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Charge Carrier Dynamics in Polymer Solar Cells

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Organic Solar Cells

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Abstract

This chapter describes charge generation and recombination dynamics in polymer solar cells. Photovoltaic conversion mechanism in polymer solar cells ranges from femtoseconds to microseconds on a temporal scale. Therefore, time-resolved optoelectronic measurements are powerful tools for studying elementary processes in the photovoltaic conversion mechanism. First, the charge generation dynamics studied by transient absorption spectroscopy is described in order to discuss how polymer crystallinity and energy offsets at the interface have an impact on the charge dissociation in polymer/fullerene blends. In addition, the charge generation dynamics in ternary blends is also described. Next, the bimolecular recombination of free charge carriers studied by transient absorption spectroscopy and transient photovoltage and photocurrent measurements is discussed. Finally, challenging issues to be solved in polymer solar cells are discussed for further improvements in photovoltaic performance.

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  • 09 March 2021

    In the original version of the book, the following chapters corrections have been incorporated:

    The erratum chapters and book have been updated with the changes.

References

  1. Yu, G., Gao, J., Hummelen, J.C., Wudl, F., Heeger, A.J.: Polymer photovoltaic cells: Enhanced efficiencies via a network of internal donor–acceptor heterojunctions. Science 270, 1789–1791 (1995)

    Article  CAS  Google Scholar 

  2. Hall, J.J.M., Walsh, C.A., Greenham, N.C., Marseglia, E.A., Friend, R.H., Moratti, S.C., Holmes, A.B.: Efficient photodiodes from interpenetrating polymer networks. Nature 376, 498–500 (1995)

    Article  Google Scholar 

  3. 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 361, 1094–1098 (2018)

    Google Scholar 

  4. Liu, Q., Jiang, Y., Jin, K., Qin, J., Xu, J., Li, W., Xiong, J., Liu, J., Xiao, Z., Sun, K., Yang, S., Zhang, X., Ding, L.: 18% Efficiency organic solar cells. Bull. Sci. 65, 272–275 (2020)

    Google Scholar 

  5. Shaheen, S.E., Brabec, C.J., Sariciftci, N.S., Padinger, F., Fromherz, T., Hummelen, J.C.: 2.5% Efficient organic plastic solar cells. Appl. Phys. Lett. 78, 841–843 (2001)

    Google Scholar 

  6. Padinger, F., Rittberger, R.S., Sariciftci, N.S.: Effects of postproduction treatment on plastic solar cells. Adv. Funct. Mater. 13, 85–88 (2003)

    Article  CAS  Google Scholar 

  7. Peet, J., Kim, J.Y., Coates, N.E., Ma, W.L., Moses, D., Heeger, A.J., Bazan, G.C.: Efficiency enhancement in low-bandgap polymer solar cells by processing with alkane dithiols. Nat. Mater. 6, 497–500 (2007)

    Article  CAS  PubMed  Google Scholar 

  8. Lin, Y., Wang, J., Zhang, Z.-G., Bai, H., Li, Y., Zhu, D., Zhan, X.: An electron acceptor challenging fullerenes for efficient polymer solar cells. Adv. Mater. 27, 1170–1174 (2015)

    Article  CAS  PubMed  Google Scholar 

  9. Honda, S., Nogami, T., Ohkita, H., Benten, H., Ito, S.: Improvement of the light-harvesting efficiency in polymer/fullerene bulk heterojunction solar cells by interfacial dye modification. ACS Appl. Mater. Interf. 1, 804–810 (2009)

    Article  CAS  Google Scholar 

  10. Honda, S., Ohkita, H., Benten, H., Ito, S.: Multi-colored dye sensitization of polymer/fullerene bulk heterojunction solar cells. Chem. Commun. 46, 6596–6598 (2010)

    Article  CAS  Google Scholar 

  11. Honda, S., Ohkita, H., Benten, H., Ito, S.: Selective dye loading at the heterojunction in polymer/fullerene solar cells. Adv. Energy Mater. 1, 588–598 (2011)

