Ultrastable Zero-Dimensional Cs₄PbBr₆ Perovskite Quantum Dot Glass

Abstract

The\ninstability of all-inorganic perovskites and poor understanding\nof the photoluminescence mechanisms have hindered their practical\napplications. While a large body of work on 3-D perovskite phases\nis available in the literature, the promising zero-dimensional (0-D)\nphase perovskite materials are still poorly understood. Herein, we\nreport a new synthesis method for the production of 0-D Cs₄PbBr₆ perovskite quantum dots (QDs) in glass using a combination\nof Cs₂CO₃ concentration and heat-treatment temperature\noptimization. The differences in structure, morphology, and photoluminescence\n(PL) between the 0-D Cs₄PbBr₆ QDs and the 3-D\nCsPbBr₃ QDs in glass were studied in detail. Cs₄PbBr₆ QD glass with high transmittance displayed a blue-shift\nPL emission centered at 503 nm, a narrow full width at half-maximum\n(fwhm, ∼20 nm), a high photoluminescence quantum yield (PLQY,\n∼22%), and excellent long-term stability, thereby, advancing\nthe study of these materials. It was demonstrated that Cs₄PbBr₆ displayed unique luminescent properties in correlation\nwith the intrinsic defect states in the mid-band gap.