物理化学学报 >> 2015, Vol. 31 >> Issue (5): 866-876.doi: 10.3866/PKU.WHXB201503254

理论与计算化学 上一篇    下一篇

半菁染料作为染料敏化太阳能电池吸光材料的理论研究

李会学1, 左国防1, 李志锋1, 王晓峰1, 郑仁慧2   

  1. 1 天水师范学院化学工程与技术学院, 甘肃天水741001;
    2 中国科学院化学研究所分子动态与稳态结构国家重点实验室, 北京100190
  • 收稿日期:2015-02-27 修回日期:2015-03-25 发布日期:2015-05-08
  • 通讯作者: 李会学 E-mail:li_hx2001@126.com
  • 基金资助:

    国家自然科学基金(21465021, 21463023), 教育部重点项目(211189), 甘肃省自然科学基金(1208RJZE139)和甘肃省高校领军人才项目(11zx-04)资助

Theoretical Study of Hemicyanine Dye as a Dye-Sensitized Solar Cell Light-Absorbing Material

LI Hui-Xue1, ZUO Guo-Fang1, LI Zhi-Feng1, WANG Xiao-Feng1, ZHENG Ren-Hui2   

  1. 1 College of Chemical Engineering and Technology, Tianshui Normal University, Tianshui 741001, Gansu Province, P. R. China;
    2 State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
  • Received:2015-02-27 Revised:2015-03-25 Published:2015-05-08
  • Contact: LI Hui-Xue E-mail:li_hx2001@126.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21465021, 21463023), Key Project of Ministry of Education, China (211189), Natural Science Foundation of Gansu Province, China (1208RJZE139), and Program of Gansu Provincial University for Leaders of Disciplines in Science, China (11zx-04).

摘要:

采用第一性原理研究了半菁-二氧化钛团簇形成的配合物(hemicyanine-(TiO2)n)的光电子转移过程, 这里n分别取5, 9, 15. 配合物基态构型采用密度泛函理论方法进行优化, 而激发态采用含时密度泛函理论进行计算. 采用长程相关校正的密度泛函CAM-B3LYP和ωB97X-D计算的激发能与实验值吻合得很好. 依据广义Mulliken-Hush (GMH)公式, 基于密度泛函理论得到的波函数被用来计算电荷转移积分, 进而可根据Marcus理论计算出电荷分离速率常数(kCS)和电荷回传速率常数(kCR). 计算结果表明电子从染料到(TiO2)n团簇的传递有多条通道, 这使得kCS具有更大值, 相反, 只具有单通道的电荷回传降低了kCR值, 与kCS相比甚至可以忽略, 这表明在所研究的体系中电荷回传是不利的.

关键词: 理论研究, 半菁染料, (TiO2)n团簇, 电子转移

Abstract:

We used first-principles calculations to investigate the photo-induced electron transfer (PIET) process of the hemicyanine-(TiO2)n complex ((TiO2)n-dye) for n=5, 9, 15. The geometries of the (TiO2)n-dye in the ground state were optimized using density functional theory (DFT) and their excited states were investigated using the time-dependent DFT (TDDFT) method. The excited energies, which were calculated using the longrange- corrected functionals, CAM-B3LYP and ωB97X-D, were in good agreement with the experimentally observed values. The wave functions based on DFT were used to calculate the charge transfer integrals by the generalized Mulliken-Hush (GMH) approach. In addition, the photo-induced charge separation rate constant (kCS) and charge recombination rate constant (kCR) were calculated using Marcus theory. The calculated results showed that there were a cascade of electron transfer channels from the dye into the (TiO2)n cluster, which increases the kCS value. In contrast, the single channel of charge recombination decreases the kCR value, which is negligible compared with kCS, indicating that electron recombination is not favored.

Key words: Theoretical study, Hemicyanine dye, (TiO2)n cluster, Electron transfer

MSC2000: 

  • O641