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Open-Circuit Voltage in Organic Solar Cells

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Organic Solar Cells

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Abstract

Organic solar cells (OSCs) based on blends of electron donor (D) and acceptor (A) semiconducting materials now have a power conversion efficiency exceeding 17%, and 100% internal quantum efficiency of free charge generation has already been realized. Therefore, reducing the energy loss in the open-circuit voltage (VOC) is critically important for further enhancing the efficiency of OSCs. In this chapter, the background and recent findings concerning VOC in OSCs are reviewed, beginning with an explanation of the photoconversion mechanism in OSCs in relation to VOC. Following this, the empirical understanding of VOC is outlined, and the models used for explaining the determination of VOC in OSCs are described. In the next section, recent progress for increasing VOC in OSCs by modifying the D/A interface is summarized. The topics discussed are energy-level alignment, doping, the pn homojunction, energy-level control at the monolayer scale, crystallinity, and functionalization of acceptor molecules. Finally, ways in which the VOC in OSCs can be maximized are proposed with a view to the future.

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References

  1. Dou, L., You, J., Hong, Z., Xu, Z., Li, G., Street, R.A., Yang, Y.: 25th Anniversary article—a decade of organic/polymeric photovoltaic research. Adv. Mater. 25, 6642–6671 (2013)

    Article  CAS  Google Scholar 

  2. Liu, L., Kan, Y., Gao, K., Wang, J., Zhao, M., Chen, H., Zhao, C., Jiu, T., Jen, A.K.Y., Li, Y.: Graphdiyne derivative as multifunctional solid additive in binary organic solar cells with 17.3% efficiency and high reproductivity. Adv. Mater. 32, 1907604 (2020)

    Google Scholar 

  3. Hiramoto, M., Fujiwara, H., Yokoyama, M.: Three-layered organic solar cell with a photoactive interlayer of codeposited pigment. Appl. Phys. Lett. 58, 1062–1064 (1991)

    Article  CAS  Google Scholar 

  4. 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 

  5. Lu, L., Zheng, T., Wu, Q., Schneider, A. M., Zhao, D., Yu, L.: Recent advances in bulk heterojunction polymer solar cells. Chem. Rev. 115, 12666–12731 (2015)

    Google Scholar 

  6. Hou, J., Inganäs, O., Friend, R., Gao, F.: Organic solar cells based on non-fullerene acceptors. Nat. Mater. 17, 119–128 (2018)

    Article  CAS  Google Scholar 

  7. National Renewable Energy Laboratory, Best Research-Cell Efficiency Chart (2019)

    Google Scholar 

  8. Baran, D., Gasparini, N., Wadsworth, A., Tan, C.H., Wehbe, N., Song, X., Hamid, Z., Zhang, W., Neophytou, M., Kirchartz, T., Brabec, C.J., Durrant, J.R., McCulloch, I.: Robust nonfullerene solar cells approaching unity external quantum efficiency enabled by suppression of geminate recombination. Nat. Commun. 9, 2059 (2018)

    Article  Google Scholar 

  9. Park, S.H., Roy, A., Beaupré, S., Cho, S., Coates, N., Moon, J.S., Moses, D., Leclerc, M., Lee, K., Heeger, A.J.: Bulk heterojunction solar cells with internal quantum efficiency approaching 100%. Nat. Photon. 3, 297–295 (2009)

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  11. Knupfer, M.: Exciton binding energies in organic semiconductors. Appl. Phys. A 77, 623–626 (2003)

    Article  CAS  Google Scholar 

  12. Kroeze, J.E., Savenije, T.J., Vermeulen, M.J.W., Warman, J.M.: Contactless determination of the photoconductivity action spectrum, exciton diffusion length, and charge separation efficiency in polythiophene-sensitized TiO2 bilayers. J. Phys. Chem. B 107, 7696–7705 (2003)

    Article  CAS  Google Scholar 

  13. Vandewal, K., Himmelberger, S., Salleo, A.: Structural factors that affect the performance of organic bulk heterojunction solar cells. Macromolecules 46, 6379–6387 (2013)

    Article  CAS  Google Scholar 

  14. Benduhn, J., Tvingstedt, K., Piersimoni, F., Ullbrich, S., Fan, Y., Tropiano, M., McGarry, K.A., Zeika, O., Riede, M.K., Douglas, C.J., Barlow, S., Marder, S.R., Neher, D., Spoltore, D., Vandewal, K.: Intrinsic non-radiative voltage losses in fullerene-based organic solar cells. Nat. Energy 2, 17053 (2017)

    Article  CAS  Google Scholar 

  15. Shintaku, N., Hiramoto, M., Izawa, S.: Effect of trap-assisted recombination on open-circuit voltage loss in phthalocyanine/fullerene solar cells. Org. Electron. 55, 69–74 (2018)