    Article  CAS  Google Scholar 

  12. Xu, H., Ohkita, H., Tamai, Y., Benten, H., Ito, S.: Interface engineering for ternary blend polymer solar cells with a heterostructured near-IR dye. Adv. Mater. 27, 5868–5874 (2015)

    Article  CAS  PubMed  Google Scholar 

  13. Honda, S., Yokoya, S., Ohkita, H., Benten, H., Ito, S.: Light-harvesting mechanism in polymer/fullerene/dye ternary blend studied by transient absorption spectroscopy. J. Phys. Chem. C 115, 11306–11317 (2011)

    Article  CAS  Google Scholar 

  14. Ohkita, H., Ito, S.: Transient absorption spectroscopy of polymer-based thin-film solar cells. Polymer 52, 4397–4417 (2011)

    Article  CAS  Google Scholar 

  15. Ohkita, H., Ito, S.: Exciton and charge dynamics in polymer solar cells studied by transient absorption spectroscopy. In: Choy, W.C.H. (ed.) Organic Solar Cells, pp. 103–137. Springer-Verlag, London (2013)

    Chapter  Google Scholar 

  16. Ohkita, H., Tamai, Y., Benten, H., Ito, S.: Transient absorption spectroscopy for polymer solar cells. IEEE J. Sel. Top Quantum Electron. 22, 100–111 (2016)

    Google Scholar 

  17. Norrish, R.G.W., Porter, G.: Chemical reactions produced by very high light intensities. Nature 164, 658 (1949)

    Article  CAS  Google Scholar 

  18. Porter, G.: Flash photolysis and spectroscopy. A new method for the study of free radical reactions. Proc. R. Soc. London, Ser. A 200, 284–300 (1950)

    Google Scholar 

  19. Norrish, R.G.W.: Some fast reactions in gases studied by flash photolysis and kinetic spectroscopy. The official website of the Nobel Prize. https://www.nobelprize.org/prizes/chemistry/1967/norrish/lecture/ (1967). Accessed 8 November 2019

  20. Porter, G.: Flash photolysis and some of its applications. The official website of the Nobel Prize. https://www.nobelprize.org/prizes/chemistry/1967/porter/lecture/ (1967). Accessed 8 November 2019

  21. Zewail, A.: Femtochemistry: Atomic-scale dynamics of the chemical bond using ultrafast lasers. The official website of the Nobel Prize. https://www.nobelprize.org/prizes/chemistry/1999/zewail/lecture/ (1999). Accessed 8 November 2019

  22. Shuttle, C.G., O’Regan, B., Ballantyne, A.M., Nelson, J., Bradley, D.D.C., de Mello, J., Durrant, J.R.: Experimental determination of the rate law for charge carrier decay in a polythiophene:fullerene solar cell. Appl. Phys. Lett. 92, 093311 (2008)

    Article  Google Scholar 

  23. Maurano, A., Shuttle, C.G., Hamilton, R., Ballantyne, A.M., Nelson, J., Zhang, W., Heeney, M., Durrant, J.R.: Transient optoelectronics analysis of charge carrier losses in a selenophene/fullerene blend solar cell. J. Phys. Chem. C 115, 5947–5957 (2011)

    Article  CAS  Google Scholar 

  24. Credgington, D., Durrant, J.R.: Insights from transient optoelectronic analyses on the open-circuit voltage of organic solar cells. J. Phys. Chem. Lett. 3, 1465–1478 (2012)

    Article  CAS  PubMed  Google Scholar 

  25. Kirchartz, T., Nelson, J.: Meaning of reaction orders in polymer: fullerene solar cells. Phys. Rev. B 86, 165201 (2012)

    Article  Google Scholar 

  26. Guo, J., Ohkita, H., Benten, H., Ito, S.: Near-IR femtosecond transient absorption spectroscopy of ultrafast polarons and triplet formation in polythiophene films with different regioregularities. J. Am. Chem. Soc. 131, 16860–16880 (2009)

    Article  Google Scholar 

  27. Guo, J., Ohkita, H., Benten, H., Ito, S.: Charge generation and recombination dynamics in poly(3-hexylthiophene)/fullerene blend films with different regioregularites and morphologies. J. Am. Chem. Soc. 132, 6154–6164 (2010)

