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Photocrosslinking of low band-gap conjugated polymers using alkyl chloride sidechains: Toward high-efficiency, thermally stable polymer solar cells

Published online by Cambridge University Press:  23 April 2018

Chi Zhang  and
Steven Holdcroft
Chi Zhang
Affiliation:
Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
Steven Holdcroft*
Affiliation:
Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
*
a)Address all correspondence to this author. e-mail: holdcrof@sfu.ca
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Abstract

We report the synthesis and photovoltaic characterization of four novel polymers based on poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl}) (PTB7) incorporating various numbers of photocrosslinkable n-octyl chloride sidechains (PTB-Cl). These polymers showed similar optoelectronic properties to PTB7 and readily cross-linked in the form of thin films after deep-UV exposure. Photolithography with micrometer-scale patterning is demonstrated. PTB-Cls exhibit similar PV performances to PTB7 and lightly cross-linked PTB-Cls showed stable high photoconversion efficiencies after prolonged thermal treatment. However, it is found that a high-degree cross-linking is needed to prevent the formation of PCBM crystallites at high annealing temperatures even though the PV performance is stabilized with a much lower degree of cross-linking. This implies that the complete prevention of PCBM crystallite formation is not necessary to affect the stabilization of PV devices against excessive heat.

Keywords

polymerphotovoltaicsolution deposition

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Type
Invited Article
Information
Journal of Materials Research , Volume 33 , Issue 13: Focus Issue: Stabilization of Organic Electronic Materials and Devices , 14 July 2018 , pp. 1879 - 1890
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Copyright © Materials Research Society 2018 

