Engineering Green- to Blue-Emitting CsPbBr₃ Quantum Dots in Nanozeolite with High Stability for Backlight Display Application.

Abstract

The performance of blue devices utilizing perovskite quantum dots (PQDs) has lagged remarkably behind that of green light-emitting diodes because of low luminescence quantum yields and poor spectral stability. Here, benefiting from the rapid and short diffusion paths within the nanosized silicalite-1 (N-Si-1) zeolite (∼40 nm) channels, CsPbBr₃ PQDs encapsulated within N-Si-1 show a high dispersion with an ultrasmall particle size of ∼2.38 nm and a blue emission of 474 nm with a high photoluminescence quantum yield (PLQY) of 44.4%. Subsequently, the surface hydrophobization of CsPbBr₃-N-Si-1 using octadecyltrimethoxysilane (ODTMS) enables ultrastable blue luminescence. A white-light-emitting diode (WLED) device with CIE color coordinates (0.31, 0.28) was constructed by combining CsPbBr₃-M (blue), CsPbBr₃-N-Si-1 (green), and KSF:Mn⁴⁺ phosphor (red) on a 365 nm chip. This work introduces a feasible strategy to modulate the emission of CsPbBr₃ PQDs through a strong confinement effect within a hydrophobic nanozeolite matrix, offering promising applications in backlight displays.