King Abdulaziz University, Chemistry Department, Faculty of Science, P.O Box 42805 Jeddah, 21589, Saudi Arabia; University of Jeddah, Chemistry Department, Faculty of Science, Jeddah, Saudi Arabia.
King Abdulaziz University, Chemistry Department, Faculty of Science, P.O Box 42805 Jeddah, 21589, Saudi Arabia.
J Mol Graph Model. 2021 May;104:107833. doi: 10.1016/j.jmgm.2021.107833. Epub 2021 Jan 5.
Dye aggregation causes poor performance of dye-sensitized solar cell (DSSC) applications through faster charge recombination of the photosensitizer with electrolyte. Triphenylamine (TBA)-based dyes feature a higher molar absorption coefficient and broadened wavelength but cannot absorb sunlight in the near-infrared (NIR) region. In contrast, the squaraine (SQ) photosensitizer, which is also called an NIR photosensitizer, has a maximum wavelength in the NIR region with high intensity. However, SQ dye suffers from dye aggregation due to its planar structure. The use of a co-sensitizer is one well-tested way to increase the power conversion efficiency (η) of solar cells by reducing dye aggregation and charge recombination. Using density functional theory (DFT) and time-dependent DFT (TDDFT), this work explains from a theoretical perspective the higher η values of the TZC1 and TZC2 dyes compared to that of asymmetric the SQ sensitizer (YR6) as free dyes. The electronic properties, reorganization energies, absorption and emission spectra, ICT parameters, and photovoltage parameters of the TZC1, TZC2, and YR6 dyes were computed using the M06/6-31G(d,p) level of theory in the gas phase and CHCl solvent (CPCM method). Additionally, the mono- and co-adsorption processes of TZC-based sensitizers with YR6 on the anatase (001) surface were investigated using periodic DFT calculations with the PBE + U/PAW method and the dispersion correction of the Grimme method D3. The results reveal that the use of the co-sensitized led to significant stabilization of the formed complexes by at least 1.21 eV, the panchromatic effect on the absorption spectra, and an increase in the light-harvesting ability in the NIR region, which improves the performance of DSSCs.
染料聚集会导致染料敏化太阳能电池（DSSC）性能下降，因为它会加速敏化剂与电解质之间的电荷复合。基于三苯胺（TBA）的染料具有更高的摩尔消光系数和更宽的波长，但不能吸收近红外（NIR）区域的太阳光。相比之下，方酸菁（SQ）敏化剂也称为 NIR 敏化剂，具有高强度的近红外区域最大波长。然而，SQ 染料由于其平面结构而容易发生聚集。使用共敏化剂是一种经过充分验证的方法，可以通过减少染料聚集和电荷复合来提高太阳能电池的功率转换效率（η）。本工作使用密度泛函理论（DFT）和含时密度泛函理论（TDDFT），从理论上解释了 TZC1 和 TZC2 染料的η值高于不对称 SQ 敏化剂（YR6）的原因，这两种敏化剂都是自由染料。使用 M06/6-31G(d,p)水平理论在气相和 CHCl 溶剂（CPCM 方法）中计算了 TZC1、TZC2 和 YR6 染料的电子性质、重排能、吸收和发射光谱、ICT 参数和光电压参数。此外，使用周期性 DFT 计算和 PBE + U/PAW 方法以及 Grimme 方法 D3 的色散校正，研究了 TZC 基敏化剂与 YR6 在锐钛矿（001）表面上的单吸附和共吸附过程。结果表明，共敏化剂的使用至少稳定了形成的配合物 1.21 eV，使吸收光谱产生全色效应，并增加了近红外区域的光捕获能力，从而提高了 DSSC 的性能。