    Article  CAS  Google Scholar 

  16. Scharber, M.C., Wuhlbacher, D., Koppe, M., Denk, P., Waldauf, C., Heeger, A.J., Brabec, C.L.: Design rules for donors in bulk-heterojunction solar cells—towards 10% energy-conversion efficiency. Adv. Mater. 18, 789–794 (2006)

    Article  CAS  Google Scholar 

  17. Yoshida, H.: Near-ultraviolet inverse photoemission spectroscopy using ultra-low energy electrons. Chem. Phys. Lett. 539–540, 180–185 (2012)

    Article  Google Scholar 

  18. Izawa, S., Shintaku, N., Hiramoto, M.: Effect of band bending and energy level alignment at the donor/acceptor interface on open-circuit voltage in organic solar cells. J. Phys. Chem. Lett. 9, 2914–2918 (2018)

    Article  CAS  Google Scholar 

  19. Street, R.A., Hawks, S.A., Khlyabich, P.P., Li, G., Schwartz, B.J., Thompson, B.C., Yang, Y.: Electronic structure and transition energies in polymer-fullerene bulk heterojunctions. J. Phys. Chem. C 118, 21873–21883 (2014)

    Article  CAS  Google Scholar 

  20. 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  Google Scholar 

  21. Sze, S.M.: Physics of semiconductor devices (2005)

    Google Scholar 

  22. Zhong, Y., Tada, A., Izawa, S., Hashimoto, K., Tajima, K.: Enhancement of VOC without loss of JSC in organic solar cells by modification of donor/acceptor interfaces. Adv. Energy Mater. 4, 1301332 (2014)

    Article  Google Scholar 

  23. Vandewal, K., Tvingstedt, K., Gadisa, A., Inganas, O., Manca, J.V.: On the origin of the open-circuit voltage of polymer–fullerene solar cells. Nature Mater. 8, 904–909 (2009)

    Article  CAS  Google Scholar 

  24. Vandewal, K., Tvingstedt, K., Gadisa, A., Inganas, O., Manca, J.V.: Relating the open-circuit voltage to interface molecular properties of donor:acceptor bulk heterojunction solar cells. Phys. Rev. B 81, 125204 (2010)

    Article  Google Scholar 

  25. Shockley, W., Queisser, H.J.: Detailed balance limit of efficiency of pn junction solar cells. J. Appl. Phys. 32, 510–519 (1961)

    Article  CAS  Google Scholar 

  26. Yang, J.-P., Bussolotti, F., Kera, S., Ueno, N.: Origin and role of gap states in organic semiconductor studied by UPS: as the nature of organic molecular crystals. J. Phys. D Appl. Phys. 50, 423002 (2017)

    Article  Google Scholar 

  27. Shintaku, N., Hiramoto, M., Izawa, S.: Doping for controlling open-circuit voltage in organic solar cells. J. Phys. Chem. C 122, 5248–5253 (2018)

    Article  CAS  Google Scholar 

  28. Izawa, S., Perrot, A., Lee, J., Hiramoto, M.: Organic pnhomojunction solar cell. Org. Electron. 71, 45–49 (2019)

    Article  CAS  Google Scholar 

  29. Horlet, M., Kraus, M., Brütting, W., Opitz, A.: Diindenoperylene as ambipolar semiconductor:influence of electrode materials and mobility asymmetry in organicfield-effect transistors. Appl. Phys. Lett. 98, 233304 (2011)

    Article  Google Scholar 

  30. Lee, J., Perrot, A., Hiramoto, M., Izawa, S.: Photoconversion mechanism at the pn-HomojunctionInterface in single organic semiconductor. Materials 13, 1727 (2020)

    Article  CAS  Google Scholar 

  31. Hegedus, S.S., Shafarman, W.N.: Thin-film solar cells: device measurementsand analysis. Prog. Photovolt. Res. Appl. 12, 155–176 (2004)

    Article  CAS  Google Scholar 

  32. Burke, T.M., Sweetnam, S., Vandewal, K., McGehee, M.D.: Beyond Langevin recombination: How equilibrium between free carriers and charge transfer states determines the open-circuit voltage of organic solar Cells. Adv. Energy Mater. 5, 1500123 (2015)

    Article  Google Scholar 

  33. Wei, Q., Tajima, K., Tong, Y., Ye, S., Hashimoto, K.: Surface-segregated monolayers: a new type of ordered monolayer for surface modification of organic semiconductors. J. Am. Chem. Soc. 131, 17597 (2009)

