Ultrastable Zero-Dimensional Cs₄PbBr₆ Perovskite Quantum Dot Glass

Abstract

The instability of all-inorganic perovskites and poor understanding of the photoluminescence mechanisms have hindered their practical applications. While a large body of work on 3-D perovskite phases is available in the literature, the promising zero-dimensional (0-D) phase perovskite materials are still poorly understood. Herein, we report a new synthesis method for the production of 0-D Cs4PbBr6 perovskite quantum dots (QDs) in glass using a combination of Cs2CO3 concentration and heat-treatment temperature optimization. The differences in structure, morphology, and photoluminescence (PL) between the 0-D Cs4PbBr6 QDs and the 3-D CsPbBr3 QDs in glass were studied in detail. Cs4PbBr6 QD glass with high transmittance displayed a blue-shift PL emission centered at 503 nm, a narrow full width at half-maximum (fwhm, ∼20 nm), a high photoluminescence quantum yield (PLQY, ∼22%), and excellent long-term stability, thereby, advancing the study of these materials. It was demonstrated that Cs4PbBr6 displayed unique luminescent properties in correlation with the intrinsic defect states in the mid-band gap.