On the origin of the open-circuit voltage of polymer-fullerene solar cells

Nature Materials

Volumn 8, Issue 11, 2009, Pages 904-909

  Vandewal, Koen ^a   Tvingstedt, Kristofer ^b   Gadisa, Abay ^a   Inganäs, Olle ^b   Manca, Jean V ^a  

^a HASSELT UNIVERSITY   (Belgium)

^b LINKÖPING UNIVERSITY   (Sweden)

Author keywords

[No Author keywords available]

Indexed keywords

CHARGE TRANSFER; CONJUGATED POLYMERS; EFFICIENCY; FULLERENES; GROUND STATE; HETEROJUNCTIONS; OPEN CIRCUIT VOLTAGE; ORGANIC POLYMERS; ORGANIC SOLAR CELLS; PHOTOVOLTAIC CELLS; POLYMER SOLAR CELLS; TIMING CIRCUITS;

BULK HETEROJUNCTION; CHARGE-TRANSFER ABSORPTION; GROUND-STATE INTERACTIONS; OVERALL EFFICIENCY; OVERALL POWER CONVERSION EFFICIENCY; PHOTOVOLTAIC SYSTEMS; POLYMER-FULLERENE; SOLUTION PROCESSABLE;

SOLAR CELLS;

FULLERENE DERIVATIVE; ORGANIC COMPOUND; POLYMER;

ARTICLE; CHEMISTRY; ELECTROCHEMISTRY; PHOTOCHEMISTRY; SURFACE PROPERTY;

ELECTROCHEMISTRY; FULLERENES; ORGANIC CHEMICALS; PHOTOCHEMISTRY; POLYMERS; SURFACE PROPERTIES;

EID: 70350572328     PISSN: 14761122     EISSN: 14764660     Source Type: Journal    
DOI: 10.1038/nmat2548     Document Type: Article

References (42)

