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.