Theoretical Study of Hemicyanine Dye as a Dye-Sensitized Solar Cell Light-Absorbing Material
Theoretical Study of Hemicyanine Dye as a Dye-Sensitized Solar Cell Light-Absorbing Material
复制标题
半花青染料作为染料敏化太阳能电池吸光材料的理论研究
DOI：
10.3866/pku.whxb201503254
复制
发表时间：
2015-05
期刊：
影响因子：
--
通讯作者：
Zheng Ren-Hui
中科院分区：
文献类型：
--
作者：
Li Hui-Xue;Zuo Guo-Fang;Li Zhi-Feng;Wang Xiao-Feng;Zheng Ren-Hui
用第一性原理计算方法研究了n=5、9、15的半花菁-(二氧化钛)(N)、络合物((二氧化钛)(N)-染料)的光致电子转移(PIET)过程。用密度泛函理论(DFT)优化了(TiO2)(N)-染料的基态构型，并用含时OFT(TDDFT)方法研究了它们的激发态。用长程修正泛函、CAM-B3LYP和OMEGA B97X-D计算的激发能与实验值符合得很好。利用基于密度泛函理论的波函数，采用广义Mulliken-Hush(GMH)方法计算电荷转移积分。此外，利用Marcus理论计算了光致电荷分离速率常数k(CS)和电荷复合速率常数k(CR)。计算结果表明，染料与TiO2团簇之间存在级联的电子转移通道，使得k(CS)值增大。相反，单一的电荷复合通道降低了k(CR)，与k(CS)相比可以忽略不计，表明电子复合不是有利的。
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 OFT (TDDFT) method. The excited energies, which were calculated using the long-range-corrected functionals, CAM-B3LYP and omega B97X-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 (k(CS)) and charge recombination rate constant (k(CR)) were calculated using Marcus theory. The calculated results showed that there were a cascade of electron transfer channels from the dye into the (TiO2) cluster, which increases the k(CS) value. In contrast, the single channel of charge recombination decreases the k(CR), value, which is negligible compared with k(CS), indicating that electron recombination is not favored.