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Effects of Substituted Side Chains on the Optical and Electrical Properties of D-A Conjugated Copolymers

Published online by Cambridge University Press:  21 March 2012

Shinuk Cho*
Department of Physics, University of Ulsan, Ulsan 680-749, South Korea.
Sangkyu Lee
Energy Materials Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon 305-600, South Korea.
Minghong Tong
Center for Polymers and Organic Solids, University of California, Santa Barbara, CA 93106-5090, U.S.A.
Jung Hwa Seo
Center for Polymers and Organic Solids, University of California, Santa Barbara, CA 93106-5090, U.S.A.
Alan J. Heeger
Center for Polymers and Organic Solids, University of California, Santa Barbara, CA 93106-5090, U.S.A.
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The effects of substitute side chain were investigated using donor-acceptor (D-A) conjugated copolymers consisting of a cyclopentadithiophene (CPDT) derivative and dithienyl-benzothiadiazole (DTBT). The intrinsic properties of the copolymers were significantly altered by perturbations of the intramolecular charge transfer (ICT). The absorption of PCPDT-ttOTBTOT (P2), which assumed a tail-tail configuration, tended to blue-shift relative to the absorption of PCPDT-TBTT (P1). The absorption of PCPDT-hhOTBTOT (P3), which assumed a head-head configuration, was blue-shifted relative to that of P2. The electrical transport properties of field-effect transistors (FETs) were sensitive to the side chain position. The field-effect mobility in P2 (μ2=1.8×10–3 cm2/V·s) was slightly lower that in P1 (μ1=4.9×10–3 cm2/V·s). The mobility of P3, however, was very low (μ3=3.8×10–6 cm2/V·s). Photoexcitation spectroscopy showed that the charge generation efficiency (shown in transient absorption spectra) and polaron pair mobility in P1 and P2 were higher than in P3, yielding P1 and P2 device performances that were better than the performance of devices based on P3.

Copyright © Materials Research Society 2012

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[1] Svensson, M., Zhang, F., Veenstra, S. C., Verhees, W. J. H., Hummelen, J. C., Kroon, J. M., Inganäs, O., and Andersson, M. R., Adv. Mater. 15, 988991 (2003).CrossRefGoogle Scholar
[2] Blouin, N., Michaud, A., Gendron, D., Wakim, S., Blair, E., Neagu-Plesu, R., Belletête, M., Durocher, G., Tao, Y., and Leclerc, M., J. Am. Chem. Soc. 130, 732742 (2008).CrossRefGoogle Scholar
[3] Blouin, N., Michaud, A., Leclerc, M., Adv. Mater. 19, 22952300 (2007).CrossRefGoogle Scholar
[4] Scharber, M. C., Mühlbacher, D., Koppe, M., Denk, P., Waldauf, C., Heeger, A. J., and Brabec, C. J., Adv. Mater. 18, 789794 (2006).CrossRefGoogle Scholar
[5] Wang, E., Wang, L., Lan, L., Luo, C., Zhuang, W., Peng, J., and Cao, Y., Appl. Phys. Lett. 92, 033307 (2008).CrossRefGoogle Scholar
[6] Kline, R. J., McGehee, M. D., Kadnikova, E. N., Liu, J., and Fréchet, J. M. J., Adv. Mater. 15, 15191522 (2003).CrossRefGoogle Scholar
[7] Zen, A., Pfluam, J., Hirschmann, S., Zhuang, W., Jaiser, F., Asawapirom, U., Rabe, J. P., Schref, U., and Neher, D., Adv. Funct. Mater. 14, 757764 (2004).CrossRefGoogle Scholar
[8] Roncali, J., Macromol. Rapid Commun. 28, 17611775 (2007).CrossRefGoogle Scholar
[9] Jayakannan, M., Van Hal, P. A., and Janssen, R. A. J., J. Poly. Sci. A Polym. Chem. 40, 251261 (2002).CrossRefGoogle Scholar
[10] Gadisa, A., Mammo, W., Andersson, L. M., Admassie, S., Zhang, F., Andersson, M. R., and Inganäs, O., Adv. Funct. Mater. 17, 3836 (2007).CrossRefGoogle Scholar
[11] Jespersen, K. G., Beenken, W. J. D., Zaushitsyn, Y., Yartsev, A., Andersson, M., Pullerits, T., and Sundström, V., J. Chem. Phys. 121, 12613 (2004).CrossRefGoogle Scholar
[12] Perzon, E., Wang, X., Admassie, S., Inganäs, O., and Andersson, M. R., Polymer 47, 4261 (2006).CrossRefGoogle Scholar