Stable, Low-Threshold Amplification Spontaneous Emission of Blue-Emitting CsPbCl₂Br₁ Perovskite Nanocrystals Glasses with Controlled Crystallization

The inherent instability severely limits the applications of cesium lead halide (CsPbX 3 ) perovskite quantum dots (PQDs). Herein, introducing these CsPbX 3 PQDs into all-inorganic amorphous solid matrices is a simple and effective encapsulation strategy to achieve prominent chemical stability. In this work, CsPbCl 2 Br 1 PQDs are precipitated in borosilicate glasses with the aid of a crystallization control process, followed by the explorations of the optical properties and amplified spontaneous emission (ASE) performance. Our results indicate that the prepared CsPbCl 2 Br 1 PQDs-embedded glasses exhibit tunable photoluminescence (PL) emissions and absorption edges by controlling the heat-treatment temperatures. Simultaneously, ASE behaviors of CsPbCl 2 Br 1 PQDs-embedded inorganic glasses have been first demonstrated under 800 nm fs laser excitation at room temperature, the threshold reduces from 1.24 to 0.19 mJ/cm 2 as the crystallization temperatures increase from 440 to 530 °C. Finally, a robust inorganic glass host can insulate the air from CsPbX 3 PQDs, which enables the attainment of CsPbCl 2 Br 1 PQDs stability, including better thermostability and photostability. It can be seen that the heat-treatment temperature in the fabrication process is of critical importance in affecting the CsPbX 3 PQDs crystallization and quality, which provides a new strategy for laser applications.