Applied Physics A

, 125:819 | Cite as

Design of parallel-connected polymer tandem solar cells using efficient low bandgap PTB7-Th:PC71BM blend

  • Yue ZangEmail author
  • Qing Xin
  • Jun Lin
  • Jufeng Zhao
  • Guangmang Cui


Parallel-connected tandem cells adopting a highly efficient donor polymer, PTB7-Th, combined with acceptor fullerene PC71BM as the back sub-cell was introduced to further improve the performance of polymer solar cells. Design of the device architecture was investigated using modeling and simulation methods based on the transfer matrix formalism. To optimize the device structure, detailed analysis of the effect of active layer thickness, different device structure, and transparent Ag intermediated electrode on the short-circuit current density has been studied. It was found the long-wavelength absorption in the top-illuminated ITO-free back cell was significantly enhanced due to the resonant microcavity effect, leading to an efficient utilization of the incident light and increased photocurrent. Giving these advantages, the power conversion efficiency of the parallel homo-tandem cell was estimated to be ~ 11%, which was ~ 15% higher than that of a single cell of PTB7-Th. Moreover, the maximum achievable current density and the corresponding optimum active layer thickness of the sub-cells varied a little as the thickness of ultrathin Ag layer was changed, indicating that parallel connection architecture provided more freedom in the design and optimization for high-performance tandem solar cells.



This work is supported by the National Nature Science Foundation of China (NSFC) (Grant no. 61705054), Zhejiang Provincial Natural Science Foundation of China (Grant no. LQ17F050002 and LY17B060012), National Key Scientific Instrument and Equipment Development Projects of China (Grant no. 2016YFF0101908). This work is supported by Zhejiang Provincial Lab of Equipment Electronics.


