Polymer(Korea) (폴리머)

The Polymer Society of Korea (한국고분자학회)
권호 표지
DOI QR코드

DOI QR Code

Synthesis and Photovoltaic Properties of a Low Band Gap Polymer for Organic Solar Cell

유기태양전지를 위한 작은 밴드갭 고분자의 합성과 광전특성

  • Woo, Yong-Ho (Department of Polymer Science and Engineering, Kumoh National Institute of Technology) ;
  • Lee, Hyo-Sang (Korea Institute of Science and Technology) ;
  • Park, Sungnam (Green School, Korea University) ;
  • Choi, E-Joon (Department of Polymer Science and Engineering, Kumoh National Institute of Technology) ;
  • Kim, BongSoo (Korea Institute of Science and Technology)
  • 우용호 (금오공과대학교 고분자공학과) ;
  • 이효상 (한국과학기술연구원) ;
  • 박성남 (고려대학교 그린스쿨) ;
  • 최이준 (금오공과대학교 고분자공학과) ;
  • 김봉수 (한국과학기술연구원)
  • Received : 2013.05.24
  • Accepted : 2013.07.25
  • Published : 2015.01.25
Download PDF
⟨ Previous Next ⟩

Abstract

We synthesized a low band gap alternating copolymer containing electron-rich units (i.e. dithienosiloles and benzodithiophenes) and electron-deficient units (i.e. difluorobenzothiadiazoles) for high performance organic solar cells. The polymer was prepared by the Stille coupling reaction and characterized using $^1H$ NMR, GPC, TGA, UV-visible absorption spectroscopy, and cyclic voltammetry. Solar cells were fabricated in a structure of ITO/PEDOT:PSS/polymer: $PC_{70}BM/Al$ with five different blending ratios of polymer and $PC_{70}BM$ (1:1.5, 1:2, 1:3, 1:3.5 and 1:4 by weight ratio). The best efficiency was achieved from the 1:3 ratio of polymer and $PC_{70}BM$ in the photoactive layer, and TEM revealed that there is an optimal nanoscale phase separation between polymer and $PC_{70}BM$ in the 1:3 ratio blend film.

본 연구에서는 전자가 풍부한 구조단위(dithienosilole 및 benzodithiophene)와 전자가 부족한 구조단위(difluorobenzothiadiazole)를 주사슬에 교대로 갖는 작은 밴드갭 공중합체를 Stille 짝지움 반응을 이용하여 합성하였다. $^1H$ NMR을 통하여 각 단계별 화합물과 고분자의 구조를 확인하였다. GPC, TGA, UV-vis 분광분석기 및 cyclic voltammetry를 이용하여 합성한 고분자의 특성을 조사하였다. 합성한 공액고분자와 $PC_{70}BM$을 1:1.5, 1:2, 1:3, 1:3.5 및 1:4의 중량비로 혼합하여 ITO/PEDOT:PSS/polymer:$PC_{70}BM/Al$의 구조로 유기태양전지 소자를 제작하여 그 광전특성을 조사하였다. 고분자:$PC_{70}BM$의 혼합비율이 1:3에서 최고 1.0%의 광전변환효율이 달성되었다. TEM 실험을 통하여 1:3 혼합비율에서 유기태양전지에 가장 적합한 나노규모로 상분리가 일어났으며, 다른 혼합비율에서는 고분자와 $PC_{70}BM$의 뭉침현상에 기인하여 태양전지 특성이 낮아졌다.

