Ethanol–water-assisted room temperature synthesis of CsPbBr₃/SiO₂ nanocomposites with high stability in ethanol

All-inorganic halide perovskites have attracted great attention by virtue of the merits of bright emission, tunable wavelength and narrow-band emission. Despite the excellent optical features, all-inorganic halide perovskite materials have suffered from intrinsic instability, which has limited their applications in various optoelectronic devices. To mitigate the intractable issue, we demonstrated the CsPbBr₃ nanoparticles decorated with smaller SiO₂ nanocrystals to passivate the surface defects; SiO₂ nanoparticles were applied as a barrier layer to maintain the optical property and enhance environmental stability. A facile in situ method was proposed to prepare CsPbBr₃/SiO₂ nanocomposites, in which an environmental ethanol/water solvent system was needed with the addition of tetraethyl orthosilicate (TEOS) as a silicon precursor. The obtained CsPbBr₃/SiO₂ nanocomposites have better optical characteristic and stability than bare CsPbBr₃ nanoparticles. Even 70% photoluminescence intensity of as-prepared CsPbBr₃/SiO₂ nanocomposites can be maintained after 168 h storage in ethanol. This newly developed synthesis will open up a new route for the fabrication of optoelectronic devices in an environmentally friendly way, and the as-obtained perovskite materials with improved stability will make them great potential for multifunctional optoelectronic devices.