Highly-efficient sensitizer with zinc porphyrin as building block: Insights from DFT calculations

摘要

To further improve the photoelectronic conversion efficiency of dye-sensitized solar cell, a series of novel D-pi-A dyes with Zn porphyrin as building block are evaluated with theoretical calculations. The effect of relative position of Zn-porphyrin (ZP) on the overall performance of D-pi-A dye has been investigated by means of density functional theory (DFT) and time-dependent DFT (TD-DFT) approaches. Through the analyzing the molecular geometry, electronic structure, transport properties and light harvesting and utilization of monomer dyes, dye-III is confirmed to be the most suitable one for DSSC application, due to its smaller HOMO-LUMO energy gap, broader absorption coverage, better transport capability, and larger short-circuit current density. Quantum dynamics simulation illustrates novel dyes constructed in current contribution are faster in electron transfer at dye@TiO2 interface. The overall efficiency of DSSC could be boosted if ZP unit was incorporated close to the acceptor group in D-pi-A dye. Our work is expected to provide theoretical guideline for further designing and screening prospective sensitizers for DSSC.