Theoretical Study on Electronic Structure and Photophysical Properties of Low Band Gap Dithiophene Copolymer with Different Bridging Atoms

Abstract

Abstract: The excited state characteristics of two low band gap donor-accepter copolymers with different bridging atoms used in bulk heterojunction solar cells were analyzed through their absorption spectra. The charge transfer state (CT) features were investigated to distinguish their abilities of charge separations. The electronic structures and spectral properties of PSBTBT and PCPDTBT (n = 1 ~ 4) have been investigated based on density functional theory (DFT) and time-dependent density functional theory (TD-DFT). The results show that the absorption spectrum of PSBTBT is similar to that of PCPDTBT and they have similar abilities to match with the solar spectra. Meanwhile, their capabilities of charge separations for the charge transfer state (CT) are similar to each other in terms of exciton binding energy. However, when the carbon atom was replaced by the silicon atom in the main chain of the conjugated polymer, the C-Si bond is significantly longer than the C-C bond, which reduces the steric hindrance between the alkyl groups and the thiophene ring. Thus this replacement may be beneficial to the improvement of the crystallinity and increment of the carrier transport ability. These results indicate that PSBTBT may be a promising polymer material for application in polymer solar cells.

Key words: Dithiophene, Low band gap, Solar cells, Photophysical properties, Density functional theory

CLC Number:

O641

TrendMD:

DUAN Yu-Ai, GENG Yun, LI Hai-Bin, YANG Guo-Chun, WU Shui-Xing, HAO Li-Zhu, LIAO Yi*, SU Zhong-Min*. Theoretical Study on Electronic Structure and Photophysical Properties of Low Band Gap Dithiophene Copolymer with Different Bridging Atoms[J]. Chem. J. Chinese Universities, 2011, 32(4): 920.

