Hybrid natural–inorganic steel halide perovskites (HOIPs) have gained vital analysis curiosity attributable to their tunable optoelectronic properties and ease of fabrication. Enhancing the soundness and effectivity of perovskite supplies could be achieved by way of the passivation of faulty surfaces and the development of interfacial properties. On this examine, we introduce a zwitterionic compound, PPS (3-(1-pyridinio)-1-propanesulfonate), as a bifunctional materials that serves as an additive and an interlayer. Incorporating PPS into the perovskite movie successfully reduces each positively and negatively charged defects, resulting in improved floor morphology and a discount in undesired cost provider recombination. Moreover, the formation of a PPS interlayer on SnO2 improves the SnO2/perovskite interfacial traits, thereby enhancing cost provider extraction. Because of this, the photodetector displays a low darkish present of 6.05 × 10−11 A, a wonderful responsivity of 5.93 A W−1, a detectivity of 1.51 × 1013 J, and an on/off ratio of 1.2 × 104 underneath open-air circumstances. Furthermore, the gadget demonstrates excellent stability, retaining 80% of its authentic responsivity in an ambient surroundings. This work highlights the nice potential of dual-functional supplies for defect passivation in future optoelectronic units, emphasizing the significance of floor modification and interface engineering for improved efficiency and stability.