Engineering of the interface between the perovskite and hole transport layer (HTL) has been crucial to achieving high performance. In this study, two interfacial materials, MN-CZ and CN-CZ, are designed by systematically regulating the group substitution site to study the relationship between spatial conformation and the passivation effect. The passivation groups of CN-CZ molecules exhibit a stronger "vector addition" effect, resulting in larger molecular dipoles and enhanced defect passivation and energy level regulation effects. Consequently, the CN-CZ-based perovskite solar cell (PSC) shows a high efficiency of 23.8%, which is much higher than that of the reference device. Meanwhile, the humidity and thermal stability of the unencapsulated device have been significantly improved.