A Study on Improving Electrical Conductivity for Conducting Polymers and their Applications to Transparent Electrodes

전도성 고분자의 전기전도도 향상 연구 및 이를 이용한 투명전극 응용

  • Im, Soeun (Department of Chemical and Biomolecular Engineering, Yonsei University) ;
  • Kim, Soyeon (Department of Chemical and Biomolecular Engineering, Yonsei University) ;
  • Kim, Seyul (Department of Chemical and Biomolecular Engineering, Yonsei University) ;
  • Kim, Felix Sunjoo (Department of Chemical Engineering and Materials Science, Chung-Ang University) ;
  • Kim, Jung Hyun (Department of Chemical and Biomolecular Engineering, Yonsei University)
  • 임소은 (연세대학교 화공생명공학과) ;
  • 김소연 (연세대학교 화공생명공학과) ;
  • 김세열 (연세대학교 화공생명공학과) ;
  • 김선주 (중앙대학교 화학신소재공학부) ;
  • 김중현 (연세대학교 화공생명공학과)
  • Received : 2015.09.30
  • Accepted : 2015.11.15
  • Published : 2015.12.10


As the need for next-generation flexible electronics grows, novel materials and technologies that can replace conventional indium tin oxide (ITO) for transparent electrodes have been of great interest. Among them, a conducting polymer, especially poly(3,4-ethylenedioxythiophene) : poly(styrene sulfonate) (PEDOT : PSS) is one of the most promising candidates because it is mechanically flexible, inexpensive, and capable of being processed in solution. Currently, there are a lot of research efforts on enhancing its electrical conductivity to the level of ITO or metal electrodes through chemical and/or physical processing. In this review article, we present various additives and pre-/post-deposition processing methods for improving the electrical conductivity of PEDOT : PSS. Some of representative reports are also introduced, which demonstrated the use of conductivity-enhanced PEDOT : PSS as transparent electrodes in electronics and energy conversion.


conducting polymer;poly(3,4-ethylenedioxythiophene) : poly(styrene sulfonate) (PEDOT : PSS);transparent electrode


Supported by : National Research Foundation of Korea (NRF)