  1. 1.
    G. Li, R. Zhu, Y. Yang, Polymer solar cells. Nat Photonics 6, 153–161 (2012)ADSCrossRefGoogle Scholar
  2. 2.
    W.Z. Cai, X. Gong, Y. Cao, Polymer solar cells: recent development and possible routes for improvement in the performance. Sol Energy Mater Sol Cells 94, 114–127 (2010)CrossRefGoogle Scholar
  3. 3.
    Y. Liang, Z. Xu, J. Xia, S.T. Tsai, Y. Wu, G. Li, C. Ray, L. Yu, For the bright future-bulk heterojunction polymer solar cells with power conversion efficiency of 7.4%. Adv Mater 22, 135 (2010)CrossRefGoogle Scholar
  4. 4.
    L. Ye, S. Zhang, L. Huo, M. Zhang, J. Hou, Molecular design toward highly efficient photovoltaic polymers based on two-dimensional conjugated benzodithiophene. Acc Chem Res 47, 1595–1603 (2014)CrossRefGoogle Scholar
  5. 5.
    X.G. Guo, N.J. Zhou, S.J. Lou, J. Smith, D.B. Tice, J.W. Hennek, R.P. Ortiz, J.T.L. Navarrete, S.Y. Li, J. Strzalka, L.X. Chen, R.P.H. Chang, A. Facchetti, T.J. Marks, Polymer solar cells with enhanced fill factors. Nat Photonics 7, 825–833 (2013)ADSCrossRefGoogle Scholar
  6. 6.
    Z. He, C. Zhong, S. Su, M. Xu, H. Wu, Y. Cao, Enhanced power-conversion efficiency in polymer solar cells using an inverted device structure. Nat Photonics 6, 591–595 (2012)ADSCrossRefGoogle Scholar
  7. 7.
    J. Kong, I.-W. Hwang, K. Lee, Top-down approach for nanophase reconstruction in bulk heterojunction solar cells. Adv Mater 26, 6275–6283 (2014)ADSCrossRefGoogle Scholar
  8. 8.
    Y. Liu, J. Zhao, Z. Li, C. Mu, W. Ma, H. Hu, K. Jiang, H. Lin, H. Ade, H. Yan, Aggregation and morphology control enables multiple cases of high-efficiency polymer solar cells. Nat Commun 5, 5293 (2014)ADSCrossRefGoogle Scholar
  9. 9.
    W. Zhao, S. Li, H. Yao, S. Zhang, Y. Zhang, B. Yang, J. Hou, Molecular optimization enables over 13% efficiency in organic solar cells. J Am Chem Soc 139, 7148–7151 (2017)CrossRefGoogle Scholar
  10. 10.
    Z. Fei, F.D. Eisner, X. Jiao, M. Azzouzi, J.A. Rohr, Y. Han, M. Shahid, A.S.R. Chesman, C.D. Easton, C.R. McNeill, T.D. Anthopoulos, J. Nelson, M. Heeney, An alkylated indacenodithieno 3,2-b thiophene-based nonfullerene acceptor with high crystallinity exhibiting single junction solar cell efficiencies greater than 13% with low voltage losses. Adv Mater 30, e1800728 (2018)CrossRefGoogle Scholar
  11. 11.
    J. Sun, X. Ma, Z. Zhang, J. Yu, J. Zhou, X. Yin, L. Yang, R. Geng, R. Zhu, F. Zhang, W. Tang, Dithieno 3,2-b:2 ‘,3 ‘-d pyrrol fused nonfullerene acceptors enabling over 13% efficiency for organic solar cells. Adv Mater 30, 1707150 (2018)CrossRefGoogle Scholar
  12. 12.
    H. Zhang, H. Yao, J. Hou, J. Zhu, J. Zhang, W. Li, R. Yu, B. Gao, S. Zhang, J. Hou, Over 14% efficiency in organic solar cells enabled by chlorinated nonfullerene small-molecule acceptors. Adv Mater 30, 1800613 (2018)CrossRefGoogle Scholar
  13. 13.
    C.E. Small, S.-W. Tsang, S. Chen, S. Baek, C.M. Amb, J. Subbiah, J.R. Reynolds, F. So, Loss mechanisms in thick-film low-bandgap polymer solar cells. Adv Energy Mater 3, 909–916 (2013)CrossRefGoogle Scholar
  14. 14.
    T.T. Larsen-Olsen, T.R. Andersen, B. Andreasen, A.P.L. Bottiger, E. Bundgaard, K. Norrman, J.W. Andreasen, M. Jorgensen, F.C. Krebs, Roll-to-roll processed polymer tandem solar cells partially processed from water. Sol Energy Mater Sol Cells 97, 43–49 (2012)CrossRefGoogle Scholar
  15. 15.
    Y. Sun, C.J. Takacs, S.R. Cowan, J.H. Seo, X. Gong, A. Roy, A.J. Heeger, Efficient, air-stable bulk heterojunction polymer solar cells using MoOx as the anode interfacial layer. Adv Mater 23, 2226 (2011)CrossRefGoogle Scholar
  16. 16.
    A. Pivrikas, N.S. Sariciftci, G. Juska, R. Osterbacka, A review of charge transport and recombination in polymer/fullerene organic solar cells. Prog Photovolt 15, 677–696 (2007)CrossRefGoogle Scholar
  17. 17.
    J. You, L. Dou, K. Yoshimura, T. Kato, K. Ohya, T. Moriarty, K. Emery, C.C. Chen, J. Gao, G. Li, Y. Yang, A polymer tandem solar cell with 10.6% power conversion efficiency. Nat Commun 4, 1446 (2013)ADSCrossRefGoogle Scholar
  18. 18.
    S. Sista, Z. Hong, M.-H. Park, Z. Xu, Y. Yang, High-efficiency polymer tandem solar cells with three-terminal structure. Adv Mater 22, 77 (2010)CrossRefGoogle Scholar
  19. 19.
    L. Zuo, X. Shi, S.B. Jo, Y. Liu, F. Lin, A.K.Y. Jen, Tackling energy loss for high-efficiency organic solar cells with integrated multiple strategies. Adv Mater 30, 1706816 (2018)CrossRefGoogle Scholar
