Effects of BTA2 as the third component on the charge carrier generation and recombination behavior of PTB7:PC71BM photovoltaic system

Abstract

Effects of a benzotriazole (BTA)-based small molecule, BTA2, as the third component on the charge carrier generation and recombination behavior of poly [[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b’]dithio-phene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno [3,4-b]thiophenediyl]] (PTB7): [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) organic solar cells (OSCs) were investigated by optical simulation of a transfer matrix model (TMM), photo-induced charge extraction by linearly increasing voltage (photo-CELIV) technique, atomic force microscope (AFM), and the Onsager-Braun model analysis. BTA2 is an A2-A1-D-A1-A2-type non-fullerene small molecule with thiazolidine-2,4-dione, BTA, and indacenodithiophene as the terminal acceptor (A2), bridge acceptor (A1), and central donor (D), respectively. The short-circuit current density of the OSCs with BTA2 can be enhanced significantly owing to a complementary absorption spectrum. The optical simulation of TMM shows that the ternary OSCs exhibit higher internal absorption than the traditional binary OSCs without BTA2, resulting in more photogenerated excitons in the ternary OSCs. The photo-CELIV investigation indicates that the ternary OSCs suffer higher charge trap-limited bimolecular recombination than the binary OSCs. AFM images show that BTA2 aggravates the phase separation between the donor and the acceptor, which is disadvantageous to charge carrier transport. The Onsager-Braun model analysis confirms that despite the charge collection efficiency of the ternary OSCs being lower than that of the binary OSCs, the optimized photon absorption and exciton generation processes of the ternary OSCs achieve an increase in photogenerated current and thus improve power conversion efficiency.

This is a preview of subscription content, log in to check access.

References

  1. 1.

    Heeger A J. 25th anniversary article: Bulk heterojunction solar cells: Understanding the mechanism of operation. Advanced Materials, 2014, 26(1): 10–28

    CAS  Article  Google Scholar 

  2. 2.

    Lin Y Z, Li Y F, Zhan X W. Small molecule semiconductors for high-efficiency organic photovoltaics. Chemical Society Reviews, 2012, 41(11): 4245–4272

    CAS  Article  Google Scholar 

  3. 3.

    Espinosa N, Hosel M, Jorgensen M, Krebs F C. Large scale deployment of polymer solar cells on land, on sea and in the air. Energy & Environmental Science, 2014, 7(3): 855–866

    CAS  Article  Google Scholar 

  4. 4.

    Jensen J, Hosel M, Dyer A L, Krebs F C. Development and manufacture of polymer-based electrochromic devices. Advanced Functional Materials, 2015, 25(14): 2073–2090

    CAS  Article  Google Scholar 

  5. 5.

    Thompson B C, Frechet J M J. Organic photovoltaics-polymer-fullerene composite solar cells. Angewandte Chemie International Edition, 2008, 47(1): 58–77

    CAS  Article  Google Scholar 

  6. 6.

    Brabec C J, Heeney M, McCulloch I, Nelson J. Influence of blend microstructure on bulk heterojunction organic photovoltaic performance. Chemical Society Reviews, 2011, 40(3): 1185–1199

    CAS  Article  Google Scholar 

  7. 7.

    Cao W R, Xue J G. Recent progress in organic photovoltaics: Device architecture and optical design. Energy & Environmental Science, 2014, 7(7): 2123–2144

    CAS  Article  Google Scholar 

  8. 8.

    Lu L Y, Zheng T Y, Wu Q H, Schneider A M, Zhao D L, Yu L P. Recent advances in bulk heterojunction polymer solar cells. Chemical Reviews, 2015, 115(23): 12666–12731

    CAS  Article  Google Scholar 

  9. 9.

    Ye L, Zhang S Q, Huo L J, Zhang M J, Hou J H. Molecular design toward highly efficient photovoltaic polymers based on two-dimensional conjugated benzodithiophene. Accounts of Chemical Research, 2014, 47(5): 1595–1603

    CAS  Article  Google Scholar 

  10. 10.

    Liang Y Y, Wu Y, Feng D Q, Tsai S T, Son H J, Li G, Yu L P. Development of new semiconducting polymers for high performance solar cells. Journal of the American Chemical Society, 2009, 131(1): 56–57

    CAS  Article  Google Scholar 

  11. 11.

    Fu H T, Wang Z H, Sun Y M. Polymer donors for high-performance non-fullerene organic solar cells. Angewandte Chemie International Edition, 2019, 58(14): 4442–4453

    CAS  Article  Google Scholar 

  12. 12.

    Chen C C, Chang W H, Yoshimura K, Ohya K, You J B, Gao J, Hong Z R, Yang Y. An efficient triple-junction polymer solar cell having a power conversion efficiency exceeding 11%. Advanced Materials, 2014, 26(32): 5670–5677

    CAS  Article  Google Scholar 

  13. 13.