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References

REFERENCES

Espinosa, N., Hösel, M., Angmo, D., and Krebs, F.C.: Solar cells with one-day energy payback for the factories of the future. Energy Environ. Sci. 5, 5117 (2012).CrossRefGoogle Scholar
Krebs, F.: All solution roll-to-roll processed polymer solar cells free from indium-tin-oxide and vacuum coating steps. Org. Electron. 10, 761 (2009).Google Scholar
Søndergaard, R., Hösel, M., Angmo, D., Larsen-Olsen, T.T., and Krebs, F.C.: Roll-to-roll fabrication of polymer solar cells. Mater. Today 15, 36 (2012).Google Scholar
Yu, G., Gao, J., Hummelen, J.C., Wudl, F., and Heeger, A.J.: Polymer photovoltaic cells—Enhanced efficiencies via a network of internal donor-acceptor heterojunctions. Science 270, 1789 (1995).Google Scholar
Yang, X. and Loos, J.: Toward high-performance polymer solar cells: The importance of morphology control. Macromolecules 40, 1353 (2007).Google Scholar
Chen, J-T. and Hsu, C-S.: Conjugated polymer nanostructures for organic solar cell applications. Polym. Chem. 2, 2707 (2011).Google Scholar
Heeger, A.J.: 25th anniversary article: Bulk heterojunction solar cells: Understanding the mechanism of operation. Adv. Mater. 26, 10 (2014).Google Scholar
Yang, X., van Duren, J.K.J., Janssen, R.A.J., Michels, M.A.J., and Loos, J.: Morphology and thermal stability of the active layer in poly(p-phenylenevinylene)/methanofullerene plastic photovoltaic devices. Macromolecules 37, 2151 (2004).Google Scholar
Cardinaletti, I., Kesters, J., Bertho, S., Conings, B., Piersimoni, F., D’Haen, J., Lutsen, L., Nesladek, M., Van Mele, B., Van Assche, G., Vandewal, K., Salleo, A., Vanderzande, D., Maes, W., and Manca, J.V.: Toward bulk heterojunction polymer solar cells with thermally stable active layer morphology. J. Photon. Energy 4, 40997 (2014).Google Scholar
Bertho, S., Haeldermans, I., Swinnen, A., Moons, W., Martens, T., Lutsen, L., Vanderzande, D., Manca, J., Senes, A., and Bonfiglio, A.: Influence of thermal ageing on the stability of polymer bulk heterojunction solar cells. Sol. Energy Mater. Sol. Cells 91, 385 (2007).Google Scholar
Conings, B., Bertho, S., Vandewal, K., Senes, A., D’Haen, J., Manca, J., and Janssen, R.A.J.: Modeling the temperature induced degradation kinetics of the short circuit current in organic bulk heterojunction solar cells. Appl. Phys. Lett. 96, 163301 (2010).CrossRefGoogle Scholar
Lindqvist, C., Sanz-Velasco, A., Wang, E., Bäcke, O., Gustafsson, S., Olsson, E., Andersson, M.R., and Müller, C.: Nucleation-limited fullerene crystallisation in a polymer–fullerene bulk-heterojunction blend. J. Mater. Chem. A 1, 7174 (2013).Google Scholar
Bergqvist, J., Lindqvist, C., Bäcke, O., Ma, Z., Tang, Z., Tress, W., Gustafsson, S., Wang, E., Olsson, E., Andersson, M.R., Inganäs, O., and Müller, C.: Sub-glass transition annealing enhances polymer solar cell performance. J. Mater. Chem. A 2, 6146 (2014).Google Scholar
Pickett, J.E. and Sargent, J.R.: Sample temperatures during outdoor and laboratory weathering exposures. Polym. Degrad. Stab. 94, 189 (2009).Google Scholar
Haillant, O., Dumbleton, D., and Zielnik, A.: An Arrhenius approach to estimating organic photovoltaic module weathering acceleration factors. Sol. Energy Mater. Sol. Cells 95, 1889 (2011).Google Scholar
Sommer, M., Huettner, S., and Thelakkat, M.: Donor–acceptor block copolymers for photovoltaic applications. J. Mater. Chem. 20, 10788 (2010).Google Scholar
Topham, P., Parnell, A., and Hiorns, R.: Block copolymer strategies for solar cell technology. J. Polym. Sci., Part B: Polym. Phys. 49, 1131 (2011).CrossRefGoogle Scholar