    Article  CAS  PubMed  Google Scholar 

  28. Ohkita, H., Kosaka, J., Guo, J., Benten, H., Ito, S.: Charge generation dynamics in polymer/polymer solar cells studied by transient absorption spectroscopy. J. Photon. Energy 1, 011118 (2011)

    Article  Google Scholar 

  29. Yamamoto, S., Ohkita, H., Benten, H., Ito, S.: Role of interfacial charge transfer state in charge generation and recombination in low-bandgap polymer solar cells. J. Phys. Chem. C 116, 14804–14810 (2012)

    Article  CAS  Google Scholar 

  30. Yamamoto, S., Ohkita, H., Benten, H., Ito, S., Yamamoto, S., Kitazawa, D., Tsukamoto, J.: Efficient charge generation and collection in amorphous polymer-based solar cells. J. Phys. Chem. C 117, 10277–10284 (2013)

    Article  Google Scholar 

  31. Ide, M., Koizumi, Y., Saeki, A., Izumiya, Y., Ohkita, H., Ito, S., Seki, S.: Near-infrared absorbing thienoisoindigo-based copolymers for organic photovoltaics. J. Phys. Chem. C 117, 26859–26870 (2013)

    Article  CAS  Google Scholar 

  32. Ie, Y., Karakawa, M., Jinnai, S., Yoshida, H., Saeki, A., Seki, S., Yamamoto, S., Ohkita, H., Aso, Y.: Electron-donor function of methanofullerenes in donor–acceptor bulk heterojunction systems. Chem. Commun. 50, 4123–4125 (2014)

    Article  CAS  Google Scholar 

  33. Yamamoto, S., Yasuda, H., Ohkita, H., Benten, H., Ito, S., Miyanishi, S., Tajima, K., Hashimoto, K.: Charge generation and recombination in fullerene-attached poly(3-hexylthiophene)-based diblock copolymer films. J. Phys. Chem. C 118, 10584–10589 (2014)

    Article  CAS  Google Scholar 

  34. Tamai, Y., Tsuda, K., Ohkita, H., Benten, H., Ito, S.: Charge-carrier generation in organic solar cells using crystalline donor polymers. Phys. Chem. Chem. Phys. 16, 20338–20346 (2014)

    Article  CAS  PubMed  Google Scholar 

  35. Mori, D., Benten, H., Ohkita, H., Ito, S.: Morphology-limited free carrier generation in donor/acceptor polymer blend solar cells composed of poly(3-hexylthiophene) and fluorene-based copolymer. Adv. Energy Mater. 5, 1500304 (2015)

    Article  Google Scholar 

  36. Kawashima, K., Tamai, Y., Ohkita, H., Osaka, I., Takimiya, K.: High-efficiency polymer solar cells with small photon energy loss. Nat. Commun. 6, 10085 (2015)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Tamai, Y., Ohkita, H., Namatame, M., Marumoto, K., Shimomura, S., Yamanari, T., Ito, S.: Light-induced degradation mechanism in poly(3-hexylthiophene)/fullerene blend solar cells. Adv. Energy Mater. 6, 1600171 (2016)

    Article  Google Scholar 

  38. Kawashima, K., Fukuhara, T., Suda, Y., Suzuki, Y., Koganezawa, T., Yoshida, H., Ohkita, H., Osaka, I., Takimiya, K.: Implication of fluorine atom on electronic properties, ordering structures, and photovoltaic performance in naphthobisthiadiazole-based semiconducting polymers. J. Am. Chem. Soc. 138, 10265–10275 (2016)

    Article  CAS  PubMed  Google Scholar 

  39. Gallaher, J.K., Prasad, S.K.K., Uddin, M.A., Kim, T., Kim, J.Y., Woo, H.Y., Hodgkiss, J.M.: Spectroscopically tracking charge separation in polymer: fullerene blends with a three-phase morphology. Energy Environ. Sci. 8, 2713–2724 (2015)

    Article  CAS  Google Scholar 

  40. Dennler, G., Scharber, M.C., Brabec, C.J.: Polymer-fullerene bulk-heterojunction solar cells. Adv. Mater. 21, 1323–1338 (2009)

