Abstract
Polymer solar cells are an exciting class of next-generation photovoltaics, because they hold promise for the realization of mechanically flexible, lightweight, large-area devices that can be fabricated by room-temperature solution processing1,2. High power conversion efficiencies of ∼10% have already been reported in tandem polymer solar cells3. Here, we report that similar efficiencies are achievable in single-junction devices by reducing the tail state density below the conduction band of the electron acceptor in a high-performance photoactive layer made from a newly developed semiconducting polymer with a deepened valence energy level. Control over band tailing is realized through changes in the composition of the active layer and the structure order of the blend, both of which are known to be important factors in cell operation4,5,6. The approach yields cells with high power conversion efficiencies (∼9.94% certified) and enhanced photovoltage.
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References
Li, G., Zhu, R. & Yang, Y. Polymer solar cells. Nature Photon. 6, 153–161 (2012).
Li, Y. F. Molecular design of photovoltaic materials for polymer solar cells: toward suitable electronic energy levels and broad absorption. Acc. Chem. Res. 45, 723–733 (2012).
You, J. et al. A polymer tandem solar cell with 10.6% power conversion efficiency. Nature Commun. 4, 1446 (2013).
Blakesley, J. C. & Neher, D. Relationship between energetic disorder and open-circuit voltage in bulk heterojunction organic solar cells. Phys. Rev. B 84, 075210 (2011).
Garcia-Belmonte, G. & Bisquert, J. Open-circuit voltage limit caused by recombination through tail states in bulk heterojunction polymer–fullerene solar cells. Appl. Phys. Lett. 96, 113301 (2010).
Thakur, A. K., Wantz, G., Garcia-Belmonte, G., Bisquert, J. & Hirsch, L. Temperature dependence of open-circuit voltage and recombination processes in polymer–fullerene based solar cells. Sol. Energy Mater. Sol. Cells 95, 2131–2135 (2011).
He, Z. C. et al. Enhanced power-conversion efficiency in polymer solar cells using an inverted device structure. Nature Photon. 6, 591–595 (2012).
Liao, S. H., Jhuo, H. J., Cheng, Y. S. & Chen, S. A. 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).
Liu, Y. et al. Aggregation and morphology control enables multiple cases of high-efficiency polymer solar cells. Nature Commun. 5, 6293 (2014).
Liang, Y. Y. et al. For the bright future—bulk heterojunction polymer solar cells with power conversion efficiency of 7.4%. Adv. Mater. 22, E135–E138 (2010).
Li, W. W., Furlan, A., Hendriks, K. H., Wienk, M. M. & Janssen, R. A. Efficient tandem and triple-junction polymer solar cells. J. Am. Soc. Chem. 135, 5529–5532 (2013).
Brabec, C. J. et al. Origin of the open circuit voltage of plastic solar cells. Adv. Funct. Mater. 11, 374–380 (2001).
Blom, P. W. M., Mihailetchi, V. D., Koster, L. J. A. & Markov, D. E. Device physics of polymer:fullerene bulk heterojunction solar cells. Adv. Mater. 19, 1551–1566 (2007).
Vandewal, K., Tvingstedt, K., Gadisa, A., Inganäs, O. & Manca, J. V. On the origin of the open-circuit voltage of polymer–fullerene solar cells. Nature Mater. 8, 904–909 (2009).
Veldman, D. et al. Compositional and electric field dependence of the dissociation of charge transfer excitons in alternating polyfluorene copolymer/fullerene blends. J. Am. Chem. Soc. 130, 7721–7735 (2008).
Zhang, M., Wang, H., Tian, H., Geng, Y. & Tang, C. W. Bulk heterojunction photovoltaic cells with low donor concentration. Adv. Mater. 23, 4960–4964 (2011).
Yang, B. et al. Solution-processed fullerene-based organic Schottky junction devices for large-open-circuit-voltage organic solar cells. Adv. Mater. 25, 572–577 (2013).
