High temperature solid reaction synthesis of ultra-stable CsPbI3–Cs4PbI6 nano-composites sealed in SiO2 particles

Rigid protection layers for the lead-halide perovskite effectively enhance its stability. In this work, for the most vulnerable CsPbI3 perovskite nanocrystals (PNCs), we introduced zero-dimensional perovskites Cs4PbI6 for protection in addition to already robust SiO2 all-inorganic encapsulation, via high-temperature solid-state synthesis. It is proven that the CsPbI3–Cs4PbI6 nano-composite not only maintains the emission peak location of CsPbI3 PeNCs at 700 nm with remarkable oxygen and water resistances, but also exhibits enhanced instant and long-term thermal stability compared with samples containing less amount of Cs4PbI6. The passivation of defects on the interface of CsPbI3–Cs4PbI6 contributes to the enhancement of photoluminescence quantum yield by 8%. These ultra stable CsPbI3–Cs4PbI6 nano-composites show potentials in the application of luminous and display industries.