Keywords

Acknowledgement

Grant : 화학인재양성사업단

References

  1. F. C. Krebs, Sol. Energy Mater. Sol. Cells, 93, 394 (2009). https://doi.org/10.1016/j.solmat.2008.10.004
  2. S. Gnes, H. Neugebauer, and N. S. Sariciftci, Chem. Rev., 107, 1324 (2007). https://doi.org/10.1021/cr050149z
  3. A. C. Arias, J. D. MacKenzie, I. McCulloch, J. Rivnay, and A. Salleo, Chem. Rev., 110, 3 (2010). https://doi.org/10.1021/cr900150b
  4. C. J. Brabec, N. S. Sariciftci, and J. C. Hummelen, Adv. Funct. Mater., 11, 15 (2001). https://doi.org/10.1002/1616-3028(200102)11:1<15::AID-ADFM15>3.0.CO;2-A
  5. F. C. Krebs, T. Tromholt, and M. Jorgensen, Nanoscale, 2, 873 (2010). https://doi.org/10.1039/b9nr00430k
  6. E. Bundgaard, O. Hagemann, M. Manceau, M. Jorgensen, and F. C. Krebs, Macromolecules 43, 8115 (2010). https://doi.org/10.1021/ma1015903
  7. J. You, L. Dou, K. Yoshimura, T. Kato, K. Ohya, T. Moriarty, K. Emery, C.-C. Chen, J. Gao, G. Li, and Y. Yang, Nat. Commun., 4:1446 doi: 10.1038/ncomms2411 (2013).
  8. M. C. Scharber, M. Koppe, J. Gao, F. Cordella, M. A. Loi, P. Denk, M. Morana, H.-J. Egelhaaf, K. Forberich, G. Dennler, R. Gaudiana, D. Waller, Z. Zhu, X. Shi, and C. J. Brabec, Adv. Mater., 22, 367 (2010). https://doi.org/10.1002/adma.200900529
  9. C. M. Amb, S. Chen, K. R. Graham, J. Subbiah, C. E. Small, F. So, and J. R. Reynolds, J. Am. Chem. Soc., 133, 10062 (2011). https://doi.org/10.1021/ja204056m
  10. H.-Y. Chen, J. Hou, A. E. Hayden, H. Yang, K. N. Houk, and Y. Yang, Adv. Mater., 22, 371 (2010). https://doi.org/10.1002/adma.200902469
  11. H. Zhou, L. Yang, A. C. Stuart, S. C. Price, S. Liu, and W. You, Angew. Chem. Int. Ed., 50, 2995 (2011). https://doi.org/10.1002/anie.201005451
  12. Z. Li, J. Lu, S.-C. Tse, J. Zhou, X. Du, Y. Tao, and J. Ding, J. Mater. Chem., 21, 3226 (2011). https://doi.org/10.1039/c0jm04166a
  13. B. C. Schroeder, Z. Huang, R. S. Ashraf, J. Smith, P. D'Angelo, S. E. Watkins, T. D. Anthopoulos, J. R. Durrant, and I. McCulloch, Adv. Funct. Mater., 22, 1663 (2012). https://doi.org/10.1002/adfm.201102941
  14. Y. Huang, X. Guo, F. Liu, L. Huo, Y. Chen, T. P. Russell, C. C. Han, Y. Li, and J. Hou, Adv. Mater., 24, 3383 (2012). https://doi.org/10.1002/adma.201200995
  15. X. Wang, Y. Sun, S. Chen, X. Guo, M. Zhang, X. Li, Y. Li, and H. Wang, Macromolecules, 45, 1208 (2012). https://doi.org/10.1021/ma202656b
  16. R. C. Coffin, J. Peet, J. Rogers, and G. C. Bazan, Nat. Chem., 1, 657 (2009). https://doi.org/10.1038/nchem.403
  17. J. C. Bijleveld, A. P. Zoombelt, S. G. J. Mathijssen, M. M. Wienk, M.Turbiez, D. M. de Leeuw, and R. A. J. Janssen, J. Am. Chem. Soc., 131, 16616 (2009). https://doi.org/10.1021/ja907506r
  18. S. H. Park, A. Roy, S. Beaupr, S. Cho, N. Coates, J. S. Moon, D. Moses, M. Leclerc, K. Lee, and A. J. Heeger, Nat. Photonics, 3, 297 (2009). https://doi.org/10.1038/nphoton.2009.69