Cowan, S. R., Roy, A. & Heeger, A. J. Recombination in polymer–fullerene bulk heterojunction solar cells. Phys. Rev. B 82, 245207 (2010).
Boix, P. P., Guerrero, A., Marchesi, L. F., Garcia-Belmonte, G. & Bisquert, J. Current–voltage characteristics of bulk heterojunction organic solar cells: connection between light and dark curves. Adv. Energy Mater. 1, 1073–1078 (2011).
Maurano, A. et al. Recombination dynamics as a key determinant of open circuit voltage in organic bulk heterojunction solar cells: a comparison of four different donor polymers. Adv. Mater. 22, 4987–4992 (2010).
Hawks, S. A. et al. Relating recombination, density of states, and device performance in an efficient polymer:fullerene organic solar cell blend. Adv. Energy Mater. 3, 1201–1209 (2013).
Guerrero, A. et al. Charge carrier transport and contact selectivity limit the operation of PTB7-based organic solar cells of varying active layer thickness. J. Mater. Chem. A 1, 12345–12354 (2013).
Guerrero, A. et al. How the charge-neutrality level of interface states controls energy level alignment in cathode contacts of organic bulk-heterojunction solar cells. ACS Nano 6, 3453–3460 (2011).
Koster, L. J. A., Mihailetchi, V. D., Ramaker, R. & Blom, P. W. M. Light intensity dependence of open-circuit voltage of polymer:fullerene solar cells. Appl. Phys. Lett. 86, 123509 (2005).
Garcia-Belmonte, G. et al. Influence of the intermediate density-of-states occupancy on open-circuit voltage of bulk heterojunction solar cells with different fullerene acceptors. J. Phys. Chem. Lett. 1, 2566–2571 (2010).
Ripolles, T. S., Guerrero, A. & Garcia-Belmonte, G. Polymer defect states modulate open-circuit voltage in bulk-heterojunction solar cells. Appl. Phys. Lett. 103, 243306 (2013).
Street, R. A. & Schoendorf, M. Interface state recombination in organic solar cells. Phys. Rev. B 81, 205307 (2010).
Nayak, P. K., Garcia-Belmonte, G., Kahn, A., Bisquert, J. & Cahen, D. Photovoltaic efficiency limits and material disorder. Energy Environ. Sci. 5, 6022–6039 (2012).
Liu, F. et al. Understanding the morphology of PTB7:PCBM blends in organic photovoltaics. Adv. Energy Mater. 4, 1301377 (2014).
Ma, W. et al. Domain purity, miscibility, and molecular orientation at donor/acceptor interfaces in high performance organic solar cells: paths to further improvement. Adv. Energy Mater. 3, 864–872 (2013).
Acknowledgements
The authors thank M. Yun and X. Wang for device performance verification. H.W., Z.H. and Y.C. thank the National Nature Science Foundation of China (nos. 51225301, 51403066, 91333206 and 51010003), the Fundamental Research Funds for the Central Universities (2014ZM001) and the Ministry of Science and Technology of China (2014CB643500) for financial support. F.L. and T.P.R. thank Polymer-Based Materials for Harvesting Solar Energy (PHaSE), an Energy Frontier Research Center funded by the US Department of Energy, Office of Basic Energy Sciences (DE-SC0001087), for support. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under contract no. DE-AC02-05CH11231.
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H.W., Z.H. and B.X. conceived the idea and designed the experiments. Z.H. fabricated and characterized the devices. F.L., C.W. and T.P.R. conducted structure characterizations. Y.Y. and S.X. synthesized the electron donor. H.W. and Y.C. coordinated and directed the study. All authors contributed to manuscript preparation, data analysis and interpretation, and discussed the results.
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He, Z., Xiao, B., Liu, F. et al. Single-junction polymer solar cells with high efficiency and photovoltage. Nature Photon 9, 174–179 (2015). https://doi.org/10.1038/nphoton.2015.6
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DOI: https://doi.org/10.1038/nphoton.2015.6
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