Improved luminescent performances of CsPbI3 perovskite quantum dots via optimizing the proportion of boron-silicate glass and precipitation processing

In-situ crystallization of CsPbX3 perovskite quantum dots (PQDs) in inorganic glasses has been considered to be a feasible protective method to enhance its stability when exposing in air. However, comparing to CsPbCl3 PQDs and CsPbBr3 PQDs inside glass, CsPbI3 PQDs@glass still suffers from the low photoluminescence quantum yield (PLQY) and extremely poor stability, resulting in keeping away from practical application. Herein, the rigidity of borosilicate glass is optimized through adjusting the molar ratio of B2O3/SiO2 in the glass system, which allows fine-control of precipitation and growth of quantum dots. The highest PLQY value of glass stabilized CsPbI3 reaches 17.1%. Importantly, because of the dense and strong protection of the glass, CsPbI3 PQDs@glass exhibits excellent water resistance and still maintain about 95% luminescence after soaking them in water for 60 days. A series of prototypes light-emitting diode devices were combined by coupling LuAG phosphor, as-made red CsPbI3 PQDs@glass powders with a commercial blue-chip, yielding bright white light luminescence with optimal luminous efficiency of 95 lm/W, color temperature of 5755 K and high color rendering index of 95.

Automated summary

In-situ crystallization of CsPbX3 perovskite quantum dots in inorganic glasses enhances their stability when exposed to air. By optimizing the rigidity of borosilicate glass, the precipitation and growth of quantum dots can be finely controlled. The glass-stabilized CsPbI3 PQDs exhibit excellent water resistance and maintain high luminescence after prolonged water exposure. The combination of CsPbI3 PQDs@glass with other materials yields bright white light with high efficiency and color rendering index.