    Li S S, Ye L, Zhao W C, Zhang S Q, Mukherjee S, Ade H, Hou J H. Energy-level modulation of small-molecule electron acceptors to achieve over 12% efficiency in polymer solar cells. Advanced Materials, 2016, 28(42): 9423–9429

    CAS  Article  Google Scholar 

  14. 14.

    Nian L, Gao K, Liu F, Kan Y Y, Jiang X F, Liu L L, Xie Z Q, Peng X B, Russell T P, Ma Y G. 11% efficient ternary organic solar cells with high composition tolerance via integrated near-IR sensitization and interface engineering. Advanced Materials, 2016, 28(37): 8184–8190

    CAS  Article  Google Scholar 

  15. 15.

    Zhao W C, Li S S, Yao H F, Zhang S Q, Zhang Y, Yang B, Hou J H. Molecular optimization enables over 13% efficiency in organic solar cells. Journal of the American Chemical Society, 2017, 139(21): 7148–7151

    CAS  Article  Google Scholar 

  16. 16.

    Li MM, Gao K, Wan X J, Zhang Q, Kan B, Xia R X, Liu F, Yang X, Feng H R, Ni W, et al. Solution-processed organic tandem solar cells with power conversion efficiencies > 12%. Nature Photonics, 2017, 11(2): 85–90

    CAS  Article  Google Scholar 

  17. 17.

    Liu Q, Jiang Y, Jin K, Qin J Q, Xu J G, Li W T, Xiong J, Liu J F, Xiao Z, Sun K, et al. 18% efficiency organic solar cells. Science Bulletin, 2020, doi:https://doi.org/10.1016/j.scib.2020.01.001 (in press)

  18. 18.

    Meng L, Zhang Y, Wan X, Li C, Zhang X, Wang Y, Ke X, Xiao Z, Ding L, Xia R, Yip H L, Cao Y, Chen Y. Organic and solution-processed tandem solar cells with 17.3% efficiency. Science, 2018, 361(6407): 1094–1098

    CAS  Article  Google Scholar 

  19. 19.

    Qi B Y, Wang J Z. Fill factor in organic solar cells. Physical Chemistry Chemical Physics, 2013, 15(23): 8972–8982

    CAS  Article  Google Scholar 

  20. 20.

    Chen Z H, Cai P, Chen J W, Liu X C, Zhang L J, Lan L F, Peng J B, Ma Y G, Cao Y. Low band-gap conjugated polymers with strong interchain aggregation and very high hole mobility towards highly efficient thick-film polymer solar cells. Advanced Materials, 2014, 26(16): 2586–2591

    CAS  Article  Google Scholar 

  21. 21.

    Cui Y, Yang C Y, Yao H F, Zhu J, Wang Y M, Jia G X, Gao F, Hou J H. Efficient semitransparent organic solar cells with tunable color enabled by an ultralow-bandgap nonfullerene acceptor. Advanced Materials, 2017, 29(43): 1703080

    Article  Google Scholar 

  22. 22.

    Deshmukh K D, Qin T S, Gallaher J K, Liu A C Y, Gann E, O’Donnell K, Thomsen L, Hodgkiss J M, Watkins S E, McNeill C R. Performance, morphology and photophysics of high open-circuit voltage, low band gap all-polymer solar cells. Energy & Environmental Science, 2015, 8(1): 332–342

    CAS  Article  Google Scholar 

  23. 23.

    Yao H F, Cui Y, Yu R N, Gao B W, Zhang H, Hou J H. Design, synthesis, and photovoltaic characterization of a small molecular acceptor with an ultra-narrow band gap. Angewandte Chemie International Edition, 2017, 56(11): 3045–3049

    CAS  Article  Google Scholar 

  24. 24.

    Gasparini N, Jiao X C, Heumueller T, Baran D, Matt G J, Fladischer S, Spiecker E, Ade H, Brabec C J, Ameri T. Designing ternary blend bulk heterojunction solar cells with reduced carrier recombination and a fill factor of 77%. Nature Energy, 2016, 1(9): 16118–16122

    CAS  Article  Google Scholar 

  25. 25.

    Ameri T, Li N, Brabec C J. Highly efficient organic tandem solar cells: A follow up review. Energy & Environmental Science, 2013, 6(8): 2390–2413

    CAS  Article  Google Scholar 

  26. 26.

    Ameri T, Dennler G, Lungenschmied C, Brabec C J. Organic tandem solar cells: A review. Energy & Environmental Science, 2009, 2(4): 347–363

    CAS  Article  Google Scholar 

  27. 27.

    Zuo L J, Yu J S, Shi X L, Lin F, Tang W H, Jen A K Y. High-efficiency nonfullerene organic solar cells with a parallel tandem configuration. Advanced Materials, 2017, 29(34): 1702547

    Article  Google Scholar 

  28. 28.

