Study of the microscopic mechanism of stepwise charge injection in co-sensitive DSSCs in the framework of a D–π–A dye and chlorophyll

The results suggest that for CXC22, adding an anthracene and acetylene group in the conjugate bridge greatly enhances the molecule's absorption wavelength and molar extinction coefficient; CXC22 also has significant advantages in the intramolecular charge transfer and comparatively better dye regeneration and electron injection. These parameters cause CXC22 to have a higher PCE. Subsequently, CXC22 and the chlorophyll molecule (CHL7) were selected for co-sensitization to regulate performance. The stable structure in the co-sensitization configuration was screened, and the absorption spectrum characteristics and charge transfer mechanisms were revealed for the co-sensitization system. The designed evaluation model predicted that the PCE of CO1 (the cosensitive system of CXC22 and TY6 in H-H configuration is referred to as CO1) could reach 16.78%. This work provides an idea for developing an efficient dye-sensitized solar cell system.