Covering the optical spectrum through different rare-earth ion-doping of YAG nanospheres produced by rapid microwave synthesis

In this work, YAG:RE³⁺ (RE = Pr³⁺, Tm³⁺, Tb³⁺, Ce³⁺, Eu³⁺, Nd³⁺, and Er³⁺;Yb³⁺) luminescent nanospheres with tunable photoluminescence (PL) emission were prepared by using fast and energy-saving microwave-assisted synthesis (MWAS). The nanopowders were post-annealed at 1100 °C for 3 h to obtain nanocrystalline phosphors. X-ray diffraction (XRD) analysis confirmed the presence of nanocrystals that were well indexed to the cubic YAG phase. Surface chemical groups were detected using Fourier transform infrared spectroscopy (FTIR). Transmission electron microscopy (TEM) showed that the synthesized samples consist of nanospheres with an average size of ~ 110 nm. The effect of aluminum precursors on the morphology of synthesized nanoparticles is discussed. The produced nanophosphors showed strong emission at different wavelengths (ultraviolet, visible and near-infrared) corresponding to different RE³⁺ ions. Altogether, the merits of spherical morphology and PL emission at various wavelengths endow rare-earth-doped YAG nanoparticles with suitable characteristic for potential applications in the field of nanomedicine (e.g., bioimaging and nanoscintillators), light display systems, optoelectronic devices, and lasers.