Enhanced stability and confinement effects of Cs4PbBr6 quantum dots via mechanochemical immobilization on MOF nodes

Abstract

Mechanochemical has emerged as an eco-friendly, efficient, and upscalable tool for the synthesis of perovskite quantum dots (PQDs). However, achieving control over the size and ensuring good mono-dispersion of PQDs by mechanochemistry, while simultaneously increasing their stability remains a great challenge. Herein, we specifically chose a lead bromine-based MOF (PbBr-MOF) with [Pb2Br3]+ nodes and utilized the uniform distribution of [Pb2Br3]+ to induce the in-situ confined growth of Cs4PbBr6 QDs via bottom-up mechanochemical approach for the first time, denoted as Cs4PbBr6@PbBr-MOF. The Cs4PbBr6 QDs uniform and firmly anchor in PbBr-MOF through [Pb2Br3]+ nodes, preventing their aggregation and enhancing quantum confinement effects. Highly dispersed Cs4PbBr6 QDs (3.86 ± 0.61 nm) exhibit high photoluminescence quantum yield (31%) and notable durability in various solvents. Furthermore, Cs4PbBr6@PbBr-MOF demonstrates excellent performance as a temperature sensor, with maximum absolute (Sa) and relative (Sr) temperature sensitivities of up to 0.013 K−1 and 3.41% K−1, respectively.