    Article  CAS  Google Scholar 

  34. Lenes, M., Wetzelaer, G.-J.A.H., Kooistra, F.B., Veenstra, S.C., Hummelen, J.C., Blom, P.W.M.: Fullerene bisadducts for enhanced open-circuit voltages and efficiencies in polymer solar cells. Adv. Mater. 20, 2116 (2008)

    Article  CAS  Google Scholar 

  35. Izawa, S., Shintaku, N., Kikuchi, M., Hiramoto, M.: Importance of interfacial crystallinity to reduce open-circuit voltage loss in organic solar cells. Appl. Phys. Lett. 115, 153301 (2019)

    Article  Google Scholar 

  36. Yuan, Y., Giri, G., Ayzner, A.L., Zoombelt, A.P., Mannsfeld, S.C., Chen, J., Nordlund, D., Toney, M.F., Huang, J., Bao, Z.: Ultra-high mobility transparent organic thin film transistors grown by an off-centre spin-coating method. Nat. Commun. 5, 3005 (2014)

    Article  Google Scholar 

  37. Chesterfield, R.J., McKeen, J.C., Newman, C.R., Ewbank, P.C., da Silva, D.A., Bredas, J.L., Miller, L.L., Mann, K.R., Frisbie, C.D.: Organic thin film transistors based on N-alkyl perylenediimides: Charge transport kinetics as a function of gate voltage and temperature. J. Phys. Chem. B 108, 19281–19292 (2004)

    Article  CAS  Google Scholar 

  38. Wagner, J., Gruber, M., Hinderhofer, A., Wilke, A., Bröker, B., Frisch, J., Amsalem, P., Vollmer, A., Opitz, A., Koch, N., Schreiber, F., Brütting, W.: High fill factor and open circuit voltage in organic photovoltaic cells with Diindenoperylene as donor material. Adv. Funct. Mater. 20, 4295–4303 (2010)

    Article  CAS  Google Scholar 

  39. Illig, S., Eggeman, A., Troisi, A., Jiang, L., Warwick, C., Nikolka, M., Schweicher, G., Yeates, S.G., Geerts, Y.H., Anthony, J.E., Sirringhaus, H.: Reducing dynamic disorder in small-molecule organic semiconductors by suppressing large-amplitude thermal motions. Nat. Commun. 7, 10736 (2016)

    Article  CAS  Google Scholar 

  40. Fujimoto, K., Izawa, S., Arikai, Y., Sugimoto, S., Oue, H., Inuzuka, T., Uemura, N., Sakamoto, M., Hiramoto, M., Takahashi, M.: Regioselective bay-functionalization of perylenes toward tailor-made synthesis of acceptor materials for organic photovoltaics. ChemPlusChem 85, 285–293 (2020)

    Article  CAS  Google Scholar 

  41. Qian, D., Zheng, Z., Yao, H., Tress, W., Hopper, T.R., Chen, S., Li, S., Liu, J., Chen, S., Zhang, J., Liu, X.-K., Gao, B., Ouyang, L., Jin, Y., Pozina, G., Buyanova, I.A., Chen, W.M., Inganäs, O., Coropceanu, V., Bredas, J.-L., Yan, H., Hou, J., Zhang, F., Bakulin, A.A., Gao, F.: Design rules for minimizing voltage losses in high-efficiency organic solar cells. Nature Mater. 17, 703–709 (2018)

    Article  CAS  Google Scholar 

  42. Eisner, F.D., Azzouzi, M., Fei, Z., Hou, X., Anthopoulos, T.D., John, T., Dennis, S., Heeney, M., Nelson, J.: Hybridization of local exciton and charge-transfer states reduces nonradiative voltage losses in organic solar cells. J. Am. Chem. Soc. 141, 6362–6374 (2019)

    Article  CAS  Google Scholar 

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Acknowledgments

The research works presented in this chapter were conducted with by Prof. Hiramoto, Dr. Shintaku, Dr. Kikuchi, Mr. Lee, and Mr. Perrot in Institute for Molecular Science, and Dr. Tajima and Dr. Nakano in Riken, and Prof. Takahashi and Prof. Fujimoto in Shizuoka University. They were partly supported by the JSPS KAKENHI (Grant-in-Aid for Research Activity Start-up, No. 16H07421 and for Young Scientist, 18K14115), the foundation of Chubu Science and Technology Center and the Mazda foundation.

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  1. National Institutes of Natural Science, Institute for Molecular Science, 5-1 Higashiyama Myodaiji, Aichi, Okazaki, 444-8787, Japan

    Seiichiro Izawa

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  1. Seiichiro Izawa
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Correspondence to Seiichiro Izawa .

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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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Izawa, S. (2021). Open-Circuit Voltage in Organic Solar Cells. In: Hiramoto, M., Izawa, S. (eds) Organic Solar Cells. Springer, Singapore. https://doi.org/10.1007/978-981-15-9113-6_8

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