. Prog. Phys., 64, 1 (1987)
  •  
  • 17. Kivelson S, Heeger AJ, Synth. Met., 17, 183 (1987)
  •  
  • 18. Zotti G, Zecchin S, Schiavon G, Louwet F, Groenendaal L, Crispin X, Osikowicz W, Salaneck W, Fahlman M, Macromolecules, 36(9), 3337 (2003)
  •  
  • Polymer(Korea) 폴리머
  • Frequency : Bimonthly(odd)
    ISSN 0379-153X(Print)
    ISSN 2234-8077(Online)
    Abbr. Polym. Korea
  • 2022 Impact Factor : 0.4
  • Indexed in SCIE

This Article

  • 2005; 29(4): 363-368

    Published online Jul 25, 2005

  • Received on Feb 24, 2005
  • Accepted on May 23, 2005