    Article  CAS  Google Scholar 

  41. Veldman, D., Meskers, S.C.J., Janssen, R.A.: The energy of charge-transfer states in electron donor–acceptor blends: Insight into the energy losses in organic solar cells. Adv. Funct. Mater. 19, 1939–1948 (2009)

    Article  CAS  Google Scholar 

  42. Wang, Y., Qian, D., Cui, Y., Zhang, H., Hou, J., Vandewal, K., Kirchartz, T., Gao, F.: Optical gaps of organic solar cells as a reference for comparing voltage losses. Adv. Energy Mater. 8, 1801352 (2018)

    Article  Google Scholar 

  43. Xu, H., Wada, T., Ohkita, H., Benten, H., Ito, S.: Molecular design of near-IR dyes with different surface energy for selective loading to the heterojunction in blend films. Sci. Rep. 5, 9321 (2015)

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  44. Guo, J., Ohkita, H., Yokoya, S., Benten, H., Ito, S.: Bimodal polarons and hole transport in poly(3-hexylthiophene):fullerene blend films. J. Am. Chem. Soc. 132, 9631–9637 (2010)

    Article  CAS  PubMed  Google Scholar 

  45. Fukuhara, T., Osaka, M., Tamai, Y., Ohkita, H., Benten, H., Ito, S.: Reduced bimolecular recombination in polymer solar cells. J. Photopolym. Sci. Technol. 29, 575–580 (2016)

    Article  CAS  Google Scholar 

  46. Fukuhara, T., Tamai, Y., Osaka, I., Ohkita, H.: Bimolecular recombination and fill factor in crystalline polymer solar cells. Jpn. J. Appl. Phys. 57, 08RE01 (2018)

    Google Scholar 

  47. Nelson, J.: Diffusion-limited recombination in polymer–fullerene blends and its influence on photocurrent collection. Phys. Rev. B 67, 155209 (2003)

    Article  Google Scholar 

  48. Tachiya, M., Seki, K.: Theory of bulk electron–hole recombination in a medium with energetic disorder. Phys. Rev. B 82, 085201 (2010)

    Article  Google Scholar 

  49. Koster, L.J.A., Mihailetchi, V.D., Blom, P.W.M.: Bimolecular recombination in polymer/fullerene bulk heterojunction solar cells. Appl. Phys. Lett. 88, 052104 (2006)

    Article  Google Scholar 

  50. Pivrikas, A., Juška, G., Mozer, A., Scharber, M., Arlauskas, K., Sariciftici, N.S., Stubb, H., Österbacka, R.: Bimolecular recombination coefficient as a sensitive testing parameter for low-mobility solar-cell materials. Phys. Rev. Lett. 94, 176806 (2005)

    Article  CAS  PubMed  Google Scholar 

  51. Chen, D., Nakahara, A., Wei, D., Nordlund, D., Russell, T.P.: P3HT/PCBM bulk heterojunction organic photovoltaics: correlating efficiency and morphology. Nano Lett. 11, 561–567 (2011)

    Article  CAS  PubMed  Google Scholar 

  52. Salleo, A., Kline, R.J., DeLongchamp, D.M., Chabinyc, M.L.: Microstructural characterization and charge transport in thin films of conjugated polymers. Adv. Mater. 22, 3812–3838 (2010)

    Article  CAS  PubMed  Google Scholar 

  53. Motaung, D.E., Malgas, G.F., Arendse, C.J.: Correlation between the morphology and photo-physical properties of P3HT:fullerene blends. J. Mater. Sci. 45, 3276–3283 (2010)

    Article  CAS  Google Scholar 

  54. Chen, H.-Y., Hou, J., Hayden, A.E., Yang, H., Houk, K.N., Yang, Y.: Silicon atom substitution enhances interchain packing in a thiophene-based polymer system. Adv. Mater. 22, 371–375 (2010)

    Article  CAS  PubMed  Google Scholar 

  55. Guilbert, A.A., Frost, J.M., Agostinelli, T., Pires, E., Lilliu, S., Macdonald, J.E., Nelson, J.: Influence of bridging atom and side chains on the structure and crystallinity of cyclopentadithiophene-bennzothiadiazole polymers. Chem. Mater. 26, 1226–1233 (2014)