    Farahat M E, Patra D, Lee C H, Chu C W. Synergistic effects of morphological control and complementary absorption in efficient all-small-molecule ternary-blend solar cells. ACS Applied Materials & Interfaces, 2015, 7(40): 22542–22550

    CAS  Article  Google Scholar 

  29. 29.

    Xiao B, Tang A L, Zhang J Q, Mahmood A, Wei Z X, Zhou E J. Achievement of high Voc of 1.02 V for P3HT-based organic solar cell using a benzotriazole-containing non-fullerene acceptor. Advanced Energy Materials, 2017, 7(8): 1602269

    Article  Google Scholar 

  30. 30.

    Xiao B, Tang A L, Yang J, Wei Z X, Zhou E. P3HT-based photovoltaic cells with a high Voc of 1.22 V by using a benzotriazole-containing nonfullerene acceptor end-capped with thiazolidine-2,4-dione. ACS Macro Letters, 2017, 6(4): 410–414

    CAS  Article  Google Scholar 

  31. 31.

    Tang A L, Song W, Xiao B, Guo J, Min J, Ge Z Y, Zhang J Q, Wei Z X, Zhou E J. Benzotriazole-based acceptor and donors, coupled with chlorination, achieve a high Voc of 1.24 V and an efficiency of 10.5% in fullerene-free organic solar cells. Chemistry of Materials, 2019, 31(11): 3941–3947

    CAS  Article  Google Scholar 

  32. 32.

    Zhang H, Liu Y, Xu B, Chen G, Wang C, Wen S P, Li Y W, Liu L J, Tian W J. Effects of DIO on the charge recombination behaviors of PTB7:PC71BMphotovoltaics. Organic Electronics, 2019, 67: 50–56

    CAS  Article  Google Scholar 

  33. 33.

    Liu Y, Qian J Y, Zhang H, Xu B, Zhang Y P, Liu L J, Chen G, Tian W J. Influence of organic cations on intrinsic properties of lead iodide perovskite solar cells. Organic Electronics, 2018, 62: 269–276

    Article  Google Scholar 

  34. 34.

    Park H, An J, Song J, Lee M, Ahn H, Jahnel M, Im C. Thickness-dependent internal quantum efficiency of narrow band-gap polymer-based solar cells. Solar Energy Materials and Solar Cells, 2015, 143: 242–249

    CAS  Article  Google Scholar 

  35. 35.

    Groves C, Greenham N C. Bimolecular recombination in polymer electronic devices. Physical Review B, 2008, 78(15): 155205

    Article  Google Scholar 

  36. 36.

    Keivanidis P E, Kamm V, Dyer-Smith C, Zhang W M, Laquai F, McCulloch I, Bradley D D C, Nelson J. Delayed luminescence spectroscopy of organic photovoltaic binary blend films: Probing the emissive non-geminate charge recombination. Advanced Materials, 2010, 22(45): 5183–5187

    CAS  Article  Google Scholar 

  37. 37.

    Liu Y, Gao Y J, Xu B, van Loosdrecht P H M, Tian W J. Trap-limited bimolecular recombination in poly(3-hexylthiophene): Fullerene blend films. Organic Electronics, 2016, 38: 8–14

    Article  Google Scholar 

  38. 38.

    Mozer A J, Dennler G, Sariciftci N S, Westerling M, Pivrikas A, Osterbacka R, Juska G. Time-dependent mobility and recombination of the photoinduced charge carriers in conjugated polymer/fullerene bulk heterojunction solar cells. Physical Review B, 2005, 72(3): 035217

    Article  Google Scholar 

  39. 39.

    Pivrikas A, Sariciftci N S, Juska G, Osterbacka R. A review of charge transport and recombination in polymer/fullerene organic solar cells. Progress in Photovoltaics: Research and Applications, 2007, 15(8): 677–696

    CAS  Article  Google Scholar 

  40. 40.

    Liu D Y, Yang J L, Kelly T L. Compact layer free perovskite solar cells with 13.5% efficiency. Journal of the American Chemical Society, 2014, 136(49): 17116–17122

    CAS  Article  Google Scholar 

Download references

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Grant No. 21811540393), Program for Changbaishan Scholars of Jilin Province, and the “Talents Cultivation Program” of Jilin University.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Wenjing Tian.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Liu, L., Zhang, H., Xiao, B. et al. Effects of BTA2 as the third component on the charge carrier generation and recombination behavior of PTB7:PC71BM photovoltaic system. Front. Chem. Sci. Eng. (2020). https://doi.org/10.1007/s11705-020-1936-7

Download citation

Keywords

  • third component
  • organic solar cells
  • charge carrier generation
  • charge carrier recombination
  • bimolecular recombination