Synthesis of zinc porphyrin sensitizers containing heteroatoms and polybenzene ring donor groups for dye-sensitized solar cells

Porphyrin sensitizers were extensively studied due to their exceptional performance in dye-sensitized solar cells (DSSCs). In this study, three sensitizers (ZnP1, ZnP2, and ZnP3) with D-π-A structures containing heteroatom functional groups, such as triphenylamine, thianthrene and dibenzothiophene as electron donors, were designed and synthesized. The benzoic acid group, which functioned as an electron acceptor, and the strategically incorporated acetylene group enhance the light-harvesting abilities of the three sensitizers. Compared to ZnP2′s thianthrene and ZnP3′s dibenzothiophene, the incorporation of the triphenylamine electron donor in ZnP1 significantly improved electron transfer efficiency, short-circuit current density, and conversion efficiency. It also increased electron recombination resistance and prolonged electron lifetime, resulting in the best performance. Density functional theory (DFT) calculations confirmed these experimental findings.