This work presents a systematic investigation of porphyrin sensitizers for application in dye-sensitized solar cells (DSSCs). Density functional theory calculations, including both static and time-dependent methods, were employed to evaluate a series of candidate dyes for their potential to achieve high power conversion efficiency. The well-established SM315 dye, known for its record-breaking PCE of 13%, was adopted as a reference point. A range of metal atoms including alkaline-earth and 3d transition metals were screened, Ca was identified as the most promising metal for light capture and conversion. Ca–porphyrin-based sensitizer was further modified by introducing different axial ligands and four distinct bridging units. The designed dyes exhibit red-shifted absorption spectra and optimal frontier orbital alignment with the semiconductor's conduction band, promoting efficient light capture and charge transfer. In addition to these core parameters, a comprehensive analysis of light harvesting efficiency (LHE), reorganization energy (λ), short-circuit current density (J_SC), exciton binding energy (EBE), open-circuit voltage (V_OC), electron transfer rate (k), polarization (α) and hyperpolarization (β_tot) collectively paint a clear picture of superior light capture, efficient charge transport dynamics, and minimized energy losses within the designed dyes. This ultimately translates to the remarkable power conversion efficiency (PCE) exceeding 27% achieved by the specifically designed dye with the Ca as metal atom, 4,4′-bipyridine as axial ligands and cyclopenta-1,3-diene as bridging unit, surpassing the performance of SM315 dye (13% PCE). This systematic study combines the design of high-performance porphyrin sensitizers through molecular engineering with a comprehensive investigation of their impact on DSSC function using advanced computational methods.

中文翻译：

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通过金属、配体和桥修饰设计高效的卟啉敏化剂：DFT 研究


这项工作对卟啉敏化剂在染料敏化太阳能电池 （DSSC） 中的应用进行了系统研究。采用密度泛函理论计算，包括静态和时间依赖性方法，来评估一系列候选染料实现高功率转换效率的潜力。成熟的 SM315 染料以其破纪录的 13% 的 PCE 而闻名，被用作参考点。筛选了包括碱土和 3d 过渡金属在内的一系列金属原子，Ca 被确定为最有前途的光捕获和转换金属。通过引入不同的轴向配体和四个不同的桥接单元，对基于 Ca-卟啉的敏化剂进行了进一步修饰。设计的染料表现出红移吸收光谱和与半导体导带的最佳前沿轨道对准，促进高效的光捕获和电荷转移。除了这些核心参数外，还对光收集效率 （LHE）、重组能 （λ）、短路电流密度 （J_SC）、激子结合能 （EBE）、开路电压 （V_OC）、电子转移速率 （k）、极化 （α） 和超极化 （β_进行综合分析） 共同描绘了设计染料中卓越的光捕获、高效的电荷传输动力学和最小的能量损失。这最终转化为以 Ca 为金属原子、4,4′-联吡啶为轴向配体和环戊-1,3-二烯为桥接单元的专门设计染料实现了超过 27% 的显着功率转换效率 （PCE），超过了 SM315 染料 （13% PCE） 的性能。 这项系统研究通过分子工程设计高性能卟啉增敏剂，并使用先进的计算方法全面研究它们对 DSSC 功能的影响。