Acta Chim. Sinica ›› 2016, Vol. 74 ›› Issue (3): 251-258.DOI: 10.6023/A15090606 Previous Articles     Next Articles



赵蔡斌a, 王占领b, 周科a, 葛红光a, 张强a, 靳玲侠a, 王文亮c, 尹世伟c   

  1. a. 陕西理工学院化学与环境科学学院 汉中 723000;
    b. 陕西理工学院机械工程学院 汉中 723000;
    c. 陕西省大分子科学重点实验室 陕西师范大学化学化工学院 西安 710062
  • 投稿日期:2015-09-15 发布日期:2015-11-24
  • 通讯作者: 赵蔡斌
  • 基金资助:

    项目受国家自然科学基金(No. 21373132)和陕西理工学院博士科研启动基金(Nos. SLGKYQD2-13, SLGKYQD2-10, SLGQD14-10)资助.

Theoretical Investigation on Photovoltaic Properties of BDT and DPP Copolymer as a Promising Organic Solar Cell

Zhao Caibina, Wang Zhanlingb, Zhou Kea, Ge Hongguanga, Zhang Qianga, Jin Lingxiaa, Wang Wenliangc, Yin Shiweic   

  1. a School of Chemistry and Environment Science, Shaanxi University of Technology, Hanzhong 723000;
    b School of Mechanical Engineering, Shaanxi University of Technology, Hanzhong 723000;
    c Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062
  • Received:2015-09-15 Published:2015-11-24
  • Supported by:

    Project supported by the National Natural Science Foundation of China (No. 21373132) and the Doctor Research start foundation of Shaanxi University of Technology (Nos. SLGKYQD2-13, SLGKYQD2-10, SLGQD14-10).

Designing and synthesizing novel polymer electron-donor materials of polymer-based solar cells (PSCs) with the high photovoltaic performance is an important and hot research field of organic electronics. In the current work, taking the 4,8-di(thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene (DBDT) as the electron-rich unit and the 3,6-di(thiophen-2-yl)pyrrolo[3, 4-c]pyrrole-1,4(2H,5H)-dione (DPP) as the electron-deficient one, a new donor material (PDBDTDPP) of PSCs has been designed. Then, with the [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) as an electron acceptor, the geometries, electronic properties, optical absorption properties, intramolecular and intermolecular reorganization energies, exciton binding energies, charge transfer integrals, and the rates of exciton dissociation and charge recombination for PC61BM-DBDTDPPn=1,2,3,∞ systems have been theoretically investigated by means of density functional theory (DFT) calculations coupled with the incoherent Marcus-Hush charge transfer model and some extensive multidimensional visualization techniques. In addition, the linear regression analysis has been done to explore the relationship between the above properties and the repeating unit. Calculated results show that the designed donor polymer possesses a good planar geometry, the low-lying the highest occupied molecular orbital (HOMO) level, strong and wide optical absorption in ultraviolet-visible band, large exciton binding energy (1.365 eV), and the relatively small intramolecular reorganization energies companying with the exciton dissociation (0.152 eV) and charge recombination (0.314 eV) processes. Furthermore, our theoretical study also reveals that in the donor-acceptor surface, the exciton dissociation rate is as high as 1.073×1014 s-1, while the charge recombination rate is only 1.797×108 s-1. The former is as six orders of magnitude large as the latter, which denotes that there is quite high exciton dissociation efficiency in the studied donor-acceptor surface. In brief, our theoretical results clearly indicate that PDBDTDPP should be a very promising electron-donating material, and is worth of making further device research by experiments. In addition, this study also shows that theoretical investigations not only can promote a deeper understanding for the connection between the chemical structures and the optical/electronic properties of organic compounds, but also can provide some valuable references for the rational design of novel donor-acceptor systems.

Key words: polymer-based solar cells, benzo[1,2-b:4,5-b']dithiophene, 3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H, 5H)-dione, exciton dissociation, charge recombination