Computational Investigation of Acene-Modified Zinc-Porphyrin Based Sensitizers for Dye-Sensitized Solar Cells

A series of acene-modified zinc-porphyrin dyes (benzene to pentacene, denoted as LAC-1 to LAC-5) were chosen to examine their performance as photosensitizers in dye-sensitized solar cells (DSSCs). Their structural, electronic, and optical properties were investigated at the DFT/TDDFT levels using various theoretical models (i.e., the gas phase model and the implicit/explicit solvent model). The dye@TiO2 complex was used to investigate the dye/semiconductor interfaces using both the cluster and periodic models. After a careful examination of the dependence of the results on different theoretical approaches, some basic principles could be derived based on the theoretical investigation of structure–function relationships in isolated dyes and dye–TiO2 assemblies. Based on these ideas, some general suggestions can be proposed for the future design of dyes for use in DSSCs. For instance, the DFT functionals used in estimating the critical parameters for DSSCs should be carefully validated. Sometimes the perform...