Dual Layer-encapsulated Halide Perovskite with Enhanced Stability for Bioimaging

Organic-inorganic lead halide perovskite (OIHP) nanocrystals are an emerging class of high performing materials with application as the molecular probe for bioimaging. OIHP exhibits many desirable traits of fluorophores such as high quantum yield, excellent photoluminescence, large stokes-shift, high photostability, and infrared emission wavelengths. Despite its excellent properties, OIHP experiences poor stability when exposed to moisture, heat, or high energy wavelengths. Utilizing a dual layer-encapsulation comprising of silicon dioxide (SiO₂) and nonionic amphiphilic triblock copolymer (Pluronic F-127), stable OIHP can be obtained. This allows transfer of OIHP nanocrystals synthesized in organic solvent to an aqueous media while retaining their optical properties. As a result, the modified OIHPs exhibits improved stability, higher photoluminescence, and increased quantum yield (23%) compared to untreated OIHPs.