  20. 20.
    G. Liu, J. Jia, K. Zhang, X.E. Jia, Q. Yin, W. Zhong, L. Li, F. Huang, Y. Cao, 15% efficiency tandem organic solar cell based on a novel highly efficient wide-bandgap nonfullerene acceptor with low energy loss. Adv Energy Mater 9, 1803657 (2019)CrossRefGoogle Scholar
  21. 21.
    Y. Zhang, B. Kan, Y. Sun, Y. Wang, R. Xia, X. Ke, C. Li, H.L. Yip, X. Wan, Y. Cao, Y. Chen, Nonfullerene tandem organic solar cells with high performance. Adv Mater 30, 1707508 (2018)CrossRefGoogle Scholar
  22. 22.
    F. Guo, P. Kubis, N. Li, T. Przybilla, G. Matt, T. Stubhan, T. Ameri, B. Butz, E. Spiecker, K. Forberich, C.J. Brabec, Solution-processed parallel tandem polymer solar cells using silver nanowires as intermediate electrode. ACS Nano 8, 12632–12640 (2014)CrossRefGoogle Scholar
  23. 23.
    L. Zuo, C.-C. Chueh, Y.-X. Xu, K.-S. Chen, Y. Zang, C.-Z. Li, H. Chen, A.K.Y. Jen, Microcavity-enhanced light-trapping for highly efficient organic parallel tandem solar cells. Adv Mater 26, 6778–6784 (2014)CrossRefGoogle Scholar
  24. 24.
    L. Zuo, J. Yu, X. Shi, F. Lin, W. Tang, A.K.Y. Jen, High-efficiency nonfullerene organic solar cells with a parallel tandem configuration. Adv Mater 29, 1702547 (2017)CrossRefGoogle Scholar
  25. 25.
    I. Etxebarria, A. Furlan, J. Ajuria, F.W. Fecher, M. Voigt, C.J. Brabec, M.M. Wienk, L. Slooff, S. Veenstra, J. Gilot, R. Pacios, Series vs parallel connected organic tandem solar cells: cell performance and impact on the design and operation of functional modules. Sol Energy Mater Sol Cells 130, 495–504 (2014)CrossRefGoogle Scholar
  26. 26.
    S.-H. Liao, H.-J. Jhuo, Y.-S. Cheng, S.-A. Chen, Fullerene derivative-doped zinc oxide nanofilm as the cathode of inverted polymer solar cells with low-bandgap polymer (PTB7-Th) for high performance. Adv Mater 25, 4766–4771 (2013)CrossRefGoogle Scholar
  27. 27.
    S. Zhang, L. Ye, J. Hou, Breaking the 10% efficiency barrier in organic photovoltaics: morphology and device optimization of well-known PBDTTT polymers. Adv Energy Mater 6, 1502529 (2016)CrossRefGoogle Scholar
  28. 28.
    Z. Xiao, X. Jia, D. Li, S. Wang, X. Geng, F. Liu, J. Chen, S. Yang, T.P. Russell, L. Ding, 26 mA cm(-2) J(sc) from organic solar cells with a low-bandgap nonfullerene acceptor. Sci Bull 62, 1494–1496 (2017)CrossRefGoogle Scholar
  29. 29.
    Y. Zang, Q. Xin, J. Zhao, J. Lin, Effect of active layer thickness on the performance of polymer solar cells based on a highly efficient donor material of PTB7-Th. J Phys Chem C 122, 16532–16539 (2018)CrossRefGoogle Scholar
  30. 30.
    P. Peumans, A. Yakimov, S.R. Forrest, Small molecular weight organic thin-film photodetectors and solar cells. J Appl Phys 93, 3693–3723 (2003)ADSCrossRefGoogle Scholar
  31. 31.
    Y. Zang, C.Z. Li, C.C. Chueh, S.T. Williams, W. Jiang, Z.H. Wang, J.S. Yu, A.K.Y. Jen, Integrated molecular, interfacial, and device engineering towards high-performance non-fullerene based organic solar cells. Adv Mater 26, 5708 (2014)CrossRefGoogle Scholar
  32. 32.
    N.P. Sergeant, A. Hadipour, B. Niesen, D. Cheyns, P. Heremans, P. Peumans, B.P. Rand, Design of transparent anodes for resonant cavity enhanced light harvesting in organic solar cells. Adv Mater 24, 728 (2012)CrossRefGoogle Scholar
  33. 33.
    K.S. Chen, H.L. Yip, J.F. Salinas, Y.X. Xu, C.C. Chueh, K.Y. Jen, Strong photocurrent enhancements in highly efficient flexible organic solar cells by adopting a microcavity configuration. Adv Mater 26, 3349–3354 (2014)CrossRefGoogle Scholar
  34. 34.
    H.W. Lin, S.W. Chiu, L.Y. Lin, Z.Y. Hung, Y.H. Chen, F. Lin, K.T. Wong, Device engineering for highly efficient top-illuminated organic solar cells with microcavity structures. Adv Mater 24, 2269–2272 (2012)CrossRefGoogle Scholar
  35. 35.
    J.F. Salinas, H.L. Yip, C.C. Chueh, C.Z. Li, J.L. Maldonado, A.K.Y. Jen, Optical design of transparent thin metal electrodes to enhance in-coupling and trapping of light in flexible polymer solar cells. Adv Mater 24, 6362–6367 (2012)CrossRefGoogle Scholar
  36. 36.
    B. Godefroid, G. Kozyreff, Photonic enhancement of parallel homo-tandem solar cells through the central electrode. Sol Energy Mater Sol Cells 193, 73–79 (2019)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Electronics and Information College, Hangzhou Dianzi UniversityHangzhouPeople’s Republic of China

Personalised recommendations