Stability of core–shell structure CsPbX3@SiO2 (X = Cl,Br) perovskite quantum dots

[Display omitted] •The good stability of SiO2 is conducive to the long-term protection of the CsPbX3 quantum dots.•By controlling the hydrolysis rate and reaction time of TMOS and TEOS, CsPbX3@SiO2 quantum dots were obtained.•This work provides a new idea to encapsulate CsPbX3 with metal oxide at the single core–shell particle level. In this paper, CsPbX3@SiO2 (X = Cl, Br) with cubic morphology and stable optical properties have been developed. The average thickness of the SiO2 shell is 2 ∼ 6 nm, which has the effect of protecting CsPbX3 and isolating the external environment, passivating the surface and reducing the defect density, thus greatly improving the stability of CsPbX3 PQDs. Based on this, the advantages of APTES as a preparation system CsPbX3@SiO2 is revealed, the mechanism diagram is drawn and the stability improvement mechanism CsPbX3@SiO2 is analyzed in detail, which provides a new idea for the stability improvement of CsPbX3 perovskite quantum dots.