Water-Stable, Fluorescent Organic−Inorganic Hybrid and Fully Inorganic Perovskites

Stabilization of perovskites without addition of foreign surface-passivating ligands in aqueous media is essential for their applications in optoelectronics, biomedical science, and catalysis. However, these materials instantly degrade in water due to its intrinsic ionic nature. By controlling the peripheral layer of octahedral perovskite geometry, we reproducibly synthesized a series of rod-shaped fluorescent hybrid perovskites in both acidic and basic media at ambient conditions in large scale without capping ligands. The band gap is tunable from the red to sky-blue region with sharp emission. The lead bromide perovskites are stable more than 6 months in water without structural change. Our simple synthetic route has resolved the longstanding problems for its practical application in aqueous environment.