    Article  CAS  Google Scholar 

  56. Ohkita, H., Cook, S., Astuti, Y., Duffy, W., Tierney, S., Zhang, W., Heeney, M., McCulloch, I., Nelson, J., Bradley, D.D.C., Durrant, J.R.: Charge carrier formation in polythiophene/fullerene blend films studied by transient absorption spectroscopy. J. Am. Chem. Soc. 130, 3030–3042 (2008)

    Article  CAS  PubMed  Google Scholar 

  57. Clarke, T.M., Durrant, J.R.: Charge photogeneration in organic solar cells. Chem. Rev. 110, 6736–6767 (2010)

    Article  CAS  PubMed  Google Scholar 

  58. Gregg, B.A.: Entropy of charge separation in organic photovoltaic cells: The benefit of higher dimensionality. J. Phys. Chem. Lett. 2, 3013–3015 (2011)

    Article  CAS  Google Scholar 

  59. Deibel, C., Strobel, T., Dyakonov, V.: Origin of the efficient polaron-pair dissociation in polymer-fullerene blends. Phys. Rev. Lett. 103, 036402 (2009)

    Article  PubMed  Google Scholar 

  60. Savoie, B.M., Rao, A., Bakulin, A.A., Gelinas, S., Movaghar, B., Friend, R.H., Marks, T.J., Ratner, M.A.: Unequal partnership: asymmetric roles of polymeric donor and fullerene acceptor in generating free charge. J. Am. Chem. Soc. 136, 2876–2884 (2014)

    Article  CAS  PubMed  Google Scholar 

  61. Gélinas, S., Rao, A., Kumar, A., Smith, S.L., Chin, A.W., Clark, J., van der Poll, T.S., Bazan, G.C., Friend, R.H.: Ultrafast long-range charge separation in organic semiconductor photovoltaic diodes. Science 343, 512–516 (2014)

    Article  PubMed  Google Scholar 

  62. Li, G., Shrotriya, V., Huang, J., Yao, Y., Moriarty, T., Emery, K., Yang, Y.: High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends. Nat. Mater. 4, 864–868 (2005)

    Article  CAS  Google Scholar 

  63. Li, W., Hendriks, K.H., Roelofs, W.S.C., Kim, Y., Wienk, M.M., Janssen, R.A.J.: Efficient small bandgap polymer solar cells with high fill factors for 300 nm thick films. Adv. Mater. 25, 3182–3186 (2013)

    Article  CAS  PubMed  Google Scholar 

  64. Izawa, S., Nakano, K., Suzuki, K., Hashimoto, K., Tajima, K.: Dominant effects of first monolayer energetics at donor/acceptor interfaces on organic photovoltaics. Adv. Mater. 27, 3025–3031 (2015)

    Article  CAS  PubMed  Google Scholar 

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Acknowledgements

Most of the studies in this chapter were conducted with Professor Emeritus Ito at Kyoto University and Associate Professor Benten at Nara Institute of Science and Technology. They have been done mainly by Dr Guo, Dr Yamamoto, Dr Honda, and Dr Tamai. They were partly supported by the JST PRESTO program (Photoenergy and Conversion Systems and Materials for the Next-Generation Solar Cells) and the JST ALCA program (Solar Cell and Solar Energy Systems: JPMJAL1404).

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  1. Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura Campus, Kyoto, Nishikyo-Ku, 615-8510, Japan

    Hideo Ohkita

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  1. Hideo Ohkita
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Correspondence to Hideo Ohkita .

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  1. Department of Materials Molecular Science, Institute for Molecular Science, Okazaki, Aichi, Japan

    Masahiro Hiramoto

  2. Institute for Molecular Science, Okazaki, Aichi, Japan

    Seiichiro Izawa

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Ohkita, H. (2021). Charge Carrier Dynamics in Polymer Solar Cells. In: Hiramoto, M., Izawa, S. (eds) Organic Solar Cells. Springer, Singapore. https://doi.org/10.1007/978-981-15-9113-6_6

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