Stability study of all-inorganic perovskite CsPbBr3 QDs@SiO2/EVA film composites prepared by one-step

Abstract

CsPbX3 (X = Cl, Br, I) all-inorganic perovskite quantum dots have attracted extensive attention from researchers recently. However, the further development is confined by serious stability problems. In this work, the CsPbBr3 QDs@SiO2/EVA films were prepared by supersaturated recrystallization, and SEM, EDS, XRD, FT-IR and PL were used to study microstructure, phase composition, and optical properties. Results show that during the preparation process, the amounts of precursor added would affect the fluorescence emission intensity of materials. The preparation method of films is simple, easy to operate, low cost, and beneficial to commercial large-scale production. In a typical synthesis, PbBr2 and CsBr are dissolved in DMF, and then oleic acid (OA) and oleylamine (OAm) as ligands are added to stabilize the DMF−PbBr2−CsBr precursor solution. When the addition of TEOS is 0.06 mL, the PL peak strength of prepared films is higher and the thickness of CsPbBr3 QDs@SiO2/EVA films is about 100 μm and flexible enough to be bent. At room temperature, the retention of fluorescence intensity of films is 67.4% after 30 d in the air, the retention is 63.6% after 40 h in the water, and the retention is 72.1% after 40 h under the UV light. EVA resins and SiO2 coating can effectively isolate the contact between quantum dots and moisture and delay the intrusion of oxygen, which significantly improves the stability of pure quantum dots.