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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. [ABSTRACT FROM AUTHOR]

Rare-earth-doped luminescent thin films have been responsible for unprecedented positive impacts in optoelectronic devices with high lateral resolution, excellent thermal stability, and strong adhesion to the solid surface. However, limited emission intensity and high-cost fabrication routine deeply inhibit their practical and commercial applications. Here, we propose a grain orientation engineering strategy via simple and low-cost polymer-assisted deposition (PAD) to fabricate textured BaMoO 4 : Eu3+ thin films with highly improved emission intensity by reducing the lattice mismatch between the thin films and substrates. The high-quality <004>-textured BaMoO 4 : Eu3+ thin film mounted on the (001)-oriented Si substrate with the Lotgering factor F 004 of 94.6%, boosting up the emission intensity of which to 366% compared to their randomly oriented counterparts. Moreover, the as-fabricated BaMoO 4 : Eu3+ film shows strong red emission at 615 nm corresponding to the 5 D 0 →7 F 2 transition of Eu3+ with correlated color temperature (CCT) of 2922 °C and ultra-high color purity (nearly 100%). Furthermore, the geometry, size, and luminescence performance of the crystals can be precisely manipulated by tuning the growth temperature, layers of the film, and doping concentration. The present research offers a novel and low-cost route to engineer luminescent films with controllable orientation and enhanced emission intensity, which demonstrate great potentials towards practical applications and industrialization. [ABSTRACT FROM AUTHOR]