High-performance all-inorganic CsPbBr₃ quantum dots with a low-threshold amplified spontaneous emission

All-inorganic halide perovskite CsPbX₃(X = Br/Cl/I)quantum dots have gained a considerable attention in the optoelectronic fields. However, the high cost and poor stability of the prepared CsPbX₃ quantum dots (QDs) are inevitable challenges for their future practical applications. And the high-performance CsPbX₃ QDs are always needed. Herein, a facile and low-cost synthesis scheme was adopted to prepare the CsPbBr₃ QDs modified by lead bromide (PbBr₂) and tetraoctylammonium bromide (TOAB) ligands at room temperature in open air. The prepared CsPbBr₃ QDs exhibited a high photoluminescence quantum yield (PLQY) of 96.6% and a low amplified spontaneous emission (ASE) threshold of 12.6 µJ/cm². Stable ASE intensity with little degradation was also realized from the CsPbBr₃ QDs doped with PMMA. Furthermore, the enhanced ASE properties of the CsPbBr₃ QDs-doped PMMA based on distributed feedback (DFB) substrate was achieved with a lower threshold of 3.6 µJ/cm², which is 28.6% of that of the (PbBr₂+ TOAB)-treated CsPbBr₃ QDs without PMMA. This work exhibits a promising potential in the on-chip light source.