Strong Confinement via 2D-to-3D Zeolite Transformation Enables Blue-Emitting CsPbBr3 Quantum Dots for Backlight Displays

Abstract

Blue-emitting CsPbBr₃ perovskite quantum dots (PQDs) typically face challenges such as low photoluminescence quantum yield (PLQY) and poor spectral stability, hindering their optoelectronic applications. Here, a feasible strategy was developed to encapsulate CsPbBr₃ PQDs within the supercages of three-dimensional (3D) MCM-22 zeolite via structural transformation from its two-dimensional (2D) layered precursor (MCM-22P). The CsBr and PbBr₂ were thoroughly mixed with high-surfacearea MCM-22P nanosheets. Upon high-temperature treatment, MCM-22P condenses into a 3D framework with nanoscale interlayer spaces effectively suppress CsPbBr₃ PQDs aggregation, enabling uniform confinement of ultrafine CsPbBr₃ PQDs (2.13 nm) with stable blue emission at 467 nm and a maximum PLQY of 45.31%. A white-light-emitting diode (WLED) device with CIE color coordinates (0.31, 0.30) was constructed by combining CsPbBr₃@MCM-22-6h (blue), CsPbBr₃@MCM-22-0.5h (green), and KSF:Mn⁴⁺ phosphors (red) on a 365 nm chip. This work offers a very simple strategy for developing bright and deep blue-emitting CsPbBr₃ PQDs for advanced optoelectronic applications.