1. Thompson, B. C. & Fréchet, J. M. J. Polymer-fullerene composite solar cells. Angew. Chem. Int. Ed. 47, 58-77 (2008).
2. Park, S. H. et al. Bulk heterojunction solar cells with internal quantum efficiency approaching 100%. Nature Photon. 3, 297-302 (2009).
3. Dennler, G., Scharber, M. C. & Brabec, C. J. Polymer-fullerene bulk-heterojunction solar cells. Adv. Mater. 13, 1323-1338 (2009).
4. Scharber, M. C. et al. Design rules for donors in bulk-heterojunction solar cells-towards 10% energy-conversion efficiency. Adv. Mater. 18, 789-794 (2006).
5. Veldman, D., Meskers, S. C. J. & Janssen, R. A. J. 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).
6. Shockley, W. & Queisser, H. Detailed balance limit of efficiency of p-n junction solar cells. J. Appl. Phys. 32, 510-519 (1961).
7. Gadisa, A., Svensson, M., Andersson, M. R. & Inganäs, O. Correlation between oxidation potential and open-circuit voltage of composite solar cells based on blends of polythiophenes/fullerene derivative. Appl. Phys. Lett. 84, 1609-1611 (2004).
8. Nelson, J., Kirkpatrick, J. & Ravirajan, P. Factors limiting the efficiency of molecular photovoltaic devices. Phys. Rev. B 69, 035337 (2004).
9. Rand, B. P., Burk,D. P. & Forrest, S. R. Offset energies at organic semiconductor heterojunctions and their influence on the open-circuit voltage of thin-film solar cells. Phys. Rev. B 75, 115327 (2007).
10. Potscavage, W. J., Yoo, S. & Kippelen, B. Origin of the open-circuit voltage in multilayer heterojunction organic solar cells. Appl. Phys. Lett. 93, 193308 (2008).
11. Kirchartz, T., Mattheis, J. & Rau, U. Detailed balance theory of excitonic and bulk heterojunction solar cells. Phys. Rev. B 78, 235320 (2008).
12. Benson-Smith, J. J. et al. Formation of a ground-state charge-transfer complex in polyfluorene/[6,6]-phenyl-C-61 butyric acid methyl ester (PCBM) blend films and its role in the function of polymer/PCBM solar cells. Adv. Funct. Mater. 17, 451-457 (2007).
13. Loi, M. A. et al. Charge transfer excitons in bulk heterojunctions of a polyfluorene copolymer and a fullerene derivative. Adv. Funct. Mater. 17, 2111-2116 (2007).
14. Hallermann, M., Haneder, S. & Da Como, E. Charge-transfer states in conjugated polymer/fullerene blends: Below-gap weakly bound excitons for polymer photovoltaics. Appl. Phys. Lett. 93, 053307 (2008).
15. 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).
16. Kim, H. et al. Electroluminescence in polymer-fullerene photovoltaic cells. Appl. Phys. Lett. 86, 183502 (2005).
17. Tvingstedt, K. et al. Electroluminescence from charge transfer states in polymer solar cells. J. Am. Chem. Soc. 131, 11819-11824 (2009).
18. Goris, L. et al. Absorption phenomena in organic thin films for solar cell applications investigated by photothermal deflection spectroscopy. J. Mater. Sci. 40, 1413-1418 (2005).
19. Goris, L. et al. Observation of the subgap optical absorption in polymer-fullerene blend solar cells. Appl. Phys. Lett. 88, 052113 (2006).
20. Vandewal, K. et al. The relation between open-circuit voltage and the onset of photocurrent generation by charge-transfer absorption in polymer: fullerene bulk heterojunction solar cells. Adv. Funct. Mater. 18, 2064-2070 (2008).
21. Campoy-Quiles, M. et al. Morphology evolution via self-organization and lateral and vertical diffusion in polymer: fullerene solar cell blends. Nature Mater. 7, 158-164 (2008).
22. Ma, W. L., Yang, C. Y., Gong, X., Lee, K. & Heeger, A. J. Thermally stable, efficient polymer solar cells with nanoscale control of the interpenetrating network morphology. Adv. Funct. Mater. 15, 1617-1622 (2005).
23. Peet, J. et al. Efficiency enhancement in low-bandgap polymer solar cells by processing with alkane dithiols. Nature Mater. 6, 497-500 (2007).
24. Wienk, M. M. et al. Efficient methano[70]fullerene/MDMO-PPV bulk heterojunction photovoltaic cells. Angew. Chem. Int. Ed. 42, 3371-3375 (2003).
25. Vanecek, M. & Poruba, A. Fourier-transform photocurrent spectroscopy of microcrystalline silicon for solar cells. Appl. Phys. Lett. 80, 719-721 (2002).
26. Würfel, P. The chemical potential of radiation. J. Phys. C 15, 3967-3985 (1982).
27. Schick, K., Daub, E., Finkbeiner, S. & Würfel, P. Verification of a generalized Planck law for luminescence radiation from silicon solar cells. Appl. Phys. A 54, 109-114 (1992).
28. Trupke, T., Würfel, P., Uhlendorf, I. & Lauermann, I. Electroluminescence of the dye-sensitized solar cell. J. Phys. Chem. B 103, 1905-1910 (1999).
29. Band, Y. B. & Heller, D. F. Relationships between absorption and emission of light in multilevel systems. Phys. Rev. A 38, 1885-1895 (1988).
30. Ross, R. T. & Calvin, M. Thermodynamics of light emission and free-energy storage in photosynthesis. Biophys. J. 7, 595-614 (1967).
31. Green, M. A. Third Generation Photovoltaics: Advanced Solar Energy Conversion (Springer, 2006).
32. Rau, U. Reciprocity relation between photovoltaic quantum efficiency and electroluminescent emission of solar cells. Phys. Rev. B 76, 085303 (2007).
33. Kirchartz, T. & Rau, U. Detailed balance and reciprocity in solar cells. Phys. Status Solidi A 205, 2737-2751 (2008).
34. Bruan, D. Electron injection and conduction processes for polymer devices. J. Polym. Sci. Part B: Polym. Phys. 41, 2622-2629 (2003).
35. Waldauf, C., Scharber, M. C., Schilinsky, P., Hauch, J. A. & Brabec, C. J. Physics of organic bulk heterojunction devices for photovoltaic applications. J. Appl. Phys. 99, 104503 (2006).
36. Panda, P. et al. Charge transfer absorption for pi-conjugated polymers and oligomers mixed with electron acceptors. J. Phys. Chem. B 111, 5076-5081 (2007).
37. Foster, R. Organic Charge-Transfer Complexes (Academic, 1969).
38. Pope, M. & Swenberg, C. E. Electronic Processes in Organic Crystals and Polymers (Oxford Univ. Press, 1999).
39. Ross, R. B. et al. Endohedral fullerenes for organic photovoltaic devices. Nature Mater. 8, 208-212 (2009).
40. Lenes, M. et al. Fullerene bisadducts for enhanced open-circuit voltages and efficiencies in polymer solar cells. Adv. Mater 20, 2116-2119 (2008).
41. Zhang, F. et al. High photovoltage achieved in low band gap polymer solar cells by adjusting energy levels of a polymer with the LUMOs of fullerene derivatives. J. Mater. Chem. 18, 5468-5474 (2008).
42. Perez, M. D., Borek, C., Forrest, S. R. & Thompson, M. E. Molecular and morphological influences on the open circuit voltages of organic photovoltaic devices. J. Am. Chem. Soc. 131, 9281 (2009).