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.

Stable, Low-Threshold Amplification Spontaneous Emission of Blue-Emitting CsPbCl2Br1 Perovskite Nanocrystals Glasses with Controlled Crystallization

“…For an alternative, an inorganic glass host is identified as a robust medium to provide effective protection for PQDs. As a matter of fact, there have been many successful cases of encapsulating PQDs into a glass matrix, , but the glass matrix is only a carrier and a protective medium, which possesses the robust and stable characteristics to better protect the CsPbCl 2 Br 1 PQDs, maintain their structural integrity, and make them more resistant to high-power laser irradiation. , However, the basis to achieving a low-threshold ASE is the crystallization of the CsPbCl 2 Br 1 PQDs themselves in the glass. The heat-treatment temperature is a key factor affecting the crystallinity, quality, and particle size of the PQDs in a glass matrix.…”

Improvement in optical properties of Cs4PbBr6 nanocrystals using aprotic polar purification solvent

“…However, the solvent effect is improved due to polarity, and finally decreases the size of Cs 4 PbBr 6 nanocrystals. Additionally, the size of sample B and sample C are smaller than those previously reported in the literature 21 and can produce a quantum size effect, which can strongly influence the tuneable PL properties. 22 …”

Structural effects on the luminescence properties of CsPbI3 nanocrystals

“…In NCs phonon propagation can be disrupted by scattering from the nanocrystal surface, causing phonon confinement within the nanograin 38 and enhancing the coupling of exciton with lattice phonons in smaller particles. 39 In addition, bonding with ligands has also been shown to enhance EP coupling: 40 again, a larger contribution of the bulk can explain the lack of the observed enhancement for less strongly confined NCs.…”