Ultrastable Perovskite through a SiO₂ and PbSO₄ Double Protection Strategy

Perovskites have gained significant attention due to their excellent optoelectronic properties. However, the poor stability of perovskites hinders their practical applications. To address this issue, we propose a facile approach to synthesize stable CsPbBr3 nanomaterials by embedding them into a SiO2 matrix followed by an in situ PbSO4 shell coating on their surfaces. After the encapsulation, the CsPbBr3@PbSO4/SiO2 powder exhibits high photoluminescence quantum yield (PLQY, ∼85%) due to reduced defects. Most importantly, the CsPbBr3@PbSO4/SiO2 powder shows robust stability under many harsh conditions, such as maintaining its PL in water (for 1 year), concentrated hydrochloric acid (HCl) aqueous solution and hydrobromic acid (HBr) aqueous solution (for 25 days), boiling water (for 24 h), high temperature (500 °C for 24 h), and light irradiation (365 nm for 3 months). This work not only provides a strategy for the facile preparation of ultrastable and efficient perovskites but also shows great potential for practical applications such as solid lighting and backlight displays.