Lai, Y-C., Ohshimizu, K., Takahashi, A., Hsu, J-C., Higashihara, T., Ueda, M., and Chen, W-C.: Synthesis of all-conjugated poly(3-hexylthiophene)-block-poly(3-(4′-(3″,7″-dimethyloctyloxy)-3′-pyridinyl)thiophene) and its blend for photovoltaic applications. J. Polym. Sci., Part A: Polym. Chem. 49, 2577 (2011).CrossRefGoogle Scholar
Yun, M.H., Kim, J., Yang, C., and Kim, J.Y.: A simultaneous achievement of high performance and extended thermal stability of bulk-heterojunction polymer solar cells using a polythiophene–fullerene block copolymer. Sol. Energy Mater. Sol. Cells 104, 7 (2012).Google Scholar
Lin, Y., Lim, J.A., Wei, Q., Mannsfeld, S.C.B., Briseno, A.L., and Watkins, J.J.: Cooperative assembly of hydrogen-bonded diblock copolythiophene/fullerene blends for photovoltaic devices with well-defined morphologies and enhanced stability. Chem. Mater. 24, 622 (2012).CrossRefGoogle Scholar
Bundgaard, E., Helgesen, M., Carlé, J.E., Krebs, F.C., and Jørgensen, M.: Advanced functional polymers for increasing the stability of organic photovoltaics. Macromol. Chem. Phys. 214, 1546 (2013).Google Scholar
Krebs, F.C. and Spanggaard, H.: Significant improvement of polymer solar cell stability. Chem. Mater. 17, 5235 (2005).CrossRefGoogle Scholar
Bjerring, M., Nielsen, J.S., Nielsen, N.C., and Krebs, F.C.: Polythiophene by solution processing. Macromolecules 40, 6012 (2007).Google Scholar
Brusso, J.L., Lilliedal, M.R., and Holdcroft, S.: π-Conjugated polymers with thermocleavable substituents for use as active layers in organic photovoltaics. Polym. Chem. 2, 175 (2011).Google Scholar
Vahdani, P., Li, X., Zhang, C., Holdcroft, S., and Frisken, B.J.: Morphological characterization of a new low-bandgap thermocleavable polymer showing stable photovoltaic properties. J. Mater. Chem. A 4, 10650 (2016).CrossRefGoogle Scholar
Wantz, G., Derue, L., Dautel, O., Rivaton, A., Hudhomme, P., and Dagron-Lartigau, C.: Stabilizing polymer-based bulk heterojunction solar cells via crosslinking. Polym. Int. 63, 1346 (2014).Google Scholar
Rumer, J.W. and McCulloch, I.: Organic photovoltaics: Crosslinking for optimal morphology and stability. Mater. Today 18, 425 (2015).Google Scholar
Miyanishi, S., Tajima, K., and Hashimoto, K.: Morphological stabilization of polymer photovoltaic cells by using cross-linkable poly(3-(5-hexenyl)thiophene). Macromolecules 42, 1610 (2009).CrossRefGoogle Scholar
Kim, B.J., Miyamoto, Y., Ma, B., and Fréchet, J.M.J.: Photocrosslinkable polythiophenes for efficient, thermally stable, organic photovoltaics. Adv. Funct. Mater. 19, 2273 (2009).Google Scholar
Griffini, G., Douglas, J.D., Piliego, C., Holcombe, T.W., Turri, S., Fréchet, J.M.J., and Mynar, J.L.: Long-term thermal stability of high-efficiency polymer solar cells based on photocrosslinkable donor–acceptor conjugated polymers. Adv. Mater. 23, 1660 (2011).Google Scholar
Kim, H.J., Han, A-R., Cho, C-H., Kang, H., Cho, H-H., Lee, M.Y., Fréchet, J.M.J., Oh, J.H., and Kim, B.J.: Solvent-resistant organic transistors and thermally stable organic photovoltaics based on cross-linkable conjugated polymers. Chem. Mater. 24, 215 (2012).Google Scholar
Nam, C., Qin, Y., Park, Y.S., Hlaing, H., Lu, X., Ocko, B.M., Black, C.T., and Grubbs, R.B.: Photo-cross-linkable azide-functionalized polythiophene for thermally stable bulk heterojunction solar cells. Macromolecules 45, 2338 (2012).Google Scholar
Yau, C.P., Wang, S., Treat, N.D., Fei, Z., Tremolet de Villers, B.J., Chabinyc, M.L., and Heeney, M.: Investigation of radical and cationic cross-linking in high-efficiency, low band gap solar cell polymers. Adv. Energy Mater. 5, 1401228 (2015).Google Scholar
Diacon, A., Derue, L., Lecourtier, C., Dautel, O., Wantz, G., and Hudhomme, P.: Cross-linkable azido C60-fullerene derivatives for efficient thermal stabilization of polymer bulk-heterojunction solar cells. J. Mater. Chem. C 2, 7163 (2014).CrossRefGoogle Scholar
