Augmentation of Halide Vacancy Rectification through Copper Ion Polarization in Nonsubstituted Porphyrin for Printable Carbon-Based Perovskite Solar Cells

In the context of porphyrins, enhancing their charge transfer or defect repair function in perovskite solar cells has been a primary focus of the current research, particularly through the introduction of functional groups. This enhancement of the porphyrin framework’s defect repair capability is a crucial strategy for simplifying device assembly processes and reducing costs. In our study, we introduced metal ions into the porphyrin ring via a straightforward one-step reaction, which induced polarization of the large π bond electron cloud within the ring, thereby augmenting its interaction with perovskite defect states. Our research discovered that the introduction of copper ions could significantly increase the dipole moment of the porphyrin ring from 0.0062 to 0.0737D, which is the fundamental reason for ion-induced passivation enhancement. The introduction of copper ions also strengthens the binding ability of the negative electron end with halogen vacancies (uncoordinated Pb²⁺) and inhibits the migration of I^– ions. As a result, the photovoltaic conversion efficiency of fully printable mesoscopic perovskite solar cells (p-MPSCs) increased from 14.15% in the control group to 16.13%. This work has thus opened a new pathway for enhancing the ability to repair perovskite defect states through the electron induction of the porphyrin ring.