Dual-Encapsulation for Highly Stable All-Inorganic Perovskite Quantum Dots for Long-Term Storage and Reuse in White Light-Emitting Diodes

Abstract Although perovskite quantum dots (PQDs) have fascinating optical performances and wide uses in light-emitting diodes (LEDs), laser and photodetectors etc., their commercialization and practical applications are seriously hampered by the poor stability against moisture or water, heat, photo-oxidation and ion exchange. Herein, we report a dually encapsulating strategy of PQDs in fluorinated silica (FSiO2) and porous polydimethylsiloxane (PPDMS) foam. Owning to the superhydrophobic and thermal insulation layers, the dually-encapsulated CsPbBr3 QDs are very stable in the moisture, heat, and irradiation environment and can be long-term stored in air environment for at least 3 months without losing their optical properties. Moreover, the FSiO2-coated CsPbBr3 QDs can be easily released out from PPDMS foam and applied in white LEDs to display pure white emission with ideal CIE (Commission Internationale de L’Eclairage 1931) chromaticity coordinate of (0.33, 0.33). This novel dual-encapsulation strategy through combination of solid airtight shells and thermally insulated porous materials provides a new idea and solution to improve the stability of perovskite quantum dots.