Fig. 1. Reaction process schematics of the formation of CsPbBr3@SiO2 QDs.

Fig. 2. (a) XRD patterns, (b) FTIR spectra, (c) XPS full scan of CsPbBr3@SiO2 QDs and the high-resolution XPS profiles of (d) Cs 3d, (e) Pb 4f, (f) Br 3d, (g) Si 2p, and (h) O 1s.

Fig. 3. (a), (c) TEM images and (b), (d) HRTEM images of pure CsPbBr3 and CsPbBr3@SiO2 QDs. (e) Element distribution of CsPbBr3@SiO2 QDs.

Fig. 4. (a) Photographs of CsPbBr3 and CsPbBr3@SiO2 QDs solution with/without UV light and films with UV light. (b) PL intensity, (c) Absorption and PL spectra, and (d) PL decay curves of CsPbBr3 and CsPbBr3@SiO2 QDs.

Fig. 5. PL spectra of (a) CsPbBr3 and (b) CsPbBr3@SiO2. (c) Normalized PL intensity of CsPbBr3 and CsPbBr3@SiO2 under continuous heating at 60°C.

Fig. 6. (a) Pump-intensity dependence of the emission from the CsPbBr3 film under an 800 nm femtosecond laser excitation. (b) Output intensity (red) and linewidth (black) as functions of pump energy density for CsPbBr3 film under a femtosecond laser excitation of 800 nm. (c) Pump-intensity dependence of the emission from the CsPbBr3@SiO2 film under an 800 nm femtosecond laser excitation. (d) Output intensity (red) and linewidth (black) as functions of pump energy density for CsPbBr3@SiO2 film under a femtosecond laser excitation of 800 nm.