Instantaneous Aqueous Spray Synthesis of Halide-Encapsulated CsPb(Cl/Br) 3 Quantum Dots for Stable Green to Pure-Blue Mini/Micro-LEDs

Abstract

CsPbX 3 (X = I, Br, Cl) perovskite quantum dots (QDs) have shown great potential in optoelectronic devices due to their wide tunable bandgap, high photoluminescence quantum yield, and narrow emission spectra. Currently, methods for regulating blue light emission through component engineering or dimensional engineering suffer from issues such as halogen phase separation and increased defects, making it difficult to meet the strict requirements of display technology for pure blue light (CIE y < 0.15). Additionally, traditional synthesis processes are complex and have poor compatibility with Micro-LED miniaturization technology, which restricts their industrial application. Therefore, this study proposes an efficient and green spray drying method. By dissolving the perovskite precursors and halide salts in an aqueous solution, CsPb(Cl/Br) 3 QDs can be rapidly (<10 s) synthesized without organic solvents, and continuous tuning from green to blue light is achieved. This method effectively suppresses surface defects and phase separation through Cl element encapsulation, significantly enhancing stability.Moreover, its excellent processability supports spraying and film formation on any substrate, enabling the direct preparation of highly uniform Mini/Micro-LED pixel units. This technology provides a new approach for large-scale, low-cost manufacturing of perovskite QDs and is expected to accelerate the commercialization process of next-generation display technologies.