Encapsulation of Dual‐Passivated Perovskite Quantum Dots for Bio‐Imaging

Due to their marvelous electrical and optical properties, perovskite nanocrystals have reached remarkable landmarks in solar cells, light‐emitting diodes, and photodetectors. However, the intrinsic instability of ionic perovskites, which would undergo an undesirable phase transition and decompose rapidly in ambient humidity, limits their long‐term practical deployment. To address this challenge, halogenated trimethoxysilane as the passivation additive is chosen, which utilizes simultaneous halide and silica passivation to enhance the stability of perovskite nanoparticles via a dual‐passivation mechanism. The processable nanoparticles show high photoluminescence quantum yield, tunable fluorescence wavelength, and excellent resistance against air and water, highlighting great potential as green to deep‐red bio‐labels after further phospholipid encapsulation. This work demonstrates that the dual‐passivation mechanism could be used to maintain the long‐term stability of ionic crystals, which sheds light on the opportunity of halide perovskite nanoparticles for usage in a humid environment. The halogenated trimethoxysilane is chosen as the dual‐passivated additive, which enhances the stability of perovskite quantum dots (QDs) through simultaneous halide and silica passivation. After further phospholipid encapsulation, the water‐stable perovskite QDs are successfully utilized as the green to deep‐red bio‐labels, enlightening the great potentials of halide perovskite QDs for widespread application.