Introduction of methoxy and trifluoromethyl groups into zinc porphyrin sensitizers applications in self-assembled dye-sensitized solar cells

Abstract

In this study, we have successfully constructed two novel self-assembled composites, the ZnPx-ZnPAc (x = 1,2), which based on zinc porphyrin derivatives, and applied them to the development of dye-sensitized solar cells. The upper dye of these self-assembly’s features zinc porphyrin (ZnPx) as the core unit, while two different electron donors, methoxy (P1) and trifluoromethyl (P2), are introduced to enhance their photovoltaic properties. Photoelectrochemical studies showed that the power conversion efficiency of ZnP1-ZnPAc was superior to that of ZnP2-ZnPAc because ZnP1-ZnPAc had larger J_sc and V_oc, which could be attributed to the stronger electron-donating ability of methoxy than trifluoromethyl. To further validate the photoelectrochemical results, we also characterized the assembly mode by spectroscopy, theoretical calculations and electrochemical impedance spectroscopy. And the measurements were consistent with the conclusions.