Highly Luminescent Cesium Lead Halide Perovskite Nanocrystals Stabilized in Glasses for Light‐Emitting Applications

Cesium lead halide (CsPbX 3 ) nanocrystals have great potential for photovoltaic and optoelectronic applications, but they are sensitive to oxygen, moisture, and light irradiation. Embedding these CsPbX 3 nanocrystals into all‐inorganic amorphous solid matrices such as glass is expected to improve their stability. In this work, CsPbX 3 nanocrystals are precipitated in boro‐germanate glasses with tunable composition, absorption, and photoluminescence. Quantum efficiency of CsPbBr 3 nanocrystals in glass can be as high as ≈80% and ≈20% for CsPb(Cl/Br) 3 and CsPb(Br/I) 3 nanocrystals, respectively. Thermo‐ and photostabilities of CsPbX 3 nanocrystals in glass are greatly improved due to the inert nature of glasses, and intense laser irradiation‐induced damage to CsPbX 3 nanocrystals is recoverable through thermal annealing. With CsPbBr 3 nanocrystal‐embedded glass slices, a green light‐emitting device with a luminous efficiency of ≈120 lm W −1 and an external quantum yield of ≈30% is achieved. A white‐light‐emitting device consisting of CsPbBr 3 nanocrystals and CsPb(Br/I) 3 nanocrystal–embedded glass slices shows luminous efficiency in the range of 50–60 lm W −1 and external quantum yield of 20–25%. The thermo‐ and photostabilities along with the chemical stability of CsPbX 3 nanocrystal–embedded glasses are promising materials for photoluminescence related applications.