Chen, C-P., Huang, C-Y., and Chuang, S-C.: Highly thermal stable and efficient organic photovoltaic cells with crosslinked networks appending open-cage fullerenes as additives. Adv. Funct. Mater. 25, 207 (2015).Google Scholar
Derue, L., Dautel, O., Tournebize, A., Drees, M., Pan, H., Berthumeyrie, S., Pavageau, B., Cloutet, E., Chambon, S., Hirsch, L., Rivaton, A., Hudhomme, P., Facchetti, A., and Wantz, G.: Thermal stabilisation of polymer–fullerene bulk heterojunction morphology for efficient photovoltaic solar cells. Adv. Mater. 26, 5831 (2014).CrossRefGoogle ScholarPubMed
Derue, L., Lecourtier, C., Gorisse, T., Hirsch, L., Dautel, O., and Wantz, G.: A solvent additive to enhance the efficiency and the thermal stability of polymer:fullerene solar cells. RSC Adv. 5, 3840 (2015).Google Scholar
Rumer, J.W., Ashraf, R.S., Eisenmenger, N.D., Huang, Z., Meager, I., Nielsen, C.B., Schroeder, B.C., Chabinyc, M.L., and McCulloch, I.: Dual function additives: A small molecule crosslinker for enhanced efficiency and stability in organic solar cells. Adv. Energy Mater. 5, 1401426 (2015).Google Scholar
Cheng, P., Yan, C., Lau, T-K., Mai, J., Lu, X., and Zhan, X.: Molecular lock: A versatile key to enhance efficiency and stability of organic solar cells. Adv. Mater. 28, 5822 (2016).Google Scholar
Gholamkhass, B. and Holdcroft, S.: Toward stabilization of domains in polymer bulk heterojunction films. Chem. Mater. 22, 5371 (2010).Google Scholar
Liang, Y. and Yu, L.: A new class of semiconducting polymers for bulk heterojunction solar cells with exceptionally high performance. Acc. Chem. Res. 43, 1227 (2010).Google Scholar
Liang, Y. and Yu, L.: Development of semiconducting polymers for solar energy harvesting. Polym. Rev. 50, 454 (2010).Google Scholar
Lu, L. and Yu, L.: Understanding low bandgap polymer PTB7 and optimizing polymer solar cells based on IT. Adv. Mater. 26, 4413 (2014).Google Scholar
He, Z., Zhong, C., Su, S., Xu, M., Wu, H., and Cao, Y.: Enhanced power-conversion efficiency in polymer solar cells using an inverted device structure. Nat. Photon. 6, 593 (2012).Google Scholar
Liang, Y., Xu, Z., Xia, J., Tsai, S-T., Wu, Y., Li, G., Ray, C., and Yu, L.: For the bright future-bulk heterojunction polymer solar cells with power conversion efficiency of 7.4%. Adv. Mater. 22, E135 (2010).Google Scholar
Son, H.J., Wang, W., Xu, T., Liang, Y., Wu, Y., Li, G., and Yu, L.: Synthesis of fluorinated polythienothiophene-co-benzodithiophenes and effect of fluorination on the photovoltaic properties. J. Am. Chem. Soc. 133, 1885 (2011).Google Scholar
Guo, J., Liang, Y., Szarko, J., Lee, B., Son, H.J., Rolczynski, B.S., Yu, L., and Chen, L.X.: Structure, dynamics, and power conversion efficiency correlations in a new low bandgap polymer: PCBM solar cell. J. Phys. Chem. B 114, 742 (2010).Google Scholar
Liang, Y., Feng, D., Wu, Y., Tsai, S-T., Li, G., Ray, C., and Yu, L.: Highly efficient solar cell polymers developed via fine-tuning of structural and electronic properties. J. Am. Chem. Soc. 131, 7792 (2009).Google Scholar
Pommerehne, J., Vestweber, H., Guss, W., Mahrt, R.F., Bässler, H., Porsch, M., and Daub, J.: Efficient two layer leds on a polymer blend basis. Adv. Mater. 7, 551 (1995).Google Scholar
Leclerc, M., Najari, A., and Zou, Y.: Patent No. WO 2011/063534 A1, June 9, 2011.Google Scholar
Mcmurry, J.: Organic Chemistry, 5th ed. (Brooks Cole, Pacific Grove, CA, 2000).Google Scholar
Qian, D., Xu, Q., Hou, X., Wang, F., Hou, J., and Tan, Z.: Stabilization of the film morphology in polymer: Fullerene heterojunction solar cells with photocrosslinkable bromine-functionalized low-bandgap copolymers. J. Polym. Sci., Part A: Polym. Chem. 51, 3123 (2013).Google Scholar