  1. H. Sirringhaus, T. Kawase, R. Friend, T. Shimoda, M. Inbasekaran, W. Wu, and E. Woo, High-resolution inkjet printing of all-polymer transistor circuits, Science, 290, 2123-2126 (2000).
  2. M.-W. Lee, M.-Y. Lee, J.-C. Choi, J.-S. Park, and C.-K. Song, Fine patterning of glycerol-doped PEDOT : PSS on hydrophobic PVP dielectric with ink jet for source and drain electrode of OTFTs, Organic Electronics, 11, 854-859 (2010).
  3. M. H. Chung, Large scale patterning of flexible PEDOT : PSS electrode using photolithography process, Graduate School, Yonsei University, Seoul (2015).
  4. S.-F. Tseng, W.-T. Hsiao, K.-C. Huang, and D. Chiang, Electrode patterning on PEDOT : PSS thin films by pulsed ultraviolet laser for touch panel screens, Applied Physics A, 112, 41-47 (2013).
  5. J.-S. Yeo, J.-M. Yun, D.-Y. Kim, S.-S. Kim, and S.-I. Na, Successive solvent-treated PEDOT : PSS electrodes for flexible ITO-free organic photovoltaics, Solar Energy Materials and Solar Cells, 114, 104-109 (2013).
  6. Y. Xia and J. Ouyang, Significant conductivity enhancement of conductive poly (3, 4-ethylenedioxythiophene): poly (styrenesulfonate) films through a treatment with organic carboxylic acids and inorganic acids, ACS applied materials & interfaces, 2, 474-483 (2010).
  7. Y. Xia, K. Sun, and J. Ouyang, Solution‐Processed Metallic Conducting Polymer Films as Transparent Electrode of Optoelectronic Devices, Advanced Materials, 24, 2436-2440 (2012).
  8. J. Ouyang, Solution-processed PEDOT : PSS films with conductivities as indium tin oxide through a treatment with mild and weak organic acids, ACS Appl. Mater. Interfaces, 5, 13082-13088 (2013).
  9. N. Kim, S. Kee, S. H. Lee, B. H. Lee, Y. H. Kahng, Y. R. Jo, B. J. Kim, and K. Lee, Highly Conductive PEDOT : PSS Nanofibrils Induced by Solution‐Processed Crystallization, Advanced Materials, 26, 2268-2272 (2014).
  10. Y. Y. Lee, J. H. Lee, J. Y. Cho, N. R. Kim, D. H. Nam, I. S. Choi, K. T. Nam, and Y. C. Joo, Stretching‐Induced Growth of PEDOT‐Rich Cores: A New Mechanism for Strain Dependent Resistivity Change in PEDOT : PSS Films, Advanced Functional Materials, 23, 4020-4027 (2013).
  11. J. J. Lee, S. H. Lee, F. S. Kim, H. H. Choi, and J. H. Kim, Simultaneous enhancement of the efficiency and stability of organic solar cells using PEDOT : PSS grafted with a PEGME buffer layer. Organic Electronics, 26, 191-199 (2015).
  12. M. R. Choi, et al. Soluble Self-Doped Conducting Polymer Compositions with Tunable Work Function as Hole Injection/Extraction Layers in Organic Optoelectronics, Angewandte Chemie, 50, 6274-6277 (2011).
  13. Y. H. Kim, et al. Multicolored Organic/Inorganic Hybrid Perovskite Light Emitting Diodes, Advanced Materials, 27, 1248-1254 (2015).
  14. T. W. Lee, Y. Chung, O. Kwon, and J. J. Park, Self-Organized Gradient Hole Injection to Improve the Performance of Polymer Electroluminescent Devices, Advanced Functional Materials, 17, 390-396 (2007).
  15. T.-H. Han, et al. Extremely efficient flexible organic light-emitting diodes with modified graphene anode, Nature Photonics, 6, 105-110 (2012).
  16. K. G. Lim, et al. Boosting the Power Conversion Efficiency of Perovskite Solar Cells Using Self-Organized Polymeric Hole Extraction Layers with High Work Function, Advanced Materials, 26, 6461-6466 (2014).
  17. Y. H. Kim, C. Sachse, M. L. Machala, C. May, L. Müller Meskamp, and K. Leo, Highly conductive PEDOT : PSS electrode with optimized solvent and thermal post-treatment for ITO-free organic solar cells, Advanced Functional Materials, 21, 1076-1081 (2011).
  18. J. Ha, J. Park, J. Ha, D. Kim, S. Chung, C. Lee, and Y. Hong, Selectively modulated inkjet printing of highly conductive and transparent foldable polymer electrodes for flexible polymer light-emitting diode applications, Organic Electronics, 19, 147-156 (2015).
  19. O. Inganas, Organic photovoltaics: avoiding indium, Nature Photonics, 5, 201-202 (2011).
  20. J. E. Yoo, K. S. Lee, A. Garcia, J. Tarver, E. D. Gomez, K. Baldwin, Y. Sun, H. Meng, T.-Q. Nguyen, and Y.-L. Loo, Directly patternable, highly conducting polymers for broad applications in organic electronics, Proceedings of the National Academy of Sciences, 107, 5712-5717 (2010).
  21. R. Po, C. Carbonera, A. Bernardi, F. Tinti, and N. Camaioni, Polymer-and carbon-based electrodes for polymer solar cells: toward low-cost, continuous fabrication over large area, Solar Energy Materials and Solar Cells, 100, 97-114 (2012).
  22. K. S. Kim, Y. Zhao, H. Jang, S. Y. Lee, J. M. Kim, K. S. Kim, J.-H. Ahn, P. Kim, J.-Y. Choi, and B. H. Hong, Large-scale pattern growth of graphene films for stretchable transparent electrodes, Nature, 457, 706-710 (2009).
  23. L. H. Jimison, A. Hama, X. Strakosas, V. Armel, D. Khodagholy, E. Ismailova, G. G. Malliaras, B. Winther-Jensen, R. M. Owens, PEDOT: TOS with PEG: a biofunctional surface with improved electronic characteristics, Journal of Materials Chemistry, 22, 19498-19505 (2012).
  24. J. Kim, J. Jung, D. Lee, and J. Joo, Enhancement of electrical conductivity of poly (3, 4-ethylenedioxythiophene)/poly (4-styrenesulfonate) by a change of solvents, Synthetic Metals, 126, 311-316 (2002).
  25. S.-I. Na, G. Wang, S.-S. Kim, T.-W. Kim, S.-H. Oh, B.-K. Yu, T. Lee, and D.-Y. Kim, Evolution of nanomorphology and anisotropic conductivity in solvent-modified PEDOT : PSS films for polymeric anodes of polymer solar cells, Journal of Materials Chemistry, 19, 9045-9053 (2009).
  26. C. Badre, L. Marquant, A. M. Alsayed, and L. A. Hough, Highly conductive poly(3, 4‐ethylenedioxythiophene) : poly(styrenesulfonate) films using 1-ethyl-3-methylimidazolium tetracyanoborate ionic liquid, Advanced Functional Materials, 22, 2723-2727 (2012).
  27. F. Atabaki, M. H. Yousefi, A. Abdolmaleki, and M. Kalvandi, poly(3, 4-ethylenedioxythiophene) : poly(Styrenesulfonic acid) (PEDOT : PSS) conductivity enhancement through addition of imidazolium- ionic liquid derivatives, Polymer-Plastics Technology and Engineering (2014).
  28. B. Fan, X. Mei, and J. Ouyang, Significant conductivity enhancement of conductive poly(3, 4-ethylenedioxythiophene) : poly(styrenesulfonate) films by adding anionic surfactants into polymer solution, Macromolecules, 41, 5971-5973 (2008).
  29. M. Vosgueritchian, D. J. Lipomi, and Z. Bao, Highly conductive and transparent PEDOT : PSS films with a fluorosurfactant for stretchable and flexible transparent electrodes, Advanced functional materials, 22, 421-428 (2012).
  30. F. Yan, E. P. Parrott, B. S.-Y. Ung, and E. Pickwell-MacPherson, Solvent Doping of PEDOT/PSS: Effect on Terahertz Optoelectronic Properties and Utilization in Terahertz Devices, The Journal of Physical Chemistry C, 119, 6813-6818 (2015).
  31. D. Alemu, H.-Y. Wei, K.-C. Ho, and C.-W. Chu, Highly conductive PEDOT : PSS electrode by simple film treatment with methanol for ITO-free polymer solar cells, Energy & environmental science, 5, 9662-9671 (2012).

Cited by

  1. Oxidation of copper nanowire based transparent electrodes in ambient conditions and their stabilization by encapsulation: application to transparent film heaters vol.29, pp.8, 2018,