Microfluidic synthesis of monodispersed sharp emitting perovskite CsPbBr3 quantum dots via multidimensional parameterization

Abstract

Lead halide perovskite nanocrystals are highly valued in optoelectronics for their high photoluminescence quantum yield (PLQY) and tunable bandgap. However, producing blue-emitting CsPbBr₃ quantum dots (QDs) with high PLQY, a narrow emission bandgap (<30 nm), and a size-tunable energy bandgap is still challenging. Herein, we developed a microfluidic chip strategy to achieve a controllable, continuous, and stable synthesis of CsPbBr₃ QDs, optimizing multidimensional parameters such as the precursor solution concentration, reaction time, temperature, and the Cs/Pb mole precursor ratio to enhance the properties of the synthesized material. The blue-emitting CsPbBr₃ QDs with a sharp emission wavelength of 472 nm can be synthesized and their PLQY value reaches up to 41.9%, which is the highest value achieved using the microfluidic chip method for synthesizing blue-emitting CsPbBr₃ QDs. Notably, this strategy enables the synthesis of CsPbBr₃ QDs with an emission spectrum ranging from blue to green (463 nm to 522 nm). This work elucidates the synthetic kinetics of perovskite QDs via the microfluidic reaction and highlights microfluidics as a promising technique for scalable and high-quality nanocrystal fabrication.