References

[1] Yu, Y. H., Kamat, P. V., Kuno, M., et al., Adv. Funct. Mater. [J], 2010, 20: 1464-1472. [2] Grinis, L., Kotlyar, S., Ruhle, S., et al., Adv. Funct. Mater. [J], 2010, 20: 282-288. [3] Sung, C. F., Kekuda, D., Chu, L. F., et al., Adv. Mater. [J], 2010, 21: 4845-4849. [4] Lu, X. J., Mou, X. L., Wu, J. J., et al., Adv. Funct. Mater. [J], 2010, 20: 509-515. [5] Zheng, Q. D., Jung, B. J., Sun, J., et al., J. Am. Chem. Soc. [J], 2010, 132: 5394-5404. [6] Solarmer Energy, Inc. Breaks Psychological Barrier with 8.13% OPV Efficiency, http://www.forbes.com/feeds/businesswire/2010/07/27/businesswire142993163.html, (last visited Sept. 6, 2010). [7] Lewis, N. S., Science [J], 2007, 315: 798-801. [8] Thompson, Barry C., Fréchet, Jean M. J., et al., Angew. Chem. Int. Ed. [J], 2008, 47: 58-77. [9] Brabec, C. J., Sariciftci, N. S., Hummelen, J. C., et al., Adv. Funct. Mater. [J], 2001, 11: 15-26. [10] Qin, R. P., Li, W. W., Li, C. H., et al., J. Am. Chem. Soc. [J], 2009, 131: 14612-14613. [11] Mayer, A. C., Scully, S. R., Hardin, B. E., et al., Mater. Today [J], 2007, 10: 28-33. [12] Huo, L. J., Hou, J. H., Zhang, S. Q., et al., Angew. Chem.,Int. Ed. Engl. [J], 2010, 49: 1500-1503. [13] Liang, Y., Xu, Z., Xia, J., et al., Adv. Mater. [J], 2010, 22: E135-E138. [14] Park, S. H., Roy, A., Beaupre, S., et al., Nat. Photon. [J], 2009, 3: 297-302. [15] Coffin, R. C., Peet, J., Rogers, J., et al., Nat. Chem. [J], 2009, 1: 657-661. [16] Scharber, M. C., Wuhlbacher, D., Koppe, M., et al., Adv. Mater. [J], 2006, 18: 789-794. [17] Walker, B., Tomayo, A. B., Dang, X. D., et al., Adv. Funct. Mater. [J], 2009, 19: 3063-3069. [18] Koster, L. J. A., Mihailetchi, V. D., Blom, P. W. M., et al., Appl. Phys. Lett. [J], 2006, 88: 093511-093511-3 [19] Koppe, M., Egelhaaf, H. J., Dennler, G., et al., Adv. Funct. Mater. [J], 2010, 20: 338-346. [20] Yu, G., Gao, J., Hummelen, J. C., et al., Science [J], 1995, 270: 1789-1791. [21] Hou, J. H., Chen, H. Y., Zhang, S. Q., et al., J. Am. Chem. Soc. [J], 2008, 130: 16144-16145. [22] Zhu, Z., Waller, D., Gaudiana, R., et al., Macromolecules [J], 2007, 40: 1981-1986. [23] Morana, M., Azimi, H., Dennler, G., et al., Adv. Funct. Mater. [J], 2010, 20: 1180-1188. [24] Scharber, M. C., Koppe, M., Gao, J., et al., Adv. Mater. [J], 2010, 22: 367-370. [25] Chen, H. Y., Hou, J., Hayden, A. E., et al., Adv. Mater. [J], 2010, 22: 371-375. [26] Mühlbacher, D., Scharber, M., Morana, M., et al., Adv. Mater. [J], 2006, 18: 2884-2889. [27] Peet, J., Kim, J. Y., Coates, N. E., et al., Nat Mater [J], 2007, 6: 497-500. [28]Huo, L. J., Chen, H. Y., Hou, J. H., et al., Chem. Comm. [J], 2009, 5570-5572. [29] Frisch M. J., Trucks G. W. , Schlegel H. B. , et al , Gaussian 09, Revision A.02, Gaussian, Inc.: Wallingford, CT, 2009 [30] Shi, L. L., Liao, Y., Yang, G. C., et al., Inorg. Chem. [J], 2008, 47: 2347-2355. [31] Friedel, B., McNeill, C. R., Greenham, N. C., et al., Chem. Mater. [J], 2010, 22: 3389-3398. [32] Cadisa, A., Oosterbaan, W. D., Vandewal, K., et al., Adv. Funct. Mater. [J], 2009, 19: 3300-3306. [33] Gorelsky, S. I., AOMix: Program for Molecular Orbital Analysis York University: Toronto http://www.sg-chem.net/:, 1997 [34] Gorelsky, S. I., Lever, A. B. P., et al., J. Organomet. Chem. [J], 2001, 635: 187-196. [35] Valeev, E. F., Coropceanu, V., Da Silva Filho, D. A., et al., J. Am. Chem. Soc. [J], 2006, 128: 9882-9886. [36] Schmidt, R., Oh, J. H., Sun, Y. S., et al., J. Am. Chem. Soc. [J], 2009, 131: 6215-6228. [37] Ren, X. F., Ren, A. M., Zou, L. Y., et al., Theo. Chem. Acc. [J], 2010, 126: 305-314. [38] Shi, L. L., Li, T., Zhao, S. S., et al., Theo. Chem. Acc. [J], 2009, 124: 29-36. [39] Kan, Y. H., Yang, G. C., Yang, S. Y., et al., Chem. Phys. Lett. [J], 2006, 418: 302-306. [40] Wu, J., Wu, S., Geng, Y., et al., Theo. Chem. Acc. [J], 2010, DOI: 10.1007/s00214. [41] Liao, Y., Yang, G. C., Feng, J. K., et al., J. Phys. Chem. A [J], 2006, 110: 13036-13044. [42] Zhou, Y., Tvingstedt, K., Zhang, F. L., et al., Adv. Funct. Mater. [J], 2009, 19: 3293-3299. [43] Hellstrom, S., Zhang, F. L., Inganas, O., et al., Dalton. Trans. [J], 2009, 10032-10039. [44] CHANG Qing(常青), WU Shui-Xing(吴水星), Kan Yu-He(阚玉和), et al., Chem. J. Chinese Universities(高等学校化学学报)[J], 2008, 29：1011-1015 [45] Yang, L., Feng, J. K., Liao, Y., et al., Opt. Mater. [J], 2007, 29: 642-650. [46] Bijleveld, J. C., Shahid, M., Gilot, J., et al., Adv. Funct. Mater. [J], 2009, 19: 3262-3270. [47] Blouin, N., Michaud, A., Gendron, D., et al., J. Am. Chem. Soc. [J], 2008, 130: 732-742. [48] Salassa, L., Garino, C., Salassa, G., et al., J. Am. Chem. Soc. [J], 2008, 130: 9590-9597. [49] Ran, X.Q., Feng, J.K., Ren, A.M., et al., J. Phys. Chem. A. [J], 2009, 113: 7933-7939. [50] TANG Xiao-Dan(汤肖丹), GAO Hong-Ze(高洪泽)., GENG Yun(耿允), et al., Chem. J. Chinese Universities(高等化学学报) [J], 2010, 31: 766-771.