Mesoporous Trap of Molecular Sieves via Water-Selective Capture for Stable Perovskite Quantum Dots

Attaining good stability while maintaining superior properties is one of the main requirements for the application of organic/inorganic halide perovskite CH 3 NH 3 PbBr 3 quantum dots (QDs) in lighting and display devices. However, stability and surface defects of QDs have been negatively affected because of the presence of H 2 O in solvents and humidity in air. Herein, a facile strategy is proposed to synthesize colloidal QDs with long-term luminescent and high quantum yield (QY) (92.1%) at room temperature. Molecular sieves are used with a pore size of 3 Å to selectively induce adsorption and reflection according to the size of the diameter. H 2 O removal is facilitated by the addition of molecular sieves to a polar solvent, thereby generating dehydrated QDs. Contact angle measurement and surface energy calculation (Owen–Wendt method) of a thin film coated with the dehydrated QDs confirm hydrophobicity. Moreover, 30 days after coating thin films with pristine and dehydrated QDs, cracks are observed on the pristine QD-coated thin film surface due to the decomposition of QDs. This is a crack formed by the separation of the QD ligand and the perovskite decomposition. Furthermore, dehydrated QDs maintained a PL intensity of 83.7% after 30 days. The proposed synthesis method is effective for the rational design of high-quality QDs having high efficiency and long-term stability.