State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou, Gansu, 730050, China; Department of Applied Physics, Lanzhou University of Technology, Lanzhou, Gansu, 730050, China; College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou, Gansu, 730070, China.
Department of Applied Physics, Lanzhou University of Technology, Lanzhou, Gansu, 730050, China.
J Mol Graph Model. 2019 May;88:23-31. doi: 10.1016/j.jmgm.2018.12.014. Epub 2019 Jan 2.
Development of novel dye sensitizers with suitable optoelectronic properties is effective to improve the power conversion efficiency of dye-sensitized solar cells (DSSCs). Considering the effectiveness of conjugate bridges in modification of optoelectronic properties, based on the dye sensitizers C201, C203, C204 and C205, five kinds of organic dye sensitizers are designed with different thiophene-based moieties and the functionalized graphene flakes (GFs) as conjugate bridges. The performances of these dye sensitizers are analyzed in terms of the calculated geometries, electronic structures and excitation properties. The transition configurations and molecular orbitals of dye sensitizers suggest that bis-dimethylfluoreneaniline is effective electron donor, and the transitions of optical absorption in visible region are charge transfer excitations. The conjugate lengths, energy level alignments, light harvesting capabilities, excitation character, and transition properties, as well as the free energy variations for electron injection and dye regeneration support that the designed dye sensitizers are effective to be applied in DSSCs. Particularly, introducing the functionalized GF into conjugate bridges significantly elongate conjugate length, reduce orbital energy gap, lead to denser distribution of orbital energy, generate red-shift of absorption spectra, enhance light harvesting capability, increase absorption bands and coefficients. Therefore, introducing the functionalized GF into conjugate bridges is effective, and the designed panchromatic dye sensitizer C20x-GF-BTD must be better than other designed dye sensitizers for DSSCs.
开发具有合适光电性能的新型染料敏化剂对于提高染料敏化太阳能电池（DSSC）的功率转换效率非常有效。考虑到共轭桥在修饰光电性能方面的有效性，基于染料敏化剂 C201、C203、C204 和 C205，设计了五种不同噻吩基部分和功能化石墨烯片（GFs）作为共轭桥的有机染料敏化剂。从计算几何形状、电子结构和激发特性方面分析了这些染料敏化剂的性能。染料敏化剂的跃迁构型和分子轨道表明，双二甲氟苯胺是有效的电子给体，而可见光区的光吸收跃迁是电荷转移激发。共轭长度、能级排列、光捕获能力、激发特性、跃迁特性以及电子注入和染料再生的自由能变化表明，所设计的染料敏化剂可有效应用于 DSSC。特别是，将功能化 GF 引入共轭桥中显著延长了共轭长度，降低了轨道能隙，导致轨道能更密集地分布，吸收光谱发生红移，增强了光捕获能力，增加了吸收带和系数。因此，将功能化 GF 引入共轭桥中是有效的，设计的 panchromatic 染料敏化剂 C20x-GF-BTD 对于 DSSC 必须优于其他设计的染料敏化剂。
