Low-Temperature Synthesis of Highly Stable Blue-Emitting Perovskite CsPbBr₃ Quantum Dots

Blue-emitting CsPbBr₃ perovskite quantum dots (PQDs) possess tremendous potential applications in full-color display and lighting field. However, the low-energy-consumption synthesis of blue-emitting CsPbBr₃ PQDs at low temperatures remains a challenge. In this study, we present a novel, simple, and cost-effective method for synthesizing high-quality blue-emitting CsPbBr₃ PQDs under ambient conditions based on an antisolvent technique. In this method, the rate of crystal growth is mitigated effectively at low temperatures, circumventing the formation of large quantum dots and the agglomeration of quantum dots in the solution with the proper ratio of ligands. The synthesized CsPbBr₃ PQDs exhibit a blue photoluminescence emission at a wavelength of ∼457 nm with a narrow full width at half-maximum of ∼22 nm. Over a period of 44 days, the photoluminescence quantum yield (PLQY) of the as-prepared CsPbBr₃ PQDs reaches 87% with temperature regulation, which is a distinct improvement compared with an initial PLQY of 67%. The stability test of blue-emitting PMMA-CsPbBr₃ PQD thin films illustrates that the polymer-PQD films in the air, water, and alkaline solution are more stable than in HCl acid. The approach presented in this study is expected to open up new avenues for producing high-quality blue-emitting PQDs at low cost, contributing to overcoming the present loopholes existing in this slow-paced field of blue-emitting PQDs and further enhancing their potential applications in optoelectronic devices.