In situ synthesis of blue-emitting bromide-based perovskite nanoplatelets towards unity quantum efficiency and ultrahigh stability

Abstract

All-inorganic cesium lead halide perovskite nanocrystals have been widely investigated as promising materials for lighting and display. The primary challenge for their practical application is the development of highly efficient and stable blue-emitting perovskites, which severely lag behind their red- and green-emitting counterparts. Here, we proposed a facile in situ cross-linking passivation strategy to address these issues. Using (3-aminopropyl)triethoxysilane as surface ligands and cross-linking agent, ultrapure blue emission (line width = 14 nm) and unity photoluminescence quantum yield were achieved from cross-linked passivated CsPbBr₃ nanoplatelets with an emission peak at ∼466 nm. The temperature dependence of time-averaged and time-resolved photoluminescence studies reveal the thermal facilitation process of radiative recombination and detrapping. Through an effective passivation strategy, the as-obtained perovskite nanoplatelets exhibit ultrahigh stability, including long-term storage, air-stability, polar-stability, and photostability. Moreover, the extraordinary photoluminescence quantum yield, ultrahigh stability, and ease of preparation make it potential for practical applications in optoelectronic devices.