Chen, X., Chen, L., and Chen, Y.: The effect of photocrosslinkable groups on thermal stability of bulk heterojunction solar cells based on donor–acceptor-conjugated polymers. J. Polym. Sci., Part A: Polym. Chem. 51, 4156 (2013).Google Scholar
Ho, V., Boudouris, B.W., and Segalman, R.A.: Tuning polythiophene crystallization through systematic side chain functionalization. Macromolecules 43, 7895 (2010).Google Scholar
MacKenzie, A.R.: Chemistry and pollution of the stratosphere. In Pollution: Causes, Effects and Control, 4th ed., Harrison, R.M., ed. (Royal Society of Chemistry, Cambridge, U.K., 2001); ch. 9, pp. 220–245.Google Scholar
Abdou, M.S.A., Orfino, F.P., Son, Y., and Holdcroft, S.: Interaction of oxygen with conjugated polymers: Charge transfer complex formation with poly(3-alkylthiophenes). J. Am. Chem. Soc. 119, 4518 (1997).Google Scholar
Desiraju, G. and Steiner, T.: The Weak Hydrogen Bond: In Structural Chemistry and Biology (Oxford University Press, Oxford, England, 2001).Google Scholar
Schafferhans, J., Baumann, A., Deibel, C., and Dyakonov, V.: Trap distribution and the impact of oxygen-induced traps on the charge transport in poly(3-hexylthiophene). Appl. Phys. Lett. 93, 93303 (2008).Google Scholar
Seemann, A., Sauermann, T., Lungenschmied, C., Armbruster, O., Bauer, S., Egelhaaf, H-J., and Hauch, J.: Reversible and irreversible degradation of organic solar cell performance by oxygen. Sol. Energy 85, 1238 (2011).Google Scholar
Aygu, U., Hintz, H., Egelhaaf, H-J., Distler, A., Abb, S., Peisert, H., and Chassé, T.: Energy level alignment of a P3HT/fullerene blend during the initial steps of degradation. J. Phys. Chem. C 117, 4992 (2013).Google Scholar
Liao, H-H., Yang, C-M., Liu, C-C., Horng, S-F., Meng, H-F., and Shy, J-T.: Dynamics and reversibility of oxygen doping and de-doping for conjugated polymer. J. Appl. Phys. 103, 104506 (2008).Google Scholar
Lüer, L., Egelhaaf, H-J., Oelkrug, D., Cerullo, G., Lanzani, G., Huisman, B-H., and de Leeuw, D.M.: Oxygen-induced quenching of photoexcited states in polythiophene films. Org. Electron. 5, 83 (2004).CrossRefGoogle Scholar
Seemann, A., Egelhaaf, H-J., Brabec, C.J., and Hauch, J.A.: Influence of oxygen on semi-transparent organic solar cells with gas permeable electrodes. Org. Electron. 10, 1424 (2009).Google Scholar
Aguirre, A., Meskers, S.C.J., Janssen, R.A.J., and Egelhaaf, H-J.: Formation of metastable charges as a first step in photoinduced degradation in π-conjugated polymer:fullerene blends for photovoltaic applications. Org. Electron. 12, 1657 (2011).CrossRefGoogle Scholar
Schaffer, C.J., Palumbiny, C.M., Niedermeier, M.A., Jendrzejewski, C., Santoro, G., Roth, S.V., and Müller-Buschbaum, P.: A direct evidence of morphological degradation on a nanometer scale in polymer solar cells. Adv. Mater. 25, 6760 (2013).Google Scholar
Zhong, H., Yang, X., deWith, B., and Loos, J.: Quantitative insight into morphology evolution of thin PPV/PCBM composite films upon thermal treatment. Macromolecules 39, 218 (2006).Google Scholar
He, C., Germack, D.S., Joseph Kline, R., Delongchamp, D.M., Fischer, D.A., Snyder, C.R., Toney, M.F., Kushmerick, J.G., and Richter, L.J.: Influence of substrate on crystallization in polythiophene/fullerene blends. Sol. Energy Mater. Sol. Cells 95, 1375 (2011).Google Scholar
Yang, X., Alexeev, A., Michels, M.A.J., and Loos, J.: Effect of spatial confinement on the morphology evolution of thin poly(p-phenylenevinylene)/methanofullerene composite films. Macromolecules 38, 4289 (2005).Google Scholar
Watts, B., Belcher, W.J., Thomsen, L., Ade, H., and Dastoor, P.C.: A quantitative study of PCBM diffusion during annealing of P3HT:PCBM blend films. Macromolecules 42, 8392 (2009).Google Scholar
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