Blue-Emitting CsPbBr 3 Quantum Dots with Enhanced Performance through In Situ Aminosilane Passivation

Blue-emitting perovskite quantum dots hold significant promise for applications in lighting and display technologies, however, their luminous efficiency and stability still lag behind those of red- and green-emitting counterparts. Unlike previous passivation strategies using monoaminosilanes, this study employs siloxane molecules with bis-amino functional groups (BIS) to prepare CsPbBr3 quantum dots via in situ passivation at room temperature. By leveraging the synergistic coordination of the bis-amino groups and the hydrophobic properties of the Si–O backbone, highly efficient passivation of surface defects on the quantum dots is achieved. Following BIS passivation, the photoluminescence quantum yield (PLQY) of the quantum dots increased significantly from 17.16% to 87.36%, the emission peak shifted blueward by 14 to 491 nm, and the half-width at half-maximum narrowed to 18.82 nm, demonstrating excellent blue light emission performance and color purity. Additionally, the passivation treatment effectively enhanced the environmental stability of the quantum dots. This work presents a straightforward and efficient strategy for the controlled synthesis of highly luminescent blue-emitting perovskite quantum dots, demonstrating their potential application in optoelectronic devices.